feccdceed2
Some BSD platforms do not have this header. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Joelle van Dyne <j@getutm.app> Message-Id: <20210315180341.31638-3-j@getutm.app> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
7593 lines
225 KiB
C
7593 lines
225 KiB
C
/*
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* QEMU System Emulator block driver
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*
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* Copyright (c) 2003 Fabrice Bellard
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* Copyright (c) 2020 Virtuozzo International GmbH.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "qemu/osdep.h"
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#include "block/trace.h"
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#include "block/block_int.h"
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#include "block/blockjob.h"
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#include "block/fuse.h"
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#include "block/nbd.h"
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#include "block/qdict.h"
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#include "qemu/error-report.h"
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#include "block/module_block.h"
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#include "qemu/main-loop.h"
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#include "qemu/module.h"
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#include "qapi/error.h"
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#include "qapi/qmp/qdict.h"
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#include "qapi/qmp/qjson.h"
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#include "qapi/qmp/qnull.h"
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#include "qapi/qmp/qstring.h"
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#include "qapi/qobject-output-visitor.h"
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#include "qapi/qapi-visit-block-core.h"
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#include "sysemu/block-backend.h"
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#include "qemu/notify.h"
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#include "qemu/option.h"
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#include "qemu/coroutine.h"
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#include "block/qapi.h"
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#include "qemu/timer.h"
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#include "qemu/cutils.h"
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#include "qemu/id.h"
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#include "block/coroutines.h"
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#ifdef CONFIG_BSD
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#include <sys/ioctl.h>
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#include <sys/queue.h>
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#if defined(HAVE_SYS_DISK_H)
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#include <sys/disk.h>
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#endif
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#endif
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#ifdef _WIN32
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#include <windows.h>
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#endif
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#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
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static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states =
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QTAILQ_HEAD_INITIALIZER(graph_bdrv_states);
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static QTAILQ_HEAD(, BlockDriverState) all_bdrv_states =
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QTAILQ_HEAD_INITIALIZER(all_bdrv_states);
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static QLIST_HEAD(, BlockDriver) bdrv_drivers =
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QLIST_HEAD_INITIALIZER(bdrv_drivers);
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static BlockDriverState *bdrv_open_inherit(const char *filename,
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const char *reference,
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QDict *options, int flags,
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BlockDriverState *parent,
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const BdrvChildClass *child_class,
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BdrvChildRole child_role,
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Error **errp);
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static void bdrv_replace_child_noperm(BdrvChild *child,
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BlockDriverState *new_bs);
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static void bdrv_remove_filter_or_cow_child(BlockDriverState *bs,
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Transaction *tran);
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static int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
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BlockReopenQueue *queue,
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Transaction *set_backings_tran, Error **errp);
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static void bdrv_reopen_commit(BDRVReopenState *reopen_state);
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static void bdrv_reopen_abort(BDRVReopenState *reopen_state);
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/* If non-zero, use only whitelisted block drivers */
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static int use_bdrv_whitelist;
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#ifdef _WIN32
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static int is_windows_drive_prefix(const char *filename)
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{
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return (((filename[0] >= 'a' && filename[0] <= 'z') ||
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(filename[0] >= 'A' && filename[0] <= 'Z')) &&
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filename[1] == ':');
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}
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int is_windows_drive(const char *filename)
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{
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if (is_windows_drive_prefix(filename) &&
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filename[2] == '\0')
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return 1;
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if (strstart(filename, "\\\\.\\", NULL) ||
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strstart(filename, "//./", NULL))
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return 1;
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return 0;
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}
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#endif
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size_t bdrv_opt_mem_align(BlockDriverState *bs)
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{
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if (!bs || !bs->drv) {
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/* page size or 4k (hdd sector size) should be on the safe side */
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return MAX(4096, qemu_real_host_page_size);
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}
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return bs->bl.opt_mem_alignment;
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}
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size_t bdrv_min_mem_align(BlockDriverState *bs)
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{
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if (!bs || !bs->drv) {
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/* page size or 4k (hdd sector size) should be on the safe side */
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return MAX(4096, qemu_real_host_page_size);
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}
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return bs->bl.min_mem_alignment;
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}
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/* check if the path starts with "<protocol>:" */
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int path_has_protocol(const char *path)
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{
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const char *p;
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#ifdef _WIN32
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if (is_windows_drive(path) ||
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is_windows_drive_prefix(path)) {
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return 0;
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}
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p = path + strcspn(path, ":/\\");
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#else
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p = path + strcspn(path, ":/");
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#endif
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return *p == ':';
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}
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int path_is_absolute(const char *path)
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{
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#ifdef _WIN32
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/* specific case for names like: "\\.\d:" */
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if (is_windows_drive(path) || is_windows_drive_prefix(path)) {
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return 1;
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}
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return (*path == '/' || *path == '\\');
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#else
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return (*path == '/');
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#endif
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}
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/* if filename is absolute, just return its duplicate. Otherwise, build a
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path to it by considering it is relative to base_path. URL are
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supported. */
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char *path_combine(const char *base_path, const char *filename)
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{
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const char *protocol_stripped = NULL;
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const char *p, *p1;
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char *result;
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int len;
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if (path_is_absolute(filename)) {
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return g_strdup(filename);
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}
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if (path_has_protocol(base_path)) {
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protocol_stripped = strchr(base_path, ':');
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if (protocol_stripped) {
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protocol_stripped++;
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}
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}
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p = protocol_stripped ?: base_path;
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p1 = strrchr(base_path, '/');
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#ifdef _WIN32
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{
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const char *p2;
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p2 = strrchr(base_path, '\\');
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if (!p1 || p2 > p1) {
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p1 = p2;
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}
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}
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#endif
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if (p1) {
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p1++;
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} else {
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p1 = base_path;
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}
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if (p1 > p) {
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p = p1;
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}
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len = p - base_path;
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result = g_malloc(len + strlen(filename) + 1);
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memcpy(result, base_path, len);
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strcpy(result + len, filename);
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return result;
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}
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/*
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* Helper function for bdrv_parse_filename() implementations to remove optional
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* protocol prefixes (especially "file:") from a filename and for putting the
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* stripped filename into the options QDict if there is such a prefix.
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*/
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void bdrv_parse_filename_strip_prefix(const char *filename, const char *prefix,
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QDict *options)
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{
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if (strstart(filename, prefix, &filename)) {
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/* Stripping the explicit protocol prefix may result in a protocol
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* prefix being (wrongly) detected (if the filename contains a colon) */
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if (path_has_protocol(filename)) {
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GString *fat_filename;
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/* This means there is some colon before the first slash; therefore,
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* this cannot be an absolute path */
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assert(!path_is_absolute(filename));
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/* And we can thus fix the protocol detection issue by prefixing it
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* by "./" */
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fat_filename = g_string_new("./");
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g_string_append(fat_filename, filename);
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assert(!path_has_protocol(fat_filename->str));
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qdict_put(options, "filename",
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qstring_from_gstring(fat_filename));
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} else {
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/* If no protocol prefix was detected, we can use the shortened
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* filename as-is */
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qdict_put_str(options, "filename", filename);
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}
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}
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}
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/* Returns whether the image file is opened as read-only. Note that this can
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* return false and writing to the image file is still not possible because the
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* image is inactivated. */
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bool bdrv_is_read_only(BlockDriverState *bs)
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{
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return !(bs->open_flags & BDRV_O_RDWR);
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}
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int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only,
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bool ignore_allow_rdw, Error **errp)
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{
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/* Do not set read_only if copy_on_read is enabled */
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if (bs->copy_on_read && read_only) {
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error_setg(errp, "Can't set node '%s' to r/o with copy-on-read enabled",
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bdrv_get_device_or_node_name(bs));
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return -EINVAL;
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}
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/* Do not clear read_only if it is prohibited */
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if (!read_only && !(bs->open_flags & BDRV_O_ALLOW_RDWR) &&
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!ignore_allow_rdw)
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{
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error_setg(errp, "Node '%s' is read only",
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bdrv_get_device_or_node_name(bs));
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return -EPERM;
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}
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return 0;
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}
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/*
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* Called by a driver that can only provide a read-only image.
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*
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* Returns 0 if the node is already read-only or it could switch the node to
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* read-only because BDRV_O_AUTO_RDONLY is set.
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*
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* Returns -EACCES if the node is read-write and BDRV_O_AUTO_RDONLY is not set
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* or bdrv_can_set_read_only() forbids making the node read-only. If @errmsg
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* is not NULL, it is used as the error message for the Error object.
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*/
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int bdrv_apply_auto_read_only(BlockDriverState *bs, const char *errmsg,
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Error **errp)
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{
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int ret = 0;
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if (!(bs->open_flags & BDRV_O_RDWR)) {
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return 0;
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}
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if (!(bs->open_flags & BDRV_O_AUTO_RDONLY)) {
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goto fail;
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}
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ret = bdrv_can_set_read_only(bs, true, false, NULL);
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if (ret < 0) {
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goto fail;
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}
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bs->open_flags &= ~BDRV_O_RDWR;
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return 0;
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fail:
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error_setg(errp, "%s", errmsg ?: "Image is read-only");
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return -EACCES;
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}
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/*
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* If @backing is empty, this function returns NULL without setting
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* @errp. In all other cases, NULL will only be returned with @errp
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* set.
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*
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* Therefore, a return value of NULL without @errp set means that
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* there is no backing file; if @errp is set, there is one but its
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* absolute filename cannot be generated.
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*/
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char *bdrv_get_full_backing_filename_from_filename(const char *backed,
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const char *backing,
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Error **errp)
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{
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if (backing[0] == '\0') {
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return NULL;
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} else if (path_has_protocol(backing) || path_is_absolute(backing)) {
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return g_strdup(backing);
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} else if (backed[0] == '\0' || strstart(backed, "json:", NULL)) {
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error_setg(errp, "Cannot use relative backing file names for '%s'",
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backed);
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return NULL;
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} else {
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return path_combine(backed, backing);
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}
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}
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/*
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* If @filename is empty or NULL, this function returns NULL without
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* setting @errp. In all other cases, NULL will only be returned with
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* @errp set.
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*/
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static char *bdrv_make_absolute_filename(BlockDriverState *relative_to,
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const char *filename, Error **errp)
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{
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char *dir, *full_name;
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if (!filename || filename[0] == '\0') {
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return NULL;
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} else if (path_has_protocol(filename) || path_is_absolute(filename)) {
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return g_strdup(filename);
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}
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dir = bdrv_dirname(relative_to, errp);
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if (!dir) {
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return NULL;
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}
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full_name = g_strconcat(dir, filename, NULL);
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g_free(dir);
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return full_name;
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}
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char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp)
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{
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return bdrv_make_absolute_filename(bs, bs->backing_file, errp);
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}
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void bdrv_register(BlockDriver *bdrv)
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{
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assert(bdrv->format_name);
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QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list);
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}
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BlockDriverState *bdrv_new(void)
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{
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BlockDriverState *bs;
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int i;
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bs = g_new0(BlockDriverState, 1);
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QLIST_INIT(&bs->dirty_bitmaps);
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for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
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QLIST_INIT(&bs->op_blockers[i]);
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}
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qemu_co_mutex_init(&bs->reqs_lock);
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qemu_mutex_init(&bs->dirty_bitmap_mutex);
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bs->refcnt = 1;
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bs->aio_context = qemu_get_aio_context();
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|
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qemu_co_queue_init(&bs->flush_queue);
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|
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for (i = 0; i < bdrv_drain_all_count; i++) {
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bdrv_drained_begin(bs);
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}
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QTAILQ_INSERT_TAIL(&all_bdrv_states, bs, bs_list);
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return bs;
|
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}
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|
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static BlockDriver *bdrv_do_find_format(const char *format_name)
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{
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BlockDriver *drv1;
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|
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QLIST_FOREACH(drv1, &bdrv_drivers, list) {
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if (!strcmp(drv1->format_name, format_name)) {
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return drv1;
|
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}
|
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}
|
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|
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return NULL;
|
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}
|
|
|
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BlockDriver *bdrv_find_format(const char *format_name)
|
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{
|
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BlockDriver *drv1;
|
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int i;
|
|
|
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drv1 = bdrv_do_find_format(format_name);
|
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if (drv1) {
|
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return drv1;
|
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}
|
|
|
|
/* The driver isn't registered, maybe we need to load a module */
|
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for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) {
|
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if (!strcmp(block_driver_modules[i].format_name, format_name)) {
|
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block_module_load_one(block_driver_modules[i].library_name);
|
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break;
|
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}
|
|
}
|
|
|
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return bdrv_do_find_format(format_name);
|
|
}
|
|
|
|
static int bdrv_format_is_whitelisted(const char *format_name, bool read_only)
|
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{
|
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static const char *whitelist_rw[] = {
|
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CONFIG_BDRV_RW_WHITELIST
|
|
NULL
|
|
};
|
|
static const char *whitelist_ro[] = {
|
|
CONFIG_BDRV_RO_WHITELIST
|
|
NULL
|
|
};
|
|
const char **p;
|
|
|
|
if (!whitelist_rw[0] && !whitelist_ro[0]) {
|
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return 1; /* no whitelist, anything goes */
|
|
}
|
|
|
|
for (p = whitelist_rw; *p; p++) {
|
|
if (!strcmp(format_name, *p)) {
|
|
return 1;
|
|
}
|
|
}
|
|
if (read_only) {
|
|
for (p = whitelist_ro; *p; p++) {
|
|
if (!strcmp(format_name, *p)) {
|
|
return 1;
|
|
}
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int bdrv_is_whitelisted(BlockDriver *drv, bool read_only)
|
|
{
|
|
return bdrv_format_is_whitelisted(drv->format_name, read_only);
|
|
}
|
|
|
|
bool bdrv_uses_whitelist(void)
|
|
{
|
|
return use_bdrv_whitelist;
|
|
}
|
|
|
|
typedef struct CreateCo {
|
|
BlockDriver *drv;
|
|
char *filename;
|
|
QemuOpts *opts;
|
|
int ret;
|
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Error *err;
|
|
} CreateCo;
|
|
|
|
static void coroutine_fn bdrv_create_co_entry(void *opaque)
|
|
{
|
|
Error *local_err = NULL;
|
|
int ret;
|
|
|
|
CreateCo *cco = opaque;
|
|
assert(cco->drv);
|
|
|
|
ret = cco->drv->bdrv_co_create_opts(cco->drv,
|
|
cco->filename, cco->opts, &local_err);
|
|
error_propagate(&cco->err, local_err);
|
|
cco->ret = ret;
|
|
}
|
|
|
|
int bdrv_create(BlockDriver *drv, const char* filename,
|
|
QemuOpts *opts, Error **errp)
|
|
{
|
|
int ret;
|
|
|
|
Coroutine *co;
|
|
CreateCo cco = {
|
|
.drv = drv,
|
|
.filename = g_strdup(filename),
|
|
.opts = opts,
|
|
.ret = NOT_DONE,
|
|
.err = NULL,
|
|
};
|
|
|
|
if (!drv->bdrv_co_create_opts) {
|
|
error_setg(errp, "Driver '%s' does not support image creation", drv->format_name);
|
|
ret = -ENOTSUP;
|
|
goto out;
|
|
}
|
|
|
|
if (qemu_in_coroutine()) {
|
|
/* Fast-path if already in coroutine context */
|
|
bdrv_create_co_entry(&cco);
|
|
} else {
|
|
co = qemu_coroutine_create(bdrv_create_co_entry, &cco);
|
|
qemu_coroutine_enter(co);
|
|
while (cco.ret == NOT_DONE) {
|
|
aio_poll(qemu_get_aio_context(), true);
|
|
}
|
|
}
|
|
|
|
ret = cco.ret;
|
|
if (ret < 0) {
|
|
if (cco.err) {
|
|
error_propagate(errp, cco.err);
|
|
} else {
|
|
error_setg_errno(errp, -ret, "Could not create image");
|
|
}
|
|
}
|
|
|
|
out:
|
|
g_free(cco.filename);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* Helper function for bdrv_create_file_fallback(): Resize @blk to at
|
|
* least the given @minimum_size.
|
|
*
|
|
* On success, return @blk's actual length.
|
|
* Otherwise, return -errno.
|
|
*/
|
|
static int64_t create_file_fallback_truncate(BlockBackend *blk,
|
|
int64_t minimum_size, Error **errp)
|
|
{
|
|
Error *local_err = NULL;
|
|
int64_t size;
|
|
int ret;
|
|
|
|
ret = blk_truncate(blk, minimum_size, false, PREALLOC_MODE_OFF, 0,
|
|
&local_err);
|
|
if (ret < 0 && ret != -ENOTSUP) {
|
|
error_propagate(errp, local_err);
|
|
return ret;
|
|
}
|
|
|
|
size = blk_getlength(blk);
|
|
if (size < 0) {
|
|
error_free(local_err);
|
|
error_setg_errno(errp, -size,
|
|
"Failed to inquire the new image file's length");
|
|
return size;
|
|
}
|
|
|
|
if (size < minimum_size) {
|
|
/* Need to grow the image, but we failed to do that */
|
|
error_propagate(errp, local_err);
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
error_free(local_err);
|
|
local_err = NULL;
|
|
|
|
return size;
|
|
}
|
|
|
|
/**
|
|
* Helper function for bdrv_create_file_fallback(): Zero the first
|
|
* sector to remove any potentially pre-existing image header.
|
|
*/
|
|
static int create_file_fallback_zero_first_sector(BlockBackend *blk,
|
|
int64_t current_size,
|
|
Error **errp)
|
|
{
|
|
int64_t bytes_to_clear;
|
|
int ret;
|
|
|
|
bytes_to_clear = MIN(current_size, BDRV_SECTOR_SIZE);
|
|
if (bytes_to_clear) {
|
|
ret = blk_pwrite_zeroes(blk, 0, bytes_to_clear, BDRV_REQ_MAY_UNMAP);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret,
|
|
"Failed to clear the new image's first sector");
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Simple implementation of bdrv_co_create_opts for protocol drivers
|
|
* which only support creation via opening a file
|
|
* (usually existing raw storage device)
|
|
*/
|
|
int coroutine_fn bdrv_co_create_opts_simple(BlockDriver *drv,
|
|
const char *filename,
|
|
QemuOpts *opts,
|
|
Error **errp)
|
|
{
|
|
BlockBackend *blk;
|
|
QDict *options;
|
|
int64_t size = 0;
|
|
char *buf = NULL;
|
|
PreallocMode prealloc;
|
|
Error *local_err = NULL;
|
|
int ret;
|
|
|
|
size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0);
|
|
buf = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC);
|
|
prealloc = qapi_enum_parse(&PreallocMode_lookup, buf,
|
|
PREALLOC_MODE_OFF, &local_err);
|
|
g_free(buf);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (prealloc != PREALLOC_MODE_OFF) {
|
|
error_setg(errp, "Unsupported preallocation mode '%s'",
|
|
PreallocMode_str(prealloc));
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
options = qdict_new();
|
|
qdict_put_str(options, "driver", drv->format_name);
|
|
|
|
blk = blk_new_open(filename, NULL, options,
|
|
BDRV_O_RDWR | BDRV_O_RESIZE, errp);
|
|
if (!blk) {
|
|
error_prepend(errp, "Protocol driver '%s' does not support image "
|
|
"creation, and opening the image failed: ",
|
|
drv->format_name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
size = create_file_fallback_truncate(blk, size, errp);
|
|
if (size < 0) {
|
|
ret = size;
|
|
goto out;
|
|
}
|
|
|
|
ret = create_file_fallback_zero_first_sector(blk, size, errp);
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
|
|
ret = 0;
|
|
out:
|
|
blk_unref(blk);
|
|
return ret;
|
|
}
|
|
|
|
int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp)
|
|
{
|
|
QemuOpts *protocol_opts;
|
|
BlockDriver *drv;
|
|
QDict *qdict;
|
|
int ret;
|
|
|
|
drv = bdrv_find_protocol(filename, true, errp);
|
|
if (drv == NULL) {
|
|
return -ENOENT;
|
|
}
|
|
|
|
if (!drv->create_opts) {
|
|
error_setg(errp, "Driver '%s' does not support image creation",
|
|
drv->format_name);
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
/*
|
|
* 'opts' contains a QemuOptsList with a combination of format and protocol
|
|
* default values.
|
|
*
|
|
* The format properly removes its options, but the default values remain
|
|
* in 'opts->list'. So if the protocol has options with the same name
|
|
* (e.g. rbd has 'cluster_size' as qcow2), it will see the default values
|
|
* of the format, since for overlapping options, the format wins.
|
|
*
|
|
* To avoid this issue, lets convert QemuOpts to QDict, in this way we take
|
|
* only the set options, and then convert it back to QemuOpts, using the
|
|
* create_opts of the protocol. So the new QemuOpts, will contain only the
|
|
* protocol defaults.
|
|
*/
|
|
qdict = qemu_opts_to_qdict(opts, NULL);
|
|
protocol_opts = qemu_opts_from_qdict(drv->create_opts, qdict, errp);
|
|
if (protocol_opts == NULL) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
ret = bdrv_create(drv, filename, protocol_opts, errp);
|
|
out:
|
|
qemu_opts_del(protocol_opts);
|
|
qobject_unref(qdict);
|
|
return ret;
|
|
}
|
|
|
|
int coroutine_fn bdrv_co_delete_file(BlockDriverState *bs, Error **errp)
|
|
{
|
|
Error *local_err = NULL;
|
|
int ret;
|
|
|
|
assert(bs != NULL);
|
|
|
|
if (!bs->drv) {
|
|
error_setg(errp, "Block node '%s' is not opened", bs->filename);
|
|
return -ENOMEDIUM;
|
|
}
|
|
|
|
if (!bs->drv->bdrv_co_delete_file) {
|
|
error_setg(errp, "Driver '%s' does not support image deletion",
|
|
bs->drv->format_name);
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
ret = bs->drv->bdrv_co_delete_file(bs, &local_err);
|
|
if (ret < 0) {
|
|
error_propagate(errp, local_err);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
void coroutine_fn bdrv_co_delete_file_noerr(BlockDriverState *bs)
|
|
{
|
|
Error *local_err = NULL;
|
|
int ret;
|
|
|
|
if (!bs) {
|
|
return;
|
|
}
|
|
|
|
ret = bdrv_co_delete_file(bs, &local_err);
|
|
/*
|
|
* ENOTSUP will happen if the block driver doesn't support
|
|
* the 'bdrv_co_delete_file' interface. This is a predictable
|
|
* scenario and shouldn't be reported back to the user.
|
|
*/
|
|
if (ret == -ENOTSUP) {
|
|
error_free(local_err);
|
|
} else if (ret < 0) {
|
|
error_report_err(local_err);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Try to get @bs's logical and physical block size.
|
|
* On success, store them in @bsz struct and return 0.
|
|
* On failure return -errno.
|
|
* @bs must not be empty.
|
|
*/
|
|
int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
BlockDriverState *filtered = bdrv_filter_bs(bs);
|
|
|
|
if (drv && drv->bdrv_probe_blocksizes) {
|
|
return drv->bdrv_probe_blocksizes(bs, bsz);
|
|
} else if (filtered) {
|
|
return bdrv_probe_blocksizes(filtered, bsz);
|
|
}
|
|
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
/**
|
|
* Try to get @bs's geometry (cyls, heads, sectors).
|
|
* On success, store them in @geo struct and return 0.
|
|
* On failure return -errno.
|
|
* @bs must not be empty.
|
|
*/
|
|
int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
BlockDriverState *filtered = bdrv_filter_bs(bs);
|
|
|
|
if (drv && drv->bdrv_probe_geometry) {
|
|
return drv->bdrv_probe_geometry(bs, geo);
|
|
} else if (filtered) {
|
|
return bdrv_probe_geometry(filtered, geo);
|
|
}
|
|
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
/*
|
|
* Create a uniquely-named empty temporary file.
|
|
* Return 0 upon success, otherwise a negative errno value.
|
|
*/
|
|
int get_tmp_filename(char *filename, int size)
|
|
{
|
|
#ifdef _WIN32
|
|
char temp_dir[MAX_PATH];
|
|
/* GetTempFileName requires that its output buffer (4th param)
|
|
have length MAX_PATH or greater. */
|
|
assert(size >= MAX_PATH);
|
|
return (GetTempPath(MAX_PATH, temp_dir)
|
|
&& GetTempFileName(temp_dir, "qem", 0, filename)
|
|
? 0 : -GetLastError());
|
|
#else
|
|
int fd;
|
|
const char *tmpdir;
|
|
tmpdir = getenv("TMPDIR");
|
|
if (!tmpdir) {
|
|
tmpdir = "/var/tmp";
|
|
}
|
|
if (snprintf(filename, size, "%s/vl.XXXXXX", tmpdir) >= size) {
|
|
return -EOVERFLOW;
|
|
}
|
|
fd = mkstemp(filename);
|
|
if (fd < 0) {
|
|
return -errno;
|
|
}
|
|
if (close(fd) != 0) {
|
|
unlink(filename);
|
|
return -errno;
|
|
}
|
|
return 0;
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Detect host devices. By convention, /dev/cdrom[N] is always
|
|
* recognized as a host CDROM.
|
|
*/
|
|
static BlockDriver *find_hdev_driver(const char *filename)
|
|
{
|
|
int score_max = 0, score;
|
|
BlockDriver *drv = NULL, *d;
|
|
|
|
QLIST_FOREACH(d, &bdrv_drivers, list) {
|
|
if (d->bdrv_probe_device) {
|
|
score = d->bdrv_probe_device(filename);
|
|
if (score > score_max) {
|
|
score_max = score;
|
|
drv = d;
|
|
}
|
|
}
|
|
}
|
|
|
|
return drv;
|
|
}
|
|
|
|
static BlockDriver *bdrv_do_find_protocol(const char *protocol)
|
|
{
|
|
BlockDriver *drv1;
|
|
|
|
QLIST_FOREACH(drv1, &bdrv_drivers, list) {
|
|
if (drv1->protocol_name && !strcmp(drv1->protocol_name, protocol)) {
|
|
return drv1;
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
BlockDriver *bdrv_find_protocol(const char *filename,
|
|
bool allow_protocol_prefix,
|
|
Error **errp)
|
|
{
|
|
BlockDriver *drv1;
|
|
char protocol[128];
|
|
int len;
|
|
const char *p;
|
|
int i;
|
|
|
|
/* TODO Drivers without bdrv_file_open must be specified explicitly */
|
|
|
|
/*
|
|
* XXX(hch): we really should not let host device detection
|
|
* override an explicit protocol specification, but moving this
|
|
* later breaks access to device names with colons in them.
|
|
* Thanks to the brain-dead persistent naming schemes on udev-
|
|
* based Linux systems those actually are quite common.
|
|
*/
|
|
drv1 = find_hdev_driver(filename);
|
|
if (drv1) {
|
|
return drv1;
|
|
}
|
|
|
|
if (!path_has_protocol(filename) || !allow_protocol_prefix) {
|
|
return &bdrv_file;
|
|
}
|
|
|
|
p = strchr(filename, ':');
|
|
assert(p != NULL);
|
|
len = p - filename;
|
|
if (len > sizeof(protocol) - 1)
|
|
len = sizeof(protocol) - 1;
|
|
memcpy(protocol, filename, len);
|
|
protocol[len] = '\0';
|
|
|
|
drv1 = bdrv_do_find_protocol(protocol);
|
|
if (drv1) {
|
|
return drv1;
|
|
}
|
|
|
|
for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) {
|
|
if (block_driver_modules[i].protocol_name &&
|
|
!strcmp(block_driver_modules[i].protocol_name, protocol)) {
|
|
block_module_load_one(block_driver_modules[i].library_name);
|
|
break;
|
|
}
|
|
}
|
|
|
|
drv1 = bdrv_do_find_protocol(protocol);
|
|
if (!drv1) {
|
|
error_setg(errp, "Unknown protocol '%s'", protocol);
|
|
}
|
|
return drv1;
|
|
}
|
|
|
|
/*
|
|
* Guess image format by probing its contents.
|
|
* This is not a good idea when your image is raw (CVE-2008-2004), but
|
|
* we do it anyway for backward compatibility.
|
|
*
|
|
* @buf contains the image's first @buf_size bytes.
|
|
* @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE,
|
|
* but can be smaller if the image file is smaller)
|
|
* @filename is its filename.
|
|
*
|
|
* For all block drivers, call the bdrv_probe() method to get its
|
|
* probing score.
|
|
* Return the first block driver with the highest probing score.
|
|
*/
|
|
BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
|
|
const char *filename)
|
|
{
|
|
int score_max = 0, score;
|
|
BlockDriver *drv = NULL, *d;
|
|
|
|
QLIST_FOREACH(d, &bdrv_drivers, list) {
|
|
if (d->bdrv_probe) {
|
|
score = d->bdrv_probe(buf, buf_size, filename);
|
|
if (score > score_max) {
|
|
score_max = score;
|
|
drv = d;
|
|
}
|
|
}
|
|
}
|
|
|
|
return drv;
|
|
}
|
|
|
|
static int find_image_format(BlockBackend *file, const char *filename,
|
|
BlockDriver **pdrv, Error **errp)
|
|
{
|
|
BlockDriver *drv;
|
|
uint8_t buf[BLOCK_PROBE_BUF_SIZE];
|
|
int ret = 0;
|
|
|
|
/* Return the raw BlockDriver * to scsi-generic devices or empty drives */
|
|
if (blk_is_sg(file) || !blk_is_inserted(file) || blk_getlength(file) == 0) {
|
|
*pdrv = &bdrv_raw;
|
|
return ret;
|
|
}
|
|
|
|
ret = blk_pread(file, 0, buf, sizeof(buf));
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "Could not read image for determining its "
|
|
"format");
|
|
*pdrv = NULL;
|
|
return ret;
|
|
}
|
|
|
|
drv = bdrv_probe_all(buf, ret, filename);
|
|
if (!drv) {
|
|
error_setg(errp, "Could not determine image format: No compatible "
|
|
"driver found");
|
|
ret = -ENOENT;
|
|
}
|
|
*pdrv = drv;
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* Set the current 'total_sectors' value
|
|
* Return 0 on success, -errno on error.
|
|
*/
|
|
int refresh_total_sectors(BlockDriverState *bs, int64_t hint)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
|
|
if (!drv) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
|
|
/* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
|
|
if (bdrv_is_sg(bs))
|
|
return 0;
|
|
|
|
/* query actual device if possible, otherwise just trust the hint */
|
|
if (drv->bdrv_getlength) {
|
|
int64_t length = drv->bdrv_getlength(bs);
|
|
if (length < 0) {
|
|
return length;
|
|
}
|
|
hint = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE);
|
|
}
|
|
|
|
bs->total_sectors = hint;
|
|
|
|
if (bs->total_sectors * BDRV_SECTOR_SIZE > BDRV_MAX_LENGTH) {
|
|
return -EFBIG;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Combines a QDict of new block driver @options with any missing options taken
|
|
* from @old_options, so that leaving out an option defaults to its old value.
|
|
*/
|
|
static void bdrv_join_options(BlockDriverState *bs, QDict *options,
|
|
QDict *old_options)
|
|
{
|
|
if (bs->drv && bs->drv->bdrv_join_options) {
|
|
bs->drv->bdrv_join_options(options, old_options);
|
|
} else {
|
|
qdict_join(options, old_options, false);
|
|
}
|
|
}
|
|
|
|
static BlockdevDetectZeroesOptions bdrv_parse_detect_zeroes(QemuOpts *opts,
|
|
int open_flags,
|
|
Error **errp)
|
|
{
|
|
Error *local_err = NULL;
|
|
char *value = qemu_opt_get_del(opts, "detect-zeroes");
|
|
BlockdevDetectZeroesOptions detect_zeroes =
|
|
qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup, value,
|
|
BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF, &local_err);
|
|
g_free(value);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return detect_zeroes;
|
|
}
|
|
|
|
if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
|
|
!(open_flags & BDRV_O_UNMAP))
|
|
{
|
|
error_setg(errp, "setting detect-zeroes to unmap is not allowed "
|
|
"without setting discard operation to unmap");
|
|
}
|
|
|
|
return detect_zeroes;
|
|
}
|
|
|
|
/**
|
|
* Set open flags for aio engine
|
|
*
|
|
* Return 0 on success, -1 if the engine specified is invalid
|
|
*/
|
|
int bdrv_parse_aio(const char *mode, int *flags)
|
|
{
|
|
if (!strcmp(mode, "threads")) {
|
|
/* do nothing, default */
|
|
} else if (!strcmp(mode, "native")) {
|
|
*flags |= BDRV_O_NATIVE_AIO;
|
|
#ifdef CONFIG_LINUX_IO_URING
|
|
} else if (!strcmp(mode, "io_uring")) {
|
|
*flags |= BDRV_O_IO_URING;
|
|
#endif
|
|
} else {
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Set open flags for a given discard mode
|
|
*
|
|
* Return 0 on success, -1 if the discard mode was invalid.
|
|
*/
|
|
int bdrv_parse_discard_flags(const char *mode, int *flags)
|
|
{
|
|
*flags &= ~BDRV_O_UNMAP;
|
|
|
|
if (!strcmp(mode, "off") || !strcmp(mode, "ignore")) {
|
|
/* do nothing */
|
|
} else if (!strcmp(mode, "on") || !strcmp(mode, "unmap")) {
|
|
*flags |= BDRV_O_UNMAP;
|
|
} else {
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Set open flags for a given cache mode
|
|
*
|
|
* Return 0 on success, -1 if the cache mode was invalid.
|
|
*/
|
|
int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough)
|
|
{
|
|
*flags &= ~BDRV_O_CACHE_MASK;
|
|
|
|
if (!strcmp(mode, "off") || !strcmp(mode, "none")) {
|
|
*writethrough = false;
|
|
*flags |= BDRV_O_NOCACHE;
|
|
} else if (!strcmp(mode, "directsync")) {
|
|
*writethrough = true;
|
|
*flags |= BDRV_O_NOCACHE;
|
|
} else if (!strcmp(mode, "writeback")) {
|
|
*writethrough = false;
|
|
} else if (!strcmp(mode, "unsafe")) {
|
|
*writethrough = false;
|
|
*flags |= BDRV_O_NO_FLUSH;
|
|
} else if (!strcmp(mode, "writethrough")) {
|
|
*writethrough = true;
|
|
} else {
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static char *bdrv_child_get_parent_desc(BdrvChild *c)
|
|
{
|
|
BlockDriverState *parent = c->opaque;
|
|
return g_strdup_printf("node '%s'", bdrv_get_node_name(parent));
|
|
}
|
|
|
|
static void bdrv_child_cb_drained_begin(BdrvChild *child)
|
|
{
|
|
BlockDriverState *bs = child->opaque;
|
|
bdrv_do_drained_begin_quiesce(bs, NULL, false);
|
|
}
|
|
|
|
static bool bdrv_child_cb_drained_poll(BdrvChild *child)
|
|
{
|
|
BlockDriverState *bs = child->opaque;
|
|
return bdrv_drain_poll(bs, false, NULL, false);
|
|
}
|
|
|
|
static void bdrv_child_cb_drained_end(BdrvChild *child,
|
|
int *drained_end_counter)
|
|
{
|
|
BlockDriverState *bs = child->opaque;
|
|
bdrv_drained_end_no_poll(bs, drained_end_counter);
|
|
}
|
|
|
|
static int bdrv_child_cb_inactivate(BdrvChild *child)
|
|
{
|
|
BlockDriverState *bs = child->opaque;
|
|
assert(bs->open_flags & BDRV_O_INACTIVE);
|
|
return 0;
|
|
}
|
|
|
|
static bool bdrv_child_cb_can_set_aio_ctx(BdrvChild *child, AioContext *ctx,
|
|
GSList **ignore, Error **errp)
|
|
{
|
|
BlockDriverState *bs = child->opaque;
|
|
return bdrv_can_set_aio_context(bs, ctx, ignore, errp);
|
|
}
|
|
|
|
static void bdrv_child_cb_set_aio_ctx(BdrvChild *child, AioContext *ctx,
|
|
GSList **ignore)
|
|
{
|
|
BlockDriverState *bs = child->opaque;
|
|
return bdrv_set_aio_context_ignore(bs, ctx, ignore);
|
|
}
|
|
|
|
/*
|
|
* Returns the options and flags that a temporary snapshot should get, based on
|
|
* the originally requested flags (the originally requested image will have
|
|
* flags like a backing file)
|
|
*/
|
|
static void bdrv_temp_snapshot_options(int *child_flags, QDict *child_options,
|
|
int parent_flags, QDict *parent_options)
|
|
{
|
|
*child_flags = (parent_flags & ~BDRV_O_SNAPSHOT) | BDRV_O_TEMPORARY;
|
|
|
|
/* For temporary files, unconditional cache=unsafe is fine */
|
|
qdict_set_default_str(child_options, BDRV_OPT_CACHE_DIRECT, "off");
|
|
qdict_set_default_str(child_options, BDRV_OPT_CACHE_NO_FLUSH, "on");
|
|
|
|
/* Copy the read-only and discard options from the parent */
|
|
qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY);
|
|
qdict_copy_default(child_options, parent_options, BDRV_OPT_DISCARD);
|
|
|
|
/* aio=native doesn't work for cache.direct=off, so disable it for the
|
|
* temporary snapshot */
|
|
*child_flags &= ~BDRV_O_NATIVE_AIO;
|
|
}
|
|
|
|
static void bdrv_backing_attach(BdrvChild *c)
|
|
{
|
|
BlockDriverState *parent = c->opaque;
|
|
BlockDriverState *backing_hd = c->bs;
|
|
|
|
assert(!parent->backing_blocker);
|
|
error_setg(&parent->backing_blocker,
|
|
"node is used as backing hd of '%s'",
|
|
bdrv_get_device_or_node_name(parent));
|
|
|
|
bdrv_refresh_filename(backing_hd);
|
|
|
|
parent->open_flags &= ~BDRV_O_NO_BACKING;
|
|
|
|
bdrv_op_block_all(backing_hd, parent->backing_blocker);
|
|
/* Otherwise we won't be able to commit or stream */
|
|
bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_COMMIT_TARGET,
|
|
parent->backing_blocker);
|
|
bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_STREAM,
|
|
parent->backing_blocker);
|
|
/*
|
|
* We do backup in 3 ways:
|
|
* 1. drive backup
|
|
* The target bs is new opened, and the source is top BDS
|
|
* 2. blockdev backup
|
|
* Both the source and the target are top BDSes.
|
|
* 3. internal backup(used for block replication)
|
|
* Both the source and the target are backing file
|
|
*
|
|
* In case 1 and 2, neither the source nor the target is the backing file.
|
|
* In case 3, we will block the top BDS, so there is only one block job
|
|
* for the top BDS and its backing chain.
|
|
*/
|
|
bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_SOURCE,
|
|
parent->backing_blocker);
|
|
bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_TARGET,
|
|
parent->backing_blocker);
|
|
}
|
|
|
|
static void bdrv_backing_detach(BdrvChild *c)
|
|
{
|
|
BlockDriverState *parent = c->opaque;
|
|
|
|
assert(parent->backing_blocker);
|
|
bdrv_op_unblock_all(c->bs, parent->backing_blocker);
|
|
error_free(parent->backing_blocker);
|
|
parent->backing_blocker = NULL;
|
|
}
|
|
|
|
static int bdrv_backing_update_filename(BdrvChild *c, BlockDriverState *base,
|
|
const char *filename, Error **errp)
|
|
{
|
|
BlockDriverState *parent = c->opaque;
|
|
bool read_only = bdrv_is_read_only(parent);
|
|
int ret;
|
|
|
|
if (read_only) {
|
|
ret = bdrv_reopen_set_read_only(parent, false, errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
ret = bdrv_change_backing_file(parent, filename,
|
|
base->drv ? base->drv->format_name : "",
|
|
false);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "Could not update backing file link");
|
|
}
|
|
|
|
if (read_only) {
|
|
bdrv_reopen_set_read_only(parent, true, NULL);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Returns the options and flags that a generic child of a BDS should
|
|
* get, based on the given options and flags for the parent BDS.
|
|
*/
|
|
static void bdrv_inherited_options(BdrvChildRole role, bool parent_is_format,
|
|
int *child_flags, QDict *child_options,
|
|
int parent_flags, QDict *parent_options)
|
|
{
|
|
int flags = parent_flags;
|
|
|
|
/*
|
|
* First, decide whether to set, clear, or leave BDRV_O_PROTOCOL.
|
|
* Generally, the question to answer is: Should this child be
|
|
* format-probed by default?
|
|
*/
|
|
|
|
/*
|
|
* Pure and non-filtered data children of non-format nodes should
|
|
* be probed by default (even when the node itself has BDRV_O_PROTOCOL
|
|
* set). This only affects a very limited set of drivers (namely
|
|
* quorum and blkverify when this comment was written).
|
|
* Force-clear BDRV_O_PROTOCOL then.
|
|
*/
|
|
if (!parent_is_format &&
|
|
(role & BDRV_CHILD_DATA) &&
|
|
!(role & (BDRV_CHILD_METADATA | BDRV_CHILD_FILTERED)))
|
|
{
|
|
flags &= ~BDRV_O_PROTOCOL;
|
|
}
|
|
|
|
/*
|
|
* All children of format nodes (except for COW children) and all
|
|
* metadata children in general should never be format-probed.
|
|
* Force-set BDRV_O_PROTOCOL then.
|
|
*/
|
|
if ((parent_is_format && !(role & BDRV_CHILD_COW)) ||
|
|
(role & BDRV_CHILD_METADATA))
|
|
{
|
|
flags |= BDRV_O_PROTOCOL;
|
|
}
|
|
|
|
/*
|
|
* If the cache mode isn't explicitly set, inherit direct and no-flush from
|
|
* the parent.
|
|
*/
|
|
qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT);
|
|
qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH);
|
|
qdict_copy_default(child_options, parent_options, BDRV_OPT_FORCE_SHARE);
|
|
|
|
if (role & BDRV_CHILD_COW) {
|
|
/* backing files are opened read-only by default */
|
|
qdict_set_default_str(child_options, BDRV_OPT_READ_ONLY, "on");
|
|
qdict_set_default_str(child_options, BDRV_OPT_AUTO_READ_ONLY, "off");
|
|
} else {
|
|
/* Inherit the read-only option from the parent if it's not set */
|
|
qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY);
|
|
qdict_copy_default(child_options, parent_options,
|
|
BDRV_OPT_AUTO_READ_ONLY);
|
|
}
|
|
|
|
/*
|
|
* bdrv_co_pdiscard() respects unmap policy for the parent, so we
|
|
* can default to enable it on lower layers regardless of the
|
|
* parent option.
|
|
*/
|
|
qdict_set_default_str(child_options, BDRV_OPT_DISCARD, "unmap");
|
|
|
|
/* Clear flags that only apply to the top layer */
|
|
flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_COPY_ON_READ);
|
|
|
|
if (role & BDRV_CHILD_METADATA) {
|
|
flags &= ~BDRV_O_NO_IO;
|
|
}
|
|
if (role & BDRV_CHILD_COW) {
|
|
flags &= ~BDRV_O_TEMPORARY;
|
|
}
|
|
|
|
*child_flags = flags;
|
|
}
|
|
|
|
static void bdrv_child_cb_attach(BdrvChild *child)
|
|
{
|
|
BlockDriverState *bs = child->opaque;
|
|
|
|
if (child->role & BDRV_CHILD_COW) {
|
|
bdrv_backing_attach(child);
|
|
}
|
|
|
|
bdrv_apply_subtree_drain(child, bs);
|
|
}
|
|
|
|
static void bdrv_child_cb_detach(BdrvChild *child)
|
|
{
|
|
BlockDriverState *bs = child->opaque;
|
|
|
|
if (child->role & BDRV_CHILD_COW) {
|
|
bdrv_backing_detach(child);
|
|
}
|
|
|
|
bdrv_unapply_subtree_drain(child, bs);
|
|
}
|
|
|
|
static int bdrv_child_cb_update_filename(BdrvChild *c, BlockDriverState *base,
|
|
const char *filename, Error **errp)
|
|
{
|
|
if (c->role & BDRV_CHILD_COW) {
|
|
return bdrv_backing_update_filename(c, base, filename, errp);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
AioContext *child_of_bds_get_parent_aio_context(BdrvChild *c)
|
|
{
|
|
BlockDriverState *bs = c->opaque;
|
|
|
|
return bdrv_get_aio_context(bs);
|
|
}
|
|
|
|
const BdrvChildClass child_of_bds = {
|
|
.parent_is_bds = true,
|
|
.get_parent_desc = bdrv_child_get_parent_desc,
|
|
.inherit_options = bdrv_inherited_options,
|
|
.drained_begin = bdrv_child_cb_drained_begin,
|
|
.drained_poll = bdrv_child_cb_drained_poll,
|
|
.drained_end = bdrv_child_cb_drained_end,
|
|
.attach = bdrv_child_cb_attach,
|
|
.detach = bdrv_child_cb_detach,
|
|
.inactivate = bdrv_child_cb_inactivate,
|
|
.can_set_aio_ctx = bdrv_child_cb_can_set_aio_ctx,
|
|
.set_aio_ctx = bdrv_child_cb_set_aio_ctx,
|
|
.update_filename = bdrv_child_cb_update_filename,
|
|
.get_parent_aio_context = child_of_bds_get_parent_aio_context,
|
|
};
|
|
|
|
AioContext *bdrv_child_get_parent_aio_context(BdrvChild *c)
|
|
{
|
|
return c->klass->get_parent_aio_context(c);
|
|
}
|
|
|
|
static int bdrv_open_flags(BlockDriverState *bs, int flags)
|
|
{
|
|
int open_flags = flags;
|
|
|
|
/*
|
|
* Clear flags that are internal to the block layer before opening the
|
|
* image.
|
|
*/
|
|
open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_PROTOCOL);
|
|
|
|
return open_flags;
|
|
}
|
|
|
|
static void update_flags_from_options(int *flags, QemuOpts *opts)
|
|
{
|
|
*flags &= ~(BDRV_O_CACHE_MASK | BDRV_O_RDWR | BDRV_O_AUTO_RDONLY);
|
|
|
|
if (qemu_opt_get_bool_del(opts, BDRV_OPT_CACHE_NO_FLUSH, false)) {
|
|
*flags |= BDRV_O_NO_FLUSH;
|
|
}
|
|
|
|
if (qemu_opt_get_bool_del(opts, BDRV_OPT_CACHE_DIRECT, false)) {
|
|
*flags |= BDRV_O_NOCACHE;
|
|
}
|
|
|
|
if (!qemu_opt_get_bool_del(opts, BDRV_OPT_READ_ONLY, false)) {
|
|
*flags |= BDRV_O_RDWR;
|
|
}
|
|
|
|
if (qemu_opt_get_bool_del(opts, BDRV_OPT_AUTO_READ_ONLY, false)) {
|
|
*flags |= BDRV_O_AUTO_RDONLY;
|
|
}
|
|
}
|
|
|
|
static void update_options_from_flags(QDict *options, int flags)
|
|
{
|
|
if (!qdict_haskey(options, BDRV_OPT_CACHE_DIRECT)) {
|
|
qdict_put_bool(options, BDRV_OPT_CACHE_DIRECT, flags & BDRV_O_NOCACHE);
|
|
}
|
|
if (!qdict_haskey(options, BDRV_OPT_CACHE_NO_FLUSH)) {
|
|
qdict_put_bool(options, BDRV_OPT_CACHE_NO_FLUSH,
|
|
flags & BDRV_O_NO_FLUSH);
|
|
}
|
|
if (!qdict_haskey(options, BDRV_OPT_READ_ONLY)) {
|
|
qdict_put_bool(options, BDRV_OPT_READ_ONLY, !(flags & BDRV_O_RDWR));
|
|
}
|
|
if (!qdict_haskey(options, BDRV_OPT_AUTO_READ_ONLY)) {
|
|
qdict_put_bool(options, BDRV_OPT_AUTO_READ_ONLY,
|
|
flags & BDRV_O_AUTO_RDONLY);
|
|
}
|
|
}
|
|
|
|
static void bdrv_assign_node_name(BlockDriverState *bs,
|
|
const char *node_name,
|
|
Error **errp)
|
|
{
|
|
char *gen_node_name = NULL;
|
|
|
|
if (!node_name) {
|
|
node_name = gen_node_name = id_generate(ID_BLOCK);
|
|
} else if (!id_wellformed(node_name)) {
|
|
/*
|
|
* Check for empty string or invalid characters, but not if it is
|
|
* generated (generated names use characters not available to the user)
|
|
*/
|
|
error_setg(errp, "Invalid node-name: '%s'", node_name);
|
|
return;
|
|
}
|
|
|
|
/* takes care of avoiding namespaces collisions */
|
|
if (blk_by_name(node_name)) {
|
|
error_setg(errp, "node-name=%s is conflicting with a device id",
|
|
node_name);
|
|
goto out;
|
|
}
|
|
|
|
/* takes care of avoiding duplicates node names */
|
|
if (bdrv_find_node(node_name)) {
|
|
error_setg(errp, "Duplicate nodes with node-name='%s'", node_name);
|
|
goto out;
|
|
}
|
|
|
|
/* Make sure that the node name isn't truncated */
|
|
if (strlen(node_name) >= sizeof(bs->node_name)) {
|
|
error_setg(errp, "Node name too long");
|
|
goto out;
|
|
}
|
|
|
|
/* copy node name into the bs and insert it into the graph list */
|
|
pstrcpy(bs->node_name, sizeof(bs->node_name), node_name);
|
|
QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs, node_list);
|
|
out:
|
|
g_free(gen_node_name);
|
|
}
|
|
|
|
static int bdrv_open_driver(BlockDriverState *bs, BlockDriver *drv,
|
|
const char *node_name, QDict *options,
|
|
int open_flags, Error **errp)
|
|
{
|
|
Error *local_err = NULL;
|
|
int i, ret;
|
|
|
|
bdrv_assign_node_name(bs, node_name, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return -EINVAL;
|
|
}
|
|
|
|
bs->drv = drv;
|
|
bs->opaque = g_malloc0(drv->instance_size);
|
|
|
|
if (drv->bdrv_file_open) {
|
|
assert(!drv->bdrv_needs_filename || bs->filename[0]);
|
|
ret = drv->bdrv_file_open(bs, options, open_flags, &local_err);
|
|
} else if (drv->bdrv_open) {
|
|
ret = drv->bdrv_open(bs, options, open_flags, &local_err);
|
|
} else {
|
|
ret = 0;
|
|
}
|
|
|
|
if (ret < 0) {
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
} else if (bs->filename[0]) {
|
|
error_setg_errno(errp, -ret, "Could not open '%s'", bs->filename);
|
|
} else {
|
|
error_setg_errno(errp, -ret, "Could not open image");
|
|
}
|
|
goto open_failed;
|
|
}
|
|
|
|
ret = refresh_total_sectors(bs, bs->total_sectors);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "Could not refresh total sector count");
|
|
return ret;
|
|
}
|
|
|
|
bdrv_refresh_limits(bs, NULL, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return -EINVAL;
|
|
}
|
|
|
|
assert(bdrv_opt_mem_align(bs) != 0);
|
|
assert(bdrv_min_mem_align(bs) != 0);
|
|
assert(is_power_of_2(bs->bl.request_alignment));
|
|
|
|
for (i = 0; i < bs->quiesce_counter; i++) {
|
|
if (drv->bdrv_co_drain_begin) {
|
|
drv->bdrv_co_drain_begin(bs);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
open_failed:
|
|
bs->drv = NULL;
|
|
if (bs->file != NULL) {
|
|
bdrv_unref_child(bs, bs->file);
|
|
bs->file = NULL;
|
|
}
|
|
g_free(bs->opaque);
|
|
bs->opaque = NULL;
|
|
return ret;
|
|
}
|
|
|
|
BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name,
|
|
int flags, Error **errp)
|
|
{
|
|
BlockDriverState *bs;
|
|
int ret;
|
|
|
|
bs = bdrv_new();
|
|
bs->open_flags = flags;
|
|
bs->explicit_options = qdict_new();
|
|
bs->options = qdict_new();
|
|
bs->opaque = NULL;
|
|
|
|
update_options_from_flags(bs->options, flags);
|
|
|
|
ret = bdrv_open_driver(bs, drv, node_name, bs->options, flags, errp);
|
|
if (ret < 0) {
|
|
qobject_unref(bs->explicit_options);
|
|
bs->explicit_options = NULL;
|
|
qobject_unref(bs->options);
|
|
bs->options = NULL;
|
|
bdrv_unref(bs);
|
|
return NULL;
|
|
}
|
|
|
|
return bs;
|
|
}
|
|
|
|
QemuOptsList bdrv_runtime_opts = {
|
|
.name = "bdrv_common",
|
|
.head = QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts.head),
|
|
.desc = {
|
|
{
|
|
.name = "node-name",
|
|
.type = QEMU_OPT_STRING,
|
|
.help = "Node name of the block device node",
|
|
},
|
|
{
|
|
.name = "driver",
|
|
.type = QEMU_OPT_STRING,
|
|
.help = "Block driver to use for the node",
|
|
},
|
|
{
|
|
.name = BDRV_OPT_CACHE_DIRECT,
|
|
.type = QEMU_OPT_BOOL,
|
|
.help = "Bypass software writeback cache on the host",
|
|
},
|
|
{
|
|
.name = BDRV_OPT_CACHE_NO_FLUSH,
|
|
.type = QEMU_OPT_BOOL,
|
|
.help = "Ignore flush requests",
|
|
},
|
|
{
|
|
.name = BDRV_OPT_READ_ONLY,
|
|
.type = QEMU_OPT_BOOL,
|
|
.help = "Node is opened in read-only mode",
|
|
},
|
|
{
|
|
.name = BDRV_OPT_AUTO_READ_ONLY,
|
|
.type = QEMU_OPT_BOOL,
|
|
.help = "Node can become read-only if opening read-write fails",
|
|
},
|
|
{
|
|
.name = "detect-zeroes",
|
|
.type = QEMU_OPT_STRING,
|
|
.help = "try to optimize zero writes (off, on, unmap)",
|
|
},
|
|
{
|
|
.name = BDRV_OPT_DISCARD,
|
|
.type = QEMU_OPT_STRING,
|
|
.help = "discard operation (ignore/off, unmap/on)",
|
|
},
|
|
{
|
|
.name = BDRV_OPT_FORCE_SHARE,
|
|
.type = QEMU_OPT_BOOL,
|
|
.help = "always accept other writers (default: off)",
|
|
},
|
|
{ /* end of list */ }
|
|
},
|
|
};
|
|
|
|
QemuOptsList bdrv_create_opts_simple = {
|
|
.name = "simple-create-opts",
|
|
.head = QTAILQ_HEAD_INITIALIZER(bdrv_create_opts_simple.head),
|
|
.desc = {
|
|
{
|
|
.name = BLOCK_OPT_SIZE,
|
|
.type = QEMU_OPT_SIZE,
|
|
.help = "Virtual disk size"
|
|
},
|
|
{
|
|
.name = BLOCK_OPT_PREALLOC,
|
|
.type = QEMU_OPT_STRING,
|
|
.help = "Preallocation mode (allowed values: off)"
|
|
},
|
|
{ /* end of list */ }
|
|
}
|
|
};
|
|
|
|
/*
|
|
* Common part for opening disk images and files
|
|
*
|
|
* Removes all processed options from *options.
|
|
*/
|
|
static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file,
|
|
QDict *options, Error **errp)
|
|
{
|
|
int ret, open_flags;
|
|
const char *filename;
|
|
const char *driver_name = NULL;
|
|
const char *node_name = NULL;
|
|
const char *discard;
|
|
QemuOpts *opts;
|
|
BlockDriver *drv;
|
|
Error *local_err = NULL;
|
|
bool ro;
|
|
|
|
assert(bs->file == NULL);
|
|
assert(options != NULL && bs->options != options);
|
|
|
|
opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort);
|
|
if (!qemu_opts_absorb_qdict(opts, options, errp)) {
|
|
ret = -EINVAL;
|
|
goto fail_opts;
|
|
}
|
|
|
|
update_flags_from_options(&bs->open_flags, opts);
|
|
|
|
driver_name = qemu_opt_get(opts, "driver");
|
|
drv = bdrv_find_format(driver_name);
|
|
assert(drv != NULL);
|
|
|
|
bs->force_share = qemu_opt_get_bool(opts, BDRV_OPT_FORCE_SHARE, false);
|
|
|
|
if (bs->force_share && (bs->open_flags & BDRV_O_RDWR)) {
|
|
error_setg(errp,
|
|
BDRV_OPT_FORCE_SHARE
|
|
"=on can only be used with read-only images");
|
|
ret = -EINVAL;
|
|
goto fail_opts;
|
|
}
|
|
|
|
if (file != NULL) {
|
|
bdrv_refresh_filename(blk_bs(file));
|
|
filename = blk_bs(file)->filename;
|
|
} else {
|
|
/*
|
|
* Caution: while qdict_get_try_str() is fine, getting
|
|
* non-string types would require more care. When @options
|
|
* come from -blockdev or blockdev_add, its members are typed
|
|
* according to the QAPI schema, but when they come from
|
|
* -drive, they're all QString.
|
|
*/
|
|
filename = qdict_get_try_str(options, "filename");
|
|
}
|
|
|
|
if (drv->bdrv_needs_filename && (!filename || !filename[0])) {
|
|
error_setg(errp, "The '%s' block driver requires a file name",
|
|
drv->format_name);
|
|
ret = -EINVAL;
|
|
goto fail_opts;
|
|
}
|
|
|
|
trace_bdrv_open_common(bs, filename ?: "", bs->open_flags,
|
|
drv->format_name);
|
|
|
|
ro = bdrv_is_read_only(bs);
|
|
|
|
if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, ro)) {
|
|
if (!ro && bdrv_is_whitelisted(drv, true)) {
|
|
ret = bdrv_apply_auto_read_only(bs, NULL, NULL);
|
|
} else {
|
|
ret = -ENOTSUP;
|
|
}
|
|
if (ret < 0) {
|
|
error_setg(errp,
|
|
!ro && bdrv_is_whitelisted(drv, true)
|
|
? "Driver '%s' can only be used for read-only devices"
|
|
: "Driver '%s' is not whitelisted",
|
|
drv->format_name);
|
|
goto fail_opts;
|
|
}
|
|
}
|
|
|
|
/* bdrv_new() and bdrv_close() make it so */
|
|
assert(qatomic_read(&bs->copy_on_read) == 0);
|
|
|
|
if (bs->open_flags & BDRV_O_COPY_ON_READ) {
|
|
if (!ro) {
|
|
bdrv_enable_copy_on_read(bs);
|
|
} else {
|
|
error_setg(errp, "Can't use copy-on-read on read-only device");
|
|
ret = -EINVAL;
|
|
goto fail_opts;
|
|
}
|
|
}
|
|
|
|
discard = qemu_opt_get(opts, BDRV_OPT_DISCARD);
|
|
if (discard != NULL) {
|
|
if (bdrv_parse_discard_flags(discard, &bs->open_flags) != 0) {
|
|
error_setg(errp, "Invalid discard option");
|
|
ret = -EINVAL;
|
|
goto fail_opts;
|
|
}
|
|
}
|
|
|
|
bs->detect_zeroes =
|
|
bdrv_parse_detect_zeroes(opts, bs->open_flags, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
ret = -EINVAL;
|
|
goto fail_opts;
|
|
}
|
|
|
|
if (filename != NULL) {
|
|
pstrcpy(bs->filename, sizeof(bs->filename), filename);
|
|
} else {
|
|
bs->filename[0] = '\0';
|
|
}
|
|
pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), bs->filename);
|
|
|
|
/* Open the image, either directly or using a protocol */
|
|
open_flags = bdrv_open_flags(bs, bs->open_flags);
|
|
node_name = qemu_opt_get(opts, "node-name");
|
|
|
|
assert(!drv->bdrv_file_open || file == NULL);
|
|
ret = bdrv_open_driver(bs, drv, node_name, options, open_flags, errp);
|
|
if (ret < 0) {
|
|
goto fail_opts;
|
|
}
|
|
|
|
qemu_opts_del(opts);
|
|
return 0;
|
|
|
|
fail_opts:
|
|
qemu_opts_del(opts);
|
|
return ret;
|
|
}
|
|
|
|
static QDict *parse_json_filename(const char *filename, Error **errp)
|
|
{
|
|
QObject *options_obj;
|
|
QDict *options;
|
|
int ret;
|
|
|
|
ret = strstart(filename, "json:", &filename);
|
|
assert(ret);
|
|
|
|
options_obj = qobject_from_json(filename, errp);
|
|
if (!options_obj) {
|
|
error_prepend(errp, "Could not parse the JSON options: ");
|
|
return NULL;
|
|
}
|
|
|
|
options = qobject_to(QDict, options_obj);
|
|
if (!options) {
|
|
qobject_unref(options_obj);
|
|
error_setg(errp, "Invalid JSON object given");
|
|
return NULL;
|
|
}
|
|
|
|
qdict_flatten(options);
|
|
|
|
return options;
|
|
}
|
|
|
|
static void parse_json_protocol(QDict *options, const char **pfilename,
|
|
Error **errp)
|
|
{
|
|
QDict *json_options;
|
|
Error *local_err = NULL;
|
|
|
|
/* Parse json: pseudo-protocol */
|
|
if (!*pfilename || !g_str_has_prefix(*pfilename, "json:")) {
|
|
return;
|
|
}
|
|
|
|
json_options = parse_json_filename(*pfilename, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return;
|
|
}
|
|
|
|
/* Options given in the filename have lower priority than options
|
|
* specified directly */
|
|
qdict_join(options, json_options, false);
|
|
qobject_unref(json_options);
|
|
*pfilename = NULL;
|
|
}
|
|
|
|
/*
|
|
* Fills in default options for opening images and converts the legacy
|
|
* filename/flags pair to option QDict entries.
|
|
* The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a
|
|
* block driver has been specified explicitly.
|
|
*/
|
|
static int bdrv_fill_options(QDict **options, const char *filename,
|
|
int *flags, Error **errp)
|
|
{
|
|
const char *drvname;
|
|
bool protocol = *flags & BDRV_O_PROTOCOL;
|
|
bool parse_filename = false;
|
|
BlockDriver *drv = NULL;
|
|
Error *local_err = NULL;
|
|
|
|
/*
|
|
* Caution: while qdict_get_try_str() is fine, getting non-string
|
|
* types would require more care. When @options come from
|
|
* -blockdev or blockdev_add, its members are typed according to
|
|
* the QAPI schema, but when they come from -drive, they're all
|
|
* QString.
|
|
*/
|
|
drvname = qdict_get_try_str(*options, "driver");
|
|
if (drvname) {
|
|
drv = bdrv_find_format(drvname);
|
|
if (!drv) {
|
|
error_setg(errp, "Unknown driver '%s'", drvname);
|
|
return -ENOENT;
|
|
}
|
|
/* If the user has explicitly specified the driver, this choice should
|
|
* override the BDRV_O_PROTOCOL flag */
|
|
protocol = drv->bdrv_file_open;
|
|
}
|
|
|
|
if (protocol) {
|
|
*flags |= BDRV_O_PROTOCOL;
|
|
} else {
|
|
*flags &= ~BDRV_O_PROTOCOL;
|
|
}
|
|
|
|
/* Translate cache options from flags into options */
|
|
update_options_from_flags(*options, *flags);
|
|
|
|
/* Fetch the file name from the options QDict if necessary */
|
|
if (protocol && filename) {
|
|
if (!qdict_haskey(*options, "filename")) {
|
|
qdict_put_str(*options, "filename", filename);
|
|
parse_filename = true;
|
|
} else {
|
|
error_setg(errp, "Can't specify 'file' and 'filename' options at "
|
|
"the same time");
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
/* Find the right block driver */
|
|
/* See cautionary note on accessing @options above */
|
|
filename = qdict_get_try_str(*options, "filename");
|
|
|
|
if (!drvname && protocol) {
|
|
if (filename) {
|
|
drv = bdrv_find_protocol(filename, parse_filename, errp);
|
|
if (!drv) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
drvname = drv->format_name;
|
|
qdict_put_str(*options, "driver", drvname);
|
|
} else {
|
|
error_setg(errp, "Must specify either driver or file");
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
assert(drv || !protocol);
|
|
|
|
/* Driver-specific filename parsing */
|
|
if (drv && drv->bdrv_parse_filename && parse_filename) {
|
|
drv->bdrv_parse_filename(filename, *options, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (!drv->bdrv_needs_filename) {
|
|
qdict_del(*options, "filename");
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
typedef struct BlockReopenQueueEntry {
|
|
bool prepared;
|
|
bool perms_checked;
|
|
BDRVReopenState state;
|
|
QTAILQ_ENTRY(BlockReopenQueueEntry) entry;
|
|
} BlockReopenQueueEntry;
|
|
|
|
/*
|
|
* Return the flags that @bs will have after the reopens in @q have
|
|
* successfully completed. If @q is NULL (or @bs is not contained in @q),
|
|
* return the current flags.
|
|
*/
|
|
static int bdrv_reopen_get_flags(BlockReopenQueue *q, BlockDriverState *bs)
|
|
{
|
|
BlockReopenQueueEntry *entry;
|
|
|
|
if (q != NULL) {
|
|
QTAILQ_FOREACH(entry, q, entry) {
|
|
if (entry->state.bs == bs) {
|
|
return entry->state.flags;
|
|
}
|
|
}
|
|
}
|
|
|
|
return bs->open_flags;
|
|
}
|
|
|
|
/* Returns whether the image file can be written to after the reopen queue @q
|
|
* has been successfully applied, or right now if @q is NULL. */
|
|
static bool bdrv_is_writable_after_reopen(BlockDriverState *bs,
|
|
BlockReopenQueue *q)
|
|
{
|
|
int flags = bdrv_reopen_get_flags(q, bs);
|
|
|
|
return (flags & (BDRV_O_RDWR | BDRV_O_INACTIVE)) == BDRV_O_RDWR;
|
|
}
|
|
|
|
/*
|
|
* Return whether the BDS can be written to. This is not necessarily
|
|
* the same as !bdrv_is_read_only(bs), as inactivated images may not
|
|
* be written to but do not count as read-only images.
|
|
*/
|
|
bool bdrv_is_writable(BlockDriverState *bs)
|
|
{
|
|
return bdrv_is_writable_after_reopen(bs, NULL);
|
|
}
|
|
|
|
static char *bdrv_child_user_desc(BdrvChild *c)
|
|
{
|
|
return c->klass->get_parent_desc(c);
|
|
}
|
|
|
|
/*
|
|
* Check that @a allows everything that @b needs. @a and @b must reference same
|
|
* child node.
|
|
*/
|
|
static bool bdrv_a_allow_b(BdrvChild *a, BdrvChild *b, Error **errp)
|
|
{
|
|
const char *child_bs_name;
|
|
g_autofree char *a_user = NULL;
|
|
g_autofree char *b_user = NULL;
|
|
g_autofree char *perms = NULL;
|
|
|
|
assert(a->bs);
|
|
assert(a->bs == b->bs);
|
|
|
|
if ((b->perm & a->shared_perm) == b->perm) {
|
|
return true;
|
|
}
|
|
|
|
child_bs_name = bdrv_get_node_name(b->bs);
|
|
a_user = bdrv_child_user_desc(a);
|
|
b_user = bdrv_child_user_desc(b);
|
|
perms = bdrv_perm_names(b->perm & ~a->shared_perm);
|
|
|
|
error_setg(errp, "Permission conflict on node '%s': permissions '%s' are "
|
|
"both required by %s (uses node '%s' as '%s' child) and "
|
|
"unshared by %s (uses node '%s' as '%s' child).",
|
|
child_bs_name, perms,
|
|
b_user, child_bs_name, b->name,
|
|
a_user, child_bs_name, a->name);
|
|
|
|
return false;
|
|
}
|
|
|
|
static bool bdrv_parent_perms_conflict(BlockDriverState *bs, Error **errp)
|
|
{
|
|
BdrvChild *a, *b;
|
|
|
|
/*
|
|
* During the loop we'll look at each pair twice. That's correct because
|
|
* bdrv_a_allow_b() is asymmetric and we should check each pair in both
|
|
* directions.
|
|
*/
|
|
QLIST_FOREACH(a, &bs->parents, next_parent) {
|
|
QLIST_FOREACH(b, &bs->parents, next_parent) {
|
|
if (a == b) {
|
|
continue;
|
|
}
|
|
|
|
if (!bdrv_a_allow_b(a, b, errp)) {
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static void bdrv_child_perm(BlockDriverState *bs, BlockDriverState *child_bs,
|
|
BdrvChild *c, BdrvChildRole role,
|
|
BlockReopenQueue *reopen_queue,
|
|
uint64_t parent_perm, uint64_t parent_shared,
|
|
uint64_t *nperm, uint64_t *nshared)
|
|
{
|
|
assert(bs->drv && bs->drv->bdrv_child_perm);
|
|
bs->drv->bdrv_child_perm(bs, c, role, reopen_queue,
|
|
parent_perm, parent_shared,
|
|
nperm, nshared);
|
|
/* TODO Take force_share from reopen_queue */
|
|
if (child_bs && child_bs->force_share) {
|
|
*nshared = BLK_PERM_ALL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Adds the whole subtree of @bs (including @bs itself) to the @list (except for
|
|
* nodes that are already in the @list, of course) so that final list is
|
|
* topologically sorted. Return the result (GSList @list object is updated, so
|
|
* don't use old reference after function call).
|
|
*
|
|
* On function start @list must be already topologically sorted and for any node
|
|
* in the @list the whole subtree of the node must be in the @list as well. The
|
|
* simplest way to satisfy this criteria: use only result of
|
|
* bdrv_topological_dfs() or NULL as @list parameter.
|
|
*/
|
|
static GSList *bdrv_topological_dfs(GSList *list, GHashTable *found,
|
|
BlockDriverState *bs)
|
|
{
|
|
BdrvChild *child;
|
|
g_autoptr(GHashTable) local_found = NULL;
|
|
|
|
if (!found) {
|
|
assert(!list);
|
|
found = local_found = g_hash_table_new(NULL, NULL);
|
|
}
|
|
|
|
if (g_hash_table_contains(found, bs)) {
|
|
return list;
|
|
}
|
|
g_hash_table_add(found, bs);
|
|
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
list = bdrv_topological_dfs(list, found, child->bs);
|
|
}
|
|
|
|
return g_slist_prepend(list, bs);
|
|
}
|
|
|
|
typedef struct BdrvChildSetPermState {
|
|
BdrvChild *child;
|
|
uint64_t old_perm;
|
|
uint64_t old_shared_perm;
|
|
} BdrvChildSetPermState;
|
|
|
|
static void bdrv_child_set_perm_abort(void *opaque)
|
|
{
|
|
BdrvChildSetPermState *s = opaque;
|
|
|
|
s->child->perm = s->old_perm;
|
|
s->child->shared_perm = s->old_shared_perm;
|
|
}
|
|
|
|
static TransactionActionDrv bdrv_child_set_pem_drv = {
|
|
.abort = bdrv_child_set_perm_abort,
|
|
.clean = g_free,
|
|
};
|
|
|
|
static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm,
|
|
uint64_t shared, Transaction *tran)
|
|
{
|
|
BdrvChildSetPermState *s = g_new(BdrvChildSetPermState, 1);
|
|
|
|
*s = (BdrvChildSetPermState) {
|
|
.child = c,
|
|
.old_perm = c->perm,
|
|
.old_shared_perm = c->shared_perm,
|
|
};
|
|
|
|
c->perm = perm;
|
|
c->shared_perm = shared;
|
|
|
|
tran_add(tran, &bdrv_child_set_pem_drv, s);
|
|
}
|
|
|
|
static void bdrv_drv_set_perm_commit(void *opaque)
|
|
{
|
|
BlockDriverState *bs = opaque;
|
|
uint64_t cumulative_perms, cumulative_shared_perms;
|
|
|
|
if (bs->drv->bdrv_set_perm) {
|
|
bdrv_get_cumulative_perm(bs, &cumulative_perms,
|
|
&cumulative_shared_perms);
|
|
bs->drv->bdrv_set_perm(bs, cumulative_perms, cumulative_shared_perms);
|
|
}
|
|
}
|
|
|
|
static void bdrv_drv_set_perm_abort(void *opaque)
|
|
{
|
|
BlockDriverState *bs = opaque;
|
|
|
|
if (bs->drv->bdrv_abort_perm_update) {
|
|
bs->drv->bdrv_abort_perm_update(bs);
|
|
}
|
|
}
|
|
|
|
TransactionActionDrv bdrv_drv_set_perm_drv = {
|
|
.abort = bdrv_drv_set_perm_abort,
|
|
.commit = bdrv_drv_set_perm_commit,
|
|
};
|
|
|
|
static int bdrv_drv_set_perm(BlockDriverState *bs, uint64_t perm,
|
|
uint64_t shared_perm, Transaction *tran,
|
|
Error **errp)
|
|
{
|
|
if (!bs->drv) {
|
|
return 0;
|
|
}
|
|
|
|
if (bs->drv->bdrv_check_perm) {
|
|
int ret = bs->drv->bdrv_check_perm(bs, perm, shared_perm, errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
if (tran) {
|
|
tran_add(tran, &bdrv_drv_set_perm_drv, bs);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
typedef struct BdrvReplaceChildState {
|
|
BdrvChild *child;
|
|
BlockDriverState *old_bs;
|
|
} BdrvReplaceChildState;
|
|
|
|
static void bdrv_replace_child_commit(void *opaque)
|
|
{
|
|
BdrvReplaceChildState *s = opaque;
|
|
|
|
bdrv_unref(s->old_bs);
|
|
}
|
|
|
|
static void bdrv_replace_child_abort(void *opaque)
|
|
{
|
|
BdrvReplaceChildState *s = opaque;
|
|
BlockDriverState *new_bs = s->child->bs;
|
|
|
|
/* old_bs reference is transparently moved from @s to @s->child */
|
|
bdrv_replace_child_noperm(s->child, s->old_bs);
|
|
bdrv_unref(new_bs);
|
|
}
|
|
|
|
static TransactionActionDrv bdrv_replace_child_drv = {
|
|
.commit = bdrv_replace_child_commit,
|
|
.abort = bdrv_replace_child_abort,
|
|
.clean = g_free,
|
|
};
|
|
|
|
/*
|
|
* bdrv_replace_child
|
|
*
|
|
* Note: real unref of old_bs is done only on commit.
|
|
*/
|
|
static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs,
|
|
Transaction *tran)
|
|
{
|
|
BdrvReplaceChildState *s = g_new(BdrvReplaceChildState, 1);
|
|
*s = (BdrvReplaceChildState) {
|
|
.child = child,
|
|
.old_bs = child->bs,
|
|
};
|
|
tran_add(tran, &bdrv_replace_child_drv, s);
|
|
|
|
if (new_bs) {
|
|
bdrv_ref(new_bs);
|
|
}
|
|
bdrv_replace_child_noperm(child, new_bs);
|
|
/* old_bs reference is transparently moved from @child to @s */
|
|
}
|
|
|
|
/*
|
|
* Refresh permissions in @bs subtree. The function is intended to be called
|
|
* after some graph modification that was done without permission update.
|
|
*/
|
|
static int bdrv_node_refresh_perm(BlockDriverState *bs, BlockReopenQueue *q,
|
|
Transaction *tran, Error **errp)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
BdrvChild *c;
|
|
int ret;
|
|
uint64_t cumulative_perms, cumulative_shared_perms;
|
|
|
|
bdrv_get_cumulative_perm(bs, &cumulative_perms, &cumulative_shared_perms);
|
|
|
|
/* Write permissions never work with read-only images */
|
|
if ((cumulative_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) &&
|
|
!bdrv_is_writable_after_reopen(bs, q))
|
|
{
|
|
if (!bdrv_is_writable_after_reopen(bs, NULL)) {
|
|
error_setg(errp, "Block node is read-only");
|
|
} else {
|
|
error_setg(errp, "Read-only block node '%s' cannot support "
|
|
"read-write users", bdrv_get_node_name(bs));
|
|
}
|
|
|
|
return -EPERM;
|
|
}
|
|
|
|
/*
|
|
* Unaligned requests will automatically be aligned to bl.request_alignment
|
|
* and without RESIZE we can't extend requests to write to space beyond the
|
|
* end of the image, so it's required that the image size is aligned.
|
|
*/
|
|
if ((cumulative_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) &&
|
|
!(cumulative_perms & BLK_PERM_RESIZE))
|
|
{
|
|
if ((bs->total_sectors * BDRV_SECTOR_SIZE) % bs->bl.request_alignment) {
|
|
error_setg(errp, "Cannot get 'write' permission without 'resize': "
|
|
"Image size is not a multiple of request "
|
|
"alignment");
|
|
return -EPERM;
|
|
}
|
|
}
|
|
|
|
/* Check this node */
|
|
if (!drv) {
|
|
return 0;
|
|
}
|
|
|
|
ret = bdrv_drv_set_perm(bs, cumulative_perms, cumulative_shared_perms, tran,
|
|
errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
/* Drivers that never have children can omit .bdrv_child_perm() */
|
|
if (!drv->bdrv_child_perm) {
|
|
assert(QLIST_EMPTY(&bs->children));
|
|
return 0;
|
|
}
|
|
|
|
/* Check all children */
|
|
QLIST_FOREACH(c, &bs->children, next) {
|
|
uint64_t cur_perm, cur_shared;
|
|
|
|
bdrv_child_perm(bs, c->bs, c, c->role, q,
|
|
cumulative_perms, cumulative_shared_perms,
|
|
&cur_perm, &cur_shared);
|
|
bdrv_child_set_perm(c, cur_perm, cur_shared, tran);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bdrv_list_refresh_perms(GSList *list, BlockReopenQueue *q,
|
|
Transaction *tran, Error **errp)
|
|
{
|
|
int ret;
|
|
BlockDriverState *bs;
|
|
|
|
for ( ; list; list = list->next) {
|
|
bs = list->data;
|
|
|
|
if (bdrv_parent_perms_conflict(bs, errp)) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
ret = bdrv_node_refresh_perm(bs, q, tran, errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm,
|
|
uint64_t *shared_perm)
|
|
{
|
|
BdrvChild *c;
|
|
uint64_t cumulative_perms = 0;
|
|
uint64_t cumulative_shared_perms = BLK_PERM_ALL;
|
|
|
|
QLIST_FOREACH(c, &bs->parents, next_parent) {
|
|
cumulative_perms |= c->perm;
|
|
cumulative_shared_perms &= c->shared_perm;
|
|
}
|
|
|
|
*perm = cumulative_perms;
|
|
*shared_perm = cumulative_shared_perms;
|
|
}
|
|
|
|
char *bdrv_perm_names(uint64_t perm)
|
|
{
|
|
struct perm_name {
|
|
uint64_t perm;
|
|
const char *name;
|
|
} permissions[] = {
|
|
{ BLK_PERM_CONSISTENT_READ, "consistent read" },
|
|
{ BLK_PERM_WRITE, "write" },
|
|
{ BLK_PERM_WRITE_UNCHANGED, "write unchanged" },
|
|
{ BLK_PERM_RESIZE, "resize" },
|
|
{ BLK_PERM_GRAPH_MOD, "change children" },
|
|
{ 0, NULL }
|
|
};
|
|
|
|
GString *result = g_string_sized_new(30);
|
|
struct perm_name *p;
|
|
|
|
for (p = permissions; p->name; p++) {
|
|
if (perm & p->perm) {
|
|
if (result->len > 0) {
|
|
g_string_append(result, ", ");
|
|
}
|
|
g_string_append(result, p->name);
|
|
}
|
|
}
|
|
|
|
return g_string_free(result, FALSE);
|
|
}
|
|
|
|
|
|
static int bdrv_refresh_perms(BlockDriverState *bs, Error **errp)
|
|
{
|
|
int ret;
|
|
Transaction *tran = tran_new();
|
|
g_autoptr(GSList) list = bdrv_topological_dfs(NULL, NULL, bs);
|
|
|
|
ret = bdrv_list_refresh_perms(list, NULL, tran, errp);
|
|
tran_finalize(tran, ret);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
|
|
Error **errp)
|
|
{
|
|
Error *local_err = NULL;
|
|
Transaction *tran = tran_new();
|
|
int ret;
|
|
|
|
bdrv_child_set_perm(c, perm, shared, tran);
|
|
|
|
ret = bdrv_refresh_perms(c->bs, &local_err);
|
|
|
|
tran_finalize(tran, ret);
|
|
|
|
if (ret < 0) {
|
|
if ((perm & ~c->perm) || (c->shared_perm & ~shared)) {
|
|
/* tighten permissions */
|
|
error_propagate(errp, local_err);
|
|
} else {
|
|
/*
|
|
* Our caller may intend to only loosen restrictions and
|
|
* does not expect this function to fail. Errors are not
|
|
* fatal in such a case, so we can just hide them from our
|
|
* caller.
|
|
*/
|
|
error_free(local_err);
|
|
ret = 0;
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
int bdrv_child_refresh_perms(BlockDriverState *bs, BdrvChild *c, Error **errp)
|
|
{
|
|
uint64_t parent_perms, parent_shared;
|
|
uint64_t perms, shared;
|
|
|
|
bdrv_get_cumulative_perm(bs, &parent_perms, &parent_shared);
|
|
bdrv_child_perm(bs, c->bs, c, c->role, NULL,
|
|
parent_perms, parent_shared, &perms, &shared);
|
|
|
|
return bdrv_child_try_set_perm(c, perms, shared, errp);
|
|
}
|
|
|
|
/*
|
|
* Default implementation for .bdrv_child_perm() for block filters:
|
|
* Forward CONSISTENT_READ, WRITE, WRITE_UNCHANGED, and RESIZE to the
|
|
* filtered child.
|
|
*/
|
|
static void bdrv_filter_default_perms(BlockDriverState *bs, BdrvChild *c,
|
|
BdrvChildRole role,
|
|
BlockReopenQueue *reopen_queue,
|
|
uint64_t perm, uint64_t shared,
|
|
uint64_t *nperm, uint64_t *nshared)
|
|
{
|
|
*nperm = perm & DEFAULT_PERM_PASSTHROUGH;
|
|
*nshared = (shared & DEFAULT_PERM_PASSTHROUGH) | DEFAULT_PERM_UNCHANGED;
|
|
}
|
|
|
|
static void bdrv_default_perms_for_cow(BlockDriverState *bs, BdrvChild *c,
|
|
BdrvChildRole role,
|
|
BlockReopenQueue *reopen_queue,
|
|
uint64_t perm, uint64_t shared,
|
|
uint64_t *nperm, uint64_t *nshared)
|
|
{
|
|
assert(role & BDRV_CHILD_COW);
|
|
|
|
/*
|
|
* We want consistent read from backing files if the parent needs it.
|
|
* No other operations are performed on backing files.
|
|
*/
|
|
perm &= BLK_PERM_CONSISTENT_READ;
|
|
|
|
/*
|
|
* If the parent can deal with changing data, we're okay with a
|
|
* writable and resizable backing file.
|
|
* TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too?
|
|
*/
|
|
if (shared & BLK_PERM_WRITE) {
|
|
shared = BLK_PERM_WRITE | BLK_PERM_RESIZE;
|
|
} else {
|
|
shared = 0;
|
|
}
|
|
|
|
shared |= BLK_PERM_CONSISTENT_READ | BLK_PERM_GRAPH_MOD |
|
|
BLK_PERM_WRITE_UNCHANGED;
|
|
|
|
if (bs->open_flags & BDRV_O_INACTIVE) {
|
|
shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE;
|
|
}
|
|
|
|
*nperm = perm;
|
|
*nshared = shared;
|
|
}
|
|
|
|
static void bdrv_default_perms_for_storage(BlockDriverState *bs, BdrvChild *c,
|
|
BdrvChildRole role,
|
|
BlockReopenQueue *reopen_queue,
|
|
uint64_t perm, uint64_t shared,
|
|
uint64_t *nperm, uint64_t *nshared)
|
|
{
|
|
int flags;
|
|
|
|
assert(role & (BDRV_CHILD_METADATA | BDRV_CHILD_DATA));
|
|
|
|
flags = bdrv_reopen_get_flags(reopen_queue, bs);
|
|
|
|
/*
|
|
* Apart from the modifications below, the same permissions are
|
|
* forwarded and left alone as for filters
|
|
*/
|
|
bdrv_filter_default_perms(bs, c, role, reopen_queue,
|
|
perm, shared, &perm, &shared);
|
|
|
|
if (role & BDRV_CHILD_METADATA) {
|
|
/* Format drivers may touch metadata even if the guest doesn't write */
|
|
if (bdrv_is_writable_after_reopen(bs, reopen_queue)) {
|
|
perm |= BLK_PERM_WRITE | BLK_PERM_RESIZE;
|
|
}
|
|
|
|
/*
|
|
* bs->file always needs to be consistent because of the
|
|
* metadata. We can never allow other users to resize or write
|
|
* to it.
|
|
*/
|
|
if (!(flags & BDRV_O_NO_IO)) {
|
|
perm |= BLK_PERM_CONSISTENT_READ;
|
|
}
|
|
shared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE);
|
|
}
|
|
|
|
if (role & BDRV_CHILD_DATA) {
|
|
/*
|
|
* Technically, everything in this block is a subset of the
|
|
* BDRV_CHILD_METADATA path taken above, and so this could
|
|
* be an "else if" branch. However, that is not obvious, and
|
|
* this function is not performance critical, therefore we let
|
|
* this be an independent "if".
|
|
*/
|
|
|
|
/*
|
|
* We cannot allow other users to resize the file because the
|
|
* format driver might have some assumptions about the size
|
|
* (e.g. because it is stored in metadata, or because the file
|
|
* is split into fixed-size data files).
|
|
*/
|
|
shared &= ~BLK_PERM_RESIZE;
|
|
|
|
/*
|
|
* WRITE_UNCHANGED often cannot be performed as such on the
|
|
* data file. For example, the qcow2 driver may still need to
|
|
* write copied clusters on copy-on-read.
|
|
*/
|
|
if (perm & BLK_PERM_WRITE_UNCHANGED) {
|
|
perm |= BLK_PERM_WRITE;
|
|
}
|
|
|
|
/*
|
|
* If the data file is written to, the format driver may
|
|
* expect to be able to resize it by writing beyond the EOF.
|
|
*/
|
|
if (perm & BLK_PERM_WRITE) {
|
|
perm |= BLK_PERM_RESIZE;
|
|
}
|
|
}
|
|
|
|
if (bs->open_flags & BDRV_O_INACTIVE) {
|
|
shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE;
|
|
}
|
|
|
|
*nperm = perm;
|
|
*nshared = shared;
|
|
}
|
|
|
|
void bdrv_default_perms(BlockDriverState *bs, BdrvChild *c,
|
|
BdrvChildRole role, BlockReopenQueue *reopen_queue,
|
|
uint64_t perm, uint64_t shared,
|
|
uint64_t *nperm, uint64_t *nshared)
|
|
{
|
|
if (role & BDRV_CHILD_FILTERED) {
|
|
assert(!(role & (BDRV_CHILD_DATA | BDRV_CHILD_METADATA |
|
|
BDRV_CHILD_COW)));
|
|
bdrv_filter_default_perms(bs, c, role, reopen_queue,
|
|
perm, shared, nperm, nshared);
|
|
} else if (role & BDRV_CHILD_COW) {
|
|
assert(!(role & (BDRV_CHILD_DATA | BDRV_CHILD_METADATA)));
|
|
bdrv_default_perms_for_cow(bs, c, role, reopen_queue,
|
|
perm, shared, nperm, nshared);
|
|
} else if (role & (BDRV_CHILD_METADATA | BDRV_CHILD_DATA)) {
|
|
bdrv_default_perms_for_storage(bs, c, role, reopen_queue,
|
|
perm, shared, nperm, nshared);
|
|
} else {
|
|
g_assert_not_reached();
|
|
}
|
|
}
|
|
|
|
uint64_t bdrv_qapi_perm_to_blk_perm(BlockPermission qapi_perm)
|
|
{
|
|
static const uint64_t permissions[] = {
|
|
[BLOCK_PERMISSION_CONSISTENT_READ] = BLK_PERM_CONSISTENT_READ,
|
|
[BLOCK_PERMISSION_WRITE] = BLK_PERM_WRITE,
|
|
[BLOCK_PERMISSION_WRITE_UNCHANGED] = BLK_PERM_WRITE_UNCHANGED,
|
|
[BLOCK_PERMISSION_RESIZE] = BLK_PERM_RESIZE,
|
|
[BLOCK_PERMISSION_GRAPH_MOD] = BLK_PERM_GRAPH_MOD,
|
|
};
|
|
|
|
QEMU_BUILD_BUG_ON(ARRAY_SIZE(permissions) != BLOCK_PERMISSION__MAX);
|
|
QEMU_BUILD_BUG_ON(1UL << ARRAY_SIZE(permissions) != BLK_PERM_ALL + 1);
|
|
|
|
assert(qapi_perm < BLOCK_PERMISSION__MAX);
|
|
|
|
return permissions[qapi_perm];
|
|
}
|
|
|
|
static void bdrv_replace_child_noperm(BdrvChild *child,
|
|
BlockDriverState *new_bs)
|
|
{
|
|
BlockDriverState *old_bs = child->bs;
|
|
int new_bs_quiesce_counter;
|
|
int drain_saldo;
|
|
|
|
assert(!child->frozen);
|
|
|
|
if (old_bs && new_bs) {
|
|
assert(bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs));
|
|
}
|
|
|
|
new_bs_quiesce_counter = (new_bs ? new_bs->quiesce_counter : 0);
|
|
drain_saldo = new_bs_quiesce_counter - child->parent_quiesce_counter;
|
|
|
|
/*
|
|
* If the new child node is drained but the old one was not, flush
|
|
* all outstanding requests to the old child node.
|
|
*/
|
|
while (drain_saldo > 0 && child->klass->drained_begin) {
|
|
bdrv_parent_drained_begin_single(child, true);
|
|
drain_saldo--;
|
|
}
|
|
|
|
if (old_bs) {
|
|
/* Detach first so that the recursive drain sections coming from @child
|
|
* are already gone and we only end the drain sections that came from
|
|
* elsewhere. */
|
|
if (child->klass->detach) {
|
|
child->klass->detach(child);
|
|
}
|
|
QLIST_REMOVE(child, next_parent);
|
|
}
|
|
|
|
child->bs = new_bs;
|
|
|
|
if (new_bs) {
|
|
QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent);
|
|
|
|
/*
|
|
* Detaching the old node may have led to the new node's
|
|
* quiesce_counter having been decreased. Not a problem, we
|
|
* just need to recognize this here and then invoke
|
|
* drained_end appropriately more often.
|
|
*/
|
|
assert(new_bs->quiesce_counter <= new_bs_quiesce_counter);
|
|
drain_saldo += new_bs->quiesce_counter - new_bs_quiesce_counter;
|
|
|
|
/* Attach only after starting new drained sections, so that recursive
|
|
* drain sections coming from @child don't get an extra .drained_begin
|
|
* callback. */
|
|
if (child->klass->attach) {
|
|
child->klass->attach(child);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If the old child node was drained but the new one is not, allow
|
|
* requests to come in only after the new node has been attached.
|
|
*/
|
|
while (drain_saldo < 0 && child->klass->drained_end) {
|
|
bdrv_parent_drained_end_single(child);
|
|
drain_saldo++;
|
|
}
|
|
}
|
|
|
|
static void bdrv_child_free(void *opaque)
|
|
{
|
|
BdrvChild *c = opaque;
|
|
|
|
g_free(c->name);
|
|
g_free(c);
|
|
}
|
|
|
|
static void bdrv_remove_empty_child(BdrvChild *child)
|
|
{
|
|
assert(!child->bs);
|
|
QLIST_SAFE_REMOVE(child, next);
|
|
bdrv_child_free(child);
|
|
}
|
|
|
|
typedef struct BdrvAttachChildCommonState {
|
|
BdrvChild **child;
|
|
AioContext *old_parent_ctx;
|
|
AioContext *old_child_ctx;
|
|
} BdrvAttachChildCommonState;
|
|
|
|
static void bdrv_attach_child_common_abort(void *opaque)
|
|
{
|
|
BdrvAttachChildCommonState *s = opaque;
|
|
BdrvChild *child = *s->child;
|
|
BlockDriverState *bs = child->bs;
|
|
|
|
bdrv_replace_child_noperm(child, NULL);
|
|
|
|
if (bdrv_get_aio_context(bs) != s->old_child_ctx) {
|
|
bdrv_try_set_aio_context(bs, s->old_child_ctx, &error_abort);
|
|
}
|
|
|
|
if (bdrv_child_get_parent_aio_context(child) != s->old_parent_ctx) {
|
|
GSList *ignore = g_slist_prepend(NULL, child);
|
|
|
|
child->klass->can_set_aio_ctx(child, s->old_parent_ctx, &ignore,
|
|
&error_abort);
|
|
g_slist_free(ignore);
|
|
ignore = g_slist_prepend(NULL, child);
|
|
child->klass->set_aio_ctx(child, s->old_parent_ctx, &ignore);
|
|
|
|
g_slist_free(ignore);
|
|
}
|
|
|
|
bdrv_unref(bs);
|
|
bdrv_remove_empty_child(child);
|
|
*s->child = NULL;
|
|
}
|
|
|
|
static TransactionActionDrv bdrv_attach_child_common_drv = {
|
|
.abort = bdrv_attach_child_common_abort,
|
|
.clean = g_free,
|
|
};
|
|
|
|
/*
|
|
* Common part of attaching bdrv child to bs or to blk or to job
|
|
*
|
|
* Resulting new child is returned through @child.
|
|
* At start *@child must be NULL.
|
|
* @child is saved to a new entry of @tran, so that *@child could be reverted to
|
|
* NULL on abort(). So referenced variable must live at least until transaction
|
|
* end.
|
|
*/
|
|
static int bdrv_attach_child_common(BlockDriverState *child_bs,
|
|
const char *child_name,
|
|
const BdrvChildClass *child_class,
|
|
BdrvChildRole child_role,
|
|
uint64_t perm, uint64_t shared_perm,
|
|
void *opaque, BdrvChild **child,
|
|
Transaction *tran, Error **errp)
|
|
{
|
|
BdrvChild *new_child;
|
|
AioContext *parent_ctx;
|
|
AioContext *child_ctx = bdrv_get_aio_context(child_bs);
|
|
|
|
assert(child);
|
|
assert(*child == NULL);
|
|
assert(child_class->get_parent_desc);
|
|
|
|
new_child = g_new(BdrvChild, 1);
|
|
*new_child = (BdrvChild) {
|
|
.bs = NULL,
|
|
.name = g_strdup(child_name),
|
|
.klass = child_class,
|
|
.role = child_role,
|
|
.perm = perm,
|
|
.shared_perm = shared_perm,
|
|
.opaque = opaque,
|
|
};
|
|
|
|
/*
|
|
* If the AioContexts don't match, first try to move the subtree of
|
|
* child_bs into the AioContext of the new parent. If this doesn't work,
|
|
* try moving the parent into the AioContext of child_bs instead.
|
|
*/
|
|
parent_ctx = bdrv_child_get_parent_aio_context(new_child);
|
|
if (child_ctx != parent_ctx) {
|
|
Error *local_err = NULL;
|
|
int ret = bdrv_try_set_aio_context(child_bs, parent_ctx, &local_err);
|
|
|
|
if (ret < 0 && child_class->can_set_aio_ctx) {
|
|
GSList *ignore = g_slist_prepend(NULL, new_child);
|
|
if (child_class->can_set_aio_ctx(new_child, child_ctx, &ignore,
|
|
NULL))
|
|
{
|
|
error_free(local_err);
|
|
ret = 0;
|
|
g_slist_free(ignore);
|
|
ignore = g_slist_prepend(NULL, new_child);
|
|
child_class->set_aio_ctx(new_child, child_ctx, &ignore);
|
|
}
|
|
g_slist_free(ignore);
|
|
}
|
|
|
|
if (ret < 0) {
|
|
error_propagate(errp, local_err);
|
|
bdrv_remove_empty_child(new_child);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
bdrv_ref(child_bs);
|
|
bdrv_replace_child_noperm(new_child, child_bs);
|
|
|
|
*child = new_child;
|
|
|
|
BdrvAttachChildCommonState *s = g_new(BdrvAttachChildCommonState, 1);
|
|
*s = (BdrvAttachChildCommonState) {
|
|
.child = child,
|
|
.old_parent_ctx = parent_ctx,
|
|
.old_child_ctx = child_ctx,
|
|
};
|
|
tran_add(tran, &bdrv_attach_child_common_drv, s);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Variable referenced by @child must live at least until transaction end.
|
|
* (see bdrv_attach_child_common() doc for details)
|
|
*/
|
|
static int bdrv_attach_child_noperm(BlockDriverState *parent_bs,
|
|
BlockDriverState *child_bs,
|
|
const char *child_name,
|
|
const BdrvChildClass *child_class,
|
|
BdrvChildRole child_role,
|
|
BdrvChild **child,
|
|
Transaction *tran,
|
|
Error **errp)
|
|
{
|
|
int ret;
|
|
uint64_t perm, shared_perm;
|
|
|
|
assert(parent_bs->drv);
|
|
|
|
bdrv_get_cumulative_perm(parent_bs, &perm, &shared_perm);
|
|
bdrv_child_perm(parent_bs, child_bs, NULL, child_role, NULL,
|
|
perm, shared_perm, &perm, &shared_perm);
|
|
|
|
ret = bdrv_attach_child_common(child_bs, child_name, child_class,
|
|
child_role, perm, shared_perm, parent_bs,
|
|
child, tran, errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
QLIST_INSERT_HEAD(&parent_bs->children, *child, next);
|
|
/*
|
|
* child is removed in bdrv_attach_child_common_abort(), so don't care to
|
|
* abort this change separately.
|
|
*/
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void bdrv_detach_child(BdrvChild *child)
|
|
{
|
|
BlockDriverState *old_bs = child->bs;
|
|
|
|
bdrv_replace_child_noperm(child, NULL);
|
|
bdrv_remove_empty_child(child);
|
|
|
|
if (old_bs) {
|
|
/*
|
|
* Update permissions for old node. We're just taking a parent away, so
|
|
* we're loosening restrictions. Errors of permission update are not
|
|
* fatal in this case, ignore them.
|
|
*/
|
|
bdrv_refresh_perms(old_bs, NULL);
|
|
|
|
/*
|
|
* When the parent requiring a non-default AioContext is removed, the
|
|
* node moves back to the main AioContext
|
|
*/
|
|
bdrv_try_set_aio_context(old_bs, qemu_get_aio_context(), NULL);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This function steals the reference to child_bs from the caller.
|
|
* That reference is later dropped by bdrv_root_unref_child().
|
|
*
|
|
* On failure NULL is returned, errp is set and the reference to
|
|
* child_bs is also dropped.
|
|
*
|
|
* The caller must hold the AioContext lock @child_bs, but not that of @ctx
|
|
* (unless @child_bs is already in @ctx).
|
|
*/
|
|
BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
|
|
const char *child_name,
|
|
const BdrvChildClass *child_class,
|
|
BdrvChildRole child_role,
|
|
uint64_t perm, uint64_t shared_perm,
|
|
void *opaque, Error **errp)
|
|
{
|
|
int ret;
|
|
BdrvChild *child = NULL;
|
|
Transaction *tran = tran_new();
|
|
|
|
ret = bdrv_attach_child_common(child_bs, child_name, child_class,
|
|
child_role, perm, shared_perm, opaque,
|
|
&child, tran, errp);
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
|
|
ret = bdrv_refresh_perms(child_bs, errp);
|
|
|
|
out:
|
|
tran_finalize(tran, ret);
|
|
/* child is unset on failure by bdrv_attach_child_common_abort() */
|
|
assert((ret < 0) == !child);
|
|
|
|
bdrv_unref(child_bs);
|
|
return child;
|
|
}
|
|
|
|
/*
|
|
* This function transfers the reference to child_bs from the caller
|
|
* to parent_bs. That reference is later dropped by parent_bs on
|
|
* bdrv_close() or if someone calls bdrv_unref_child().
|
|
*
|
|
* On failure NULL is returned, errp is set and the reference to
|
|
* child_bs is also dropped.
|
|
*
|
|
* If @parent_bs and @child_bs are in different AioContexts, the caller must
|
|
* hold the AioContext lock for @child_bs, but not for @parent_bs.
|
|
*/
|
|
BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
|
|
BlockDriverState *child_bs,
|
|
const char *child_name,
|
|
const BdrvChildClass *child_class,
|
|
BdrvChildRole child_role,
|
|
Error **errp)
|
|
{
|
|
int ret;
|
|
BdrvChild *child = NULL;
|
|
Transaction *tran = tran_new();
|
|
|
|
ret = bdrv_attach_child_noperm(parent_bs, child_bs, child_name, child_class,
|
|
child_role, &child, tran, errp);
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
|
|
ret = bdrv_refresh_perms(parent_bs, errp);
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
|
|
out:
|
|
tran_finalize(tran, ret);
|
|
/* child is unset on failure by bdrv_attach_child_common_abort() */
|
|
assert((ret < 0) == !child);
|
|
|
|
bdrv_unref(child_bs);
|
|
|
|
return child;
|
|
}
|
|
|
|
/* Callers must ensure that child->frozen is false. */
|
|
void bdrv_root_unref_child(BdrvChild *child)
|
|
{
|
|
BlockDriverState *child_bs;
|
|
|
|
child_bs = child->bs;
|
|
bdrv_detach_child(child);
|
|
bdrv_unref(child_bs);
|
|
}
|
|
|
|
typedef struct BdrvSetInheritsFrom {
|
|
BlockDriverState *bs;
|
|
BlockDriverState *old_inherits_from;
|
|
} BdrvSetInheritsFrom;
|
|
|
|
static void bdrv_set_inherits_from_abort(void *opaque)
|
|
{
|
|
BdrvSetInheritsFrom *s = opaque;
|
|
|
|
s->bs->inherits_from = s->old_inherits_from;
|
|
}
|
|
|
|
static TransactionActionDrv bdrv_set_inherits_from_drv = {
|
|
.abort = bdrv_set_inherits_from_abort,
|
|
.clean = g_free,
|
|
};
|
|
|
|
/* @tran is allowed to be NULL. In this case no rollback is possible */
|
|
static void bdrv_set_inherits_from(BlockDriverState *bs,
|
|
BlockDriverState *new_inherits_from,
|
|
Transaction *tran)
|
|
{
|
|
if (tran) {
|
|
BdrvSetInheritsFrom *s = g_new(BdrvSetInheritsFrom, 1);
|
|
|
|
*s = (BdrvSetInheritsFrom) {
|
|
.bs = bs,
|
|
.old_inherits_from = bs->inherits_from,
|
|
};
|
|
|
|
tran_add(tran, &bdrv_set_inherits_from_drv, s);
|
|
}
|
|
|
|
bs->inherits_from = new_inherits_from;
|
|
}
|
|
|
|
/**
|
|
* Clear all inherits_from pointers from children and grandchildren of
|
|
* @root that point to @root, where necessary.
|
|
* @tran is allowed to be NULL. In this case no rollback is possible
|
|
*/
|
|
static void bdrv_unset_inherits_from(BlockDriverState *root, BdrvChild *child,
|
|
Transaction *tran)
|
|
{
|
|
BdrvChild *c;
|
|
|
|
if (child->bs->inherits_from == root) {
|
|
/*
|
|
* Remove inherits_from only when the last reference between root and
|
|
* child->bs goes away.
|
|
*/
|
|
QLIST_FOREACH(c, &root->children, next) {
|
|
if (c != child && c->bs == child->bs) {
|
|
break;
|
|
}
|
|
}
|
|
if (c == NULL) {
|
|
bdrv_set_inherits_from(child->bs, NULL, tran);
|
|
}
|
|
}
|
|
|
|
QLIST_FOREACH(c, &child->bs->children, next) {
|
|
bdrv_unset_inherits_from(root, c, tran);
|
|
}
|
|
}
|
|
|
|
/* Callers must ensure that child->frozen is false. */
|
|
void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child)
|
|
{
|
|
if (child == NULL) {
|
|
return;
|
|
}
|
|
|
|
bdrv_unset_inherits_from(parent, child, NULL);
|
|
bdrv_root_unref_child(child);
|
|
}
|
|
|
|
|
|
static void bdrv_parent_cb_change_media(BlockDriverState *bs, bool load)
|
|
{
|
|
BdrvChild *c;
|
|
QLIST_FOREACH(c, &bs->parents, next_parent) {
|
|
if (c->klass->change_media) {
|
|
c->klass->change_media(c, load);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Return true if you can reach parent going through child->inherits_from
|
|
* recursively. If parent or child are NULL, return false */
|
|
static bool bdrv_inherits_from_recursive(BlockDriverState *child,
|
|
BlockDriverState *parent)
|
|
{
|
|
while (child && child != parent) {
|
|
child = child->inherits_from;
|
|
}
|
|
|
|
return child != NULL;
|
|
}
|
|
|
|
/*
|
|
* Return the BdrvChildRole for @bs's backing child. bs->backing is
|
|
* mostly used for COW backing children (role = COW), but also for
|
|
* filtered children (role = FILTERED | PRIMARY).
|
|
*/
|
|
static BdrvChildRole bdrv_backing_role(BlockDriverState *bs)
|
|
{
|
|
if (bs->drv && bs->drv->is_filter) {
|
|
return BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY;
|
|
} else {
|
|
return BDRV_CHILD_COW;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Sets the bs->backing link of a BDS. A new reference is created; callers
|
|
* which don't need their own reference any more must call bdrv_unref().
|
|
*/
|
|
static int bdrv_set_backing_noperm(BlockDriverState *bs,
|
|
BlockDriverState *backing_hd,
|
|
Transaction *tran, Error **errp)
|
|
{
|
|
int ret = 0;
|
|
bool update_inherits_from = bdrv_chain_contains(bs, backing_hd) &&
|
|
bdrv_inherits_from_recursive(backing_hd, bs);
|
|
|
|
if (bdrv_is_backing_chain_frozen(bs, child_bs(bs->backing), errp)) {
|
|
return -EPERM;
|
|
}
|
|
|
|
if (bs->backing) {
|
|
/* Cannot be frozen, we checked that above */
|
|
bdrv_unset_inherits_from(bs, bs->backing, tran);
|
|
bdrv_remove_filter_or_cow_child(bs, tran);
|
|
}
|
|
|
|
if (!backing_hd) {
|
|
goto out;
|
|
}
|
|
|
|
ret = bdrv_attach_child_noperm(bs, backing_hd, "backing",
|
|
&child_of_bds, bdrv_backing_role(bs),
|
|
&bs->backing, tran, errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
|
|
/*
|
|
* If backing_hd was already part of bs's backing chain, and
|
|
* inherits_from pointed recursively to bs then let's update it to
|
|
* point directly to bs (else it will become NULL).
|
|
*/
|
|
if (update_inherits_from) {
|
|
bdrv_set_inherits_from(backing_hd, bs, tran);
|
|
}
|
|
|
|
out:
|
|
bdrv_refresh_limits(bs, tran, NULL);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
|
|
Error **errp)
|
|
{
|
|
int ret;
|
|
Transaction *tran = tran_new();
|
|
|
|
ret = bdrv_set_backing_noperm(bs, backing_hd, tran, errp);
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
|
|
ret = bdrv_refresh_perms(bs, errp);
|
|
out:
|
|
tran_finalize(tran, ret);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Opens the backing file for a BlockDriverState if not yet open
|
|
*
|
|
* bdref_key specifies the key for the image's BlockdevRef in the options QDict.
|
|
* That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
|
|
* itself, all options starting with "${bdref_key}." are considered part of the
|
|
* BlockdevRef.
|
|
*
|
|
* TODO Can this be unified with bdrv_open_image()?
|
|
*/
|
|
int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
|
|
const char *bdref_key, Error **errp)
|
|
{
|
|
char *backing_filename = NULL;
|
|
char *bdref_key_dot;
|
|
const char *reference = NULL;
|
|
int ret = 0;
|
|
bool implicit_backing = false;
|
|
BlockDriverState *backing_hd;
|
|
QDict *options;
|
|
QDict *tmp_parent_options = NULL;
|
|
Error *local_err = NULL;
|
|
|
|
if (bs->backing != NULL) {
|
|
goto free_exit;
|
|
}
|
|
|
|
/* NULL means an empty set of options */
|
|
if (parent_options == NULL) {
|
|
tmp_parent_options = qdict_new();
|
|
parent_options = tmp_parent_options;
|
|
}
|
|
|
|
bs->open_flags &= ~BDRV_O_NO_BACKING;
|
|
|
|
bdref_key_dot = g_strdup_printf("%s.", bdref_key);
|
|
qdict_extract_subqdict(parent_options, &options, bdref_key_dot);
|
|
g_free(bdref_key_dot);
|
|
|
|
/*
|
|
* Caution: while qdict_get_try_str() is fine, getting non-string
|
|
* types would require more care. When @parent_options come from
|
|
* -blockdev or blockdev_add, its members are typed according to
|
|
* the QAPI schema, but when they come from -drive, they're all
|
|
* QString.
|
|
*/
|
|
reference = qdict_get_try_str(parent_options, bdref_key);
|
|
if (reference || qdict_haskey(options, "file.filename")) {
|
|
/* keep backing_filename NULL */
|
|
} else if (bs->backing_file[0] == '\0' && qdict_size(options) == 0) {
|
|
qobject_unref(options);
|
|
goto free_exit;
|
|
} else {
|
|
if (qdict_size(options) == 0) {
|
|
/* If the user specifies options that do not modify the
|
|
* backing file's behavior, we might still consider it the
|
|
* implicit backing file. But it's easier this way, and
|
|
* just specifying some of the backing BDS's options is
|
|
* only possible with -drive anyway (otherwise the QAPI
|
|
* schema forces the user to specify everything). */
|
|
implicit_backing = !strcmp(bs->auto_backing_file, bs->backing_file);
|
|
}
|
|
|
|
backing_filename = bdrv_get_full_backing_filename(bs, &local_err);
|
|
if (local_err) {
|
|
ret = -EINVAL;
|
|
error_propagate(errp, local_err);
|
|
qobject_unref(options);
|
|
goto free_exit;
|
|
}
|
|
}
|
|
|
|
if (!bs->drv || !bs->drv->supports_backing) {
|
|
ret = -EINVAL;
|
|
error_setg(errp, "Driver doesn't support backing files");
|
|
qobject_unref(options);
|
|
goto free_exit;
|
|
}
|
|
|
|
if (!reference &&
|
|
bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) {
|
|
qdict_put_str(options, "driver", bs->backing_format);
|
|
}
|
|
|
|
backing_hd = bdrv_open_inherit(backing_filename, reference, options, 0, bs,
|
|
&child_of_bds, bdrv_backing_role(bs), errp);
|
|
if (!backing_hd) {
|
|
bs->open_flags |= BDRV_O_NO_BACKING;
|
|
error_prepend(errp, "Could not open backing file: ");
|
|
ret = -EINVAL;
|
|
goto free_exit;
|
|
}
|
|
|
|
if (implicit_backing) {
|
|
bdrv_refresh_filename(backing_hd);
|
|
pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file),
|
|
backing_hd->filename);
|
|
}
|
|
|
|
/* Hook up the backing file link; drop our reference, bs owns the
|
|
* backing_hd reference now */
|
|
ret = bdrv_set_backing_hd(bs, backing_hd, errp);
|
|
bdrv_unref(backing_hd);
|
|
if (ret < 0) {
|
|
goto free_exit;
|
|
}
|
|
|
|
qdict_del(parent_options, bdref_key);
|
|
|
|
free_exit:
|
|
g_free(backing_filename);
|
|
qobject_unref(tmp_parent_options);
|
|
return ret;
|
|
}
|
|
|
|
static BlockDriverState *
|
|
bdrv_open_child_bs(const char *filename, QDict *options, const char *bdref_key,
|
|
BlockDriverState *parent, const BdrvChildClass *child_class,
|
|
BdrvChildRole child_role, bool allow_none, Error **errp)
|
|
{
|
|
BlockDriverState *bs = NULL;
|
|
QDict *image_options;
|
|
char *bdref_key_dot;
|
|
const char *reference;
|
|
|
|
assert(child_class != NULL);
|
|
|
|
bdref_key_dot = g_strdup_printf("%s.", bdref_key);
|
|
qdict_extract_subqdict(options, &image_options, bdref_key_dot);
|
|
g_free(bdref_key_dot);
|
|
|
|
/*
|
|
* Caution: while qdict_get_try_str() is fine, getting non-string
|
|
* types would require more care. When @options come from
|
|
* -blockdev or blockdev_add, its members are typed according to
|
|
* the QAPI schema, but when they come from -drive, they're all
|
|
* QString.
|
|
*/
|
|
reference = qdict_get_try_str(options, bdref_key);
|
|
if (!filename && !reference && !qdict_size(image_options)) {
|
|
if (!allow_none) {
|
|
error_setg(errp, "A block device must be specified for \"%s\"",
|
|
bdref_key);
|
|
}
|
|
qobject_unref(image_options);
|
|
goto done;
|
|
}
|
|
|
|
bs = bdrv_open_inherit(filename, reference, image_options, 0,
|
|
parent, child_class, child_role, errp);
|
|
if (!bs) {
|
|
goto done;
|
|
}
|
|
|
|
done:
|
|
qdict_del(options, bdref_key);
|
|
return bs;
|
|
}
|
|
|
|
/*
|
|
* Opens a disk image whose options are given as BlockdevRef in another block
|
|
* device's options.
|
|
*
|
|
* If allow_none is true, no image will be opened if filename is false and no
|
|
* BlockdevRef is given. NULL will be returned, but errp remains unset.
|
|
*
|
|
* bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
|
|
* That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
|
|
* itself, all options starting with "${bdref_key}." are considered part of the
|
|
* BlockdevRef.
|
|
*
|
|
* The BlockdevRef will be removed from the options QDict.
|
|
*/
|
|
BdrvChild *bdrv_open_child(const char *filename,
|
|
QDict *options, const char *bdref_key,
|
|
BlockDriverState *parent,
|
|
const BdrvChildClass *child_class,
|
|
BdrvChildRole child_role,
|
|
bool allow_none, Error **errp)
|
|
{
|
|
BlockDriverState *bs;
|
|
|
|
bs = bdrv_open_child_bs(filename, options, bdref_key, parent, child_class,
|
|
child_role, allow_none, errp);
|
|
if (bs == NULL) {
|
|
return NULL;
|
|
}
|
|
|
|
return bdrv_attach_child(parent, bs, bdref_key, child_class, child_role,
|
|
errp);
|
|
}
|
|
|
|
/*
|
|
* TODO Future callers may need to specify parent/child_class in order for
|
|
* option inheritance to work. Existing callers use it for the root node.
|
|
*/
|
|
BlockDriverState *bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp)
|
|
{
|
|
BlockDriverState *bs = NULL;
|
|
QObject *obj = NULL;
|
|
QDict *qdict = NULL;
|
|
const char *reference = NULL;
|
|
Visitor *v = NULL;
|
|
|
|
if (ref->type == QTYPE_QSTRING) {
|
|
reference = ref->u.reference;
|
|
} else {
|
|
BlockdevOptions *options = &ref->u.definition;
|
|
assert(ref->type == QTYPE_QDICT);
|
|
|
|
v = qobject_output_visitor_new(&obj);
|
|
visit_type_BlockdevOptions(v, NULL, &options, &error_abort);
|
|
visit_complete(v, &obj);
|
|
|
|
qdict = qobject_to(QDict, obj);
|
|
qdict_flatten(qdict);
|
|
|
|
/* bdrv_open_inherit() defaults to the values in bdrv_flags (for
|
|
* compatibility with other callers) rather than what we want as the
|
|
* real defaults. Apply the defaults here instead. */
|
|
qdict_set_default_str(qdict, BDRV_OPT_CACHE_DIRECT, "off");
|
|
qdict_set_default_str(qdict, BDRV_OPT_CACHE_NO_FLUSH, "off");
|
|
qdict_set_default_str(qdict, BDRV_OPT_READ_ONLY, "off");
|
|
qdict_set_default_str(qdict, BDRV_OPT_AUTO_READ_ONLY, "off");
|
|
|
|
}
|
|
|
|
bs = bdrv_open_inherit(NULL, reference, qdict, 0, NULL, NULL, 0, errp);
|
|
obj = NULL;
|
|
qobject_unref(obj);
|
|
visit_free(v);
|
|
return bs;
|
|
}
|
|
|
|
static BlockDriverState *bdrv_append_temp_snapshot(BlockDriverState *bs,
|
|
int flags,
|
|
QDict *snapshot_options,
|
|
Error **errp)
|
|
{
|
|
/* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
|
|
char *tmp_filename = g_malloc0(PATH_MAX + 1);
|
|
int64_t total_size;
|
|
QemuOpts *opts = NULL;
|
|
BlockDriverState *bs_snapshot = NULL;
|
|
int ret;
|
|
|
|
/* if snapshot, we create a temporary backing file and open it
|
|
instead of opening 'filename' directly */
|
|
|
|
/* Get the required size from the image */
|
|
total_size = bdrv_getlength(bs);
|
|
if (total_size < 0) {
|
|
error_setg_errno(errp, -total_size, "Could not get image size");
|
|
goto out;
|
|
}
|
|
|
|
/* Create the temporary image */
|
|
ret = get_tmp_filename(tmp_filename, PATH_MAX + 1);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "Could not get temporary filename");
|
|
goto out;
|
|
}
|
|
|
|
opts = qemu_opts_create(bdrv_qcow2.create_opts, NULL, 0,
|
|
&error_abort);
|
|
qemu_opt_set_number(opts, BLOCK_OPT_SIZE, total_size, &error_abort);
|
|
ret = bdrv_create(&bdrv_qcow2, tmp_filename, opts, errp);
|
|
qemu_opts_del(opts);
|
|
if (ret < 0) {
|
|
error_prepend(errp, "Could not create temporary overlay '%s': ",
|
|
tmp_filename);
|
|
goto out;
|
|
}
|
|
|
|
/* Prepare options QDict for the temporary file */
|
|
qdict_put_str(snapshot_options, "file.driver", "file");
|
|
qdict_put_str(snapshot_options, "file.filename", tmp_filename);
|
|
qdict_put_str(snapshot_options, "driver", "qcow2");
|
|
|
|
bs_snapshot = bdrv_open(NULL, NULL, snapshot_options, flags, errp);
|
|
snapshot_options = NULL;
|
|
if (!bs_snapshot) {
|
|
goto out;
|
|
}
|
|
|
|
ret = bdrv_append(bs_snapshot, bs, errp);
|
|
if (ret < 0) {
|
|
bs_snapshot = NULL;
|
|
goto out;
|
|
}
|
|
|
|
out:
|
|
qobject_unref(snapshot_options);
|
|
g_free(tmp_filename);
|
|
return bs_snapshot;
|
|
}
|
|
|
|
/*
|
|
* Opens a disk image (raw, qcow2, vmdk, ...)
|
|
*
|
|
* options is a QDict of options to pass to the block drivers, or NULL for an
|
|
* empty set of options. The reference to the QDict belongs to the block layer
|
|
* after the call (even on failure), so if the caller intends to reuse the
|
|
* dictionary, it needs to use qobject_ref() before calling bdrv_open.
|
|
*
|
|
* If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
|
|
* If it is not NULL, the referenced BDS will be reused.
|
|
*
|
|
* The reference parameter may be used to specify an existing block device which
|
|
* should be opened. If specified, neither options nor a filename may be given,
|
|
* nor can an existing BDS be reused (that is, *pbs has to be NULL).
|
|
*/
|
|
static BlockDriverState *bdrv_open_inherit(const char *filename,
|
|
const char *reference,
|
|
QDict *options, int flags,
|
|
BlockDriverState *parent,
|
|
const BdrvChildClass *child_class,
|
|
BdrvChildRole child_role,
|
|
Error **errp)
|
|
{
|
|
int ret;
|
|
BlockBackend *file = NULL;
|
|
BlockDriverState *bs;
|
|
BlockDriver *drv = NULL;
|
|
BdrvChild *child;
|
|
const char *drvname;
|
|
const char *backing;
|
|
Error *local_err = NULL;
|
|
QDict *snapshot_options = NULL;
|
|
int snapshot_flags = 0;
|
|
|
|
assert(!child_class || !flags);
|
|
assert(!child_class == !parent);
|
|
|
|
if (reference) {
|
|
bool options_non_empty = options ? qdict_size(options) : false;
|
|
qobject_unref(options);
|
|
|
|
if (filename || options_non_empty) {
|
|
error_setg(errp, "Cannot reference an existing block device with "
|
|
"additional options or a new filename");
|
|
return NULL;
|
|
}
|
|
|
|
bs = bdrv_lookup_bs(reference, reference, errp);
|
|
if (!bs) {
|
|
return NULL;
|
|
}
|
|
|
|
bdrv_ref(bs);
|
|
return bs;
|
|
}
|
|
|
|
bs = bdrv_new();
|
|
|
|
/* NULL means an empty set of options */
|
|
if (options == NULL) {
|
|
options = qdict_new();
|
|
}
|
|
|
|
/* json: syntax counts as explicit options, as if in the QDict */
|
|
parse_json_protocol(options, &filename, &local_err);
|
|
if (local_err) {
|
|
goto fail;
|
|
}
|
|
|
|
bs->explicit_options = qdict_clone_shallow(options);
|
|
|
|
if (child_class) {
|
|
bool parent_is_format;
|
|
|
|
if (parent->drv) {
|
|
parent_is_format = parent->drv->is_format;
|
|
} else {
|
|
/*
|
|
* parent->drv is not set yet because this node is opened for
|
|
* (potential) format probing. That means that @parent is going
|
|
* to be a format node.
|
|
*/
|
|
parent_is_format = true;
|
|
}
|
|
|
|
bs->inherits_from = parent;
|
|
child_class->inherit_options(child_role, parent_is_format,
|
|
&flags, options,
|
|
parent->open_flags, parent->options);
|
|
}
|
|
|
|
ret = bdrv_fill_options(&options, filename, &flags, &local_err);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
/*
|
|
* Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags.
|
|
* Caution: getting a boolean member of @options requires care.
|
|
* When @options come from -blockdev or blockdev_add, members are
|
|
* typed according to the QAPI schema, but when they come from
|
|
* -drive, they're all QString.
|
|
*/
|
|
if (g_strcmp0(qdict_get_try_str(options, BDRV_OPT_READ_ONLY), "on") &&
|
|
!qdict_get_try_bool(options, BDRV_OPT_READ_ONLY, false)) {
|
|
flags |= (BDRV_O_RDWR | BDRV_O_ALLOW_RDWR);
|
|
} else {
|
|
flags &= ~BDRV_O_RDWR;
|
|
}
|
|
|
|
if (flags & BDRV_O_SNAPSHOT) {
|
|
snapshot_options = qdict_new();
|
|
bdrv_temp_snapshot_options(&snapshot_flags, snapshot_options,
|
|
flags, options);
|
|
/* Let bdrv_backing_options() override "read-only" */
|
|
qdict_del(options, BDRV_OPT_READ_ONLY);
|
|
bdrv_inherited_options(BDRV_CHILD_COW, true,
|
|
&flags, options, flags, options);
|
|
}
|
|
|
|
bs->open_flags = flags;
|
|
bs->options = options;
|
|
options = qdict_clone_shallow(options);
|
|
|
|
/* Find the right image format driver */
|
|
/* See cautionary note on accessing @options above */
|
|
drvname = qdict_get_try_str(options, "driver");
|
|
if (drvname) {
|
|
drv = bdrv_find_format(drvname);
|
|
if (!drv) {
|
|
error_setg(errp, "Unknown driver: '%s'", drvname);
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
assert(drvname || !(flags & BDRV_O_PROTOCOL));
|
|
|
|
/* See cautionary note on accessing @options above */
|
|
backing = qdict_get_try_str(options, "backing");
|
|
if (qobject_to(QNull, qdict_get(options, "backing")) != NULL ||
|
|
(backing && *backing == '\0'))
|
|
{
|
|
if (backing) {
|
|
warn_report("Use of \"backing\": \"\" is deprecated; "
|
|
"use \"backing\": null instead");
|
|
}
|
|
flags |= BDRV_O_NO_BACKING;
|
|
qdict_del(bs->explicit_options, "backing");
|
|
qdict_del(bs->options, "backing");
|
|
qdict_del(options, "backing");
|
|
}
|
|
|
|
/* Open image file without format layer. This BlockBackend is only used for
|
|
* probing, the block drivers will do their own bdrv_open_child() for the
|
|
* same BDS, which is why we put the node name back into options. */
|
|
if ((flags & BDRV_O_PROTOCOL) == 0) {
|
|
BlockDriverState *file_bs;
|
|
|
|
file_bs = bdrv_open_child_bs(filename, options, "file", bs,
|
|
&child_of_bds, BDRV_CHILD_IMAGE,
|
|
true, &local_err);
|
|
if (local_err) {
|
|
goto fail;
|
|
}
|
|
if (file_bs != NULL) {
|
|
/* Not requesting BLK_PERM_CONSISTENT_READ because we're only
|
|
* looking at the header to guess the image format. This works even
|
|
* in cases where a guest would not see a consistent state. */
|
|
file = blk_new(bdrv_get_aio_context(file_bs), 0, BLK_PERM_ALL);
|
|
blk_insert_bs(file, file_bs, &local_err);
|
|
bdrv_unref(file_bs);
|
|
if (local_err) {
|
|
goto fail;
|
|
}
|
|
|
|
qdict_put_str(options, "file", bdrv_get_node_name(file_bs));
|
|
}
|
|
}
|
|
|
|
/* Image format probing */
|
|
bs->probed = !drv;
|
|
if (!drv && file) {
|
|
ret = find_image_format(file, filename, &drv, &local_err);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
/*
|
|
* This option update would logically belong in bdrv_fill_options(),
|
|
* but we first need to open bs->file for the probing to work, while
|
|
* opening bs->file already requires the (mostly) final set of options
|
|
* so that cache mode etc. can be inherited.
|
|
*
|
|
* Adding the driver later is somewhat ugly, but it's not an option
|
|
* that would ever be inherited, so it's correct. We just need to make
|
|
* sure to update both bs->options (which has the full effective
|
|
* options for bs) and options (which has file.* already removed).
|
|
*/
|
|
qdict_put_str(bs->options, "driver", drv->format_name);
|
|
qdict_put_str(options, "driver", drv->format_name);
|
|
} else if (!drv) {
|
|
error_setg(errp, "Must specify either driver or file");
|
|
goto fail;
|
|
}
|
|
|
|
/* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */
|
|
assert(!!(flags & BDRV_O_PROTOCOL) == !!drv->bdrv_file_open);
|
|
/* file must be NULL if a protocol BDS is about to be created
|
|
* (the inverse results in an error message from bdrv_open_common()) */
|
|
assert(!(flags & BDRV_O_PROTOCOL) || !file);
|
|
|
|
/* Open the image */
|
|
ret = bdrv_open_common(bs, file, options, &local_err);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
if (file) {
|
|
blk_unref(file);
|
|
file = NULL;
|
|
}
|
|
|
|
/* If there is a backing file, use it */
|
|
if ((flags & BDRV_O_NO_BACKING) == 0) {
|
|
ret = bdrv_open_backing_file(bs, options, "backing", &local_err);
|
|
if (ret < 0) {
|
|
goto close_and_fail;
|
|
}
|
|
}
|
|
|
|
/* Remove all children options and references
|
|
* from bs->options and bs->explicit_options */
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
char *child_key_dot;
|
|
child_key_dot = g_strdup_printf("%s.", child->name);
|
|
qdict_extract_subqdict(bs->explicit_options, NULL, child_key_dot);
|
|
qdict_extract_subqdict(bs->options, NULL, child_key_dot);
|
|
qdict_del(bs->explicit_options, child->name);
|
|
qdict_del(bs->options, child->name);
|
|
g_free(child_key_dot);
|
|
}
|
|
|
|
/* Check if any unknown options were used */
|
|
if (qdict_size(options) != 0) {
|
|
const QDictEntry *entry = qdict_first(options);
|
|
if (flags & BDRV_O_PROTOCOL) {
|
|
error_setg(errp, "Block protocol '%s' doesn't support the option "
|
|
"'%s'", drv->format_name, entry->key);
|
|
} else {
|
|
error_setg(errp,
|
|
"Block format '%s' does not support the option '%s'",
|
|
drv->format_name, entry->key);
|
|
}
|
|
|
|
goto close_and_fail;
|
|
}
|
|
|
|
bdrv_parent_cb_change_media(bs, true);
|
|
|
|
qobject_unref(options);
|
|
options = NULL;
|
|
|
|
/* For snapshot=on, create a temporary qcow2 overlay. bs points to the
|
|
* temporary snapshot afterwards. */
|
|
if (snapshot_flags) {
|
|
BlockDriverState *snapshot_bs;
|
|
snapshot_bs = bdrv_append_temp_snapshot(bs, snapshot_flags,
|
|
snapshot_options, &local_err);
|
|
snapshot_options = NULL;
|
|
if (local_err) {
|
|
goto close_and_fail;
|
|
}
|
|
/* We are not going to return bs but the overlay on top of it
|
|
* (snapshot_bs); thus, we have to drop the strong reference to bs
|
|
* (which we obtained by calling bdrv_new()). bs will not be deleted,
|
|
* though, because the overlay still has a reference to it. */
|
|
bdrv_unref(bs);
|
|
bs = snapshot_bs;
|
|
}
|
|
|
|
return bs;
|
|
|
|
fail:
|
|
blk_unref(file);
|
|
qobject_unref(snapshot_options);
|
|
qobject_unref(bs->explicit_options);
|
|
qobject_unref(bs->options);
|
|
qobject_unref(options);
|
|
bs->options = NULL;
|
|
bs->explicit_options = NULL;
|
|
bdrv_unref(bs);
|
|
error_propagate(errp, local_err);
|
|
return NULL;
|
|
|
|
close_and_fail:
|
|
bdrv_unref(bs);
|
|
qobject_unref(snapshot_options);
|
|
qobject_unref(options);
|
|
error_propagate(errp, local_err);
|
|
return NULL;
|
|
}
|
|
|
|
BlockDriverState *bdrv_open(const char *filename, const char *reference,
|
|
QDict *options, int flags, Error **errp)
|
|
{
|
|
return bdrv_open_inherit(filename, reference, options, flags, NULL,
|
|
NULL, 0, errp);
|
|
}
|
|
|
|
/* Return true if the NULL-terminated @list contains @str */
|
|
static bool is_str_in_list(const char *str, const char *const *list)
|
|
{
|
|
if (str && list) {
|
|
int i;
|
|
for (i = 0; list[i] != NULL; i++) {
|
|
if (!strcmp(str, list[i])) {
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Check that every option set in @bs->options is also set in
|
|
* @new_opts.
|
|
*
|
|
* Options listed in the common_options list and in
|
|
* @bs->drv->mutable_opts are skipped.
|
|
*
|
|
* Return 0 on success, otherwise return -EINVAL and set @errp.
|
|
*/
|
|
static int bdrv_reset_options_allowed(BlockDriverState *bs,
|
|
const QDict *new_opts, Error **errp)
|
|
{
|
|
const QDictEntry *e;
|
|
/* These options are common to all block drivers and are handled
|
|
* in bdrv_reopen_prepare() so they can be left out of @new_opts */
|
|
const char *const common_options[] = {
|
|
"node-name", "discard", "cache.direct", "cache.no-flush",
|
|
"read-only", "auto-read-only", "detect-zeroes", NULL
|
|
};
|
|
|
|
for (e = qdict_first(bs->options); e; e = qdict_next(bs->options, e)) {
|
|
if (!qdict_haskey(new_opts, e->key) &&
|
|
!is_str_in_list(e->key, common_options) &&
|
|
!is_str_in_list(e->key, bs->drv->mutable_opts)) {
|
|
error_setg(errp, "Option '%s' cannot be reset "
|
|
"to its default value", e->key);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Returns true if @child can be reached recursively from @bs
|
|
*/
|
|
static bool bdrv_recurse_has_child(BlockDriverState *bs,
|
|
BlockDriverState *child)
|
|
{
|
|
BdrvChild *c;
|
|
|
|
if (bs == child) {
|
|
return true;
|
|
}
|
|
|
|
QLIST_FOREACH(c, &bs->children, next) {
|
|
if (bdrv_recurse_has_child(c->bs, child)) {
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Adds a BlockDriverState to a simple queue for an atomic, transactional
|
|
* reopen of multiple devices.
|
|
*
|
|
* bs_queue can either be an existing BlockReopenQueue that has had QTAILQ_INIT
|
|
* already performed, or alternatively may be NULL a new BlockReopenQueue will
|
|
* be created and initialized. This newly created BlockReopenQueue should be
|
|
* passed back in for subsequent calls that are intended to be of the same
|
|
* atomic 'set'.
|
|
*
|
|
* bs is the BlockDriverState to add to the reopen queue.
|
|
*
|
|
* options contains the changed options for the associated bs
|
|
* (the BlockReopenQueue takes ownership)
|
|
*
|
|
* flags contains the open flags for the associated bs
|
|
*
|
|
* returns a pointer to bs_queue, which is either the newly allocated
|
|
* bs_queue, or the existing bs_queue being used.
|
|
*
|
|
* bs must be drained between bdrv_reopen_queue() and bdrv_reopen_multiple().
|
|
*/
|
|
static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue,
|
|
BlockDriverState *bs,
|
|
QDict *options,
|
|
const BdrvChildClass *klass,
|
|
BdrvChildRole role,
|
|
bool parent_is_format,
|
|
QDict *parent_options,
|
|
int parent_flags,
|
|
bool keep_old_opts)
|
|
{
|
|
assert(bs != NULL);
|
|
|
|
BlockReopenQueueEntry *bs_entry;
|
|
BdrvChild *child;
|
|
QDict *old_options, *explicit_options, *options_copy;
|
|
int flags;
|
|
QemuOpts *opts;
|
|
|
|
/* Make sure that the caller remembered to use a drained section. This is
|
|
* important to avoid graph changes between the recursive queuing here and
|
|
* bdrv_reopen_multiple(). */
|
|
assert(bs->quiesce_counter > 0);
|
|
|
|
if (bs_queue == NULL) {
|
|
bs_queue = g_new0(BlockReopenQueue, 1);
|
|
QTAILQ_INIT(bs_queue);
|
|
}
|
|
|
|
if (!options) {
|
|
options = qdict_new();
|
|
}
|
|
|
|
/* Check if this BlockDriverState is already in the queue */
|
|
QTAILQ_FOREACH(bs_entry, bs_queue, entry) {
|
|
if (bs == bs_entry->state.bs) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Precedence of options:
|
|
* 1. Explicitly passed in options (highest)
|
|
* 2. Retained from explicitly set options of bs
|
|
* 3. Inherited from parent node
|
|
* 4. Retained from effective options of bs
|
|
*/
|
|
|
|
/* Old explicitly set values (don't overwrite by inherited value) */
|
|
if (bs_entry || keep_old_opts) {
|
|
old_options = qdict_clone_shallow(bs_entry ?
|
|
bs_entry->state.explicit_options :
|
|
bs->explicit_options);
|
|
bdrv_join_options(bs, options, old_options);
|
|
qobject_unref(old_options);
|
|
}
|
|
|
|
explicit_options = qdict_clone_shallow(options);
|
|
|
|
/* Inherit from parent node */
|
|
if (parent_options) {
|
|
flags = 0;
|
|
klass->inherit_options(role, parent_is_format, &flags, options,
|
|
parent_flags, parent_options);
|
|
} else {
|
|
flags = bdrv_get_flags(bs);
|
|
}
|
|
|
|
if (keep_old_opts) {
|
|
/* Old values are used for options that aren't set yet */
|
|
old_options = qdict_clone_shallow(bs->options);
|
|
bdrv_join_options(bs, options, old_options);
|
|
qobject_unref(old_options);
|
|
}
|
|
|
|
/* We have the final set of options so let's update the flags */
|
|
options_copy = qdict_clone_shallow(options);
|
|
opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort);
|
|
qemu_opts_absorb_qdict(opts, options_copy, NULL);
|
|
update_flags_from_options(&flags, opts);
|
|
qemu_opts_del(opts);
|
|
qobject_unref(options_copy);
|
|
|
|
/* bdrv_open_inherit() sets and clears some additional flags internally */
|
|
flags &= ~BDRV_O_PROTOCOL;
|
|
if (flags & BDRV_O_RDWR) {
|
|
flags |= BDRV_O_ALLOW_RDWR;
|
|
}
|
|
|
|
if (!bs_entry) {
|
|
bs_entry = g_new0(BlockReopenQueueEntry, 1);
|
|
QTAILQ_INSERT_TAIL(bs_queue, bs_entry, entry);
|
|
} else {
|
|
qobject_unref(bs_entry->state.options);
|
|
qobject_unref(bs_entry->state.explicit_options);
|
|
}
|
|
|
|
bs_entry->state.bs = bs;
|
|
bs_entry->state.options = options;
|
|
bs_entry->state.explicit_options = explicit_options;
|
|
bs_entry->state.flags = flags;
|
|
|
|
/*
|
|
* If keep_old_opts is false then it means that unspecified
|
|
* options must be reset to their original value. We don't allow
|
|
* resetting 'backing' but we need to know if the option is
|
|
* missing in order to decide if we have to return an error.
|
|
*/
|
|
if (!keep_old_opts) {
|
|
bs_entry->state.backing_missing =
|
|
!qdict_haskey(options, "backing") &&
|
|
!qdict_haskey(options, "backing.driver");
|
|
}
|
|
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
QDict *new_child_options = NULL;
|
|
bool child_keep_old = keep_old_opts;
|
|
|
|
/* reopen can only change the options of block devices that were
|
|
* implicitly created and inherited options. For other (referenced)
|
|
* block devices, a syntax like "backing.foo" results in an error. */
|
|
if (child->bs->inherits_from != bs) {
|
|
continue;
|
|
}
|
|
|
|
/* Check if the options contain a child reference */
|
|
if (qdict_haskey(options, child->name)) {
|
|
const char *childref = qdict_get_try_str(options, child->name);
|
|
/*
|
|
* The current child must not be reopened if the child
|
|
* reference is null or points to a different node.
|
|
*/
|
|
if (g_strcmp0(childref, child->bs->node_name)) {
|
|
continue;
|
|
}
|
|
/*
|
|
* If the child reference points to the current child then
|
|
* reopen it with its existing set of options (note that
|
|
* it can still inherit new options from the parent).
|
|
*/
|
|
child_keep_old = true;
|
|
} else {
|
|
/* Extract child options ("child-name.*") */
|
|
char *child_key_dot = g_strdup_printf("%s.", child->name);
|
|
qdict_extract_subqdict(explicit_options, NULL, child_key_dot);
|
|
qdict_extract_subqdict(options, &new_child_options, child_key_dot);
|
|
g_free(child_key_dot);
|
|
}
|
|
|
|
bdrv_reopen_queue_child(bs_queue, child->bs, new_child_options,
|
|
child->klass, child->role, bs->drv->is_format,
|
|
options, flags, child_keep_old);
|
|
}
|
|
|
|
return bs_queue;
|
|
}
|
|
|
|
BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
|
|
BlockDriverState *bs,
|
|
QDict *options, bool keep_old_opts)
|
|
{
|
|
return bdrv_reopen_queue_child(bs_queue, bs, options, NULL, 0, false,
|
|
NULL, 0, keep_old_opts);
|
|
}
|
|
|
|
/*
|
|
* Reopen multiple BlockDriverStates atomically & transactionally.
|
|
*
|
|
* The queue passed in (bs_queue) must have been built up previous
|
|
* via bdrv_reopen_queue().
|
|
*
|
|
* Reopens all BDS specified in the queue, with the appropriate
|
|
* flags. All devices are prepared for reopen, and failure of any
|
|
* device will cause all device changes to be abandoned, and intermediate
|
|
* data cleaned up.
|
|
*
|
|
* If all devices prepare successfully, then the changes are committed
|
|
* to all devices.
|
|
*
|
|
* All affected nodes must be drained between bdrv_reopen_queue() and
|
|
* bdrv_reopen_multiple().
|
|
*/
|
|
int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp)
|
|
{
|
|
int ret = -1;
|
|
BlockReopenQueueEntry *bs_entry, *next;
|
|
Transaction *tran = tran_new();
|
|
g_autoptr(GHashTable) found = NULL;
|
|
g_autoptr(GSList) refresh_list = NULL;
|
|
|
|
assert(bs_queue != NULL);
|
|
|
|
QTAILQ_FOREACH(bs_entry, bs_queue, entry) {
|
|
ret = bdrv_flush(bs_entry->state.bs);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "Error flushing drive");
|
|
goto abort;
|
|
}
|
|
}
|
|
|
|
QTAILQ_FOREACH(bs_entry, bs_queue, entry) {
|
|
assert(bs_entry->state.bs->quiesce_counter > 0);
|
|
ret = bdrv_reopen_prepare(&bs_entry->state, bs_queue, tran, errp);
|
|
if (ret < 0) {
|
|
goto abort;
|
|
}
|
|
bs_entry->prepared = true;
|
|
}
|
|
|
|
found = g_hash_table_new(NULL, NULL);
|
|
QTAILQ_FOREACH(bs_entry, bs_queue, entry) {
|
|
BDRVReopenState *state = &bs_entry->state;
|
|
|
|
refresh_list = bdrv_topological_dfs(refresh_list, found, state->bs);
|
|
if (state->old_backing_bs) {
|
|
refresh_list = bdrv_topological_dfs(refresh_list, found,
|
|
state->old_backing_bs);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Note that file-posix driver rely on permission update done during reopen
|
|
* (even if no permission changed), because it wants "new" permissions for
|
|
* reconfiguring the fd and that's why it does it in raw_check_perm(), not
|
|
* in raw_reopen_prepare() which is called with "old" permissions.
|
|
*/
|
|
ret = bdrv_list_refresh_perms(refresh_list, bs_queue, tran, errp);
|
|
if (ret < 0) {
|
|
goto abort;
|
|
}
|
|
|
|
/*
|
|
* If we reach this point, we have success and just need to apply the
|
|
* changes.
|
|
*
|
|
* Reverse order is used to comfort qcow2 driver: on commit it need to write
|
|
* IN_USE flag to the image, to mark bitmaps in the image as invalid. But
|
|
* children are usually goes after parents in reopen-queue, so go from last
|
|
* to first element.
|
|
*/
|
|
QTAILQ_FOREACH_REVERSE(bs_entry, bs_queue, entry) {
|
|
bdrv_reopen_commit(&bs_entry->state);
|
|
}
|
|
|
|
tran_commit(tran);
|
|
|
|
QTAILQ_FOREACH_REVERSE(bs_entry, bs_queue, entry) {
|
|
BlockDriverState *bs = bs_entry->state.bs;
|
|
|
|
if (bs->drv->bdrv_reopen_commit_post) {
|
|
bs->drv->bdrv_reopen_commit_post(&bs_entry->state);
|
|
}
|
|
}
|
|
|
|
ret = 0;
|
|
goto cleanup;
|
|
|
|
abort:
|
|
tran_abort(tran);
|
|
QTAILQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) {
|
|
if (bs_entry->prepared) {
|
|
bdrv_reopen_abort(&bs_entry->state);
|
|
}
|
|
qobject_unref(bs_entry->state.explicit_options);
|
|
qobject_unref(bs_entry->state.options);
|
|
}
|
|
|
|
cleanup:
|
|
QTAILQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) {
|
|
g_free(bs_entry);
|
|
}
|
|
g_free(bs_queue);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only,
|
|
Error **errp)
|
|
{
|
|
int ret;
|
|
BlockReopenQueue *queue;
|
|
QDict *opts = qdict_new();
|
|
|
|
qdict_put_bool(opts, BDRV_OPT_READ_ONLY, read_only);
|
|
|
|
bdrv_subtree_drained_begin(bs);
|
|
queue = bdrv_reopen_queue(NULL, bs, opts, true);
|
|
ret = bdrv_reopen_multiple(queue, errp);
|
|
bdrv_subtree_drained_end(bs);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static bool bdrv_reopen_can_attach(BlockDriverState *parent,
|
|
BdrvChild *child,
|
|
BlockDriverState *new_child,
|
|
Error **errp)
|
|
{
|
|
AioContext *parent_ctx = bdrv_get_aio_context(parent);
|
|
AioContext *child_ctx = bdrv_get_aio_context(new_child);
|
|
GSList *ignore;
|
|
bool ret;
|
|
|
|
ignore = g_slist_prepend(NULL, child);
|
|
ret = bdrv_can_set_aio_context(new_child, parent_ctx, &ignore, NULL);
|
|
g_slist_free(ignore);
|
|
if (ret) {
|
|
return ret;
|
|
}
|
|
|
|
ignore = g_slist_prepend(NULL, child);
|
|
ret = bdrv_can_set_aio_context(parent, child_ctx, &ignore, errp);
|
|
g_slist_free(ignore);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Take a BDRVReopenState and check if the value of 'backing' in the
|
|
* reopen_state->options QDict is valid or not.
|
|
*
|
|
* If 'backing' is missing from the QDict then return 0.
|
|
*
|
|
* If 'backing' contains the node name of the backing file of
|
|
* reopen_state->bs then return 0.
|
|
*
|
|
* If 'backing' contains a different node name (or is null) then check
|
|
* whether the current backing file can be replaced with the new one.
|
|
* If that's the case then reopen_state->replace_backing_bs is set to
|
|
* true and reopen_state->new_backing_bs contains a pointer to the new
|
|
* backing BlockDriverState (or NULL).
|
|
*
|
|
* Return 0 on success, otherwise return < 0 and set @errp.
|
|
*/
|
|
static int bdrv_reopen_parse_backing(BDRVReopenState *reopen_state,
|
|
Transaction *set_backings_tran,
|
|
Error **errp)
|
|
{
|
|
BlockDriverState *bs = reopen_state->bs;
|
|
BlockDriverState *overlay_bs, *below_bs, *new_backing_bs;
|
|
QObject *value;
|
|
const char *str;
|
|
|
|
value = qdict_get(reopen_state->options, "backing");
|
|
if (value == NULL) {
|
|
return 0;
|
|
}
|
|
|
|
switch (qobject_type(value)) {
|
|
case QTYPE_QNULL:
|
|
new_backing_bs = NULL;
|
|
break;
|
|
case QTYPE_QSTRING:
|
|
str = qstring_get_str(qobject_to(QString, value));
|
|
new_backing_bs = bdrv_lookup_bs(NULL, str, errp);
|
|
if (new_backing_bs == NULL) {
|
|
return -EINVAL;
|
|
} else if (bdrv_recurse_has_child(new_backing_bs, bs)) {
|
|
error_setg(errp, "Making '%s' a backing file of '%s' "
|
|
"would create a cycle", str, bs->node_name);
|
|
return -EINVAL;
|
|
}
|
|
break;
|
|
default:
|
|
/* 'backing' does not allow any other data type */
|
|
g_assert_not_reached();
|
|
}
|
|
|
|
/*
|
|
* Check AioContext compatibility so that the bdrv_set_backing_hd() call in
|
|
* bdrv_reopen_commit() won't fail.
|
|
*/
|
|
if (new_backing_bs) {
|
|
if (!bdrv_reopen_can_attach(bs, bs->backing, new_backing_bs, errp)) {
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Ensure that @bs can really handle backing files, because we are
|
|
* about to give it one (or swap the existing one)
|
|
*/
|
|
if (bs->drv->is_filter) {
|
|
/* Filters always have a file or a backing child */
|
|
if (!bs->backing) {
|
|
error_setg(errp, "'%s' is a %s filter node that does not support a "
|
|
"backing child", bs->node_name, bs->drv->format_name);
|
|
return -EINVAL;
|
|
}
|
|
} else if (!bs->drv->supports_backing) {
|
|
error_setg(errp, "Driver '%s' of node '%s' does not support backing "
|
|
"files", bs->drv->format_name, bs->node_name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*
|
|
* Find the "actual" backing file by skipping all links that point
|
|
* to an implicit node, if any (e.g. a commit filter node).
|
|
* We cannot use any of the bdrv_skip_*() functions here because
|
|
* those return the first explicit node, while we are looking for
|
|
* its overlay here.
|
|
*/
|
|
overlay_bs = bs;
|
|
for (below_bs = bdrv_filter_or_cow_bs(overlay_bs);
|
|
below_bs && below_bs->implicit;
|
|
below_bs = bdrv_filter_or_cow_bs(overlay_bs))
|
|
{
|
|
overlay_bs = below_bs;
|
|
}
|
|
|
|
/* If we want to replace the backing file we need some extra checks */
|
|
if (new_backing_bs != bdrv_filter_or_cow_bs(overlay_bs)) {
|
|
int ret;
|
|
|
|
/* Check for implicit nodes between bs and its backing file */
|
|
if (bs != overlay_bs) {
|
|
error_setg(errp, "Cannot change backing link if '%s' has "
|
|
"an implicit backing file", bs->node_name);
|
|
return -EPERM;
|
|
}
|
|
/*
|
|
* Check if the backing link that we want to replace is frozen.
|
|
* Note that
|
|
* bdrv_filter_or_cow_child(overlay_bs) == overlay_bs->backing,
|
|
* because we know that overlay_bs == bs, and that @bs
|
|
* either is a filter that uses ->backing or a COW format BDS
|
|
* with bs->drv->supports_backing == true.
|
|
*/
|
|
if (bdrv_is_backing_chain_frozen(overlay_bs,
|
|
child_bs(overlay_bs->backing), errp))
|
|
{
|
|
return -EPERM;
|
|
}
|
|
reopen_state->replace_backing_bs = true;
|
|
reopen_state->old_backing_bs = bs->backing ? bs->backing->bs : NULL;
|
|
ret = bdrv_set_backing_noperm(bs, new_backing_bs, set_backings_tran,
|
|
errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Prepares a BlockDriverState for reopen. All changes are staged in the
|
|
* 'opaque' field of the BDRVReopenState, which is used and allocated by
|
|
* the block driver layer .bdrv_reopen_prepare()
|
|
*
|
|
* bs is the BlockDriverState to reopen
|
|
* flags are the new open flags
|
|
* queue is the reopen queue
|
|
*
|
|
* Returns 0 on success, non-zero on error. On error errp will be set
|
|
* as well.
|
|
*
|
|
* On failure, bdrv_reopen_abort() will be called to clean up any data.
|
|
* It is the responsibility of the caller to then call the abort() or
|
|
* commit() for any other BDS that have been left in a prepare() state
|
|
*
|
|
*/
|
|
static int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
|
|
BlockReopenQueue *queue,
|
|
Transaction *set_backings_tran, Error **errp)
|
|
{
|
|
int ret = -1;
|
|
int old_flags;
|
|
Error *local_err = NULL;
|
|
BlockDriver *drv;
|
|
QemuOpts *opts;
|
|
QDict *orig_reopen_opts;
|
|
char *discard = NULL;
|
|
bool read_only;
|
|
bool drv_prepared = false;
|
|
|
|
assert(reopen_state != NULL);
|
|
assert(reopen_state->bs->drv != NULL);
|
|
drv = reopen_state->bs->drv;
|
|
|
|
/* This function and each driver's bdrv_reopen_prepare() remove
|
|
* entries from reopen_state->options as they are processed, so
|
|
* we need to make a copy of the original QDict. */
|
|
orig_reopen_opts = qdict_clone_shallow(reopen_state->options);
|
|
|
|
/* Process generic block layer options */
|
|
opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort);
|
|
if (!qemu_opts_absorb_qdict(opts, reopen_state->options, errp)) {
|
|
ret = -EINVAL;
|
|
goto error;
|
|
}
|
|
|
|
/* This was already called in bdrv_reopen_queue_child() so the flags
|
|
* are up-to-date. This time we simply want to remove the options from
|
|
* QemuOpts in order to indicate that they have been processed. */
|
|
old_flags = reopen_state->flags;
|
|
update_flags_from_options(&reopen_state->flags, opts);
|
|
assert(old_flags == reopen_state->flags);
|
|
|
|
discard = qemu_opt_get_del(opts, BDRV_OPT_DISCARD);
|
|
if (discard != NULL) {
|
|
if (bdrv_parse_discard_flags(discard, &reopen_state->flags) != 0) {
|
|
error_setg(errp, "Invalid discard option");
|
|
ret = -EINVAL;
|
|
goto error;
|
|
}
|
|
}
|
|
|
|
reopen_state->detect_zeroes =
|
|
bdrv_parse_detect_zeroes(opts, reopen_state->flags, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
ret = -EINVAL;
|
|
goto error;
|
|
}
|
|
|
|
/* All other options (including node-name and driver) must be unchanged.
|
|
* Put them back into the QDict, so that they are checked at the end
|
|
* of this function. */
|
|
qemu_opts_to_qdict(opts, reopen_state->options);
|
|
|
|
/* If we are to stay read-only, do not allow permission change
|
|
* to r/w. Attempting to set to r/w may fail if either BDRV_O_ALLOW_RDWR is
|
|
* not set, or if the BDS still has copy_on_read enabled */
|
|
read_only = !(reopen_state->flags & BDRV_O_RDWR);
|
|
ret = bdrv_can_set_read_only(reopen_state->bs, read_only, true, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
goto error;
|
|
}
|
|
|
|
if (drv->bdrv_reopen_prepare) {
|
|
/*
|
|
* If a driver-specific option is missing, it means that we
|
|
* should reset it to its default value.
|
|
* But not all options allow that, so we need to check it first.
|
|
*/
|
|
ret = bdrv_reset_options_allowed(reopen_state->bs,
|
|
reopen_state->options, errp);
|
|
if (ret) {
|
|
goto error;
|
|
}
|
|
|
|
ret = drv->bdrv_reopen_prepare(reopen_state, queue, &local_err);
|
|
if (ret) {
|
|
if (local_err != NULL) {
|
|
error_propagate(errp, local_err);
|
|
} else {
|
|
bdrv_refresh_filename(reopen_state->bs);
|
|
error_setg(errp, "failed while preparing to reopen image '%s'",
|
|
reopen_state->bs->filename);
|
|
}
|
|
goto error;
|
|
}
|
|
} else {
|
|
/* It is currently mandatory to have a bdrv_reopen_prepare()
|
|
* handler for each supported drv. */
|
|
error_setg(errp, "Block format '%s' used by node '%s' "
|
|
"does not support reopening files", drv->format_name,
|
|
bdrv_get_device_or_node_name(reopen_state->bs));
|
|
ret = -1;
|
|
goto error;
|
|
}
|
|
|
|
drv_prepared = true;
|
|
|
|
/*
|
|
* We must provide the 'backing' option if the BDS has a backing
|
|
* file or if the image file has a backing file name as part of
|
|
* its metadata. Otherwise the 'backing' option can be omitted.
|
|
*/
|
|
if (drv->supports_backing && reopen_state->backing_missing &&
|
|
(reopen_state->bs->backing || reopen_state->bs->backing_file[0])) {
|
|
error_setg(errp, "backing is missing for '%s'",
|
|
reopen_state->bs->node_name);
|
|
ret = -EINVAL;
|
|
goto error;
|
|
}
|
|
|
|
/*
|
|
* Allow changing the 'backing' option. The new value can be
|
|
* either a reference to an existing node (using its node name)
|
|
* or NULL to simply detach the current backing file.
|
|
*/
|
|
ret = bdrv_reopen_parse_backing(reopen_state, set_backings_tran, errp);
|
|
if (ret < 0) {
|
|
goto error;
|
|
}
|
|
qdict_del(reopen_state->options, "backing");
|
|
|
|
/* Options that are not handled are only okay if they are unchanged
|
|
* compared to the old state. It is expected that some options are only
|
|
* used for the initial open, but not reopen (e.g. filename) */
|
|
if (qdict_size(reopen_state->options)) {
|
|
const QDictEntry *entry = qdict_first(reopen_state->options);
|
|
|
|
do {
|
|
QObject *new = entry->value;
|
|
QObject *old = qdict_get(reopen_state->bs->options, entry->key);
|
|
|
|
/* Allow child references (child_name=node_name) as long as they
|
|
* point to the current child (i.e. everything stays the same). */
|
|
if (qobject_type(new) == QTYPE_QSTRING) {
|
|
BdrvChild *child;
|
|
QLIST_FOREACH(child, &reopen_state->bs->children, next) {
|
|
if (!strcmp(child->name, entry->key)) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (child) {
|
|
if (!strcmp(child->bs->node_name,
|
|
qstring_get_str(qobject_to(QString, new)))) {
|
|
continue; /* Found child with this name, skip option */
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* TODO: When using -drive to specify blockdev options, all values
|
|
* will be strings; however, when using -blockdev, blockdev-add or
|
|
* filenames using the json:{} pseudo-protocol, they will be
|
|
* correctly typed.
|
|
* In contrast, reopening options are (currently) always strings
|
|
* (because you can only specify them through qemu-io; all other
|
|
* callers do not specify any options).
|
|
* Therefore, when using anything other than -drive to create a BDS,
|
|
* this cannot detect non-string options as unchanged, because
|
|
* qobject_is_equal() always returns false for objects of different
|
|
* type. In the future, this should be remedied by correctly typing
|
|
* all options. For now, this is not too big of an issue because
|
|
* the user can simply omit options which cannot be changed anyway,
|
|
* so they will stay unchanged.
|
|
*/
|
|
if (!qobject_is_equal(new, old)) {
|
|
error_setg(errp, "Cannot change the option '%s'", entry->key);
|
|
ret = -EINVAL;
|
|
goto error;
|
|
}
|
|
} while ((entry = qdict_next(reopen_state->options, entry)));
|
|
}
|
|
|
|
ret = 0;
|
|
|
|
/* Restore the original reopen_state->options QDict */
|
|
qobject_unref(reopen_state->options);
|
|
reopen_state->options = qobject_ref(orig_reopen_opts);
|
|
|
|
error:
|
|
if (ret < 0 && drv_prepared) {
|
|
/* drv->bdrv_reopen_prepare() has succeeded, so we need to
|
|
* call drv->bdrv_reopen_abort() before signaling an error
|
|
* (bdrv_reopen_multiple() will not call bdrv_reopen_abort()
|
|
* when the respective bdrv_reopen_prepare() has failed) */
|
|
if (drv->bdrv_reopen_abort) {
|
|
drv->bdrv_reopen_abort(reopen_state);
|
|
}
|
|
}
|
|
qemu_opts_del(opts);
|
|
qobject_unref(orig_reopen_opts);
|
|
g_free(discard);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Takes the staged changes for the reopen from bdrv_reopen_prepare(), and
|
|
* makes them final by swapping the staging BlockDriverState contents into
|
|
* the active BlockDriverState contents.
|
|
*/
|
|
static void bdrv_reopen_commit(BDRVReopenState *reopen_state)
|
|
{
|
|
BlockDriver *drv;
|
|
BlockDriverState *bs;
|
|
BdrvChild *child;
|
|
|
|
assert(reopen_state != NULL);
|
|
bs = reopen_state->bs;
|
|
drv = bs->drv;
|
|
assert(drv != NULL);
|
|
|
|
/* If there are any driver level actions to take */
|
|
if (drv->bdrv_reopen_commit) {
|
|
drv->bdrv_reopen_commit(reopen_state);
|
|
}
|
|
|
|
/* set BDS specific flags now */
|
|
qobject_unref(bs->explicit_options);
|
|
qobject_unref(bs->options);
|
|
|
|
bs->explicit_options = reopen_state->explicit_options;
|
|
bs->options = reopen_state->options;
|
|
bs->open_flags = reopen_state->flags;
|
|
bs->detect_zeroes = reopen_state->detect_zeroes;
|
|
|
|
if (reopen_state->replace_backing_bs) {
|
|
qdict_del(bs->explicit_options, "backing");
|
|
qdict_del(bs->options, "backing");
|
|
}
|
|
|
|
/* Remove child references from bs->options and bs->explicit_options.
|
|
* Child options were already removed in bdrv_reopen_queue_child() */
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
qdict_del(bs->explicit_options, child->name);
|
|
qdict_del(bs->options, child->name);
|
|
}
|
|
bdrv_refresh_limits(bs, NULL, NULL);
|
|
}
|
|
|
|
/*
|
|
* Abort the reopen, and delete and free the staged changes in
|
|
* reopen_state
|
|
*/
|
|
static void bdrv_reopen_abort(BDRVReopenState *reopen_state)
|
|
{
|
|
BlockDriver *drv;
|
|
|
|
assert(reopen_state != NULL);
|
|
drv = reopen_state->bs->drv;
|
|
assert(drv != NULL);
|
|
|
|
if (drv->bdrv_reopen_abort) {
|
|
drv->bdrv_reopen_abort(reopen_state);
|
|
}
|
|
}
|
|
|
|
|
|
static void bdrv_close(BlockDriverState *bs)
|
|
{
|
|
BdrvAioNotifier *ban, *ban_next;
|
|
BdrvChild *child, *next;
|
|
|
|
assert(!bs->refcnt);
|
|
|
|
bdrv_drained_begin(bs); /* complete I/O */
|
|
bdrv_flush(bs);
|
|
bdrv_drain(bs); /* in case flush left pending I/O */
|
|
|
|
if (bs->drv) {
|
|
if (bs->drv->bdrv_close) {
|
|
/* Must unfreeze all children, so bdrv_unref_child() works */
|
|
bs->drv->bdrv_close(bs);
|
|
}
|
|
bs->drv = NULL;
|
|
}
|
|
|
|
QLIST_FOREACH_SAFE(child, &bs->children, next, next) {
|
|
bdrv_unref_child(bs, child);
|
|
}
|
|
|
|
bs->backing = NULL;
|
|
bs->file = NULL;
|
|
g_free(bs->opaque);
|
|
bs->opaque = NULL;
|
|
qatomic_set(&bs->copy_on_read, 0);
|
|
bs->backing_file[0] = '\0';
|
|
bs->backing_format[0] = '\0';
|
|
bs->total_sectors = 0;
|
|
bs->encrypted = false;
|
|
bs->sg = false;
|
|
qobject_unref(bs->options);
|
|
qobject_unref(bs->explicit_options);
|
|
bs->options = NULL;
|
|
bs->explicit_options = NULL;
|
|
qobject_unref(bs->full_open_options);
|
|
bs->full_open_options = NULL;
|
|
|
|
bdrv_release_named_dirty_bitmaps(bs);
|
|
assert(QLIST_EMPTY(&bs->dirty_bitmaps));
|
|
|
|
QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) {
|
|
g_free(ban);
|
|
}
|
|
QLIST_INIT(&bs->aio_notifiers);
|
|
bdrv_drained_end(bs);
|
|
|
|
/*
|
|
* If we're still inside some bdrv_drain_all_begin()/end() sections, end
|
|
* them now since this BDS won't exist anymore when bdrv_drain_all_end()
|
|
* gets called.
|
|
*/
|
|
if (bs->quiesce_counter) {
|
|
bdrv_drain_all_end_quiesce(bs);
|
|
}
|
|
}
|
|
|
|
void bdrv_close_all(void)
|
|
{
|
|
assert(job_next(NULL) == NULL);
|
|
|
|
/* Drop references from requests still in flight, such as canceled block
|
|
* jobs whose AIO context has not been polled yet */
|
|
bdrv_drain_all();
|
|
|
|
blk_remove_all_bs();
|
|
blockdev_close_all_bdrv_states();
|
|
|
|
assert(QTAILQ_EMPTY(&all_bdrv_states));
|
|
}
|
|
|
|
static bool should_update_child(BdrvChild *c, BlockDriverState *to)
|
|
{
|
|
GQueue *queue;
|
|
GHashTable *found;
|
|
bool ret;
|
|
|
|
if (c->klass->stay_at_node) {
|
|
return false;
|
|
}
|
|
|
|
/* If the child @c belongs to the BDS @to, replacing the current
|
|
* c->bs by @to would mean to create a loop.
|
|
*
|
|
* Such a case occurs when appending a BDS to a backing chain.
|
|
* For instance, imagine the following chain:
|
|
*
|
|
* guest device -> node A -> further backing chain...
|
|
*
|
|
* Now we create a new BDS B which we want to put on top of this
|
|
* chain, so we first attach A as its backing node:
|
|
*
|
|
* node B
|
|
* |
|
|
* v
|
|
* guest device -> node A -> further backing chain...
|
|
*
|
|
* Finally we want to replace A by B. When doing that, we want to
|
|
* replace all pointers to A by pointers to B -- except for the
|
|
* pointer from B because (1) that would create a loop, and (2)
|
|
* that pointer should simply stay intact:
|
|
*
|
|
* guest device -> node B
|
|
* |
|
|
* v
|
|
* node A -> further backing chain...
|
|
*
|
|
* In general, when replacing a node A (c->bs) by a node B (@to),
|
|
* if A is a child of B, that means we cannot replace A by B there
|
|
* because that would create a loop. Silently detaching A from B
|
|
* is also not really an option. So overall just leaving A in
|
|
* place there is the most sensible choice.
|
|
*
|
|
* We would also create a loop in any cases where @c is only
|
|
* indirectly referenced by @to. Prevent this by returning false
|
|
* if @c is found (by breadth-first search) anywhere in the whole
|
|
* subtree of @to.
|
|
*/
|
|
|
|
ret = true;
|
|
found = g_hash_table_new(NULL, NULL);
|
|
g_hash_table_add(found, to);
|
|
queue = g_queue_new();
|
|
g_queue_push_tail(queue, to);
|
|
|
|
while (!g_queue_is_empty(queue)) {
|
|
BlockDriverState *v = g_queue_pop_head(queue);
|
|
BdrvChild *c2;
|
|
|
|
QLIST_FOREACH(c2, &v->children, next) {
|
|
if (c2 == c) {
|
|
ret = false;
|
|
break;
|
|
}
|
|
|
|
if (g_hash_table_contains(found, c2->bs)) {
|
|
continue;
|
|
}
|
|
|
|
g_queue_push_tail(queue, c2->bs);
|
|
g_hash_table_add(found, c2->bs);
|
|
}
|
|
}
|
|
|
|
g_queue_free(queue);
|
|
g_hash_table_destroy(found);
|
|
|
|
return ret;
|
|
}
|
|
|
|
typedef struct BdrvRemoveFilterOrCowChild {
|
|
BdrvChild *child;
|
|
bool is_backing;
|
|
} BdrvRemoveFilterOrCowChild;
|
|
|
|
static void bdrv_remove_filter_or_cow_child_abort(void *opaque)
|
|
{
|
|
BdrvRemoveFilterOrCowChild *s = opaque;
|
|
BlockDriverState *parent_bs = s->child->opaque;
|
|
|
|
QLIST_INSERT_HEAD(&parent_bs->children, s->child, next);
|
|
if (s->is_backing) {
|
|
parent_bs->backing = s->child;
|
|
} else {
|
|
parent_bs->file = s->child;
|
|
}
|
|
|
|
/*
|
|
* We don't have to restore child->bs here to undo bdrv_replace_child()
|
|
* because that function is transactionable and it registered own completion
|
|
* entries in @tran, so .abort() for bdrv_replace_child_safe() will be
|
|
* called automatically.
|
|
*/
|
|
}
|
|
|
|
static void bdrv_remove_filter_or_cow_child_commit(void *opaque)
|
|
{
|
|
BdrvRemoveFilterOrCowChild *s = opaque;
|
|
|
|
bdrv_child_free(s->child);
|
|
}
|
|
|
|
static TransactionActionDrv bdrv_remove_filter_or_cow_child_drv = {
|
|
.abort = bdrv_remove_filter_or_cow_child_abort,
|
|
.commit = bdrv_remove_filter_or_cow_child_commit,
|
|
.clean = g_free,
|
|
};
|
|
|
|
/*
|
|
* A function to remove backing-chain child of @bs if exists: cow child for
|
|
* format nodes (always .backing) and filter child for filters (may be .file or
|
|
* .backing)
|
|
*/
|
|
static void bdrv_remove_filter_or_cow_child(BlockDriverState *bs,
|
|
Transaction *tran)
|
|
{
|
|
BdrvRemoveFilterOrCowChild *s;
|
|
BdrvChild *child = bdrv_filter_or_cow_child(bs);
|
|
|
|
if (!child) {
|
|
return;
|
|
}
|
|
|
|
if (child->bs) {
|
|
bdrv_replace_child(child, NULL, tran);
|
|
}
|
|
|
|
s = g_new(BdrvRemoveFilterOrCowChild, 1);
|
|
*s = (BdrvRemoveFilterOrCowChild) {
|
|
.child = child,
|
|
.is_backing = (child == bs->backing),
|
|
};
|
|
tran_add(tran, &bdrv_remove_filter_or_cow_child_drv, s);
|
|
|
|
QLIST_SAFE_REMOVE(child, next);
|
|
if (s->is_backing) {
|
|
bs->backing = NULL;
|
|
} else {
|
|
bs->file = NULL;
|
|
}
|
|
}
|
|
|
|
static int bdrv_replace_node_noperm(BlockDriverState *from,
|
|
BlockDriverState *to,
|
|
bool auto_skip, Transaction *tran,
|
|
Error **errp)
|
|
{
|
|
BdrvChild *c, *next;
|
|
|
|
QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) {
|
|
assert(c->bs == from);
|
|
if (!should_update_child(c, to)) {
|
|
if (auto_skip) {
|
|
continue;
|
|
}
|
|
error_setg(errp, "Should not change '%s' link to '%s'",
|
|
c->name, from->node_name);
|
|
return -EINVAL;
|
|
}
|
|
if (c->frozen) {
|
|
error_setg(errp, "Cannot change '%s' link to '%s'",
|
|
c->name, from->node_name);
|
|
return -EPERM;
|
|
}
|
|
bdrv_replace_child(c, to, tran);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* With auto_skip=true bdrv_replace_node_common skips updating from parents
|
|
* if it creates a parent-child relation loop or if parent is block-job.
|
|
*
|
|
* With auto_skip=false the error is returned if from has a parent which should
|
|
* not be updated.
|
|
*
|
|
* With @detach_subchain=true @to must be in a backing chain of @from. In this
|
|
* case backing link of the cow-parent of @to is removed.
|
|
*/
|
|
static int bdrv_replace_node_common(BlockDriverState *from,
|
|
BlockDriverState *to,
|
|
bool auto_skip, bool detach_subchain,
|
|
Error **errp)
|
|
{
|
|
Transaction *tran = tran_new();
|
|
g_autoptr(GHashTable) found = NULL;
|
|
g_autoptr(GSList) refresh_list = NULL;
|
|
BlockDriverState *to_cow_parent;
|
|
int ret;
|
|
|
|
if (detach_subchain) {
|
|
assert(bdrv_chain_contains(from, to));
|
|
assert(from != to);
|
|
for (to_cow_parent = from;
|
|
bdrv_filter_or_cow_bs(to_cow_parent) != to;
|
|
to_cow_parent = bdrv_filter_or_cow_bs(to_cow_parent))
|
|
{
|
|
;
|
|
}
|
|
}
|
|
|
|
/* Make sure that @from doesn't go away until we have successfully attached
|
|
* all of its parents to @to. */
|
|
bdrv_ref(from);
|
|
|
|
assert(qemu_get_current_aio_context() == qemu_get_aio_context());
|
|
assert(bdrv_get_aio_context(from) == bdrv_get_aio_context(to));
|
|
bdrv_drained_begin(from);
|
|
|
|
/*
|
|
* Do the replacement without permission update.
|
|
* Replacement may influence the permissions, we should calculate new
|
|
* permissions based on new graph. If we fail, we'll roll-back the
|
|
* replacement.
|
|
*/
|
|
ret = bdrv_replace_node_noperm(from, to, auto_skip, tran, errp);
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
|
|
if (detach_subchain) {
|
|
bdrv_remove_filter_or_cow_child(to_cow_parent, tran);
|
|
}
|
|
|
|
found = g_hash_table_new(NULL, NULL);
|
|
|
|
refresh_list = bdrv_topological_dfs(refresh_list, found, to);
|
|
refresh_list = bdrv_topological_dfs(refresh_list, found, from);
|
|
|
|
ret = bdrv_list_refresh_perms(refresh_list, NULL, tran, errp);
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
|
|
ret = 0;
|
|
|
|
out:
|
|
tran_finalize(tran, ret);
|
|
|
|
bdrv_drained_end(from);
|
|
bdrv_unref(from);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
|
|
Error **errp)
|
|
{
|
|
return bdrv_replace_node_common(from, to, true, false, errp);
|
|
}
|
|
|
|
int bdrv_drop_filter(BlockDriverState *bs, Error **errp)
|
|
{
|
|
return bdrv_replace_node_common(bs, bdrv_filter_or_cow_bs(bs), true, true,
|
|
errp);
|
|
}
|
|
|
|
/*
|
|
* Add new bs contents at the top of an image chain while the chain is
|
|
* live, while keeping required fields on the top layer.
|
|
*
|
|
* This will modify the BlockDriverState fields, and swap contents
|
|
* between bs_new and bs_top. Both bs_new and bs_top are modified.
|
|
*
|
|
* bs_new must not be attached to a BlockBackend and must not have backing
|
|
* child.
|
|
*
|
|
* This function does not create any image files.
|
|
*/
|
|
int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
|
|
Error **errp)
|
|
{
|
|
int ret;
|
|
Transaction *tran = tran_new();
|
|
|
|
assert(!bs_new->backing);
|
|
|
|
ret = bdrv_attach_child_noperm(bs_new, bs_top, "backing",
|
|
&child_of_bds, bdrv_backing_role(bs_new),
|
|
&bs_new->backing, tran, errp);
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
|
|
ret = bdrv_replace_node_noperm(bs_top, bs_new, true, tran, errp);
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
|
|
ret = bdrv_refresh_perms(bs_new, errp);
|
|
out:
|
|
tran_finalize(tran, ret);
|
|
|
|
bdrv_refresh_limits(bs_top, NULL, NULL);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void bdrv_delete(BlockDriverState *bs)
|
|
{
|
|
assert(bdrv_op_blocker_is_empty(bs));
|
|
assert(!bs->refcnt);
|
|
|
|
/* remove from list, if necessary */
|
|
if (bs->node_name[0] != '\0') {
|
|
QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list);
|
|
}
|
|
QTAILQ_REMOVE(&all_bdrv_states, bs, bs_list);
|
|
|
|
bdrv_close(bs);
|
|
|
|
g_free(bs);
|
|
}
|
|
|
|
BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options,
|
|
int flags, Error **errp)
|
|
{
|
|
BlockDriverState *new_node_bs;
|
|
Error *local_err = NULL;
|
|
|
|
new_node_bs = bdrv_open(NULL, NULL, node_options, flags, errp);
|
|
if (new_node_bs == NULL) {
|
|
error_prepend(errp, "Could not create node: ");
|
|
return NULL;
|
|
}
|
|
|
|
bdrv_drained_begin(bs);
|
|
bdrv_replace_node(bs, new_node_bs, &local_err);
|
|
bdrv_drained_end(bs);
|
|
|
|
if (local_err) {
|
|
bdrv_unref(new_node_bs);
|
|
error_propagate(errp, local_err);
|
|
return NULL;
|
|
}
|
|
|
|
return new_node_bs;
|
|
}
|
|
|
|
/*
|
|
* Run consistency checks on an image
|
|
*
|
|
* Returns 0 if the check could be completed (it doesn't mean that the image is
|
|
* free of errors) or -errno when an internal error occurred. The results of the
|
|
* check are stored in res.
|
|
*/
|
|
int coroutine_fn bdrv_co_check(BlockDriverState *bs,
|
|
BdrvCheckResult *res, BdrvCheckMode fix)
|
|
{
|
|
if (bs->drv == NULL) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
if (bs->drv->bdrv_co_check == NULL) {
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
memset(res, 0, sizeof(*res));
|
|
return bs->drv->bdrv_co_check(bs, res, fix);
|
|
}
|
|
|
|
/*
|
|
* Return values:
|
|
* 0 - success
|
|
* -EINVAL - backing format specified, but no file
|
|
* -ENOSPC - can't update the backing file because no space is left in the
|
|
* image file header
|
|
* -ENOTSUP - format driver doesn't support changing the backing file
|
|
*/
|
|
int bdrv_change_backing_file(BlockDriverState *bs, const char *backing_file,
|
|
const char *backing_fmt, bool warn)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
int ret;
|
|
|
|
if (!drv) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
|
|
/* Backing file format doesn't make sense without a backing file */
|
|
if (backing_fmt && !backing_file) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (warn && backing_file && !backing_fmt) {
|
|
warn_report("Deprecated use of backing file without explicit "
|
|
"backing format, use of this image requires "
|
|
"potentially unsafe format probing");
|
|
}
|
|
|
|
if (drv->bdrv_change_backing_file != NULL) {
|
|
ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
|
|
} else {
|
|
ret = -ENOTSUP;
|
|
}
|
|
|
|
if (ret == 0) {
|
|
pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: "");
|
|
pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: "");
|
|
pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file),
|
|
backing_file ?: "");
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Finds the first non-filter node above bs in the chain between
|
|
* active and bs. The returned node is either an immediate parent of
|
|
* bs, or there are only filter nodes between the two.
|
|
*
|
|
* Returns NULL if bs is not found in active's image chain,
|
|
* or if active == bs.
|
|
*
|
|
* Returns the bottommost base image if bs == NULL.
|
|
*/
|
|
BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
|
|
BlockDriverState *bs)
|
|
{
|
|
bs = bdrv_skip_filters(bs);
|
|
active = bdrv_skip_filters(active);
|
|
|
|
while (active) {
|
|
BlockDriverState *next = bdrv_backing_chain_next(active);
|
|
if (bs == next) {
|
|
return active;
|
|
}
|
|
active = next;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* Given a BDS, searches for the base layer. */
|
|
BlockDriverState *bdrv_find_base(BlockDriverState *bs)
|
|
{
|
|
return bdrv_find_overlay(bs, NULL);
|
|
}
|
|
|
|
/*
|
|
* Return true if at least one of the COW (backing) and filter links
|
|
* between @bs and @base is frozen. @errp is set if that's the case.
|
|
* @base must be reachable from @bs, or NULL.
|
|
*/
|
|
bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base,
|
|
Error **errp)
|
|
{
|
|
BlockDriverState *i;
|
|
BdrvChild *child;
|
|
|
|
for (i = bs; i != base; i = child_bs(child)) {
|
|
child = bdrv_filter_or_cow_child(i);
|
|
|
|
if (child && child->frozen) {
|
|
error_setg(errp, "Cannot change '%s' link from '%s' to '%s'",
|
|
child->name, i->node_name, child->bs->node_name);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Freeze all COW (backing) and filter links between @bs and @base.
|
|
* If any of the links is already frozen the operation is aborted and
|
|
* none of the links are modified.
|
|
* @base must be reachable from @bs, or NULL.
|
|
* Returns 0 on success. On failure returns < 0 and sets @errp.
|
|
*/
|
|
int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base,
|
|
Error **errp)
|
|
{
|
|
BlockDriverState *i;
|
|
BdrvChild *child;
|
|
|
|
if (bdrv_is_backing_chain_frozen(bs, base, errp)) {
|
|
return -EPERM;
|
|
}
|
|
|
|
for (i = bs; i != base; i = child_bs(child)) {
|
|
child = bdrv_filter_or_cow_child(i);
|
|
if (child && child->bs->never_freeze) {
|
|
error_setg(errp, "Cannot freeze '%s' link to '%s'",
|
|
child->name, child->bs->node_name);
|
|
return -EPERM;
|
|
}
|
|
}
|
|
|
|
for (i = bs; i != base; i = child_bs(child)) {
|
|
child = bdrv_filter_or_cow_child(i);
|
|
if (child) {
|
|
child->frozen = true;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Unfreeze all COW (backing) and filter links between @bs and @base.
|
|
* The caller must ensure that all links are frozen before using this
|
|
* function.
|
|
* @base must be reachable from @bs, or NULL.
|
|
*/
|
|
void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base)
|
|
{
|
|
BlockDriverState *i;
|
|
BdrvChild *child;
|
|
|
|
for (i = bs; i != base; i = child_bs(child)) {
|
|
child = bdrv_filter_or_cow_child(i);
|
|
if (child) {
|
|
assert(child->frozen);
|
|
child->frozen = false;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Drops images above 'base' up to and including 'top', and sets the image
|
|
* above 'top' to have base as its backing file.
|
|
*
|
|
* Requires that the overlay to 'top' is opened r/w, so that the backing file
|
|
* information in 'bs' can be properly updated.
|
|
*
|
|
* E.g., this will convert the following chain:
|
|
* bottom <- base <- intermediate <- top <- active
|
|
*
|
|
* to
|
|
*
|
|
* bottom <- base <- active
|
|
*
|
|
* It is allowed for bottom==base, in which case it converts:
|
|
*
|
|
* base <- intermediate <- top <- active
|
|
*
|
|
* to
|
|
*
|
|
* base <- active
|
|
*
|
|
* If backing_file_str is non-NULL, it will be used when modifying top's
|
|
* overlay image metadata.
|
|
*
|
|
* Error conditions:
|
|
* if active == top, that is considered an error
|
|
*
|
|
*/
|
|
int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
|
|
const char *backing_file_str)
|
|
{
|
|
BlockDriverState *explicit_top = top;
|
|
bool update_inherits_from;
|
|
BdrvChild *c;
|
|
Error *local_err = NULL;
|
|
int ret = -EIO;
|
|
g_autoptr(GSList) updated_children = NULL;
|
|
GSList *p;
|
|
|
|
bdrv_ref(top);
|
|
bdrv_subtree_drained_begin(top);
|
|
|
|
if (!top->drv || !base->drv) {
|
|
goto exit;
|
|
}
|
|
|
|
/* Make sure that base is in the backing chain of top */
|
|
if (!bdrv_chain_contains(top, base)) {
|
|
goto exit;
|
|
}
|
|
|
|
/* If 'base' recursively inherits from 'top' then we should set
|
|
* base->inherits_from to top->inherits_from after 'top' and all
|
|
* other intermediate nodes have been dropped.
|
|
* If 'top' is an implicit node (e.g. "commit_top") we should skip
|
|
* it because no one inherits from it. We use explicit_top for that. */
|
|
explicit_top = bdrv_skip_implicit_filters(explicit_top);
|
|
update_inherits_from = bdrv_inherits_from_recursive(base, explicit_top);
|
|
|
|
/* success - we can delete the intermediate states, and link top->base */
|
|
/* TODO Check graph modification op blockers (BLK_PERM_GRAPH_MOD) once
|
|
* we've figured out how they should work. */
|
|
if (!backing_file_str) {
|
|
bdrv_refresh_filename(base);
|
|
backing_file_str = base->filename;
|
|
}
|
|
|
|
QLIST_FOREACH(c, &top->parents, next_parent) {
|
|
updated_children = g_slist_prepend(updated_children, c);
|
|
}
|
|
|
|
/*
|
|
* It seems correct to pass detach_subchain=true here, but it triggers
|
|
* one more yet not fixed bug, when due to nested aio_poll loop we switch to
|
|
* another drained section, which modify the graph (for example, removing
|
|
* the child, which we keep in updated_children list). So, it's a TODO.
|
|
*
|
|
* Note, bug triggered if pass detach_subchain=true here and run
|
|
* test-bdrv-drain. test_drop_intermediate_poll() test-case will crash.
|
|
* That's a FIXME.
|
|
*/
|
|
bdrv_replace_node_common(top, base, false, false, &local_err);
|
|
if (local_err) {
|
|
error_report_err(local_err);
|
|
goto exit;
|
|
}
|
|
|
|
for (p = updated_children; p; p = p->next) {
|
|
c = p->data;
|
|
|
|
if (c->klass->update_filename) {
|
|
ret = c->klass->update_filename(c, base, backing_file_str,
|
|
&local_err);
|
|
if (ret < 0) {
|
|
/*
|
|
* TODO: Actually, we want to rollback all previous iterations
|
|
* of this loop, and (which is almost impossible) previous
|
|
* bdrv_replace_node()...
|
|
*
|
|
* Note, that c->klass->update_filename may lead to permission
|
|
* update, so it's a bad idea to call it inside permission
|
|
* update transaction of bdrv_replace_node.
|
|
*/
|
|
error_report_err(local_err);
|
|
goto exit;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (update_inherits_from) {
|
|
base->inherits_from = explicit_top->inherits_from;
|
|
}
|
|
|
|
ret = 0;
|
|
exit:
|
|
bdrv_subtree_drained_end(top);
|
|
bdrv_unref(top);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* Implementation of BlockDriver.bdrv_get_allocated_file_size() that
|
|
* sums the size of all data-bearing children. (This excludes backing
|
|
* children.)
|
|
*/
|
|
static int64_t bdrv_sum_allocated_file_size(BlockDriverState *bs)
|
|
{
|
|
BdrvChild *child;
|
|
int64_t child_size, sum = 0;
|
|
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
if (child->role & (BDRV_CHILD_DATA | BDRV_CHILD_METADATA |
|
|
BDRV_CHILD_FILTERED))
|
|
{
|
|
child_size = bdrv_get_allocated_file_size(child->bs);
|
|
if (child_size < 0) {
|
|
return child_size;
|
|
}
|
|
sum += child_size;
|
|
}
|
|
}
|
|
|
|
return sum;
|
|
}
|
|
|
|
/**
|
|
* Length of a allocated file in bytes. Sparse files are counted by actual
|
|
* allocated space. Return < 0 if error or unknown.
|
|
*/
|
|
int64_t bdrv_get_allocated_file_size(BlockDriverState *bs)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
if (!drv) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
if (drv->bdrv_get_allocated_file_size) {
|
|
return drv->bdrv_get_allocated_file_size(bs);
|
|
}
|
|
|
|
if (drv->bdrv_file_open) {
|
|
/*
|
|
* Protocol drivers default to -ENOTSUP (most of their data is
|
|
* not stored in any of their children (if they even have any),
|
|
* so there is no generic way to figure it out).
|
|
*/
|
|
return -ENOTSUP;
|
|
} else if (drv->is_filter) {
|
|
/* Filter drivers default to the size of their filtered child */
|
|
return bdrv_get_allocated_file_size(bdrv_filter_bs(bs));
|
|
} else {
|
|
/* Other drivers default to summing their children's sizes */
|
|
return bdrv_sum_allocated_file_size(bs);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* bdrv_measure:
|
|
* @drv: Format driver
|
|
* @opts: Creation options for new image
|
|
* @in_bs: Existing image containing data for new image (may be NULL)
|
|
* @errp: Error object
|
|
* Returns: A #BlockMeasureInfo (free using qapi_free_BlockMeasureInfo())
|
|
* or NULL on error
|
|
*
|
|
* Calculate file size required to create a new image.
|
|
*
|
|
* If @in_bs is given then space for allocated clusters and zero clusters
|
|
* from that image are included in the calculation. If @opts contains a
|
|
* backing file that is shared by @in_bs then backing clusters may be omitted
|
|
* from the calculation.
|
|
*
|
|
* If @in_bs is NULL then the calculation includes no allocated clusters
|
|
* unless a preallocation option is given in @opts.
|
|
*
|
|
* Note that @in_bs may use a different BlockDriver from @drv.
|
|
*
|
|
* If an error occurs the @errp pointer is set.
|
|
*/
|
|
BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts,
|
|
BlockDriverState *in_bs, Error **errp)
|
|
{
|
|
if (!drv->bdrv_measure) {
|
|
error_setg(errp, "Block driver '%s' does not support size measurement",
|
|
drv->format_name);
|
|
return NULL;
|
|
}
|
|
|
|
return drv->bdrv_measure(opts, in_bs, errp);
|
|
}
|
|
|
|
/**
|
|
* Return number of sectors on success, -errno on error.
|
|
*/
|
|
int64_t bdrv_nb_sectors(BlockDriverState *bs)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
|
|
if (!drv)
|
|
return -ENOMEDIUM;
|
|
|
|
if (drv->has_variable_length) {
|
|
int ret = refresh_total_sectors(bs, bs->total_sectors);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
return bs->total_sectors;
|
|
}
|
|
|
|
/**
|
|
* Return length in bytes on success, -errno on error.
|
|
* The length is always a multiple of BDRV_SECTOR_SIZE.
|
|
*/
|
|
int64_t bdrv_getlength(BlockDriverState *bs)
|
|
{
|
|
int64_t ret = bdrv_nb_sectors(bs);
|
|
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
if (ret > INT64_MAX / BDRV_SECTOR_SIZE) {
|
|
return -EFBIG;
|
|
}
|
|
return ret * BDRV_SECTOR_SIZE;
|
|
}
|
|
|
|
/* return 0 as number of sectors if no device present or error */
|
|
void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
|
|
{
|
|
int64_t nb_sectors = bdrv_nb_sectors(bs);
|
|
|
|
*nb_sectors_ptr = nb_sectors < 0 ? 0 : nb_sectors;
|
|
}
|
|
|
|
bool bdrv_is_sg(BlockDriverState *bs)
|
|
{
|
|
return bs->sg;
|
|
}
|
|
|
|
/**
|
|
* Return whether the given node supports compressed writes.
|
|
*/
|
|
bool bdrv_supports_compressed_writes(BlockDriverState *bs)
|
|
{
|
|
BlockDriverState *filtered;
|
|
|
|
if (!bs->drv || !block_driver_can_compress(bs->drv)) {
|
|
return false;
|
|
}
|
|
|
|
filtered = bdrv_filter_bs(bs);
|
|
if (filtered) {
|
|
/*
|
|
* Filters can only forward compressed writes, so we have to
|
|
* check the child.
|
|
*/
|
|
return bdrv_supports_compressed_writes(filtered);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
const char *bdrv_get_format_name(BlockDriverState *bs)
|
|
{
|
|
return bs->drv ? bs->drv->format_name : NULL;
|
|
}
|
|
|
|
static int qsort_strcmp(const void *a, const void *b)
|
|
{
|
|
return strcmp(*(char *const *)a, *(char *const *)b);
|
|
}
|
|
|
|
void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
|
|
void *opaque, bool read_only)
|
|
{
|
|
BlockDriver *drv;
|
|
int count = 0;
|
|
int i;
|
|
const char **formats = NULL;
|
|
|
|
QLIST_FOREACH(drv, &bdrv_drivers, list) {
|
|
if (drv->format_name) {
|
|
bool found = false;
|
|
int i = count;
|
|
|
|
if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, read_only)) {
|
|
continue;
|
|
}
|
|
|
|
while (formats && i && !found) {
|
|
found = !strcmp(formats[--i], drv->format_name);
|
|
}
|
|
|
|
if (!found) {
|
|
formats = g_renew(const char *, formats, count + 1);
|
|
formats[count++] = drv->format_name;
|
|
}
|
|
}
|
|
}
|
|
|
|
for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); i++) {
|
|
const char *format_name = block_driver_modules[i].format_name;
|
|
|
|
if (format_name) {
|
|
bool found = false;
|
|
int j = count;
|
|
|
|
if (use_bdrv_whitelist &&
|
|
!bdrv_format_is_whitelisted(format_name, read_only)) {
|
|
continue;
|
|
}
|
|
|
|
while (formats && j && !found) {
|
|
found = !strcmp(formats[--j], format_name);
|
|
}
|
|
|
|
if (!found) {
|
|
formats = g_renew(const char *, formats, count + 1);
|
|
formats[count++] = format_name;
|
|
}
|
|
}
|
|
}
|
|
|
|
qsort(formats, count, sizeof(formats[0]), qsort_strcmp);
|
|
|
|
for (i = 0; i < count; i++) {
|
|
it(opaque, formats[i]);
|
|
}
|
|
|
|
g_free(formats);
|
|
}
|
|
|
|
/* This function is to find a node in the bs graph */
|
|
BlockDriverState *bdrv_find_node(const char *node_name)
|
|
{
|
|
BlockDriverState *bs;
|
|
|
|
assert(node_name);
|
|
|
|
QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
|
|
if (!strcmp(node_name, bs->node_name)) {
|
|
return bs;
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/* Put this QMP function here so it can access the static graph_bdrv_states. */
|
|
BlockDeviceInfoList *bdrv_named_nodes_list(bool flat,
|
|
Error **errp)
|
|
{
|
|
BlockDeviceInfoList *list;
|
|
BlockDriverState *bs;
|
|
|
|
list = NULL;
|
|
QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
|
|
BlockDeviceInfo *info = bdrv_block_device_info(NULL, bs, flat, errp);
|
|
if (!info) {
|
|
qapi_free_BlockDeviceInfoList(list);
|
|
return NULL;
|
|
}
|
|
QAPI_LIST_PREPEND(list, info);
|
|
}
|
|
|
|
return list;
|
|
}
|
|
|
|
typedef struct XDbgBlockGraphConstructor {
|
|
XDbgBlockGraph *graph;
|
|
GHashTable *graph_nodes;
|
|
} XDbgBlockGraphConstructor;
|
|
|
|
static XDbgBlockGraphConstructor *xdbg_graph_new(void)
|
|
{
|
|
XDbgBlockGraphConstructor *gr = g_new(XDbgBlockGraphConstructor, 1);
|
|
|
|
gr->graph = g_new0(XDbgBlockGraph, 1);
|
|
gr->graph_nodes = g_hash_table_new(NULL, NULL);
|
|
|
|
return gr;
|
|
}
|
|
|
|
static XDbgBlockGraph *xdbg_graph_finalize(XDbgBlockGraphConstructor *gr)
|
|
{
|
|
XDbgBlockGraph *graph = gr->graph;
|
|
|
|
g_hash_table_destroy(gr->graph_nodes);
|
|
g_free(gr);
|
|
|
|
return graph;
|
|
}
|
|
|
|
static uintptr_t xdbg_graph_node_num(XDbgBlockGraphConstructor *gr, void *node)
|
|
{
|
|
uintptr_t ret = (uintptr_t)g_hash_table_lookup(gr->graph_nodes, node);
|
|
|
|
if (ret != 0) {
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Start counting from 1, not 0, because 0 interferes with not-found (NULL)
|
|
* answer of g_hash_table_lookup.
|
|
*/
|
|
ret = g_hash_table_size(gr->graph_nodes) + 1;
|
|
g_hash_table_insert(gr->graph_nodes, node, (void *)ret);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void xdbg_graph_add_node(XDbgBlockGraphConstructor *gr, void *node,
|
|
XDbgBlockGraphNodeType type, const char *name)
|
|
{
|
|
XDbgBlockGraphNode *n;
|
|
|
|
n = g_new0(XDbgBlockGraphNode, 1);
|
|
|
|
n->id = xdbg_graph_node_num(gr, node);
|
|
n->type = type;
|
|
n->name = g_strdup(name);
|
|
|
|
QAPI_LIST_PREPEND(gr->graph->nodes, n);
|
|
}
|
|
|
|
static void xdbg_graph_add_edge(XDbgBlockGraphConstructor *gr, void *parent,
|
|
const BdrvChild *child)
|
|
{
|
|
BlockPermission qapi_perm;
|
|
XDbgBlockGraphEdge *edge;
|
|
|
|
edge = g_new0(XDbgBlockGraphEdge, 1);
|
|
|
|
edge->parent = xdbg_graph_node_num(gr, parent);
|
|
edge->child = xdbg_graph_node_num(gr, child->bs);
|
|
edge->name = g_strdup(child->name);
|
|
|
|
for (qapi_perm = 0; qapi_perm < BLOCK_PERMISSION__MAX; qapi_perm++) {
|
|
uint64_t flag = bdrv_qapi_perm_to_blk_perm(qapi_perm);
|
|
|
|
if (flag & child->perm) {
|
|
QAPI_LIST_PREPEND(edge->perm, qapi_perm);
|
|
}
|
|
if (flag & child->shared_perm) {
|
|
QAPI_LIST_PREPEND(edge->shared_perm, qapi_perm);
|
|
}
|
|
}
|
|
|
|
QAPI_LIST_PREPEND(gr->graph->edges, edge);
|
|
}
|
|
|
|
|
|
XDbgBlockGraph *bdrv_get_xdbg_block_graph(Error **errp)
|
|
{
|
|
BlockBackend *blk;
|
|
BlockJob *job;
|
|
BlockDriverState *bs;
|
|
BdrvChild *child;
|
|
XDbgBlockGraphConstructor *gr = xdbg_graph_new();
|
|
|
|
for (blk = blk_all_next(NULL); blk; blk = blk_all_next(blk)) {
|
|
char *allocated_name = NULL;
|
|
const char *name = blk_name(blk);
|
|
|
|
if (!*name) {
|
|
name = allocated_name = blk_get_attached_dev_id(blk);
|
|
}
|
|
xdbg_graph_add_node(gr, blk, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_BACKEND,
|
|
name);
|
|
g_free(allocated_name);
|
|
if (blk_root(blk)) {
|
|
xdbg_graph_add_edge(gr, blk, blk_root(blk));
|
|
}
|
|
}
|
|
|
|
for (job = block_job_next(NULL); job; job = block_job_next(job)) {
|
|
GSList *el;
|
|
|
|
xdbg_graph_add_node(gr, job, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_JOB,
|
|
job->job.id);
|
|
for (el = job->nodes; el; el = el->next) {
|
|
xdbg_graph_add_edge(gr, job, (BdrvChild *)el->data);
|
|
}
|
|
}
|
|
|
|
QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
|
|
xdbg_graph_add_node(gr, bs, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_DRIVER,
|
|
bs->node_name);
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
xdbg_graph_add_edge(gr, bs, child);
|
|
}
|
|
}
|
|
|
|
return xdbg_graph_finalize(gr);
|
|
}
|
|
|
|
BlockDriverState *bdrv_lookup_bs(const char *device,
|
|
const char *node_name,
|
|
Error **errp)
|
|
{
|
|
BlockBackend *blk;
|
|
BlockDriverState *bs;
|
|
|
|
if (device) {
|
|
blk = blk_by_name(device);
|
|
|
|
if (blk) {
|
|
bs = blk_bs(blk);
|
|
if (!bs) {
|
|
error_setg(errp, "Device '%s' has no medium", device);
|
|
}
|
|
|
|
return bs;
|
|
}
|
|
}
|
|
|
|
if (node_name) {
|
|
bs = bdrv_find_node(node_name);
|
|
|
|
if (bs) {
|
|
return bs;
|
|
}
|
|
}
|
|
|
|
error_setg(errp, "Cannot find device=\'%s\' nor node-name=\'%s\'",
|
|
device ? device : "",
|
|
node_name ? node_name : "");
|
|
return NULL;
|
|
}
|
|
|
|
/* If 'base' is in the same chain as 'top', return true. Otherwise,
|
|
* return false. If either argument is NULL, return false. */
|
|
bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base)
|
|
{
|
|
while (top && top != base) {
|
|
top = bdrv_filter_or_cow_bs(top);
|
|
}
|
|
|
|
return top != NULL;
|
|
}
|
|
|
|
BlockDriverState *bdrv_next_node(BlockDriverState *bs)
|
|
{
|
|
if (!bs) {
|
|
return QTAILQ_FIRST(&graph_bdrv_states);
|
|
}
|
|
return QTAILQ_NEXT(bs, node_list);
|
|
}
|
|
|
|
BlockDriverState *bdrv_next_all_states(BlockDriverState *bs)
|
|
{
|
|
if (!bs) {
|
|
return QTAILQ_FIRST(&all_bdrv_states);
|
|
}
|
|
return QTAILQ_NEXT(bs, bs_list);
|
|
}
|
|
|
|
const char *bdrv_get_node_name(const BlockDriverState *bs)
|
|
{
|
|
return bs->node_name;
|
|
}
|
|
|
|
const char *bdrv_get_parent_name(const BlockDriverState *bs)
|
|
{
|
|
BdrvChild *c;
|
|
const char *name;
|
|
|
|
/* If multiple parents have a name, just pick the first one. */
|
|
QLIST_FOREACH(c, &bs->parents, next_parent) {
|
|
if (c->klass->get_name) {
|
|
name = c->klass->get_name(c);
|
|
if (name && *name) {
|
|
return name;
|
|
}
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* TODO check what callers really want: bs->node_name or blk_name() */
|
|
const char *bdrv_get_device_name(const BlockDriverState *bs)
|
|
{
|
|
return bdrv_get_parent_name(bs) ?: "";
|
|
}
|
|
|
|
/* This can be used to identify nodes that might not have a device
|
|
* name associated. Since node and device names live in the same
|
|
* namespace, the result is unambiguous. The exception is if both are
|
|
* absent, then this returns an empty (non-null) string. */
|
|
const char *bdrv_get_device_or_node_name(const BlockDriverState *bs)
|
|
{
|
|
return bdrv_get_parent_name(bs) ?: bs->node_name;
|
|
}
|
|
|
|
int bdrv_get_flags(BlockDriverState *bs)
|
|
{
|
|
return bs->open_flags;
|
|
}
|
|
|
|
int bdrv_has_zero_init_1(BlockDriverState *bs)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
int bdrv_has_zero_init(BlockDriverState *bs)
|
|
{
|
|
BlockDriverState *filtered;
|
|
|
|
if (!bs->drv) {
|
|
return 0;
|
|
}
|
|
|
|
/* If BS is a copy on write image, it is initialized to
|
|
the contents of the base image, which may not be zeroes. */
|
|
if (bdrv_cow_child(bs)) {
|
|
return 0;
|
|
}
|
|
if (bs->drv->bdrv_has_zero_init) {
|
|
return bs->drv->bdrv_has_zero_init(bs);
|
|
}
|
|
|
|
filtered = bdrv_filter_bs(bs);
|
|
if (filtered) {
|
|
return bdrv_has_zero_init(filtered);
|
|
}
|
|
|
|
/* safe default */
|
|
return 0;
|
|
}
|
|
|
|
bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs)
|
|
{
|
|
if (!(bs->open_flags & BDRV_O_UNMAP)) {
|
|
return false;
|
|
}
|
|
|
|
return bs->supported_zero_flags & BDRV_REQ_MAY_UNMAP;
|
|
}
|
|
|
|
void bdrv_get_backing_filename(BlockDriverState *bs,
|
|
char *filename, int filename_size)
|
|
{
|
|
pstrcpy(filename, filename_size, bs->backing_file);
|
|
}
|
|
|
|
int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
|
|
{
|
|
int ret;
|
|
BlockDriver *drv = bs->drv;
|
|
/* if bs->drv == NULL, bs is closed, so there's nothing to do here */
|
|
if (!drv) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
if (!drv->bdrv_get_info) {
|
|
BlockDriverState *filtered = bdrv_filter_bs(bs);
|
|
if (filtered) {
|
|
return bdrv_get_info(filtered, bdi);
|
|
}
|
|
return -ENOTSUP;
|
|
}
|
|
memset(bdi, 0, sizeof(*bdi));
|
|
ret = drv->bdrv_get_info(bs, bdi);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
if (bdi->cluster_size > BDRV_MAX_ALIGNMENT) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs,
|
|
Error **errp)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
if (drv && drv->bdrv_get_specific_info) {
|
|
return drv->bdrv_get_specific_info(bs, errp);
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
BlockStatsSpecific *bdrv_get_specific_stats(BlockDriverState *bs)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
if (!drv || !drv->bdrv_get_specific_stats) {
|
|
return NULL;
|
|
}
|
|
return drv->bdrv_get_specific_stats(bs);
|
|
}
|
|
|
|
void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event)
|
|
{
|
|
if (!bs || !bs->drv || !bs->drv->bdrv_debug_event) {
|
|
return;
|
|
}
|
|
|
|
bs->drv->bdrv_debug_event(bs, event);
|
|
}
|
|
|
|
static BlockDriverState *bdrv_find_debug_node(BlockDriverState *bs)
|
|
{
|
|
while (bs && bs->drv && !bs->drv->bdrv_debug_breakpoint) {
|
|
bs = bdrv_primary_bs(bs);
|
|
}
|
|
|
|
if (bs && bs->drv && bs->drv->bdrv_debug_breakpoint) {
|
|
assert(bs->drv->bdrv_debug_remove_breakpoint);
|
|
return bs;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
|
|
const char *tag)
|
|
{
|
|
bs = bdrv_find_debug_node(bs);
|
|
if (bs) {
|
|
return bs->drv->bdrv_debug_breakpoint(bs, event, tag);
|
|
}
|
|
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag)
|
|
{
|
|
bs = bdrv_find_debug_node(bs);
|
|
if (bs) {
|
|
return bs->drv->bdrv_debug_remove_breakpoint(bs, tag);
|
|
}
|
|
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
int bdrv_debug_resume(BlockDriverState *bs, const char *tag)
|
|
{
|
|
while (bs && (!bs->drv || !bs->drv->bdrv_debug_resume)) {
|
|
bs = bdrv_primary_bs(bs);
|
|
}
|
|
|
|
if (bs && bs->drv && bs->drv->bdrv_debug_resume) {
|
|
return bs->drv->bdrv_debug_resume(bs, tag);
|
|
}
|
|
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag)
|
|
{
|
|
while (bs && bs->drv && !bs->drv->bdrv_debug_is_suspended) {
|
|
bs = bdrv_primary_bs(bs);
|
|
}
|
|
|
|
if (bs && bs->drv && bs->drv->bdrv_debug_is_suspended) {
|
|
return bs->drv->bdrv_debug_is_suspended(bs, tag);
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/* backing_file can either be relative, or absolute, or a protocol. If it is
|
|
* relative, it must be relative to the chain. So, passing in bs->filename
|
|
* from a BDS as backing_file should not be done, as that may be relative to
|
|
* the CWD rather than the chain. */
|
|
BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
|
|
const char *backing_file)
|
|
{
|
|
char *filename_full = NULL;
|
|
char *backing_file_full = NULL;
|
|
char *filename_tmp = NULL;
|
|
int is_protocol = 0;
|
|
bool filenames_refreshed = false;
|
|
BlockDriverState *curr_bs = NULL;
|
|
BlockDriverState *retval = NULL;
|
|
BlockDriverState *bs_below;
|
|
|
|
if (!bs || !bs->drv || !backing_file) {
|
|
return NULL;
|
|
}
|
|
|
|
filename_full = g_malloc(PATH_MAX);
|
|
backing_file_full = g_malloc(PATH_MAX);
|
|
|
|
is_protocol = path_has_protocol(backing_file);
|
|
|
|
/*
|
|
* Being largely a legacy function, skip any filters here
|
|
* (because filters do not have normal filenames, so they cannot
|
|
* match anyway; and allowing json:{} filenames is a bit out of
|
|
* scope).
|
|
*/
|
|
for (curr_bs = bdrv_skip_filters(bs);
|
|
bdrv_cow_child(curr_bs) != NULL;
|
|
curr_bs = bs_below)
|
|
{
|
|
bs_below = bdrv_backing_chain_next(curr_bs);
|
|
|
|
if (bdrv_backing_overridden(curr_bs)) {
|
|
/*
|
|
* If the backing file was overridden, we can only compare
|
|
* directly against the backing node's filename.
|
|
*/
|
|
|
|
if (!filenames_refreshed) {
|
|
/*
|
|
* This will automatically refresh all of the
|
|
* filenames in the rest of the backing chain, so we
|
|
* only need to do this once.
|
|
*/
|
|
bdrv_refresh_filename(bs_below);
|
|
filenames_refreshed = true;
|
|
}
|
|
|
|
if (strcmp(backing_file, bs_below->filename) == 0) {
|
|
retval = bs_below;
|
|
break;
|
|
}
|
|
} else if (is_protocol || path_has_protocol(curr_bs->backing_file)) {
|
|
/*
|
|
* If either of the filename paths is actually a protocol, then
|
|
* compare unmodified paths; otherwise make paths relative.
|
|
*/
|
|
char *backing_file_full_ret;
|
|
|
|
if (strcmp(backing_file, curr_bs->backing_file) == 0) {
|
|
retval = bs_below;
|
|
break;
|
|
}
|
|
/* Also check against the full backing filename for the image */
|
|
backing_file_full_ret = bdrv_get_full_backing_filename(curr_bs,
|
|
NULL);
|
|
if (backing_file_full_ret) {
|
|
bool equal = strcmp(backing_file, backing_file_full_ret) == 0;
|
|
g_free(backing_file_full_ret);
|
|
if (equal) {
|
|
retval = bs_below;
|
|
break;
|
|
}
|
|
}
|
|
} else {
|
|
/* If not an absolute filename path, make it relative to the current
|
|
* image's filename path */
|
|
filename_tmp = bdrv_make_absolute_filename(curr_bs, backing_file,
|
|
NULL);
|
|
/* We are going to compare canonicalized absolute pathnames */
|
|
if (!filename_tmp || !realpath(filename_tmp, filename_full)) {
|
|
g_free(filename_tmp);
|
|
continue;
|
|
}
|
|
g_free(filename_tmp);
|
|
|
|
/* We need to make sure the backing filename we are comparing against
|
|
* is relative to the current image filename (or absolute) */
|
|
filename_tmp = bdrv_get_full_backing_filename(curr_bs, NULL);
|
|
if (!filename_tmp || !realpath(filename_tmp, backing_file_full)) {
|
|
g_free(filename_tmp);
|
|
continue;
|
|
}
|
|
g_free(filename_tmp);
|
|
|
|
if (strcmp(backing_file_full, filename_full) == 0) {
|
|
retval = bs_below;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
g_free(filename_full);
|
|
g_free(backing_file_full);
|
|
return retval;
|
|
}
|
|
|
|
void bdrv_init(void)
|
|
{
|
|
module_call_init(MODULE_INIT_BLOCK);
|
|
}
|
|
|
|
void bdrv_init_with_whitelist(void)
|
|
{
|
|
use_bdrv_whitelist = 1;
|
|
bdrv_init();
|
|
}
|
|
|
|
int coroutine_fn bdrv_co_invalidate_cache(BlockDriverState *bs, Error **errp)
|
|
{
|
|
BdrvChild *child, *parent;
|
|
Error *local_err = NULL;
|
|
int ret;
|
|
BdrvDirtyBitmap *bm;
|
|
|
|
if (!bs->drv) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
bdrv_co_invalidate_cache(child->bs, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Update permissions, they may differ for inactive nodes.
|
|
*
|
|
* Note that the required permissions of inactive images are always a
|
|
* subset of the permissions required after activating the image. This
|
|
* allows us to just get the permissions upfront without restricting
|
|
* drv->bdrv_invalidate_cache().
|
|
*
|
|
* It also means that in error cases, we don't have to try and revert to
|
|
* the old permissions (which is an operation that could fail, too). We can
|
|
* just keep the extended permissions for the next time that an activation
|
|
* of the image is tried.
|
|
*/
|
|
if (bs->open_flags & BDRV_O_INACTIVE) {
|
|
bs->open_flags &= ~BDRV_O_INACTIVE;
|
|
ret = bdrv_refresh_perms(bs, errp);
|
|
if (ret < 0) {
|
|
bs->open_flags |= BDRV_O_INACTIVE;
|
|
return ret;
|
|
}
|
|
|
|
if (bs->drv->bdrv_co_invalidate_cache) {
|
|
bs->drv->bdrv_co_invalidate_cache(bs, &local_err);
|
|
if (local_err) {
|
|
bs->open_flags |= BDRV_O_INACTIVE;
|
|
error_propagate(errp, local_err);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
FOR_EACH_DIRTY_BITMAP(bs, bm) {
|
|
bdrv_dirty_bitmap_skip_store(bm, false);
|
|
}
|
|
|
|
ret = refresh_total_sectors(bs, bs->total_sectors);
|
|
if (ret < 0) {
|
|
bs->open_flags |= BDRV_O_INACTIVE;
|
|
error_setg_errno(errp, -ret, "Could not refresh total sector count");
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
QLIST_FOREACH(parent, &bs->parents, next_parent) {
|
|
if (parent->klass->activate) {
|
|
parent->klass->activate(parent, &local_err);
|
|
if (local_err) {
|
|
bs->open_flags |= BDRV_O_INACTIVE;
|
|
error_propagate(errp, local_err);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void bdrv_invalidate_cache_all(Error **errp)
|
|
{
|
|
BlockDriverState *bs;
|
|
BdrvNextIterator it;
|
|
|
|
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
|
|
AioContext *aio_context = bdrv_get_aio_context(bs);
|
|
int ret;
|
|
|
|
aio_context_acquire(aio_context);
|
|
ret = bdrv_invalidate_cache(bs, errp);
|
|
aio_context_release(aio_context);
|
|
if (ret < 0) {
|
|
bdrv_next_cleanup(&it);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
static bool bdrv_has_bds_parent(BlockDriverState *bs, bool only_active)
|
|
{
|
|
BdrvChild *parent;
|
|
|
|
QLIST_FOREACH(parent, &bs->parents, next_parent) {
|
|
if (parent->klass->parent_is_bds) {
|
|
BlockDriverState *parent_bs = parent->opaque;
|
|
if (!only_active || !(parent_bs->open_flags & BDRV_O_INACTIVE)) {
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static int bdrv_inactivate_recurse(BlockDriverState *bs)
|
|
{
|
|
BdrvChild *child, *parent;
|
|
int ret;
|
|
|
|
if (!bs->drv) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
|
|
/* Make sure that we don't inactivate a child before its parent.
|
|
* It will be covered by recursion from the yet active parent. */
|
|
if (bdrv_has_bds_parent(bs, true)) {
|
|
return 0;
|
|
}
|
|
|
|
assert(!(bs->open_flags & BDRV_O_INACTIVE));
|
|
|
|
/* Inactivate this node */
|
|
if (bs->drv->bdrv_inactivate) {
|
|
ret = bs->drv->bdrv_inactivate(bs);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
QLIST_FOREACH(parent, &bs->parents, next_parent) {
|
|
if (parent->klass->inactivate) {
|
|
ret = parent->klass->inactivate(parent);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
}
|
|
|
|
bs->open_flags |= BDRV_O_INACTIVE;
|
|
|
|
/*
|
|
* Update permissions, they may differ for inactive nodes.
|
|
* We only tried to loosen restrictions, so errors are not fatal, ignore
|
|
* them.
|
|
*/
|
|
bdrv_refresh_perms(bs, NULL);
|
|
|
|
/* Recursively inactivate children */
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
ret = bdrv_inactivate_recurse(child->bs);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int bdrv_inactivate_all(void)
|
|
{
|
|
BlockDriverState *bs = NULL;
|
|
BdrvNextIterator it;
|
|
int ret = 0;
|
|
GSList *aio_ctxs = NULL, *ctx;
|
|
|
|
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
|
|
AioContext *aio_context = bdrv_get_aio_context(bs);
|
|
|
|
if (!g_slist_find(aio_ctxs, aio_context)) {
|
|
aio_ctxs = g_slist_prepend(aio_ctxs, aio_context);
|
|
aio_context_acquire(aio_context);
|
|
}
|
|
}
|
|
|
|
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
|
|
/* Nodes with BDS parents are covered by recursion from the last
|
|
* parent that gets inactivated. Don't inactivate them a second
|
|
* time if that has already happened. */
|
|
if (bdrv_has_bds_parent(bs, false)) {
|
|
continue;
|
|
}
|
|
ret = bdrv_inactivate_recurse(bs);
|
|
if (ret < 0) {
|
|
bdrv_next_cleanup(&it);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
out:
|
|
for (ctx = aio_ctxs; ctx != NULL; ctx = ctx->next) {
|
|
AioContext *aio_context = ctx->data;
|
|
aio_context_release(aio_context);
|
|
}
|
|
g_slist_free(aio_ctxs);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**************************************************************/
|
|
/* removable device support */
|
|
|
|
/**
|
|
* Return TRUE if the media is present
|
|
*/
|
|
bool bdrv_is_inserted(BlockDriverState *bs)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
BdrvChild *child;
|
|
|
|
if (!drv) {
|
|
return false;
|
|
}
|
|
if (drv->bdrv_is_inserted) {
|
|
return drv->bdrv_is_inserted(bs);
|
|
}
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
if (!bdrv_is_inserted(child->bs)) {
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* If eject_flag is TRUE, eject the media. Otherwise, close the tray
|
|
*/
|
|
void bdrv_eject(BlockDriverState *bs, bool eject_flag)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
|
|
if (drv && drv->bdrv_eject) {
|
|
drv->bdrv_eject(bs, eject_flag);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Lock or unlock the media (if it is locked, the user won't be able
|
|
* to eject it manually).
|
|
*/
|
|
void bdrv_lock_medium(BlockDriverState *bs, bool locked)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
|
|
trace_bdrv_lock_medium(bs, locked);
|
|
|
|
if (drv && drv->bdrv_lock_medium) {
|
|
drv->bdrv_lock_medium(bs, locked);
|
|
}
|
|
}
|
|
|
|
/* Get a reference to bs */
|
|
void bdrv_ref(BlockDriverState *bs)
|
|
{
|
|
bs->refcnt++;
|
|
}
|
|
|
|
/* Release a previously grabbed reference to bs.
|
|
* If after releasing, reference count is zero, the BlockDriverState is
|
|
* deleted. */
|
|
void bdrv_unref(BlockDriverState *bs)
|
|
{
|
|
if (!bs) {
|
|
return;
|
|
}
|
|
assert(bs->refcnt > 0);
|
|
if (--bs->refcnt == 0) {
|
|
bdrv_delete(bs);
|
|
}
|
|
}
|
|
|
|
struct BdrvOpBlocker {
|
|
Error *reason;
|
|
QLIST_ENTRY(BdrvOpBlocker) list;
|
|
};
|
|
|
|
bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp)
|
|
{
|
|
BdrvOpBlocker *blocker;
|
|
assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
|
|
if (!QLIST_EMPTY(&bs->op_blockers[op])) {
|
|
blocker = QLIST_FIRST(&bs->op_blockers[op]);
|
|
error_propagate_prepend(errp, error_copy(blocker->reason),
|
|
"Node '%s' is busy: ",
|
|
bdrv_get_device_or_node_name(bs));
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason)
|
|
{
|
|
BdrvOpBlocker *blocker;
|
|
assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
|
|
|
|
blocker = g_new0(BdrvOpBlocker, 1);
|
|
blocker->reason = reason;
|
|
QLIST_INSERT_HEAD(&bs->op_blockers[op], blocker, list);
|
|
}
|
|
|
|
void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason)
|
|
{
|
|
BdrvOpBlocker *blocker, *next;
|
|
assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
|
|
QLIST_FOREACH_SAFE(blocker, &bs->op_blockers[op], list, next) {
|
|
if (blocker->reason == reason) {
|
|
QLIST_REMOVE(blocker, list);
|
|
g_free(blocker);
|
|
}
|
|
}
|
|
}
|
|
|
|
void bdrv_op_block_all(BlockDriverState *bs, Error *reason)
|
|
{
|
|
int i;
|
|
for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
|
|
bdrv_op_block(bs, i, reason);
|
|
}
|
|
}
|
|
|
|
void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason)
|
|
{
|
|
int i;
|
|
for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
|
|
bdrv_op_unblock(bs, i, reason);
|
|
}
|
|
}
|
|
|
|
bool bdrv_op_blocker_is_empty(BlockDriverState *bs)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
|
|
if (!QLIST_EMPTY(&bs->op_blockers[i])) {
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
void bdrv_img_create(const char *filename, const char *fmt,
|
|
const char *base_filename, const char *base_fmt,
|
|
char *options, uint64_t img_size, int flags, bool quiet,
|
|
Error **errp)
|
|
{
|
|
QemuOptsList *create_opts = NULL;
|
|
QemuOpts *opts = NULL;
|
|
const char *backing_fmt, *backing_file;
|
|
int64_t size;
|
|
BlockDriver *drv, *proto_drv;
|
|
Error *local_err = NULL;
|
|
int ret = 0;
|
|
|
|
/* Find driver and parse its options */
|
|
drv = bdrv_find_format(fmt);
|
|
if (!drv) {
|
|
error_setg(errp, "Unknown file format '%s'", fmt);
|
|
return;
|
|
}
|
|
|
|
proto_drv = bdrv_find_protocol(filename, true, errp);
|
|
if (!proto_drv) {
|
|
return;
|
|
}
|
|
|
|
if (!drv->create_opts) {
|
|
error_setg(errp, "Format driver '%s' does not support image creation",
|
|
drv->format_name);
|
|
return;
|
|
}
|
|
|
|
if (!proto_drv->create_opts) {
|
|
error_setg(errp, "Protocol driver '%s' does not support image creation",
|
|
proto_drv->format_name);
|
|
return;
|
|
}
|
|
|
|
/* Create parameter list */
|
|
create_opts = qemu_opts_append(create_opts, drv->create_opts);
|
|
create_opts = qemu_opts_append(create_opts, proto_drv->create_opts);
|
|
|
|
opts = qemu_opts_create(create_opts, NULL, 0, &error_abort);
|
|
|
|
/* Parse -o options */
|
|
if (options) {
|
|
if (!qemu_opts_do_parse(opts, options, NULL, errp)) {
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (!qemu_opt_get(opts, BLOCK_OPT_SIZE)) {
|
|
qemu_opt_set_number(opts, BLOCK_OPT_SIZE, img_size, &error_abort);
|
|
} else if (img_size != UINT64_C(-1)) {
|
|
error_setg(errp, "The image size must be specified only once");
|
|
goto out;
|
|
}
|
|
|
|
if (base_filename) {
|
|
if (!qemu_opt_set(opts, BLOCK_OPT_BACKING_FILE, base_filename,
|
|
NULL)) {
|
|
error_setg(errp, "Backing file not supported for file format '%s'",
|
|
fmt);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (base_fmt) {
|
|
if (!qemu_opt_set(opts, BLOCK_OPT_BACKING_FMT, base_fmt, NULL)) {
|
|
error_setg(errp, "Backing file format not supported for file "
|
|
"format '%s'", fmt);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE);
|
|
if (backing_file) {
|
|
if (!strcmp(filename, backing_file)) {
|
|
error_setg(errp, "Error: Trying to create an image with the "
|
|
"same filename as the backing file");
|
|
goto out;
|
|
}
|
|
if (backing_file[0] == '\0') {
|
|
error_setg(errp, "Expected backing file name, got empty string");
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
backing_fmt = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT);
|
|
|
|
/* The size for the image must always be specified, unless we have a backing
|
|
* file and we have not been forbidden from opening it. */
|
|
size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, img_size);
|
|
if (backing_file && !(flags & BDRV_O_NO_BACKING)) {
|
|
BlockDriverState *bs;
|
|
char *full_backing;
|
|
int back_flags;
|
|
QDict *backing_options = NULL;
|
|
|
|
full_backing =
|
|
bdrv_get_full_backing_filename_from_filename(filename, backing_file,
|
|
&local_err);
|
|
if (local_err) {
|
|
goto out;
|
|
}
|
|
assert(full_backing);
|
|
|
|
/* backing files always opened read-only */
|
|
back_flags = flags;
|
|
back_flags &= ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
|
|
|
|
backing_options = qdict_new();
|
|
if (backing_fmt) {
|
|
qdict_put_str(backing_options, "driver", backing_fmt);
|
|
}
|
|
qdict_put_bool(backing_options, BDRV_OPT_FORCE_SHARE, true);
|
|
|
|
bs = bdrv_open(full_backing, NULL, backing_options, back_flags,
|
|
&local_err);
|
|
g_free(full_backing);
|
|
if (!bs) {
|
|
error_append_hint(&local_err, "Could not open backing image.\n");
|
|
goto out;
|
|
} else {
|
|
if (!backing_fmt) {
|
|
warn_report("Deprecated use of backing file without explicit "
|
|
"backing format (detected format of %s)",
|
|
bs->drv->format_name);
|
|
if (bs->drv != &bdrv_raw) {
|
|
/*
|
|
* A probe of raw deserves the most attention:
|
|
* leaving the backing format out of the image
|
|
* will ensure bs->probed is set (ensuring we
|
|
* don't accidentally commit into the backing
|
|
* file), and allow more spots to warn the users
|
|
* to fix their toolchain when opening this image
|
|
* later. For other images, we can safely record
|
|
* the format that we probed.
|
|
*/
|
|
backing_fmt = bs->drv->format_name;
|
|
qemu_opt_set(opts, BLOCK_OPT_BACKING_FMT, backing_fmt,
|
|
NULL);
|
|
}
|
|
}
|
|
if (size == -1) {
|
|
/* Opened BS, have no size */
|
|
size = bdrv_getlength(bs);
|
|
if (size < 0) {
|
|
error_setg_errno(errp, -size, "Could not get size of '%s'",
|
|
backing_file);
|
|
bdrv_unref(bs);
|
|
goto out;
|
|
}
|
|
qemu_opt_set_number(opts, BLOCK_OPT_SIZE, size, &error_abort);
|
|
}
|
|
bdrv_unref(bs);
|
|
}
|
|
/* (backing_file && !(flags & BDRV_O_NO_BACKING)) */
|
|
} else if (backing_file && !backing_fmt) {
|
|
warn_report("Deprecated use of unopened backing file without "
|
|
"explicit backing format, use of this image requires "
|
|
"potentially unsafe format probing");
|
|
}
|
|
|
|
if (size == -1) {
|
|
error_setg(errp, "Image creation needs a size parameter");
|
|
goto out;
|
|
}
|
|
|
|
if (!quiet) {
|
|
printf("Formatting '%s', fmt=%s ", filename, fmt);
|
|
qemu_opts_print(opts, " ");
|
|
puts("");
|
|
fflush(stdout);
|
|
}
|
|
|
|
ret = bdrv_create(drv, filename, opts, &local_err);
|
|
|
|
if (ret == -EFBIG) {
|
|
/* This is generally a better message than whatever the driver would
|
|
* deliver (especially because of the cluster_size_hint), since that
|
|
* is most probably not much different from "image too large". */
|
|
const char *cluster_size_hint = "";
|
|
if (qemu_opt_get_size(opts, BLOCK_OPT_CLUSTER_SIZE, 0)) {
|
|
cluster_size_hint = " (try using a larger cluster size)";
|
|
}
|
|
error_setg(errp, "The image size is too large for file format '%s'"
|
|
"%s", fmt, cluster_size_hint);
|
|
error_free(local_err);
|
|
local_err = NULL;
|
|
}
|
|
|
|
out:
|
|
qemu_opts_del(opts);
|
|
qemu_opts_free(create_opts);
|
|
error_propagate(errp, local_err);
|
|
}
|
|
|
|
AioContext *bdrv_get_aio_context(BlockDriverState *bs)
|
|
{
|
|
return bs ? bs->aio_context : qemu_get_aio_context();
|
|
}
|
|
|
|
AioContext *coroutine_fn bdrv_co_enter(BlockDriverState *bs)
|
|
{
|
|
Coroutine *self = qemu_coroutine_self();
|
|
AioContext *old_ctx = qemu_coroutine_get_aio_context(self);
|
|
AioContext *new_ctx;
|
|
|
|
/*
|
|
* Increase bs->in_flight to ensure that this operation is completed before
|
|
* moving the node to a different AioContext. Read new_ctx only afterwards.
|
|
*/
|
|
bdrv_inc_in_flight(bs);
|
|
|
|
new_ctx = bdrv_get_aio_context(bs);
|
|
aio_co_reschedule_self(new_ctx);
|
|
return old_ctx;
|
|
}
|
|
|
|
void coroutine_fn bdrv_co_leave(BlockDriverState *bs, AioContext *old_ctx)
|
|
{
|
|
aio_co_reschedule_self(old_ctx);
|
|
bdrv_dec_in_flight(bs);
|
|
}
|
|
|
|
void coroutine_fn bdrv_co_lock(BlockDriverState *bs)
|
|
{
|
|
AioContext *ctx = bdrv_get_aio_context(bs);
|
|
|
|
/* In the main thread, bs->aio_context won't change concurrently */
|
|
assert(qemu_get_current_aio_context() == qemu_get_aio_context());
|
|
|
|
/*
|
|
* We're in coroutine context, so we already hold the lock of the main
|
|
* loop AioContext. Don't lock it twice to avoid deadlocks.
|
|
*/
|
|
assert(qemu_in_coroutine());
|
|
if (ctx != qemu_get_aio_context()) {
|
|
aio_context_acquire(ctx);
|
|
}
|
|
}
|
|
|
|
void coroutine_fn bdrv_co_unlock(BlockDriverState *bs)
|
|
{
|
|
AioContext *ctx = bdrv_get_aio_context(bs);
|
|
|
|
assert(qemu_in_coroutine());
|
|
if (ctx != qemu_get_aio_context()) {
|
|
aio_context_release(ctx);
|
|
}
|
|
}
|
|
|
|
void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co)
|
|
{
|
|
aio_co_enter(bdrv_get_aio_context(bs), co);
|
|
}
|
|
|
|
static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier *ban)
|
|
{
|
|
QLIST_REMOVE(ban, list);
|
|
g_free(ban);
|
|
}
|
|
|
|
static void bdrv_detach_aio_context(BlockDriverState *bs)
|
|
{
|
|
BdrvAioNotifier *baf, *baf_tmp;
|
|
|
|
assert(!bs->walking_aio_notifiers);
|
|
bs->walking_aio_notifiers = true;
|
|
QLIST_FOREACH_SAFE(baf, &bs->aio_notifiers, list, baf_tmp) {
|
|
if (baf->deleted) {
|
|
bdrv_do_remove_aio_context_notifier(baf);
|
|
} else {
|
|
baf->detach_aio_context(baf->opaque);
|
|
}
|
|
}
|
|
/* Never mind iterating again to check for ->deleted. bdrv_close() will
|
|
* remove remaining aio notifiers if we aren't called again.
|
|
*/
|
|
bs->walking_aio_notifiers = false;
|
|
|
|
if (bs->drv && bs->drv->bdrv_detach_aio_context) {
|
|
bs->drv->bdrv_detach_aio_context(bs);
|
|
}
|
|
|
|
if (bs->quiesce_counter) {
|
|
aio_enable_external(bs->aio_context);
|
|
}
|
|
bs->aio_context = NULL;
|
|
}
|
|
|
|
static void bdrv_attach_aio_context(BlockDriverState *bs,
|
|
AioContext *new_context)
|
|
{
|
|
BdrvAioNotifier *ban, *ban_tmp;
|
|
|
|
if (bs->quiesce_counter) {
|
|
aio_disable_external(new_context);
|
|
}
|
|
|
|
bs->aio_context = new_context;
|
|
|
|
if (bs->drv && bs->drv->bdrv_attach_aio_context) {
|
|
bs->drv->bdrv_attach_aio_context(bs, new_context);
|
|
}
|
|
|
|
assert(!bs->walking_aio_notifiers);
|
|
bs->walking_aio_notifiers = true;
|
|
QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_tmp) {
|
|
if (ban->deleted) {
|
|
bdrv_do_remove_aio_context_notifier(ban);
|
|
} else {
|
|
ban->attached_aio_context(new_context, ban->opaque);
|
|
}
|
|
}
|
|
bs->walking_aio_notifiers = false;
|
|
}
|
|
|
|
/*
|
|
* Changes the AioContext used for fd handlers, timers, and BHs by this
|
|
* BlockDriverState and all its children and parents.
|
|
*
|
|
* Must be called from the main AioContext.
|
|
*
|
|
* The caller must own the AioContext lock for the old AioContext of bs, but it
|
|
* must not own the AioContext lock for new_context (unless new_context is the
|
|
* same as the current context of bs).
|
|
*
|
|
* @ignore will accumulate all visited BdrvChild object. The caller is
|
|
* responsible for freeing the list afterwards.
|
|
*/
|
|
void bdrv_set_aio_context_ignore(BlockDriverState *bs,
|
|
AioContext *new_context, GSList **ignore)
|
|
{
|
|
AioContext *old_context = bdrv_get_aio_context(bs);
|
|
GSList *children_to_process = NULL;
|
|
GSList *parents_to_process = NULL;
|
|
GSList *entry;
|
|
BdrvChild *child, *parent;
|
|
|
|
g_assert(qemu_get_current_aio_context() == qemu_get_aio_context());
|
|
|
|
if (old_context == new_context) {
|
|
return;
|
|
}
|
|
|
|
bdrv_drained_begin(bs);
|
|
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
if (g_slist_find(*ignore, child)) {
|
|
continue;
|
|
}
|
|
*ignore = g_slist_prepend(*ignore, child);
|
|
children_to_process = g_slist_prepend(children_to_process, child);
|
|
}
|
|
|
|
QLIST_FOREACH(parent, &bs->parents, next_parent) {
|
|
if (g_slist_find(*ignore, parent)) {
|
|
continue;
|
|
}
|
|
*ignore = g_slist_prepend(*ignore, parent);
|
|
parents_to_process = g_slist_prepend(parents_to_process, parent);
|
|
}
|
|
|
|
for (entry = children_to_process;
|
|
entry != NULL;
|
|
entry = g_slist_next(entry)) {
|
|
child = entry->data;
|
|
bdrv_set_aio_context_ignore(child->bs, new_context, ignore);
|
|
}
|
|
g_slist_free(children_to_process);
|
|
|
|
for (entry = parents_to_process;
|
|
entry != NULL;
|
|
entry = g_slist_next(entry)) {
|
|
parent = entry->data;
|
|
assert(parent->klass->set_aio_ctx);
|
|
parent->klass->set_aio_ctx(parent, new_context, ignore);
|
|
}
|
|
g_slist_free(parents_to_process);
|
|
|
|
bdrv_detach_aio_context(bs);
|
|
|
|
/* Acquire the new context, if necessary */
|
|
if (qemu_get_aio_context() != new_context) {
|
|
aio_context_acquire(new_context);
|
|
}
|
|
|
|
bdrv_attach_aio_context(bs, new_context);
|
|
|
|
/*
|
|
* If this function was recursively called from
|
|
* bdrv_set_aio_context_ignore(), there may be nodes in the
|
|
* subtree that have not yet been moved to the new AioContext.
|
|
* Release the old one so bdrv_drained_end() can poll them.
|
|
*/
|
|
if (qemu_get_aio_context() != old_context) {
|
|
aio_context_release(old_context);
|
|
}
|
|
|
|
bdrv_drained_end(bs);
|
|
|
|
if (qemu_get_aio_context() != old_context) {
|
|
aio_context_acquire(old_context);
|
|
}
|
|
if (qemu_get_aio_context() != new_context) {
|
|
aio_context_release(new_context);
|
|
}
|
|
}
|
|
|
|
static bool bdrv_parent_can_set_aio_context(BdrvChild *c, AioContext *ctx,
|
|
GSList **ignore, Error **errp)
|
|
{
|
|
if (g_slist_find(*ignore, c)) {
|
|
return true;
|
|
}
|
|
*ignore = g_slist_prepend(*ignore, c);
|
|
|
|
/*
|
|
* A BdrvChildClass that doesn't handle AioContext changes cannot
|
|
* tolerate any AioContext changes
|
|
*/
|
|
if (!c->klass->can_set_aio_ctx) {
|
|
char *user = bdrv_child_user_desc(c);
|
|
error_setg(errp, "Changing iothreads is not supported by %s", user);
|
|
g_free(user);
|
|
return false;
|
|
}
|
|
if (!c->klass->can_set_aio_ctx(c, ctx, ignore, errp)) {
|
|
assert(!errp || *errp);
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool bdrv_child_can_set_aio_context(BdrvChild *c, AioContext *ctx,
|
|
GSList **ignore, Error **errp)
|
|
{
|
|
if (g_slist_find(*ignore, c)) {
|
|
return true;
|
|
}
|
|
*ignore = g_slist_prepend(*ignore, c);
|
|
return bdrv_can_set_aio_context(c->bs, ctx, ignore, errp);
|
|
}
|
|
|
|
/* @ignore will accumulate all visited BdrvChild object. The caller is
|
|
* responsible for freeing the list afterwards. */
|
|
bool bdrv_can_set_aio_context(BlockDriverState *bs, AioContext *ctx,
|
|
GSList **ignore, Error **errp)
|
|
{
|
|
BdrvChild *c;
|
|
|
|
if (bdrv_get_aio_context(bs) == ctx) {
|
|
return true;
|
|
}
|
|
|
|
QLIST_FOREACH(c, &bs->parents, next_parent) {
|
|
if (!bdrv_parent_can_set_aio_context(c, ctx, ignore, errp)) {
|
|
return false;
|
|
}
|
|
}
|
|
QLIST_FOREACH(c, &bs->children, next) {
|
|
if (!bdrv_child_can_set_aio_context(c, ctx, ignore, errp)) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
int bdrv_child_try_set_aio_context(BlockDriverState *bs, AioContext *ctx,
|
|
BdrvChild *ignore_child, Error **errp)
|
|
{
|
|
GSList *ignore;
|
|
bool ret;
|
|
|
|
ignore = ignore_child ? g_slist_prepend(NULL, ignore_child) : NULL;
|
|
ret = bdrv_can_set_aio_context(bs, ctx, &ignore, errp);
|
|
g_slist_free(ignore);
|
|
|
|
if (!ret) {
|
|
return -EPERM;
|
|
}
|
|
|
|
ignore = ignore_child ? g_slist_prepend(NULL, ignore_child) : NULL;
|
|
bdrv_set_aio_context_ignore(bs, ctx, &ignore);
|
|
g_slist_free(ignore);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int bdrv_try_set_aio_context(BlockDriverState *bs, AioContext *ctx,
|
|
Error **errp)
|
|
{
|
|
return bdrv_child_try_set_aio_context(bs, ctx, NULL, errp);
|
|
}
|
|
|
|
void bdrv_add_aio_context_notifier(BlockDriverState *bs,
|
|
void (*attached_aio_context)(AioContext *new_context, void *opaque),
|
|
void (*detach_aio_context)(void *opaque), void *opaque)
|
|
{
|
|
BdrvAioNotifier *ban = g_new(BdrvAioNotifier, 1);
|
|
*ban = (BdrvAioNotifier){
|
|
.attached_aio_context = attached_aio_context,
|
|
.detach_aio_context = detach_aio_context,
|
|
.opaque = opaque
|
|
};
|
|
|
|
QLIST_INSERT_HEAD(&bs->aio_notifiers, ban, list);
|
|
}
|
|
|
|
void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
|
|
void (*attached_aio_context)(AioContext *,
|
|
void *),
|
|
void (*detach_aio_context)(void *),
|
|
void *opaque)
|
|
{
|
|
BdrvAioNotifier *ban, *ban_next;
|
|
|
|
QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) {
|
|
if (ban->attached_aio_context == attached_aio_context &&
|
|
ban->detach_aio_context == detach_aio_context &&
|
|
ban->opaque == opaque &&
|
|
ban->deleted == false)
|
|
{
|
|
if (bs->walking_aio_notifiers) {
|
|
ban->deleted = true;
|
|
} else {
|
|
bdrv_do_remove_aio_context_notifier(ban);
|
|
}
|
|
return;
|
|
}
|
|
}
|
|
|
|
abort();
|
|
}
|
|
|
|
int bdrv_amend_options(BlockDriverState *bs, QemuOpts *opts,
|
|
BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
|
|
bool force,
|
|
Error **errp)
|
|
{
|
|
if (!bs->drv) {
|
|
error_setg(errp, "Node is ejected");
|
|
return -ENOMEDIUM;
|
|
}
|
|
if (!bs->drv->bdrv_amend_options) {
|
|
error_setg(errp, "Block driver '%s' does not support option amendment",
|
|
bs->drv->format_name);
|
|
return -ENOTSUP;
|
|
}
|
|
return bs->drv->bdrv_amend_options(bs, opts, status_cb,
|
|
cb_opaque, force, errp);
|
|
}
|
|
|
|
/*
|
|
* This function checks whether the given @to_replace is allowed to be
|
|
* replaced by a node that always shows the same data as @bs. This is
|
|
* used for example to verify whether the mirror job can replace
|
|
* @to_replace by the target mirrored from @bs.
|
|
* To be replaceable, @bs and @to_replace may either be guaranteed to
|
|
* always show the same data (because they are only connected through
|
|
* filters), or some driver may allow replacing one of its children
|
|
* because it can guarantee that this child's data is not visible at
|
|
* all (for example, for dissenting quorum children that have no other
|
|
* parents).
|
|
*/
|
|
bool bdrv_recurse_can_replace(BlockDriverState *bs,
|
|
BlockDriverState *to_replace)
|
|
{
|
|
BlockDriverState *filtered;
|
|
|
|
if (!bs || !bs->drv) {
|
|
return false;
|
|
}
|
|
|
|
if (bs == to_replace) {
|
|
return true;
|
|
}
|
|
|
|
/* See what the driver can do */
|
|
if (bs->drv->bdrv_recurse_can_replace) {
|
|
return bs->drv->bdrv_recurse_can_replace(bs, to_replace);
|
|
}
|
|
|
|
/* For filters without an own implementation, we can recurse on our own */
|
|
filtered = bdrv_filter_bs(bs);
|
|
if (filtered) {
|
|
return bdrv_recurse_can_replace(filtered, to_replace);
|
|
}
|
|
|
|
/* Safe default */
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Check whether the given @node_name can be replaced by a node that
|
|
* has the same data as @parent_bs. If so, return @node_name's BDS;
|
|
* NULL otherwise.
|
|
*
|
|
* @node_name must be a (recursive) *child of @parent_bs (or this
|
|
* function will return NULL).
|
|
*
|
|
* The result (whether the node can be replaced or not) is only valid
|
|
* for as long as no graph or permission changes occur.
|
|
*/
|
|
BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
|
|
const char *node_name, Error **errp)
|
|
{
|
|
BlockDriverState *to_replace_bs = bdrv_find_node(node_name);
|
|
AioContext *aio_context;
|
|
|
|
if (!to_replace_bs) {
|
|
error_setg(errp, "Failed to find node with node-name='%s'", node_name);
|
|
return NULL;
|
|
}
|
|
|
|
aio_context = bdrv_get_aio_context(to_replace_bs);
|
|
aio_context_acquire(aio_context);
|
|
|
|
if (bdrv_op_is_blocked(to_replace_bs, BLOCK_OP_TYPE_REPLACE, errp)) {
|
|
to_replace_bs = NULL;
|
|
goto out;
|
|
}
|
|
|
|
/* We don't want arbitrary node of the BDS chain to be replaced only the top
|
|
* most non filter in order to prevent data corruption.
|
|
* Another benefit is that this tests exclude backing files which are
|
|
* blocked by the backing blockers.
|
|
*/
|
|
if (!bdrv_recurse_can_replace(parent_bs, to_replace_bs)) {
|
|
error_setg(errp, "Cannot replace '%s' by a node mirrored from '%s', "
|
|
"because it cannot be guaranteed that doing so would not "
|
|
"lead to an abrupt change of visible data",
|
|
node_name, parent_bs->node_name);
|
|
to_replace_bs = NULL;
|
|
goto out;
|
|
}
|
|
|
|
out:
|
|
aio_context_release(aio_context);
|
|
return to_replace_bs;
|
|
}
|
|
|
|
/**
|
|
* Iterates through the list of runtime option keys that are said to
|
|
* be "strong" for a BDS. An option is called "strong" if it changes
|
|
* a BDS's data. For example, the null block driver's "size" and
|
|
* "read-zeroes" options are strong, but its "latency-ns" option is
|
|
* not.
|
|
*
|
|
* If a key returned by this function ends with a dot, all options
|
|
* starting with that prefix are strong.
|
|
*/
|
|
static const char *const *strong_options(BlockDriverState *bs,
|
|
const char *const *curopt)
|
|
{
|
|
static const char *const global_options[] = {
|
|
"driver", "filename", NULL
|
|
};
|
|
|
|
if (!curopt) {
|
|
return &global_options[0];
|
|
}
|
|
|
|
curopt++;
|
|
if (curopt == &global_options[ARRAY_SIZE(global_options) - 1] && bs->drv) {
|
|
curopt = bs->drv->strong_runtime_opts;
|
|
}
|
|
|
|
return (curopt && *curopt) ? curopt : NULL;
|
|
}
|
|
|
|
/**
|
|
* Copies all strong runtime options from bs->options to the given
|
|
* QDict. The set of strong option keys is determined by invoking
|
|
* strong_options().
|
|
*
|
|
* Returns true iff any strong option was present in bs->options (and
|
|
* thus copied to the target QDict) with the exception of "filename"
|
|
* and "driver". The caller is expected to use this value to decide
|
|
* whether the existence of strong options prevents the generation of
|
|
* a plain filename.
|
|
*/
|
|
static bool append_strong_runtime_options(QDict *d, BlockDriverState *bs)
|
|
{
|
|
bool found_any = false;
|
|
const char *const *option_name = NULL;
|
|
|
|
if (!bs->drv) {
|
|
return false;
|
|
}
|
|
|
|
while ((option_name = strong_options(bs, option_name))) {
|
|
bool option_given = false;
|
|
|
|
assert(strlen(*option_name) > 0);
|
|
if ((*option_name)[strlen(*option_name) - 1] != '.') {
|
|
QObject *entry = qdict_get(bs->options, *option_name);
|
|
if (!entry) {
|
|
continue;
|
|
}
|
|
|
|
qdict_put_obj(d, *option_name, qobject_ref(entry));
|
|
option_given = true;
|
|
} else {
|
|
const QDictEntry *entry;
|
|
for (entry = qdict_first(bs->options); entry;
|
|
entry = qdict_next(bs->options, entry))
|
|
{
|
|
if (strstart(qdict_entry_key(entry), *option_name, NULL)) {
|
|
qdict_put_obj(d, qdict_entry_key(entry),
|
|
qobject_ref(qdict_entry_value(entry)));
|
|
option_given = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* While "driver" and "filename" need to be included in a JSON filename,
|
|
* their existence does not prohibit generation of a plain filename. */
|
|
if (!found_any && option_given &&
|
|
strcmp(*option_name, "driver") && strcmp(*option_name, "filename"))
|
|
{
|
|
found_any = true;
|
|
}
|
|
}
|
|
|
|
if (!qdict_haskey(d, "driver")) {
|
|
/* Drivers created with bdrv_new_open_driver() may not have a
|
|
* @driver option. Add it here. */
|
|
qdict_put_str(d, "driver", bs->drv->format_name);
|
|
}
|
|
|
|
return found_any;
|
|
}
|
|
|
|
/* Note: This function may return false positives; it may return true
|
|
* even if opening the backing file specified by bs's image header
|
|
* would result in exactly bs->backing. */
|
|
bool bdrv_backing_overridden(BlockDriverState *bs)
|
|
{
|
|
if (bs->backing) {
|
|
return strcmp(bs->auto_backing_file,
|
|
bs->backing->bs->filename);
|
|
} else {
|
|
/* No backing BDS, so if the image header reports any backing
|
|
* file, it must have been suppressed */
|
|
return bs->auto_backing_file[0] != '\0';
|
|
}
|
|
}
|
|
|
|
/* Updates the following BDS fields:
|
|
* - exact_filename: A filename which may be used for opening a block device
|
|
* which (mostly) equals the given BDS (even without any
|
|
* other options; so reading and writing must return the same
|
|
* results, but caching etc. may be different)
|
|
* - full_open_options: Options which, when given when opening a block device
|
|
* (without a filename), result in a BDS (mostly)
|
|
* equalling the given one
|
|
* - filename: If exact_filename is set, it is copied here. Otherwise,
|
|
* full_open_options is converted to a JSON object, prefixed with
|
|
* "json:" (for use through the JSON pseudo protocol) and put here.
|
|
*/
|
|
void bdrv_refresh_filename(BlockDriverState *bs)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
BdrvChild *child;
|
|
BlockDriverState *primary_child_bs;
|
|
QDict *opts;
|
|
bool backing_overridden;
|
|
bool generate_json_filename; /* Whether our default implementation should
|
|
fill exact_filename (false) or not (true) */
|
|
|
|
if (!drv) {
|
|
return;
|
|
}
|
|
|
|
/* This BDS's file name may depend on any of its children's file names, so
|
|
* refresh those first */
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
bdrv_refresh_filename(child->bs);
|
|
}
|
|
|
|
if (bs->implicit) {
|
|
/* For implicit nodes, just copy everything from the single child */
|
|
child = QLIST_FIRST(&bs->children);
|
|
assert(QLIST_NEXT(child, next) == NULL);
|
|
|
|
pstrcpy(bs->exact_filename, sizeof(bs->exact_filename),
|
|
child->bs->exact_filename);
|
|
pstrcpy(bs->filename, sizeof(bs->filename), child->bs->filename);
|
|
|
|
qobject_unref(bs->full_open_options);
|
|
bs->full_open_options = qobject_ref(child->bs->full_open_options);
|
|
|
|
return;
|
|
}
|
|
|
|
backing_overridden = bdrv_backing_overridden(bs);
|
|
|
|
if (bs->open_flags & BDRV_O_NO_IO) {
|
|
/* Without I/O, the backing file does not change anything.
|
|
* Therefore, in such a case (primarily qemu-img), we can
|
|
* pretend the backing file has not been overridden even if
|
|
* it technically has been. */
|
|
backing_overridden = false;
|
|
}
|
|
|
|
/* Gather the options QDict */
|
|
opts = qdict_new();
|
|
generate_json_filename = append_strong_runtime_options(opts, bs);
|
|
generate_json_filename |= backing_overridden;
|
|
|
|
if (drv->bdrv_gather_child_options) {
|
|
/* Some block drivers may not want to present all of their children's
|
|
* options, or name them differently from BdrvChild.name */
|
|
drv->bdrv_gather_child_options(bs, opts, backing_overridden);
|
|
} else {
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
if (child == bs->backing && !backing_overridden) {
|
|
/* We can skip the backing BDS if it has not been overridden */
|
|
continue;
|
|
}
|
|
|
|
qdict_put(opts, child->name,
|
|
qobject_ref(child->bs->full_open_options));
|
|
}
|
|
|
|
if (backing_overridden && !bs->backing) {
|
|
/* Force no backing file */
|
|
qdict_put_null(opts, "backing");
|
|
}
|
|
}
|
|
|
|
qobject_unref(bs->full_open_options);
|
|
bs->full_open_options = opts;
|
|
|
|
primary_child_bs = bdrv_primary_bs(bs);
|
|
|
|
if (drv->bdrv_refresh_filename) {
|
|
/* Obsolete information is of no use here, so drop the old file name
|
|
* information before refreshing it */
|
|
bs->exact_filename[0] = '\0';
|
|
|
|
drv->bdrv_refresh_filename(bs);
|
|
} else if (primary_child_bs) {
|
|
/*
|
|
* Try to reconstruct valid information from the underlying
|
|
* file -- this only works for format nodes (filter nodes
|
|
* cannot be probed and as such must be selected by the user
|
|
* either through an options dict, or through a special
|
|
* filename which the filter driver must construct in its
|
|
* .bdrv_refresh_filename() implementation).
|
|
*/
|
|
|
|
bs->exact_filename[0] = '\0';
|
|
|
|
/*
|
|
* We can use the underlying file's filename if:
|
|
* - it has a filename,
|
|
* - the current BDS is not a filter,
|
|
* - the file is a protocol BDS, and
|
|
* - opening that file (as this BDS's format) will automatically create
|
|
* the BDS tree we have right now, that is:
|
|
* - the user did not significantly change this BDS's behavior with
|
|
* some explicit (strong) options
|
|
* - no non-file child of this BDS has been overridden by the user
|
|
* Both of these conditions are represented by generate_json_filename.
|
|
*/
|
|
if (primary_child_bs->exact_filename[0] &&
|
|
primary_child_bs->drv->bdrv_file_open &&
|
|
!drv->is_filter && !generate_json_filename)
|
|
{
|
|
strcpy(bs->exact_filename, primary_child_bs->exact_filename);
|
|
}
|
|
}
|
|
|
|
if (bs->exact_filename[0]) {
|
|
pstrcpy(bs->filename, sizeof(bs->filename), bs->exact_filename);
|
|
} else {
|
|
GString *json = qobject_to_json(QOBJECT(bs->full_open_options));
|
|
if (snprintf(bs->filename, sizeof(bs->filename), "json:%s",
|
|
json->str) >= sizeof(bs->filename)) {
|
|
/* Give user a hint if we truncated things. */
|
|
strcpy(bs->filename + sizeof(bs->filename) - 4, "...");
|
|
}
|
|
g_string_free(json, true);
|
|
}
|
|
}
|
|
|
|
char *bdrv_dirname(BlockDriverState *bs, Error **errp)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
BlockDriverState *child_bs;
|
|
|
|
if (!drv) {
|
|
error_setg(errp, "Node '%s' is ejected", bs->node_name);
|
|
return NULL;
|
|
}
|
|
|
|
if (drv->bdrv_dirname) {
|
|
return drv->bdrv_dirname(bs, errp);
|
|
}
|
|
|
|
child_bs = bdrv_primary_bs(bs);
|
|
if (child_bs) {
|
|
return bdrv_dirname(child_bs, errp);
|
|
}
|
|
|
|
bdrv_refresh_filename(bs);
|
|
if (bs->exact_filename[0] != '\0') {
|
|
return path_combine(bs->exact_filename, "");
|
|
}
|
|
|
|
error_setg(errp, "Cannot generate a base directory for %s nodes",
|
|
drv->format_name);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Hot add/remove a BDS's child. So the user can take a child offline when
|
|
* it is broken and take a new child online
|
|
*/
|
|
void bdrv_add_child(BlockDriverState *parent_bs, BlockDriverState *child_bs,
|
|
Error **errp)
|
|
{
|
|
|
|
if (!parent_bs->drv || !parent_bs->drv->bdrv_add_child) {
|
|
error_setg(errp, "The node %s does not support adding a child",
|
|
bdrv_get_device_or_node_name(parent_bs));
|
|
return;
|
|
}
|
|
|
|
if (!QLIST_EMPTY(&child_bs->parents)) {
|
|
error_setg(errp, "The node %s already has a parent",
|
|
child_bs->node_name);
|
|
return;
|
|
}
|
|
|
|
parent_bs->drv->bdrv_add_child(parent_bs, child_bs, errp);
|
|
}
|
|
|
|
void bdrv_del_child(BlockDriverState *parent_bs, BdrvChild *child, Error **errp)
|
|
{
|
|
BdrvChild *tmp;
|
|
|
|
if (!parent_bs->drv || !parent_bs->drv->bdrv_del_child) {
|
|
error_setg(errp, "The node %s does not support removing a child",
|
|
bdrv_get_device_or_node_name(parent_bs));
|
|
return;
|
|
}
|
|
|
|
QLIST_FOREACH(tmp, &parent_bs->children, next) {
|
|
if (tmp == child) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!tmp) {
|
|
error_setg(errp, "The node %s does not have a child named %s",
|
|
bdrv_get_device_or_node_name(parent_bs),
|
|
bdrv_get_device_or_node_name(child->bs));
|
|
return;
|
|
}
|
|
|
|
parent_bs->drv->bdrv_del_child(parent_bs, child, errp);
|
|
}
|
|
|
|
int bdrv_make_empty(BdrvChild *c, Error **errp)
|
|
{
|
|
BlockDriver *drv = c->bs->drv;
|
|
int ret;
|
|
|
|
assert(c->perm & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED));
|
|
|
|
if (!drv->bdrv_make_empty) {
|
|
error_setg(errp, "%s does not support emptying nodes",
|
|
drv->format_name);
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
ret = drv->bdrv_make_empty(c->bs);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "Failed to empty %s",
|
|
c->bs->filename);
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Return the child that @bs acts as an overlay for, and from which data may be
|
|
* copied in COW or COR operations. Usually this is the backing file.
|
|
*/
|
|
BdrvChild *bdrv_cow_child(BlockDriverState *bs)
|
|
{
|
|
if (!bs || !bs->drv) {
|
|
return NULL;
|
|
}
|
|
|
|
if (bs->drv->is_filter) {
|
|
return NULL;
|
|
}
|
|
|
|
if (!bs->backing) {
|
|
return NULL;
|
|
}
|
|
|
|
assert(bs->backing->role & BDRV_CHILD_COW);
|
|
return bs->backing;
|
|
}
|
|
|
|
/*
|
|
* If @bs acts as a filter for exactly one of its children, return
|
|
* that child.
|
|
*/
|
|
BdrvChild *bdrv_filter_child(BlockDriverState *bs)
|
|
{
|
|
BdrvChild *c;
|
|
|
|
if (!bs || !bs->drv) {
|
|
return NULL;
|
|
}
|
|
|
|
if (!bs->drv->is_filter) {
|
|
return NULL;
|
|
}
|
|
|
|
/* Only one of @backing or @file may be used */
|
|
assert(!(bs->backing && bs->file));
|
|
|
|
c = bs->backing ?: bs->file;
|
|
if (!c) {
|
|
return NULL;
|
|
}
|
|
|
|
assert(c->role & BDRV_CHILD_FILTERED);
|
|
return c;
|
|
}
|
|
|
|
/*
|
|
* Return either the result of bdrv_cow_child() or bdrv_filter_child(),
|
|
* whichever is non-NULL.
|
|
*
|
|
* Return NULL if both are NULL.
|
|
*/
|
|
BdrvChild *bdrv_filter_or_cow_child(BlockDriverState *bs)
|
|
{
|
|
BdrvChild *cow_child = bdrv_cow_child(bs);
|
|
BdrvChild *filter_child = bdrv_filter_child(bs);
|
|
|
|
/* Filter nodes cannot have COW backing files */
|
|
assert(!(cow_child && filter_child));
|
|
|
|
return cow_child ?: filter_child;
|
|
}
|
|
|
|
/*
|
|
* Return the primary child of this node: For filters, that is the
|
|
* filtered child. For other nodes, that is usually the child storing
|
|
* metadata.
|
|
* (A generally more helpful description is that this is (usually) the
|
|
* child that has the same filename as @bs.)
|
|
*
|
|
* Drivers do not necessarily have a primary child; for example quorum
|
|
* does not.
|
|
*/
|
|
BdrvChild *bdrv_primary_child(BlockDriverState *bs)
|
|
{
|
|
BdrvChild *c, *found = NULL;
|
|
|
|
QLIST_FOREACH(c, &bs->children, next) {
|
|
if (c->role & BDRV_CHILD_PRIMARY) {
|
|
assert(!found);
|
|
found = c;
|
|
}
|
|
}
|
|
|
|
return found;
|
|
}
|
|
|
|
static BlockDriverState *bdrv_do_skip_filters(BlockDriverState *bs,
|
|
bool stop_on_explicit_filter)
|
|
{
|
|
BdrvChild *c;
|
|
|
|
if (!bs) {
|
|
return NULL;
|
|
}
|
|
|
|
while (!(stop_on_explicit_filter && !bs->implicit)) {
|
|
c = bdrv_filter_child(bs);
|
|
if (!c) {
|
|
/*
|
|
* A filter that is embedded in a working block graph must
|
|
* have a child. Assert this here so this function does
|
|
* not return a filter node that is not expected by the
|
|
* caller.
|
|
*/
|
|
assert(!bs->drv || !bs->drv->is_filter);
|
|
break;
|
|
}
|
|
bs = c->bs;
|
|
}
|
|
/*
|
|
* Note that this treats nodes with bs->drv == NULL as not being
|
|
* filters (bs->drv == NULL should be replaced by something else
|
|
* anyway).
|
|
* The advantage of this behavior is that this function will thus
|
|
* always return a non-NULL value (given a non-NULL @bs).
|
|
*/
|
|
|
|
return bs;
|
|
}
|
|
|
|
/*
|
|
* Return the first BDS that has not been added implicitly or that
|
|
* does not have a filtered child down the chain starting from @bs
|
|
* (including @bs itself).
|
|
*/
|
|
BlockDriverState *bdrv_skip_implicit_filters(BlockDriverState *bs)
|
|
{
|
|
return bdrv_do_skip_filters(bs, true);
|
|
}
|
|
|
|
/*
|
|
* Return the first BDS that does not have a filtered child down the
|
|
* chain starting from @bs (including @bs itself).
|
|
*/
|
|
BlockDriverState *bdrv_skip_filters(BlockDriverState *bs)
|
|
{
|
|
return bdrv_do_skip_filters(bs, false);
|
|
}
|
|
|
|
/*
|
|
* For a backing chain, return the first non-filter backing image of
|
|
* the first non-filter image.
|
|
*/
|
|
BlockDriverState *bdrv_backing_chain_next(BlockDriverState *bs)
|
|
{
|
|
return bdrv_skip_filters(bdrv_cow_bs(bdrv_skip_filters(bs)));
|
|
}
|