741cc43133
The NBD code uses the BDS close notifier to determine when a medium is ejected. However, now it should use the BB's BDS removal notifier for that instead of the BDS's close notifier. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
1127 lines
28 KiB
C
1127 lines
28 KiB
C
/*
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* Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
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*
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* Network Block Device Server Side
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; under version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
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#include "nbd-internal.h"
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static int system_errno_to_nbd_errno(int err)
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{
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switch (err) {
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case 0:
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return NBD_SUCCESS;
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case EPERM:
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return NBD_EPERM;
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case EIO:
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return NBD_EIO;
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case ENOMEM:
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return NBD_ENOMEM;
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#ifdef EDQUOT
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case EDQUOT:
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#endif
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case EFBIG:
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case ENOSPC:
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return NBD_ENOSPC;
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case EINVAL:
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default:
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return NBD_EINVAL;
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}
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}
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/* Definitions for opaque data types */
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typedef struct NBDRequest NBDRequest;
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struct NBDRequest {
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QSIMPLEQ_ENTRY(NBDRequest) entry;
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NBDClient *client;
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uint8_t *data;
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};
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struct NBDExport {
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int refcount;
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void (*close)(NBDExport *exp);
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BlockBackend *blk;
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char *name;
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off_t dev_offset;
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off_t size;
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uint32_t nbdflags;
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QTAILQ_HEAD(, NBDClient) clients;
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QTAILQ_ENTRY(NBDExport) next;
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AioContext *ctx;
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Notifier eject_notifier;
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};
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static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports);
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struct NBDClient {
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int refcount;
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void (*close)(NBDClient *client);
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NBDExport *exp;
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int sock;
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Coroutine *recv_coroutine;
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CoMutex send_lock;
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Coroutine *send_coroutine;
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bool can_read;
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QTAILQ_ENTRY(NBDClient) next;
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int nb_requests;
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bool closing;
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};
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/* That's all folks */
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static void nbd_set_handlers(NBDClient *client);
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static void nbd_unset_handlers(NBDClient *client);
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static void nbd_update_can_read(NBDClient *client);
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static void nbd_negotiate_continue(void *opaque)
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{
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qemu_coroutine_enter(opaque, NULL);
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}
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static ssize_t nbd_negotiate_read(int fd, void *buffer, size_t size)
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{
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ssize_t ret;
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assert(qemu_in_coroutine());
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/* Negotiation are always in main loop. */
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qemu_set_fd_handler(fd, nbd_negotiate_continue, NULL,
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qemu_coroutine_self());
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ret = read_sync(fd, buffer, size);
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qemu_set_fd_handler(fd, NULL, NULL, NULL);
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return ret;
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}
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static ssize_t nbd_negotiate_write(int fd, void *buffer, size_t size)
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{
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ssize_t ret;
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assert(qemu_in_coroutine());
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/* Negotiation are always in main loop. */
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qemu_set_fd_handler(fd, NULL, nbd_negotiate_continue,
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qemu_coroutine_self());
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ret = write_sync(fd, buffer, size);
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qemu_set_fd_handler(fd, NULL, NULL, NULL);
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return ret;
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}
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static ssize_t nbd_negotiate_drop_sync(int fd, size_t size)
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{
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ssize_t ret, dropped = size;
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uint8_t *buffer = g_malloc(MIN(65536, size));
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while (size > 0) {
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ret = nbd_negotiate_read(fd, buffer, MIN(65536, size));
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if (ret < 0) {
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g_free(buffer);
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return ret;
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}
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assert(ret <= size);
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size -= ret;
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}
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g_free(buffer);
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return dropped;
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}
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/* Basic flow for negotiation
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Server Client
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Negotiate
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or
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Server Client
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Negotiate #1
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Option
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Negotiate #2
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----
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followed by
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Server Client
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Request
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Response
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Request
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Response
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...
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...
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Request (type == 2)
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*/
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static int nbd_negotiate_send_rep(int csock, uint32_t type, uint32_t opt)
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{
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uint64_t magic;
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uint32_t len;
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magic = cpu_to_be64(NBD_REP_MAGIC);
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if (nbd_negotiate_write(csock, &magic, sizeof(magic)) != sizeof(magic)) {
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LOG("write failed (rep magic)");
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return -EINVAL;
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}
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opt = cpu_to_be32(opt);
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if (nbd_negotiate_write(csock, &opt, sizeof(opt)) != sizeof(opt)) {
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LOG("write failed (rep opt)");
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return -EINVAL;
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}
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type = cpu_to_be32(type);
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if (nbd_negotiate_write(csock, &type, sizeof(type)) != sizeof(type)) {
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LOG("write failed (rep type)");
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return -EINVAL;
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}
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len = cpu_to_be32(0);
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if (nbd_negotiate_write(csock, &len, sizeof(len)) != sizeof(len)) {
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LOG("write failed (rep data length)");
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return -EINVAL;
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}
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return 0;
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}
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static int nbd_negotiate_send_rep_list(int csock, NBDExport *exp)
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{
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uint64_t magic, name_len;
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uint32_t opt, type, len;
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name_len = strlen(exp->name);
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magic = cpu_to_be64(NBD_REP_MAGIC);
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if (nbd_negotiate_write(csock, &magic, sizeof(magic)) != sizeof(magic)) {
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LOG("write failed (magic)");
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return -EINVAL;
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}
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opt = cpu_to_be32(NBD_OPT_LIST);
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if (nbd_negotiate_write(csock, &opt, sizeof(opt)) != sizeof(opt)) {
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LOG("write failed (opt)");
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return -EINVAL;
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}
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type = cpu_to_be32(NBD_REP_SERVER);
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if (nbd_negotiate_write(csock, &type, sizeof(type)) != sizeof(type)) {
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LOG("write failed (reply type)");
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return -EINVAL;
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}
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len = cpu_to_be32(name_len + sizeof(len));
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if (nbd_negotiate_write(csock, &len, sizeof(len)) != sizeof(len)) {
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LOG("write failed (length)");
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return -EINVAL;
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}
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len = cpu_to_be32(name_len);
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if (nbd_negotiate_write(csock, &len, sizeof(len)) != sizeof(len)) {
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LOG("write failed (length)");
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return -EINVAL;
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}
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if (nbd_negotiate_write(csock, exp->name, name_len) != name_len) {
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LOG("write failed (buffer)");
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return -EINVAL;
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}
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return 0;
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}
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static int nbd_negotiate_handle_list(NBDClient *client, uint32_t length)
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{
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int csock;
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NBDExport *exp;
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csock = client->sock;
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if (length) {
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if (nbd_negotiate_drop_sync(csock, length) != length) {
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return -EIO;
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}
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return nbd_negotiate_send_rep(csock, NBD_REP_ERR_INVALID, NBD_OPT_LIST);
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}
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/* For each export, send a NBD_REP_SERVER reply. */
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QTAILQ_FOREACH(exp, &exports, next) {
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if (nbd_negotiate_send_rep_list(csock, exp)) {
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return -EINVAL;
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}
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}
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/* Finish with a NBD_REP_ACK. */
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return nbd_negotiate_send_rep(csock, NBD_REP_ACK, NBD_OPT_LIST);
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}
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static int nbd_negotiate_handle_export_name(NBDClient *client, uint32_t length)
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{
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int rc = -EINVAL, csock = client->sock;
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char name[256];
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/* Client sends:
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[20 .. xx] export name (length bytes)
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*/
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TRACE("Checking length");
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if (length > 255) {
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LOG("Bad length received");
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goto fail;
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}
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if (nbd_negotiate_read(csock, name, length) != length) {
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LOG("read failed");
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goto fail;
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}
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name[length] = '\0';
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client->exp = nbd_export_find(name);
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if (!client->exp) {
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LOG("export not found");
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goto fail;
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}
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QTAILQ_INSERT_TAIL(&client->exp->clients, client, next);
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nbd_export_get(client->exp);
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rc = 0;
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fail:
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return rc;
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}
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static int nbd_negotiate_options(NBDClient *client)
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{
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int csock = client->sock;
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uint32_t flags;
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/* Client sends:
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[ 0 .. 3] client flags
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[ 0 .. 7] NBD_OPTS_MAGIC
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[ 8 .. 11] NBD option
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[12 .. 15] Data length
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... Rest of request
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[ 0 .. 7] NBD_OPTS_MAGIC
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[ 8 .. 11] Second NBD option
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[12 .. 15] Data length
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... Rest of request
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*/
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if (nbd_negotiate_read(csock, &flags, sizeof(flags)) != sizeof(flags)) {
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LOG("read failed");
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return -EIO;
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}
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TRACE("Checking client flags");
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be32_to_cpus(&flags);
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if (flags != 0 && flags != NBD_FLAG_C_FIXED_NEWSTYLE) {
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LOG("Bad client flags received");
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return -EIO;
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}
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while (1) {
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int ret;
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uint32_t tmp, length;
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uint64_t magic;
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if (nbd_negotiate_read(csock, &magic, sizeof(magic)) != sizeof(magic)) {
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LOG("read failed");
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return -EINVAL;
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}
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TRACE("Checking opts magic");
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if (magic != be64_to_cpu(NBD_OPTS_MAGIC)) {
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LOG("Bad magic received");
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return -EINVAL;
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}
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if (nbd_negotiate_read(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
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LOG("read failed");
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return -EINVAL;
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}
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if (nbd_negotiate_read(csock, &length,
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sizeof(length)) != sizeof(length)) {
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LOG("read failed");
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return -EINVAL;
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}
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length = be32_to_cpu(length);
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TRACE("Checking option");
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switch (be32_to_cpu(tmp)) {
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case NBD_OPT_LIST:
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ret = nbd_negotiate_handle_list(client, length);
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if (ret < 0) {
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return ret;
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}
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break;
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case NBD_OPT_ABORT:
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return -EINVAL;
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case NBD_OPT_EXPORT_NAME:
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return nbd_negotiate_handle_export_name(client, length);
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default:
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tmp = be32_to_cpu(tmp);
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LOG("Unsupported option 0x%x", tmp);
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nbd_negotiate_send_rep(client->sock, NBD_REP_ERR_UNSUP, tmp);
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return -EINVAL;
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}
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}
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}
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typedef struct {
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NBDClient *client;
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Coroutine *co;
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} NBDClientNewData;
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static coroutine_fn int nbd_negotiate(NBDClientNewData *data)
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{
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NBDClient *client = data->client;
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int csock = client->sock;
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char buf[8 + 8 + 8 + 128];
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int rc;
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const int myflags = (NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_TRIM |
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NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA);
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/* Negotiation header without options:
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[ 0 .. 7] passwd ("NBDMAGIC")
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[ 8 .. 15] magic (NBD_CLIENT_MAGIC)
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[16 .. 23] size
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[24 .. 25] server flags (0)
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[26 .. 27] export flags
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[28 .. 151] reserved (0)
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|
|
|
Negotiation header with options, part 1:
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[ 0 .. 7] passwd ("NBDMAGIC")
|
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[ 8 .. 15] magic (NBD_OPTS_MAGIC)
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[16 .. 17] server flags (0)
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part 2 (after options are sent):
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[18 .. 25] size
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[26 .. 27] export flags
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[28 .. 151] reserved (0)
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*/
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rc = -EINVAL;
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TRACE("Beginning negotiation.");
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memset(buf, 0, sizeof(buf));
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memcpy(buf, "NBDMAGIC", 8);
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if (client->exp) {
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assert ((client->exp->nbdflags & ~65535) == 0);
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cpu_to_be64w((uint64_t*)(buf + 8), NBD_CLIENT_MAGIC);
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cpu_to_be64w((uint64_t*)(buf + 16), client->exp->size);
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cpu_to_be16w((uint16_t*)(buf + 26), client->exp->nbdflags | myflags);
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} else {
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cpu_to_be64w((uint64_t*)(buf + 8), NBD_OPTS_MAGIC);
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cpu_to_be16w((uint16_t *)(buf + 16), NBD_FLAG_FIXED_NEWSTYLE);
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}
|
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|
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if (client->exp) {
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if (nbd_negotiate_write(csock, buf, sizeof(buf)) != sizeof(buf)) {
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LOG("write failed");
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goto fail;
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}
|
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} else {
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if (nbd_negotiate_write(csock, buf, 18) != 18) {
|
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LOG("write failed");
|
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goto fail;
|
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}
|
|
rc = nbd_negotiate_options(client);
|
|
if (rc != 0) {
|
|
LOG("option negotiation failed");
|
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goto fail;
|
|
}
|
|
|
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assert ((client->exp->nbdflags & ~65535) == 0);
|
|
cpu_to_be64w((uint64_t*)(buf + 18), client->exp->size);
|
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cpu_to_be16w((uint16_t*)(buf + 26), client->exp->nbdflags | myflags);
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if (nbd_negotiate_write(csock, buf + 18,
|
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sizeof(buf) - 18) != sizeof(buf) - 18) {
|
|
LOG("write failed");
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
TRACE("Negotiation succeeded.");
|
|
rc = 0;
|
|
fail:
|
|
return rc;
|
|
}
|
|
|
|
#ifdef __linux__
|
|
|
|
int nbd_disconnect(int fd)
|
|
{
|
|
ioctl(fd, NBD_CLEAR_QUE);
|
|
ioctl(fd, NBD_DISCONNECT);
|
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ioctl(fd, NBD_CLEAR_SOCK);
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return 0;
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|
}
|
|
|
|
#else
|
|
|
|
int nbd_disconnect(int fd)
|
|
{
|
|
return -ENOTSUP;
|
|
}
|
|
#endif
|
|
|
|
static ssize_t nbd_receive_request(int csock, struct nbd_request *request)
|
|
{
|
|
uint8_t buf[NBD_REQUEST_SIZE];
|
|
uint32_t magic;
|
|
ssize_t ret;
|
|
|
|
ret = read_sync(csock, buf, sizeof(buf));
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
if (ret != sizeof(buf)) {
|
|
LOG("read failed");
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Request
|
|
[ 0 .. 3] magic (NBD_REQUEST_MAGIC)
|
|
[ 4 .. 7] type (0 == READ, 1 == WRITE)
|
|
[ 8 .. 15] handle
|
|
[16 .. 23] from
|
|
[24 .. 27] len
|
|
*/
|
|
|
|
magic = be32_to_cpup((uint32_t*)buf);
|
|
request->type = be32_to_cpup((uint32_t*)(buf + 4));
|
|
request->handle = be64_to_cpup((uint64_t*)(buf + 8));
|
|
request->from = be64_to_cpup((uint64_t*)(buf + 16));
|
|
request->len = be32_to_cpup((uint32_t*)(buf + 24));
|
|
|
|
TRACE("Got request: "
|
|
"{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }",
|
|
magic, request->type, request->from, request->len);
|
|
|
|
if (magic != NBD_REQUEST_MAGIC) {
|
|
LOG("invalid magic (got 0x%x)", magic);
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t nbd_send_reply(int csock, struct nbd_reply *reply)
|
|
{
|
|
uint8_t buf[NBD_REPLY_SIZE];
|
|
ssize_t ret;
|
|
|
|
reply->error = system_errno_to_nbd_errno(reply->error);
|
|
|
|
/* Reply
|
|
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
|
|
[ 4 .. 7] error (0 == no error)
|
|
[ 7 .. 15] handle
|
|
*/
|
|
cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC);
|
|
cpu_to_be32w((uint32_t*)(buf + 4), reply->error);
|
|
cpu_to_be64w((uint64_t*)(buf + 8), reply->handle);
|
|
|
|
TRACE("Sending response to client");
|
|
|
|
ret = write_sync(csock, buf, sizeof(buf));
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
if (ret != sizeof(buf)) {
|
|
LOG("writing to socket failed");
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#define MAX_NBD_REQUESTS 16
|
|
|
|
void nbd_client_get(NBDClient *client)
|
|
{
|
|
client->refcount++;
|
|
}
|
|
|
|
void nbd_client_put(NBDClient *client)
|
|
{
|
|
if (--client->refcount == 0) {
|
|
/* The last reference should be dropped by client->close,
|
|
* which is called by client_close.
|
|
*/
|
|
assert(client->closing);
|
|
|
|
nbd_unset_handlers(client);
|
|
close(client->sock);
|
|
client->sock = -1;
|
|
if (client->exp) {
|
|
QTAILQ_REMOVE(&client->exp->clients, client, next);
|
|
nbd_export_put(client->exp);
|
|
}
|
|
g_free(client);
|
|
}
|
|
}
|
|
|
|
static void client_close(NBDClient *client)
|
|
{
|
|
if (client->closing) {
|
|
return;
|
|
}
|
|
|
|
client->closing = true;
|
|
|
|
/* Force requests to finish. They will drop their own references,
|
|
* then we'll close the socket and free the NBDClient.
|
|
*/
|
|
shutdown(client->sock, 2);
|
|
|
|
/* Also tell the client, so that they release their reference. */
|
|
if (client->close) {
|
|
client->close(client);
|
|
}
|
|
}
|
|
|
|
static NBDRequest *nbd_request_get(NBDClient *client)
|
|
{
|
|
NBDRequest *req;
|
|
|
|
assert(client->nb_requests <= MAX_NBD_REQUESTS - 1);
|
|
client->nb_requests++;
|
|
nbd_update_can_read(client);
|
|
|
|
req = g_new0(NBDRequest, 1);
|
|
nbd_client_get(client);
|
|
req->client = client;
|
|
return req;
|
|
}
|
|
|
|
static void nbd_request_put(NBDRequest *req)
|
|
{
|
|
NBDClient *client = req->client;
|
|
|
|
if (req->data) {
|
|
qemu_vfree(req->data);
|
|
}
|
|
g_free(req);
|
|
|
|
client->nb_requests--;
|
|
nbd_update_can_read(client);
|
|
nbd_client_put(client);
|
|
}
|
|
|
|
static void blk_aio_attached(AioContext *ctx, void *opaque)
|
|
{
|
|
NBDExport *exp = opaque;
|
|
NBDClient *client;
|
|
|
|
TRACE("Export %s: Attaching clients to AIO context %p\n", exp->name, ctx);
|
|
|
|
exp->ctx = ctx;
|
|
|
|
QTAILQ_FOREACH(client, &exp->clients, next) {
|
|
nbd_set_handlers(client);
|
|
}
|
|
}
|
|
|
|
static void blk_aio_detach(void *opaque)
|
|
{
|
|
NBDExport *exp = opaque;
|
|
NBDClient *client;
|
|
|
|
TRACE("Export %s: Detaching clients from AIO context %p\n", exp->name, exp->ctx);
|
|
|
|
QTAILQ_FOREACH(client, &exp->clients, next) {
|
|
nbd_unset_handlers(client);
|
|
}
|
|
|
|
exp->ctx = NULL;
|
|
}
|
|
|
|
static void nbd_eject_notifier(Notifier *n, void *data)
|
|
{
|
|
NBDExport *exp = container_of(n, NBDExport, eject_notifier);
|
|
nbd_export_close(exp);
|
|
}
|
|
|
|
NBDExport *nbd_export_new(BlockBackend *blk, off_t dev_offset, off_t size,
|
|
uint32_t nbdflags, void (*close)(NBDExport *),
|
|
Error **errp)
|
|
{
|
|
NBDExport *exp = g_malloc0(sizeof(NBDExport));
|
|
exp->refcount = 1;
|
|
QTAILQ_INIT(&exp->clients);
|
|
exp->blk = blk;
|
|
exp->dev_offset = dev_offset;
|
|
exp->nbdflags = nbdflags;
|
|
exp->size = size < 0 ? blk_getlength(blk) : size;
|
|
if (exp->size < 0) {
|
|
error_setg_errno(errp, -exp->size,
|
|
"Failed to determine the NBD export's length");
|
|
goto fail;
|
|
}
|
|
exp->size -= exp->size % BDRV_SECTOR_SIZE;
|
|
|
|
exp->close = close;
|
|
exp->ctx = blk_get_aio_context(blk);
|
|
blk_ref(blk);
|
|
blk_add_aio_context_notifier(blk, blk_aio_attached, blk_aio_detach, exp);
|
|
|
|
exp->eject_notifier.notify = nbd_eject_notifier;
|
|
blk_add_remove_bs_notifier(blk, &exp->eject_notifier);
|
|
|
|
/*
|
|
* NBD exports are used for non-shared storage migration. Make sure
|
|
* that BDRV_O_INACTIVE is cleared and the image is ready for write
|
|
* access since the export could be available before migration handover.
|
|
*/
|
|
aio_context_acquire(exp->ctx);
|
|
blk_invalidate_cache(blk, NULL);
|
|
aio_context_release(exp->ctx);
|
|
return exp;
|
|
|
|
fail:
|
|
g_free(exp);
|
|
return NULL;
|
|
}
|
|
|
|
NBDExport *nbd_export_find(const char *name)
|
|
{
|
|
NBDExport *exp;
|
|
QTAILQ_FOREACH(exp, &exports, next) {
|
|
if (strcmp(name, exp->name) == 0) {
|
|
return exp;
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
void nbd_export_set_name(NBDExport *exp, const char *name)
|
|
{
|
|
if (exp->name == name) {
|
|
return;
|
|
}
|
|
|
|
nbd_export_get(exp);
|
|
if (exp->name != NULL) {
|
|
g_free(exp->name);
|
|
exp->name = NULL;
|
|
QTAILQ_REMOVE(&exports, exp, next);
|
|
nbd_export_put(exp);
|
|
}
|
|
if (name != NULL) {
|
|
nbd_export_get(exp);
|
|
exp->name = g_strdup(name);
|
|
QTAILQ_INSERT_TAIL(&exports, exp, next);
|
|
}
|
|
nbd_export_put(exp);
|
|
}
|
|
|
|
void nbd_export_close(NBDExport *exp)
|
|
{
|
|
NBDClient *client, *next;
|
|
|
|
nbd_export_get(exp);
|
|
QTAILQ_FOREACH_SAFE(client, &exp->clients, next, next) {
|
|
client_close(client);
|
|
}
|
|
nbd_export_set_name(exp, NULL);
|
|
nbd_export_put(exp);
|
|
}
|
|
|
|
void nbd_export_get(NBDExport *exp)
|
|
{
|
|
assert(exp->refcount > 0);
|
|
exp->refcount++;
|
|
}
|
|
|
|
void nbd_export_put(NBDExport *exp)
|
|
{
|
|
assert(exp->refcount > 0);
|
|
if (exp->refcount == 1) {
|
|
nbd_export_close(exp);
|
|
}
|
|
|
|
if (--exp->refcount == 0) {
|
|
assert(exp->name == NULL);
|
|
|
|
if (exp->close) {
|
|
exp->close(exp);
|
|
}
|
|
|
|
if (exp->blk) {
|
|
notifier_remove(&exp->eject_notifier);
|
|
blk_remove_aio_context_notifier(exp->blk, blk_aio_attached,
|
|
blk_aio_detach, exp);
|
|
blk_unref(exp->blk);
|
|
exp->blk = NULL;
|
|
}
|
|
|
|
g_free(exp);
|
|
}
|
|
}
|
|
|
|
BlockBackend *nbd_export_get_blockdev(NBDExport *exp)
|
|
{
|
|
return exp->blk;
|
|
}
|
|
|
|
void nbd_export_close_all(void)
|
|
{
|
|
NBDExport *exp, *next;
|
|
|
|
QTAILQ_FOREACH_SAFE(exp, &exports, next, next) {
|
|
nbd_export_close(exp);
|
|
}
|
|
}
|
|
|
|
static ssize_t nbd_co_send_reply(NBDRequest *req, struct nbd_reply *reply,
|
|
int len)
|
|
{
|
|
NBDClient *client = req->client;
|
|
int csock = client->sock;
|
|
ssize_t rc, ret;
|
|
|
|
qemu_co_mutex_lock(&client->send_lock);
|
|
client->send_coroutine = qemu_coroutine_self();
|
|
nbd_set_handlers(client);
|
|
|
|
if (!len) {
|
|
rc = nbd_send_reply(csock, reply);
|
|
} else {
|
|
socket_set_cork(csock, 1);
|
|
rc = nbd_send_reply(csock, reply);
|
|
if (rc >= 0) {
|
|
ret = qemu_co_send(csock, req->data, len);
|
|
if (ret != len) {
|
|
rc = -EIO;
|
|
}
|
|
}
|
|
socket_set_cork(csock, 0);
|
|
}
|
|
|
|
client->send_coroutine = NULL;
|
|
nbd_set_handlers(client);
|
|
qemu_co_mutex_unlock(&client->send_lock);
|
|
return rc;
|
|
}
|
|
|
|
static ssize_t nbd_co_receive_request(NBDRequest *req, struct nbd_request *request)
|
|
{
|
|
NBDClient *client = req->client;
|
|
int csock = client->sock;
|
|
uint32_t command;
|
|
ssize_t rc;
|
|
|
|
client->recv_coroutine = qemu_coroutine_self();
|
|
nbd_update_can_read(client);
|
|
|
|
rc = nbd_receive_request(csock, request);
|
|
if (rc < 0) {
|
|
if (rc != -EAGAIN) {
|
|
rc = -EIO;
|
|
}
|
|
goto out;
|
|
}
|
|
|
|
if ((request->from + request->len) < request->from) {
|
|
LOG("integer overflow detected! "
|
|
"you're probably being attacked");
|
|
rc = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
TRACE("Decoding type");
|
|
|
|
command = request->type & NBD_CMD_MASK_COMMAND;
|
|
if (command == NBD_CMD_READ || command == NBD_CMD_WRITE) {
|
|
if (request->len > NBD_MAX_BUFFER_SIZE) {
|
|
LOG("len (%u) is larger than max len (%u)",
|
|
request->len, NBD_MAX_BUFFER_SIZE);
|
|
rc = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
req->data = blk_try_blockalign(client->exp->blk, request->len);
|
|
if (req->data == NULL) {
|
|
rc = -ENOMEM;
|
|
goto out;
|
|
}
|
|
}
|
|
if (command == NBD_CMD_WRITE) {
|
|
TRACE("Reading %u byte(s)", request->len);
|
|
|
|
if (qemu_co_recv(csock, req->data, request->len) != request->len) {
|
|
LOG("reading from socket failed");
|
|
rc = -EIO;
|
|
goto out;
|
|
}
|
|
}
|
|
rc = 0;
|
|
|
|
out:
|
|
client->recv_coroutine = NULL;
|
|
nbd_update_can_read(client);
|
|
|
|
return rc;
|
|
}
|
|
|
|
static void nbd_trip(void *opaque)
|
|
{
|
|
NBDClient *client = opaque;
|
|
NBDExport *exp = client->exp;
|
|
NBDRequest *req;
|
|
struct nbd_request request;
|
|
struct nbd_reply reply;
|
|
ssize_t ret;
|
|
uint32_t command;
|
|
|
|
TRACE("Reading request.");
|
|
if (client->closing) {
|
|
return;
|
|
}
|
|
|
|
req = nbd_request_get(client);
|
|
ret = nbd_co_receive_request(req, &request);
|
|
if (ret == -EAGAIN) {
|
|
goto done;
|
|
}
|
|
if (ret == -EIO) {
|
|
goto out;
|
|
}
|
|
|
|
reply.handle = request.handle;
|
|
reply.error = 0;
|
|
|
|
if (ret < 0) {
|
|
reply.error = -ret;
|
|
goto error_reply;
|
|
}
|
|
command = request.type & NBD_CMD_MASK_COMMAND;
|
|
if (command != NBD_CMD_DISC && (request.from + request.len) > exp->size) {
|
|
LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64
|
|
", Offset: %" PRIu64 "\n",
|
|
request.from, request.len,
|
|
(uint64_t)exp->size, (uint64_t)exp->dev_offset);
|
|
LOG("requested operation past EOF--bad client?");
|
|
goto invalid_request;
|
|
}
|
|
|
|
if (client->closing) {
|
|
/*
|
|
* The client may be closed when we are blocked in
|
|
* nbd_co_receive_request()
|
|
*/
|
|
goto done;
|
|
}
|
|
|
|
switch (command) {
|
|
case NBD_CMD_READ:
|
|
TRACE("Request type is READ");
|
|
|
|
if (request.type & NBD_CMD_FLAG_FUA) {
|
|
ret = blk_co_flush(exp->blk);
|
|
if (ret < 0) {
|
|
LOG("flush failed");
|
|
reply.error = -ret;
|
|
goto error_reply;
|
|
}
|
|
}
|
|
|
|
ret = blk_read(exp->blk,
|
|
(request.from + exp->dev_offset) / BDRV_SECTOR_SIZE,
|
|
req->data, request.len / BDRV_SECTOR_SIZE);
|
|
if (ret < 0) {
|
|
LOG("reading from file failed");
|
|
reply.error = -ret;
|
|
goto error_reply;
|
|
}
|
|
|
|
TRACE("Read %u byte(s)", request.len);
|
|
if (nbd_co_send_reply(req, &reply, request.len) < 0)
|
|
goto out;
|
|
break;
|
|
case NBD_CMD_WRITE:
|
|
TRACE("Request type is WRITE");
|
|
|
|
if (exp->nbdflags & NBD_FLAG_READ_ONLY) {
|
|
TRACE("Server is read-only, return error");
|
|
reply.error = EROFS;
|
|
goto error_reply;
|
|
}
|
|
|
|
TRACE("Writing to device");
|
|
|
|
ret = blk_write(exp->blk,
|
|
(request.from + exp->dev_offset) / BDRV_SECTOR_SIZE,
|
|
req->data, request.len / BDRV_SECTOR_SIZE);
|
|
if (ret < 0) {
|
|
LOG("writing to file failed");
|
|
reply.error = -ret;
|
|
goto error_reply;
|
|
}
|
|
|
|
if (request.type & NBD_CMD_FLAG_FUA) {
|
|
ret = blk_co_flush(exp->blk);
|
|
if (ret < 0) {
|
|
LOG("flush failed");
|
|
reply.error = -ret;
|
|
goto error_reply;
|
|
}
|
|
}
|
|
|
|
if (nbd_co_send_reply(req, &reply, 0) < 0) {
|
|
goto out;
|
|
}
|
|
break;
|
|
case NBD_CMD_DISC:
|
|
TRACE("Request type is DISCONNECT");
|
|
errno = 0;
|
|
goto out;
|
|
case NBD_CMD_FLUSH:
|
|
TRACE("Request type is FLUSH");
|
|
|
|
ret = blk_co_flush(exp->blk);
|
|
if (ret < 0) {
|
|
LOG("flush failed");
|
|
reply.error = -ret;
|
|
}
|
|
if (nbd_co_send_reply(req, &reply, 0) < 0) {
|
|
goto out;
|
|
}
|
|
break;
|
|
case NBD_CMD_TRIM:
|
|
TRACE("Request type is TRIM");
|
|
ret = blk_co_discard(exp->blk, (request.from + exp->dev_offset)
|
|
/ BDRV_SECTOR_SIZE,
|
|
request.len / BDRV_SECTOR_SIZE);
|
|
if (ret < 0) {
|
|
LOG("discard failed");
|
|
reply.error = -ret;
|
|
}
|
|
if (nbd_co_send_reply(req, &reply, 0) < 0) {
|
|
goto out;
|
|
}
|
|
break;
|
|
default:
|
|
LOG("invalid request type (%u) received", request.type);
|
|
invalid_request:
|
|
reply.error = EINVAL;
|
|
error_reply:
|
|
if (nbd_co_send_reply(req, &reply, 0) < 0) {
|
|
goto out;
|
|
}
|
|
break;
|
|
}
|
|
|
|
TRACE("Request/Reply complete");
|
|
|
|
done:
|
|
nbd_request_put(req);
|
|
return;
|
|
|
|
out:
|
|
nbd_request_put(req);
|
|
client_close(client);
|
|
}
|
|
|
|
static void nbd_read(void *opaque)
|
|
{
|
|
NBDClient *client = opaque;
|
|
|
|
if (client->recv_coroutine) {
|
|
qemu_coroutine_enter(client->recv_coroutine, NULL);
|
|
} else {
|
|
qemu_coroutine_enter(qemu_coroutine_create(nbd_trip), client);
|
|
}
|
|
}
|
|
|
|
static void nbd_restart_write(void *opaque)
|
|
{
|
|
NBDClient *client = opaque;
|
|
|
|
qemu_coroutine_enter(client->send_coroutine, NULL);
|
|
}
|
|
|
|
static void nbd_set_handlers(NBDClient *client)
|
|
{
|
|
if (client->exp && client->exp->ctx) {
|
|
aio_set_fd_handler(client->exp->ctx, client->sock,
|
|
true,
|
|
client->can_read ? nbd_read : NULL,
|
|
client->send_coroutine ? nbd_restart_write : NULL,
|
|
client);
|
|
}
|
|
}
|
|
|
|
static void nbd_unset_handlers(NBDClient *client)
|
|
{
|
|
if (client->exp && client->exp->ctx) {
|
|
aio_set_fd_handler(client->exp->ctx, client->sock,
|
|
true, NULL, NULL, NULL);
|
|
}
|
|
}
|
|
|
|
static void nbd_update_can_read(NBDClient *client)
|
|
{
|
|
bool can_read = client->recv_coroutine ||
|
|
client->nb_requests < MAX_NBD_REQUESTS;
|
|
|
|
if (can_read != client->can_read) {
|
|
client->can_read = can_read;
|
|
nbd_set_handlers(client);
|
|
|
|
/* There is no need to invoke aio_notify(), since aio_set_fd_handler()
|
|
* in nbd_set_handlers() will have taken care of that */
|
|
}
|
|
}
|
|
|
|
static coroutine_fn void nbd_co_client_start(void *opaque)
|
|
{
|
|
NBDClientNewData *data = opaque;
|
|
NBDClient *client = data->client;
|
|
NBDExport *exp = client->exp;
|
|
|
|
if (exp) {
|
|
nbd_export_get(exp);
|
|
}
|
|
if (nbd_negotiate(data)) {
|
|
client_close(client);
|
|
goto out;
|
|
}
|
|
qemu_co_mutex_init(&client->send_lock);
|
|
nbd_set_handlers(client);
|
|
|
|
if (exp) {
|
|
QTAILQ_INSERT_TAIL(&exp->clients, client, next);
|
|
}
|
|
out:
|
|
g_free(data);
|
|
}
|
|
|
|
void nbd_client_new(NBDExport *exp, int csock, void (*close_fn)(NBDClient *))
|
|
{
|
|
NBDClient *client;
|
|
NBDClientNewData *data = g_new(NBDClientNewData, 1);
|
|
|
|
client = g_malloc0(sizeof(NBDClient));
|
|
client->refcount = 1;
|
|
client->exp = exp;
|
|
client->sock = csock;
|
|
client->can_read = true;
|
|
client->close = close_fn;
|
|
|
|
data->client = client;
|
|
data->co = qemu_coroutine_create(nbd_co_client_start);
|
|
qemu_coroutine_enter(data->co, data);
|
|
}
|