qemu-e2k/blockdev.c

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/*
* QEMU host block devices
*
* Copyright (c) 2003-2008 Fabrice Bellard
*
* This work is licensed under the terms of the GNU GPL, version 2 or
* later. See the COPYING file in the top-level directory.
*/
#include "sysemu/blockdev.h"
#include "hw/block-common.h"
#include "block/blockjob.h"
#include "monitor/monitor.h"
#include "qapi/qmp/qerror.h"
#include "qemu/option.h"
#include "qemu/config-file.h"
#include "qapi/qmp/types.h"
#include "sysemu/sysemu.h"
#include "block/block_int.h"
#include "qmp-commands.h"
#include "trace.h"
#include "sysemu/arch_init.h"
static QTAILQ_HEAD(drivelist, DriveInfo) drives = QTAILQ_HEAD_INITIALIZER(drives);
static const char *const if_name[IF_COUNT] = {
[IF_NONE] = "none",
[IF_IDE] = "ide",
[IF_SCSI] = "scsi",
[IF_FLOPPY] = "floppy",
[IF_PFLASH] = "pflash",
[IF_MTD] = "mtd",
[IF_SD] = "sd",
[IF_VIRTIO] = "virtio",
[IF_XEN] = "xen",
};
static const int if_max_devs[IF_COUNT] = {
/*
* Do not change these numbers! They govern how drive option
* index maps to unit and bus. That mapping is ABI.
*
* All controllers used to imlement if=T drives need to support
* if_max_devs[T] units, for any T with if_max_devs[T] != 0.
* Otherwise, some index values map to "impossible" bus, unit
* values.
*
* For instance, if you change [IF_SCSI] to 255, -drive
* if=scsi,index=12 no longer means bus=1,unit=5, but
* bus=0,unit=12. With an lsi53c895a controller (7 units max),
* the drive can't be set up. Regression.
*/
[IF_IDE] = 2,
[IF_SCSI] = 7,
};
/*
* We automatically delete the drive when a device using it gets
* unplugged. Questionable feature, but we can't just drop it.
* Device models call blockdev_mark_auto_del() to schedule the
* automatic deletion, and generic qdev code calls blockdev_auto_del()
* when deletion is actually safe.
*/
void blockdev_mark_auto_del(BlockDriverState *bs)
{
DriveInfo *dinfo = drive_get_by_blockdev(bs);
if (bs->job) {
block_job_cancel(bs->job);
}
if (dinfo) {
dinfo->auto_del = 1;
}
}
void blockdev_auto_del(BlockDriverState *bs)
{
DriveInfo *dinfo = drive_get_by_blockdev(bs);
if (dinfo && dinfo->auto_del) {
drive_put_ref(dinfo);
}
}
static int drive_index_to_bus_id(BlockInterfaceType type, int index)
{
int max_devs = if_max_devs[type];
return max_devs ? index / max_devs : 0;
}
static int drive_index_to_unit_id(BlockInterfaceType type, int index)
{
int max_devs = if_max_devs[type];
return max_devs ? index % max_devs : index;
}
QemuOpts *drive_def(const char *optstr)
{
return qemu_opts_parse(qemu_find_opts("drive"), optstr, 0);
}
QemuOpts *drive_add(BlockInterfaceType type, int index, const char *file,
const char *optstr)
{
QemuOpts *opts;
char buf[32];
opts = drive_def(optstr);
if (!opts) {
return NULL;
}
if (type != IF_DEFAULT) {
qemu_opt_set(opts, "if", if_name[type]);
}
if (index >= 0) {
snprintf(buf, sizeof(buf), "%d", index);
qemu_opt_set(opts, "index", buf);
}
if (file)
qemu_opt_set(opts, "file", file);
return opts;
}
DriveInfo *drive_get(BlockInterfaceType type, int bus, int unit)
{
DriveInfo *dinfo;
/* seek interface, bus and unit */
QTAILQ_FOREACH(dinfo, &drives, next) {
if (dinfo->type == type &&
dinfo->bus == bus &&
dinfo->unit == unit)
return dinfo;
}
return NULL;
}
DriveInfo *drive_get_by_index(BlockInterfaceType type, int index)
{
return drive_get(type,
drive_index_to_bus_id(type, index),
drive_index_to_unit_id(type, index));
}
int drive_get_max_bus(BlockInterfaceType type)
{
int max_bus;
DriveInfo *dinfo;
max_bus = -1;
QTAILQ_FOREACH(dinfo, &drives, next) {
if(dinfo->type == type &&
dinfo->bus > max_bus)
max_bus = dinfo->bus;
}
return max_bus;
}
/* Get a block device. This should only be used for single-drive devices
(e.g. SD/Floppy/MTD). Multi-disk devices (scsi/ide) should use the
appropriate bus. */
DriveInfo *drive_get_next(BlockInterfaceType type)
{
static int next_block_unit[IF_COUNT];
return drive_get(type, 0, next_block_unit[type]++);
}
DriveInfo *drive_get_by_blockdev(BlockDriverState *bs)
{
DriveInfo *dinfo;
QTAILQ_FOREACH(dinfo, &drives, next) {
if (dinfo->bdrv == bs) {
return dinfo;
}
}
return NULL;
}
static void bdrv_format_print(void *opaque, const char *name)
{
error_printf(" %s", name);
}
static void drive_uninit(DriveInfo *dinfo)
{
qemu_opts_del(dinfo->opts);
bdrv_delete(dinfo->bdrv);
g_free(dinfo->id);
QTAILQ_REMOVE(&drives, dinfo, next);
g_free(dinfo);
}
void drive_put_ref(DriveInfo *dinfo)
{
assert(dinfo->refcount);
if (--dinfo->refcount == 0) {
drive_uninit(dinfo);
}
}
void drive_get_ref(DriveInfo *dinfo)
{
dinfo->refcount++;
}
typedef struct {
QEMUBH *bh;
DriveInfo *dinfo;
} DrivePutRefBH;
static void drive_put_ref_bh(void *opaque)
{
DrivePutRefBH *s = opaque;
drive_put_ref(s->dinfo);
qemu_bh_delete(s->bh);
g_free(s);
}
/*
* Release a drive reference in a BH
*
* It is not possible to use drive_put_ref() from a callback function when the
* callers still need the drive. In such cases we schedule a BH to release the
* reference.
*/
static void drive_put_ref_bh_schedule(DriveInfo *dinfo)
{
DrivePutRefBH *s;
s = g_new(DrivePutRefBH, 1);
s->bh = qemu_bh_new(drive_put_ref_bh, s);
s->dinfo = dinfo;
qemu_bh_schedule(s->bh);
}
static int parse_block_error_action(const char *buf, bool is_read)
{
if (!strcmp(buf, "ignore")) {
return BLOCKDEV_ON_ERROR_IGNORE;
} else if (!is_read && !strcmp(buf, "enospc")) {
return BLOCKDEV_ON_ERROR_ENOSPC;
} else if (!strcmp(buf, "stop")) {
return BLOCKDEV_ON_ERROR_STOP;
} else if (!strcmp(buf, "report")) {
return BLOCKDEV_ON_ERROR_REPORT;
} else {
error_report("'%s' invalid %s error action",
buf, is_read ? "read" : "write");
return -1;
}
}
static bool do_check_io_limits(BlockIOLimit *io_limits)
{
bool bps_flag;
bool iops_flag;
assert(io_limits);
bps_flag = (io_limits->bps[BLOCK_IO_LIMIT_TOTAL] != 0)
&& ((io_limits->bps[BLOCK_IO_LIMIT_READ] != 0)
|| (io_limits->bps[BLOCK_IO_LIMIT_WRITE] != 0));
iops_flag = (io_limits->iops[BLOCK_IO_LIMIT_TOTAL] != 0)
&& ((io_limits->iops[BLOCK_IO_LIMIT_READ] != 0)
|| (io_limits->iops[BLOCK_IO_LIMIT_WRITE] != 0));
if (bps_flag || iops_flag) {
return false;
}
return true;
}
Support default block interfaces per QEMUMachine There are QEMUMachines that have neither IF_IDE nor IF_SCSI as a default/standard interface to their block devices / drives. Therefore, this patch introduces a new field default_block_type per QEMUMachine struct. The prior use_scsi field becomes thereby obsolete and is replaced through .default_block_type = IF_SCSI. This patch also changes the default for s390x to IF_VIRTIO and removes an early hack that converts IF_IDE drives. Other parties have already claimed interest (e.g. IF_SD for exynos) To create a sane default, for machines that dont specify a default_block_type, this patch makes IF_IDE = 0 and IF_NONE = 1. I checked all users of IF_NONE (blockdev.c and ww/device-hotplug.c) as well as IF_IDE and it seems that it is ok to change the defines - in other words, I found no obvious (to me) assumption in the code regarding IF_NONE==0. IF_NONE is only set if there is an explicit if=none. Without if=* the interface becomes IF_DEFAULT. I would suggest to have some additional care, e.g. by letting this patch sit some days in the block tree. Based on an initial patch from Einar Lueck <elelueck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> CC: Igor Mitsyanko <i.mitsyanko@samsung.com> CC: Markus Armbruster <armbru@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Alexander Graf <agraf@suse.de> Acked-by: Igor Mitsyanko <i.mitsyanko@samsung.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2012-11-20 15:30:34 +01:00
DriveInfo *drive_init(QemuOpts *opts, BlockInterfaceType block_default_type)
{
const char *buf;
const char *file = NULL;
const char *serial;
const char *mediastr = "";
BlockInterfaceType type;
enum { MEDIA_DISK, MEDIA_CDROM } media;
int bus_id, unit_id;
int cyls, heads, secs, translation;
BlockDriver *drv = NULL;
int max_devs;
int index;
int ro = 0;
int bdrv_flags = 0;
int on_read_error, on_write_error;
const char *devaddr;
DriveInfo *dinfo;
BlockIOLimit io_limits;
int snapshot = 0;
bool copy_on_read;
int ret;
translation = BIOS_ATA_TRANSLATION_AUTO;
media = MEDIA_DISK;
/* extract parameters */
bus_id = qemu_opt_get_number(opts, "bus", 0);
unit_id = qemu_opt_get_number(opts, "unit", -1);
index = qemu_opt_get_number(opts, "index", -1);
cyls = qemu_opt_get_number(opts, "cyls", 0);
heads = qemu_opt_get_number(opts, "heads", 0);
secs = qemu_opt_get_number(opts, "secs", 0);
snapshot = qemu_opt_get_bool(opts, "snapshot", 0);
ro = qemu_opt_get_bool(opts, "readonly", 0);
copy_on_read = qemu_opt_get_bool(opts, "copy-on-read", false);
file = qemu_opt_get(opts, "file");
serial = qemu_opt_get(opts, "serial");
if ((buf = qemu_opt_get(opts, "if")) != NULL) {
for (type = 0; type < IF_COUNT && strcmp(buf, if_name[type]); type++)
;
if (type == IF_COUNT) {
error_report("unsupported bus type '%s'", buf);
return NULL;
}
} else {
Support default block interfaces per QEMUMachine There are QEMUMachines that have neither IF_IDE nor IF_SCSI as a default/standard interface to their block devices / drives. Therefore, this patch introduces a new field default_block_type per QEMUMachine struct. The prior use_scsi field becomes thereby obsolete and is replaced through .default_block_type = IF_SCSI. This patch also changes the default for s390x to IF_VIRTIO and removes an early hack that converts IF_IDE drives. Other parties have already claimed interest (e.g. IF_SD for exynos) To create a sane default, for machines that dont specify a default_block_type, this patch makes IF_IDE = 0 and IF_NONE = 1. I checked all users of IF_NONE (blockdev.c and ww/device-hotplug.c) as well as IF_IDE and it seems that it is ok to change the defines - in other words, I found no obvious (to me) assumption in the code regarding IF_NONE==0. IF_NONE is only set if there is an explicit if=none. Without if=* the interface becomes IF_DEFAULT. I would suggest to have some additional care, e.g. by letting this patch sit some days in the block tree. Based on an initial patch from Einar Lueck <elelueck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> CC: Igor Mitsyanko <i.mitsyanko@samsung.com> CC: Markus Armbruster <armbru@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Alexander Graf <agraf@suse.de> Acked-by: Igor Mitsyanko <i.mitsyanko@samsung.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2012-11-20 15:30:34 +01:00
type = block_default_type;
}
max_devs = if_max_devs[type];
if (cyls || heads || secs) {
if (cyls < 1) {
error_report("invalid physical cyls number");
return NULL;
}
if (heads < 1) {
error_report("invalid physical heads number");
return NULL;
}
if (secs < 1) {
error_report("invalid physical secs number");
return NULL;
}
}
if ((buf = qemu_opt_get(opts, "trans")) != NULL) {
if (!cyls) {
error_report("'%s' trans must be used with cyls, heads and secs",
buf);
return NULL;
}
if (!strcmp(buf, "none"))
translation = BIOS_ATA_TRANSLATION_NONE;
else if (!strcmp(buf, "lba"))
translation = BIOS_ATA_TRANSLATION_LBA;
else if (!strcmp(buf, "auto"))
translation = BIOS_ATA_TRANSLATION_AUTO;
else {
error_report("'%s' invalid translation type", buf);
return NULL;
}
}
if ((buf = qemu_opt_get(opts, "media")) != NULL) {
if (!strcmp(buf, "disk")) {
media = MEDIA_DISK;
} else if (!strcmp(buf, "cdrom")) {
if (cyls || secs || heads) {
error_report("CHS can't be set with media=%s", buf);
return NULL;
}
media = MEDIA_CDROM;
} else {
error_report("'%s' invalid media", buf);
return NULL;
}
}
bdrv_flags |= BDRV_O_CACHE_WB;
if ((buf = qemu_opt_get(opts, "cache")) != NULL) {
if (bdrv_parse_cache_flags(buf, &bdrv_flags) != 0) {
error_report("invalid cache option");
return NULL;
}
}
#ifdef CONFIG_LINUX_AIO
if ((buf = qemu_opt_get(opts, "aio")) != NULL) {
if (!strcmp(buf, "native")) {
bdrv_flags |= BDRV_O_NATIVE_AIO;
} else if (!strcmp(buf, "threads")) {
/* this is the default */
} else {
error_report("invalid aio option");
return NULL;
}
}
#endif
if ((buf = qemu_opt_get(opts, "format")) != NULL) {
if (is_help_option(buf)) {
error_printf("Supported formats:");
bdrv_iterate_format(bdrv_format_print, NULL);
error_printf("\n");
return NULL;
}
drv = bdrv_find_whitelisted_format(buf);
if (!drv) {
error_report("'%s' invalid format", buf);
return NULL;
}
}
/* disk I/O throttling */
io_limits.bps[BLOCK_IO_LIMIT_TOTAL] =
qemu_opt_get_number(opts, "bps", 0);
io_limits.bps[BLOCK_IO_LIMIT_READ] =
qemu_opt_get_number(opts, "bps_rd", 0);
io_limits.bps[BLOCK_IO_LIMIT_WRITE] =
qemu_opt_get_number(opts, "bps_wr", 0);
io_limits.iops[BLOCK_IO_LIMIT_TOTAL] =
qemu_opt_get_number(opts, "iops", 0);
io_limits.iops[BLOCK_IO_LIMIT_READ] =
qemu_opt_get_number(opts, "iops_rd", 0);
io_limits.iops[BLOCK_IO_LIMIT_WRITE] =
qemu_opt_get_number(opts, "iops_wr", 0);
if (!do_check_io_limits(&io_limits)) {
error_report("bps(iops) and bps_rd/bps_wr(iops_rd/iops_wr) "
"cannot be used at the same time");
return NULL;
}
if (qemu_opt_get(opts, "boot") != NULL) {
fprintf(stderr, "qemu-kvm: boot=on|off is deprecated and will be "
"ignored. Future versions will reject this parameter. Please "
"update your scripts.\n");
}
on_write_error = BLOCKDEV_ON_ERROR_ENOSPC;
if ((buf = qemu_opt_get(opts, "werror")) != NULL) {
if (type != IF_IDE && type != IF_SCSI && type != IF_VIRTIO && type != IF_NONE) {
error_report("werror is not supported by this bus type");
return NULL;
}
on_write_error = parse_block_error_action(buf, 0);
if (on_write_error < 0) {
return NULL;
}
}
on_read_error = BLOCKDEV_ON_ERROR_REPORT;
if ((buf = qemu_opt_get(opts, "rerror")) != NULL) {
if (type != IF_IDE && type != IF_VIRTIO && type != IF_SCSI && type != IF_NONE) {
error_report("rerror is not supported by this bus type");
return NULL;
}
on_read_error = parse_block_error_action(buf, 1);
if (on_read_error < 0) {
return NULL;
}
}
if ((devaddr = qemu_opt_get(opts, "addr")) != NULL) {
if (type != IF_VIRTIO) {
error_report("addr is not supported by this bus type");
return NULL;
}
}
/* compute bus and unit according index */
if (index != -1) {
if (bus_id != 0 || unit_id != -1) {
error_report("index cannot be used with bus and unit");
return NULL;
}
bus_id = drive_index_to_bus_id(type, index);
unit_id = drive_index_to_unit_id(type, index);
}
/* if user doesn't specify a unit_id,
* try to find the first free
*/
if (unit_id == -1) {
unit_id = 0;
while (drive_get(type, bus_id, unit_id) != NULL) {
unit_id++;
if (max_devs && unit_id >= max_devs) {
unit_id -= max_devs;
bus_id++;
}
}
}
/* check unit id */
if (max_devs && unit_id >= max_devs) {
error_report("unit %d too big (max is %d)",
unit_id, max_devs - 1);
return NULL;
}
/*
* catch multiple definitions
*/
if (drive_get(type, bus_id, unit_id) != NULL) {
error_report("drive with bus=%d, unit=%d (index=%d) exists",
bus_id, unit_id, index);
return NULL;
}
/* init */
dinfo = g_malloc0(sizeof(*dinfo));
if ((buf = qemu_opts_id(opts)) != NULL) {
dinfo->id = g_strdup(buf);
} else {
/* no id supplied -> create one */
dinfo->id = g_malloc0(32);
if (type == IF_IDE || type == IF_SCSI)
mediastr = (media == MEDIA_CDROM) ? "-cd" : "-hd";
if (max_devs)
snprintf(dinfo->id, 32, "%s%i%s%i",
if_name[type], bus_id, mediastr, unit_id);
else
snprintf(dinfo->id, 32, "%s%s%i",
if_name[type], mediastr, unit_id);
}
dinfo->bdrv = bdrv_new(dinfo->id);
dinfo->bdrv->open_flags = snapshot ? BDRV_O_SNAPSHOT : 0;
dinfo->bdrv->read_only = ro;
dinfo->devaddr = devaddr;
dinfo->type = type;
dinfo->bus = bus_id;
dinfo->unit = unit_id;
dinfo->cyls = cyls;
dinfo->heads = heads;
dinfo->secs = secs;
dinfo->trans = translation;
dinfo->opts = opts;
dinfo->refcount = 1;
dinfo->serial = serial;
QTAILQ_INSERT_TAIL(&drives, dinfo, next);
bdrv_set_on_error(dinfo->bdrv, on_read_error, on_write_error);
/* disk I/O throttling */
bdrv_set_io_limits(dinfo->bdrv, &io_limits);
switch(type) {
case IF_IDE:
case IF_SCSI:
case IF_XEN:
case IF_NONE:
dinfo->media_cd = media == MEDIA_CDROM;
break;
case IF_SD:
case IF_FLOPPY:
case IF_PFLASH:
case IF_MTD:
break;
case IF_VIRTIO:
/* add virtio block device */
opts = qemu_opts_create_nofail(qemu_find_opts("device"));
if (arch_type == QEMU_ARCH_S390X) {
qemu_opt_set(opts, "driver", "virtio-blk-s390");
} else {
qemu_opt_set(opts, "driver", "virtio-blk-pci");
}
qemu_opt_set(opts, "drive", dinfo->id);
if (devaddr)
qemu_opt_set(opts, "addr", devaddr);
break;
default:
abort();
}
if (!file || !*file) {
return dinfo;
}
if (snapshot) {
/* always use cache=unsafe with snapshot */
bdrv_flags &= ~BDRV_O_CACHE_MASK;
bdrv_flags |= (BDRV_O_SNAPSHOT|BDRV_O_CACHE_WB|BDRV_O_NO_FLUSH);
}
if (copy_on_read) {
bdrv_flags |= BDRV_O_COPY_ON_READ;
}
if (runstate_check(RUN_STATE_INMIGRATE)) {
bdrv_flags |= BDRV_O_INCOMING;
}
if (media == MEDIA_CDROM) {
/* CDROM is fine for any interface, don't check. */
ro = 1;
} else if (ro == 1) {
if (type != IF_SCSI && type != IF_VIRTIO && type != IF_FLOPPY &&
type != IF_NONE && type != IF_PFLASH) {
error_report("readonly not supported by this bus type");
goto err;
}
}
bdrv_flags |= ro ? 0 : BDRV_O_RDWR;
if (ro && copy_on_read) {
error_report("warning: disabling copy_on_read on readonly drive");
}
ret = bdrv_open(dinfo->bdrv, file, bdrv_flags, drv);
if (ret < 0) {
error_report("could not open disk image %s: %s",
file, strerror(-ret));
goto err;
}
if (bdrv_key_required(dinfo->bdrv))
autostart = 0;
return dinfo;
err:
bdrv_delete(dinfo->bdrv);
g_free(dinfo->id);
QTAILQ_REMOVE(&drives, dinfo, next);
g_free(dinfo);
return NULL;
}
void do_commit(Monitor *mon, const QDict *qdict)
{
const char *device = qdict_get_str(qdict, "device");
BlockDriverState *bs;
int ret;
if (!strcmp(device, "all")) {
ret = bdrv_commit_all();
if (ret == -EBUSY) {
qerror_report(QERR_DEVICE_IN_USE, device);
return;
}
} else {
bs = bdrv_find(device);
if (!bs) {
qerror_report(QERR_DEVICE_NOT_FOUND, device);
return;
}
ret = bdrv_commit(bs);
if (ret == -EBUSY) {
qerror_report(QERR_DEVICE_IN_USE, device);
return;
}
}
}
static void blockdev_do_action(int kind, void *data, Error **errp)
{
BlockdevAction action;
BlockdevActionList list;
action.kind = kind;
action.data = data;
list.value = &action;
list.next = NULL;
qmp_transaction(&list, errp);
}
void qmp_blockdev_snapshot_sync(const char *device, const char *snapshot_file,
bool has_format, const char *format,
bool has_mode, enum NewImageMode mode,
Error **errp)
{
BlockdevSnapshot snapshot = {
.device = (char *) device,
.snapshot_file = (char *) snapshot_file,
.has_format = has_format,
.format = (char *) format,
.has_mode = has_mode,
.mode = mode,
};
blockdev_do_action(BLOCKDEV_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC, &snapshot,
errp);
}
/* New and old BlockDriverState structs for group snapshots */
typedef struct BlkTransactionStates {
BlockDriverState *old_bs;
BlockDriverState *new_bs;
QSIMPLEQ_ENTRY(BlkTransactionStates) entry;
} BlkTransactionStates;
/*
* 'Atomic' group snapshots. The snapshots are taken as a set, and if any fail
* then we do not pivot any of the devices in the group, and abandon the
* snapshots
*/
void qmp_transaction(BlockdevActionList *dev_list, Error **errp)
{
int ret = 0;
BlockdevActionList *dev_entry = dev_list;
BlkTransactionStates *states, *next;
Error *local_err = NULL;
QSIMPLEQ_HEAD(snap_bdrv_states, BlkTransactionStates) snap_bdrv_states;
QSIMPLEQ_INIT(&snap_bdrv_states);
/* drain all i/o before any snapshots */
bdrv_drain_all();
/* We don't do anything in this loop that commits us to the snapshot */
while (NULL != dev_entry) {
BlockdevAction *dev_info = NULL;
BlockDriver *proto_drv;
BlockDriver *drv;
int flags;
enum NewImageMode mode;
const char *new_image_file;
const char *device;
const char *format = "qcow2";
dev_info = dev_entry->value;
dev_entry = dev_entry->next;
states = g_malloc0(sizeof(BlkTransactionStates));
QSIMPLEQ_INSERT_TAIL(&snap_bdrv_states, states, entry);
switch (dev_info->kind) {
case BLOCKDEV_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC:
device = dev_info->blockdev_snapshot_sync->device;
if (!dev_info->blockdev_snapshot_sync->has_mode) {
dev_info->blockdev_snapshot_sync->mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS;
}
new_image_file = dev_info->blockdev_snapshot_sync->snapshot_file;
if (dev_info->blockdev_snapshot_sync->has_format) {
format = dev_info->blockdev_snapshot_sync->format;
}
mode = dev_info->blockdev_snapshot_sync->mode;
break;
default:
abort();
}
drv = bdrv_find_format(format);
if (!drv) {
error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
goto delete_and_fail;
}
states->old_bs = bdrv_find(device);
if (!states->old_bs) {
error_set(errp, QERR_DEVICE_NOT_FOUND, device);
goto delete_and_fail;
}
if (!bdrv_is_inserted(states->old_bs)) {
error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
goto delete_and_fail;
}
if (bdrv_in_use(states->old_bs)) {
error_set(errp, QERR_DEVICE_IN_USE, device);
goto delete_and_fail;
}
if (!bdrv_is_read_only(states->old_bs)) {
if (bdrv_flush(states->old_bs)) {
error_set(errp, QERR_IO_ERROR);
goto delete_and_fail;
}
}
flags = states->old_bs->open_flags;
proto_drv = bdrv_find_protocol(new_image_file);
if (!proto_drv) {
error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
goto delete_and_fail;
}
/* create new image w/backing file */
if (mode != NEW_IMAGE_MODE_EXISTING) {
bdrv_img_create(new_image_file, format,
states->old_bs->filename,
states->old_bs->drv->format_name,
NULL, -1, flags, &local_err);
if (error_is_set(&local_err)) {
error_propagate(errp, local_err);
goto delete_and_fail;
}
}
/* We will manually add the backing_hd field to the bs later */
states->new_bs = bdrv_new("");
ret = bdrv_open(states->new_bs, new_image_file,
flags | BDRV_O_NO_BACKING, drv);
if (ret != 0) {
error_set(errp, QERR_OPEN_FILE_FAILED, new_image_file);
goto delete_and_fail;
}
}
/* Now we are going to do the actual pivot. Everything up to this point
* is reversible, but we are committed at this point */
QSIMPLEQ_FOREACH(states, &snap_bdrv_states, entry) {
/* This removes our old bs from the bdrv_states, and adds the new bs */
bdrv_append(states->new_bs, states->old_bs);
/* We don't need (or want) to use the transactional
* bdrv_reopen_multiple() across all the entries at once, because we
* don't want to abort all of them if one of them fails the reopen */
bdrv_reopen(states->new_bs, states->new_bs->open_flags & ~BDRV_O_RDWR,
NULL);
}
/* success */
goto exit;
delete_and_fail:
/*
* failure, and it is all-or-none; abandon each new bs, and keep using
* the original bs for all images
*/
QSIMPLEQ_FOREACH(states, &snap_bdrv_states, entry) {
if (states->new_bs) {
bdrv_delete(states->new_bs);
}
}
exit:
QSIMPLEQ_FOREACH_SAFE(states, &snap_bdrv_states, entry, next) {
g_free(states);
}
}
static void eject_device(BlockDriverState *bs, int force, Error **errp)
{
if (bdrv_in_use(bs)) {
error_set(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs));
return;
}
block: Clean up remaining users of "removable" BlockDriverState member removable is a confused mess. It is true when an ide-cd, scsi-cd or floppy qdev is attached, or when the BlockDriverState was created with -drive if={floppy,sd} or -drive if={ide,scsi,xen,none},media=cdrom ("created removable"), except when an ide-hd, scsi-hd, scsi-generic or virtio-blk qdev is attached. Three users remain: 1. eject_device(), via bdrv_is_removable() uses it to determine whether a block device can eject media. 2. bdrv_info() is monitor command "info block". QMP documentation says "true if the device is removable, false otherwise". From the monitor user's point of view, the only sensible interpretation of "is removable" is "can eject media with monitor commands eject and change". A block device can eject media unless a device is attached that doesn't support it. Switch the two users over to new bdrv_dev_has_removable_media() that returns exactly that. 3. bdrv_getlength() uses to suppress its length cache when media can change (see commit 46a4e4e6). Media change is either monitor command change (updates the length cache), monitor command eject (doesn't update the length cache, easily fixable), or physical media change (invalidates length cache, not so easily fixable). I'm refraining from improving anything here, because this series is long enough already. Instead, I simply switch it over to bdrv_dev_has_removable_media() as well. This changes the behavior of the length cache and of monitor commands eject and change in two cases: a. drive not created removable, no device attached The commit makes the drive removable, and defeats the length cache. Example: -drive if=none b. drive created removable, but the attached drive is non-removable, and doesn't call bdrv_set_removable(..., 0) (most devices don't) The commit makes the drive non-removable, and enables the length cache. Example: -drive if=xen,media=cdrom -M xenpv The other non-removable devices that don't call bdrv_set_removable() can't currently use a drive created removable, either because they aren't qdevified, or because they lack a drive property. Won't stay that way. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-06 18:58:51 +02:00
if (!bdrv_dev_has_removable_media(bs)) {
error_set(errp, QERR_DEVICE_NOT_REMOVABLE, bdrv_get_device_name(bs));
return;
}
if (bdrv_dev_is_medium_locked(bs) && !bdrv_dev_is_tray_open(bs)) {
bdrv_dev_eject_request(bs, force);
if (!force) {
error_set(errp, QERR_DEVICE_LOCKED, bdrv_get_device_name(bs));
return;
}
}
2010-06-02 00:12:19 +02:00
bdrv_close(bs);
}
void qmp_eject(const char *device, bool has_force, bool force, Error **errp)
{
BlockDriverState *bs;
bs = bdrv_find(device);
if (!bs) {
error_set(errp, QERR_DEVICE_NOT_FOUND, device);
return;
}
eject_device(bs, force, errp);
}
void qmp_block_passwd(const char *device, const char *password, Error **errp)
{
BlockDriverState *bs;
int err;
bs = bdrv_find(device);
if (!bs) {
error_set(errp, QERR_DEVICE_NOT_FOUND, device);
return;
}
err = bdrv_set_key(bs, password);
if (err == -EINVAL) {
error_set(errp, QERR_DEVICE_NOT_ENCRYPTED, bdrv_get_device_name(bs));
return;
} else if (err < 0) {
error_set(errp, QERR_INVALID_PASSWORD);
return;
}
}
static void qmp_bdrv_open_encrypted(BlockDriverState *bs, const char *filename,
int bdrv_flags, BlockDriver *drv,
const char *password, Error **errp)
{
if (bdrv_open(bs, filename, bdrv_flags, drv) < 0) {
error_set(errp, QERR_OPEN_FILE_FAILED, filename);
return;
}
if (bdrv_key_required(bs)) {
if (password) {
if (bdrv_set_key(bs, password) < 0) {
error_set(errp, QERR_INVALID_PASSWORD);
}
} else {
error_set(errp, QERR_DEVICE_ENCRYPTED, bdrv_get_device_name(bs),
bdrv_get_encrypted_filename(bs));
}
} else if (password) {
error_set(errp, QERR_DEVICE_NOT_ENCRYPTED, bdrv_get_device_name(bs));
}
}
void qmp_change_blockdev(const char *device, const char *filename,
bool has_format, const char *format, Error **errp)
{
BlockDriverState *bs;
BlockDriver *drv = NULL;
int bdrv_flags;
Error *err = NULL;
bs = bdrv_find(device);
if (!bs) {
error_set(errp, QERR_DEVICE_NOT_FOUND, device);
return;
}
if (format) {
drv = bdrv_find_whitelisted_format(format);
if (!drv) {
error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
return;
}
}
eject_device(bs, 0, &err);
if (error_is_set(&err)) {
error_propagate(errp, err);
return;
}
bdrv_flags = bdrv_is_read_only(bs) ? 0 : BDRV_O_RDWR;
bdrv_flags |= bdrv_is_snapshot(bs) ? BDRV_O_SNAPSHOT : 0;
qmp_bdrv_open_encrypted(bs, filename, bdrv_flags, drv, NULL, errp);
}
/* throttling disk I/O limits */
void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
int64_t bps_wr, int64_t iops, int64_t iops_rd,
int64_t iops_wr, Error **errp)
{
BlockIOLimit io_limits;
BlockDriverState *bs;
bs = bdrv_find(device);
if (!bs) {
error_set(errp, QERR_DEVICE_NOT_FOUND, device);
return;
}
io_limits.bps[BLOCK_IO_LIMIT_TOTAL] = bps;
io_limits.bps[BLOCK_IO_LIMIT_READ] = bps_rd;
io_limits.bps[BLOCK_IO_LIMIT_WRITE] = bps_wr;
io_limits.iops[BLOCK_IO_LIMIT_TOTAL]= iops;
io_limits.iops[BLOCK_IO_LIMIT_READ] = iops_rd;
io_limits.iops[BLOCK_IO_LIMIT_WRITE]= iops_wr;
if (!do_check_io_limits(&io_limits)) {
error_set(errp, QERR_INVALID_PARAMETER_COMBINATION);
return;
}
bs->io_limits = io_limits;
bs->slice_time = BLOCK_IO_SLICE_TIME;
if (!bs->io_limits_enabled && bdrv_io_limits_enabled(bs)) {
bdrv_io_limits_enable(bs);
} else if (bs->io_limits_enabled && !bdrv_io_limits_enabled(bs)) {
bdrv_io_limits_disable(bs);
} else {
if (bs->block_timer) {
qemu_mod_timer(bs->block_timer, qemu_get_clock_ns(vm_clock));
}
}
}
int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data)
{
const char *id = qdict_get_str(qdict, "id");
BlockDriverState *bs;
bs = bdrv_find(id);
if (!bs) {
qerror_report(QERR_DEVICE_NOT_FOUND, id);
return -1;
}
if (bdrv_in_use(bs)) {
qerror_report(QERR_DEVICE_IN_USE, id);
return -1;
}
/* quiesce block driver; prevent further io */
bdrv_drain_all();
bdrv_flush(bs);
bdrv_close(bs);
/* if we have a device attached to this BlockDriverState
Do not delete BlockDriverState when deleting the drive When removing a drive from the host-side via drive_del we currently have the following path: drive_del qemu_aio_flush() bdrv_close() // zaps bs->drv, which makes any subsequent I/O get // dropped. Works as designed drive_uninit() bdrv_delete() // frees the bs. Since the device is still connected to // bs, any subsequent I/O is a use-after-free. The value of bs->drv becomes unpredictable on free. As long as it remains null, I/O still gets dropped, however it could become non-null at any point after the free resulting SEGVs or other QEMU state corruption. To resolve this issue as simply as possible, we can chose to not actually delete the BlockDriverState pointer. Since bdrv_close() handles setting the drv pointer to NULL, we just need to remove the BlockDriverState from the QLIST that is used to enumerate the block devices. This is currently handled within bdrv_delete, so move this into its own function, bdrv_make_anon(). The result is that we can now invoke drive_del, this closes the file descriptors and sets BlockDriverState->drv to NULL which prevents futher IO to the device, and since we do not free BlockDriverState, we don't have to worry about the copy retained in the block devices. We also don't attempt to remove the qdev property since we are no longer deleting the BlockDriverState on drives with associated drives. This also allows for removing Drives with no devices associated either. Reported-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Ryan Harper <ryanh@us.ibm.com> Acked-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-03-30 03:51:47 +02:00
* then we need to make the drive anonymous until the device
* can be removed. If this is a drive with no device backing
* then we can just get rid of the block driver state right here.
*/
if (bdrv_get_attached_dev(bs)) {
Do not delete BlockDriverState when deleting the drive When removing a drive from the host-side via drive_del we currently have the following path: drive_del qemu_aio_flush() bdrv_close() // zaps bs->drv, which makes any subsequent I/O get // dropped. Works as designed drive_uninit() bdrv_delete() // frees the bs. Since the device is still connected to // bs, any subsequent I/O is a use-after-free. The value of bs->drv becomes unpredictable on free. As long as it remains null, I/O still gets dropped, however it could become non-null at any point after the free resulting SEGVs or other QEMU state corruption. To resolve this issue as simply as possible, we can chose to not actually delete the BlockDriverState pointer. Since bdrv_close() handles setting the drv pointer to NULL, we just need to remove the BlockDriverState from the QLIST that is used to enumerate the block devices. This is currently handled within bdrv_delete, so move this into its own function, bdrv_make_anon(). The result is that we can now invoke drive_del, this closes the file descriptors and sets BlockDriverState->drv to NULL which prevents futher IO to the device, and since we do not free BlockDriverState, we don't have to worry about the copy retained in the block devices. We also don't attempt to remove the qdev property since we are no longer deleting the BlockDriverState on drives with associated drives. This also allows for removing Drives with no devices associated either. Reported-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Ryan Harper <ryanh@us.ibm.com> Acked-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-03-30 03:51:47 +02:00
bdrv_make_anon(bs);
} else {
drive_uninit(drive_get_by_blockdev(bs));
}
return 0;
}
void qmp_block_resize(const char *device, int64_t size, Error **errp)
{
BlockDriverState *bs;
bs = bdrv_find(device);
if (!bs) {
error_set(errp, QERR_DEVICE_NOT_FOUND, device);
return;
}
if (size < 0) {
error_set(errp, QERR_INVALID_PARAMETER_VALUE, "size", "a >0 size");
return;
}
switch (bdrv_truncate(bs, size)) {
case 0:
break;
case -ENOMEDIUM:
error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
break;
case -ENOTSUP:
error_set(errp, QERR_UNSUPPORTED);
break;
case -EACCES:
error_set(errp, QERR_DEVICE_IS_READ_ONLY, device);
break;
case -EBUSY:
error_set(errp, QERR_DEVICE_IN_USE, device);
break;
default:
error_set(errp, QERR_UNDEFINED_ERROR);
break;
}
}
static void block_job_cb(void *opaque, int ret)
{
BlockDriverState *bs = opaque;
QObject *obj;
trace_block_job_cb(bs, bs->job, ret);
assert(bs->job);
obj = qobject_from_block_job(bs->job);
if (ret < 0) {
QDict *dict = qobject_to_qdict(obj);
qdict_put(dict, "error", qstring_from_str(strerror(-ret)));
}
if (block_job_is_cancelled(bs->job)) {
monitor_protocol_event(QEVENT_BLOCK_JOB_CANCELLED, obj);
} else {
monitor_protocol_event(QEVENT_BLOCK_JOB_COMPLETED, obj);
}
qobject_decref(obj);
drive_put_ref_bh_schedule(drive_get_by_blockdev(bs));
}
void qmp_block_stream(const char *device, bool has_base,
const char *base, bool has_speed, int64_t speed,
bool has_on_error, BlockdevOnError on_error,
Error **errp)
{
BlockDriverState *bs;
BlockDriverState *base_bs = NULL;
Error *local_err = NULL;
if (!has_on_error) {
on_error = BLOCKDEV_ON_ERROR_REPORT;
}
bs = bdrv_find(device);
if (!bs) {
error_set(errp, QERR_DEVICE_NOT_FOUND, device);
return;
}
if (base) {
base_bs = bdrv_find_backing_image(bs, base);
if (base_bs == NULL) {
error_set(errp, QERR_BASE_NOT_FOUND, base);
return;
}
}
stream_start(bs, base_bs, base, has_speed ? speed : 0,
on_error, block_job_cb, bs, &local_err);
if (error_is_set(&local_err)) {
error_propagate(errp, local_err);
return;
}
/* Grab a reference so hotplug does not delete the BlockDriverState from
* underneath us.
*/
drive_get_ref(drive_get_by_blockdev(bs));
trace_qmp_block_stream(bs, bs->job);
}
void qmp_block_commit(const char *device,
bool has_base, const char *base, const char *top,
bool has_speed, int64_t speed,
Error **errp)
{
BlockDriverState *bs;
BlockDriverState *base_bs, *top_bs;
Error *local_err = NULL;
/* This will be part of the QMP command, if/when the
* BlockdevOnError change for blkmirror makes it in
*/
BlockdevOnError on_error = BLOCKDEV_ON_ERROR_REPORT;
/* drain all i/o before commits */
bdrv_drain_all();
bs = bdrv_find(device);
if (!bs) {
error_set(errp, QERR_DEVICE_NOT_FOUND, device);
return;
}
/* default top_bs is the active layer */
top_bs = bs;
if (top) {
if (strcmp(bs->filename, top) != 0) {
top_bs = bdrv_find_backing_image(bs, top);
}
}
if (top_bs == NULL) {
error_setg(errp, "Top image file %s not found", top ? top : "NULL");
return;
}
if (has_base && base) {
base_bs = bdrv_find_backing_image(top_bs, base);
} else {
base_bs = bdrv_find_base(top_bs);
}
if (base_bs == NULL) {
error_set(errp, QERR_BASE_NOT_FOUND, base ? base : "NULL");
return;
}
commit_start(bs, base_bs, top_bs, speed, on_error, block_job_cb, bs,
&local_err);
if (local_err != NULL) {
error_propagate(errp, local_err);
return;
}
/* Grab a reference so hotplug does not delete the BlockDriverState from
* underneath us.
*/
drive_get_ref(drive_get_by_blockdev(bs));
}
void qmp_drive_mirror(const char *device, const char *target,
bool has_format, const char *format,
enum MirrorSyncMode sync,
bool has_mode, enum NewImageMode mode,
bool has_speed, int64_t speed,
bool has_on_source_error, BlockdevOnError on_source_error,
bool has_on_target_error, BlockdevOnError on_target_error,
Error **errp)
{
BlockDriverInfo bdi;
BlockDriverState *bs;
BlockDriverState *source, *target_bs;
BlockDriver *proto_drv;
BlockDriver *drv = NULL;
Error *local_err = NULL;
int flags;
uint64_t size;
int ret;
if (!has_speed) {
speed = 0;
}
if (!has_on_source_error) {
on_source_error = BLOCKDEV_ON_ERROR_REPORT;
}
if (!has_on_target_error) {
on_target_error = BLOCKDEV_ON_ERROR_REPORT;
}
if (!has_mode) {
mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS;
}
bs = bdrv_find(device);
if (!bs) {
error_set(errp, QERR_DEVICE_NOT_FOUND, device);
return;
}
if (!bdrv_is_inserted(bs)) {
error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
return;
}
if (!has_format) {
format = mode == NEW_IMAGE_MODE_EXISTING ? NULL : bs->drv->format_name;
}
if (format) {
drv = bdrv_find_format(format);
if (!drv) {
error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
return;
}
}
if (bdrv_in_use(bs)) {
error_set(errp, QERR_DEVICE_IN_USE, device);
return;
}
flags = bs->open_flags | BDRV_O_RDWR;
source = bs->backing_hd;
if (!source && sync == MIRROR_SYNC_MODE_TOP) {
sync = MIRROR_SYNC_MODE_FULL;
}
proto_drv = bdrv_find_protocol(target);
if (!proto_drv) {
error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
return;
}
if (sync == MIRROR_SYNC_MODE_FULL && mode != NEW_IMAGE_MODE_EXISTING) {
/* create new image w/o backing file */
assert(format && drv);
bdrv_get_geometry(bs, &size);
size *= 512;
bdrv_img_create(target, format,
NULL, NULL, NULL, size, flags, &local_err);
} else {
switch (mode) {
case NEW_IMAGE_MODE_EXISTING:
ret = 0;
break;
case NEW_IMAGE_MODE_ABSOLUTE_PATHS:
/* create new image with backing file */
bdrv_img_create(target, format,
source->filename,
source->drv->format_name,
NULL, -1, flags, &local_err);
break;
default:
abort();
}
}
if (error_is_set(&local_err)) {
error_propagate(errp, local_err);
return;
}
target_bs = bdrv_new("");
ret = bdrv_open(target_bs, target, flags | BDRV_O_NO_BACKING, drv);
if (ret < 0) {
bdrv_delete(target_bs);
error_set(errp, QERR_OPEN_FILE_FAILED, target);
return;
}
/* We need a backing file if we will copy parts of a cluster. */
if (bdrv_get_info(target_bs, &bdi) >= 0 && bdi.cluster_size != 0 &&
bdi.cluster_size >= BDRV_SECTORS_PER_DIRTY_CHUNK * 512) {
ret = bdrv_open_backing_file(target_bs);
if (ret < 0) {
bdrv_delete(target_bs);
error_set(errp, QERR_OPEN_FILE_FAILED, target);
return;
}
}
mirror_start(bs, target_bs, speed, sync, on_source_error, on_target_error,
block_job_cb, bs, &local_err);
if (local_err != NULL) {
bdrv_delete(target_bs);
error_propagate(errp, local_err);
return;
}
/* Grab a reference so hotplug does not delete the BlockDriverState from
* underneath us.
*/
drive_get_ref(drive_get_by_blockdev(bs));
}
static BlockJob *find_block_job(const char *device)
{
BlockDriverState *bs;
bs = bdrv_find(device);
if (!bs || !bs->job) {
return NULL;
}
return bs->job;
}
void qmp_block_job_set_speed(const char *device, int64_t speed, Error **errp)
{
BlockJob *job = find_block_job(device);
if (!job) {
error_set(errp, QERR_BLOCK_JOB_NOT_ACTIVE, device);
return;
}
block_job_set_speed(job, speed, errp);
}
void qmp_block_job_cancel(const char *device,
bool has_force, bool force, Error **errp)
{
BlockJob *job = find_block_job(device);
if (!has_force) {
force = false;
}
if (!job) {
error_set(errp, QERR_BLOCK_JOB_NOT_ACTIVE, device);
return;
}
if (job->paused && !force) {
error_set(errp, QERR_BLOCK_JOB_PAUSED, device);
return;
}
trace_qmp_block_job_cancel(job);
block_job_cancel(job);
}
void qmp_block_job_pause(const char *device, Error **errp)
{
BlockJob *job = find_block_job(device);
if (!job) {
error_set(errp, QERR_BLOCK_JOB_NOT_ACTIVE, device);
return;
}
trace_qmp_block_job_pause(job);
block_job_pause(job);
}
void qmp_block_job_resume(const char *device, Error **errp)
{
BlockJob *job = find_block_job(device);
if (!job) {
error_set(errp, QERR_BLOCK_JOB_NOT_ACTIVE, device);
return;
}
trace_qmp_block_job_resume(job);
block_job_resume(job);
}
void qmp_block_job_complete(const char *device, Error **errp)
{
BlockJob *job = find_block_job(device);
if (!job) {
error_set(errp, QERR_BLOCK_JOB_NOT_ACTIVE, device);
return;
}
trace_qmp_block_job_complete(job);
block_job_complete(job, errp);
}
static void do_qmp_query_block_jobs_one(void *opaque, BlockDriverState *bs)
{
BlockJobInfoList **prev = opaque;
BlockJob *job = bs->job;
if (job) {
BlockJobInfoList *elem = g_new0(BlockJobInfoList, 1);
elem->value = block_job_query(bs->job);
(*prev)->next = elem;
*prev = elem;
}
}
BlockJobInfoList *qmp_query_block_jobs(Error **errp)
{
/* Dummy is a fake list element for holding the head pointer */
BlockJobInfoList dummy = {};
BlockJobInfoList *prev = &dummy;
bdrv_iterate(do_qmp_query_block_jobs_one, &prev);
return dummy.next;
}