haraldwolff/qemu-patch-raspberry4
1
0
Fork 0
Code Issues Pull requests Packages Projects Releases Wiki Activity
qemu-patch-raspberry4/block/backup.c
John Snow 7e30dd618e block/backup: teach TOP to never copy unallocated regions 
Presently, If sync=TOP is selected, we mark the entire bitmap as dirty.
In the write notifier handler, we dutifully copy out such regions.

Fix this in three parts:

1. Mark the bitmap as being initialized before the first yield.
2. After the first yield but before the backup loop, interrogate the
allocation status asynchronously and initialize the bitmap.
3. Teach the write notifier to interrogate allocation status if it is
invoked during bitmap initialization.

As an effect of this patch, the job progress for TOP backups
now behaves like this:

- total progress starts at bdrv_length.
- As allocation status is interrogated, total progress decreases.
- As blocks are copied, current progress increases.

Taken together, the floor and ceiling move to meet each other.


Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20190716000117.25219-10-jsnow@redhat.com
[Remove ret = -ECANCELED change. --js]
[Squash in conflict resolution based on Max's patch --js]
Message-id: c8b0ab36-79c8-0b4b-3193-4e12ed8c848b@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
2019-08-16 16:28:03 -04:00

799 lines
25 KiB
C
Raw Blame History

/*
* QEMU backup
*
* Copyright (C) 2013 Proxmox Server Solutions
*
* Authors:
* Dietmar Maurer (dietmar@proxmox.com)
*
* 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 "qemu/osdep.h"
#include "trace.h"
#include "block/block.h"
#include "block/block_int.h"
#include "block/blockjob_int.h"
#include "block/block_backup.h"
#include "qapi/error.h"
#include "qapi/qmp/qerror.h"
#include "qemu/ratelimit.h"
#include "qemu/cutils.h"
#include "sysemu/block-backend.h"
#include "qemu/bitmap.h"
#include "qemu/error-report.h"
#define BACKUP_CLUSTER_SIZE_DEFAULT (1 << 16)
typedef struct CowRequest {
int64_t start_byte;
int64_t end_byte;
QLIST_ENTRY(CowRequest) list;
CoQueue wait_queue; /* coroutines blocked on this request */
} CowRequest;
typedef struct BackupBlockJob {
BlockJob common;
BlockBackend *target;
BdrvDirtyBitmap *sync_bitmap;
BdrvDirtyBitmap *copy_bitmap;
MirrorSyncMode sync_mode;
BitmapSyncMode bitmap_mode;
BlockdevOnError on_source_error;
BlockdevOnError on_target_error;
CoRwlock flush_rwlock;
uint64_t len;
uint64_t bytes_read;
int64_t cluster_size;
bool compress;
NotifierWithReturn before_write;
QLIST_HEAD(, CowRequest) inflight_reqs;
bool use_copy_range;
int64_t copy_range_size;
bool serialize_target_writes;
bool initializing_bitmap;
} BackupBlockJob;
static const BlockJobDriver backup_job_driver;
/* See if in-flight requests overlap and wait for them to complete */
static void coroutine_fn wait_for_overlapping_requests(BackupBlockJob *job,
int64_t start,
int64_t end)
{
CowRequest *req;
bool retry;
do {
retry = false;
QLIST_FOREACH(req, &job->inflight_reqs, list) {
if (end > req->start_byte && start < req->end_byte) {
qemu_co_queue_wait(&req->wait_queue, NULL);
retry = true;
break;
}
}
} while (retry);
}
/* Keep track of an in-flight request */
static void cow_request_begin(CowRequest *req, BackupBlockJob *job,
int64_t start, int64_t end)
{
req->start_byte = start;
req->end_byte = end;
qemu_co_queue_init(&req->wait_queue);
QLIST_INSERT_HEAD(&job->inflight_reqs, req, list);
}
/* Forget about a completed request */
static void cow_request_end(CowRequest *req)
{
QLIST_REMOVE(req, list);
qemu_co_queue_restart_all(&req->wait_queue);
}
/* Copy range to target with a bounce buffer and return the bytes copied. If
* error occurred, return a negative error number */
static int coroutine_fn backup_cow_with_bounce_buffer(BackupBlockJob *job,
int64_t start,
int64_t end,
bool is_write_notifier,
bool *error_is_read,
void **bounce_buffer)
{
int ret;
BlockBackend *blk = job->common.blk;
int nbytes;
int read_flags = is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0;
int write_flags = job->serialize_target_writes ? BDRV_REQ_SERIALISING : 0;
assert(QEMU_IS_ALIGNED(start, job->cluster_size));
bdrv_reset_dirty_bitmap(job->copy_bitmap, start, job->cluster_size);
nbytes = MIN(job->cluster_size, job->len - start);
if (!*bounce_buffer) {
*bounce_buffer = blk_blockalign(blk, job->cluster_size);
}
ret = blk_co_pread(blk, start, nbytes, *bounce_buffer, read_flags);
if (ret < 0) {
trace_backup_do_cow_read_fail(job, start, ret);
if (error_is_read) {
*error_is_read = true;
}
goto fail;
}
if (buffer_is_zero(*bounce_buffer, nbytes)) {
ret = blk_co_pwrite_zeroes(job->target, start,
nbytes, write_flags | BDRV_REQ_MAY_UNMAP);
} else {
ret = blk_co_pwrite(job->target, start,
nbytes, *bounce_buffer, write_flags |
(job->compress ? BDRV_REQ_WRITE_COMPRESSED : 0));
}
if (ret < 0) {
trace_backup_do_cow_write_fail(job, start, ret);
if (error_is_read) {
*error_is_read = false;
}
goto fail;
}
return nbytes;
fail:
bdrv_set_dirty_bitmap(job->copy_bitmap, start, job->cluster_size);
return ret;
}
/* Copy range to target and return the bytes copied. If error occurred, return a
* negative error number. */
static int coroutine_fn backup_cow_with_offload(BackupBlockJob *job,
int64_t start,
int64_t end,
bool is_write_notifier)
{
int ret;
int nr_clusters;
BlockBackend *blk = job->common.blk;
int nbytes;
int read_flags = is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0;
int write_flags = job->serialize_target_writes ? BDRV_REQ_SERIALISING : 0;
assert(QEMU_IS_ALIGNED(job->copy_range_size, job->cluster_size));
assert(QEMU_IS_ALIGNED(start, job->cluster_size));
nbytes = MIN(job->copy_range_size, end - start);
nr_clusters = DIV_ROUND_UP(nbytes, job->cluster_size);
bdrv_reset_dirty_bitmap(job->copy_bitmap, start,
job->cluster_size * nr_clusters);
ret = blk_co_copy_range(blk, start, job->target, start, nbytes,
read_flags, write_flags);
if (ret < 0) {
trace_backup_do_cow_copy_range_fail(job, start, ret);
bdrv_set_dirty_bitmap(job->copy_bitmap, start,
job->cluster_size * nr_clusters);
return ret;
}
return nbytes;
}
/*
* Check if the cluster starting at offset is allocated or not.
* return via pnum the number of contiguous clusters sharing this allocation.
*/
static int backup_is_cluster_allocated(BackupBlockJob *s, int64_t offset,
int64_t *pnum)
{
BlockDriverState *bs = blk_bs(s->common.blk);
int64_t count, total_count = 0;
int64_t bytes = s->len - offset;
int ret;
assert(QEMU_IS_ALIGNED(offset, s->cluster_size));
while (true) {
ret = bdrv_is_allocated(bs, offset, bytes, &count);
if (ret < 0) {
return ret;
}
total_count += count;
if (ret || count == 0) {
/*
* ret: partial segment(s) are considered allocated.
* otherwise: unallocated tail is treated as an entire segment.
*/
*pnum = DIV_ROUND_UP(total_count, s->cluster_size);
return ret;
}
/* Unallocated segment(s) with uncertain following segment(s) */
if (total_count >= s->cluster_size) {
*pnum = total_count / s->cluster_size;
return 0;
}
offset += count;
bytes -= count;
}
}
/**
* Reset bits in copy_bitmap starting at offset if they represent unallocated
* data in the image. May reset subsequent contiguous bits.
* @return 0 when the cluster at @offset was unallocated,
* 1 otherwise, and -ret on error.
*/
static int64_t backup_bitmap_reset_unallocated(BackupBlockJob *s,
int64_t offset, int64_t *count)
{
int ret;
int64_t clusters, bytes, estimate;
ret = backup_is_cluster_allocated(s, offset, &clusters);
if (ret < 0) {
return ret;
}
bytes = clusters * s->cluster_size;
if (!ret) {
bdrv_reset_dirty_bitmap(s->copy_bitmap, offset, bytes);
estimate = bdrv_get_dirty_count(s->copy_bitmap);
job_progress_set_remaining(&s->common.job, estimate);
}
*count = bytes;
return ret;
}
static int coroutine_fn backup_do_cow(BackupBlockJob *job,
int64_t offset, uint64_t bytes,
bool *error_is_read,
bool is_write_notifier)
{
CowRequest cow_request;
int ret = 0;
int64_t start, end; /* bytes */
void *bounce_buffer = NULL;
int64_t status_bytes;
qemu_co_rwlock_rdlock(&job->flush_rwlock);
start = QEMU_ALIGN_DOWN(offset, job->cluster_size);
end = QEMU_ALIGN_UP(bytes + offset, job->cluster_size);
trace_backup_do_cow_enter(job, start, offset, bytes);
wait_for_overlapping_requests(job, start, end);
cow_request_begin(&cow_request, job, start, end);
while (start < end) {
int64_t dirty_end;
if (!bdrv_dirty_bitmap_get(job->copy_bitmap, start)) {
trace_backup_do_cow_skip(job, start);
start += job->cluster_size;
continue; /* already copied */
}
dirty_end = bdrv_dirty_bitmap_next_zero(job->copy_bitmap, start,
(end - start));
if (dirty_end < 0) {
dirty_end = end;
}
if (job->initializing_bitmap) {
ret = backup_bitmap_reset_unallocated(job, start, &status_bytes);
if (ret == 0) {
trace_backup_do_cow_skip_range(job, start, status_bytes);
start += status_bytes;
continue;
}
/* Clamp to known allocated region */
dirty_end = MIN(dirty_end, start + status_bytes);
}
trace_backup_do_cow_process(job, start);
if (job->use_copy_range) {
ret = backup_cow_with_offload(job, start, dirty_end,
is_write_notifier);
if (ret < 0) {
job->use_copy_range = false;
}
}
if (!job->use_copy_range) {
ret = backup_cow_with_bounce_buffer(job, start, dirty_end,
is_write_notifier,
error_is_read, &bounce_buffer);
}
if (ret < 0) {
break;
}
/* Publish progress, guest I/O counts as progress too. Note that the
* offset field is an opaque progress value, it is not a disk offset.
*/
start += ret;
job->bytes_read += ret;
job_progress_update(&job->common.job, ret);
ret = 0;
}
if (bounce_buffer) {
qemu_vfree(bounce_buffer);
}
cow_request_end(&cow_request);
trace_backup_do_cow_return(job, offset, bytes, ret);
qemu_co_rwlock_unlock(&job->flush_rwlock);
return ret;
}
static int coroutine_fn backup_before_write_notify(
NotifierWithReturn *notifier,
void *opaque)
{
BackupBlockJob *job = container_of(notifier, BackupBlockJob, before_write);
BdrvTrackedRequest *req = opaque;
assert(req->bs == blk_bs(job->common.blk));
assert(QEMU_IS_ALIGNED(req->offset, BDRV_SECTOR_SIZE));
assert(QEMU_IS_ALIGNED(req->bytes, BDRV_SECTOR_SIZE));
return backup_do_cow(job, req->offset, req->bytes, NULL, true);
}
static void backup_cleanup_sync_bitmap(BackupBlockJob *job, int ret)
{
BdrvDirtyBitmap *bm;
BlockDriverState *bs = blk_bs(job->common.blk);
bool sync = (((ret == 0) || (job->bitmap_mode == BITMAP_SYNC_MODE_ALWAYS)) \
&& (job->bitmap_mode != BITMAP_SYNC_MODE_NEVER));
if (sync) {
/*
* We succeeded, or we always intended to sync the bitmap.
* Delete this bitmap and install the child.
*/
bm = bdrv_dirty_bitmap_abdicate(bs, job->sync_bitmap, NULL);
} else {
/*
* We failed, or we never intended to sync the bitmap anyway.
* Merge the successor back into the parent, keeping all data.
*/
bm = bdrv_reclaim_dirty_bitmap(bs, job->sync_bitmap, NULL);
}
assert(bm);
if (ret < 0 && job->bitmap_mode == BITMAP_SYNC_MODE_ALWAYS) {
/* If we failed and synced, merge in the bits we didn't copy: */
bdrv_dirty_bitmap_merge_internal(bm, job->copy_bitmap,
NULL, true);
}
}
static void backup_commit(Job *job)
{
BackupBlockJob *s = container_of(job, BackupBlockJob, common.job);
if (s->sync_bitmap) {
backup_cleanup_sync_bitmap(s, 0);
}
}
static void backup_abort(Job *job)
{
BackupBlockJob *s = container_of(job, BackupBlockJob, common.job);
if (s->sync_bitmap) {
backup_cleanup_sync_bitmap(s, -1);
}
}
static void backup_clean(Job *job)
{
BackupBlockJob *s = container_of(job, BackupBlockJob, common.job);
BlockDriverState *bs = blk_bs(s->common.blk);
if (s->copy_bitmap) {
bdrv_release_dirty_bitmap(bs, s->copy_bitmap);
s->copy_bitmap = NULL;
}
assert(s->target);
blk_unref(s->target);
s->target = NULL;
}
void backup_do_checkpoint(BlockJob *job, Error **errp)
{
BackupBlockJob *backup_job = container_of(job, BackupBlockJob, common);
assert(block_job_driver(job) == &backup_job_driver);
if (backup_job->sync_mode != MIRROR_SYNC_MODE_NONE) {
error_setg(errp, "The backup job only supports block checkpoint in"
" sync=none mode");
return;
}
bdrv_set_dirty_bitmap(backup_job->copy_bitmap, 0, backup_job->len);
}
static void backup_drain(BlockJob *job)
{
BackupBlockJob *s = container_of(job, BackupBlockJob, common);
/* Need to keep a reference in case blk_drain triggers execution
* of backup_complete...
*/
if (s->target) {
BlockBackend *target = s->target;
blk_ref(target);
blk_drain(target);
blk_unref(target);
}
}
static BlockErrorAction backup_error_action(BackupBlockJob *job,
bool read, int error)
{
if (read) {
return block_job_error_action(&job->common, job->on_source_error,
true, error);
} else {
return block_job_error_action(&job->common, job->on_target_error,
false, error);
}
}
static bool coroutine_fn yield_and_check(BackupBlockJob *job)
{
uint64_t delay_ns;
if (job_is_cancelled(&job->common.job)) {
return true;
}
/* We need to yield even for delay_ns = 0 so that bdrv_drain_all() can
* return. Without a yield, the VM would not reboot. */
delay_ns = block_job_ratelimit_get_delay(&job->common, job->bytes_read);
job->bytes_read = 0;
job_sleep_ns(&job->common.job, delay_ns);
if (job_is_cancelled(&job->common.job)) {
return true;
}
return false;
}
static int coroutine_fn backup_loop(BackupBlockJob *job)
{
bool error_is_read;
int64_t offset;
BdrvDirtyBitmapIter *bdbi;
int ret = 0;
bdbi = bdrv_dirty_iter_new(job->copy_bitmap);
while ((offset = bdrv_dirty_iter_next(bdbi)) != -1) {
do {
if (yield_and_check(job)) {
goto out;
}
ret = backup_do_cow(job, offset,
job->cluster_size, &error_is_read, false);
if (ret < 0 && backup_error_action(job, error_is_read, -ret) ==
BLOCK_ERROR_ACTION_REPORT)
{
goto out;
}
} while (ret < 0);
}
out:
bdrv_dirty_iter_free(bdbi);
return ret;
}
static void backup_init_copy_bitmap(BackupBlockJob *job)
{
bool ret;
uint64_t estimate;
if (job->sync_mode == MIRROR_SYNC_MODE_BITMAP) {
ret = bdrv_dirty_bitmap_merge_internal(job->copy_bitmap,
job->sync_bitmap,
NULL, true);
assert(ret);
} else {
if (job->sync_mode == MIRROR_SYNC_MODE_TOP) {
/*
* We can't hog the coroutine to initialize this thoroughly.
* Set a flag and resume work when we are able to yield safely.
*/
job->initializing_bitmap = true;
}
bdrv_set_dirty_bitmap(job->copy_bitmap, 0, job->len);
}
estimate = bdrv_get_dirty_count(job->copy_bitmap);
job_progress_set_remaining(&job->common.job, estimate);
}
static int coroutine_fn backup_run(Job *job, Error **errp)
{
BackupBlockJob *s = container_of(job, BackupBlockJob, common.job);
BlockDriverState *bs = blk_bs(s->common.blk);
int ret = 0;
QLIST_INIT(&s->inflight_reqs);
qemu_co_rwlock_init(&s->flush_rwlock);
backup_init_copy_bitmap(s);
s->before_write.notify = backup_before_write_notify;
bdrv_add_before_write_notifier(bs, &s->before_write);
if (s->sync_mode == MIRROR_SYNC_MODE_TOP) {
int64_t offset = 0;
int64_t count;
for (offset = 0; offset < s->len; ) {
if (yield_and_check(s)) {
ret = -ECANCELED;
goto out;
}
ret = backup_bitmap_reset_unallocated(s, offset, &count);
if (ret < 0) {
goto out;
}
offset += count;
}
s->initializing_bitmap = false;
}
if (s->sync_mode == MIRROR_SYNC_MODE_NONE) {
/* All bits are set in copy_bitmap to allow any cluster to be copied.
* This does not actually require them to be copied. */
while (!job_is_cancelled(job)) {
/* Yield until the job is cancelled. We just let our before_write
* notify callback service CoW requests. */
job_yield(job);
}
} else {
ret = backup_loop(s);
}
out:
notifier_with_return_remove(&s->before_write);
/* wait until pending backup_do_cow() calls have completed */
qemu_co_rwlock_wrlock(&s->flush_rwlock);
qemu_co_rwlock_unlock(&s->flush_rwlock);
return ret;
}
static const BlockJobDriver backup_job_driver = {
.job_driver = {
.instance_size = sizeof(BackupBlockJob),
.job_type = JOB_TYPE_BACKUP,
.free = block_job_free,
.user_resume = block_job_user_resume,
.drain = block_job_drain,
.run = backup_run,
.commit = backup_commit,
.abort = backup_abort,
.clean = backup_clean,
},
.drain = backup_drain,
};
static int64_t backup_calculate_cluster_size(BlockDriverState *target,
Error **errp)
{
int ret;
BlockDriverInfo bdi;
/*
* If there is no backing file on the target, we cannot rely on COW if our
* backup cluster size is smaller than the target cluster size. Even for
* targets with a backing file, try to avoid COW if possible.
*/
ret = bdrv_get_info(target, &bdi);
if (ret == -ENOTSUP && !target->backing) {
/* Cluster size is not defined */
warn_report("The target block device doesn't provide "
"information about the block size and it doesn't have a "
"backing file. The default block size of %u bytes is "
"used. If the actual block size of the target exceeds "
"this default, the backup may be unusable",
BACKUP_CLUSTER_SIZE_DEFAULT);
return BACKUP_CLUSTER_SIZE_DEFAULT;
} else if (ret < 0 && !target->backing) {
error_setg_errno(errp, -ret,
"Couldn't determine the cluster size of the target image, "
"which has no backing file");
error_append_hint(errp,
"Aborting, since this may create an unusable destination image\n");
return ret;
} else if (ret < 0 && target->backing) {
/* Not fatal; just trudge on ahead. */
return BACKUP_CLUSTER_SIZE_DEFAULT;
}
return MAX(BACKUP_CLUSTER_SIZE_DEFAULT, bdi.cluster_size);
}
BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
BlockDriverState *target, int64_t speed,
MirrorSyncMode sync_mode, BdrvDirtyBitmap *sync_bitmap,
BitmapSyncMode bitmap_mode,
bool compress,
BlockdevOnError on_source_error,
BlockdevOnError on_target_error,
int creation_flags,
BlockCompletionFunc *cb, void *opaque,
JobTxn *txn, Error **errp)
{
int64_t len;
BackupBlockJob *job = NULL;
int ret;
int64_t cluster_size;
BdrvDirtyBitmap *copy_bitmap = NULL;
assert(bs);
assert(target);
/* QMP interface protects us from these cases */
assert(sync_mode != MIRROR_SYNC_MODE_INCREMENTAL);
assert(sync_bitmap || sync_mode != MIRROR_SYNC_MODE_BITMAP);
if (bs == target) {
error_setg(errp, "Source and target cannot be the same");
return NULL;
}
if (!bdrv_is_inserted(bs)) {
error_setg(errp, "Device is not inserted: %s",
bdrv_get_device_name(bs));
return NULL;
}
if (!bdrv_is_inserted(target)) {
error_setg(errp, "Device is not inserted: %s",
bdrv_get_device_name(target));
return NULL;
}
if (compress && target->drv->bdrv_co_pwritev_compressed == NULL) {
error_setg(errp, "Compression is not supported for this drive %s",
bdrv_get_device_name(target));
return NULL;
}
if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP_SOURCE, errp)) {
return NULL;
}
if (bdrv_op_is_blocked(target, BLOCK_OP_TYPE_BACKUP_TARGET, errp)) {
return NULL;
}
if (sync_mode == MIRROR_SYNC_MODE_BITMAP) {
/* If we need to write to this bitmap, check that we can: */
if (bitmap_mode != BITMAP_SYNC_MODE_NEVER &&
bdrv_dirty_bitmap_check(sync_bitmap, BDRV_BITMAP_DEFAULT, errp)) {
return NULL;
}
/* Create a new bitmap, and freeze/disable this one. */
if (bdrv_dirty_bitmap_create_successor(bs, sync_bitmap, errp) < 0) {
return NULL;
}
} else if (sync_bitmap) {
error_setg(errp,
"a bitmap was given to backup_job_create, "
"but it received an incompatible sync_mode (%s)",
MirrorSyncMode_str(sync_mode));
return NULL;
}
len = bdrv_getlength(bs);
if (len < 0) {
error_setg_errno(errp, -len, "unable to get length for '%s'",
bdrv_get_device_name(bs));
goto error;
}
cluster_size = backup_calculate_cluster_size(target, errp);
if (cluster_size < 0) {
goto error;
}
copy_bitmap = bdrv_create_dirty_bitmap(bs, cluster_size, NULL, errp);
if (!copy_bitmap) {
goto error;
}
bdrv_disable_dirty_bitmap(copy_bitmap);
/* job->len is fixed, so we can't allow resize */
job = block_job_create(job_id, &backup_job_driver, txn, bs,
BLK_PERM_CONSISTENT_READ,
BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE |
BLK_PERM_WRITE_UNCHANGED | BLK_PERM_GRAPH_MOD,
speed, creation_flags, cb, opaque, errp);
if (!job) {
goto error;
}
/* The target must match the source in size, so no resize here either */
job->target = blk_new(job->common.job.aio_context,
BLK_PERM_WRITE,
BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE |
BLK_PERM_WRITE_UNCHANGED | BLK_PERM_GRAPH_MOD);
ret = blk_insert_bs(job->target, target, errp);
if (ret < 0) {
goto error;
}
blk_set_disable_request_queuing(job->target, true);
job->on_source_error = on_source_error;
job->on_target_error = on_target_error;
job->sync_mode = sync_mode;
job->sync_bitmap = sync_bitmap;
job->bitmap_mode = bitmap_mode;
job->compress = compress;
/* Detect image-fleecing (and similar) schemes */
job->serialize_target_writes = bdrv_chain_contains(target, bs);
job->cluster_size = cluster_size;
job->copy_bitmap = copy_bitmap;
copy_bitmap = NULL;
job->use_copy_range = !compress; /* compression isn't supported for it */
job->copy_range_size = MIN_NON_ZERO(blk_get_max_transfer(job->common.blk),
blk_get_max_transfer(job->target));
job->copy_range_size = MAX(job->cluster_size,
QEMU_ALIGN_UP(job->copy_range_size,
job->cluster_size));
/* Required permissions are already taken with target's blk_new() */
block_job_add_bdrv(&job->common, "target", target, 0, BLK_PERM_ALL,
&error_abort);
job->len = len;
return &job->common;
error:
if (copy_bitmap) {
assert(!job || !job->copy_bitmap);
bdrv_release_dirty_bitmap(bs, copy_bitmap);
}
if (sync_bitmap) {
bdrv_reclaim_dirty_bitmap(bs, sync_bitmap, NULL);
}
if (job) {
backup_clean(&job->common.job);
job_early_fail(&job->common.job);
}
return NULL;
}
Reference in a new issue View git blame Copy permalink