#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;
- /* bitmap for sync=incremental */
+
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;
- HBitmap *copy_bitmap;
bool use_copy_range;
int64_t copy_range_size;
+
+ BdrvRequestFlags write_flags;
+ bool initializing_bitmap;
} BackupBlockJob;
static const BlockJobDriver backup_job_driver;
}
/* Copy range to target with a bounce buffer and return the bytes copied. If
- * error occured, return a negative error number */
+ * error occurred, return a negative error number */
static int coroutine_fn backup_cow_with_bounce_buffer(BackupBlockJob *job,
int64_t start,
int64_t end,
void **bounce_buffer)
{
int ret;
- struct iovec iov;
- QEMUIOVector qiov;
BlockBackend *blk = job->common.blk;
int nbytes;
+ int read_flags = is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0;
- hbitmap_reset(job->copy_bitmap, start / job->cluster_size, 1);
+ 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);
}
- iov.iov_base = *bounce_buffer;
- iov.iov_len = nbytes;
- qemu_iovec_init_external(&qiov, &iov, 1);
- ret = blk_co_preadv(blk, start, qiov.size, &qiov,
- is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0);
+ 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) {
goto fail;
}
- if (qemu_iovec_is_zero(&qiov)) {
- ret = blk_co_pwrite_zeroes(job->target, start,
- qiov.size, BDRV_REQ_MAY_UNMAP);
- } else {
- ret = blk_co_pwritev(job->target, start,
- qiov.size, &qiov,
- job->compress ? BDRV_REQ_WRITE_COMPRESSED : 0);
- }
+ ret = blk_co_pwrite(job->target, start, nbytes, *bounce_buffer,
+ job->write_flags);
if (ret < 0) {
trace_backup_do_cow_write_fail(job, start, ret);
if (error_is_read) {
return nbytes;
fail:
- hbitmap_set(job->copy_bitmap, start / job->cluster_size, 1);
+ bdrv_set_dirty_bitmap(job->copy_bitmap, start, job->cluster_size);
return ret;
}
-/* Copy range to target and return the bytes copied. If error occured, return a
+/* 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,
int nr_clusters;
BlockBackend *blk = job->common.blk;
int nbytes;
+ int read_flags = is_write_notifier ? BDRV_REQ_NO_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);
- hbitmap_reset(job->copy_bitmap, start / job->cluster_size,
- nr_clusters);
+ bdrv_reset_dirty_bitmap(job->copy_bitmap, start,
+ job->cluster_size * nr_clusters);
ret = blk_co_copy_range(blk, start, job->target, start, nbytes,
- is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0);
+ read_flags, job->write_flags);
if (ret < 0) {
trace_backup_do_cow_copy_range_fail(job, start, ret);
- hbitmap_set(job->copy_bitmap, start / job->cluster_size,
- nr_clusters);
+ 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,
int ret = 0;
int64_t start, end; /* bytes */
void *bounce_buffer = NULL;
+ int64_t status_bytes;
qemu_co_rwlock_rdlock(&job->flush_rwlock);
cow_request_begin(&cow_request, job, start, end);
while (start < end) {
- if (!hbitmap_get(job->copy_bitmap, start / job->cluster_size)) {
+ 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, end, is_write_notifier);
+ 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, end, is_write_notifier,
+ ret = backup_cow_with_bounce_buffer(job, start, dirty_end,
+ is_write_notifier,
error_is_read, &bounce_buffer);
}
if (ret < 0) {
{
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 (ret < 0) {
- /* Merge the successor back into the parent, delete nothing. */
- bm = bdrv_reclaim_dirty_bitmap(bs, job->sync_bitmap, NULL);
- assert(bm);
- } else {
- /* Everything is fine, delete this bitmap and install the backup. */
+ 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);
- assert(bm);
+ } 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_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;
}
-static void backup_attached_aio_context(BlockJob *job, AioContext *aio_context)
-{
- BackupBlockJob *s = container_of(job, BackupBlockJob, common);
-
- blk_set_aio_context(s->target, aio_context);
-}
-
void backup_do_checkpoint(BlockJob *job, Error **errp)
{
BackupBlockJob *backup_job = container_of(job, BackupBlockJob, common);
- int64_t len;
assert(block_job_driver(job) == &backup_job_driver);
return;
}
- len = DIV_ROUND_UP(backup_job->len, backup_job->cluster_size);
- hbitmap_set(backup_job->copy_bitmap, 0, len);
-}
-
-void backup_wait_for_overlapping_requests(BlockJob *job, int64_t offset,
- uint64_t bytes)
-{
- BackupBlockJob *backup_job = container_of(job, BackupBlockJob, common);
- int64_t start, end;
-
- assert(block_job_driver(job) == &backup_job_driver);
-
- start = QEMU_ALIGN_DOWN(offset, backup_job->cluster_size);
- end = QEMU_ALIGN_UP(offset + bytes, backup_job->cluster_size);
- wait_for_overlapping_requests(backup_job, start, end);
-}
-
-void backup_cow_request_begin(CowRequest *req, BlockJob *job,
- int64_t offset, uint64_t bytes)
-{
- BackupBlockJob *backup_job = container_of(job, BackupBlockJob, common);
- int64_t start, end;
-
- assert(block_job_driver(job) == &backup_job_driver);
-
- start = QEMU_ALIGN_DOWN(offset, backup_job->cluster_size);
- end = QEMU_ALIGN_UP(offset + bytes, backup_job->cluster_size);
- cow_request_begin(req, backup_job, start, end);
-}
-
-void backup_cow_request_end(CowRequest *req)
-{
- cow_request_end(req);
+ bdrv_set_dirty_bitmap(backup_job->copy_bitmap, 0, backup_job->len);
}
static void backup_drain(BlockJob *job)
}
}
-typedef struct {
- int ret;
-} BackupCompleteData;
-
-static void backup_complete(Job *job, void *opaque)
-{
- BackupCompleteData *data = opaque;
-
- job_completed(job, data->ret, NULL);
- g_free(data);
-}
-
static bool coroutine_fn yield_and_check(BackupBlockJob *job)
{
uint64_t delay_ns;
return false;
}
-static int coroutine_fn backup_run_incremental(BackupBlockJob *job)
+static int coroutine_fn backup_loop(BackupBlockJob *job)
{
- int ret;
bool error_is_read;
- int64_t cluster;
- HBitmapIter hbi;
+ int64_t offset;
+ BdrvDirtyBitmapIter *bdbi;
+ int ret = 0;
- hbitmap_iter_init(&hbi, job->copy_bitmap, 0);
- while ((cluster = hbitmap_iter_next(&hbi, true)) != -1) {
+ bdbi = bdrv_dirty_iter_new(job->copy_bitmap);
+ while ((offset = bdrv_dirty_iter_next(bdbi)) != -1) {
do {
if (yield_and_check(job)) {
- return 0;
+ goto out;
}
- ret = backup_do_cow(job, cluster * job->cluster_size,
+ 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)
{
- return ret;
+ goto out;
}
} while (ret < 0);
}
- return 0;
+ out:
+ bdrv_dirty_iter_free(bdbi);
+ return ret;
}
-/* init copy_bitmap from sync_bitmap */
-static void backup_incremental_init_copy_bitmap(BackupBlockJob *job)
+static void backup_init_copy_bitmap(BackupBlockJob *job)
{
- BdrvDirtyBitmapIter *dbi;
- int64_t offset;
- int64_t end = DIV_ROUND_UP(bdrv_dirty_bitmap_size(job->sync_bitmap),
- job->cluster_size);
-
- dbi = bdrv_dirty_iter_new(job->sync_bitmap);
- while ((offset = bdrv_dirty_iter_next(dbi)) != -1) {
- int64_t cluster = offset / job->cluster_size;
- int64_t next_cluster;
-
- offset += bdrv_dirty_bitmap_granularity(job->sync_bitmap);
- if (offset >= bdrv_dirty_bitmap_size(job->sync_bitmap)) {
- hbitmap_set(job->copy_bitmap, cluster, end - cluster);
- break;
- }
-
- offset = bdrv_dirty_bitmap_next_zero(job->sync_bitmap, offset);
- if (offset == -1) {
- hbitmap_set(job->copy_bitmap, cluster, end - cluster);
- break;
- }
-
- next_cluster = DIV_ROUND_UP(offset, job->cluster_size);
- hbitmap_set(job->copy_bitmap, cluster, next_cluster - cluster);
- if (next_cluster >= end) {
- break;
+ 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_iter(dbi, next_cluster * job->cluster_size);
+ bdrv_set_dirty_bitmap(job->copy_bitmap, 0, job->len);
}
- /* TODO job_progress_set_remaining() would make more sense */
- job_progress_update(&job->common.job,
- job->len - hbitmap_count(job->copy_bitmap) * job->cluster_size);
-
- bdrv_dirty_iter_free(dbi);
+ estimate = bdrv_get_dirty_count(job->copy_bitmap);
+ job_progress_set_remaining(&job->common.job, estimate);
}
-static void coroutine_fn backup_run(void *opaque)
+static int coroutine_fn backup_run(Job *job, Error **errp)
{
- BackupBlockJob *job = opaque;
- BackupCompleteData *data;
- BlockDriverState *bs = blk_bs(job->common.blk);
- int64_t offset, nb_clusters;
+ BackupBlockJob *s = container_of(job, BackupBlockJob, common.job);
+ BlockDriverState *bs = blk_bs(s->common.blk);
int ret = 0;
- QLIST_INIT(&job->inflight_reqs);
- qemu_co_rwlock_init(&job->flush_rwlock);
+ QLIST_INIT(&s->inflight_reqs);
+ qemu_co_rwlock_init(&s->flush_rwlock);
- nb_clusters = DIV_ROUND_UP(job->len, job->cluster_size);
- job_progress_set_remaining(&job->common.job, job->len);
+ backup_init_copy_bitmap(s);
- job->copy_bitmap = hbitmap_alloc(nb_clusters, 0);
- if (job->sync_mode == MIRROR_SYNC_MODE_INCREMENTAL) {
- backup_incremental_init_copy_bitmap(job);
- } else {
- hbitmap_set(job->copy_bitmap, 0, nb_clusters);
- }
+ 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;
- job->before_write.notify = backup_before_write_notify;
- bdrv_add_before_write_notifier(bs, &job->before_write);
+ 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 (job->sync_mode == MIRROR_SYNC_MODE_NONE) {
+ 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->common.job)) {
+ 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->common.job);
+ job_yield(job);
}
- } else if (job->sync_mode == MIRROR_SYNC_MODE_INCREMENTAL) {
- ret = backup_run_incremental(job);
} else {
- /* Both FULL and TOP SYNC_MODE's require copying.. */
- for (offset = 0; offset < job->len;
- offset += job->cluster_size) {
- bool error_is_read;
- int alloced = 0;
-
- if (yield_and_check(job)) {
- break;
- }
-
- if (job->sync_mode == MIRROR_SYNC_MODE_TOP) {
- int i;
- int64_t n;
-
- /* Check to see if these blocks are already in the
- * backing file. */
-
- for (i = 0; i < job->cluster_size;) {
- /* bdrv_is_allocated() only returns true/false based
- * on the first set of sectors it comes across that
- * are are all in the same state.
- * For that reason we must verify each sector in the
- * backup cluster length. We end up copying more than
- * needed but at some point that is always the case. */
- alloced =
- bdrv_is_allocated(bs, offset + i,
- job->cluster_size - i, &n);
- i += n;
-
- if (alloced || n == 0) {
- break;
- }
- }
-
- /* If the above loop never found any sectors that are in
- * the topmost image, skip this backup. */
- if (alloced == 0) {
- continue;
- }
- }
- /* FULL sync mode we copy the whole drive. */
- if (alloced < 0) {
- ret = alloced;
- } else {
- ret = backup_do_cow(job, offset, job->cluster_size,
- &error_is_read, false);
- }
- if (ret < 0) {
- /* Depending on error action, fail now or retry cluster */
- BlockErrorAction action =
- backup_error_action(job, error_is_read, -ret);
- if (action == BLOCK_ERROR_ACTION_REPORT) {
- break;
- } else {
- offset -= job->cluster_size;
- continue;
- }
- }
- }
+ ret = backup_loop(s);
}
- notifier_with_return_remove(&job->before_write);
+ out:
+ notifier_with_return_remove(&s->before_write);
/* wait until pending backup_do_cow() calls have completed */
- qemu_co_rwlock_wrlock(&job->flush_rwlock);
- qemu_co_rwlock_unlock(&job->flush_rwlock);
- hbitmap_free(job->copy_bitmap);
+ qemu_co_rwlock_wrlock(&s->flush_rwlock);
+ qemu_co_rwlock_unlock(&s->flush_rwlock);
- data = g_malloc(sizeof(*data));
- data->ret = ret;
- job_defer_to_main_loop(&job->common.job, backup_complete, data);
+ return ret;
}
static const BlockJobDriver backup_job_driver = {
.free = block_job_free,
.user_resume = block_job_user_resume,
.drain = block_job_drain,
- .start = backup_run,
+ .run = backup_run,
.commit = backup_commit,
.abort = backup_abort,
.clean = backup_clean,
},
- .attached_aio_context = backup_attached_aio_context,
.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,
JobTxn *txn, Error **errp)
{
int64_t len;
- BlockDriverInfo bdi;
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;
return NULL;
}
- if (sync_mode == MIRROR_SYNC_MODE_INCREMENTAL) {
- if (!sync_bitmap) {
- error_setg(errp, "must provide a valid bitmap name for "
- "\"incremental\" sync mode");
+ if (sync_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;
}
if (bdrv_dirty_bitmap_create_successor(bs, sync_bitmap, errp) < 0) {
return NULL;
}
- } else if (sync_bitmap) {
- error_setg(errp,
- "a sync_bitmap was provided to backup_run, "
- "but received an incompatible sync_mode (%s)",
- MirrorSyncMode_str(sync_mode));
- return NULL;
}
len = bdrv_getlength(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,
}
/* The target must match the source in size, so no resize here either */
- job->target = blk_new(BLK_PERM_WRITE,
+ 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_mode == MIRROR_SYNC_MODE_INCREMENTAL ?
- sync_bitmap : NULL;
- job->compress = compress;
+ job->sync_bitmap = sync_bitmap;
+ job->bitmap_mode = bitmap_mode;
- /* 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);
- job->cluster_size = 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");
- goto error;
- } else if (ret < 0 && target->backing) {
- /* Not fatal; just trudge on ahead. */
- job->cluster_size = BACKUP_CLUSTER_SIZE_DEFAULT;
- } else {
- job->cluster_size = MAX(BACKUP_CLUSTER_SIZE_DEFAULT, bdi.cluster_size);
- }
- job->use_copy_range = true;
+ /*
+ * Set write flags:
+ * 1. Detect image-fleecing (and similar) schemes
+ * 2. Handle compression
+ */
+ job->write_flags =
+ (bdrv_chain_contains(target, bs) ? BDRV_REQ_SERIALISING : 0) |
+ (compress ? BDRV_REQ_WRITE_COMPRESSED : 0);
+
+ 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,
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);
}
projects / qemu.git / blobdiff