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;
- bool serialize_target_writes;
+ BdrvRequestFlags write_flags;
+ bool initializing_bitmap;
} BackupBlockJob;
static const BlockJobDriver backup_job_driver;
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));
- hbitmap_reset(job->copy_bitmap, 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);
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));
- }
+ 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);
+ bdrv_set_dirty_bitmap(job->copy_bitmap, start, job->cluster_size);
return 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(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,
- read_flags, write_flags);
+ 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);
while (start < end) {
int64_t dirty_end;
- if (!hbitmap_get(job->copy_bitmap, start)) {
+ 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 = hbitmap_next_zero(job->copy_bitmap, start, (end - start));
+ 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) {
{
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);
- assert(s->target);
- blk_unref(s->target);
- s->target = NULL;
+ BlockDriverState *bs = blk_bs(s->common.blk);
if (s->copy_bitmap) {
- hbitmap_free(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)
return;
}
- hbitmap_set(backup_job->copy_bitmap, 0, backup_job->len);
+ bdrv_set_dirty_bitmap(backup_job->copy_bitmap, 0, backup_job->len);
}
static void backup_drain(BlockJob *job)
return false;
}
-static bool bdrv_is_unallocated_range(BlockDriverState *bs,
- int64_t offset, int64_t bytes)
-{
- int64_t end = offset + bytes;
-
- while (offset < end && !bdrv_is_allocated(bs, offset, bytes, &bytes)) {
- if (bytes == 0) {
- return true;
- }
- offset += bytes;
- bytes = end - offset;
- }
-
- return offset >= end;
-}
-
static int coroutine_fn backup_loop(BackupBlockJob *job)
{
- int ret;
bool error_is_read;
int64_t offset;
- HBitmapIter hbi;
- BlockDriverState *bs = blk_bs(job->common.blk);
-
- hbitmap_iter_init(&hbi, job->copy_bitmap, 0);
- while ((offset = hbitmap_iter_next(&hbi)) != -1) {
- if (job->sync_mode == MIRROR_SYNC_MODE_TOP &&
- bdrv_is_unallocated_range(bs, offset, job->cluster_size))
- {
- hbitmap_reset(job->copy_bitmap, offset, job->cluster_size);
- continue;
- }
+ 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)) {
- return 0;
+ 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)
{
- 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)
{
- uint64_t offset = 0;
- uint64_t bytes = job->len;
-
- while (bdrv_dirty_bitmap_next_dirty_area(job->sync_bitmap,
- &offset, &bytes))
- {
- hbitmap_set(job->copy_bitmap, offset, bytes);
-
- offset += bytes;
- if (offset >= job->len) {
- 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;
}
- bytes = job->len - offset;
+ 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));
+ 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)
QLIST_INIT(&s->inflight_reqs);
qemu_co_rwlock_init(&s->flush_rwlock);
- job_progress_set_remaining(job, s->len);
-
- if (s->sync_mode == MIRROR_SYNC_MODE_INCREMENTAL) {
- backup_incremental_init_copy_bitmap(s);
- } else {
- hbitmap_set(s->copy_bitmap, 0, s->len);
- }
+ 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. */
ret = backup_loop(s);
}
+ out:
notifier_with_return_remove(&s->before_write);
/* wait until pending backup_do_cow() calls have completed */
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,
BackupBlockJob *job = NULL;
int ret;
int64_t cluster_size;
- HBitmap *copy_bitmap = NULL;
+ 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;
}
- copy_bitmap = hbitmap_alloc(len, ctz32(cluster_size));
+ 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,
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;
+
+ /*
+ * 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);
- /* 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;
error:
if (copy_bitmap) {
assert(!job || !job->copy_bitmap);
- hbitmap_free(copy_bitmap);
+ bdrv_release_dirty_bitmap(bs, copy_bitmap);
}
if (sync_bitmap) {
bdrv_reclaim_dirty_bitmap(bs, sync_bitmap, NULL);
projects / qemu.git / blobdiff