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block/backup: move cluster size calculation to block-copy

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The main consumer of cluster-size is block-copy. Let's calculate it
here instead of passing through backup-top.

We are going to publish copy-before-write filter soon, so it will be
created through options. But we don't want for now to make explicit
option for cluster-size, let's continue to calculate it automatically.
So, now is the time to get rid of cluster_size argument for
bdrv_cbw_append().

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210824083856.17408-10-vsementsov@virtuozzo.com>
[hreitz: Add qemu/error-report.h include to block/block-copy.c]
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
This commit is contained in:
Vladimir Sementsov-Ogievskiy
2021-08-24 11:38:31 +03:00
committed by Hanna Reitz
parent 2a6511dfeb
commit b518e9e9ef
5 changed files with 67 additions and 63 deletions
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block/backup.c
+9 -53
View File
@@ -29,8 +29,6 @@
#include "block/copy-before-write.h"
#define BACKUP_CLUSTER_SIZE_DEFAULT (1 << 16)
typedef struct BackupBlockJob {
BlockJob common;
BlockDriverState *cbw;
@@ -354,43 +352,6 @@ static const BlockJobDriver backup_job_driver = {
.set_speed = backup_set_speed,
};
static int64_t backup_calculate_cluster_size(BlockDriverState *target,
Error **errp)
{
int ret;
BlockDriverInfo bdi;
bool target_does_cow = bdrv_backing_chain_next(target);
/*
* 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_does_cow) {
/* 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_does_cow) {
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_does_cow) {
/* 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,
@@ -448,11 +409,6 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
return NULL;
}
cluster_size = backup_calculate_cluster_size(target, errp);
if (cluster_size < 0) {
goto error;
}
if (perf->max_workers < 1) {
error_setg(errp, "max-workers must be greater than zero");
return NULL;
@@ -464,13 +420,6 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
return NULL;
}
if (perf->max_chunk && perf->max_chunk < cluster_size) {
error_setg(errp, "Required max-chunk (%" PRIi64 ") is less than backup "
"cluster size (%" PRIi64 ")", perf->max_chunk, cluster_size);
return NULL;
}
if (sync_bitmap) {
/* If we need to write to this bitmap, check that we can: */
if (bitmap_mode != BITMAP_SYNC_MODE_NEVER &&
@@ -503,12 +452,19 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
goto error;
}
cbw = bdrv_cbw_append(bs, target, filter_node_name,
cluster_size, false, &bcs, errp);
cbw = bdrv_cbw_append(bs, target, filter_node_name, false, &bcs, errp);
if (!cbw) {
goto error;
}
cluster_size = block_copy_cluster_size(bcs);
if (perf->max_chunk && perf->max_chunk < cluster_size) {
error_setg(errp, "Required max-chunk (%" PRIi64 ") is less than backup "
"cluster size (%" PRIi64 ")", perf->max_chunk, cluster_size);
goto error;
}
/* job->len is fixed, so we can't allow resize */
job = block_job_create(job_id, &backup_job_driver, txn, cbw,
0, BLK_PERM_ALL,