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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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52
block/block-copy.c
View file

@ -21,12 +21,14 @@
#include "qemu/units.h"
#include "qemu/coroutine.h"
#include "block/aio_task.h"
#include "qemu/error-report.h"
#define BLOCK_COPY_MAX_COPY_RANGE (16 * MiB)
#define BLOCK_COPY_MAX_BUFFER (1 * MiB)
#define BLOCK_COPY_MAX_MEM (128 * MiB)
#define BLOCK_COPY_MAX_WORKERS 64
#define BLOCK_COPY_SLICE_TIME 100000000ULL /* ns */
#define BLOCK_COPY_CLUSTER_SIZE_DEFAULT (1 << 16)
typedef enum {
COPY_READ_WRITE_CLUSTER,
@ -342,14 +344,57 @@ void block_copy_set_copy_opts(BlockCopyState *s, bool use_copy_range,
}
}
static int64_t block_copy_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",
BLOCK_COPY_CLUSTER_SIZE_DEFAULT);
return BLOCK_COPY_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 BLOCK_COPY_CLUSTER_SIZE_DEFAULT;
}
return MAX(BLOCK_COPY_CLUSTER_SIZE_DEFAULT, bdi.cluster_size);
}
BlockCopyState *block_copy_state_new(BdrvChild *source, BdrvChild *target,
int64_t cluster_size, bool use_copy_range,
bool use_copy_range,
bool compress, Error **errp)
{
BlockCopyState *s;
int64_t cluster_size;
BdrvDirtyBitmap *copy_bitmap;
bool is_fleecing;
cluster_size = block_copy_calculate_cluster_size(target->bs, errp);
if (cluster_size < 0) {
return NULL;
}
copy_bitmap = bdrv_create_dirty_bitmap(source->bs, cluster_size, NULL,
errp);
if (!copy_bitmap) {
@ -960,6 +1005,11 @@ BdrvDirtyBitmap *block_copy_dirty_bitmap(BlockCopyState *s)
return s->copy_bitmap;
}
int64_t block_copy_cluster_size(BlockCopyState *s)
{
return s->cluster_size;
}
void block_copy_set_skip_unallocated(BlockCopyState *s, bool skip)
{
qatomic_set(&s->skip_unallocated, skip);