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block/backup-top: fix flags handling

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backup-top "supports" write-unchanged, by skipping CBW operation in
backup_top_co_pwritev. But it forgets to do the same in
backup_top_co_pwrite_zeroes, as well as declare support for
BDRV_REQ_WRITE_UNCHANGED.

Fix this, and, while being here, declare also support for flags
supported by source child.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200207161231.32707-1-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Vladimir Sementsov-Ogievskiy 2020-02-07 19:12:31 +03:00 committed by Max Reitz
parent 087ab8e775
commit 4bc267a7c7
1 changed files with 20 additions and 11 deletions
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31
block/backup-top.c
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@ -48,11 +48,17 @@ static coroutine_fn int backup_top_co_preadv(
}
static coroutine_fn int backup_top_cbw(BlockDriverState *bs, uint64_t offset,
uint64_t bytes)
uint64_t bytes, BdrvRequestFlags flags)
{
BDRVBackupTopState *s = bs->opaque;
uint64_t end = QEMU_ALIGN_UP(offset + bytes, s->bcs->cluster_size);
uint64_t off = QEMU_ALIGN_DOWN(offset, s->bcs->cluster_size);
uint64_t off, end;
if (flags & BDRV_REQ_WRITE_UNCHANGED) {
return 0;
}
off = QEMU_ALIGN_DOWN(offset, s->bcs->cluster_size);
end = QEMU_ALIGN_UP(offset + bytes, s->bcs->cluster_size);
return block_copy(s->bcs, off, end - off, NULL);
}
@ -60,7 +66,7 @@ static coroutine_fn int backup_top_cbw(BlockDriverState *bs, uint64_t offset,
static int coroutine_fn backup_top_co_pdiscard(BlockDriverState *bs,
int64_t offset, int bytes)
{
int ret = backup_top_cbw(bs, offset, bytes);
int ret = backup_top_cbw(bs, offset, bytes, 0);
if (ret < 0) {
return ret;
}
@ -71,7 +77,7 @@ static int coroutine_fn backup_top_co_pdiscard(BlockDriverState *bs,
static int coroutine_fn backup_top_co_pwrite_zeroes(BlockDriverState *bs,
int64_t offset, int bytes, BdrvRequestFlags flags)
{
int ret = backup_top_cbw(bs, offset, bytes);
int ret = backup_top_cbw(bs, offset, bytes, flags);
if (ret < 0) {
return ret;
}
@ -84,11 +90,9 @@ static coroutine_fn int backup_top_co_pwritev(BlockDriverState *bs,
uint64_t bytes,
QEMUIOVector *qiov, int flags)
{
if (!(flags & BDRV_REQ_WRITE_UNCHANGED)) {
int ret = backup_top_cbw(bs, offset, bytes);
if (ret < 0) {
return ret;
}
int ret = backup_top_cbw(bs, offset, bytes, flags);
if (ret < 0) {
return ret;
}
return bdrv_co_pwritev(bs->backing, offset, bytes, qiov, flags);
@ -196,8 +200,13 @@ BlockDriverState *bdrv_backup_top_append(BlockDriverState *source,
return NULL;
}
top->total_sectors = source->total_sectors;
state = top->opaque;
top->total_sectors = source->total_sectors;
top->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED |
(BDRV_REQ_FUA & source->supported_write_flags);
top->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED |
((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK) &
source->supported_zero_flags);
bdrv_ref(target);
state->target = bdrv_attach_child(top, target, "target", &child_file, errp);