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block/copy-on-read: use bdrv_drop_filter() and drop s->active

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Now, after huge update of block graph permission update algorithm, we
don't need this workaround with active state of the filter. Drop it and
use new smart bdrv_drop_filter() function.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210506194143.394141-1-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Vladimir Sementsov-Ogievskiy 2021-05-06 22:41:43 +03:00 committed by Max Reitz
parent d65173f924
commit bcc8584c83
1 changed files with 1 additions and 32 deletions
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33
block/copy-on-read.c
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@ -29,7 +29,6 @@
typedef struct BDRVStateCOR {
bool active;
BlockDriverState *bottom_bs;
bool chain_frozen;
} BDRVStateCOR;
@ -89,7 +88,6 @@ static int cor_open(BlockDriverState *bs, QDict *options, int flags,
*/
bdrv_ref(bottom_bs);
}
state->active = true;
state->bottom_bs = bottom_bs;
/*
@ -112,17 +110,6 @@ static void cor_child_perm(BlockDriverState *bs, BdrvChild *c,
uint64_t perm, uint64_t shared,
uint64_t *nperm, uint64_t *nshared)
{
BDRVStateCOR *s = bs->opaque;
if (!s->active) {
/*
* While the filter is being removed
*/
*nperm = 0;
*nshared = BLK_PERM_ALL;
return;
}
*nperm = perm & PERM_PASSTHROUGH;
*nshared = (shared & PERM_PASSTHROUGH) | PERM_UNCHANGED;
@ -280,32 +267,14 @@ static BlockDriver bdrv_copy_on_read = {
void bdrv_cor_filter_drop(BlockDriverState *cor_filter_bs)
{
BdrvChild *child;
BlockDriverState *bs;
BDRVStateCOR *s = cor_filter_bs->opaque;
child = bdrv_filter_child(cor_filter_bs);
if (!child) {
return;
}
bs = child->bs;
/* Retain the BDS until we complete the graph change. */
bdrv_ref(bs);
/* Hold a guest back from writing while permissions are being reset. */
bdrv_drained_begin(bs);
/* Drop permissions before the graph change. */
s->active = false;
/* unfreeze, as otherwise bdrv_replace_node() will fail */
if (s->chain_frozen) {
s->chain_frozen = false;
bdrv_unfreeze_backing_chain(cor_filter_bs, s->bottom_bs);
}
bdrv_child_refresh_perms(cor_filter_bs, child, &error_abort);
bdrv_replace_node(cor_filter_bs, bs, &error_abort);
bdrv_drained_end(bs);
bdrv_unref(bs);
bdrv_drop_filter(cor_filter_bs, &error_abort);
bdrv_unref(cor_filter_bs);
}