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block/copy-before-write: introduce cbw_init() 

Move part of bdrv_cbw_append() to new function cbw_open(). It's an
intermediate step for adding normal .bdrv_open() handler to the
filter. With this commit no logic is changed, but we have a function
which will be turned into .bdrv_open() handler in future commit.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210824083856.17408-15-vsementsov@virtuozzo.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
This commit is contained in:
Vladimir Sementsov-Ogievskiy 2021-08-24 11:38:36 +03:00 committed by Hanna Reitz
parent 7ddbce2dec
commit 1f0cacb967
1 changed files with 41 additions and 28 deletions
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69
block/copy-before-write.c
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@ -144,6 +144,45 @@ static void cbw_child_perm(BlockDriverState *bs, BdrvChild *c,
} }
} }
static int cbw_init(BlockDriverState *top, BlockDriverState *source,
BlockDriverState *target, bool compress, Error **errp)
{
BDRVCopyBeforeWriteState *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_of_bds,
BDRV_CHILD_DATA, errp);
if (!state->target) {
error_prepend(errp, "Cannot attach target child: ");
return -EINVAL;
}
bdrv_ref(source);
top->file = bdrv_attach_child(top, source, "file", &child_of_bds,
BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY,
errp);
if (!top->file) {
error_prepend(errp, "Cannot attach file child: ");
return -EINVAL;
}
state->bcs = block_copy_state_new(top->file, state->target, false, compress,
errp);
if (!state->bcs) {
error_prepend(errp, "Cannot create block-copy-state: ");
return -EINVAL;
}
return 0;
}
BlockDriver bdrv_cbw_filter = { BlockDriver bdrv_cbw_filter = {
.format_name = "copy-before-write", .format_name = "copy-before-write",
.instance_size = sizeof(BDRVCopyBeforeWriteState), .instance_size = sizeof(BDRVCopyBeforeWriteState),
@ -181,36 +220,10 @@ BlockDriverState *bdrv_cbw_append(BlockDriverState *source,
error_prepend(errp, "Cannot open driver: "); error_prepend(errp, "Cannot open driver: ");
return NULL; return NULL;
} }
state = top->opaque; 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); ret = cbw_init(top, source, target, compress, errp);
state->target = bdrv_attach_child(top, target, "target", &child_of_bds, if (ret < 0) {
BDRV_CHILD_DATA, errp);
if (!state->target) {
error_prepend(errp, "Cannot attach target child: ");
goto fail;
}
bdrv_ref(source);
top->file = bdrv_attach_child(top, source, "file", &child_of_bds,
BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY,
errp);
if (!top->file) {
error_prepend(errp, "Cannot attach file child: ");
goto fail;
}
state->bcs = block_copy_state_new(top->file, state->target, false, compress,
errp);
if (!state->bcs) {
error_prepend(errp, "Cannot create block-copy-state: ");
goto fail; goto fail;
} }