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block/snapshot: drop indirection around bdrv_snapshot_fallback_ptr

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Now the indirection is not actually used, we can safely reduce it to
simple pointer. For consistency do a bit of refactoring to get rid of
_ptr suffixes that become meaningless.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220726201134.924743-15-vsementsov@yandex-team.ru>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Vladimir Sementsov-Ogievskiy 2022-07-26 23:11:33 +03:00 committed by Kevin Wolf
parent 5bb0474778
commit c5c2174146
1 changed files with 16 additions and 22 deletions
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38
block/snapshot.c
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@ -151,34 +151,29 @@ bool bdrv_snapshot_find_by_id_and_name(BlockDriverState *bs,
}
/**
* Return a pointer to the child BDS pointer to which we can fall
* Return a pointer to child of given BDS to which we can fall
* back if the given BDS does not support snapshots.
* Return NULL if there is no BDS to (safely) fall back to.
*
* We need to return an indirect pointer because bdrv_snapshot_goto()
* has to modify the BdrvChild pointer.
*/
static BdrvChild **bdrv_snapshot_fallback_ptr(BlockDriverState *bs)
static BdrvChild *bdrv_snapshot_fallback_child(BlockDriverState *bs)
{
BdrvChild **fallback;
BdrvChild *child = bdrv_primary_child(bs);
BdrvChild *fallback = bdrv_primary_child(bs);
BdrvChild *child;
/* We allow fallback only to primary child */
if (!child) {
if (!fallback) {
return NULL;
}
fallback = (child == bs->file ? &bs->file : &bs->backing);
assert(*fallback == child);
/*
* Check that there are no other children that would need to be
* snapshotted. If there are, it is not safe to fall back to
* *fallback.
* fallback.
*/
QLIST_FOREACH(child, &bs->children, next) {
if (child->role & (BDRV_CHILD_DATA | BDRV_CHILD_METADATA |
BDRV_CHILD_FILTERED) &&
child != *fallback)
child != fallback)
{
return NULL;
}
@ -189,8 +184,7 @@ static BdrvChild **bdrv_snapshot_fallback_ptr(BlockDriverState *bs)
static BlockDriverState *bdrv_snapshot_fallback(BlockDriverState *bs)
{
BdrvChild **child_ptr = bdrv_snapshot_fallback_ptr(bs);
return child_ptr ? (*child_ptr)->bs : NULL;
return child_bs(bdrv_snapshot_fallback_child(bs));
}
int bdrv_can_snapshot(BlockDriverState *bs)
@ -237,7 +231,7 @@ int bdrv_snapshot_goto(BlockDriverState *bs,
Error **errp)
{
BlockDriver *drv = bs->drv;
BdrvChild **fallback_ptr;
BdrvChild *fallback;
int ret, open_ret;
GLOBAL_STATE_CODE();
@ -260,13 +254,13 @@ int bdrv_snapshot_goto(BlockDriverState *bs,
return ret;
}
fallback_ptr = bdrv_snapshot_fallback_ptr(bs);
if (fallback_ptr) {
fallback = bdrv_snapshot_fallback_child(bs);
if (fallback) {
QDict *options;
QDict *file_options;
Error *local_err = NULL;
BlockDriverState *fallback_bs = (*fallback_ptr)->bs;
char *subqdict_prefix = g_strdup_printf("%s.", (*fallback_ptr)->name);
BlockDriverState *fallback_bs = fallback->bs;
char *subqdict_prefix = g_strdup_printf("%s.", fallback->name);
options = qdict_clone_shallow(bs->options);
@ -277,8 +271,8 @@ int bdrv_snapshot_goto(BlockDriverState *bs,
qobject_unref(file_options);
g_free(subqdict_prefix);
/* Force .bdrv_open() below to re-attach fallback_bs on *fallback_ptr */
qdict_put_str(options, (*fallback_ptr)->name,
/* Force .bdrv_open() below to re-attach fallback_bs on fallback */
qdict_put_str(options, fallback->name,
bdrv_get_node_name(fallback_bs));
/* Now close bs, apply the snapshot on fallback_bs, and re-open bs */
@ -287,7 +281,7 @@ int bdrv_snapshot_goto(BlockDriverState *bs,
}
/* .bdrv_open() will re-attach it */
bdrv_unref_child(bs, *fallback_ptr);
bdrv_unref_child(bs, fallback);
ret = bdrv_snapshot_goto(fallback_bs, snapshot_id, errp);
open_ret = drv->bdrv_open(bs, options, bs->open_flags, &local_err);