motorhead/qemu
1
0
Fork 0
mirror of https://github.com/Motorhead1991/qemu.git synced 2025-08-07 01:33:56 -06:00
Code Issues Projects Releases Packages Wiki Activity Actions

block: Mark bdrv_(un)freeze_backing_chain() and callers GRAPH_RDLOCK

Browse source 
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_(un)freeze_backing_chain() need to hold a reader lock for the
graph because it calls bdrv_filter_or_cow_child(), which accesses
bs->file/backing.

Use the opportunity to make bdrv_is_backing_chain_frozen() static, it
has no external callers.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-10-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Kevin Wolf 2023-10-27 17:53:18 +02:00
parent ad74751fc0
commit 9275fc72bd
7 changed files with 46 additions and 17 deletions
Download patch file Download diff file Expand all files Collapse all files

19
block/copy-on-read.c
View file

@ -35,8 +35,8 @@ typedef struct BDRVStateCOR {
} BDRVStateCOR;
static int cor_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
static int GRAPH_UNLOCKED
cor_open(BlockDriverState *bs, QDict *options, int flags, Error **errp)
{
BlockDriverState *bottom_bs = NULL;
BDRVStateCOR *state = bs->opaque;
@ -44,6 +44,8 @@ static int cor_open(BlockDriverState *bs, QDict *options, int flags,
const char *bottom_node = qdict_get_try_str(options, "bottom");
int ret;
GLOBAL_STATE_CODE();
ret = bdrv_open_file_child(NULL, options, "file", bs, errp);
if (ret < 0) {
return ret;
@ -59,6 +61,8 @@ static int cor_open(BlockDriverState *bs, QDict *options, int flags,
bs->file->bs->supported_zero_flags);
if (bottom_node) {
GRAPH_RDLOCK_GUARD_MAINLOOP();
bottom_bs = bdrv_find_node(bottom_node);
if (!bottom_bs) {
error_setg(errp, "Bottom node '%s' not found", bottom_node);
@ -227,13 +231,17 @@ cor_co_lock_medium(BlockDriverState *bs, bool locked)
}
static void cor_close(BlockDriverState *bs)
static void GRAPH_UNLOCKED cor_close(BlockDriverState *bs)
{
BDRVStateCOR *s = bs->opaque;
GLOBAL_STATE_CODE();
if (s->chain_frozen) {
bdrv_graph_rdlock_main_loop();
s->chain_frozen = false;
bdrv_unfreeze_backing_chain(bs, s->bottom_bs);
bdrv_graph_rdunlock_main_loop();
}
bdrv_unref(s->bottom_bs);
@ -263,12 +271,15 @@ static BlockDriver bdrv_copy_on_read = {
};
void bdrv_cor_filter_drop(BlockDriverState *cor_filter_bs)
void no_coroutine_fn bdrv_cor_filter_drop(BlockDriverState *cor_filter_bs)
{
BDRVStateCOR *s = cor_filter_bs->opaque;
GLOBAL_STATE_CODE();
/* unfreeze, as otherwise bdrv_replace_node() will fail */
if (s->chain_frozen) {
GRAPH_RDLOCK_GUARD_MAINLOOP();
s->chain_frozen = false;
bdrv_unfreeze_backing_chain(cor_filter_bs, s->bottom_bs);
}