diff options
author | Kevin Wolf <kwolf@redhat.com> | 2023-09-11 11:46:19 +0200 |
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committer | Kevin Wolf <kwolf@redhat.com> | 2023-09-20 17:46:01 +0200 |
commit | 32a8aba37eaae54d3a0a7ae5e93e3e157525660a (patch) | |
tree | c310d966906d71c635c89425f2e1f314dfafdba9 /block.c | |
parent | ede01e4635050a395eacd57b7d7fbea8ea208704 (diff) | |
download | qemu-32a8aba37eaae54d3a0a7ae5e93e3e157525660a.zip qemu-32a8aba37eaae54d3a0a7ae5e93e3e157525660a.tar.gz qemu-32a8aba37eaae54d3a0a7ae5e93e3e157525660a.tar.bz2 |
block: Mark bdrv_unref_child() GRAPH_WRLOCK
Instead of taking the writer lock internally, require callers to already
hold it when calling bdrv_unref_child(). These callers will typically
already hold the graph lock once the locking work is completed, which
means that they can't call functions that take it internally.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-21-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block.c')
-rw-r--r-- | block.c | 11 |
1 files changed, 7 insertions, 4 deletions
@@ -1701,7 +1701,9 @@ bdrv_open_driver(BlockDriverState *bs, BlockDriver *drv, const char *node_name, open_failed: bs->drv = NULL; if (bs->file != NULL) { + bdrv_graph_wrlock(NULL); bdrv_unref_child(bs, bs->file); + bdrv_graph_wrunlock(); assert(!bs->file); } g_free(bs->opaque); @@ -3331,8 +3333,9 @@ static void bdrv_set_inherits_from(BlockDriverState *bs, * @root that point to @root, where necessary. * @tran is allowed to be NULL. In this case no rollback is possible */ -static void bdrv_unset_inherits_from(BlockDriverState *root, BdrvChild *child, - Transaction *tran) +static void GRAPH_WRLOCK +bdrv_unset_inherits_from(BlockDriverState *root, BdrvChild *child, + Transaction *tran) { BdrvChild *c; @@ -3364,10 +3367,8 @@ void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child) return; } - bdrv_graph_wrlock(NULL); bdrv_unset_inherits_from(parent, child, NULL); bdrv_root_unref_child(child); - bdrv_graph_wrunlock(); } @@ -5164,9 +5165,11 @@ static void bdrv_close(BlockDriverState *bs) bs->drv = NULL; } + bdrv_graph_wrlock(NULL); QLIST_FOREACH_SAFE(child, &bs->children, next, next) { bdrv_unref_child(bs, child); } + bdrv_graph_wrunlock(); assert(!bs->backing); assert(!bs->file); |