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block: Mark bdrv_root_unref_child() GRAPH_WRLOCK

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Instead of taking the writer lock internally, require callers to already
hold it when calling bdrv_root_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: <20230911094620.45040-20-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Kevin Wolf 2023-09-11 11:46:18 +02:00
parent 7f831d29e3
commit ede01e4635
4 changed files with 9 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
block.c
View File

@ -3268,7 +3268,6 @@ void bdrv_root_unref_child(BdrvChild *child)
BlockDriverState *child_bs = child->bs; BlockDriverState *child_bs = child->bs;
GLOBAL_STATE_CODE(); GLOBAL_STATE_CODE();
bdrv_graph_wrlock(NULL);
bdrv_replace_child_noperm(child, NULL); bdrv_replace_child_noperm(child, NULL);
bdrv_child_free(child); bdrv_child_free(child);
@ -3288,8 +3287,7 @@ void bdrv_root_unref_child(BdrvChild *child)
NULL); NULL);
} }
bdrv_graph_wrunlock(); bdrv_schedule_unref(child_bs);
bdrv_unref(child_bs);
} }
typedef struct BdrvSetInheritsFrom { typedef struct BdrvSetInheritsFrom {
@ -3366,8 +3364,10 @@ void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child)
return; return;
} }
bdrv_graph_wrlock(NULL);
bdrv_unset_inherits_from(parent, child, NULL); bdrv_unset_inherits_from(parent, child, NULL);
bdrv_root_unref_child(child); bdrv_root_unref_child(child);
bdrv_graph_wrunlock();
} }

3
block/block-backend.c
View File

@ -915,7 +915,10 @@ void blk_remove_bs(BlockBackend *blk)
blk_drain(blk); blk_drain(blk);
root = blk->root; root = blk->root;
blk->root = NULL; blk->root = NULL;
bdrv_graph_wrlock(NULL);
bdrv_root_unref_child(root); bdrv_root_unref_child(root);
bdrv_graph_wrunlock();
} }
/* /*

2
blockjob.c
View File

@ -198,6 +198,7 @@ void block_job_remove_all_bdrv(BlockJob *job)
* one to make sure that such a concurrent access does not attempt * one to make sure that such a concurrent access does not attempt
* to process an already freed BdrvChild. * to process an already freed BdrvChild.
*/ */
bdrv_graph_wrlock(NULL);
while (job->nodes) { while (job->nodes) {
GSList *l = job->nodes; GSList *l = job->nodes;
BdrvChild *c = l->data; BdrvChild *c = l->data;
@ -209,6 +210,7 @@ void block_job_remove_all_bdrv(BlockJob *job)
g_slist_free_1(l); g_slist_free_1(l);
} }
bdrv_graph_wrunlock();
} }
bool block_job_has_bdrv(BlockJob *job, BlockDriverState *bs) bool block_job_has_bdrv(BlockJob *job, BlockDriverState *bs)

2
include/block/block_int-global-state.h
View File

@ -202,7 +202,7 @@ BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
BdrvChildRole child_role, BdrvChildRole child_role,
uint64_t perm, uint64_t shared_perm, uint64_t perm, uint64_t shared_perm,
void *opaque, Error **errp); void *opaque, Error **errp);
void bdrv_root_unref_child(BdrvChild *child); void GRAPH_WRLOCK bdrv_root_unref_child(BdrvChild *child);
void GRAPH_RDLOCK bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm, void GRAPH_RDLOCK bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm,
uint64_t *shared_perm); uint64_t *shared_perm);