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author | Kevin Wolf <kwolf@redhat.com> | 2023-09-29 16:51:42 +0200 |
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committer | Kevin Wolf <kwolf@redhat.com> | 2023-10-12 16:31:33 +0200 |
commit | a32e781838e7231f2239bde0ac2f105dc7072abb (patch) | |
tree | 3a44059bd820f9bef374ff7e4fbcea5b64a8a637 /block | |
parent | 7859c45a4662284fde4d6b5548263197e8aa4f24 (diff) | |
download | qemu-a32e781838e7231f2239bde0ac2f105dc7072abb.zip qemu-a32e781838e7231f2239bde0ac2f105dc7072abb.tar.gz qemu-a32e781838e7231f2239bde0ac2f105dc7072abb.tar.bz2 |
block: Mark bdrv_snapshot_fallback() and callers GRAPH_RDLOCK
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_snapshot_fallback() need to hold a reader lock for the graph
because it accesses the children list of a node.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-8-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block')
-rw-r--r-- | block/snapshot.c | 35 |
1 files changed, 29 insertions, 6 deletions
diff --git a/block/snapshot.c b/block/snapshot.c index 633391e..5540655 100644 --- a/block/snapshot.c +++ b/block/snapshot.c @@ -155,11 +155,15 @@ bool bdrv_snapshot_find_by_id_and_name(BlockDriverState *bs, * back if the given BDS does not support snapshots. * Return NULL if there is no BDS to (safely) fall back to. */ -static BdrvChild *bdrv_snapshot_fallback_child(BlockDriverState *bs) +static BdrvChild * GRAPH_RDLOCK +bdrv_snapshot_fallback_child(BlockDriverState *bs) { BdrvChild *fallback = bdrv_primary_child(bs); BdrvChild *child; + GLOBAL_STATE_CODE(); + assert_bdrv_graph_readable(); + /* We allow fallback only to primary child */ if (!fallback) { return NULL; @@ -182,8 +186,10 @@ static BdrvChild *bdrv_snapshot_fallback_child(BlockDriverState *bs) return fallback; } -static BlockDriverState *bdrv_snapshot_fallback(BlockDriverState *bs) +static BlockDriverState * GRAPH_RDLOCK +bdrv_snapshot_fallback(BlockDriverState *bs) { + GLOBAL_STATE_CODE(); return child_bs(bdrv_snapshot_fallback_child(bs)); } @@ -254,7 +260,10 @@ int bdrv_snapshot_goto(BlockDriverState *bs, return ret; } + bdrv_graph_rdlock_main_loop(); fallback = bdrv_snapshot_fallback_child(bs); + bdrv_graph_rdunlock_main_loop(); + if (fallback) { QDict *options; QDict *file_options; @@ -374,10 +383,12 @@ int bdrv_snapshot_delete(BlockDriverState *bs, int bdrv_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_info) { + GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); + BlockDriver *drv = bs->drv; BlockDriverState *fallback_bs = bdrv_snapshot_fallback(bs); - GLOBAL_STATE_CODE(); if (!drv) { return -ENOMEDIUM; } @@ -498,6 +509,9 @@ bdrv_all_get_snapshot_devices(bool has_devices, strList *devices, static bool GRAPH_RDLOCK bdrv_all_snapshots_includes_bs(BlockDriverState *bs) { + GLOBAL_STATE_CODE(); + assert_bdrv_graph_readable(); + if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) { return false; } @@ -595,11 +609,15 @@ int bdrv_all_goto_snapshot(const char *name, { g_autoptr(GList) bdrvs = NULL; GList *iterbdrvs; + int ret; GLOBAL_STATE_CODE(); - GRAPH_RDLOCK_GUARD_MAINLOOP(); - if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0) { + bdrv_graph_rdlock_main_loop(); + ret = bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp); + bdrv_graph_rdunlock_main_loop(); + + if (ret < 0) { return -1; } @@ -608,9 +626,14 @@ int bdrv_all_goto_snapshot(const char *name, BlockDriverState *bs = iterbdrvs->data; AioContext *ctx = bdrv_get_aio_context(bs); int ret = 0; + bool all_snapshots_includes_bs; aio_context_acquire(ctx); - if (devices || bdrv_all_snapshots_includes_bs(bs)) { + bdrv_graph_rdlock_main_loop(); + all_snapshots_includes_bs = bdrv_all_snapshots_includes_bs(bs); + bdrv_graph_rdunlock_main_loop(); + + if (devices || all_snapshots_includes_bs) { ret = bdrv_snapshot_goto(bs, name, errp); } aio_context_release(ctx); |