From 32a8aba37eaae54d3a0a7ae5e93e3e157525660a Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Mon, 11 Sep 2023 11:46:19 +0200 Subject: [PATCH] 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 Reviewed-by: Emanuele Giuseppe Esposito Reviewed-by: Stefan Hajnoczi Message-ID: <20230911094620.45040-21-kwolf@redhat.com> Signed-off-by: Kevin Wolf --- block.c | 11 +++++++---- block/blklogwrites.c | 4 ++++ block/blkverify.c | 2 ++ block/qcow2.c | 4 +++- block/quorum.c | 6 ++++++ block/replication.c | 3 +++ block/snapshot.c | 2 ++ block/vmdk.c | 11 +++++++++++ include/block/block-global-state.h | 7 ++++++- tests/unit/test-bdrv-drain.c | 8 ++++++-- 10 files changed, 50 insertions(+), 8 deletions(-) diff --git a/block.c b/block.c index 9ea8333a28..e7f349b25c 100644 --- a/block.c +++ b/block.c @@ -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); diff --git a/block/blklogwrites.c b/block/blklogwrites.c index 3ea7141cb5..a0d70729bb 100644 --- a/block/blklogwrites.c +++ b/block/blklogwrites.c @@ -251,7 +251,9 @@ static int blk_log_writes_open(BlockDriverState *bs, QDict *options, int flags, ret = 0; fail_log: if (ret < 0) { + bdrv_graph_wrlock(NULL); bdrv_unref_child(bs, s->log_file); + bdrv_graph_wrunlock(); s->log_file = NULL; } fail: @@ -263,8 +265,10 @@ static void blk_log_writes_close(BlockDriverState *bs) { BDRVBlkLogWritesState *s = bs->opaque; + bdrv_graph_wrlock(NULL); bdrv_unref_child(bs, s->log_file); s->log_file = NULL; + bdrv_graph_wrunlock(); } static int64_t coroutine_fn GRAPH_RDLOCK diff --git a/block/blkverify.c b/block/blkverify.c index 7326461f30..dae9716a26 100644 --- a/block/blkverify.c +++ b/block/blkverify.c @@ -151,8 +151,10 @@ static void blkverify_close(BlockDriverState *bs) { BDRVBlkverifyState *s = bs->opaque; + bdrv_graph_wrlock(NULL); bdrv_unref_child(bs, s->test_file); s->test_file = NULL; + bdrv_graph_wrunlock(); } static int64_t coroutine_fn GRAPH_RDLOCK diff --git a/block/qcow2.c b/block/qcow2.c index b48cd9ce63..071004b302 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1880,7 +1880,7 @@ qcow2_do_open(BlockDriverState *bs, QDict *options, int flags, g_free(s->image_data_file); if (open_data_file && has_data_file(bs)) { bdrv_graph_co_rdunlock(); - bdrv_unref_child(bs, s->data_file); + bdrv_co_unref_child(bs, s->data_file); bdrv_graph_co_rdlock(); s->data_file = NULL; } @@ -2790,7 +2790,9 @@ static void qcow2_do_close(BlockDriverState *bs, bool close_data_file) g_free(s->image_backing_format); if (close_data_file && has_data_file(bs)) { + bdrv_graph_wrlock(NULL); bdrv_unref_child(bs, s->data_file); + bdrv_graph_wrunlock(); s->data_file = NULL; } diff --git a/block/quorum.c b/block/quorum.c index def0539fda..620a50ba2c 100644 --- a/block/quorum.c +++ b/block/quorum.c @@ -1037,12 +1037,14 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags, close_exit: /* cleanup on error */ + bdrv_graph_wrlock(NULL); for (i = 0; i < s->num_children; i++) { if (!opened[i]) { continue; } bdrv_unref_child(bs, s->children[i]); } + bdrv_graph_wrunlock(); g_free(s->children); g_free(opened); exit: @@ -1055,9 +1057,11 @@ static void quorum_close(BlockDriverState *bs) BDRVQuorumState *s = bs->opaque; int i; + bdrv_graph_wrlock(NULL); for (i = 0; i < s->num_children; i++) { bdrv_unref_child(bs, s->children[i]); } + bdrv_graph_wrunlock(); g_free(s->children); } @@ -1147,7 +1151,9 @@ static void quorum_del_child(BlockDriverState *bs, BdrvChild *child, memmove(&s->children[i], &s->children[i + 1], (s->num_children - i - 1) * sizeof(BdrvChild *)); s->children = g_renew(BdrvChild *, s->children, --s->num_children); + bdrv_graph_wrlock(NULL); bdrv_unref_child(bs, child); + bdrv_graph_wrunlock(); quorum_refresh_flags(bs); bdrv_drained_end(bs); diff --git a/block/replication.c b/block/replication.c index eec9819625..dd166d2d82 100644 --- a/block/replication.c +++ b/block/replication.c @@ -672,10 +672,13 @@ static void replication_done(void *opaque, int ret) if (ret == 0) { s->stage = BLOCK_REPLICATION_DONE; + bdrv_graph_wrlock(NULL); bdrv_unref_child(bs, s->secondary_disk); s->secondary_disk = NULL; bdrv_unref_child(bs, s->hidden_disk); s->hidden_disk = NULL; + bdrv_graph_wrunlock(); + s->error = 0; } else { s->stage = BLOCK_REPLICATION_FAILOVER_FAILED; diff --git a/block/snapshot.c b/block/snapshot.c index e22ac3eac6..b86b5b24ad 100644 --- a/block/snapshot.c +++ b/block/snapshot.c @@ -281,7 +281,9 @@ int bdrv_snapshot_goto(BlockDriverState *bs, } /* .bdrv_open() will re-attach it */ + bdrv_graph_wrlock(NULL); bdrv_unref_child(bs, fallback); + bdrv_graph_wrunlock(); ret = bdrv_snapshot_goto(fallback_bs, snapshot_id, errp); open_ret = drv->bdrv_open(bs, options, bs->open_flags, &local_err); diff --git a/block/vmdk.c b/block/vmdk.c index 84185b73a2..78baa04c0c 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -272,6 +272,7 @@ static void vmdk_free_extents(BlockDriverState *bs) BDRVVmdkState *s = bs->opaque; VmdkExtent *e; + bdrv_graph_wrlock(NULL); for (i = 0; i < s->num_extents; i++) { e = &s->extents[i]; g_free(e->l1_table); @@ -282,6 +283,8 @@ static void vmdk_free_extents(BlockDriverState *bs) bdrv_unref_child(bs, e->file); } } + bdrv_graph_wrunlock(); + g_free(s->extents); } @@ -1220,7 +1223,9 @@ static int vmdk_parse_extents(const char *desc, BlockDriverState *bs, ret = vmdk_add_extent(bs, extent_file, true, sectors, 0, 0, 0, 0, 0, &extent, errp); if (ret < 0) { + bdrv_graph_wrlock(NULL); bdrv_unref_child(bs, extent_file); + bdrv_graph_wrunlock(); goto out; } extent->flat_start_offset = flat_offset << 9; @@ -1235,20 +1240,26 @@ static int vmdk_parse_extents(const char *desc, BlockDriverState *bs, } g_free(buf); if (ret) { + bdrv_graph_wrlock(NULL); bdrv_unref_child(bs, extent_file); + bdrv_graph_wrunlock(); goto out; } extent = &s->extents[s->num_extents - 1]; } else if (!strcmp(type, "SESPARSE")) { ret = vmdk_open_se_sparse(bs, extent_file, bs->open_flags, errp); if (ret) { + bdrv_graph_wrlock(NULL); bdrv_unref_child(bs, extent_file); + bdrv_graph_wrunlock(); goto out; } extent = &s->extents[s->num_extents - 1]; } else { error_setg(errp, "Unsupported extent type '%s'", type); + bdrv_graph_wrlock(NULL); bdrv_unref_child(bs, extent_file); + bdrv_graph_wrunlock(); ret = -ENOTSUP; goto out; } diff --git a/include/block/block-global-state.h b/include/block/block-global-state.h index eb12a35439..0f6df8f1a2 100644 --- a/include/block/block-global-state.h +++ b/include/block/block-global-state.h @@ -225,7 +225,12 @@ void bdrv_ref(BlockDriverState *bs); void no_coroutine_fn bdrv_unref(BlockDriverState *bs); void coroutine_fn no_co_wrapper bdrv_co_unref(BlockDriverState *bs); void GRAPH_WRLOCK bdrv_schedule_unref(BlockDriverState *bs); -void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child); + +void GRAPH_WRLOCK +bdrv_unref_child(BlockDriverState *parent, BdrvChild *child); + +void coroutine_fn no_co_wrapper_bdrv_wrlock +bdrv_co_unref_child(BlockDriverState *parent, BdrvChild *child); BdrvChild * GRAPH_WRLOCK bdrv_attach_child(BlockDriverState *parent_bs, diff --git a/tests/unit/test-bdrv-drain.c b/tests/unit/test-bdrv-drain.c index 6d33249656..b040a73bb9 100644 --- a/tests/unit/test-bdrv-drain.c +++ b/tests/unit/test-bdrv-drain.c @@ -967,9 +967,12 @@ typedef struct BDRVTestTopState { static void bdrv_test_top_close(BlockDriverState *bs) { BdrvChild *c, *next_c; + + bdrv_graph_wrlock(NULL); QLIST_FOREACH_SAFE(c, &bs->children, next, next_c) { bdrv_unref_child(bs, c); } + bdrv_graph_wrunlock(); } static int coroutine_fn GRAPH_RDLOCK @@ -1024,7 +1027,7 @@ static void coroutine_fn test_co_delete_by_drain(void *opaque) } else { BdrvChild *c, *next_c; QLIST_FOREACH_SAFE(c, &bs->children, next, next_c) { - bdrv_unref_child(bs, c); + bdrv_co_unref_child(bs, c); } } @@ -1162,10 +1165,11 @@ static void detach_indirect_bh(void *opaque) struct detach_by_parent_data *data = opaque; bdrv_dec_in_flight(data->child_b->bs); + + bdrv_graph_wrlock(NULL); bdrv_unref_child(data->parent_b, data->child_b); bdrv_ref(data->c); - bdrv_graph_wrlock(NULL); data->child_c = bdrv_attach_child(data->parent_b, data->c, "PB-C", &child_of_bds, BDRV_CHILD_DATA, &error_abort);