From 2b3912f1350971fbc2c04d986a1d0c60ae757c78 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Fri, 29 Sep 2023 16:51:39 +0200 Subject: [PATCH] block: Mark bdrv_first_blk() and bdrv_is_root_node() GRAPH_RDLOCK This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_first_blk() and bdrv_is_root_node() need to hold a reader lock for the graph. These functions are the only functions in block-backend.c that access the parent list of a node. Signed-off-by: Kevin Wolf Message-ID: <20230929145157.45443-5-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block.c | 1 + block/block-backend.c | 6 +++++- block/export/export.c | 4 ++++ block/io.c | 1 + block/monitor/block-hmp-cmds.c | 2 ++ block/qapi-sysemu.c | 2 ++ block/replication.c | 10 ++++++++-- block/snapshot.c | 15 +++++++++++---- blockdev.c | 5 +++++ include/block/block-global-state.h | 9 +++++---- include/sysemu/block-backend-global-state.h | 4 ++-- migration/block.c | 2 ++ migration/migration-hmp-cmds.c | 2 ++ tests/unit/test-block-iothread.c | 3 +++ 14 files changed, 53 insertions(+), 13 deletions(-) diff --git a/block.c b/block.c index b62f6f3841..701f77fe2f 100644 --- a/block.c +++ b/block.c @@ -6961,6 +6961,7 @@ void bdrv_activate_all(Error **errp) BdrvNextIterator it; GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { AioContext *aio_context = bdrv_get_aio_context(bs); diff --git a/block/block-backend.c b/block/block-backend.c index efe2e7cbf8..39b5f90a11 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -780,11 +780,12 @@ BlockDriverState *blk_bs(BlockBackend *blk) return blk->root ? blk->root->bs : NULL; } -static BlockBackend *bdrv_first_blk(BlockDriverState *bs) +static BlockBackend * GRAPH_RDLOCK bdrv_first_blk(BlockDriverState *bs) { BdrvChild *child; GLOBAL_STATE_CODE(); + assert_bdrv_graph_readable(); QLIST_FOREACH(child, &bs->parents, next_parent) { if (child->klass == &child_root) { @@ -812,6 +813,8 @@ bool bdrv_is_root_node(BlockDriverState *bs) BdrvChild *c; GLOBAL_STATE_CODE(); + assert_bdrv_graph_readable(); + QLIST_FOREACH(c, &bs->parents, next_parent) { if (c->klass != &child_root) { return false; @@ -2259,6 +2262,7 @@ void blk_activate(BlockBackend *blk, Error **errp) if (qemu_in_coroutine()) { bdrv_co_activate(bs, errp); } else { + GRAPH_RDLOCK_GUARD_MAINLOOP(); bdrv_activate(bs, errp); } } diff --git a/block/export/export.c b/block/export/export.c index 10316b43c5..a8f274e526 100644 --- a/block/export/export.c +++ b/block/export/export.c @@ -83,6 +83,8 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp) uint64_t perm; int ret; + GLOBAL_STATE_CODE(); + if (!id_wellformed(export->id)) { error_setg(errp, "Invalid block export id"); return NULL; @@ -145,7 +147,9 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp) * access since the export could be available before migration handover. * ctx was acquired in the caller. */ + bdrv_graph_rdlock_main_loop(); bdrv_activate(bs, NULL); + bdrv_graph_rdunlock_main_loop(); perm = BLK_PERM_CONSISTENT_READ; if (export->writable) { diff --git a/block/io.c b/block/io.c index 9e170929a7..5821a4d1f5 100644 --- a/block/io.c +++ b/block/io.c @@ -2330,6 +2330,7 @@ int bdrv_flush_all(void) int result = 0; GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); /* * bdrv queue is managed by record/replay, diff --git a/block/monitor/block-hmp-cmds.c b/block/monitor/block-hmp-cmds.c index ca2599de44..6b7d7dd072 100644 --- a/block/monitor/block-hmp-cmds.c +++ b/block/monitor/block-hmp-cmds.c @@ -896,6 +896,8 @@ void hmp_info_snapshots(Monitor *mon, const QDict *qdict) SnapshotEntry *snapshot_entry; Error *err = NULL; + GRAPH_RDLOCK_GUARD_MAINLOOP(); + bs = bdrv_all_find_vmstate_bs(NULL, false, NULL, &err); if (!bs) { error_report_err(err); diff --git a/block/qapi-sysemu.c b/block/qapi-sysemu.c index ef07151892..e885a64c32 100644 --- a/block/qapi-sysemu.c +++ b/block/qapi-sysemu.c @@ -279,6 +279,8 @@ static void blockdev_insert_medium(const char *device, const char *id, BlockBackend *blk; BlockDriverState *bs; + GRAPH_RDLOCK_GUARD_MAINLOOP(); + blk = qmp_get_blk(device, id, errp); if (!blk) { return; diff --git a/block/replication.c b/block/replication.c index 4ad3dd5115..107445d0ce 100644 --- a/block/replication.c +++ b/block/replication.c @@ -458,6 +458,8 @@ static void replication_start(ReplicationState *rs, ReplicationMode mode, Error *local_err = NULL; BackupPerf perf = { .use_copy_range = true, .max_workers = 1 }; + GLOBAL_STATE_CODE(); + aio_context = bdrv_get_aio_context(bs); aio_context_acquire(aio_context); s = bs->opaque; @@ -504,12 +506,15 @@ static void replication_start(ReplicationState *rs, ReplicationMode mode, return; } + bdrv_graph_rdlock_main_loop(); secondary_disk = hidden_disk->bs->backing; if (!secondary_disk->bs || !bdrv_has_blk(secondary_disk->bs)) { error_setg(errp, "The secondary disk doesn't have block backend"); + bdrv_graph_rdunlock_main_loop(); aio_context_release(aio_context); return; } + bdrv_graph_rdunlock_main_loop(); /* verify the length */ active_length = bdrv_getlength(active_disk->bs); @@ -566,8 +571,6 @@ static void replication_start(ReplicationState *rs, ReplicationMode mode, return; } - bdrv_graph_wrunlock(); - /* start backup job now */ error_setg(&s->blocker, "Block device is in use by internal backup job"); @@ -576,6 +579,7 @@ static void replication_start(ReplicationState *rs, ReplicationMode mode, if (!top_bs || !bdrv_is_root_node(top_bs) || !check_top_bs(top_bs, bs)) { error_setg(errp, "No top_bs or it is invalid"); + bdrv_graph_wrunlock(); reopen_backing_file(bs, false, NULL); aio_context_release(aio_context); return; @@ -583,6 +587,8 @@ static void replication_start(ReplicationState *rs, ReplicationMode mode, bdrv_op_block_all(top_bs, s->blocker); bdrv_op_unblock(top_bs, BLOCK_OP_TYPE_DATAPLANE, s->blocker); + bdrv_graph_wrunlock(); + s->backup_job = backup_job_create( NULL, s->secondary_disk->bs, s->hidden_disk->bs, 0, MIRROR_SYNC_MODE_NONE, NULL, 0, false, NULL, diff --git a/block/snapshot.c b/block/snapshot.c index b86b5b24ad..633391e8a9 100644 --- a/block/snapshot.c +++ b/block/snapshot.c @@ -462,9 +462,9 @@ int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState *bs, } -static int bdrv_all_get_snapshot_devices(bool has_devices, strList *devices, - GList **all_bdrvs, - Error **errp) +static int GRAPH_RDLOCK +bdrv_all_get_snapshot_devices(bool has_devices, strList *devices, + GList **all_bdrvs, Error **errp) { g_autoptr(GList) bdrvs = NULL; @@ -496,7 +496,7 @@ static int bdrv_all_get_snapshot_devices(bool has_devices, strList *devices, } -static bool bdrv_all_snapshots_includes_bs(BlockDriverState *bs) +static bool GRAPH_RDLOCK bdrv_all_snapshots_includes_bs(BlockDriverState *bs) { if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) { return false; @@ -518,6 +518,7 @@ bool bdrv_all_can_snapshot(bool has_devices, strList *devices, GList *iterbdrvs; GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0) { return false; @@ -554,6 +555,7 @@ int bdrv_all_delete_snapshot(const char *name, GList *iterbdrvs; GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0) { return -1; @@ -595,6 +597,7 @@ int bdrv_all_goto_snapshot(const char *name, GList *iterbdrvs; GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0) { return -1; @@ -631,6 +634,7 @@ int bdrv_all_has_snapshot(const char *name, GList *iterbdrvs; GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0) { return -1; @@ -673,7 +677,9 @@ int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn, { g_autoptr(GList) bdrvs = NULL; GList *iterbdrvs; + GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0) { return -1; @@ -715,6 +721,7 @@ BlockDriverState *bdrv_all_find_vmstate_bs(const char *vmstate_bs, GList *iterbdrvs; GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); if (bdrv_all_get_snapshot_devices(has_devices, devices, &bdrvs, errp) < 0) { return NULL; diff --git a/blockdev.c b/blockdev.c index 325b7a3bef..b6b7c44288 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1041,6 +1041,8 @@ static BlockDriverState *qmp_get_root_bs(const char *name, Error **errp) BlockDriverState *bs; AioContext *aio_context; + GRAPH_RDLOCK_GUARD_MAINLOOP(); + bs = bdrv_lookup_bs(name, name, errp); if (bs == NULL) { return NULL; @@ -3509,6 +3511,7 @@ void qmp_blockdev_del(const char *node_name, Error **errp) BlockDriverState *bs; GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); bs = bdrv_find_node(node_name); if (!bs) { @@ -3636,6 +3639,8 @@ void qmp_x_blockdev_set_iothread(const char *node_name, StrOrNull *iothread, AioContext *new_context; BlockDriverState *bs; + GRAPH_RDLOCK_GUARD_MAINLOOP(); + bs = bdrv_find_node(node_name); if (!bs) { error_setg(errp, "Failed to find node with node-name='%s'", node_name); diff --git a/include/block/block-global-state.h b/include/block/block-global-state.h index 6061220a6c..505a0d0c11 100644 --- a/include/block/block-global-state.h +++ b/include/block/block-global-state.h @@ -170,9 +170,10 @@ BlockDriverState * GRAPH_RDLOCK check_to_replace_node(BlockDriverState *parent_bs, const char *node_name, Error **errp); -int no_coroutine_fn bdrv_activate(BlockDriverState *bs, Error **errp); +int no_coroutine_fn GRAPH_RDLOCK +bdrv_activate(BlockDriverState *bs, Error **errp); -int coroutine_fn no_co_wrapper +int coroutine_fn no_co_wrapper_bdrv_rdlock bdrv_co_activate(BlockDriverState *bs, Error **errp); void bdrv_activate_all(Error **errp); @@ -208,8 +209,8 @@ typedef struct BdrvNextIterator { BlockDriverState *bs; } BdrvNextIterator; -BlockDriverState *bdrv_first(BdrvNextIterator *it); -BlockDriverState *bdrv_next(BdrvNextIterator *it); +BlockDriverState * GRAPH_RDLOCK bdrv_first(BdrvNextIterator *it); +BlockDriverState * GRAPH_RDLOCK bdrv_next(BdrvNextIterator *it); void bdrv_next_cleanup(BdrvNextIterator *it); BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs); diff --git a/include/sysemu/block-backend-global-state.h b/include/sysemu/block-backend-global-state.h index d5f675493a..49c12b0fa9 100644 --- a/include/sysemu/block-backend-global-state.h +++ b/include/sysemu/block-backend-global-state.h @@ -59,8 +59,8 @@ BlockBackend *blk_by_public(BlockBackendPublic *public); void blk_remove_bs(BlockBackend *blk); int blk_insert_bs(BlockBackend *blk, BlockDriverState *bs, Error **errp); int blk_replace_bs(BlockBackend *blk, BlockDriverState *new_bs, Error **errp); -bool bdrv_has_blk(BlockDriverState *bs); -bool bdrv_is_root_node(BlockDriverState *bs); +bool GRAPH_RDLOCK bdrv_has_blk(BlockDriverState *bs); +bool GRAPH_RDLOCK bdrv_is_root_node(BlockDriverState *bs); int GRAPH_UNLOCKED blk_set_perm(BlockBackend *blk, uint64_t perm, uint64_t shared_perm, Error **errp); void blk_get_perm(BlockBackend *blk, uint64_t *perm, uint64_t *shared_perm); diff --git a/migration/block.c b/migration/block.c index 5f930870a5..d115e1cfa5 100644 --- a/migration/block.c +++ b/migration/block.c @@ -388,6 +388,8 @@ static int init_blk_migration(QEMUFile *f) Error *local_err = NULL; int ret; + GRAPH_RDLOCK_GUARD_MAINLOOP(); + block_mig_state.submitted = 0; block_mig_state.read_done = 0; block_mig_state.transferred = 0; diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c index c115ef2d23..5b25ba24f7 100644 --- a/migration/migration-hmp-cmds.c +++ b/migration/migration-hmp-cmds.c @@ -794,6 +794,8 @@ static void vm_completion(ReadLineState *rs, const char *str) BlockDriverState *bs; BdrvNextIterator it; + GRAPH_RDLOCK_GUARD_MAINLOOP(); + len = strlen(str); readline_set_completion_index(rs, len); diff --git a/tests/unit/test-block-iothread.c b/tests/unit/test-block-iothread.c index 9155547313..151049bda5 100644 --- a/tests/unit/test-block-iothread.c +++ b/tests/unit/test-block-iothread.c @@ -383,6 +383,9 @@ static void test_sync_op_check(BdrvChild *c) static void test_sync_op_activate(BdrvChild *c) { + GLOBAL_STATE_CODE(); + GRAPH_RDLOCK_GUARD_MAINLOOP(); + /* Early success: Image is not inactive */ bdrv_activate(c->bs, NULL); } -- 2.11.4.GIT