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| author | Alexander Motin <mav@FreeBSD.org> | 2024-05-23 16:20:37 +0000 |
|---|---|---|
| committer | Alexander Motin <mav@FreeBSD.org> | 2024-05-23 17:43:02 +0000 |
| commit | 9898f936aa69d1b67bcd83d189acb6013f76bd43 (patch) | |
| tree | 9be19527047ac27cac9ccb4e56b460a6f838b627 | |
| parent | d823e80ef5a709ee8c1f9e138eedcda6c1cbd1b5 (diff) | |
| download | src-9898f936aa69d1b67bcd83d189acb6013f76bd43.tar.gz src-9898f936aa69d1b67bcd83d189acb6013f76bd43.zip | |
Fix scn_queue races on very old pools
Code for pools before version 11 uses dmu_objset_find_dp() to scan
for children datasets/clones. It calls enqueue_clones_cb() and
enqueue_cb() callbacks in parallel from multiple taskq threads.
It ends up bad for scan_ds_queue_insert(), corrupting scn_queue
AVL-tree. Fix it by introducing a mutex to protect those two
scan_ds_queue_insert() calls. All other calls are done from the
sync thread and so serialized.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes #16162
PR: 278414
(cherry picked from commit 49086aa35d987b78dbc3c9ec94814fe338e07164)
| -rw-r--r-- | sys/contrib/openzfs/include/sys/dsl_scan.h | 1 | ||||
| -rw-r--r-- | sys/contrib/openzfs/module/zfs/dsl_scan.c | 6 |
2 files changed, 7 insertions, 0 deletions
diff --git a/sys/contrib/openzfs/include/sys/dsl_scan.h b/sys/contrib/openzfs/include/sys/dsl_scan.h index d716510f879d..f2647a936c94 100644 --- a/sys/contrib/openzfs/include/sys/dsl_scan.h +++ b/sys/contrib/openzfs/include/sys/dsl_scan.h @@ -155,6 +155,7 @@ typedef struct dsl_scan { dsl_scan_phys_t scn_phys; /* on disk representation of scan */ dsl_scan_phys_t scn_phys_cached; avl_tree_t scn_queue; /* queue of datasets to scan */ + kmutex_t scn_queue_lock; /* serializes scn_queue inserts */ uint64_t scn_queues_pending; /* outstanding data to issue */ } dsl_scan_t; diff --git a/sys/contrib/openzfs/module/zfs/dsl_scan.c b/sys/contrib/openzfs/module/zfs/dsl_scan.c index f0a851ff53a9..6979f08cc9ff 100644 --- a/sys/contrib/openzfs/module/zfs/dsl_scan.c +++ b/sys/contrib/openzfs/module/zfs/dsl_scan.c @@ -469,6 +469,7 @@ dsl_scan_init(dsl_pool_t *dp, uint64_t txg) avl_create(&scn->scn_queue, scan_ds_queue_compare, sizeof (scan_ds_t), offsetof(scan_ds_t, sds_node)); + mutex_init(&scn->scn_queue_lock, NULL, MUTEX_DEFAULT, NULL); avl_create(&scn->scn_prefetch_queue, scan_prefetch_queue_compare, sizeof (scan_prefetch_issue_ctx_t), offsetof(scan_prefetch_issue_ctx_t, spic_avl_node)); @@ -611,6 +612,7 @@ dsl_scan_fini(dsl_pool_t *dp) scan_ds_queue_clear(scn); avl_destroy(&scn->scn_queue); + mutex_destroy(&scn->scn_queue_lock); scan_ds_prefetch_queue_clear(scn); avl_destroy(&scn->scn_prefetch_queue); @@ -2402,8 +2404,10 @@ enqueue_clones_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg) return (err); ds = prev; } + mutex_enter(&scn->scn_queue_lock); scan_ds_queue_insert(scn, ds->ds_object, dsl_dataset_phys(ds)->ds_prev_snap_txg); + mutex_exit(&scn->scn_queue_lock); dsl_dataset_rele(ds, FTAG); return (0); } @@ -2593,8 +2597,10 @@ enqueue_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg) ds = prev; } + mutex_enter(&scn->scn_queue_lock); scan_ds_queue_insert(scn, ds->ds_object, dsl_dataset_phys(ds)->ds_prev_snap_txg); + mutex_exit(&scn->scn_queue_lock); dsl_dataset_rele(ds, FTAG); return (0); } |