diff options
| author | Matthew Ahrens <[email protected]> | 2017-03-20 15:38:11 -0700 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2017-07-07 14:58:33 -0700 |
| commit | 2ade4a99f0b995df6fb45138d04a0209b959ef63 (patch) | |
| tree | 78a602f093a77bb6c8d5421b2da482e5db7b05f8 | |
| parent | a896468c7872dc7277fd0171c65bd2c185bfcaab (diff) | |
OpenZFS 8126 - ztest assertion failed in dbuf_dirty due to dn_nlevels changing
The sync thread is concurrently modifying dn_phys->dn_nlevels
while dbuf_dirty() is trying to assert something about it, without
holding the necessary lock. We need to move this assertion further down
in the function, after we have acquired the dn_struct_rwlock.
Authored by: Matthew Ahrens <[email protected]>
Reviewed by: Pavel Zakharov <[email protected]>
Reviewed by: Serapheim Dimitropoulos <[email protected]>
Approved by: Robert Mustacchi <[email protected]>
Reviewed-by: George Melikov <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Ported-by: Giuseppe Di Natale <[email protected]>
OpenZFS-issue: https://www.illumos.org/issues/8126
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/0ef125d
Closes #6314
| -rw-r--r-- | module/zfs/dbuf.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/module/zfs/dbuf.c b/module/zfs/dbuf.c index f4e24e209..dc2c00495 100644 --- a/module/zfs/dbuf.c +++ b/module/zfs/dbuf.c @@ -1625,11 +1625,6 @@ dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx) (dmu_tx_is_syncing(tx) ? DN_DIRTY_SYNC : DN_DIRTY_OPEN)); ASSERT3U(dn->dn_nlevels, >, db->db_level); - ASSERT((dn->dn_phys->dn_nlevels == 0 && db->db_level == 0) || - dn->dn_phys->dn_nlevels > db->db_level || - dn->dn_next_nlevels[txgoff] > db->db_level || - dn->dn_next_nlevels[(tx->tx_txg-1) & TXG_MASK] > db->db_level || - dn->dn_next_nlevels[(tx->tx_txg-2) & TXG_MASK] > db->db_level); /* * We should only be dirtying in syncing context if it's the @@ -1748,6 +1743,16 @@ dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx) } /* + * We need to hold the dn_struct_rwlock to make this assertion, + * because it protects dn_phys / dn_next_nlevels from changing. + */ + ASSERT((dn->dn_phys->dn_nlevels == 0 && db->db_level == 0) || + dn->dn_phys->dn_nlevels > db->db_level || + dn->dn_next_nlevels[txgoff] > db->db_level || + dn->dn_next_nlevels[(tx->tx_txg-1) & TXG_MASK] > db->db_level || + dn->dn_next_nlevels[(tx->tx_txg-2) & TXG_MASK] > db->db_level); + + /* * If we are overwriting a dedup BP, then unless it is snapshotted, * when we get to syncing context we will need to decrement its * refcount in the DDT. Prefetch the relevant DDT block so that |