diff options
| author | avg <avg@FreeBSD.org> | 2017-09-19 08:57:19 +0000 |
|---|---|---|
| committer | avg <avg@FreeBSD.org> | 2017-09-19 08:57:19 +0000 |
| commit | 6a9788f07ec60dc8c24e8b7babd406b6b63022de (patch) | |
| tree | e8ac009a992e2aef56bd4ad93028738293d87bc6 | |
| parent | 2c42741fe40e2fcdc138a520abb615ee745c4856 (diff) | |
| download | FreeBSD-src-6a9788f07ec60dc8c24e8b7babd406b6b63022de.zip FreeBSD-src-6a9788f07ec60dc8c24e8b7babd406b6b63022de.tar.gz | |
MFC r322237: MFV r322236: 8126 ztest assertion failed in dbuf_dirty due to dn_nlevels changing
illumos/illumos-gate@dcb6872c565819ac88acbc2ece999ef241c8b982
https://github.com/illumos/illumos-gate/commit/dcb6872c565819ac88acbc2ece999ef241c8b982
https://www.illumos.org/issues/8126
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.
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Serapheim Dimitropoulos <serapheim@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Author: Matthew Ahrens <mahrens@delphix.com>
| -rw-r--r-- | sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dbuf.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dbuf.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dbuf.c index c077168..fbacd8c 100644 --- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dbuf.c +++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dbuf.c @@ -1542,11 +1542,6 @@ 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 @@ -1664,6 +1659,16 @@ 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 |
