diff options
| author | Chunwei Chen <[email protected]> | 2015-12-18 11:39:41 -0800 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2015-12-28 09:41:30 -0800 |
| commit | 29572ccdeff7ddb1211b0f26dea69e0a2f262faf (patch) | |
| tree | 42c5bf7b849d47a8029e94ed49484eecd73af003 /module | |
| parent | 2ebc7b72b3989ac53c1753f79eaf71d95419c103 (diff) | |
Fix empty xattr dir causing lockup
During zfs_rmnode on a xattr dir, if the system crash just after
dmu_free_long_range, we would get empty xattr dir in delete queue. This would
cause blkid=0 be passed into zap_get_leaf_byblk when doing zfs_purgedir during
mount, and would try to do rw_enter on a wrong structure and cause system
lockup.
We fix this by returning ENOENT when blkid is zero in zap_get_leaf_byblk.
Signed-off-by: Chunwei Chen <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #4114
Closes #4052
Closes #4006
Closes #3018
Closes #2861
Diffstat (limited to 'module')
| -rw-r--r-- | module/zfs/zap.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/module/zfs/zap.c b/module/zfs/zap.c index 4640fb98c..cf0b92c7d 100644 --- a/module/zfs/zap.c +++ b/module/zfs/zap.c @@ -504,6 +504,16 @@ zap_get_leaf_byblk(zap_t *zap, uint64_t blkid, dmu_tx_t *tx, krw_t lt, ASSERT(RW_LOCK_HELD(&zap->zap_rwlock)); + /* + * If system crashed just after dmu_free_long_range in zfs_rmnode, we + * would be left with an empty xattr dir in delete queue. blkid=0 + * would be passed in when doing zfs_purgedir. If that's the case we + * should just return immediately. The underlying objects should + * already be freed, so this should be perfectly fine. + */ + if (blkid == 0) + return (ENOENT); + err = dmu_buf_hold(zap->zap_objset, zap->zap_object, blkid << bs, NULL, &db, DMU_READ_NO_PREFETCH); if (err) |