diff options
| author | Chunwei Chen <[email protected]> | 2016-07-14 17:31:00 -0700 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2016-07-19 09:23:58 -0700 |
| commit | 1d9b3bd8fb2b633b7523d9f39149d76e24ffb535 (patch) | |
| tree | 89134ceb0c3809b4c9128da4c27d009705d1d7a2 /module/zfs | |
| parent | b756ff2445e932a48b3a8a33ca6a0df630c8fc15 (diff) | |
Wait iput_async before evict_inodes to prevent race
Wait for iput_async before entering evict_inodes in
generic_shutdown_super. The reason we must finish before
evict_inodes is when lazytime is on, or when zfs_purgedir calls
zfs_zget, iput would bump i_count from 0 to 1. This would race
with the i_count check in evict_inodes. This means it could
destroy the inode while we are still using it.
Signed-off-by: Chunwei Chen <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #4854
Diffstat (limited to 'module/zfs')
| -rw-r--r-- | module/zfs/zfs_vfsops.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/module/zfs/zfs_vfsops.c b/module/zfs/zfs_vfsops.c index 3c9a8476c..2f1f44207 100644 --- a/module/zfs/zfs_vfsops.c +++ b/module/zfs/zfs_vfsops.c @@ -1415,6 +1415,24 @@ zfs_preumount(struct super_block *sb) if (zsb) zfsctl_destroy(sb->s_fs_info); + /* + * Wait for iput_async before entering evict_inodes in + * generic_shutdown_super. The reason we must finish before + * evict_inodes is when lazytime is on, or when zfs_purgedir calls + * zfs_zget, iput would bump i_count from 0 to 1. This would race + * with the i_count check in evict_inodes. This means it could + * destroy the inode while we are still using it. + * + * We wait for two passes. xattr directories in the first pass may + * add xattr entries in zfs_purgedir, so in the second pass we wait + * for them. We don't use taskq_wait here because it is a pool wide + * taskq. Other mounted filesystems can constantly do iput_async + * and there's no guarantee when taskq will be empty. + */ + taskq_wait_outstanding(dsl_pool_iput_taskq( + dmu_objset_pool(zsb->z_os)), 0); + taskq_wait_outstanding(dsl_pool_iput_taskq( + dmu_objset_pool(zsb->z_os)), 0); } EXPORT_SYMBOL(zfs_preumount); |