diff options
| author | Brian Behlendorf <[email protected]> | 2014-01-08 10:25:42 -0800 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2014-01-09 15:54:08 -0800 |
| commit | fd23720ae14dca926800ae70e6c8f4b4f82efc08 (patch) | |
| tree | 3acde6613c84ed21c324f155445f36f0b0891639 /module/zfs/zfs_vfsops.c | |
| parent | 4fcc43790c872139a2e318ebe4100e8404f841c0 (diff) | |
Drain iput taskq outside z_teardown_lock
It's unsafe to drain the iput taskq while holding the z_teardown_lock
as a writer. This is because when the last reference on an inode is
dropped it may still have pages which need to be written to disk.
This will be done through zpl_writepages which will acquire the
z_teardown_lock as a reader in ZFS_ENTER. Therefore, if we're
holding the lock as a writer in zfs_sb_teardown the unmount will
deadlock.
Signed-off-by: Brian Behlendorf <[email protected]>
Signed-off-by: Chris Dunlop <[email protected]>
Closes #1988
Diffstat (limited to 'module/zfs/zfs_vfsops.c')
| -rw-r--r-- | module/zfs/zfs_vfsops.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/module/zfs/zfs_vfsops.c b/module/zfs/zfs_vfsops.c index c64854d7b..f331a36ea 100644 --- a/module/zfs/zfs_vfsops.c +++ b/module/zfs/zfs_vfsops.c @@ -1091,6 +1091,14 @@ zfs_sb_teardown(zfs_sb_t *zsb, boolean_t unmounting) { znode_t *zp; + /* + * If someone has not already unmounted this file system, + * drain the iput_taskq to ensure all active references to the + * zfs_sb_t have been handled only then can it be safely destroyed. + */ + if (zsb->z_os) + taskq_wait(dsl_pool_iput_taskq(dmu_objset_pool(zsb->z_os))); + rrw_enter(&zsb->z_teardown_lock, RW_WRITER, FTAG); if (!unmounting) { @@ -1105,14 +1113,6 @@ zfs_sb_teardown(zfs_sb_t *zsb, boolean_t unmounting) } /* - * If someone has not already unmounted this file system, - * drain the iput_taskq to ensure all active references to the - * zfs_sb_t have been handled only then can it be safely destroyed. - */ - if (zsb->z_os) - taskq_wait(dsl_pool_iput_taskq(dmu_objset_pool(zsb->z_os))); - - /* * Close the zil. NB: Can't close the zil while zfs_inactive * threads are blocked as zil_close can call zfs_inactive. */ |