diff options
| author | Mark Tinguely <tinguely@sgi.com> | 2012-07-24 10:59:19 -0500 |
|---|---|---|
| committer | Ben Myers <bpm@sgi.com> | 2012-07-29 16:34:19 -0500 |
| commit | 9a57fa8ee7c29e11c2a29ce058573ba99157eda7 (patch) | |
| tree | 3fc564a3ad53b16a6604aa89ae3d4d26e07e2d38 | |
| parent | 8375f922aaa6e7a880022529202fb486315568c3 (diff) | |
xfs: wait for the write the superblock on unmount
v2: Add the xfs_buf_lock to xfs_quiesce_attr().
Add explaination why xfs_buf_lock() is used to wait for write.
xfs_wait_buftarg() does not wait for the completion of the write of the
uncached superblock. This write can race with the shutdown of the log
and causes a panic if the write does not win the race.
During the log write, xfsaild_push() will lock the buffer and set the
XBF_ASYNC flag. Because the XBF_FLAG is set, complete() is not performed
on the buffer's iowait entry, we cannot call xfs_buf_iowait() to wait
for the write to complete. The buffer's lock is held until the write is
complete, so we can block on a xfs_buf_lock() request to be notified
that the write is complete.
Signed-off-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
| -rw-r--r-- | fs/xfs/xfs_mount.c | 9 | ||||
| -rw-r--r-- | fs/xfs/xfs_sync.c | 9 |
2 files changed, 18 insertions, 0 deletions
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c index 9536fd19019..711ca51ca3d 100644 --- a/fs/xfs/xfs_mount.c +++ b/fs/xfs/xfs_mount.c @@ -1529,6 +1529,15 @@ xfs_unmountfs( xfs_ail_push_all_sync(mp->m_ail); xfs_wait_buftarg(mp->m_ddev_targp); + /* + * The superblock buffer is uncached and xfsaild_push() will lock and + * set the XBF_ASYNC flag on the buffer. We cannot do xfs_buf_iowait() + * here but a lock on the superblock buffer will block until iodone() + * has completed. + */ + xfs_buf_lock(mp->m_sb_bp); + xfs_buf_unlock(mp->m_sb_bp); + xfs_log_unmount_write(mp); xfs_log_unmount(mp); xfs_uuid_unmount(mp); diff --git a/fs/xfs/xfs_sync.c b/fs/xfs/xfs_sync.c index e61fc151907..97304f10e78 100644 --- a/fs/xfs/xfs_sync.c +++ b/fs/xfs/xfs_sync.c @@ -359,6 +359,15 @@ xfs_quiesce_attr( * added an item to the AIL, thus flush it again. */ xfs_ail_push_all_sync(mp->m_ail); + + /* + * The superblock buffer is uncached and xfsaild_push() will lock and + * set the XBF_ASYNC flag on the buffer. We cannot do xfs_buf_iowait() + * here but a lock on the superblock buffer will block until iodone() + * has completed. + */ + xfs_buf_lock(mp->m_sb_bp); + xfs_buf_unlock(mp->m_sb_bp); } static void |