[patch v4 02/13] [PATCH 02/13] xfs: rationalise xfs_mount_wq users

Ben Myers
2012-10-05T17:18:21Z

[-- Attachment #1: xfs-rationalise-xfs_mount_wq-users.patch --]
[-- Type: text/plain, Size: 5733 bytes --]

From: Dave Chinner <dchinner@redhat.com>

Instead of starting and stopping background work on the xfs_mount_wq
all at the same time, separate them to where they really are needed
to start and stop.

The xfs_sync_worker, only needs to be started after all the mount
processing has completed successfully, while it needs to be stopped
before the log is unmounted.

The xfs_reclaim_worker is started on demand, and can be
stopped before the unmount process does it's own inode reclaim pass.

The xfs_flush_inodes work is run on demand, and so we really only
need to ensure that it has stopped running before we start
processing an unmount, freeze or remount,ro.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>

---
fs/xfs/xfs_mount.c | 6 ++++--
fs/xfs/xfs_super.c | 34 ++++++++++++++--------------------
fs/xfs/xfs_sync.c | 21 +++++----------------
3 files changed, 23 insertions(+), 38 deletions(-)

diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 29c2f83..3152924 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -1483,9 +1483,11 @@ xfs_unmountfs(

/*
* And reclaim all inodes. At this point there should be no dirty
- * inode, and none should be pinned or locked, but use synchronous
- * reclaim just to be sure.
+ * inodes and none should be pinned or locked, but use synchronous
+ * reclaim just to be sure. We can stop background inode reclaim
+ * here as well if it is still running.
*/
+ cancel_delayed_work_sync(&mp->m_reclaim_work);
xfs_reclaim_inodes(mp, SYNC_WAIT);

xfs_qm_unmount(mp);
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 59d76bd..935b2c7 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -918,14 +918,12 @@ xfs_fs_put_super(
{
struct xfs_mount *mp = XFS_M(sb);

- xfs_filestream_unmount(mp);
- cancel_delayed_work_sync(&mp->m_sync_work);
- xfs_unmountfs(mp);
-
cancel_delayed_work_sync(&mp->m_sync_work);
- cancel_delayed_work_sync(&mp->m_reclaim_work);
cancel_work_sync(&mp->m_flush_work);

+ xfs_filestream_unmount(mp);
+ xfs_unmountfs(mp);
+
xfs_freesb(mp);
xfs_icsb_destroy_counters(mp);
xfs_destroy_mount_workqueues(mp);
@@ -1232,6 +1230,9 @@ xfs_fs_fill_super(
spin_lock_init(&mp->m_sb_lock);
mutex_init(&mp->m_growlock);
atomic_set(&mp->m_active_trans, 0);
+ INIT_WORK(&mp->m_flush_work, xfs_flush_worker);
+ INIT_DELAYED_WORK(&mp->m_sync_work, xfs_sync_worker);
+ INIT_DELAYED_WORK(&mp->m_reclaim_work, xfs_reclaim_worker);

mp->m_super = sb;
sb->s_fs_info = mp;
@@ -1295,15 +1296,9 @@ xfs_fs_fill_super(
sb->s_time_gran = 1;
set_posix_acl_flag(sb);

- INIT_WORK(&mp->m_flush_work, xfs_flush_worker);
- INIT_DELAYED_WORK(&mp->m_sync_work, xfs_sync_worker);
- INIT_DELAYED_WORK(&mp->m_reclaim_work, xfs_reclaim_worker);
-
- xfs_syncd_queue_sync(mp);
-
error = xfs_mountfs(mp);
if (error)
- goto out_syncd_stop;
+ goto out_filestream_unmount;

root = igrab(VFS_I(mp->m_rootip));
if (!root) {
@@ -1320,12 +1315,15 @@ xfs_fs_fill_super(
goto out_unmount;
}

+ /*
+ * The filesystem is successfully mounted, so we can start background
+ * sync work now.
+ */
+ xfs_syncd_queue_sync(mp);
+
return 0;
- out_syncd_stop:
- cancel_delayed_work_sync(&mp->m_sync_work);
- cancel_delayed_work_sync(&mp->m_reclaim_work);
- cancel_work_sync(&mp->m_flush_work);

+ out_filestream_unmount:
xfs_filestream_unmount(mp);
out_free_sb:
xfs_freesb(mp);
@@ -1344,10 +1342,6 @@ out_destroy_workqueues:
out_unmount:
xfs_filestream_unmount(mp);
xfs_unmountfs(mp);
-
- cancel_delayed_work_sync(&mp->m_sync_work);
- cancel_delayed_work_sync(&mp->m_reclaim_work);
- cancel_work_sync(&mp->m_flush_work);
goto out_free_sb;
}

diff --git a/fs/xfs/xfs_sync.c b/fs/xfs/xfs_sync.c
index 13830e4..509190f 100644
--- a/fs/xfs/xfs_sync.c
+++ b/fs/xfs/xfs_sync.c
@@ -379,9 +379,9 @@ xfs_syncd_queue_sync(
}

/*
- * Every sync period we need to unpin all items, reclaim inodes and sync
- * disk quotas. We might need to cover the log to indicate that the
- * filesystem is idle and not frozen.
+ * Every sync period we need to unpin all items in the AIL and push them to
+ * disk. If there is nothing dirty, then we might need to cover the log to
+ * indicate that the filesystem is idle and not frozen.
*/
void
xfs_sync_worker(
@@ -391,17 +391,7 @@ xfs_sync_worker(
struct xfs_mount, m_sync_work);
int error;

- /*
- * We shouldn't write/force the log if we are in the mount/unmount
- * process or on a read only filesystem. The workqueue still needs to be
- * active in both cases, however, because it is used for inode reclaim
- * during these times. Use the MS_ACTIVE flag to avoid doing anything
- * during mount. Doing work during unmount is avoided by calling
- * cancel_delayed_work_sync on this work queue before tearing down
- * the ail and the log in xfs_log_unmount.
- */
- if (!(mp->m_super->s_flags & MS_ACTIVE) &&
- !(mp->m_flags & XFS_MOUNT_RDONLY)) {
+ if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
/* dgc: errors ignored here */
if (mp->m_super->s_writers.frozen == SB_UNFROZEN &&
xfs_log_need_covered(mp))
@@ -409,8 +399,7 @@ xfs_sync_worker(
else
xfs_log_force(mp, 0);

- /* start pushing all the metadata that is currently
- * dirty */
+ /* start pushing all the metadata that is currently dirty */
xfs_ail_push_all(mp->m_ail);