From 211e4d434bd737be38aabad0247ce3da9964370e Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 23 Apr 2012 15:58:34 +1000 Subject: xfs: implement freezing by emptying the AIL Now that we write back all metadata either synchronously or through the AIL we can simply implement metadata freezing in terms of emptying the AIL. The implementation for this is fairly simply and straight-forward: A new routine is added that asks the xfsaild to push the AIL to the end and waits for it to complete and send a wakeup. The routine will then loop if the AIL is not actually empty, and continue to do so until the AIL is compeltely empty. We keep an inode reclaim pass in the freeze process to avoid having memory pressure have to reclaim inodes that require dirtying the filesystem to be reclaimed after the freeze has completed. This means we can also treat unmount in the exact same way as freeze. As an upside we can now remove the radix tree based inode writeback and xfs_unmountfs_writesb. [ Dave Chinner: - Cleaned up commit message. - Added inode reclaim passes back into freeze. - Cleaned up wakeup mechanism to avoid the use of a new sleep counter variable. ] Signed-off-by: Christoph Hellwig Signed-off-by: Dave Chinner Reviewed-by: Mark Tinguely Signed-off-by: Ben Myers --- fs/xfs/xfs_trans_ail.c | 36 +++++++++++++++++++++++++++++------- 1 file changed, 29 insertions(+), 7 deletions(-) (limited to 'fs/xfs/xfs_trans_ail.c') diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c index 77acc53f2f31..0425ca16738b 100644 --- a/fs/xfs/xfs_trans_ail.c +++ b/fs/xfs/xfs_trans_ail.c @@ -383,9 +383,8 @@ xfsaild_push( spin_lock(&ailp->xa_lock); } - target = ailp->xa_target; lip = xfs_trans_ail_cursor_first(ailp, &cur, ailp->xa_last_pushed_lsn); - if (!lip || XFS_FORCED_SHUTDOWN(mp)) { + if (!lip) { /* * AIL is empty or our push has reached the end. */ @@ -408,6 +407,7 @@ xfsaild_push( * lots of contention on the AIL lists. */ lsn = lip->li_lsn; + target = ailp->xa_target; while ((XFS_LSN_CMP(lip->li_lsn, target) <= 0)) { int lock_result; /* @@ -466,11 +466,6 @@ xfsaild_push( } spin_lock(&ailp->xa_lock); - /* should we bother continuing? */ - if (XFS_FORCED_SHUTDOWN(mp)) - break; - ASSERT(mp->m_log); - count++; /* @@ -610,6 +605,30 @@ xfs_ail_push_all( xfs_ail_push(ailp, threshold_lsn); } +/* + * Push out all items in the AIL immediately and wait until the AIL is empty. + */ +void +xfs_ail_push_all_sync( + struct xfs_ail *ailp) +{ + struct xfs_log_item *lip; + DEFINE_WAIT(wait); + + spin_lock(&ailp->xa_lock); + while ((lip = xfs_ail_max(ailp)) != NULL) { + prepare_to_wait(&ailp->xa_empty, &wait, TASK_UNINTERRUPTIBLE); + ailp->xa_target = lip->li_lsn; + wake_up_process(ailp->xa_task); + spin_unlock(&ailp->xa_lock); + schedule(); + spin_lock(&ailp->xa_lock); + } + spin_unlock(&ailp->xa_lock); + + finish_wait(&ailp->xa_empty, &wait); +} + /* * xfs_trans_ail_update - bulk AIL insertion operation. * @@ -737,6 +756,8 @@ xfs_trans_ail_delete_bulk( if (mlip_changed) { if (!XFS_FORCED_SHUTDOWN(ailp->xa_mount)) xlog_assign_tail_lsn_locked(ailp->xa_mount); + if (list_empty(&ailp->xa_ail)) + wake_up_all(&ailp->xa_empty); spin_unlock(&ailp->xa_lock); xfs_log_space_wake(ailp->xa_mount); @@ -773,6 +794,7 @@ xfs_trans_ail_init( INIT_LIST_HEAD(&ailp->xa_ail); INIT_LIST_HEAD(&ailp->xa_cursors); spin_lock_init(&ailp->xa_lock); + init_waitqueue_head(&ailp->xa_empty); ailp->xa_task = kthread_run(xfsaild, ailp, "xfsaild/%s", ailp->xa_mount->m_fsname); -- cgit v1.2.3