From c626d174cfe38e7f0545d074c299527892cd8c45 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Mon, 6 Apr 2009 18:42:11 +0200 Subject: xfs: prevent unwritten extent conversion from blocking I/O completion Unwritten extent conversion can recurse back into the filesystem due to memory allocation. Memory reclaim requires I/O completions to be processed to allow the callers to make progress. If the I/O completion workqueue thread is doing the recursion, then we have a deadlock situation. Move unwritten extent completion into it's own workqueue so it doesn't block I/O completions for normal delayed allocation or overwrite data. Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig --- fs/xfs/linux-2.6/xfs_aops.c | 38 +++++++++++++++++++++----------------- 1 file changed, 21 insertions(+), 17 deletions(-) (limited to 'fs/xfs/linux-2.6/xfs_aops.c') diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c index c13f67300fe..7ec89fc05b2 100644 --- a/fs/xfs/linux-2.6/xfs_aops.c +++ b/fs/xfs/linux-2.6/xfs_aops.c @@ -152,23 +152,6 @@ xfs_find_bdev_for_inode( return mp->m_ddev_targp->bt_bdev; } -/* - * Schedule IO completion handling on a xfsdatad if this was - * the final hold on this ioend. If we are asked to wait, - * flush the workqueue. - */ -STATIC void -xfs_finish_ioend( - xfs_ioend_t *ioend, - int wait) -{ - if (atomic_dec_and_test(&ioend->io_remaining)) { - queue_work(xfsdatad_workqueue, &ioend->io_work); - if (wait) - flush_workqueue(xfsdatad_workqueue); - } -} - /* * We're now finished for good with this ioend structure. * Update the page state via the associated buffer_heads, @@ -309,6 +292,27 @@ xfs_end_bio_read( xfs_destroy_ioend(ioend); } +/* + * Schedule IO completion handling on a xfsdatad if this was + * the final hold on this ioend. If we are asked to wait, + * flush the workqueue. + */ +STATIC void +xfs_finish_ioend( + xfs_ioend_t *ioend, + int wait) +{ + if (atomic_dec_and_test(&ioend->io_remaining)) { + struct workqueue_struct *wq = xfsdatad_workqueue; + if (ioend->io_work.func == xfs_end_bio_unwritten) + wq = xfsconvertd_workqueue; + + queue_work(wq, &ioend->io_work); + if (wait) + flush_workqueue(wq); + } +} + /* * Allocate and initialise an IO completion structure. * We need to track unwritten extent write completion here initially. -- cgit v1.2.3