Commit 23539afc authored by Wu Fengguang's avatar Wu Fengguang Committed by Linus Torvalds
Browse files

writeback: don't redirty tail an inode with dirty pages 



Avoid delaying writeback for an expire inode with lots of dirty pages, but
no active dirtier at the moment.  Previously we only do that for the
kupdate case.

Any filesystem that does delayed allocation or unwritten extent conversion
after IO completion will cause this - for example, XFS.

Signed-off-by: default avatarWu Fengguang <fengguang.wu@intel.com>
Acked-by: default avatarJan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 1babe183

fs/fs-writeback.c

+9 −13
Original line number Diff line number Diff line
@@ -363,18 +363,7 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) 
	spin_lock(&inode_lock);

	inode->i_state &= ~I_SYNC;

	if (!(inode->i_state & I_FREEING)) {

		if ((inode->i_state & I_DIRTY_PAGES) && wbc->for_kupdate) {

			/*

			 * More pages get dirtied by a fast dirtier.

			 */

			goto select_queue;

		} else if (inode->i_state & I_DIRTY) {

			/*

			 * At least XFS will redirty the inode during the

			 * writeback (delalloc) and on io completion (isize).

			 */

			redirty_tail(inode);

		} else if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) {

		if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) {

			/*

			 * We didn't write back all the pages.  nfs_writepages()

			 * sometimes bales out without doing anything. Redirty
@@ -396,7 +385,6 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) 
				 * soon as the queue becomes uncongested.

				 */

				inode->i_state |= I_DIRTY_PAGES;

select_queue:

				if (wbc->nr_to_write <= 0) {

					/*

					 * slice used up: queue for next turn
@@ -419,6 +407,14 @@ select_queue: 
				inode->i_state |= I_DIRTY_PAGES;

				redirty_tail(inode);

			}

		} else if (inode->i_state & I_DIRTY) {

			/*

			 * Filesystems can dirty the inode during writeback

			 * operations, such as delayed allocation during

			 * submission or metadata updates after data IO

			 * completion.

			 */

			redirty_tail(inode);

		} else if (atomic_read(&inode->i_count)) {

			/*

			 * The inode is clean, inuse

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