Commit 94054fa3 authored Oct 31, 2011 by Mel Gorman Committed by Linus Torvalds Oct 31, 2011

xfs: warn if direct reclaim tries to writeback pages



Direct reclaim should never writeback pages.  For now, handle the
situation and warn about it.  Ultimately, this will be a BUG_ON.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Alex Elder <aelder@sgi.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent a18bba06

fs/xfs/xfs_aops.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -902,11 +902,11 @@ xfs_vm_writepage(
		* random callers for direct reclaim or memcg reclaim. We explicitly
		* allow reclaim from kswapd as the stack usage there is relatively low.
		*
		* This should really be done by the core VM, but until that happens
		* filesystems like XFS, btrfs and ext4 have to take care of this
		* by themselves.
		* This should never happen except in the case of a VM regression so
		* warn about it.
		*/
		if ((current->flags & (PF_MEMALLOC\|PF_KSWAPD)) == PF_MEMALLOC)
		if (WARN_ON_ONCE((current->flags & (PF_MEMALLOC\|PF_KSWAPD)) ==
		PF_MEMALLOC))
		goto redirty;

		/*