Commit ff9a28f6 authored Mar 14, 2013 by Jan Kara Committed by Ben Myers Mar 22, 2013

xfs: Fix WARN_ON(delalloc) in xfs_vm_releasepage()



When a dirty page is truncated from a file but reclaim gets to it before
truncate_inode_pages(), we hit WARN_ON(delalloc) in
xfs_vm_releasepage(). This is because reclaim tries to write the page,
xfs_vm_writepage() just bails out (leaving page clean) and thus reclaim
thinks it can continue and calls xfs_vm_releasepage() on page with dirty
buffers.

Fix the issue by redirtying the page in xfs_vm_writepage(). This makes
reclaim stop reclaiming the page and also logically it keeps page in a
more consistent state where page with dirty buffers has PageDirty set.

Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

parent 19cb7e38

fs/xfs/xfs_aops.c

+6 −6

Original line number	Diff line number	Diff line
		@@ -953,13 +953,13 @@ xfs_vm_writepage(
		unsigned offset_into_page = offset & (PAGE_CACHE_SIZE - 1);

		/*
		* Just skip the page if it is fully outside i_size, e.g. due
		* to a truncate operation that is in progress.
		* Skip the page if it is fully outside i_size, e.g. due to a
		* truncate operation that is in progress. We must redirty the
		* page so that reclaim stops reclaiming it. Otherwise
		* xfs_vm_releasepage() is called on it and gets confused.
		*/
		if (page->index >= end_index + 1 \|\| offset_into_page == 0) {
		unlock_page(page);
		return 0;
		}
		if (page->index >= end_index + 1 \|\| offset_into_page == 0)
		goto redirty;

		/*
		* The page straddles i_size. It must be zeroed out on each

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