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Commit 6afdb859 authored by Michal Hocko's avatar Michal Hocko Committed by Linus Torvalds
Browse files

mm: do not ignore mapping_gfp_mask in page cache allocation paths 



page_cache_read, do_generic_file_read, __generic_file_splice_read and
__ntfs_grab_cache_pages currently ignore mapping_gfp_mask when calling
add_to_page_cache_lru which might cause recursion into fs down in the
direct reclaim path if the mapping really relies on GFP_NOFS semantic.

This doesn't seem to be the case now because page_cache_read (page fault
path) doesn't seem to suffer from the reclaim recursion issues and
do_generic_file_read and __generic_file_splice_read also shouldn't be
called under fs locks which would deadlock in the reclaim path.  Anyway it
is better to obey mapping gfp mask and prevent from later breakage.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: default avatarMichal Hocko <mhocko@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Anton Altaparmakov <anton@tuxera.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0f96ae29

fs/ntfs/file.c

+2 −1
Original line number Diff line number Diff line
@@ -525,7 +525,8 @@ static inline int __ntfs_grab_cache_pages(struct address_space *mapping, 
				}

			}

			err = add_to_page_cache_lru(*cached_page, mapping,

					index, GFP_KERNEL);

					index,

					GFP_KERNEL & mapping_gfp_mask(mapping));

			if (unlikely(err)) {

				if (err == -EEXIST)

					continue;

fs/splice.c

+1 −1
Original line number Diff line number Diff line
@@ -359,7 +359,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos, 
				break;



			error = add_to_page_cache_lru(page, mapping, index,

						GFP_KERNEL);

					GFP_KERNEL & mapping_gfp_mask(mapping));

			if (unlikely(error)) {

				page_cache_release(page);

				if (error == -EEXIST)

mm/filemap.c

+4 −3
Original line number Diff line number Diff line
@@ -1664,8 +1664,8 @@ static ssize_t do_generic_file_read(struct file *filp, loff_t *ppos, 
			error = -ENOMEM;

			goto out;

		}

		error = add_to_page_cache_lru(page, mapping,

						index, GFP_KERNEL);

		error = add_to_page_cache_lru(page, mapping, index,

					GFP_KERNEL & mapping_gfp_mask(mapping));

		if (error) {

			page_cache_release(page);

			if (error == -EEXIST) {
@@ -1766,7 +1766,8 @@ static int page_cache_read(struct file *file, pgoff_t offset) 
		if (!page)

			return -ENOMEM;



		ret = add_to_page_cache_lru(page, mapping, offset, GFP_KERNEL);

		ret = add_to_page_cache_lru(page, mapping, offset,

				GFP_KERNEL & mapping_gfp_mask(mapping));

		if (ret == 0)

			ret = mapping->a_ops->readpage(file, page);

		else if (ret == -EEXIST)