mm: do not ignore mapping_gfp_mask in page cache allocation paths
authorMichal Hocko <mhocko@suse.cz>
Wed, 24 Jun 2015 23:58:06 +0000 (16:58 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 25 Jun 2015 00:49:44 +0000 (17:49 -0700)
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: Michal 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/ntfs/file.c
fs/splice.c
mm/filemap.c

index 7bb487e..2cd6536 100644 (file)
@@ -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;
index bfe62ae..0efef17 100644 (file)
@@ -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)
index 519af00..8d17cee 100644 (file)
@@ -1664,8 +1664,8 @@ no_cached_page:
                        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)