mm, fs: introduce mapping_gfp_constraint()

There are many places which use mapping_gfp_mask to restrict a more
generic gfp mask which would be used for allocations which are not
directly related to the page cache but they are performed in the same
context.

Let's introduce a helper function which makes the restriction explicit and
easier to track.  This patch doesn't introduce any functional changes.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/mpage.c b/fs/mpage.c
index 09abba7653aa..1480d3a18037 100644
--- a/fs/mpage.c
+++ b/fs/mpage.c
@@ -361,7 +361,7 @@ mpage_readpages(struct address_space *mapping, struct list_head *pages,
         sector_t last_block_in_bio = 0;
         struct buffer_head map_bh;
         unsigned long first_logical_block = 0;
-        gfp_t gfp = GFP_KERNEL & mapping_gfp_mask(mapping);
+        gfp_t gfp = mapping_gfp_constraint(mapping, GFP_KERNEL);
 
         map_bh.b_state = 0;
         map_bh.b_size = 0;
@@ -397,7 +397,7 @@ int mpage_readpage(struct page *page, get_block_t get_block)
         sector_t last_block_in_bio = 0;
         struct buffer_head map_bh;
         unsigned long first_logical_block = 0;
-        gfp_t gfp = GFP_KERNEL & mapping_gfp_mask(page->mapping);
+        gfp_t gfp = mapping_gfp_constraint(page->mapping, GFP_KERNEL);
 
         map_bh.b_state = 0;
         map_bh.b_size = 0;