[RFC PATCH 64/79] mm/buffer: use _page_has_buffers() instead of page_has_buffers()

[jglisse]

From: Jérôme Glisse <jgli...@redhat.com>

The former need the address_space for which the buffer_head is being
lookup.

----------------------------------------------------------------------
@exists@
identifier M;
expression E;
@@
struct address_space *M;
...
-page_buffers(E)
+_page_buffers(E, M)

@exists@
identifier M, F;
expression E;
@@
F(..., struct address_space *M, ...) {...
-page_buffers(E)
+_page_buffers(E, M)
...}

@exists@
identifier M;
expression E;
@@
struct address_space *M;
...
-page_has_buffers(E)
+_page_has_buffers(E, M)

@exists@
identifier M, F;
expression E;
@@
F(..., struct address_space *M, ...) {...
-page_has_buffers(E)
+_page_has_buffers(E, M)
...}

@exists@
identifier I;
expression E;
@@
struct inode *I;
...
-page_buffers(E)
+_page_buffers(E, I->i_mapping)

@exists@
identifier I, F;
expression E;
@@
F(..., struct inode *I, ...) {...
-page_buffers(E)
+_page_buffers(E, I->i_mapping)
...}

@exists@
identifier I;
expression E;
@@
struct inode *I;
...
-page_has_buffers(E)
+_page_has_buffers(E, I->i_mapping)

@exists@
identifier I, F;
expression E;
@@
F(..., struct inode *I, ...) {...
-page_has_buffers(E)
+_page_has_buffers(E, I->i_mapping)
...}
----------------------------------------------------------------------

Signed-off-by: Jérôme Glisse <jgli...@redhat.com>
CC: Andrew Morton <a...@linux-foundation.org>
Cc: Alexander Viro <v...@zeniv.linux.org.uk>
Cc: linux-fsde...@vger.kernel.org
Cc: Jens Axboe <ax...@kernel.dk>
Cc: Tejun Heo <t...@kernel.org>
Cc: Jan Kara <j...@suse.cz>
Cc: Josef Bacik <jba...@fb.com>
Cc: Mel Gorman <mgor...@techsingularity.net>
---
 mm/migrate.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index c2a613283fa2..e4b20ac6cf36 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -768,10 +768,10 @@ int buffer_migrate_page(struct address_space *mapping,
        struct buffer_head *bh, *head;
        int rc;
 
-       if (!page_has_buffers(page))
+       if (!_page_has_buffers(page, mapping))
                return migrate_page(mapping, newpage, page, mode);
 
-       head = page_buffers(page);
+       head = _page_buffers(page, mapping);
 
        rc = migrate_page_move_mapping(mapping, newpage, page, head, mode, 0);
 
-- 
2.14.3