vmscan: change shrinker API by passing shrink_control struct

Change each shrinker's API by consolidating the existing parameters into
shrink_control struct.  This will simplify any further features added w/o
touching each file of shrinker.

[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: fix warning]
[kosaki.motohiro@jp.fujitsu.com: fix up new shrinker API]
[akpm@linux-foundation.org: fix xfs warning]
[akpm@linux-foundation.org: update gfs2]
Signed-off-by: Ying Han <yinghan@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 4 deletions

diff --git a/fs/mbcache.c b/fs/mbcache.c
index 2f174be06555..8c32ef3ba88e 100644
--- a/fs/mbcache.c
+++ b/fs/mbcache.c
@@ -90,7 +90,8 @@ static DEFINE_SPINLOCK(mb_cache_spinlock);
  * What the mbcache registers as to get shrunk dynamically.
  */
 
-static int mb_cache_shrink_fn(struct shrinker *shrink, int nr_to_scan, gfp_t gfp_mask);
+static int mb_cache_shrink_fn(struct shrinker *shrink,
+                              struct shrink_control *sc);
 
 static struct shrinker mb_cache_shrinker = {
         .shrink = mb_cache_shrink_fn,
@@ -156,18 +157,19 @@ forget:
  * gets low.
  *
  * @shrink: (ignored)
- * @nr_to_scan: Number of objects to scan
- * @gfp_mask: (ignored)
+ * @sc: shrink_control passed from reclaim
  *
  * Returns the number of objects which are present in the cache.
  */
 static int
-mb_cache_shrink_fn(struct shrinker *shrink, int nr_to_scan, gfp_t gfp_mask)
+mb_cache_shrink_fn(struct shrinker *shrink, struct shrink_control *sc)
 {
         LIST_HEAD(free_list);
         struct mb_cache *cache;
         struct mb_cache_entry *entry, *tmp;
         int count = 0;
+        int nr_to_scan = sc->nr_to_scan;
+        gfp_t gfp_mask = sc->gfp_mask;
 
         mb_debug("trying to free %d entries", nr_to_scan);
         spin_lock(&mb_cache_spinlock);