shrinker: convert superblock shrinkers to new API

[~andy/linux] / fs / super.c

diff --git a/fs/super.c b/fs/super.c
index 3c5318694ccd4ad365903a7b150da889e3e57449..8aa2660642b97e5c735255448e2d06c099e966e4 100644 (file)
--- a/fs/super.c
+++ b/fs/super.c
@@ -53,11 +53,15 @@ static char *sb_writers_name[SB_FREEZE_LEVELS] = {
  * shrinker path and that leads to deadlock on the shrinker_rwsem. Hence we
  * take a passive reference to the superblock to avoid this from occurring.
  */
-static int prune_super(struct shrinker *shrink, struct shrink_control *sc)
+static unsigned long super_cache_scan(struct shrinker *shrink,
+                                     struct shrink_control *sc)
 {
        struct super_block *sb;
-       int     fs_objects = 0;
-       int     total_objects;
+       long    fs_objects = 0;
+       long    total_objects;
+       long    freed = 0;
+       long    dentries;
+       long    inodes;
 
        sb = container_of(shrink, struct super_block, s_shrink);
 
@@ -65,11 +69,11 @@ static int prune_super(struct shrinker *shrink, struct shrink_control *sc)
         * Deadlock avoidance.  We may hold various FS locks, and we don't want
         * to recurse into the FS that called us in clear_inode() and friends..
         */
-       if (sc->nr_to_scan && !(sc->gfp_mask & __GFP_FS))
-               return -1;
+       if (!(sc->gfp_mask & __GFP_FS))
+               return SHRINK_STOP;
 
        if (!grab_super_passive(sb))
-               return -1;
+               return SHRINK_STOP;
 
        if (sb->s_op->nr_cached_objects)
                fs_objects = sb->s_op->nr_cached_objects(sb);
@@ -77,33 +81,46 @@ static int prune_super(struct shrinker *shrink, struct shrink_control *sc)
        total_objects = sb->s_nr_dentry_unused +
                        sb->s_nr_inodes_unused + fs_objects + 1;
 
-       if (sc->nr_to_scan) {
-               int     dentries;
-               int     inodes;
-
-               /* proportion the scan between the caches */
-               dentries = mult_frac(sc->nr_to_scan, sb->s_nr_dentry_unused,
-                                                       total_objects);
-               inodes = mult_frac(sc->nr_to_scan, sb->s_nr_inodes_unused,
-                                                       total_objects);
-               if (fs_objects)
-                       fs_objects = mult_frac(sc->nr_to_scan, fs_objects,
-                                                       total_objects);
-               /*
-                * prune the dcache first as the icache is pinned by it, then
-                * prune the icache, followed by the filesystem specific caches
-                */
-               prune_dcache_sb(sb, dentries);
-               prune_icache_sb(sb, inodes);
+       /* proportion the scan between the caches */
+       dentries = mult_frac(sc->nr_to_scan, sb->s_nr_dentry_unused,
+                                                               total_objects);
+       inodes = mult_frac(sc->nr_to_scan, sb->s_nr_inodes_unused,
+                                                               total_objects);
 
-               if (fs_objects && sb->s_op->free_cached_objects) {
-                       sb->s_op->free_cached_objects(sb, fs_objects);
-                       fs_objects = sb->s_op->nr_cached_objects(sb);
-               }
-               total_objects = sb->s_nr_dentry_unused +
-                               sb->s_nr_inodes_unused + fs_objects;
+       /*
+        * prune the dcache first as the icache is pinned by it, then
+        * prune the icache, followed by the filesystem specific caches
+        */
+       freed = prune_dcache_sb(sb, dentries);
+       freed += prune_icache_sb(sb, inodes);
+
+       if (fs_objects) {
+               fs_objects = mult_frac(sc->nr_to_scan, fs_objects,
+                                                               total_objects);
+               freed += sb->s_op->free_cached_objects(sb, fs_objects);
        }
 
+       drop_super(sb);
+       return freed;
+}
+
+static unsigned long super_cache_count(struct shrinker *shrink,
+                                      struct shrink_control *sc)
+{
+       struct super_block *sb;
+       long    total_objects = 0;
+
+       sb = container_of(shrink, struct super_block, s_shrink);
+
+       if (!grab_super_passive(sb))
+               return 0;
+
+       if (sb->s_op && sb->s_op->nr_cached_objects)
+               total_objects = sb->s_op->nr_cached_objects(sb);
+
+       total_objects += sb->s_nr_dentry_unused;
+       total_objects += sb->s_nr_inodes_unused;
+
        total_objects = vfs_pressure_ratio(total_objects);
        drop_super(sb);
        return total_objects;
@@ -211,7 +228,8 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
                s->cleancache_poolid = -1;
 
                s->s_shrink.seeks = DEFAULT_SEEKS;
-               s->s_shrink.shrink = prune_super;
+               s->s_shrink.scan_objects = super_cache_scan;
+               s->s_shrink.count_objects = super_cache_count;
                s->s_shrink.batch = 1024;
        }
 out: