From 0a234c6dcb79a270803f5c9773ed650b78730962 Mon Sep 17 00:00:00 2001
From: Dave Chinner
Date: Wed, 28 Aug 2013 10:17:57 +1000
Subject: shrinker: convert superblock shrinkers to new API

Convert superblock shrinker to use the new count/scan API, and propagate
the API changes through to the filesystem callouts.  The filesystem
callouts already use a count/scan API, so it's just changing counters to
longs to match the VM API.

This requires the dentry and inode shrinker callouts to be converted to
the count/scan API.  This is mainly a mechanical change.

[glommer@openvz.org: use mult_frac for fractional proportions, build fixes]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/dcache.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

(limited to 'fs/dcache.c')

diff --git a/fs/dcache.c b/fs/dcache.c
index 509b49410943..77d466b13fef 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -913,11 +913,12 @@ static void shrink_dentry_list(struct list_head *list)
  * This function may fail to free any resources if all the dentries are in
  * use.
  */
-void prune_dcache_sb(struct super_block *sb, int count)
+long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan)
 {
 	struct dentry *dentry;
 	LIST_HEAD(referenced);
 	LIST_HEAD(tmp);
+	long freed = 0;
 
 relock:
 	spin_lock(&sb->s_dentry_lru_lock);
@@ -942,7 +943,8 @@ relock:
 			this_cpu_dec(nr_dentry_unused);
 			sb->s_nr_dentry_unused--;
 			spin_unlock(&dentry->d_lock);
-			if (!--count)
+			freed++;
+			if (!--nr_to_scan)
 				break;
 		}
 		cond_resched_lock(&sb->s_dentry_lru_lock);
@@ -952,6 +954,7 @@ relock:
 	spin_unlock(&sb->s_dentry_lru_lock);
 
 	shrink_dentry_list(&tmp);
+	return freed;
 }
 
 /*
-- 
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