From 1ab6c4997e04a00c50c6d786c2f046adc0d1f5de Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Wed, 28 Aug 2013 10:18:09 +1000 Subject: fs: convert fs shrinkers to new scan/count API MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Convert the filesystem shrinkers to use the new API, and standardise some of the behaviours of the shrinkers at the same time. For example, nr_to_scan means the number of objects to scan, not the number of objects to free. I refactored the CIFS idmap shrinker a little - it really needs to be broken up into a shrinker per tree and keep an item count with the tree root so that we don't need to walk the tree every time the shrinker needs to count the number of objects in the tree (i.e. all the time under memory pressure). [glommer@openvz.org: fixes for ext4, ubifs, nfs, cifs and glock. Fixes are needed mainly due to new code merged in the tree] [assorted fixes folded in] Signed-off-by: Dave Chinner Signed-off-by: Glauber Costa Acked-by: Mel Gorman Acked-by: Artem Bityutskiy Acked-by: Jan Kara Acked-by: Steven Whitehouse Cc: Adrian Hunter Cc: "Theodore Ts'o" Cc: Adrian Hunter Cc: Al Viro Cc: Artem Bityutskiy Cc: Arve Hjønnevåg Cc: Carlos Maiolino Cc: Christoph Hellwig Cc: Chuck Lever Cc: Daniel Vetter Cc: David Rientjes Cc: Gleb Natapov Cc: Greg Thelen Cc: J. Bruce Fields Cc: Jan Kara Cc: Jerome Glisse Cc: John Stultz Cc: KAMEZAWA Hiroyuki Cc: Kent Overstreet Cc: Kirill A. Shutemov Cc: Marcelo Tosatti Cc: Mel Gorman Cc: Steven Whitehouse Cc: Thomas Hellstrom Cc: Trond Myklebust Signed-off-by: Andrew Morton Signed-off-by: Al Viro --- fs/ext4/extents_status.c | 33 ++++++++++++++++++++++++--------- 1 file changed, 24 insertions(+), 9 deletions(-) (limited to 'fs/ext4') diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c index 2d1bdbe78c04..3981ff783950 100644 --- a/fs/ext4/extents_status.c +++ b/fs/ext4/extents_status.c @@ -931,13 +931,15 @@ static int __ext4_es_shrink(struct ext4_sb_info *sbi, int nr_to_scan, struct ext4_inode_info *ei; struct list_head *cur, *tmp; LIST_HEAD(skipped); - int ret, nr_shrunk = 0; + int nr_shrunk = 0; int retried = 0, skip_precached = 1, nr_skipped = 0; spin_lock(&sbi->s_es_lru_lock); retry: list_for_each_safe(cur, tmp, &sbi->s_es_lru) { + int shrunk; + /* * If we have already reclaimed all extents from extent * status tree, just stop the loop immediately. @@ -964,13 +966,13 @@ retry: continue; write_lock(&ei->i_es_lock); - ret = __es_try_to_reclaim_extents(ei, nr_to_scan); + shrunk = __es_try_to_reclaim_extents(ei, nr_to_scan); if (ei->i_es_lru_nr == 0) list_del_init(&ei->i_es_lru); write_unlock(&ei->i_es_lock); - nr_shrunk += ret; - nr_to_scan -= ret; + nr_shrunk += shrunk; + nr_to_scan -= shrunk; if (nr_to_scan == 0) break; } @@ -1007,7 +1009,20 @@ retry: return nr_shrunk; } -static int ext4_es_shrink(struct shrinker *shrink, struct shrink_control *sc) +static unsigned long ext4_es_count(struct shrinker *shrink, + struct shrink_control *sc) +{ + unsigned long nr; + struct ext4_sb_info *sbi; + + sbi = container_of(shrink, struct ext4_sb_info, s_es_shrinker); + nr = percpu_counter_read_positive(&sbi->s_extent_cache_cnt); + trace_ext4_es_shrink_enter(sbi->s_sb, sc->nr_to_scan, nr); + return nr; +} + +static unsigned long ext4_es_scan(struct shrinker *shrink, + struct shrink_control *sc) { struct ext4_sb_info *sbi = container_of(shrink, struct ext4_sb_info, s_es_shrinker); @@ -1022,9 +1037,8 @@ static int ext4_es_shrink(struct shrinker *shrink, struct shrink_control *sc) nr_shrunk = __ext4_es_shrink(sbi, nr_to_scan, NULL); - ret = percpu_counter_read_positive(&sbi->s_extent_cache_cnt); trace_ext4_es_shrink_exit(sbi->s_sb, nr_shrunk, ret); - return ret; + return nr_shrunk; } void ext4_es_register_shrinker(struct ext4_sb_info *sbi) @@ -1032,7 +1046,8 @@ void ext4_es_register_shrinker(struct ext4_sb_info *sbi) INIT_LIST_HEAD(&sbi->s_es_lru); spin_lock_init(&sbi->s_es_lru_lock); sbi->s_es_last_sorted = 0; - sbi->s_es_shrinker.shrink = ext4_es_shrink; + sbi->s_es_shrinker.scan_objects = ext4_es_scan; + sbi->s_es_shrinker.count_objects = ext4_es_count; sbi->s_es_shrinker.seeks = DEFAULT_SEEKS; register_shrinker(&sbi->s_es_shrinker); } @@ -1076,7 +1091,7 @@ static int __es_try_to_reclaim_extents(struct ext4_inode_info *ei, struct ext4_es_tree *tree = &ei->i_es_tree; struct rb_node *node; struct extent_status *es; - int nr_shrunk = 0; + unsigned long nr_shrunk = 0; static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); -- cgit v1.2.2