From 0a234c6dcb79a270803f5c9773ed650b78730962 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Wed, 28 Aug 2013 10:17:57 +1000 Subject: [PATCH] shrinker: convert superblock shrinkers to new API MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Glauber Costa Acked-by: Mel Gorman 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/dcache.c | 7 ++-- fs/inode.c | 7 ++-- fs/internal.h | 2 ++ fs/super.c | 80 +++++++++++++++++++++++++++------------------ fs/xfs/xfs_icache.c | 4 +-- fs/xfs/xfs_icache.h | 2 +- fs/xfs/xfs_super.c | 8 ++--- include/linux/fs.h | 8 ++--- 8 files changed, 70 insertions(+), 48 deletions(-) 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; } /* diff --git a/fs/inode.c b/fs/inode.c index 2a3c37ea823d..021d64768a55 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -706,10 +706,11 @@ static int can_unuse(struct inode *inode) * LRU does not have strict ordering. Hence we don't want to reclaim inodes * with this flag set because they are the inodes that are out of order. */ -void prune_icache_sb(struct super_block *sb, int nr_to_scan) +long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan) { LIST_HEAD(freeable); - int nr_scanned; + long nr_scanned; + long freed = 0; unsigned long reap = 0; spin_lock(&sb->s_inode_lru_lock); @@ -779,6 +780,7 @@ void prune_icache_sb(struct super_block *sb, int nr_to_scan) list_move(&inode->i_lru, &freeable); sb->s_nr_inodes_unused--; this_cpu_dec(nr_unused); + freed++; } if (current_is_kswapd()) __count_vm_events(KSWAPD_INODESTEAL, reap); @@ -789,6 +791,7 @@ void prune_icache_sb(struct super_block *sb, int nr_to_scan) current->reclaim_state->reclaimed_slab += reap; dispose_list(&freeable); + return freed; } static void __wait_on_freeing_inode(struct inode *inode); diff --git a/fs/internal.h b/fs/internal.h index b6495659d6e8..cb83a3417a68 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -114,6 +114,7 @@ extern int open_check_o_direct(struct file *f); * inode.c */ extern spinlock_t inode_sb_list_lock; +extern long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan); extern void inode_add_lru(struct inode *inode); /* @@ -130,6 +131,7 @@ extern int invalidate_inodes(struct super_block *, bool); */ extern struct dentry *__d_alloc(struct super_block *, const struct qstr *); extern int d_set_mounted(struct dentry *dentry); +extern long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan); /* * read_write.c diff --git a/fs/super.c b/fs/super.c index 3c5318694ccd..8aa2660642b9 100644 --- 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: diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c index 16219b9c6790..73b62a24ceac 100644 --- a/fs/xfs/xfs_icache.c +++ b/fs/xfs/xfs_icache.c @@ -1167,7 +1167,7 @@ xfs_reclaim_inodes( * them to be cleaned, which we hope will not be very long due to the * background walker having already kicked the IO off on those dirty inodes. */ -void +long xfs_reclaim_inodes_nr( struct xfs_mount *mp, int nr_to_scan) @@ -1176,7 +1176,7 @@ xfs_reclaim_inodes_nr( xfs_reclaim_work_queue(mp); xfs_ail_push_all(mp->m_ail); - xfs_reclaim_inodes_ag(mp, SYNC_TRYLOCK | SYNC_WAIT, &nr_to_scan); + return xfs_reclaim_inodes_ag(mp, SYNC_TRYLOCK | SYNC_WAIT, &nr_to_scan); } /* diff --git a/fs/xfs/xfs_icache.h b/fs/xfs/xfs_icache.h index 8a89f7d791bd..456f0144e1b6 100644 --- a/fs/xfs/xfs_icache.h +++ b/fs/xfs/xfs_icache.h @@ -46,7 +46,7 @@ void xfs_reclaim_worker(struct work_struct *work); int xfs_reclaim_inodes(struct xfs_mount *mp, int mode); int xfs_reclaim_inodes_count(struct xfs_mount *mp); -void xfs_reclaim_inodes_nr(struct xfs_mount *mp, int nr_to_scan); +long xfs_reclaim_inodes_nr(struct xfs_mount *mp, int nr_to_scan); void xfs_inode_set_reclaim_tag(struct xfs_inode *ip); diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index 979a77d4b87d..71d7aaebb912 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -1535,19 +1535,19 @@ xfs_fs_mount( return mount_bdev(fs_type, flags, dev_name, data, xfs_fs_fill_super); } -static int +static long xfs_fs_nr_cached_objects( struct super_block *sb) { return xfs_reclaim_inodes_count(XFS_M(sb)); } -static void +static long xfs_fs_free_cached_objects( struct super_block *sb, - int nr_to_scan) + long nr_to_scan) { - xfs_reclaim_inodes_nr(XFS_M(sb), nr_to_scan); + return xfs_reclaim_inodes_nr(XFS_M(sb), nr_to_scan); } static const struct super_operations xfs_super_operations = { diff --git a/include/linux/fs.h b/include/linux/fs.h index 14a90f6886fa..0ae0bc3c1fde 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1335,10 +1335,6 @@ struct super_block { struct workqueue_struct *s_dio_done_wq; }; -/* superblock cache pruning functions */ -extern void prune_icache_sb(struct super_block *sb, int nr_to_scan); -extern void prune_dcache_sb(struct super_block *sb, int nr_to_scan); - extern struct timespec current_fs_time(struct super_block *sb); /* @@ -1631,8 +1627,8 @@ struct super_operations { ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t); #endif int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t); - int (*nr_cached_objects)(struct super_block *); - void (*free_cached_objects)(struct super_block *, int); + long (*nr_cached_objects)(struct super_block *); + long (*free_cached_objects)(struct super_block *, long); }; /* -- 2.20.1