From 2658e50de61429f57d9496bfe371f232e2d039a1 Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Fri, 19 Jun 2015 12:01:21 -0700 Subject: [PATCH] f2fs: introduce a shrinker for mounted fs This patch introduces a shrinker targeting to reduce memory footprint consumed by a number of in-memory f2fs data structures. In addition, it newly adds: - sbi->umount_mutex to avoid data races on shrinker and put_super - sbi->shruinker_run_no to not revisit objects Note that the basic implementation was copied from fs/ubifs/shrinker.c Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/Makefile | 1 + fs/f2fs/f2fs.h | 13 ++++++ fs/f2fs/shrinker.c | 104 +++++++++++++++++++++++++++++++++++++++++++++ fs/f2fs/super.c | 31 +++++++++++++- 4 files changed, 148 insertions(+), 1 deletion(-) create mode 100644 fs/f2fs/shrinker.c diff --git a/fs/f2fs/Makefile b/fs/f2fs/Makefile index 396be1a39e55..005251b8d459 100644 --- a/fs/f2fs/Makefile +++ b/fs/f2fs/Makefile @@ -2,6 +2,7 @@ obj-$(CONFIG_F2FS_FS) += f2fs.o f2fs-y := dir.o file.o inode.o namei.o hash.o super.o inline.o f2fs-y += checkpoint.o gc.o data.o node.o segment.o recovery.o +f2fs-y += shrinker.o f2fs-$(CONFIG_F2FS_STAT_FS) += debug.o f2fs-$(CONFIG_F2FS_FS_XATTR) += xattr.o f2fs-$(CONFIG_F2FS_FS_POSIX_ACL) += acl.o diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 3aaa4b99050a..e82af8c7ee8c 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -791,6 +791,11 @@ struct f2fs_sb_info { /* For sysfs suppport */ struct kobject s_kobj; struct completion s_kobj_unregister; + + /* For shrinker support */ + struct list_head s_list; + struct mutex umount_mutex; + unsigned int shrinker_run_no; }; /* @@ -1951,6 +1956,14 @@ bool f2fs_empty_inline_dir(struct inode *); int f2fs_read_inline_dir(struct file *, struct dir_context *, struct f2fs_str *); +/* + * shrinker.c + */ +unsigned long f2fs_shrink_count(struct shrinker *, struct shrink_control *); +unsigned long f2fs_shrink_scan(struct shrinker *, struct shrink_control *); +void f2fs_join_shrinker(struct f2fs_sb_info *); +void f2fs_leave_shrinker(struct f2fs_sb_info *); + /* * crypto support */ diff --git a/fs/f2fs/shrinker.c b/fs/f2fs/shrinker.c new file mode 100644 index 000000000000..16e9b43635c2 --- /dev/null +++ b/fs/f2fs/shrinker.c @@ -0,0 +1,104 @@ +/* + * f2fs shrinker support + * the basic infra was copied from fs/ubifs/shrinker.c + * + * Copyright (c) 2015 Motorola Mobility + * Copyright (c) 2015 Jaegeuk Kim + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include +#include + +#include "f2fs.h" + +static LIST_HEAD(f2fs_list); +static DEFINE_SPINLOCK(f2fs_list_lock); +static unsigned int shrinker_run_no; + +unsigned long f2fs_shrink_count(struct shrinker *shrink, + struct shrink_control *sc) +{ + struct f2fs_sb_info *sbi; + struct list_head *p; + unsigned long count = 0; + + spin_lock(&f2fs_list_lock); + p = f2fs_list.next; + while (p != &f2fs_list) { + sbi = list_entry(p, struct f2fs_sb_info, s_list); + + /* stop f2fs_put_super */ + if (!mutex_trylock(&sbi->umount_mutex)) { + p = p->next; + continue; + } + spin_unlock(&f2fs_list_lock); + + /* TODO: count # of objects */ + + spin_lock(&f2fs_list_lock); + p = p->next; + mutex_unlock(&sbi->umount_mutex); + } + spin_unlock(&f2fs_list_lock); + return count; +} + +unsigned long f2fs_shrink_scan(struct shrinker *shrink, + struct shrink_control *sc) +{ + unsigned long nr = sc->nr_to_scan; + struct f2fs_sb_info *sbi; + struct list_head *p; + unsigned int run_no; + unsigned long freed = 0; + + spin_lock(&f2fs_list_lock); + do { + run_no = ++shrinker_run_no; + } while (run_no == 0); + p = f2fs_list.next; + while (p != &f2fs_list) { + sbi = list_entry(p, struct f2fs_sb_info, s_list); + + if (sbi->shrinker_run_no == run_no) + break; + + /* stop f2fs_put_super */ + if (!mutex_trylock(&sbi->umount_mutex)) { + p = p->next; + continue; + } + spin_unlock(&f2fs_list_lock); + + sbi->shrinker_run_no = run_no; + + /* TODO: shrink caches */ + + spin_lock(&f2fs_list_lock); + p = p->next; + list_move_tail(&sbi->s_list, &f2fs_list); + mutex_unlock(&sbi->umount_mutex); + if (freed >= nr) + break; + } + spin_unlock(&f2fs_list_lock); + return freed; +} + +void f2fs_join_shrinker(struct f2fs_sb_info *sbi) +{ + spin_lock(&f2fs_list_lock); + list_add_tail(&sbi->s_list, &f2fs_list); + spin_unlock(&f2fs_list_lock); +} + +void f2fs_leave_shrinker(struct f2fs_sb_info *sbi) +{ + spin_lock(&f2fs_list_lock); + list_del(&sbi->s_list); + spin_unlock(&f2fs_list_lock); +} diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index da277100dc90..bc7684b6d57a 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -39,6 +39,13 @@ static struct proc_dir_entry *f2fs_proc_root; static struct kmem_cache *f2fs_inode_cachep; static struct kset *f2fs_kset; +/* f2fs-wide shrinker description */ +static struct shrinker f2fs_shrinker_info = { + .scan_objects = f2fs_shrink_scan, + .count_objects = f2fs_shrink_count, + .seeks = DEFAULT_SEEKS, +}; + enum { Opt_gc_background, Opt_disable_roll_forward, @@ -500,6 +507,9 @@ static void f2fs_put_super(struct super_block *sb) stop_gc_thread(sbi); + /* prevent remaining shrinker jobs */ + mutex_lock(&sbi->umount_mutex); + /* * We don't need to do checkpoint when superblock is clean. * But, the previous checkpoint was not done by umount, it needs to do @@ -523,6 +533,9 @@ static void f2fs_put_super(struct super_block *sb) release_dirty_inode(sbi); release_discard_addrs(sbi); + f2fs_leave_shrinker(sbi); + mutex_unlock(&sbi->umount_mutex); + iput(sbi->node_inode); iput(sbi->meta_inode); @@ -972,6 +985,9 @@ static void init_sb_info(struct f2fs_sb_info *sbi) sbi->dir_level = DEF_DIR_LEVEL; clear_sbi_flag(sbi, SBI_NEED_FSCK); + + INIT_LIST_HEAD(&sbi->s_list); + mutex_init(&sbi->umount_mutex); } /* @@ -1214,6 +1230,8 @@ try_onemore: goto free_nm; } + f2fs_join_shrinker(sbi); + /* if there are nt orphan nodes free them */ recover_orphan_inodes(sbi); @@ -1310,7 +1328,10 @@ free_root_inode: dput(sb->s_root); sb->s_root = NULL; free_node_inode: + mutex_lock(&sbi->umount_mutex); + f2fs_leave_shrinker(sbi); iput(sbi->node_inode); + mutex_unlock(&sbi->umount_mutex); free_nm: destroy_node_manager(sbi); free_sm: @@ -1406,13 +1427,20 @@ static int __init init_f2fs_fs(void) err = f2fs_init_crypto(); if (err) goto free_kset; - err = register_filesystem(&f2fs_fs_type); + + err = register_shrinker(&f2fs_shrinker_info); if (err) goto free_crypto; + + err = register_filesystem(&f2fs_fs_type); + if (err) + goto free_shrinker; f2fs_create_root_stats(); f2fs_proc_root = proc_mkdir("fs/f2fs", NULL); return 0; +free_shrinker: + unregister_shrinker(&f2fs_shrinker_info); free_crypto: f2fs_exit_crypto(); free_kset: @@ -1435,6 +1463,7 @@ static void __exit exit_f2fs_fs(void) { remove_proc_entry("fs/f2fs", NULL); f2fs_destroy_root_stats(); + unregister_shrinker(&f2fs_shrinker_info); unregister_filesystem(&f2fs_fs_type); f2fs_exit_crypto(); destroy_extent_cache(); -- 2.20.1