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 <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index da27710..bc7684b 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -39,6 +39,13 @@
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 @@
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 @@
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 @@
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 @@
goto free_nm;
}
+ f2fs_join_shrinker(sbi);
+
/* if there are nt orphan nodes free them */
recover_orphan_inodes(sbi);
@@ -1310,7 +1328,10 @@
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 @@
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 @@
{
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();