f2fs: introduce zombie list for fast shrinking extent trees
This patch removes refcount, and instead, adds zombie_list to shrink directly
without radix tree traverse.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c
index b37184f..4dee2be 100644
--- a/fs/f2fs/extent_cache.c
+++ b/fs/f2fs/extent_cache.c
@@ -68,13 +68,13 @@
et->root = RB_ROOT;
et->cached_en = NULL;
rwlock_init(&et->lock);
- atomic_set(&et->refcount, 0);
+ INIT_LIST_HEAD(&et->list);
et->count = 0;
atomic_inc(&sbi->total_ext_tree);
} else {
atomic_dec(&sbi->total_zombie_tree);
+ list_del_init(&et->list);
}
- atomic_inc(&et->refcount);
up_write(&sbi->extent_tree_lock);
/* never died until evict_inode */
@@ -551,9 +551,9 @@
unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)
{
struct extent_tree *treevec[EXT_TREE_VEC_SIZE];
+ struct extent_tree *et, *next;
struct extent_node *en, *tmp;
unsigned long ino = F2FS_ROOT_INO(sbi);
- struct radix_tree_root *root = &sbi->extent_tree_root;
unsigned int found;
unsigned int node_cnt = 0, tree_cnt = 0;
int remained;
@@ -569,29 +569,20 @@
goto out;
/* 1. remove unreferenced extent tree */
- while ((found = radix_tree_gang_lookup(root,
- (void **)treevec, ino, EXT_TREE_VEC_SIZE))) {
- unsigned i;
+ list_for_each_entry_safe(et, next, &sbi->zombie_list, list) {
+ write_lock(&et->lock);
+ node_cnt += __free_extent_tree(sbi, et, true);
+ write_unlock(&et->lock);
- ino = treevec[found - 1]->ino + 1;
- for (i = 0; i < found; i++) {
- struct extent_tree *et = treevec[i];
+ list_del_init(&et->list);
+ radix_tree_delete(&sbi->extent_tree_root, et->ino);
+ kmem_cache_free(extent_tree_slab, et);
+ atomic_dec(&sbi->total_ext_tree);
+ atomic_dec(&sbi->total_zombie_tree);
+ tree_cnt++;
- if (!atomic_read(&et->refcount)) {
- write_lock(&et->lock);
- node_cnt += __free_extent_tree(sbi, et, true);
- write_unlock(&et->lock);
-
- radix_tree_delete(root, et->ino);
- kmem_cache_free(extent_tree_slab, et);
- atomic_dec(&sbi->total_ext_tree);
- atomic_dec(&sbi->total_zombie_tree);
- tree_cnt++;
-
- if (node_cnt + tree_cnt >= nr_shrink)
- goto unlock_out;
- }
- }
+ if (node_cnt + tree_cnt >= nr_shrink)
+ goto unlock_out;
}
up_write(&sbi->extent_tree_lock);
@@ -619,7 +610,7 @@
*/
ino = F2FS_ROOT_INO(sbi);
- while ((found = radix_tree_gang_lookup(root,
+ while ((found = radix_tree_gang_lookup(&sbi->extent_tree_root,
(void **)treevec, ino, EXT_TREE_VEC_SIZE))) {
unsigned i;
@@ -670,8 +661,10 @@
return;
if (inode->i_nlink && !is_bad_inode(inode) && et->count) {
- atomic_dec(&et->refcount);
+ down_write(&sbi->extent_tree_lock);
+ list_add_tail(&et->list, &sbi->zombie_list);
atomic_inc(&sbi->total_zombie_tree);
+ up_write(&sbi->extent_tree_lock);
return;
}
@@ -680,8 +673,7 @@
/* delete extent tree entry in radix tree */
down_write(&sbi->extent_tree_lock);
- atomic_dec(&et->refcount);
- f2fs_bug_on(sbi, atomic_read(&et->refcount) || et->count);
+ f2fs_bug_on(sbi, et->count);
radix_tree_delete(&sbi->extent_tree_root, inode->i_ino);
kmem_cache_free(extent_tree_slab, et);
atomic_dec(&sbi->total_ext_tree);
@@ -737,6 +729,7 @@
INIT_LIST_HEAD(&sbi->extent_list);
spin_lock_init(&sbi->extent_lock);
atomic_set(&sbi->total_ext_tree, 0);
+ INIT_LIST_HEAD(&sbi->zombie_list);
atomic_set(&sbi->total_zombie_tree, 0);
atomic_set(&sbi->total_ext_node, 0);
}