f2fs: use atomic type for node count in extent tree

1. rename field in struct extent_tree from count to node_cnt for
   readability.
2. alter to use atomic type for node_cnt.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c
index 4dee2be9a648ca75e2c5f0b6376f528fcd932737..9febbc622bf53103bca9eff0fe27d21aa7b26ed3 100644 (file)
--- a/fs/f2fs/extent_cache.c
+++ b/fs/f2fs/extent_cache.c
@@ -36,7 +36,7 @@ static struct extent_node *__attach_extent_node(struct f2fs_sb_info *sbi,
 
        rb_link_node(&en->rb_node, parent, p);
        rb_insert_color(&en->rb_node, &et->root);
-       et->count++;
+       atomic_inc(&et->node_cnt);
        atomic_inc(&sbi->total_ext_node);
        return en;
 }
@@ -45,7 +45,7 @@ static void __detach_extent_node(struct f2fs_sb_info *sbi,
                                struct extent_tree *et, struct extent_node *en)
 {
        rb_erase(&en->rb_node, &et->root);
-       et->count--;
+       atomic_dec(&et->node_cnt);
        atomic_dec(&sbi->total_ext_node);
 
        if (et->cached_en == en)
@@ -69,7 +69,7 @@ static struct extent_tree *__grab_extent_tree(struct inode *inode)
                et->cached_en = NULL;
                rwlock_init(&et->lock);
                INIT_LIST_HEAD(&et->list);
-               et->count = 0;
+               atomic_set(&et->node_cnt, 0);
                atomic_inc(&sbi->total_ext_tree);
        } else {
                atomic_dec(&sbi->total_zombie_tree);
@@ -133,7 +133,7 @@ static unsigned int __free_extent_tree(struct f2fs_sb_info *sbi,
 {
        struct rb_node *node, *next;
        struct extent_node *en;
-       unsigned int count = et->count;
+       unsigned int count = atomic_read(&et->node_cnt);
 
        node = rb_first(&et->root);
        while (node) {
@@ -154,7 +154,7 @@ static unsigned int __free_extent_tree(struct f2fs_sb_info *sbi,
                node = next;
        }
 
-       return count - et->count;
+       return count - atomic_read(&et->node_cnt);
 }
 
 static void __drop_largest_extent(struct inode *inode,
@@ -192,7 +192,7 @@ bool f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext)
                le32_to_cpu(i_ext->blk), le32_to_cpu(i_ext->len));
 
        write_lock(&et->lock);
-       if (et->count)
+       if (atomic_read(&et->node_cnt))
                goto out;
 
        en = __init_extent_tree(sbi, et, &ei);
@@ -660,7 +660,8 @@ void f2fs_destroy_extent_tree(struct inode *inode)
        if (!et)
                return;
 
-       if (inode->i_nlink && !is_bad_inode(inode) && et->count) {
+       if (inode->i_nlink && !is_bad_inode(inode) &&
+                                       atomic_read(&et->node_cnt)) {
                down_write(&sbi->extent_tree_lock);
                list_add_tail(&et->list, &sbi->zombie_list);
                atomic_inc(&sbi->total_zombie_tree);
@@ -673,7 +674,7 @@ void f2fs_destroy_extent_tree(struct inode *inode)
 
        /* delete extent tree entry in radix tree */
        down_write(&sbi->extent_tree_lock);
-       f2fs_bug_on(sbi, et->count);
+       f2fs_bug_on(sbi, atomic_read(&et->node_cnt));
        radix_tree_delete(&sbi->extent_tree_root, inode->i_ino);
        kmem_cache_free(extent_tree_slab, et);
        atomic_dec(&sbi->total_ext_tree);

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 412865482a0bcff1d35ff67a26371e55e99beb6f..ae0007df6c2cdad384505ca57c65beb6712b87b2 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -361,7 +361,7 @@ struct extent_tree {
        struct extent_info largest;     /* largested extent info */
        struct list_head list;          /* to be used by sbi->zombie_list */
        rwlock_t lock;                  /* protect extent info rb-tree */
-       unsigned int count;             /* # of extent node in rb-tree*/
+       atomic_t node_cnt;              /* # of extent node in rb-tree*/
 };
 
 /*