[PATCH 2/2] btrfs: Use list_for_each_entry_safe in free_reloc_roots

Nikolay Borisov
2020-02-21T13:11:28Z

The function always works on a local copy of the reloc root list, which
cannot be modified outside of it so using list_for_each_entry is fine.
Additionally the macro handles empty lists so drop list_empty checks of
callers. No semantic changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
fs/btrfs/relocation.c | 16 +++++-----------
1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index e5cb64409f7c..f13b79adf6b0 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -2523,13 +2523,10 @@ int prepare_to_merge(struct reloc_control *rc, int err)
static noinline_for_stack
void free_reloc_roots(struct list_head *list)
{
- struct btrfs_root *reloc_root;
+ struct btrfs_root *reloc_root, *tmp;

- while (!list_empty(list)) {
- reloc_root = list_entry(list->next, struct btrfs_root,
- root_list);
+ list_for_each_entry_safe(reloc_root, tmp, list, root_list)
__del_reloc_root(reloc_root);
- }
}

static noinline_for_stack
@@ -2588,15 +2585,13 @@ void merge_reloc_roots(struct reloc_control *rc)
out:
if (ret) {
btrfs_handle_fs_error(fs_info, ret, NULL);
- if (!list_empty(&reloc_roots))
- free_reloc_roots(&reloc_roots);
+ free_reloc_roots(&reloc_roots);

/* new reloc root may be added */
mutex_lock(&fs_info->reloc_mutex);
list_splice_init(&rc->reloc_roots, &reloc_roots);
mutex_unlock(&fs_info->reloc_mutex);
- if (!list_empty(&reloc_roots))
- free_reloc_roots(&reloc_roots);
+ free_reloc_roots(&reloc_roots);
}

BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
@@ -4689,8 +4684,7 @@ int btrfs_recover_relocation(struct btrfs_root *root)
out_free:
kfree(rc);
out:
- if (!list_empty(&reloc_roots))
- free_reloc_roots(&reloc_roots);
+ free_reloc_roots(&reloc_roots);

btrfs_free_path(path);

--
2.17.1