Btrfs: remove unnecessary lock in may_commit_transaction()

The reason is:
- The per-cpu counter has its own lock to protect itself.
- Here we needn't get a exact value.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 6b821c64b37b715f2ad1d6e4e23ae0e1cddf04ad..5608b4f8a27e536b2993d07e1b7e177fe8e39b47 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4112,13 +4112,9 @@ static int may_commit_transaction(struct btrfs_root *root,
                goto commit;
 
        /* See if there is enough pinned space to make this reservation */
-       spin_lock(&space_info->lock);
        if (percpu_counter_compare(&space_info->total_bytes_pinned,
-                                  bytes) >= 0) {
-               spin_unlock(&space_info->lock);
+                                  bytes) >= 0)
                goto commit;
-       }
-       spin_unlock(&space_info->lock);
 
        /*
         * See if there is some space in the delayed insertion reservation for
@@ -4127,16 +4123,13 @@ static int may_commit_transaction(struct btrfs_root *root,
        if (space_info != delayed_rsv->space_info)
                return -ENOSPC;
 
-       spin_lock(&space_info->lock);
        spin_lock(&delayed_rsv->lock);
        if (percpu_counter_compare(&space_info->total_bytes_pinned,
                                   bytes - delayed_rsv->size) >= 0) {
                spin_unlock(&delayed_rsv->lock);
-               spin_unlock(&space_info->lock);
                return -ENOSPC;
        }
        spin_unlock(&delayed_rsv->lock);
-       spin_unlock(&space_info->lock);
 
 commit:
        trans = btrfs_join_transaction(root);