btrfs: merge functions for wait snapshot creation

wait_for_snapshot_creation() is in same group with oher two:
 btrfs_start_write_no_snapshoting()
 btrfs_end_write_no_snapshoting()

Rename wait_for_snapshot_creation() and move it into same place
with other two.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

3 files changed, 22 insertions, 21 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index e9c2f8895eab..a9496644f47d 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3641,6 +3641,7 @@ int btrfs_delayed_refs_qgroup_accounting(struct btrfs_trans_handle *trans,
 int __get_raid_index(u64 flags);
 int btrfs_start_write_no_snapshoting(struct btrfs_root *root);
 void btrfs_end_write_no_snapshoting(struct btrfs_root *root);
+void btrfs_wait_for_snapshot_creation(struct btrfs_root *root);
 void check_system_chunk(struct btrfs_trans_handle *trans,
                         struct btrfs_root *root,
                         const u64 type);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index abcffa4b8231..8e8079808728 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -10817,3 +10817,23 @@ int btrfs_start_write_no_snapshoting(struct btrfs_root *root)
         }
         return 1;
 }
+
+static int wait_snapshoting_atomic_t(atomic_t *a)
+{
+        schedule();
+        return 0;
+}
+
+void btrfs_wait_for_snapshot_creation(struct btrfs_root *root)
+{
+        while (true) {
+                int ret;
+
+                ret = btrfs_start_write_no_snapshoting(root);
+                if (ret)
+                        break;
+                wait_on_atomic_t(&root->will_be_snapshoted,
+                                 wait_snapshoting_atomic_t,
+                                 TASK_UNINTERRUPTIBLE);
+        }
+}
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 8ad9e2200442..b8bb7591ff9f 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4871,26 +4871,6 @@ next:
         return err;
 }
 
-static int wait_snapshoting_atomic_t(atomic_t *a)
-{
-        schedule();
-        return 0;
-}
-
-static void wait_for_snapshot_creation(struct btrfs_root *root)
-{
-        while (true) {
-                int ret;
-
-                ret = btrfs_start_write_no_snapshoting(root);
-                if (ret)
-                        break;
-                wait_on_atomic_t(&root->will_be_snapshoted,
-                                 wait_snapshoting_atomic_t,
-                                 TASK_UNINTERRUPTIBLE);
-        }
-}
-
 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
 {
         struct btrfs_root *root = BTRFS_I(inode)->root;
@@ -4922,7 +4902,7 @@ static int btrfs_setsize(struct inode *inode, struct iattr *attr)
                  * truncation, it must capture all writes that happened before
                  * this truncation.
                  */
-                wait_for_snapshot_creation(root);
+                btrfs_wait_for_snapshot_creation(root);
                 ret = btrfs_cont_expand(inode, oldsize, newsize);
                 if (ret) {
                         btrfs_end_write_no_snapshoting(root);