From 0bc19f9031e0c59770286f82b8561c1d35064a65 Mon Sep 17 00:00:00 2001
From: Zhao Lei <zhaolei@cn.fujitsu.com>
Date: Wed, 6 Jan 2016 18:56:36 +0800
Subject: [PATCH] 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>
---
 fs/btrfs/ctree.h       |  1 +
 fs/btrfs/extent-tree.c | 20 ++++++++++++++++++++
 fs/btrfs/inode.c       | 22 +---------------------
 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);