[PATCH 3.16 045/366] vfs: add the sb_start_intwrite_trylock() helper

[Ben Hutchings]

3.16.61-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Amir Goldstein <amir73il@xxxxxxxxx>

commit 0c8e3fe35db9b66ae0030849545030ec7c0fc45c upstream.

Needed by ext4 to test frozen fs before updating s_last_mounted.

Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 include/linux/fs.h | 5 +++++
 1 file changed, 5 insertions(+)

--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1389,6 +1389,11 @@ static inline void sb_start_intwrite(str
 	__sb_start_write(sb, SB_FREEZE_FS, true);
 }
 
+static inline int sb_start_intwrite_trylock(struct super_block *sb)
+{
+	return __sb_start_write(sb, SB_FREEZE_FS, false);
+}
+
 
 extern bool inode_owner_or_capable(const struct inode *inode);