add-the-sb_start_intwrite_trylock-helper

   1 vfs: add the sb_start_intwrite_trylock() helper
   2
   3 From: Amir Goldstein <amir73il@gmail.com>
   4
   5 Needed by ext4 to test frozen fs before updating s_last_mounted.
   6
   7 Signed-off-by: Amir Goldstein <amir73il@gmail.com>
   8 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
   9 Reviewed-by: Jan Kara <jack@suse.cz>
  10 ---
  11  include/linux/fs.h | 5 +++++
  12  1 file changed, 5 insertions(+)
  13
  14 diff --git a/include/linux/fs.h b/include/linux/fs.h
  15 index 760d8da1b6c7..cac41f1bad05 100644
  16 --- a/include/linux/fs.h
  17 +++ b/include/linux/fs.h
  18 @@ -1597,6 +1597,11 @@ static inline void sb_start_intwrite(struct super_block *sb)
  19         __sb_start_write(sb, SB_FREEZE_FS, true);
  20  }
  21
  22 +static inline int sb_start_intwrite_trylock(struct super_block *sb)
  23 +{
  24 +       return __sb_start_write(sb, SB_FREEZE_FS, false);
  25 +}
  26 +
  27
  28  extern bool inode_owner_or_capable(const struct inode *inode);
  29
  30 --
  31 2.7.4
  32
  33