f2fs: introduce fi->i_sem to protect fi's info

This patch introduces fi->i_sem to protect fi's info that includes xattr_ver,
pino, i_nlink.
This enables to remove i_mutex during f2fs_sync_file, resulting in performance
improvement when a number of fsync calls are triggered from many concurrent
threads.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 05c652493f04..469779ab1d77 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -210,6 +210,7 @@ struct f2fs_inode_info {
 
         /* Use below internally in f2fs*/
         unsigned long flags;            /* use to pass per-file flags */
+        struct rw_semaphore i_sem;      /* protect fi info */
         atomic_t dirty_dents;           /* # of dirty dentry pages */
         f2fs_hash_t chash;              /* hash value of given file name */
         unsigned int clevel;            /* maximum level of given file name */