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, 3 insertions, 0 deletions

diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
index 89d0422a91a8..84191307a670 100644
--- a/fs/f2fs/xattr.c
+++ b/fs/f2fs/xattr.c
@@ -590,7 +590,10 @@ int f2fs_setxattr(struct inode *inode, int name_index, const char *name,
         f2fs_balance_fs(sbi);
 
         f2fs_lock_op(sbi);
+        /* protect xattr_ver */
+        down_write(&F2FS_I(inode)->i_sem);
         err = __f2fs_setxattr(inode, name_index, name, value, value_len, ipage);
+        up_write(&F2FS_I(inode)->i_sem);
         f2fs_unlock_op(sbi);
 
         return err;