ext4: Use bitops to read/modify i_flags in struct ext4_inode_info

At several places we modify EXT4_I(inode)->i_flags without holding
i_mutex (ext4_do_update_inode, ...). These modifications are racy and
we can lose updates to i_flags. So convert handling of i_flags to use
bitops which are atomic.

https://bugzilla.kernel.org/show_bug.cgi?id=15792

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index 6a2b8bcff641..ea5e6cb7e2a5 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -110,7 +110,7 @@ static int ext4_readdir(struct file *filp,
 
         if (EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
                                     EXT4_FEATURE_COMPAT_DIR_INDEX) &&
-            ((EXT4_I(inode)->i_flags & EXT4_INDEX_FL) ||
+            ((ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) ||
              ((inode->i_size >> sb->s_blocksize_bits) == 1))) {
                 err = ext4_dx_readdir(filp, dirent, filldir);
                 if (err != ERR_BAD_DX_DIR) {
@@ -121,7 +121,7 @@ static int ext4_readdir(struct file *filp,
                  * We don't set the inode dirty flag since it's not
                  * critical that it get flushed back to the disk.
                  */
-                EXT4_I(filp->f_path.dentry->d_inode)->i_flags &= ~EXT4_INDEX_FL;
+                ext4_clear_inode_flag(filp->f_path.dentry->d_inode, EXT4_INODE_INDEX);
         }
         stored = 0;
         offset = filp->f_pos & (sb->s_blocksize - 1);