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, 5 insertions, 5 deletions

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index bff77b04f0d1..7b4bf8feae4e 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -656,7 +656,7 @@ int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n", 
                        start_hash, start_minor_hash));
         dir = dir_file->f_path.dentry->d_inode;
-        if (!(EXT4_I(dir)->i_flags & EXT4_INDEX_FL)) {
+        if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) {
                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
                 if (hinfo.hash_version <= DX_HASH_TEA)
                         hinfo.hash_version +=
@@ -801,7 +801,7 @@ static void ext4_update_dx_flag(struct inode *inode)
 {
         if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
                                      EXT4_FEATURE_COMPAT_DIR_INDEX))
-                EXT4_I(inode)->i_flags &= ~EXT4_INDEX_FL;
+                ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
 }
 
 /*
@@ -1416,7 +1416,7 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
                 brelse(bh);
                 return retval;
         }
-        EXT4_I(dir)->i_flags |= EXT4_INDEX_FL;
+        ext4_set_inode_flag(dir, EXT4_INODE_INDEX);
         data1 = bh2->b_data;
 
         memcpy (data1, de, len);
@@ -1489,7 +1489,7 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
                 retval = ext4_dx_add_entry(handle, dentry, inode);
                 if (!retval || (retval != ERR_BAD_DX_DIR))
                         return retval;
-                EXT4_I(dir)->i_flags &= ~EXT4_INDEX_FL;
+                ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
                 dx_fallback++;
                 ext4_mark_inode_dirty(handle, dir);
         }
@@ -2294,7 +2294,7 @@ retry:
                 }
         } else {
                 /* clear the extent format for fast symlink */
-                EXT4_I(inode)->i_flags &= ~EXT4_EXTENTS_FL;
+                ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
                 inode->i_op = &ext4_fast_symlink_inode_operations;
                 memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
                 inode->i_size = l-1;