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>
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index bff77b0..7b4bf8f 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -656,7 +656,7 @@
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 @@
{
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 @@
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 @@
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 @@
}
} 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;