[ 42/47] ext4: dont trash state flags in EXT4_IOC_SETFLAGS

Greg KH
2012-06-07T04:27:36Z

From: Theodore Ts'o <tytso@mit.edu>

commit 79906964a187c405db72a3abc60eb9b50d804fbc upstream.

In commit 353eb83c we removed i_state_flags with 64-bit longs, But
when handling the EXT4_IOC_SETFLAGS ioctl, we replace i_flags
directly, which trashes the state flags which are stored in the high
32-bits of i_flags on 64-bit platforms. So use the the
ext4_{set,clear}_inode_flags() functions which use atomic bit
manipulation functions instead.

Reported-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/ext4/ioctl.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -35,7 +35,7 @@ long ext4_ioctl(struct file *filp, unsig
handle_t *handle = NULL;
int err, migrate = 0;
struct ext4_iloc iloc;
- unsigned int oldflags;
+ unsigned int oldflags, mask, i;
unsigned int jflag;

if (!inode_owner_or_capable(inode))
@@ -112,8 +112,14 @@ long ext4_ioctl(struct file *filp, unsig
if (err)
goto flags_err;

- flags = flags & EXT4_FL_USER_MODIFIABLE;
- flags |= oldflags & ~EXT4_FL_USER_MODIFIABLE;
+ for (i = 0, mask = 1; i < 32; i++, mask <<= 1) {
+ if (!(mask & EXT4_FL_USER_MODIFIABLE))
+ continue;
+ if (mask & flags)
+ ext4_set_inode_flag(inode, i);
+ else
+ ext4_clear_inode_flag(inode, i);
+ }
ei->i_flags = flags;

ext4_set_inode_flags(inode);