[ 64/82] ext4: dont trash state flags in EXT4_IOC_SETFLAGS
From: Greg KH <gregkh@linuxfoundation.org>
Date: 2012-06-07 04:38:20
Also in:
lkml
3.4-stable review patch. If anyone has any objections, please let me know.
------------------
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 <redacted>
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@@ -38,7 +38,7 @@ 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))
@@ -115,8 +115,14 @@ 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);