[34-longterm 138/260] ext4: Fix remaining racy updates of EXT4_I(inode)->i_flags

Paul Gortmaker
2011-01-02T07:49:50Z

From: Dmitry Monakhov <dmonakhov@openvz.org>

commit 84a8dce2710cc425089a2b92acc354d4fbb5788d upstream.

A few functions were still modifying i_flags in a racy manner.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
fs/ext4/inode.c | 40 +++++++++++++++++++++++-----------------
1 files changed, 23 insertions(+), 17 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 3fd683f..4eced51 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4932,20 +4932,26 @@ void ext4_set_inode_flags(struct inode *inode)
/* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
void ext4_get_inode_flags(struct ext4_inode_info *ei)
{
- unsigned int flags = ei->vfs_inode.i_flags;
-
- ei->i_flags &= ~(EXT4_SYNC_FL|EXT4_APPEND_FL|
- EXT4_IMMUTABLE_FL|EXT4_NOATIME_FL|EXT4_DIRSYNC_FL);
- if (flags & S_SYNC)
- ei->i_flags |= EXT4_SYNC_FL;
- if (flags & S_APPEND)
- ei->i_flags |= EXT4_APPEND_FL;
- if (flags & S_IMMUTABLE)
- ei->i_flags |= EXT4_IMMUTABLE_FL;
- if (flags & S_NOATIME)
- ei->i_flags |= EXT4_NOATIME_FL;
- if (flags & S_DIRSYNC)
- ei->i_flags |= EXT4_DIRSYNC_FL;
+ unsigned int vfs_fl;
+ unsigned long old_fl, new_fl;
+
+ do {
+ vfs_fl = ei->vfs_inode.i_flags;
+ old_fl = ei->i_flags;
+ new_fl = old_fl & ~(EXT4_SYNC_FL|EXT4_APPEND_FL|
+ EXT4_IMMUTABLE_FL|EXT4_NOATIME_FL|
+ EXT4_DIRSYNC_FL);
+ if (vfs_fl & S_SYNC)
+ new_fl |= EXT4_SYNC_FL;
+ if (vfs_fl & S_APPEND)
+ new_fl |= EXT4_APPEND_FL;
+ if (vfs_fl & S_IMMUTABLE)
+ new_fl |= EXT4_IMMUTABLE_FL;
+ if (vfs_fl & S_NOATIME)
+ new_fl |= EXT4_NOATIME_FL;
+ if (vfs_fl & S_DIRSYNC)
+ new_fl |= EXT4_DIRSYNC_FL;
+ } while (cmpxchg(&ei->i_flags, old_fl, new_fl) != old_fl);
}

static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,
@@ -5182,7 +5188,7 @@ static int ext4_inode_blocks_set(handle_t *handle,
*/
raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
raw_inode->i_blocks_high = 0;
- ei->i_flags &= ~EXT4_HUGE_FILE_FL;
+ ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
return 0;
}
if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE))
@@ -5195,9 +5201,9 @@ static int ext4_inode_blocks_set(handle_t *handle,
*/
raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
- ei->i_flags &= ~EXT4_HUGE_FILE_FL;
+ ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
} else {
- ei->i_flags |= EXT4_HUGE_FILE_FL;
+ ext4_set_inode_flag(inode, EXT4_INODE_HUGE_FILE);
/* i_block is stored in file system block size */
i_blocks = i_blocks >> (inode->i_blkbits - 9);
raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
--
1.7.3.3