Re: [PATCH 5/8] xfs: Protect xfs_file_aio_write() & xfs_setattr_size() with sb_start_write - sb_end_write

Eric Sandeen
2012-02-04T04:30:07Z

On 1/20/12 2:34 PM, Jan Kara wrote:
> Replace racy xfs_wait_for_freeze() check in xfs_file_aio_write() with
> a reliable sb_start_write() - sb_end_write() locking.

Here's what I'm running with now. With this and my modified
patch6, I can pass xfstests 068 on xfs.

-Eric

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 7e5bc87..f1cacdc 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -874,11 +874,11 @@ xfs_file_aio_write(
if (ocount == 0)
return 0;

- xfs_wait_for_freeze(ip->i_mount, SB_FREEZE_WRITE);
-
if (XFS_FORCED_SHUTDOWN(ip->i_mount))
return -EIO;

+ sb_start_write(inode->i_sb, SB_FREEZE_WRITE);
+
if (unlikely(file->f_flags & O_DIRECT))
ret = xfs_file_dio_aio_write(iocb, iovp, nr_segs, pos, ocount);
else
@@ -895,6 +895,7 @@ xfs_file_aio_write(
if (err < 0)
ret = err;
}
+ sb_end_write(inode->i_sb, SB_FREEZE_WRITE);

return ret;
}
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index ab30253..7f3fa17 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -773,6 +773,7 @@ xfs_setattr_size(
ATTR_MTIME_SET|ATTR_KILL_SUID|ATTR_KILL_SGID|
ATTR_KILL_PRIV|ATTR_TIMES_SET)) == 0);

+ sb_start_write(inode->i_sb, SB_FREEZE_WRITE);
lock_flags = XFS_ILOCK_EXCL;
if (!(flags & XFS_ATTR_NOLOCK))
lock_flags |= XFS_IOLOCK_EXCL;
@@ -792,6 +793,7 @@ xfs_setattr_size(
* Use the regular setattr path to update the timestamps.
*/
xfs_iunlock(ip, lock_flags);
+ sb_end_write(inode->i_sb, SB_FREEZE_WRITE);
iattr->ia_valid &= ~ATTR_SIZE;
return xfs_setattr_nonsize(ip, iattr, 0);
}
@@ -938,6 +940,7 @@ xfs_setattr_size(
out_unlock:
if (lock_flags)
xfs_iunlock(ip, lock_flags);
+ sb_end_write(inode->i_sb, SB_FREEZE_WRITE);
return error;