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

[Eric Sandeen <sandeen@xxxxxxxxxxx>]

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;
 
 out_trans_abort: