On Thu, Dec 05, 2013 at 07:58:31AM -0800, Christoph Hellwig wrote: > Signed-off-by: Christoph Hellwig <hch@xxxxxx> > > Index: xfs/fs/xfs/xfs_bmap_util.c > =================================================================== > --- xfs.orig/fs/xfs/xfs_bmap_util.c 2013-12-05 11:37:57.791685284 +0100 > +++ xfs/fs/xfs/xfs_bmap_util.c 2013-12-05 11:39:43.599683113 +0100 > @@ -1147,6 +1147,7 @@ xfs_zero_remaining_bytes( > xfs_mount_t *mp = ip->i_mount; > int nimap; > int error = 0; > + uint lock_mode; > > /* > * Avoid doing I/O beyond eof - it's not necessary > @@ -1159,11 +1160,15 @@ xfs_zero_remaining_bytes( > if (endoff > XFS_ISIZE(ip)) > endoff = XFS_ISIZE(ip); > > + lock_mode = xfs_ilock_map_shared(ip); > + > bp = xfs_buf_get_uncached(XFS_IS_REALTIME_INODE(ip) ? > mp->m_rtdev_targp : mp->m_ddev_targp, > BTOBB(mp->m_sb.sb_blocksize), 0); This now holds the ilock over data IO, which is not allowed to be done as data IO completion can require the ilock to be taken. Yes, the code specifically avoids all these problems, but the general rule is that ilock is only held over metadata IO operations, not data IO. If we need data IO serialisation, then we use the iolock. So, while this protects the extent tree, it also violates other long-standing conventions for locking. Given that the code is special, I'mnot opposed to making a special rule for this one function, but it needs to be commented as to why this is a valid thing to do in this function.... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
