[XFS] Wait for all I/O on truncate to zero file size It's possible to have outstanding xfs_ioend_t's queued when the file size is zero. This can happen in the direct I/O path when a direct I/O write fails due to ENOSPC. In this case the xfs_ioend_t will still be queued (ie xfs_end_io_direct() does not know that the I/O failed so can't force the xfs_ioend_t to be flushed synchronously). When we truncate a file on unlink we don't know to wait for these xfs_ioend_ts and we can have a use-after-free situation if the inode is reclaimed before the xfs_ioend_t is finally processed. As was suggested by Dave Chinner lets wait for all I/Os to complete when truncating the file size to zero. SGI-PV: 981668 SGI-Modid: xfs-linux-melb:xfs-kern:32216a Signed-off-by: Lachlan McIlroy <lachlan@sgi.com> Signed-off-by: Christoph Hellwig <hch@infradead.org>
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index cc0474d..2b1294b 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c
@@ -1450,7 +1450,7 @@ mp = ip->i_mount; /* wait for the completion of any pending DIOs */ - if (new_size < ip->i_size) + if (new_size == 0 || new_size < ip->i_size) vn_iowait(ip); /*