xfs: do not use unchecked extent indices in xfs_bunmapi

Make sure to only call xfs_iext_get_ext after we've validate the
extent index when moving on to the next index in xfs_bunmapi.  Also
remove the old workaround for too large indices that has been
superceeded by the proper fix in xfs_bmap_del_extent.

Based on an earlier patch from Lachlan McIlroy.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Lachlan McIlroy <lmcilroy@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>

diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index af655c1d460dcd7ff11f040d1078b9d4a039f742..ebcd45203c3df8a5381b9623dce1cc096ed13914 100644 (file)
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -5242,17 +5242,17 @@ xfs_bunmapi(
 nodelete:
                /*
                 * If not done go on to the next (previous) record.
-                * Reset ep in case the extents array was re-alloced.
                 */
-               ep = xfs_iext_get_ext(ifp, lastx);
                if (bno != (xfs_fileoff_t)-1 && bno >= start) {
-                       if (lastx >= XFS_IFORK_NEXTENTS(ip, whichfork) ||
-                           xfs_bmbt_get_startoff(ep) > bno) {
-                               if (--lastx >= 0)
-                                       ep = xfs_iext_get_ext(ifp, lastx);
-                       }
-                       if (lastx >= 0)
+                       if (lastx >= 0) {
+                               ep = xfs_iext_get_ext(ifp, lastx);
+                               if (xfs_bmbt_get_startoff(ep) > bno) {
+                                       if (--lastx >= 0)
+                                               ep = xfs_iext_get_ext(ifp,
+                                                                     lastx);
+                               }
                                xfs_bmbt_get_all(ep, &got);
+                       }
                        extno++;
                }
        }