NTFS: Fix a nasty runlist merge bug when merging two holes.

Signed-off-by: NAnton Altaparmakov <aia21@cantab.net>

fs/ntfs/ChangeLog

@@ -72,9 +72,10 @@ ToDo/Notes:
 	  runlist.  This allows us to find runlist elements with the runlist
 	  lock already held without having to drop and reacquire it around the
 	  call.  Adapt all callers.
-	- Change time to u64 time.h::ntfs2utc() as it otherwise generates a
+	- Change time to u64 in time.h::ntfs2utc() as it otherwise generates a
 	  warning in the do_div() call on sparc32.  Thanks to Meelis Roos for
 	  the report and analysis of the warning.
+	- Fix a nasty runlist merge bug when merging two holes.
 
 2.1.22 - Many bug and race fixes and error handling improvements.
 

fs/ntfs/runlist.c

@@ -113,8 +113,11 @@ static inline BOOL ntfs_are_rl_mergeable(runlist_element *dst,
 	BUG_ON(!dst);
 	BUG_ON(!src);
 
-	if ((dst->lcn < 0) || (src->lcn < 0))     /* Are we merging holes? */
+	if ((dst->lcn < 0) || (src->lcn < 0)) {   /* Are we merging holes? */
+		if (dst->lcn == LCN_HOLE && src->lcn == LCN_HOLE)
+			return TRUE;
 		return FALSE;
+	}
 	if ((dst->lcn + dst->length) != src->lcn) /* Are the runs contiguous? */
 		return FALSE;
 	if ((dst->vcn + dst->length) != src->vcn) /* Are the runs misaligned? */