svn commit: r246289 - head/sys/ufs/ffs

[Kirk McKusick]

Author: mckusick
Date: Sun Feb  3 17:16:32 2013
New Revision: 246289
URL: http://svnweb.freebsd.org/changeset/base/246289

Log:
  For UFS2 i_blocks is unsigned. The current "sanity" check that it
  has gone below zero after the blocks in its inode are freed is a
  no-op which the compiler fails to warn about because of the use of
  the DIP macro. Change the sanity check to compare the number of
  blocks being freed against the value i_blocks. If the number of
  blocks being freed exceeds i_blocks, just set i_blocks to zero.
  
  Reported by: Pedro Giffuni (pfg@)
  MFC after:   2 weeks

Modified:
  head/sys/ufs/ffs/ffs_inode.c

Modified: head/sys/ufs/ffs/ffs_inode.c
==============================================================================
--- head/sys/ufs/ffs/ffs_inode.c	Sun Feb  3 15:54:57 2013	(r246288)
+++ head/sys/ufs/ffs/ffs_inode.c	Sun Feb  3 17:16:32 2013	(r246289)
@@ -546,9 +546,9 @@ done:
 	 */
 	ip->i_size = length;
 	DIP_SET(ip, i_size, length);
-	DIP_SET(ip, i_blocks, DIP(ip, i_blocks) - blocksreleased);
-
-	if (DIP(ip, i_blocks) < 0)			/* sanity */
+	if (DIP(ip, i_blocks) >= blocksreleased)
+		DIP_SET(ip, i_blocks, DIP(ip, i_blocks) - blocksreleased);
+	else	/* sanity */
 		DIP_SET(ip, i_blocks, 0);
 	ip->i_flag |= IN_CHANGE;
 #ifdef QUOTA