svn commit: r295716 - head/sys/kern

[Konstantin Belousov]

Author: kib
Date: Wed Feb 17 19:39:57 2016
New Revision: 295716
URL: https://svnweb.freebsd.org/changeset/base/295716

Log:
  In bnoreuselist(), check both ends of the specified logical block
  numbers range.
  
  This effectively skips indirect and extdata blocks on the buffer
  queue.  Since their logical block numbers are negative, bnoreuselist()
  could loop infinitely.
  
  Reported and tested by:	pho
  Sponsored by:	The FreeBSD Foundation
  MFC after:	1 week

Modified:
  head/sys/kern/vfs_subr.c

Modified: head/sys/kern/vfs_subr.c
==============================================================================
--- head/sys/kern/vfs_subr.c	Wed Feb 17 19:11:09 2016	(r295715)
+++ head/sys/kern/vfs_subr.c	Wed Feb 17 19:39:57 2016	(r295716)
@@ -1673,7 +1673,8 @@ bnoreuselist(struct bufv *bufv, struct b
 	for (lblkno = startn;;) {
 again:
 		bp = BUF_PCTRIE_LOOKUP_GE(&bufv->bv_root, lblkno);
-		if (bp == NULL || bp->b_lblkno >= endn)
+		if (bp == NULL || bp->b_lblkno >= endn ||
+		    bp->b_lblkno < startn)
 			break;
 		error = BUF_TIMELOCK(bp, LK_EXCLUSIVE | LK_SLEEPFAIL |
 		    LK_INTERLOCK, BO_LOCKPTR(bo), "brlsfl", 0, 0);