[Midnightbsd-cvs] src [8492] trunk/sys/kern/vfs_bio.c: do not ignore zero address.

[laffer1 at midnightbsd.org]

Revision: 8492
          http://svnweb.midnightbsd.org/src/?rev=8492
Author:   laffer1
Date:     2016-09-18 18:37:50 -0400 (Sun, 18 Sep 2016)
Log Message:
-----------
do not ignore zero address.

Modified Paths:
--------------
    trunk/sys/kern/vfs_bio.c

Modified: trunk/sys/kern/vfs_bio.c
===================================================================
--- trunk/sys/kern/vfs_bio.c	2016-09-18 22:37:30 UTC (rev 8491)
+++ trunk/sys/kern/vfs_bio.c	2016-09-18 22:37:50 UTC (rev 8492)
@@ -2139,15 +2139,16 @@
 
 		if (maxsize != bp->b_kvasize) {
 			vm_offset_t addr = 0;
+			int rv;
 
 			bfreekva(bp);
 
 			vm_map_lock(buffer_map);
 			if (vm_map_findspace(buffer_map,
-				vm_map_min(buffer_map), maxsize, &addr)) {
+			    vm_map_min(buffer_map), maxsize, &addr)) {
 				/*
-				 * Uh oh.  Buffer map is to fragmented.  We
-				 * must defragment the map.
+				 * Buffer map is too fragmented.
+				 * We must defragment the map.
 				 */
 				atomic_add_int(&bufdefragcnt, 1);
 				vm_map_unlock(buffer_map);
@@ -2156,22 +2157,21 @@
 				brelse(bp);
 				goto restart;
 			}
-			if (addr) {
-				vm_map_insert(buffer_map, NULL, 0,
-					addr, addr + maxsize,
-					VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
-
-				bp->b_kvabase = (caddr_t) addr;
-				bp->b_kvasize = maxsize;
-				atomic_add_long(&bufspace, bp->b_kvasize);
-				atomic_add_int(&bufreusecnt, 1);
-			}
+			rv = vm_map_insert(buffer_map, NULL, 0, addr,
+			    addr + maxsize, VM_PROT_ALL, VM_PROT_ALL,
+			    MAP_NOFAULT);
+			KASSERT(rv == KERN_SUCCESS,
+			    ("vm_map_insert(buffer_map) rv %d", rv));
 			vm_map_unlock(buffer_map);
+			bp->b_kvabase = (caddr_t)addr;
+			bp->b_kvasize = maxsize;
+			atomic_add_long(&bufspace, bp->b_kvasize);
+			atomic_add_int(&bufreusecnt, 1);
 		}
 		bp->b_saveaddr = bp->b_kvabase;
 		bp->b_data = bp->b_saveaddr;
 	}
-	return(bp);
+	return (bp);
 }
 
 /*