Module Name: src
Committed By: rmind
Date: Sat Dec 18 01:18:48 UTC 2010
Modified Files:
src/sys/kern: sys_descrip.c
Log Message:
do_posix_fadvise: fix and improve previous change - add a comment with
some rationale and handle few range overflows.
Per report/discussion with y...@.
To generate a diff of this commit:
cvs rdiff -u -r1.18 -r1.19 src/sys/kern/sys_descrip.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/sys_descrip.c
diff -u src/sys/kern/sys_descrip.c:1.18 src/sys/kern/sys_descrip.c:1.19
--- src/sys/kern/sys_descrip.c:1.18 Wed Oct 27 02:58:04 2010
+++ src/sys/kern/sys_descrip.c Sat Dec 18 01:18:48 2010
@@ -1,4 +1,4 @@
-/* $NetBSD: sys_descrip.c,v 1.18 2010/10/27 02:58:04 rmind Exp $ */
+/* $NetBSD: sys_descrip.c,v 1.19 2010/12/18 01:18:48 rmind Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -67,7 +67,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sys_descrip.c,v 1.18 2010/10/27 02:58:04 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_descrip.c,v 1.19 2010/12/18 01:18:48 rmind Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -662,9 +662,8 @@
case POSIX_FADV_NORMAL:
case POSIX_FADV_RANDOM:
case POSIX_FADV_SEQUENTIAL:
-
/*
- * We ignore offset and size. must lock the file to
+ * We ignore offset and size. Must lock the file to
* do this, as f_advice is sub-word sized.
*/
mutex_enter(&fp->f_lock);
@@ -680,9 +679,22 @@
case POSIX_FADV_DONTNEED:
vp = fp->f_data;
- mutex_enter(&vp->v_interlock);
- error = VOP_PUTPAGES(vp, trunc_page(offset),
- round_page(endoffset), PGO_DEACTIVATE | PGO_CLEANIT);
+ /*
+ * Align the region to page boundaries as VOP_PUTPAGES expects
+ * by shrinking it. We shrink instead of expand because we
+ * do not want to deactivate cache outside of the requested
+ * region. It means that if the specified region is smaller
+ * than PAGE_SIZE, we do nothing.
+ */
+ if (round_page(offset) < trunc_page(endoffset) &&
+ offset <= round_page(offset)) {
+ mutex_enter(&vp->v_interlock);
+ error = VOP_PUTPAGES(vp,
+ round_page(offset), trunc_page(endoffset),
+ PGO_DEACTIVATE | PGO_CLEANIT);
+ } else {
+ error = 0;
+ }
break;
case POSIX_FADV_NOREUSE:
