[src/trunk]: src/sys/nfs fix panic (assertion failure) on error case.

[yamt <yamt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/36b02fa3eb58
branches:  trunk
changeset: 538757:36b02fa3eb58
user:      yamt <yamt%NetBSD.org@localhost>
date:      Tue Oct 29 10:15:16 2002 +0000

description:
fix panic (assertion failure) on error case.
if uiomove is failed, we should clean up pages past eof.

the problem reported by kay.
ok'ed by Chuck Silvers.

diffstat:

 sys/nfs/nfs_bio.c |  20 ++++++++++++++++----
 1 files changed, 16 insertions(+), 4 deletions(-)

diffs (60 lines):

diff -r aa2bb1596d67 -r 36b02fa3eb58 sys/nfs/nfs_bio.c
--- a/sys/nfs/nfs_bio.c Tue Oct 29 08:59:36 2002 +0000
+++ b/sys/nfs/nfs_bio.c Tue Oct 29 10:15:16 2002 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: nfs_bio.c,v 1.84 2002/10/23 09:14:48 jdolecek Exp $    */
+/*     $NetBSD: nfs_bio.c,v 1.85 2002/10/29 10:15:16 yamt Exp $        */
 
 /*
  * Copyright (c) 1989, 1993
@@ -39,7 +39,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: nfs_bio.c,v 1.84 2002/10/23 09:14:48 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: nfs_bio.c,v 1.85 2002/10/29 10:15:16 yamt Exp $");
 
 #include "opt_nfs.h"
 #include "opt_ddb.h"
@@ -591,6 +591,8 @@
 
        origoff = uio->uio_offset;
        do {
+               boolean_t extending; /* if we are extending whole pages */
+               u_quad_t oldsize;
                oldoff = uio->uio_offset;
                bytelen = uio->uio_resid;
 
@@ -616,13 +618,15 @@
 #endif
                nfsstats.biocache_writes++;
 
+               oldsize = np->n_size;
                np->n_flag |= NMODIFIED;
                if (np->n_size < uio->uio_offset + bytelen) {
                        np->n_size = uio->uio_offset + bytelen;
                }
-               if ((uio->uio_offset & PAGE_MASK) == 0 &&
+               extending = ((uio->uio_offset & PAGE_MASK) == 0 &&
                    (bytelen & PAGE_MASK) == 0 &&
-                   uio->uio_offset >= vp->v_size) {
+                   uio->uio_offset >= vp->v_size);
+               if (extending) {
                        win = ubc_alloc(&vp->v_uobj, uio->uio_offset, &bytelen,
                            UBC_WRITE | UBC_FAULTBUSY);
                } else {
@@ -632,6 +636,14 @@
                error = uiomove(win, bytelen, uio);
                ubc_release(win, 0);
                if (error) {
+                       if (extending) {
+                               /*
+                                * backout size and free pages past eof.
+                                */
+                               np->n_size = oldsize;
+                               (void)VOP_PUTPAGES(vp, round_page(vp->v_size),
+                                   0, PGO_SYNCIO | PGO_FREE);
+                       }
                        break;
                }
                wrotedta = 1;