Module Name: src
Committed By: hannken
Date: Mon Jul 19 08:17:44 UTC 2010
Modified Files:
src/sys/fs/ntfs: ntfs_vfsops.c
Log Message:
Lock the ntnode and recheck the fnode after calling getnewvnode().
Take v_interlock while the ntnode is locked.
To generate a diff of this commit:
cvs rdiff -u -r1.82 -r1.83 src/sys/fs/ntfs/ntfs_vfsops.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/fs/ntfs/ntfs_vfsops.c
diff -u src/sys/fs/ntfs/ntfs_vfsops.c:1.82 src/sys/fs/ntfs/ntfs_vfsops.c:1.83
--- src/sys/fs/ntfs/ntfs_vfsops.c:1.82 Thu Jul 1 13:00:55 2010
+++ src/sys/fs/ntfs/ntfs_vfsops.c Mon Jul 19 08:17:44 2010
@@ -1,4 +1,4 @@
-/* $NetBSD: ntfs_vfsops.c,v 1.82 2010/07/01 13:00:55 hannken Exp $ */
+/* $NetBSD: ntfs_vfsops.c,v 1.83 2010/07/19 08:17:44 hannken Exp $ */
/*-
* Copyright (c) 1998, 1999 Semen Ustimenko
@@ -29,7 +29,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ntfs_vfsops.c,v 1.82 2010/07/01 13:00:55 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ntfs_vfsops.c,v 1.83 2010/07/19 08:17:44 hannken Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -726,6 +726,7 @@
ntmp = VFSTONTFS(mp);
*vpp = NULL;
+loop:
/* Get ntnode */
error = ntfs_ntlookup(ntmp, ino, &ip);
if (error) {
@@ -778,23 +779,41 @@
* lock has to be acquired first.
* ntfs_fget() bumped ntnode usecount, so ntnode won't be recycled
* prematurely.
+ * Take v_interlock before releasing ntnode lock to avoid races.
*/
- ntfs_ntput(ip);
-
- if (FTOV(fp)) {
- /* vget() returns error if the vnode has been recycled */
- if (vget(FTOV(fp), lkflags) == 0) {
- *vpp = FTOV(fp);
- return (0);
- }
+ vp = FTOV(fp);
+ if (vp) {
+ mutex_enter(&vp->v_interlock);
+ ntfs_ntput(ip);
+ if (vget(vp, LK_INTERLOCK | lkflags) != 0)
+ goto loop;
+ *vpp = vp;
+ return 0;
}
+ ntfs_ntput(ip);
error = getnewvnode(VT_NTFS, ntmp->ntm_mountp, ntfs_vnodeop_p, &vp);
+ ntfs_ntget(ip);
if(error) {
ntfs_frele(fp);
ntfs_ntput(ip);
return (error);
}
+ error = ntfs_fget(ntmp, ip, attrtype, attrname, &fp);
+ if (error) {
+ printf("ntfs_vget: ntfs_fget failed\n");
+ ntfs_ntput(ip);
+ return (error);
+ }
+ if (FTOV(fp)) {
+ /*
+ * Another thread beat us, put back freshly allocated
+ * vnode and retry.
+ */
+ ntfs_ntput(ip);
+ ungetnewvnode(vp);
+ goto loop;
+ }
dprintf(("ntfs_vget: vnode: %p for ntnode: %llu\n", vp,
(unsigned long long)ino));
@@ -807,6 +826,8 @@
if (ino == NTFS_ROOTINO)
vp->v_vflag |= VV_ROOT;
+ ntfs_ntput(ip);
+
if (lkflags & (LK_EXCLUSIVE | LK_SHARED)) {
error = vn_lock(vp, lkflags);
if (error) {
