From 690094cb2d13660f8e5a6bafbfc90f717191ef45 Mon Sep 17 00:00:00 2001
From: hannken <hannken@NetBSD.org>
Date: Sat, 2 Nov 2013 10:30:18 +0000
Subject: [PATCH] Stop using v_mount of an unreferenced vnode -- save the mount
 while the vnode has a reference.

---
 sys/fs/msdosfs/msdosfs_vnops.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/sys/fs/msdosfs/msdosfs_vnops.c b/sys/fs/msdosfs/msdosfs_vnops.c
index cd1cfcf5d61c..0a567f3fb111 100644
--- a/sys/fs/msdosfs/msdosfs_vnops.c
+++ b/sys/fs/msdosfs/msdosfs_vnops.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: msdosfs_vnops.c,v 1.86 2013/03/18 19:35:37 plunky Exp $	*/
+/*	$NetBSD: msdosfs_vnops.c,v 1.87 2013/11/02 10:30:18 hannken Exp $	*/
 
 /*-
  * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
@@ -48,7 +48,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: msdosfs_vnops.c,v 1.86 2013/03/18 19:35:37 plunky Exp $");
+__KERNEL_RCSID(0, "$NetBSD: msdosfs_vnops.c,v 1.87 2013/11/02 10:30:18 hannken Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -829,6 +829,7 @@ msdosfs_rename(void *v)
 	struct vnode *tdvp = ap->a_tdvp;
 	struct vnode *fvp = ap->a_fvp;
 	struct vnode *fdvp = ap->a_fdvp;
+	struct mount *mp = fdvp->v_mount;
 	struct componentname *tcnp = ap->a_tcnp;
 	struct componentname *fcnp = ap->a_fcnp;
 	struct denode *ip, *xp, *dp, *zp;
@@ -906,7 +907,7 @@ abortit:
 	}
 	VN_KNOTE(fdvp, NOTE_WRITE);		/* XXXLUKEM/XXX: right place? */
 
-	fstrans_start(fdvp->v_mount, FSTRANS_SHARED);
+	fstrans_start(mp, FSTRANS_SHARED);
 	/*
 	 * When the target exists, both the directory
 	 * and target vnodes are returned locked.
@@ -993,7 +994,7 @@ abortit:
 	 * file/directory.
 	 */
 	if ((error = uniqdosname(VTODE(tdvp), tcnp, toname)) != 0) {
-		fstrans_done(fdvp->v_mount);
+		fstrans_done(mp);
 		goto abortit;
 	}
 
@@ -1009,7 +1010,7 @@ abortit:
 		VOP_UNLOCK(fdvp);
 		vrele(ap->a_fvp);
 		vrele(tdvp);
-		fstrans_done(fdvp->v_mount);
+		fstrans_done(mp);
 		return (error);
 	}
 	if (fvp == NULL) {
@@ -1021,7 +1022,7 @@ abortit:
 		vput(fdvp);
 		vrele(ap->a_fvp);
 		vrele(tdvp);
-		fstrans_done(fdvp->v_mount);
+		fstrans_done(mp);
 		return 0;
 	}
 	VOP_UNLOCK(fdvp);
@@ -1129,7 +1130,7 @@ bad:
 	ip->de_flag &= ~DE_RENAME;
 	vrele(fdvp);
 	vrele(fvp);
-	fstrans_done(fdvp->v_mount);
+	fstrans_done(mp);
 	return (error);
 
 	/* XXX: uuuh */
@@ -1291,6 +1292,7 @@ msdosfs_rmdir(void *v)
 	} */ *ap = v;
 	struct vnode *vp = ap->a_vp;
 	struct vnode *dvp = ap->a_dvp;
+	struct mount *mp = dvp->v_mount;
 	struct componentname *cnp = ap->a_cnp;
 	struct denode *ip, *dp;
 	int error;
@@ -1305,7 +1307,7 @@ msdosfs_rmdir(void *v)
 		vput(vp);
 		return (EINVAL);
 	}
-	fstrans_start(ap->a_dvp->v_mount, FSTRANS_SHARED);
+	fstrans_start(mp, FSTRANS_SHARED);
 	/*
 	 * Verify the directory is empty (and valid).
 	 * (Rmdir ".." won't be valid since
@@ -1347,7 +1349,7 @@ out:
 	if (dvp)
 		vput(dvp);
 	vput(vp);
-	fstrans_done(ap->a_dvp->v_mount);
+	fstrans_done(mp);
 	return (error);
 }