struct mountlist and struct mount.mnt_list have no business being

a CIRCLEQ.  Change them to TAILQ_HEAD and TAILQ_ENTRY respectively.

This removes ugly  mp != (void*)&mountlist  comparisons.

Requested by:   phk
Submitted by:   Jake Burkholder jake@checker.org
PR:             14967

8 files changed, 50 insertions, 54 deletions

diff --git a/sys/kern/init_main.c b/sys/kern/init_main.c
index ec9cf85..484cfa4 100644
--- a/sys/kern/init_main.c
+++ b/sys/kern/init_main.c
@@ -447,7 +447,7 @@ xxx_vfs_root_fdtab(dummy)
 	register struct filedesc0	*fdp = &filedesc0;
 
 	/* Get the vnode for '/'.  Set fdp->fd_fd.fd_cdir to reference it. */
-	if (VFS_ROOT(CIRCLEQ_FIRST(&mountlist), &rootvnode))
+	if (VFS_ROOT(TAILQ_FIRST(&mountlist), &rootvnode))
 		panic("cannot find root vnode");
 	fdp->fd_fd.fd_cdir = rootvnode;
 	VREF(fdp->fd_fd.fd_cdir);
diff --git a/sys/kern/kern_shutdown.c b/sys/kern/kern_shutdown.c
index 7ee7cc6..cc7e9ff 100644
--- a/sys/kern/kern_shutdown.c
+++ b/sys/kern/kern_shutdown.c
@@ -229,7 +229,7 @@ boot(howto)
 			if (((bp->b_flags&B_INVAL) == 0 && BUF_REFCNT(bp)) ||
 			    ((bp->b_flags & (B_DELWRI|B_INVAL)) == B_DELWRI)) {
 				if (bp->b_dev == NODEV) {
-					CIRCLEQ_REMOVE(&mountlist,
+					TAILQ_REMOVE(&mountlist,
 					    bp->b_vp->v_mount, mnt_list);
 					continue;
 				}
diff --git a/sys/kern/vfs_conf.c b/sys/kern/vfs_conf.c
index 8932e41..c2fa605 100644
--- a/sys/kern/vfs_conf.c
+++ b/sys/kern/vfs_conf.c
@@ -213,7 +213,7 @@ done:
 
 		/* register with list of mounted filesystems */
 		simple_lock(&mountlist_slock);
-		CIRCLEQ_INSERT_HEAD(&mountlist, mp, mnt_list);
+		TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list);
 		simple_unlock(&mountlist_slock);
 
 		/* sanity check system clock against root filesystem timestamp */
diff --git a/sys/kern/vfs_export.c b/sys/kern/vfs_export.c
index 6d339cf..fc850ff 100644
--- a/sys/kern/vfs_export.c
+++ b/sys/kern/vfs_export.c
@@ -116,7 +116,7 @@ int vfs_ioopt = 0;
 SYSCTL_INT(_vfs, OID_AUTO, ioopt, CTLFLAG_RW, &vfs_ioopt, 0, "");
 #endif
 
-struct mntlist mountlist;	/* mounted filesystem list */
+struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist); /* mounted fs */
 struct simplelock mountlist_slock;
 struct simplelock mntvnode_slock;
 int	nfs_mount_type = -1;
@@ -172,7 +172,6 @@ vntblinit()
 	TAILQ_INIT(&vnode_free_list);
 	TAILQ_INIT(&vnode_tobefree_list);
 	simple_lock_init(&vnode_free_list_slock);
-	CIRCLEQ_INIT(&mountlist);
 	vnode_zone = zinit("VNODE", sizeof (struct vnode), 0, 0, 5);
 	/*
 	 * Initialize the filesystem syncer.
@@ -315,7 +314,7 @@ vfs_getvfs(fsid)
 	register struct mount *mp;
 
 	simple_lock(&mountlist_slock);
-	CIRCLEQ_FOREACH(mp, &mountlist, mnt_list) {
+	TAILQ_FOREACH(mp, &mountlist, mnt_list) {
 		if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
 		    mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
 			simple_unlock(&mountlist_slock);
@@ -1973,9 +1972,9 @@ DB_SHOW_COMMAND(lockedvnodes, lockedvnodes)
 
 	printf("Locked vnodes\n");
 	simple_lock(&mountlist_slock);
-	for (mp = CIRCLEQ_FIRST(&mountlist); mp != (void *)&mountlist; mp = nmp) {
+	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
 		if (vfs_busy(mp, LK_NOWAIT, &mountlist_slock, p)) {
-			nmp = CIRCLEQ_NEXT(mp, mnt_list);
+			nmp = TAILQ_NEXT(mp, mnt_list);
 			continue;
 		}
 		LIST_FOREACH(vp, &mp->mnt_vnodelist, v_mntvnodes) {
@@ -1983,7 +1982,7 @@ DB_SHOW_COMMAND(lockedvnodes, lockedvnodes)
 				vprint((char *)0, vp);
 		}
 		simple_lock(&mountlist_slock);
-		nmp = CIRCLEQ_NEXT(mp, mnt_list);
+		nmp = TAILQ_NEXT(mp, mnt_list);
 		vfs_unbusy(mp, p);
 	}
 	simple_unlock(&mountlist_slock);
@@ -2091,10 +2090,9 @@ sysctl_vnode SYSCTL_HANDLER_ARGS
 			(numvnodes + KINFO_VNODESLOP) * (VPTRSZ + VNODESZ)));
 
 	simple_lock(&mountlist_slock);
-	mp = CIRCLEQ_FIRST(&mountlist);
-	for (; mp != (void *)&mountlist; mp = nmp) {
+	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
 		if (vfs_busy(mp, LK_NOWAIT, &mountlist_slock, p)) {
-			nmp = CIRCLEQ_NEXT(mp, mnt_list);
+			nmp = TAILQ_NEXT(mp, mnt_list);
 			continue;
 		}
 again:
@@ -2120,7 +2118,7 @@ again:
 		}
 		simple_unlock(&mntvnode_slock);
 		simple_lock(&mountlist_slock);
-		nmp = CIRCLEQ_NEXT(mp, mnt_list);
+		nmp = TAILQ_NEXT(mp, mnt_list);
 		vfs_unbusy(mp, p);
 	}
 	simple_unlock(&mountlist_slock);
@@ -2159,7 +2157,7 @@ vfs_mountedon(vp)
 void
 vfs_unmountall()
 {
-	struct mount *mp, *nmp;
+	struct mount *mp;
 	struct proc *p;
 	int error;
 
@@ -2170,17 +2168,19 @@ vfs_unmountall()
 	/*
 	 * Since this only runs when rebooting, it is not interlocked.
 	 */
-	mp = CIRCLEQ_LAST(&mountlist);
-	for (; mp != (void *)&mountlist; mp = nmp) {
-		nmp = CIRCLEQ_PREV(mp, mnt_list);
+	while(!TAILQ_EMPTY(&mountlist)) {
+		mp = TAILQ_LAST(&mountlist, mntlist);
 		error = dounmount(mp, MNT_FORCE, p);
 		if (error) {
+			TAILQ_REMOVE(&mountlist, mp, mnt_list);
 			printf("unmount of %s failed (",
 			    mp->mnt_stat.f_mntonname);
 			if (error == EBUSY)
 				printf("BUSY)\n");
 			else
 				printf("%d)\n", error);
+		} else {
+			/* The unmount has removed mp from the mountlist */
 		}
 	}
 }
diff --git a/sys/kern/vfs_extattr.c b/sys/kern/vfs_extattr.c
index e0045c1..4d5d394 100644
--- a/sys/kern/vfs_extattr.c
+++ b/sys/kern/vfs_extattr.c
@@ -331,7 +331,7 @@ update:
 		vp->v_mountedhere = mp;
 		simple_unlock(&vp->v_interlock);
 		simple_lock(&mountlist_slock);
-		CIRCLEQ_INSERT_TAIL(&mountlist, mp, mnt_list);
+		TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
 		simple_unlock(&mountlist_slock);
 		checkdirs(vp);
 		VOP_UNLOCK(vp, 0, p);
@@ -494,7 +494,7 @@ dounmount(mp, flags, p)
 			wakeup((caddr_t)mp);
 		return (error);
 	}
-	CIRCLEQ_REMOVE(&mountlist, mp, mnt_list);
+	TAILQ_REMOVE(&mountlist, mp, mnt_list);
 	if ((coveredvp = mp->mnt_vnodecovered) != NULLVP) {
 		coveredvp->v_mountedhere = (struct mount *)0;
 		vrele(coveredvp);
@@ -533,10 +533,9 @@ sync(p, uap)
 	int asyncflag;
 
 	simple_lock(&mountlist_slock);
-	mp = CIRCLEQ_FIRST(&mountlist);
-	for (; mp != (void *)&mountlist; mp = nmp) {
+	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
 		if (vfs_busy(mp, LK_NOWAIT, &mountlist_slock, p)) {
-			nmp = CIRCLEQ_NEXT(mp, mnt_list);
+			nmp = TAILQ_NEXT(mp, mnt_list);
 			continue;
 		}
 		if ((mp->mnt_flag & MNT_RDONLY) == 0) {
@@ -548,7 +547,7 @@ sync(p, uap)
 			mp->mnt_flag |= asyncflag;
 		}
 		simple_lock(&mountlist_slock);
-		nmp = CIRCLEQ_NEXT(mp, mnt_list);
+		nmp = TAILQ_NEXT(mp, mnt_list);
 		vfs_unbusy(mp, p);
 	}
 	simple_unlock(&mountlist_slock);
@@ -718,10 +717,9 @@ getfsstat(p, uap)
 	sfsp = (caddr_t)SCARG(uap, buf);
 	count = 0;
 	simple_lock(&mountlist_slock);
-	mp = CIRCLEQ_FIRST(&mountlist);
-	for (; mp != (void *)&mountlist; mp = nmp) {
+	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
 		if (vfs_busy(mp, LK_NOWAIT, &mountlist_slock, p)) {
-			nmp = CIRCLEQ_NEXT(mp, mnt_list);
+			nmp = TAILQ_NEXT(mp, mnt_list);
 			continue;
 		}
 		if (sfsp && count < maxcount) {
@@ -735,7 +733,7 @@ getfsstat(p, uap)
 			    (SCARG(uap, flags) & MNT_WAIT)) &&
 			    (error = VFS_STATFS(mp, sp, p))) {
 				simple_lock(&mountlist_slock);
-				nmp = CIRCLEQ_NEXT(mp, mnt_list);
+				nmp = TAILQ_NEXT(mp, mnt_list);
 				vfs_unbusy(mp, p);
 				continue;
 			}
@@ -749,7 +747,7 @@ getfsstat(p, uap)
 		}
 		count++;
 		simple_lock(&mountlist_slock);
-		nmp = CIRCLEQ_NEXT(mp, mnt_list);
+		nmp = TAILQ_NEXT(mp, mnt_list);
 		vfs_unbusy(mp, p);
 	}
 	simple_unlock(&mountlist_slock);
diff --git a/sys/kern/vfs_mount.c b/sys/kern/vfs_mount.c
index 8932e41..c2fa605 100644
--- a/sys/kern/vfs_mount.c
+++ b/sys/kern/vfs_mount.c
@@ -213,7 +213,7 @@ done:
 
 		/* register with list of mounted filesystems */
 		simple_lock(&mountlist_slock);
-		CIRCLEQ_INSERT_HEAD(&mountlist, mp, mnt_list);
+		TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list);
 		simple_unlock(&mountlist_slock);
 
 		/* sanity check system clock against root filesystem timestamp */
diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index 6d339cf..fc850ff 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -116,7 +116,7 @@ int vfs_ioopt = 0;
 SYSCTL_INT(_vfs, OID_AUTO, ioopt, CTLFLAG_RW, &vfs_ioopt, 0, "");
 #endif
 
-struct mntlist mountlist;	/* mounted filesystem list */
+struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist); /* mounted fs */
 struct simplelock mountlist_slock;
 struct simplelock mntvnode_slock;
 int	nfs_mount_type = -1;
@@ -172,7 +172,6 @@ vntblinit()
 	TAILQ_INIT(&vnode_free_list);
 	TAILQ_INIT(&vnode_tobefree_list);
 	simple_lock_init(&vnode_free_list_slock);
-	CIRCLEQ_INIT(&mountlist);
 	vnode_zone = zinit("VNODE", sizeof (struct vnode), 0, 0, 5);
 	/*
 	 * Initialize the filesystem syncer.
@@ -315,7 +314,7 @@ vfs_getvfs(fsid)
 	register struct mount *mp;
 
 	simple_lock(&mountlist_slock);
-	CIRCLEQ_FOREACH(mp, &mountlist, mnt_list) {
+	TAILQ_FOREACH(mp, &mountlist, mnt_list) {
 		if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
 		    mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
 			simple_unlock(&mountlist_slock);
@@ -1973,9 +1972,9 @@ DB_SHOW_COMMAND(lockedvnodes, lockedvnodes)
 
 	printf("Locked vnodes\n");
 	simple_lock(&mountlist_slock);
-	for (mp = CIRCLEQ_FIRST(&mountlist); mp != (void *)&mountlist; mp = nmp) {
+	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
 		if (vfs_busy(mp, LK_NOWAIT, &mountlist_slock, p)) {
-			nmp = CIRCLEQ_NEXT(mp, mnt_list);
+			nmp = TAILQ_NEXT(mp, mnt_list);
 			continue;
 		}
 		LIST_FOREACH(vp, &mp->mnt_vnodelist, v_mntvnodes) {
@@ -1983,7 +1982,7 @@ DB_SHOW_COMMAND(lockedvnodes, lockedvnodes)
 				vprint((char *)0, vp);
 		}
 		simple_lock(&mountlist_slock);
-		nmp = CIRCLEQ_NEXT(mp, mnt_list);
+		nmp = TAILQ_NEXT(mp, mnt_list);
 		vfs_unbusy(mp, p);
 	}
 	simple_unlock(&mountlist_slock);
@@ -2091,10 +2090,9 @@ sysctl_vnode SYSCTL_HANDLER_ARGS
 			(numvnodes + KINFO_VNODESLOP) * (VPTRSZ + VNODESZ)));
 
 	simple_lock(&mountlist_slock);
-	mp = CIRCLEQ_FIRST(&mountlist);
-	for (; mp != (void *)&mountlist; mp = nmp) {
+	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
 		if (vfs_busy(mp, LK_NOWAIT, &mountlist_slock, p)) {
-			nmp = CIRCLEQ_NEXT(mp, mnt_list);
+			nmp = TAILQ_NEXT(mp, mnt_list);
 			continue;
 		}
 again:
@@ -2120,7 +2118,7 @@ again:
 		}
 		simple_unlock(&mntvnode_slock);
 		simple_lock(&mountlist_slock);
-		nmp = CIRCLEQ_NEXT(mp, mnt_list);
+		nmp = TAILQ_NEXT(mp, mnt_list);
 		vfs_unbusy(mp, p);
 	}
 	simple_unlock(&mountlist_slock);
@@ -2159,7 +2157,7 @@ vfs_mountedon(vp)
 void
 vfs_unmountall()
 {
-	struct mount *mp, *nmp;
+	struct mount *mp;
 	struct proc *p;
 	int error;
 
@@ -2170,17 +2168,19 @@ vfs_unmountall()
 	/*
 	 * Since this only runs when rebooting, it is not interlocked.
 	 */
-	mp = CIRCLEQ_LAST(&mountlist);
-	for (; mp != (void *)&mountlist; mp = nmp) {
-		nmp = CIRCLEQ_PREV(mp, mnt_list);
+	while(!TAILQ_EMPTY(&mountlist)) {
+		mp = TAILQ_LAST(&mountlist, mntlist);
 		error = dounmount(mp, MNT_FORCE, p);
 		if (error) {
+			TAILQ_REMOVE(&mountlist, mp, mnt_list);
 			printf("unmount of %s failed (",
 			    mp->mnt_stat.f_mntonname);
 			if (error == EBUSY)
 				printf("BUSY)\n");
 			else
 				printf("%d)\n", error);
+		} else {
+			/* The unmount has removed mp from the mountlist */
 		}
 	}
 }
diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c
index e0045c1..4d5d394 100644
--- a/sys/kern/vfs_syscalls.c
+++ b/sys/kern/vfs_syscalls.c
@@ -331,7 +331,7 @@ update:
 		vp->v_mountedhere = mp;
 		simple_unlock(&vp->v_interlock);
 		simple_lock(&mountlist_slock);
-		CIRCLEQ_INSERT_TAIL(&mountlist, mp, mnt_list);
+		TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
 		simple_unlock(&mountlist_slock);
 		checkdirs(vp);
 		VOP_UNLOCK(vp, 0, p);
@@ -494,7 +494,7 @@ dounmount(mp, flags, p)
 			wakeup((caddr_t)mp);
 		return (error);
 	}
-	CIRCLEQ_REMOVE(&mountlist, mp, mnt_list);
+	TAILQ_REMOVE(&mountlist, mp, mnt_list);
 	if ((coveredvp = mp->mnt_vnodecovered) != NULLVP) {
 		coveredvp->v_mountedhere = (struct mount *)0;
 		vrele(coveredvp);
@@ -533,10 +533,9 @@ sync(p, uap)
 	int asyncflag;
 
 	simple_lock(&mountlist_slock);
-	mp = CIRCLEQ_FIRST(&mountlist);
-	for (; mp != (void *)&mountlist; mp = nmp) {
+	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
 		if (vfs_busy(mp, LK_NOWAIT, &mountlist_slock, p)) {
-			nmp = CIRCLEQ_NEXT(mp, mnt_list);
+			nmp = TAILQ_NEXT(mp, mnt_list);
 			continue;
 		}
 		if ((mp->mnt_flag & MNT_RDONLY) == 0) {
@@ -548,7 +547,7 @@ sync(p, uap)
 			mp->mnt_flag |= asyncflag;
 		}
 		simple_lock(&mountlist_slock);
-		nmp = CIRCLEQ_NEXT(mp, mnt_list);
+		nmp = TAILQ_NEXT(mp, mnt_list);
 		vfs_unbusy(mp, p);
 	}
 	simple_unlock(&mountlist_slock);
@@ -718,10 +717,9 @@ getfsstat(p, uap)
 	sfsp = (caddr_t)SCARG(uap, buf);
 	count = 0;
 	simple_lock(&mountlist_slock);
-	mp = CIRCLEQ_FIRST(&mountlist);
-	for (; mp != (void *)&mountlist; mp = nmp) {
+	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
 		if (vfs_busy(mp, LK_NOWAIT, &mountlist_slock, p)) {
-			nmp = CIRCLEQ_NEXT(mp, mnt_list);
+			nmp = TAILQ_NEXT(mp, mnt_list);
 			continue;
 		}
 		if (sfsp && count < maxcount) {
@@ -735,7 +733,7 @@ getfsstat(p, uap)
 			    (SCARG(uap, flags) & MNT_WAIT)) &&
 			    (error = VFS_STATFS(mp, sp, p))) {
 				simple_lock(&mountlist_slock);
-				nmp = CIRCLEQ_NEXT(mp, mnt_list);
+				nmp = TAILQ_NEXT(mp, mnt_list);
 				vfs_unbusy(mp, p);
 				continue;
 			}
@@ -749,7 +747,7 @@ getfsstat(p, uap)
 		}
 		count++;
 		simple_lock(&mountlist_slock);
-		nmp = CIRCLEQ_NEXT(mp, mnt_list);
+		nmp = TAILQ_NEXT(mp, mnt_list);
 		vfs_unbusy(mp, p);
 	}
 	simple_unlock(&mountlist_slock);