Remove mntvnode_mtx and replace it with per-mountpoint mutex.

Introduce two new macros MNT_ILOCK(mp)/MNT_IUNLOCK(mp) to
operate on this mutex transparently.

Eventually new mutex will be protecting more fields in
struct mount, not only vnode list.

Discussed with: jeff

sys/coda/coda_subr.c

@@ -307,12 +307,12 @@ coda_unmounting(whoIam)
 void
 coda_checkunmounting(mp)
 	struct mount *mp;
-{	
+{
 	register struct vnode *vp, *nvp;
 	struct cnode *cp;
 	int count = 0, bad = 0;
 
-	mtx_lock(&mntvnode_mtx);
+	MNT_ILOCK(mp);
 	for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp; vp = nvp) {
 		nvp = TAILQ_NEXT(vp, v_nmntvnodes);
 		if (vp->v_mount != mp)
@@ -331,7 +331,7 @@ coda_checkunmounting(mp)
 		}
 		VI_UNLOCK(vp);
 	}
-	mtx_unlock(&mntvnode_mtx);
+	MNT_IUNLOCK(mp);
 }
 
 void

sys/fs/coda/coda_subr.c

@@ -307,12 +307,12 @@ coda_unmounting(whoIam)
 void
 coda_checkunmounting(mp)
 	struct mount *mp;
-{	
+{
 	register struct vnode *vp, *nvp;
 	struct cnode *cp;
 	int count = 0, bad = 0;
 
-	mtx_lock(&mntvnode_mtx);
+	MNT_ILOCK(mp);
 	for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp; vp = nvp) {
 		nvp = TAILQ_NEXT(vp, v_nmntvnodes);
 		if (vp->v_mount != mp)
@@ -331,7 +331,7 @@ coda_checkunmounting(mp)
 		}
 		VI_UNLOCK(vp);
 	}
-	mtx_unlock(&mntvnode_mtx);
+	MNT_IUNLOCK(mp);
 }
 
 void

sys/fs/msdosfs/msdosfs_vfsops.c

@@ -778,7 +778,7 @@ msdosfs_sync(mp, waitfor, cred, td)
 	/*
 	 * Write back each (modified) denode.
 	 */
-	mtx_lock(&mntvnode_mtx);
+	MNT_ILOCK(mp);
 loop:
 	for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) {
 		/*
@@ -794,19 +794,19 @@ msdosfs_sync(mp, waitfor, cred, td)
 			VI_UNLOCK(vp);
 			continue;
 		}
-		mtx_unlock(&mntvnode_mtx);
+		MNT_IUNLOCK(mp);
 		dep = VTODE(vp);
 		if (vp->v_type == VNON ||
 		    ((dep->de_flag &
 		    (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0 &&
 		    (TAILQ_EMPTY(&vp->v_dirtyblkhd) || waitfor == MNT_LAZY))) {
 			VI_UNLOCK(vp);
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			continue;
 		}
 		error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, td);
 		if (error) {
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			if (error == ENOENT)
 				goto loop;
 			continue;
@@ -816,9 +816,9 @@ msdosfs_sync(mp, waitfor, cred, td)
 			allerror = error;
 		VOP_UNLOCK(vp, 0, td);
 		vrele(vp);
-		mtx_lock(&mntvnode_mtx);
+		MNT_ILOCK(mp);
 	}
-	mtx_unlock(&mntvnode_mtx);
+	MNT_IUNLOCK(mp);
 
 	/*
 	 * Flush filesystem control info.

sys/gnu/ext2fs/ext2_vfsops.c

@@ -569,10 +569,10 @@ ext2_reload(mountp, cred, td)
 	brelse(bp);
 
 loop:
-	mtx_lock(&mntvnode_mtx);
+	MNT_ILOCK(mp);
 	for (vp = TAILQ_FIRST(&mountp->mnt_nvnodelist); vp != NULL; vp = nvp) {
 		if (vp->v_mount != mountp) {
-			mtx_unlock(&mntvnode_mtx);
+			MNT_IUNLOCK(mp);
 			goto loop;
 		}
 		nvp = TAILQ_NEXT(vp, v_nmntvnodes);
@@ -581,7 +581,7 @@ ext2_reload(mountp, cred, td)
 			VI_UNLOCK(vp);
 			continue;
 		}
-		mtx_unlock(&mntvnode_mtx);
+		MNT_IUNLOCK(mp);
 		/*
 		 * Step 4: invalidate all inactive vnodes.
 		 */
@@ -614,9 +614,9 @@ ext2_reload(mountp, cred, td)
 		brelse(bp);
 		VOP_UNLOCK(vp, 0, td);
 		vrele(vp);
-		mtx_lock(&mntvnode_mtx);
+		MNT_ILOCK(mp);
 	}
-	mtx_unlock(&mntvnode_mtx);
+	MNT_IUNLOCK(mp);
 	return (0);
 }
 
@@ -901,7 +901,7 @@ ext2_sync(mp, waitfor, cred, td)
 	/*
 	 * Write back each (modified) inode.
 	 */
-	mtx_lock(&mntvnode_mtx);
+	MNT_ILOCK(mp);
 loop:
 	for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) {
 		/*
@@ -916,19 +916,19 @@ ext2_sync(mp, waitfor, cred, td)
 			VI_UNLOCK(vp);
 			continue;
 		}
-		mtx_unlock(&mntvnode_mtx);
+		MNT_IUNLOCK(mp);
 		ip = VTOI(vp);
 		if (vp->v_type == VNON ||
 		    ((ip->i_flag &
 		    (IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE)) == 0 &&
 		    (TAILQ_EMPTY(&vp->v_dirtyblkhd) || waitfor == MNT_LAZY))) {
 			VI_UNLOCK(vp);
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			continue;
 		}
 		error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, td);
 		if (error) {
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			if (error == ENOENT)
 				goto loop;
 			continue;
@@ -937,9 +937,9 @@ ext2_sync(mp, waitfor, cred, td)
 			allerror = error;
 		VOP_UNLOCK(vp, 0, td);
 		vrele(vp);
-		mtx_lock(&mntvnode_mtx);
+		MNT_ILOCK(mp);
 	}
-	mtx_unlock(&mntvnode_mtx);
+	MNT_IUNLOCK(mp);
 	/*
 	 * Force stale file system control information to be flushed.
 	 */

sys/gnu/fs/ext2fs/ext2_vfsops.c

@@ -569,10 +569,10 @@ ext2_reload(mountp, cred, td)
 	brelse(bp);
 
 loop:
-	mtx_lock(&mntvnode_mtx);
+	MNT_ILOCK(mp);
 	for (vp = TAILQ_FIRST(&mountp->mnt_nvnodelist); vp != NULL; vp = nvp) {
 		if (vp->v_mount != mountp) {
-			mtx_unlock(&mntvnode_mtx);
+			MNT_IUNLOCK(mp);
 			goto loop;
 		}
 		nvp = TAILQ_NEXT(vp, v_nmntvnodes);
@@ -581,7 +581,7 @@ ext2_reload(mountp, cred, td)
 			VI_UNLOCK(vp);
 			continue;
 		}
-		mtx_unlock(&mntvnode_mtx);
+		MNT_IUNLOCK(mp);
 		/*
 		 * Step 4: invalidate all inactive vnodes.
 		 */
@@ -614,9 +614,9 @@ ext2_reload(mountp, cred, td)
 		brelse(bp);
 		VOP_UNLOCK(vp, 0, td);
 		vrele(vp);
-		mtx_lock(&mntvnode_mtx);
+		MNT_ILOCK(mp);
 	}
-	mtx_unlock(&mntvnode_mtx);
+	MNT_IUNLOCK(mp);
 	return (0);
 }
 
@@ -901,7 +901,7 @@ ext2_sync(mp, waitfor, cred, td)
 	/*
 	 * Write back each (modified) inode.
 	 */
-	mtx_lock(&mntvnode_mtx);
+	MNT_ILOCK(mp);
 loop:
 	for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) {
 		/*
@@ -916,19 +916,19 @@ ext2_sync(mp, waitfor, cred, td)
 			VI_UNLOCK(vp);
 			continue;
 		}
-		mtx_unlock(&mntvnode_mtx);
+		MNT_IUNLOCK(mp);
 		ip = VTOI(vp);
 		if (vp->v_type == VNON ||
 		    ((ip->i_flag &
 		    (IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE)) == 0 &&
 		    (TAILQ_EMPTY(&vp->v_dirtyblkhd) || waitfor == MNT_LAZY))) {
 			VI_UNLOCK(vp);
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			continue;
 		}
 		error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, td);
 		if (error) {
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			if (error == ENOENT)
 				goto loop;
 			continue;
@@ -937,9 +937,9 @@ ext2_sync(mp, waitfor, cred, td)
 			allerror = error;
 		VOP_UNLOCK(vp, 0, td);
 		vrele(vp);
-		mtx_lock(&mntvnode_mtx);
+		MNT_ILOCK(mp);
 	}
-	mtx_unlock(&mntvnode_mtx);
+	MNT_IUNLOCK(mp);
 	/*
 	 * Force stale file system control information to be flushed.
 	 */

sys/kern/vfs_default.c

@@ -879,7 +879,7 @@ vfs_stdsync(mp, waitfor, cred, td)
 	/*
 	 * Force stale buffer cache information to be flushed.
 	 */
-	mtx_lock(&mntvnode_mtx);
+	MNT_ILOCK(mp);
 loop:
 	for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) {
 		/*
@@ -896,10 +896,10 @@ vfs_stdsync(mp, waitfor, cred, td)
 			VI_UNLOCK(vp);
 			continue;
 		}
-		mtx_unlock(&mntvnode_mtx);
+		MNT_IUNLOCK(mp);
 
 		if ((error = vget(vp, lockreq, td)) != 0) {
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			if (error == ENOENT)
 				goto loop;
 			continue;
@@ -910,9 +910,9 @@ vfs_stdsync(mp, waitfor, cred, td)
 
 		VOP_UNLOCK(vp, 0, td);
 		vrele(vp);
-		mtx_lock(&mntvnode_mtx);
+		MNT_ILOCK(mp);
 	}
-	mtx_unlock(&mntvnode_mtx);
+	MNT_IUNLOCK(mp);
 	return (allerror);
 }
 

sys/kern/vfs_mount.c

@@ -116,9 +116,6 @@ struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist);
 /* For any iteration/modification of mountlist */
 struct mtx mountlist_mtx;
 
-/* For any iteration/modification of mnt_vnodelist */
-struct mtx mntvnode_mtx;
-
 /*
  * The vnode of the system's root (/ in the filesystem, without chroot
  * active.)
@@ -662,6 +659,7 @@ vfs_nmount(td, fsflags, fsoptions)
 	TAILQ_INIT(&mp->mnt_nvnodelist);
 	TAILQ_INIT(&mp->mnt_reservedvnlist);
 	mp->mnt_nvnodelistsize = 0;
+	mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF);
 	lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, LK_NOPAUSE);
 	(void)vfs_busy(mp, LK_NOWAIT, 0, td);
 	mp->mnt_op = vfsp->vfc_vfsops;
@@ -1029,6 +1027,7 @@ vfs_mount(td, fstype, fspath, fsflags, fsdata)
 	TAILQ_INIT(&mp->mnt_nvnodelist);
 	TAILQ_INIT(&mp->mnt_reservedvnlist);
 	mp->mnt_nvnodelistsize = 0;
+	mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF);
 	lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, LK_NOPAUSE);
 	(void)vfs_busy(mp, LK_NOWAIT, 0, td);
 	mp->mnt_op = vfsp->vfc_vfsops;
@@ -1371,6 +1370,7 @@ dounmount(mp, flags, td)
 		panic("unmount: dangling vnode");
 	lockmgr(&mp->mnt_lock, LK_RELEASE | LK_INTERLOCK, &mountlist_mtx, td);
 	lockdestroy(&mp->mnt_lock);
+	mtx_destroy(&mp->mnt_mtx);
 	if (coveredvp != NULL)
 		vrele(coveredvp);
 	if (mp->mnt_kern_flag & MNTK_MWAIT)
@@ -1408,6 +1408,7 @@ vfs_rootmountalloc(fstypename, devname, mpp)
 	if (vfsp == NULL)
 		return (ENODEV);
 	mp = malloc((u_long)sizeof(struct mount), M_MOUNT, M_WAITOK | M_ZERO);
+	mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF);
 	lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, LK_NOPAUSE);
 	(void)vfs_busy(mp, LK_NOWAIT, 0, td);
 	TAILQ_INIT(&mp->mnt_nvnodelist);

sys/kern/vfs_subr.c

@@ -476,7 +476,6 @@ vntblinit(void *dummy __unused)
 	    (5 * (sizeof(struct vm_object) + sizeof(struct vnode))));
 	minvnodes = desiredvnodes / 4;
 	mtx_init(&mountlist_mtx, "mountlist", NULL, MTX_DEF);
-	mtx_init(&mntvnode_mtx, "mntvnode", NULL, MTX_DEF);
 	mtx_init(&mntid_mtx, "mntid", NULL, MTX_DEF);
 	mtx_init(&spechash_mtx, "spechash", NULL, MTX_DEF);
 	TAILQ_INIT(&vnode_free_list);
@@ -710,7 +709,7 @@ vlrureclaim(struct mount *mp)
 	trigger = cnt.v_page_count * 2 / usevnodes;
 
 	done = 0;
-	mtx_lock(&mntvnode_mtx);
+	MNT_ILOCK(mp);
 	count = mp->mnt_nvnodelistsize / 10 + 1;
 	while (count && (vp = TAILQ_FIRST(&mp->mnt_nvnodelist)) != NULL) {
 		TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
@@ -722,16 +721,16 @@ vlrureclaim(struct mount *mp)
 			if (VMIGHTFREE(vp) &&           /* critical path opt */
 			    (vp->v_object == NULL ||
 			    vp->v_object->resident_page_count < trigger)) {
-				mtx_unlock(&mntvnode_mtx);
+				MNT_IUNLOCK(mp);
 				vgonel(vp, curthread);
 				done++;
-				mtx_lock(&mntvnode_mtx);
+				MNT_ILOCK(mp);
 			} else
 				VI_UNLOCK(vp);
 		}
 		--count;
 	}
-	mtx_unlock(&mntvnode_mtx);
+	MNT_IUNLOCK(mp);
 	return done;
 }
 
@@ -1051,24 +1050,26 @@ insmntque(vp, mp)
 	register struct mount *mp;
 {
 
-	mtx_lock(&mntvnode_mtx);
 	/*
 	 * Delete from old mount point vnode list, if on one.
 	 */
 	if (vp->v_mount != NULL) {
+		MNT_ILOCK(vp->v_mount);
 		KASSERT(vp->v_mount->mnt_nvnodelistsize > 0,
 			("bad mount point vnode list size"));
 		TAILQ_REMOVE(&vp->v_mount->mnt_nvnodelist, vp, v_nmntvnodes);
 		vp->v_mount->mnt_nvnodelistsize--;
+		MNT_IUNLOCK(vp->v_mount);
 	}
 	/*
 	 * Insert into list of vnodes for the new mount point, if available.
 	 */
 	if ((vp->v_mount = mp) != NULL) {
+		MNT_ILOCK(vp->v_mount);
 		TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
 		mp->mnt_nvnodelistsize++;
+		MNT_IUNLOCK(vp->v_mount);
 	}
-	mtx_unlock(&mntvnode_mtx);
 }
 
 /*
@@ -2368,7 +2369,7 @@ vflush(mp, rootrefs, flags)
 		vput(rootvp);
 
 	}
-	mtx_lock(&mntvnode_mtx);
+	MNT_ILOCK(mp);
 loop:
 	for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp; vp = nvp) {
 		/*
@@ -2380,10 +2381,10 @@ vflush(mp, rootrefs, flags)
 		nvp = TAILQ_NEXT(vp, v_nmntvnodes);
 
 		VI_LOCK(vp);
-		mtx_unlock(&mntvnode_mtx);
+		MNT_IUNLOCK(mp);
 		error = vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE, td);
 		if (error) {
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			goto loop;
 		}
 		/*
@@ -2391,7 +2392,7 @@ vflush(mp, rootrefs, flags)
 		 */
 		if ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM)) {
 			VOP_UNLOCK(vp, 0, td);
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			continue;
 		}
 		/*
@@ -2407,7 +2408,7 @@ vflush(mp, rootrefs, flags)
 			    (error == 0 && vattr.va_nlink > 0)) &&
 			    (vp->v_writecount == 0 || vp->v_type != VREG)) {
 				VOP_UNLOCK(vp, LK_INTERLOCK, td);
-				mtx_lock(&mntvnode_mtx);
+				MNT_ILOCK(mp);
 				continue;
 			}
 		} else
@@ -2421,7 +2422,7 @@ vflush(mp, rootrefs, flags)
 		 */
 		if (vp->v_usecount == 0) {
 			vgonel(vp, td);
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			continue;
 		}
 
@@ -2435,7 +2436,7 @@ vflush(mp, rootrefs, flags)
 				vgonel(vp, td);
 			else
 				vgonechrl(vp, td);
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			continue;
 		}
 #ifdef DIAGNOSTIC
@@ -2443,10 +2444,10 @@ vflush(mp, rootrefs, flags)
 			vprint("vflush: busy vnode", vp);
 #endif
 		VI_UNLOCK(vp);
-		mtx_lock(&mntvnode_mtx);
+		MNT_ILOCK(mp);
 		busy++;
 	}
-	mtx_unlock(&mntvnode_mtx);
+	MNT_IUNLOCK(mp);
 	if (rootrefs > 0 && (flags & FORCECLOSE) == 0) {
 		/*
 		 * If just the root vnode is busy, and if its refcount
@@ -2481,10 +2482,10 @@ vlruvp(struct vnode *vp)
 	struct mount *mp;
 
 	if ((mp = vp->v_mount) != NULL) {
-		mtx_lock(&mntvnode_mtx);
+		MNT_ILOCK(mp);
 		TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
 		TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
-		mtx_unlock(&mntvnode_mtx);
+		MNT_IUNLOCK(mp);
 	}
 #endif
 }
@@ -3073,7 +3074,7 @@ sysctl_vnode(SYSCTL_HANDLER_ARGS)
 	TAILQ_FOREACH(mp, &mountlist, mnt_list) {
 		if (vfs_busy(mp, LK_NOWAIT, &mountlist_mtx, td))
 			continue;
-		mtx_lock(&mntvnode_mtx);
+		MNT_ILOCK(mp);
 		TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
 			if (n == len)
 				break;
@@ -3122,7 +3123,7 @@ sysctl_vnode(SYSCTL_HANDLER_ARGS)
 			vrele(vp);
 			++n;
 		}
-		mtx_unlock(&mntvnode_mtx);
+		MNT_IUNLOCK(mp);
 		mtx_lock(&mountlist_mtx);
 		vfs_unbusy(mp, td);
 		if (n == len)
@@ -3201,7 +3202,7 @@ vfs_msync(struct mount *mp, int flags)
 	GIANT_REQUIRED;
 
 	tries = 5;
-	mtx_lock(&mntvnode_mtx);
+	MNT_ILOCK(mp);
 loop:
 	for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) {
 		if (vp->v_mount != mp) {
@@ -3219,13 +3220,13 @@ vfs_msync(struct mount *mp, int flags)
 
 		if ((vp->v_iflag & VI_OBJDIRTY) &&
 		    (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) {
-			mtx_unlock(&mntvnode_mtx);
+			MNT_IUNLOCK(mp);
 			if (!vget(vp,
 			    LK_EXCLUSIVE | LK_RETRY | LK_INTERLOCK,
 			    curthread)) {
 				if (vp->v_vflag & VV_NOSYNC) {	/* unlinked */
 					vput(vp);
-					mtx_lock(&mntvnode_mtx);
+					MNT_ILOCK(mp);
 					continue;
 				}
 
@@ -3238,7 +3239,7 @@ vfs_msync(struct mount *mp, int flags)
 				}
 				vput(vp);
 			}
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			if (TAILQ_NEXT(vp, v_nmntvnodes) != nvp) {
 				if (--tries > 0)
 					goto loop;
@@ -3247,7 +3248,7 @@ vfs_msync(struct mount *mp, int flags)
 		} else
 			VI_UNLOCK(vp);
 	}
-	mtx_unlock(&mntvnode_mtx);
+	MNT_IUNLOCK(mp);
 }
 
 /*

sys/nfsclient/nfs_subs.c

@@ -788,7 +788,7 @@ nfs_clearcommit(struct mount *mp)
 	GIANT_REQUIRED;
 
 	s = splbio();
-	mtx_lock(&mntvnode_mtx);
+	MNT_ILOCK(mp);
 loop:
 	for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp; vp = nvp) {
 		if (vp->v_mount != mp)	/* Paranoia */
@@ -799,7 +799,7 @@ nfs_clearcommit(struct mount *mp)
 			VI_UNLOCK(vp);
 			continue;
 		}
-		mtx_unlock(&mntvnode_mtx);
+		MNT_IUNLOCK(mp);
 		for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
 			nbp = TAILQ_NEXT(bp, b_vnbufs);
 			if (BUF_REFCNT(bp) == 0 &&
@@ -808,9 +808,9 @@ nfs_clearcommit(struct mount *mp)
 				bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
 		}
 		VI_UNLOCK(vp);
-		mtx_lock(&mntvnode_mtx);
+		MNT_ILOCK(mp);
 	}
-	mtx_unlock(&mntvnode_mtx);
+	MNT_IUNLOCK(mp);
 	splx(s);
 }
 

sys/nfsclient/nfs_vfsops.c

@@ -931,7 +931,7 @@ nfs_sync(struct mount *mp, int waitfor, struct ucred *cred, struct thread *td)
 	/*
 	 * Force stale buffer cache information to be flushed.
 	 */
-	mtx_lock(&mntvnode_mtx);
+	MNT_ILOCK(mp);
 loop:
 	for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
 	     vp != NULL;
@@ -944,15 +944,15 @@ nfs_sync(struct mount *mp, int waitfor, struct ucred *cred, struct thread *td)
 			goto loop;
 		vnp = TAILQ_NEXT(vp, v_nmntvnodes);
 		VI_LOCK(vp);
-		mtx_unlock(&mntvnode_mtx);
+		MNT_IUNLOCK(mp);
 		if (VOP_ISLOCKED(vp, NULL) || TAILQ_EMPTY(&vp->v_dirtyblkhd) ||
 		    waitfor == MNT_LAZY) {
 			VI_UNLOCK(vp);
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			continue;
 		}
 		if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, td)) {
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			goto loop;
 		}
 		error = VOP_FSYNC(vp, cred, waitfor, td);
@@ -960,8 +960,9 @@ nfs_sync(struct mount *mp, int waitfor, struct ucred *cred, struct thread *td)
 			allerror = error;
 		VOP_UNLOCK(vp, 0, td);
 		vrele(vp);
-		mtx_lock(&mntvnode_mtx);
+
+		MNT_ILOCK(mp);
 	}
-	mtx_unlock(&mntvnode_mtx);
+	MNT_IUNLOCK(mp);
 	return (allerror);
 }

sys/sys/mount.h

@@ -132,6 +132,7 @@ struct mount {
 	struct vnodelst	mnt_nvnodelist;		/* list of vnodes this mount */
 	struct vnodelst	mnt_reservedvnlist;	/* (future) dirty vnode list */
 	struct lock	mnt_lock;		/* mount structure lock */
+	struct mtx	mnt_mtx;		/* mount structure interlock */
 	int		mnt_writeopcount;	/* write syscalls in progress */
 	int		mnt_flag;		/* flags shared with user */
 	struct vfsoptlist *mnt_opt;		/* current mount options */
@@ -148,6 +149,11 @@ struct mount {
 	struct label	mnt_fslabel;		/* MAC label for the fs */
 	int		mnt_nvnodelistsize;	/* # of vnodes on this mount */
 };
+
+
+#define	MNT_ILOCK(mp)	mtx_lock(&(mp)->mnt_mtx)
+#define	MNT_IUNLOCK(mp)	mtx_unlock(&(mp)->mnt_mtx)
+
 #endif /* _KERNEL */
 
 /*

sys/sys/vnode.h

@@ -464,11 +464,6 @@ struct vnodeop_desc {
  */
 extern struct vnodeop_desc *vnodeop_descs[];
 
-/*
- * Interlock for scanning list of vnodes attached to a mountpoint
- */
-extern struct mtx mntvnode_mtx;
-
 #define	VOPARG_OFFSETOF(s_type, field)	__offsetof(s_type, field)
 #define	VOPARG_OFFSETTO(s_type, s_offset, struct_p) \
     ((s_type)(((char*)(struct_p)) + (s_offset)))

sys/ufs/ffs/ffs_snapshot.c

@@ -405,7 +405,7 @@ ffs_snapshot(mp, snapfile)
 	snaplistsize = fs->fs_ncg + howmany(fs->fs_cssize, fs->fs_bsize) +
 	    FSMAXSNAP + 1 /* superblock */ + 1 /* last block */ + 1 /* size */;
 	mp->mnt_kern_flag &= ~MNTK_SUSPENDED;
-	mtx_lock(&mntvnode_mtx);
+	MNT_ILOCK(mp);
 loop:
 	for (xvp = TAILQ_FIRST(&mp->mnt_nvnodelist); xvp; xvp = nvp) {
 		/*
@@ -416,30 +416,30 @@ ffs_snapshot(mp, snapfile)
 			goto loop;
 		nvp = TAILQ_NEXT(xvp, v_nmntvnodes);
 		VI_LOCK(xvp);
-		mtx_unlock(&mntvnode_mtx);
+		MNT_IUNLOCK(mp);
 		if ((xvp->v_iflag & VI_XLOCK) ||
 		    xvp->v_usecount == 0 || xvp->v_type == VNON ||
 		    (VTOI(xvp)->i_flags & SF_SNAPSHOT)) {
 			VI_UNLOCK(xvp);
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			continue;
 		}
 		if (snapdebug)
 			vprint("ffs_snapshot: busy vnode", xvp);
 		if (vn_lock(xvp, LK_EXCLUSIVE | LK_INTERLOCK, td) != 0) {
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			goto loop;
 		}
 		if (VOP_GETATTR(xvp, &vat, td->td_ucred, td) == 0 &&
 		    vat.va_nlink > 0) {
 			VOP_UNLOCK(xvp, 0, td);
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			continue;
 		}
 		xp = VTOI(xvp);
 		if (ffs_checkfreefile(copy_fs, vp, xp->i_number)) {
 			VOP_UNLOCK(xvp, 0, td);
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			continue;
 		}
 		/*
@@ -475,9 +475,9 @@ ffs_snapshot(mp, snapfile)
 			sbp = NULL;
 			goto out1;
 		}
-		mtx_lock(&mntvnode_mtx);
+		MNT_ILOCK(mp);
 	}
-	mtx_unlock(&mntvnode_mtx);
+	MNT_IUNLOCK(mp);
 	/*
 	 * If there already exist snapshots on this filesystem, grab a
 	 * reference to their shared lock. If this is the first snapshot

sys/ufs/ffs/ffs_vfsops.c

@@ -495,10 +495,10 @@ ffs_reload(mp, cred, td)
 	}
 
 loop:
-	mtx_lock(&mntvnode_mtx);
+	MNT_ILOCK(mp);
 	for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) {
 		if (vp->v_mount != mp) {
-			mtx_unlock(&mntvnode_mtx);
+			MNT_IUNLOCK(mp);
 			goto loop;
 		}
 		nvp = TAILQ_NEXT(vp, v_nmntvnodes);
@@ -507,7 +507,7 @@ ffs_reload(mp, cred, td)
 			VI_UNLOCK(vp);
 			continue;
 		}
-		mtx_unlock(&mntvnode_mtx);
+		MNT_IUNLOCK(mp);
 		/*
 		 * Step 4: invalidate all inactive vnodes.
 		 */
@@ -540,9 +540,9 @@ ffs_reload(mp, cred, td)
 		brelse(bp);
 		VOP_UNLOCK(vp, 0, td);
 		vrele(vp);
-		mtx_lock(&mntvnode_mtx);
+		MNT_ILOCK(mp);
 	}
-	mtx_unlock(&mntvnode_mtx);
+	MNT_IUNLOCK(mp);
 	return (0);
 }
 
@@ -1130,7 +1130,7 @@ ffs_sync(mp, waitfor, cred, td)
 		lockreq = LK_EXCLUSIVE;
 	}
 	lockreq |= LK_INTERLOCK;
-	mtx_lock(&mntvnode_mtx);
+	MNT_ILOCK(mp);
 loop:
 	for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) {
 		/*
@@ -1159,9 +1159,9 @@ ffs_sync(mp, waitfor, cred, td)
 			VI_UNLOCK(vp);
 			continue;
 		}
-		mtx_unlock(&mntvnode_mtx);
+		MNT_IUNLOCK(mp);
 		if ((error = vget(vp, lockreq, td)) != 0) {
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			if (error == ENOENT)
 				goto loop;
 			continue;
@@ -1170,11 +1170,11 @@ ffs_sync(mp, waitfor, cred, td)
 			allerror = error;
 		VOP_UNLOCK(vp, 0, td);
 		vrele(vp);
-		mtx_lock(&mntvnode_mtx);
+		MNT_ILOCK(mp);
 		if (TAILQ_NEXT(vp, v_nmntvnodes) != nvp)
 			goto loop;
 	}
-	mtx_unlock(&mntvnode_mtx);
+	MNT_IUNLOCK(mp);
 	/*
 	 * Force stale filesystem control information to be flushed.
 	 */
@@ -1183,7 +1183,7 @@ ffs_sync(mp, waitfor, cred, td)
 			allerror = error;
 		/* Flushed work items may create new vnodes to clean */
 		if (allerror == 0 && count) {
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			goto loop;
 		}
 	}
@@ -1199,7 +1199,7 @@ ffs_sync(mp, waitfor, cred, td)
 			allerror = error;
 		VOP_UNLOCK(devvp, 0, td);
 		if (allerror == 0 && waitfor == MNT_WAIT) {
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			goto loop;
 		}
 	} else

sys/ufs/ufs/ufs_quota.c

@@ -455,34 +455,34 @@ quotaon(td, mp, type, fname)
 	 * adding references to quota file being opened.
 	 * NB: only need to add dquot's for inodes being modified.
 	 */
-	mtx_lock(&mntvnode_mtx);
+	MNT_ILOCK(mp);
 again:
 	for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nextvp) {
 		if (vp->v_mount != mp)
 			goto again;
 		nextvp = TAILQ_NEXT(vp, v_nmntvnodes);
 		VI_LOCK(vp);
-		mtx_unlock(&mntvnode_mtx);
+		MNT_IUNLOCK(mp);
 		if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, td)) {
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			goto again;
 		}
 		if (vp->v_type == VNON || vp->v_writecount == 0) {
 			VOP_UNLOCK(vp, 0, td);
 			vrele(vp);
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			continue;
 		}
 		error = getinoquota(VTOI(vp));
 		VOP_UNLOCK(vp, 0, td);
 		vrele(vp);
-		mtx_lock(&mntvnode_mtx);
+		MNT_ILOCK(mp);
 		if (error)
 			break;
 		if (TAILQ_NEXT(vp, v_nmntvnodes) != nextvp)
 			goto again;
 	}
-	mtx_unlock(&mntvnode_mtx);
+	MNT_IUNLOCK(mp);
 	ump->um_qflags[type] &= ~QTF_OPENING;
 	if (error)
 		quotaoff(td, mp, type);
@@ -516,7 +516,7 @@ quotaoff(td, mp, type)
 	 * Search vnodes associated with this mount point,
 	 * deleting any references to quota file being closed.
 	 */
-	mtx_lock(&mntvnode_mtx);
+	MNT_ILOCK(mp);
 again:
 	for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nextvp) {
 		if (vp->v_mount != mp)
@@ -524,14 +524,14 @@ quotaoff(td, mp, type)
 		nextvp = TAILQ_NEXT(vp, v_nmntvnodes);
 
 		VI_LOCK(vp);
-		mtx_unlock(&mntvnode_mtx);
+		MNT_IUNLOCK(mp);
 		if (vp->v_type == VNON) {
 			VI_UNLOCK(vp);
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			continue;
 		}
 		if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, td)) {
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			goto again;
 		}
 		ip = VTOI(vp);
@@ -540,11 +540,11 @@ quotaoff(td, mp, type)
 		dqrele(vp, dq);
 		VOP_UNLOCK(vp, 0, td);
 		vrele(vp);
-		mtx_lock(&mntvnode_mtx);
+		MNT_ILOCK(mp);
 		if (TAILQ_NEXT(vp, v_nmntvnodes) != nextvp)
 			goto again;
 	}
-	mtx_unlock(&mntvnode_mtx);
+	MNT_IUNLOCK(mp);
 	dqflush(qvp);
 	ASSERT_VOP_LOCKED(qvp, "quotaoff");
 	qvp->v_vflag &= ~VV_SYSTEM;
@@ -749,22 +749,22 @@ qsync(mp)
 	 * Search vnodes associated with this mount point,
 	 * synchronizing any modified dquot structures.
 	 */
-	mtx_lock(&mntvnode_mtx);
+	MNT_ILOCK(mp);
 again:
 	for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nextvp) {
 		if (vp->v_mount != mp)
 			goto again;
 		nextvp = TAILQ_NEXT(vp, v_nmntvnodes);
 		VI_LOCK(vp);
-		mtx_unlock(&mntvnode_mtx);
+		MNT_IUNLOCK(mp);
 		if (vp->v_type == VNON) {
 			VI_UNLOCK(vp);
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			continue;
 		}
 		error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, td);
 		if (error) {
-			mtx_lock(&mntvnode_mtx);
+			MNT_ILOCK(mp);
 			if (error == ENOENT)
 				goto again;
 			continue;
@@ -775,11 +775,11 @@ qsync(mp)
 				dqsync(vp, dq);
 		}
 		vput(vp);
-		mtx_lock(&mntvnode_mtx);
+		MNT_ILOCK(mp);
 		if (TAILQ_NEXT(vp, v_nmntvnodes) != nextvp)
 			goto again;
 	}
-	mtx_unlock(&mntvnode_mtx);
+	MNT_IUNLOCK(mp);
 	return (0);
 }