diff --git a/bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c b/bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c
index 7acbe64cbb..c8302e3631 100644
--- a/bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c
+++ b/bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c
@@ -565,15 +565,16 @@ zfs_read(vnode_t *vp, struct file* fp, uio_t *uio, int ioflag)
 	xuio_t		*xuio = NULL;
 #endif
 
-	// Return EISDIR when reading from a directory, as Linux does.
-	if (vp->v_type == VDIR) {
-	    return EISDIR;
-	}
-
 	ZFS_ENTER(zfsvfs);
 	ZFS_VERIFY_ZP(zp);
 	os = zfsvfs->z_os;
 
+	// Return EISDIR when reading from a directory, as Linux does.
+	if (S_ISDIR(zp->z_mode)) {
+		ZFS_EXIT(zfsvfs);
+		return EISDIR;
+	}
+
 	if (zp->z_pflags & ZFS_AV_QUARANTINED) {
 		ZFS_EXIT(zfsvfs);
 		return (EACCES);
@@ -958,8 +959,11 @@ zfs_write(vnode_t *vp, uio_t *uio, int ioflag)
 		 */
 		nbytes = MIN(n, max_blksz - P2PHASE(woff, max_blksz));
 
-		if (woff + nbytes > zp->z_size)
+		if (woff + nbytes > zp->z_size) {
+			vn_lock(vp);
 			vnode_pager_setsize(vp, woff + nbytes);
+			vn_unlock(vp);
+		}
 
 		if (abuf == NULL) {
 			tx_bytes = uio->uio_resid;
diff --git a/core/pagecache.cc b/core/pagecache.cc
index 81b7a4710d..64259fe0df 100644
--- a/core/pagecache.cc
+++ b/core/pagecache.cc
@@ -204,17 +204,12 @@ class cached_page_write : public cached_page {
     }
     int writeback()
     {
-        int error;
         struct iovec iov {_page, mmu::page_size};
         struct uio uio {&iov, 1, _key.offset, mmu::page_size, UIO_WRITE};
 
         _dirty = false;
 
-        vn_lock(_vp);
-        error = VOP_WRITE(_vp, &uio, 0);
-        vn_unlock(_vp);
-
-        return error;
+        return VOP_WRITE(_vp, &uio, 0);
     }
     void* release() { // called to demote a page from cache page to anonymous
         assert(boost::get<std::nullptr_t>(_ptes) == nullptr);
diff --git a/fs/devfs/devfs_vnops.cc b/fs/devfs/devfs_vnops.cc
index 3ad28a5630..0a88c65098 100644
--- a/fs/devfs/devfs_vnops.cc
+++ b/fs/devfs/devfs_vnops.cc
@@ -104,12 +104,14 @@ devfs_close(struct vnode *vp, struct file *fp)
 static int
 devfs_read(struct vnode *vp, struct file *fp, struct uio *uio, int ioflags)
 {
+	SCOPE_LOCK(vp->v_lock);
 	return device_read((device*)vp->v_data, uio, ioflags);
 }
 
 static int
 devfs_write(struct vnode *vp, struct uio *uio, int ioflags)
 {
+	SCOPE_LOCK(vp->v_lock);
 	return device_write((device*)vp->v_data, uio, ioflags);
 }
 
diff --git a/fs/procfs/procfs_vnops.cc b/fs/procfs/procfs_vnops.cc
index 267048fe9e..8fb39aab13 100644
--- a/fs/procfs/procfs_vnops.cc
+++ b/fs/procfs/procfs_vnops.cc
@@ -147,6 +147,7 @@ static int
 procfs_read(vnode* vp, file *fp, uio* uio, int ioflags)
 {
     auto* data = static_cast<string*>(fp->f_data);
+    SCOPE_LOCK(vp->v_lock);
 
     if (vp->v_type == VDIR)
         return EISDIR;
diff --git a/fs/ramfs/ramfs_vnops.cc b/fs/ramfs/ramfs_vnops.cc
index 5509d965c8..4c51e56b79 100644
--- a/fs/ramfs/ramfs_vnops.cc
+++ b/fs/ramfs/ramfs_vnops.cc
@@ -299,6 +299,7 @@ ramfs_read(struct vnode *vp, struct file *fp, struct uio *uio, int ioflag)
 {
 	struct ramfs_node *np = (ramfs_node*)vp->v_data;
 	size_t len;
+	SCOPE_LOCK(vp->v_lock);
 
 	if (vp->v_type == VDIR)
 		return EISDIR;
@@ -325,6 +326,7 @@ static int
 ramfs_write(struct vnode *vp, struct uio *uio, int ioflag)
 {
 	struct ramfs_node *np = (ramfs_node*)vp->v_data;
+	SCOPE_LOCK(vp->v_lock);
 
 	if (vp->v_type == VDIR)
 		return EISDIR;
diff --git a/fs/vfs/vfs_fops.cc b/fs/vfs/vfs_fops.cc
index 54a8192104..b4416c1ae7 100644
--- a/fs/vfs/vfs_fops.cc
+++ b/fs/vfs/vfs_fops.cc
@@ -47,7 +47,6 @@ int vfs_file::read(struct uio *uio, int flags)
 
 	bytes = uio->uio_resid;
 
-	vn_lock(vp);
 	if ((flags & FOF_OFFSET) == 0)
 		uio->uio_offset = fp->f_offset;
 
@@ -57,7 +56,6 @@ int vfs_file::read(struct uio *uio, int flags)
 		if ((flags & FOF_OFFSET) == 0)
 			fp->f_offset += count;
 	}
-	vn_unlock(vp);
 
 	return error;
 }
@@ -74,8 +72,6 @@ int vfs_file::write(struct uio *uio, int flags)
 
 	bytes = uio->uio_resid;
 
-	vn_lock(vp);
-
 	if (fp->f_flags & O_APPEND)
 		ioflags |= IO_APPEND;
 	if (fp->f_flags & (O_DSYNC|O_SYNC))
@@ -91,7 +87,6 @@ int vfs_file::write(struct uio *uio, int flags)
 			fp->f_offset += count;
 	}
 
-	vn_unlock(vp);
 	return error;
 }
 
@@ -171,9 +166,7 @@ int vfs_file::get_arcbuf(void* key, off_t offset)
     data.uio_resid = mmu::page_size;
     data.uio_rw = UIO_READ;
 
-    vn_lock(vp);
     assert(VOP_CACHE(vp, this, &data) == 0);
-    vn_unlock(vp);
 
     return (data.uio_resid != 0) ? -1 : 0;
 }