diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 8c3dbe1..09e4d8a 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -163,7 +163,6 @@
 {
 	const char     		*cp = name, *next;
 	struct proc_dir_entry	*de;
-	unsigned int		len;
 
 	de = *ret;
 	if (!de)
@@ -174,13 +173,12 @@
 		if (!next)
 			break;
 
-		len = next - cp;
-		de = pde_subdir_find(de, cp, len);
+		de = pde_subdir_find(de, cp, next - cp);
 		if (!de) {
 			WARN(1, "name '%s'\n", name);
 			return -ENOENT;
 		}
-		cp += len + 1;
+		cp = next + 1;
 	}
 	*residual = cp;
 	*ret = de;
@@ -271,6 +269,11 @@
 struct dentry *proc_lookup(struct inode *dir, struct dentry *dentry,
 		unsigned int flags)
 {
+	struct proc_fs_info *fs_info = proc_sb_info(dir->i_sb);
+
+	if (fs_info->pidonly == PROC_PIDONLY_ON)
+		return ERR_PTR(-ENOENT);
+
 	return proc_lookup_de(dir, dentry, PDE(dir));
 }
 
@@ -327,6 +330,10 @@
 int proc_readdir(struct file *file, struct dir_context *ctx)
 {
 	struct inode *inode = file_inode(file);
+	struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
+
+	if (fs_info->pidonly == PROC_PIDONLY_ON)
+		return 1;
 
 	return proc_readdir_de(file, ctx, PDE(inode));
 }
@@ -485,7 +492,7 @@
 	ent = __proc_create(&parent, name, S_IFDIR | mode, 2);
 	if (ent) {
 		ent->data = data;
-		ent->proc_fops = &proc_dir_operations;
+		ent->proc_dir_ops = &proc_dir_operations;
 		ent->proc_iops = &proc_dir_inode_operations;
 		if (force_lookup) {
 			pde_force_lookup(ent);
@@ -525,7 +532,7 @@
 	ent = __proc_create(&parent, name, mode, 2);
 	if (ent) {
 		ent->data = NULL;
-		ent->proc_fops = NULL;
+		ent->proc_dir_ops = NULL;
 		ent->proc_iops = NULL;
 		ent = proc_register(parent, ent);
 	}
@@ -553,27 +560,32 @@
 	return p;
 }
 
+static inline void pde_set_flags(struct proc_dir_entry *pde)
+{
+	if (pde->proc_ops->proc_flags & PROC_ENTRY_PERMANENT)
+		pde->flags |= PROC_ENTRY_PERMANENT;
+}
+
 struct proc_dir_entry *proc_create_data(const char *name, umode_t mode,
 		struct proc_dir_entry *parent,
-		const struct file_operations *proc_fops, void *data)
+		const struct proc_ops *proc_ops, void *data)
 {
 	struct proc_dir_entry *p;
 
-	BUG_ON(proc_fops == NULL);
-
 	p = proc_create_reg(name, mode, &parent, data);
 	if (!p)
 		return NULL;
-	p->proc_fops = proc_fops;
+	p->proc_ops = proc_ops;
+	pde_set_flags(p);
 	return proc_register(parent, p);
 }
 EXPORT_SYMBOL(proc_create_data);
  
 struct proc_dir_entry *proc_create(const char *name, umode_t mode,
 				   struct proc_dir_entry *parent,
-				   const struct file_operations *proc_fops)
+				   const struct proc_ops *proc_ops)
 {
-	return proc_create_data(name, mode, parent, proc_fops, NULL);
+	return proc_create_data(name, mode, parent, proc_ops, NULL);
 }
 EXPORT_SYMBOL(proc_create);
 
@@ -595,11 +607,12 @@
 	return seq_release(inode, file);
 }
 
-static const struct file_operations proc_seq_fops = {
-	.open		= proc_seq_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= proc_seq_release,
+static const struct proc_ops proc_seq_ops = {
+	/* not permanent -- can call into arbitrary seq_operations */
+	.proc_open	= proc_seq_open,
+	.proc_read_iter	= seq_read_iter,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= proc_seq_release,
 };
 
 struct proc_dir_entry *proc_create_seq_private(const char *name, umode_t mode,
@@ -611,7 +624,7 @@
 	p = proc_create_reg(name, mode, &parent, data);
 	if (!p)
 		return NULL;
-	p->proc_fops = &proc_seq_fops;
+	p->proc_ops = &proc_seq_ops;
 	p->seq_ops = ops;
 	p->state_size = state_size;
 	return proc_register(parent, p);
@@ -625,11 +638,12 @@
 	return single_open(file, de->single_show, de->data);
 }
 
-static const struct file_operations proc_single_fops = {
-	.open		= proc_single_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
+static const struct proc_ops proc_single_ops = {
+	/* not permanent -- can call into arbitrary ->single_show */
+	.proc_open	= proc_single_open,
+	.proc_read_iter = seq_read_iter,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= single_release,
 };
 
 struct proc_dir_entry *proc_create_single_data(const char *name, umode_t mode,
@@ -641,7 +655,7 @@
 	p = proc_create_reg(name, mode, &parent, data);
 	if (!p)
 		return NULL;
-	p->proc_fops = &proc_single_fops;
+	p->proc_ops = &proc_single_ops;
 	p->single_show = show;
 	return proc_register(parent, p);
 }
@@ -686,9 +700,13 @@
 
 	de = pde_subdir_find(parent, fn, len);
 	if (de) {
-		rb_erase(&de->subdir_node, &parent->subdir);
-		if (S_ISDIR(de->mode)) {
-			parent->nlink--;
+		if (unlikely(pde_is_permanent(de))) {
+			WARN(1, "removing permanent /proc entry '%s'", de->name);
+			de = NULL;
+		} else {
+			rb_erase(&de->subdir_node, &parent->subdir);
+			if (S_ISDIR(de->mode))
+				parent->nlink--;
 		}
 	}
 	write_unlock(&proc_subdir_lock);
@@ -724,12 +742,24 @@
 		write_unlock(&proc_subdir_lock);
 		return -ENOENT;
 	}
+	if (unlikely(pde_is_permanent(root))) {
+		write_unlock(&proc_subdir_lock);
+		WARN(1, "removing permanent /proc entry '%s/%s'",
+			root->parent->name, root->name);
+		return -EINVAL;
+	}
 	rb_erase(&root->subdir_node, &parent->subdir);
 
 	de = root;
 	while (1) {
 		next = pde_subdir_first(de);
 		if (next) {
+			if (unlikely(pde_is_permanent(next))) {
+				write_unlock(&proc_subdir_lock);
+				WARN(1, "removing permanent /proc entry '%s/%s'",
+					next->parent->name, next->name);
+				return -EINVAL;
+			}
 			rb_erase(&next->subdir_node, &de->subdir);
 			de = next;
 			continue;