1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * net/sunrpc/rpc_pipe.c
   4 *
   5 * Userland/kernel interface for rpcauth_gss.
   6 * Code shamelessly plagiarized from fs/nfsd/nfsctl.c
   7 * and fs/sysfs/inode.c
   8 *
   9 * Copyright (c) 2002, Trond Myklebust <trond.myklebust@fys.uio.no>
  10 *
  11 */
  12#include <linux/module.h>
  13#include <linux/slab.h>
  14#include <linux/string.h>
  15#include <linux/pagemap.h>
  16#include <linux/mount.h>
  17#include <linux/fs_context.h>
  18#include <linux/namei.h>
  19#include <linux/fsnotify.h>
  20#include <linux/kernel.h>
  21#include <linux/rcupdate.h>
  22#include <linux/utsname.h>
  23
  24#include <asm/ioctls.h>
  25#include <linux/poll.h>
  26#include <linux/wait.h>
  27#include <linux/seq_file.h>
  28
  29#include <linux/sunrpc/clnt.h>
  30#include <linux/workqueue.h>
  31#include <linux/sunrpc/rpc_pipe_fs.h>
  32#include <linux/sunrpc/cache.h>
  33#include <linux/nsproxy.h>
  34#include <linux/notifier.h>
  35
  36#include "netns.h"
  37#include "sunrpc.h"
  38
  39#define RPCDBG_FACILITY RPCDBG_DEBUG
  40
  41#define NET_NAME(net)	((net == &init_net) ? " (init_net)" : "")
  42
  43static struct file_system_type rpc_pipe_fs_type;
  44static const struct rpc_pipe_ops gssd_dummy_pipe_ops;
  45
  46static struct kmem_cache *rpc_inode_cachep __read_mostly;
  47
  48#define RPC_UPCALL_TIMEOUT (30*HZ)
  49
  50static BLOCKING_NOTIFIER_HEAD(rpc_pipefs_notifier_list);
  51
  52int rpc_pipefs_notifier_register(struct notifier_block *nb)
  53{
  54	return blocking_notifier_chain_cond_register(&rpc_pipefs_notifier_list, nb);
  55}
  56EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_register);
  57
  58void rpc_pipefs_notifier_unregister(struct notifier_block *nb)
  59{
  60	blocking_notifier_chain_unregister(&rpc_pipefs_notifier_list, nb);
  61}
  62EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_unregister);
  63
  64static void rpc_purge_list(wait_queue_head_t *waitq, struct list_head *head,
  65		void (*destroy_msg)(struct rpc_pipe_msg *), int err)
  66{
  67	struct rpc_pipe_msg *msg;
  68
  69	if (list_empty(head))
  70		return;
  71	do {
  72		msg = list_entry(head->next, struct rpc_pipe_msg, list);
  73		list_del_init(&msg->list);
  74		msg->errno = err;
  75		destroy_msg(msg);
  76	} while (!list_empty(head));
  77
  78	if (waitq)
  79		wake_up(waitq);
  80}
  81
  82static void
  83rpc_timeout_upcall_queue(struct work_struct *work)
  84{
  85	LIST_HEAD(free_list);
  86	struct rpc_pipe *pipe =
  87		container_of(work, struct rpc_pipe, queue_timeout.work);
  88	void (*destroy_msg)(struct rpc_pipe_msg *);
  89	struct dentry *dentry;
  90
  91	spin_lock(&pipe->lock);
  92	destroy_msg = pipe->ops->destroy_msg;
  93	if (pipe->nreaders == 0) {
  94		list_splice_init(&pipe->pipe, &free_list);
  95		pipe->pipelen = 0;
  96	}
  97	dentry = dget(pipe->dentry);
  98	spin_unlock(&pipe->lock);
  99	rpc_purge_list(dentry ? &RPC_I(d_inode(dentry))->waitq : NULL,
 100			&free_list, destroy_msg, -ETIMEDOUT);
 101	dput(dentry);
 102}
 103
 104ssize_t rpc_pipe_generic_upcall(struct file *filp, struct rpc_pipe_msg *msg,
 105				char __user *dst, size_t buflen)
 106{
 107	char *data = (char *)msg->data + msg->copied;
 108	size_t mlen = min(msg->len - msg->copied, buflen);
 109	unsigned long left;
 110
 111	left = copy_to_user(dst, data, mlen);
 112	if (left == mlen) {
 113		msg->errno = -EFAULT;
 114		return -EFAULT;
 115	}
 116
 117	mlen -= left;
 118	msg->copied += mlen;
 119	msg->errno = 0;
 120	return mlen;
 121}
 122EXPORT_SYMBOL_GPL(rpc_pipe_generic_upcall);
 123
 124/**
 125 * rpc_queue_upcall - queue an upcall message to userspace
 126 * @pipe: upcall pipe on which to queue given message
 127 * @msg: message to queue
 128 *
 129 * Call with an @inode created by rpc_mkpipe() to queue an upcall.
 130 * A userspace process may then later read the upcall by performing a
 131 * read on an open file for this inode.  It is up to the caller to
 132 * initialize the fields of @msg (other than @msg->list) appropriately.
 133 */
 134int
 135rpc_queue_upcall(struct rpc_pipe *pipe, struct rpc_pipe_msg *msg)
 136{
 137	int res = -EPIPE;
 138	struct dentry *dentry;
 139
 140	spin_lock(&pipe->lock);
 141	if (pipe->nreaders) {
 142		list_add_tail(&msg->list, &pipe->pipe);
 143		pipe->pipelen += msg->len;
 144		res = 0;
 145	} else if (pipe->flags & RPC_PIPE_WAIT_FOR_OPEN) {
 146		if (list_empty(&pipe->pipe))
 147			queue_delayed_work(rpciod_workqueue,
 148					&pipe->queue_timeout,
 149					RPC_UPCALL_TIMEOUT);
 150		list_add_tail(&msg->list, &pipe->pipe);
 151		pipe->pipelen += msg->len;
 152		res = 0;
 153	}
 154	dentry = dget(pipe->dentry);
 155	spin_unlock(&pipe->lock);
 156	if (dentry) {
 157		wake_up(&RPC_I(d_inode(dentry))->waitq);
 158		dput(dentry);
 159	}
 160	return res;
 161}
 162EXPORT_SYMBOL_GPL(rpc_queue_upcall);
 163
 164static inline void
 165rpc_inode_setowner(struct inode *inode, void *private)
 166{
 167	RPC_I(inode)->private = private;
 168}
 169
 170static void
 171rpc_close_pipes(struct inode *inode)
 172{
 173	struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 174	int need_release;
 175	LIST_HEAD(free_list);
 176
 177	inode_lock(inode);
 178	spin_lock(&pipe->lock);
 179	need_release = pipe->nreaders != 0 || pipe->nwriters != 0;
 180	pipe->nreaders = 0;
 181	list_splice_init(&pipe->in_upcall, &free_list);
 182	list_splice_init(&pipe->pipe, &free_list);
 183	pipe->pipelen = 0;
 184	pipe->dentry = NULL;
 185	spin_unlock(&pipe->lock);
 186	rpc_purge_list(&RPC_I(inode)->waitq, &free_list, pipe->ops->destroy_msg, -EPIPE);
 187	pipe->nwriters = 0;
 188	if (need_release && pipe->ops->release_pipe)
 189		pipe->ops->release_pipe(inode);
 190	cancel_delayed_work_sync(&pipe->queue_timeout);
 191	rpc_inode_setowner(inode, NULL);
 192	RPC_I(inode)->pipe = NULL;
 193	inode_unlock(inode);
 194}
 195
 196static struct inode *
 197rpc_alloc_inode(struct super_block *sb)
 198{
 199	struct rpc_inode *rpci;
 200	rpci = kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL);
 201	if (!rpci)
 202		return NULL;
 203	return &rpci->vfs_inode;
 204}
 205
 206static void
 207rpc_free_inode(struct inode *inode)
 208{
 209	kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
 210}
 211
 212static int
 213rpc_pipe_open(struct inode *inode, struct file *filp)
 214{
 215	struct rpc_pipe *pipe;
 216	int first_open;
 217	int res = -ENXIO;
 218
 219	inode_lock(inode);
 220	pipe = RPC_I(inode)->pipe;
 221	if (pipe == NULL)
 222		goto out;
 223	first_open = pipe->nreaders == 0 && pipe->nwriters == 0;
 224	if (first_open && pipe->ops->open_pipe) {
 225		res = pipe->ops->open_pipe(inode);
 226		if (res)
 227			goto out;
 228	}
 229	if (filp->f_mode & FMODE_READ)
 230		pipe->nreaders++;
 231	if (filp->f_mode & FMODE_WRITE)
 232		pipe->nwriters++;
 233	res = 0;
 234out:
 235	inode_unlock(inode);
 236	return res;
 237}
 238
 239static int
 240rpc_pipe_release(struct inode *inode, struct file *filp)
 241{
 242	struct rpc_pipe *pipe;
 243	struct rpc_pipe_msg *msg;
 244	int last_close;
 245
 246	inode_lock(inode);
 247	pipe = RPC_I(inode)->pipe;
 248	if (pipe == NULL)
 249		goto out;
 250	msg = filp->private_data;
 251	if (msg != NULL) {
 252		spin_lock(&pipe->lock);
 253		msg->errno = -EAGAIN;
 254		list_del_init(&msg->list);
 255		spin_unlock(&pipe->lock);
 256		pipe->ops->destroy_msg(msg);
 257	}
 258	if (filp->f_mode & FMODE_WRITE)
 259		pipe->nwriters --;
 260	if (filp->f_mode & FMODE_READ) {
 261		pipe->nreaders --;
 262		if (pipe->nreaders == 0) {
 263			LIST_HEAD(free_list);
 264			spin_lock(&pipe->lock);
 265			list_splice_init(&pipe->pipe, &free_list);
 266			pipe->pipelen = 0;
 267			spin_unlock(&pipe->lock);
 268			rpc_purge_list(&RPC_I(inode)->waitq, &free_list,
 269					pipe->ops->destroy_msg, -EAGAIN);
 270		}
 271	}
 272	last_close = pipe->nwriters == 0 && pipe->nreaders == 0;
 273	if (last_close && pipe->ops->release_pipe)
 274		pipe->ops->release_pipe(inode);
 275out:
 276	inode_unlock(inode);
 277	return 0;
 278}
 279
 280static ssize_t
 281rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
 282{
 283	struct inode *inode = file_inode(filp);
 284	struct rpc_pipe *pipe;
 285	struct rpc_pipe_msg *msg;
 286	int res = 0;
 287
 288	inode_lock(inode);
 289	pipe = RPC_I(inode)->pipe;
 290	if (pipe == NULL) {
 291		res = -EPIPE;
 292		goto out_unlock;
 293	}
 294	msg = filp->private_data;
 295	if (msg == NULL) {
 296		spin_lock(&pipe->lock);
 297		if (!list_empty(&pipe->pipe)) {
 298			msg = list_entry(pipe->pipe.next,
 299					struct rpc_pipe_msg,
 300					list);
 301			list_move(&msg->list, &pipe->in_upcall);
 302			pipe->pipelen -= msg->len;
 303			filp->private_data = msg;
 304			msg->copied = 0;
 305		}
 306		spin_unlock(&pipe->lock);
 307		if (msg == NULL)
 308			goto out_unlock;
 309	}
 310	/* NOTE: it is up to the callback to update msg->copied */
 311	res = pipe->ops->upcall(filp, msg, buf, len);
 312	if (res < 0 || msg->len == msg->copied) {
 313		filp->private_data = NULL;
 314		spin_lock(&pipe->lock);
 315		list_del_init(&msg->list);
 316		spin_unlock(&pipe->lock);
 317		pipe->ops->destroy_msg(msg);
 318	}
 319out_unlock:
 320	inode_unlock(inode);
 321	return res;
 322}
 323
 324static ssize_t
 325rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
 326{
 327	struct inode *inode = file_inode(filp);
 328	int res;
 329
 330	inode_lock(inode);
 331	res = -EPIPE;
 332	if (RPC_I(inode)->pipe != NULL)
 333		res = RPC_I(inode)->pipe->ops->downcall(filp, buf, len);
 334	inode_unlock(inode);
 335	return res;
 336}
 337
 338static __poll_t
 339rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
 340{
 341	struct inode *inode = file_inode(filp);
 342	struct rpc_inode *rpci = RPC_I(inode);
 343	__poll_t mask = EPOLLOUT | EPOLLWRNORM;
 344
 345	poll_wait(filp, &rpci->waitq, wait);
 346
 347	inode_lock(inode);
 348	if (rpci->pipe == NULL)
 349		mask |= EPOLLERR | EPOLLHUP;
 350	else if (filp->private_data || !list_empty(&rpci->pipe->pipe))
 351		mask |= EPOLLIN | EPOLLRDNORM;
 352	inode_unlock(inode);
 353	return mask;
 354}
 355
 356static long
 357rpc_pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 358{
 359	struct inode *inode = file_inode(filp);
 360	struct rpc_pipe *pipe;
 361	int len;
 362
 363	switch (cmd) {
 364	case FIONREAD:
 365		inode_lock(inode);
 366		pipe = RPC_I(inode)->pipe;
 367		if (pipe == NULL) {
 368			inode_unlock(inode);
 369			return -EPIPE;
 370		}
 371		spin_lock(&pipe->lock);
 372		len = pipe->pipelen;
 373		if (filp->private_data) {
 374			struct rpc_pipe_msg *msg;
 375			msg = filp->private_data;
 376			len += msg->len - msg->copied;
 377		}
 378		spin_unlock(&pipe->lock);
 379		inode_unlock(inode);
 380		return put_user(len, (int __user *)arg);
 381	default:
 382		return -EINVAL;
 383	}
 384}
 385
 386static const struct file_operations rpc_pipe_fops = {
 387	.owner		= THIS_MODULE,
 388	.llseek		= no_llseek,
 389	.read		= rpc_pipe_read,
 390	.write		= rpc_pipe_write,
 391	.poll		= rpc_pipe_poll,
 392	.unlocked_ioctl	= rpc_pipe_ioctl,
 393	.open		= rpc_pipe_open,
 394	.release	= rpc_pipe_release,
 395};
 396
 397static int
 398rpc_show_info(struct seq_file *m, void *v)
 399{
 400	struct rpc_clnt *clnt = m->private;
 401
 402	rcu_read_lock();
 403	seq_printf(m, "RPC server: %s\n",
 404			rcu_dereference(clnt->cl_xprt)->servername);
 405	seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_program->name,
 406			clnt->cl_prog, clnt->cl_vers);
 407	seq_printf(m, "address: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
 408	seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO));
 409	seq_printf(m, "port: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PORT));
 410	rcu_read_unlock();
 411	return 0;
 412}
 413
 414static int
 415rpc_info_open(struct inode *inode, struct file *file)
 416{
 417	struct rpc_clnt *clnt = NULL;
 418	int ret = single_open(file, rpc_show_info, NULL);
 419
 420	if (!ret) {
 421		struct seq_file *m = file->private_data;
 422
 423		spin_lock(&file->f_path.dentry->d_lock);
 424		if (!d_unhashed(file->f_path.dentry))
 425			clnt = RPC_I(inode)->private;
 426		if (clnt != NULL && atomic_inc_not_zero(&clnt->cl_count)) {
 427			spin_unlock(&file->f_path.dentry->d_lock);
 428			m->private = clnt;
 429		} else {
 430			spin_unlock(&file->f_path.dentry->d_lock);
 431			single_release(inode, file);
 432			ret = -EINVAL;
 433		}
 434	}
 435	return ret;
 436}
 437
 438static int
 439rpc_info_release(struct inode *inode, struct file *file)
 440{
 441	struct seq_file *m = file->private_data;
 442	struct rpc_clnt *clnt = (struct rpc_clnt *)m->private;
 443
 444	if (clnt)
 445		rpc_release_client(clnt);
 446	return single_release(inode, file);
 447}
 448
 449static const struct file_operations rpc_info_operations = {
 450	.owner		= THIS_MODULE,
 451	.open		= rpc_info_open,
 452	.read		= seq_read,
 453	.llseek		= seq_lseek,
 454	.release	= rpc_info_release,
 455};
 456
 457
 458/*
 459 * Description of fs contents.
 460 */
 461struct rpc_filelist {
 462	const char *name;
 463	const struct file_operations *i_fop;
 464	umode_t mode;
 465};
 466
 467static struct inode *
 468rpc_get_inode(struct super_block *sb, umode_t mode)
 469{
 470	struct inode *inode = new_inode(sb);
 471	if (!inode)
 472		return NULL;
 473	inode->i_ino = get_next_ino();
 474	inode->i_mode = mode;
 475	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
 476	switch (mode & S_IFMT) {
 477	case S_IFDIR:
 478		inode->i_fop = &simple_dir_operations;
 479		inode->i_op = &simple_dir_inode_operations;
 480		inc_nlink(inode);
 
 481	default:
 482		break;
 483	}
 484	return inode;
 485}
 486
 487static int __rpc_create_common(struct inode *dir, struct dentry *dentry,
 488			       umode_t mode,
 489			       const struct file_operations *i_fop,
 490			       void *private)
 491{
 492	struct inode *inode;
 493
 494	d_drop(dentry);
 495	inode = rpc_get_inode(dir->i_sb, mode);
 496	if (!inode)
 497		goto out_err;
 498	inode->i_ino = iunique(dir->i_sb, 100);
 499	if (i_fop)
 500		inode->i_fop = i_fop;
 501	if (private)
 502		rpc_inode_setowner(inode, private);
 503	d_add(dentry, inode);
 504	return 0;
 505out_err:
 506	printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %pd\n",
 507			__FILE__, __func__, dentry);
 508	dput(dentry);
 509	return -ENOMEM;
 510}
 511
 512static int __rpc_create(struct inode *dir, struct dentry *dentry,
 513			umode_t mode,
 514			const struct file_operations *i_fop,
 515			void *private)
 516{
 517	int err;
 518
 519	err = __rpc_create_common(dir, dentry, S_IFREG | mode, i_fop, private);
 520	if (err)
 521		return err;
 522	fsnotify_create(dir, dentry);
 523	return 0;
 524}
 525
 526static int __rpc_mkdir(struct inode *dir, struct dentry *dentry,
 527		       umode_t mode,
 528		       const struct file_operations *i_fop,
 529		       void *private)
 530{
 531	int err;
 532
 533	err = __rpc_create_common(dir, dentry, S_IFDIR | mode, i_fop, private);
 534	if (err)
 535		return err;
 536	inc_nlink(dir);
 537	fsnotify_mkdir(dir, dentry);
 538	return 0;
 539}
 540
 541static void
 542init_pipe(struct rpc_pipe *pipe)
 543{
 544	pipe->nreaders = 0;
 545	pipe->nwriters = 0;
 546	INIT_LIST_HEAD(&pipe->in_upcall);
 547	INIT_LIST_HEAD(&pipe->in_downcall);
 548	INIT_LIST_HEAD(&pipe->pipe);
 549	pipe->pipelen = 0;
 550	INIT_DELAYED_WORK(&pipe->queue_timeout,
 551			    rpc_timeout_upcall_queue);
 552	pipe->ops = NULL;
 553	spin_lock_init(&pipe->lock);
 554	pipe->dentry = NULL;
 555}
 556
 557void rpc_destroy_pipe_data(struct rpc_pipe *pipe)
 558{
 559	kfree(pipe);
 560}
 561EXPORT_SYMBOL_GPL(rpc_destroy_pipe_data);
 562
 563struct rpc_pipe *rpc_mkpipe_data(const struct rpc_pipe_ops *ops, int flags)
 564{
 565	struct rpc_pipe *pipe;
 566
 567	pipe = kzalloc(sizeof(struct rpc_pipe), GFP_KERNEL);
 568	if (!pipe)
 569		return ERR_PTR(-ENOMEM);
 570	init_pipe(pipe);
 571	pipe->ops = ops;
 572	pipe->flags = flags;
 573	return pipe;
 574}
 575EXPORT_SYMBOL_GPL(rpc_mkpipe_data);
 576
 577static int __rpc_mkpipe_dentry(struct inode *dir, struct dentry *dentry,
 578			       umode_t mode,
 579			       const struct file_operations *i_fop,
 580			       void *private,
 581			       struct rpc_pipe *pipe)
 582{
 583	struct rpc_inode *rpci;
 584	int err;
 585
 586	err = __rpc_create_common(dir, dentry, S_IFIFO | mode, i_fop, private);
 587	if (err)
 588		return err;
 589	rpci = RPC_I(d_inode(dentry));
 590	rpci->private = private;
 591	rpci->pipe = pipe;
 592	fsnotify_create(dir, dentry);
 593	return 0;
 594}
 595
 596static int __rpc_rmdir(struct inode *dir, struct dentry *dentry)
 597{
 598	int ret;
 599
 600	dget(dentry);
 601	ret = simple_rmdir(dir, dentry);
 
 602	if (!ret)
 603		fsnotify_rmdir(dir, dentry);
 604	d_delete(dentry);
 605	dput(dentry);
 606	return ret;
 607}
 608
 609static int __rpc_unlink(struct inode *dir, struct dentry *dentry)
 610{
 611	int ret;
 612
 613	dget(dentry);
 614	ret = simple_unlink(dir, dentry);
 
 615	if (!ret)
 616		fsnotify_unlink(dir, dentry);
 617	d_delete(dentry);
 618	dput(dentry);
 619	return ret;
 620}
 621
 622static int __rpc_rmpipe(struct inode *dir, struct dentry *dentry)
 623{
 624	struct inode *inode = d_inode(dentry);
 625
 626	rpc_close_pipes(inode);
 627	return __rpc_unlink(dir, dentry);
 628}
 629
 630static struct dentry *__rpc_lookup_create_exclusive(struct dentry *parent,
 631					  const char *name)
 632{
 633	struct qstr q = QSTR_INIT(name, strlen(name));
 634	struct dentry *dentry = d_hash_and_lookup(parent, &q);
 635	if (!dentry) {
 636		dentry = d_alloc(parent, &q);
 637		if (!dentry)
 638			return ERR_PTR(-ENOMEM);
 639	}
 640	if (d_really_is_negative(dentry))
 641		return dentry;
 642	dput(dentry);
 643	return ERR_PTR(-EEXIST);
 644}
 645
 646/*
 647 * FIXME: This probably has races.
 648 */
 649static void __rpc_depopulate(struct dentry *parent,
 650			     const struct rpc_filelist *files,
 651			     int start, int eof)
 652{
 653	struct inode *dir = d_inode(parent);
 654	struct dentry *dentry;
 655	struct qstr name;
 656	int i;
 657
 658	for (i = start; i < eof; i++) {
 659		name.name = files[i].name;
 660		name.len = strlen(files[i].name);
 661		dentry = d_hash_and_lookup(parent, &name);
 662
 663		if (dentry == NULL)
 664			continue;
 665		if (d_really_is_negative(dentry))
 666			goto next;
 667		switch (d_inode(dentry)->i_mode & S_IFMT) {
 668			default:
 669				BUG();
 670			case S_IFREG:
 671				__rpc_unlink(dir, dentry);
 672				break;
 673			case S_IFDIR:
 674				__rpc_rmdir(dir, dentry);
 675		}
 676next:
 677		dput(dentry);
 678	}
 679}
 680
 681static void rpc_depopulate(struct dentry *parent,
 682			   const struct rpc_filelist *files,
 683			   int start, int eof)
 684{
 685	struct inode *dir = d_inode(parent);
 686
 687	inode_lock_nested(dir, I_MUTEX_CHILD);
 688	__rpc_depopulate(parent, files, start, eof);
 689	inode_unlock(dir);
 690}
 691
 692static int rpc_populate(struct dentry *parent,
 693			const struct rpc_filelist *files,
 694			int start, int eof,
 695			void *private)
 696{
 697	struct inode *dir = d_inode(parent);
 698	struct dentry *dentry;
 699	int i, err;
 700
 701	inode_lock(dir);
 702	for (i = start; i < eof; i++) {
 703		dentry = __rpc_lookup_create_exclusive(parent, files[i].name);
 704		err = PTR_ERR(dentry);
 705		if (IS_ERR(dentry))
 706			goto out_bad;
 707		switch (files[i].mode & S_IFMT) {
 708			default:
 709				BUG();
 710			case S_IFREG:
 711				err = __rpc_create(dir, dentry,
 712						files[i].mode,
 713						files[i].i_fop,
 714						private);
 715				break;
 716			case S_IFDIR:
 717				err = __rpc_mkdir(dir, dentry,
 718						files[i].mode,
 719						NULL,
 720						private);
 721		}
 722		if (err != 0)
 723			goto out_bad;
 724	}
 725	inode_unlock(dir);
 726	return 0;
 727out_bad:
 728	__rpc_depopulate(parent, files, start, eof);
 729	inode_unlock(dir);
 730	printk(KERN_WARNING "%s: %s failed to populate directory %pd\n",
 731			__FILE__, __func__, parent);
 732	return err;
 733}
 734
 735static struct dentry *rpc_mkdir_populate(struct dentry *parent,
 736		const char *name, umode_t mode, void *private,
 737		int (*populate)(struct dentry *, void *), void *args_populate)
 738{
 739	struct dentry *dentry;
 740	struct inode *dir = d_inode(parent);
 741	int error;
 742
 743	inode_lock_nested(dir, I_MUTEX_PARENT);
 744	dentry = __rpc_lookup_create_exclusive(parent, name);
 745	if (IS_ERR(dentry))
 746		goto out;
 747	error = __rpc_mkdir(dir, dentry, mode, NULL, private);
 748	if (error != 0)
 749		goto out_err;
 750	if (populate != NULL) {
 751		error = populate(dentry, args_populate);
 752		if (error)
 753			goto err_rmdir;
 754	}
 755out:
 756	inode_unlock(dir);
 757	return dentry;
 758err_rmdir:
 759	__rpc_rmdir(dir, dentry);
 760out_err:
 761	dentry = ERR_PTR(error);
 762	goto out;
 763}
 764
 765static int rpc_rmdir_depopulate(struct dentry *dentry,
 766		void (*depopulate)(struct dentry *))
 767{
 768	struct dentry *parent;
 769	struct inode *dir;
 770	int error;
 771
 772	parent = dget_parent(dentry);
 773	dir = d_inode(parent);
 774	inode_lock_nested(dir, I_MUTEX_PARENT);
 775	if (depopulate != NULL)
 776		depopulate(dentry);
 777	error = __rpc_rmdir(dir, dentry);
 778	inode_unlock(dir);
 779	dput(parent);
 780	return error;
 781}
 782
 783/**
 784 * rpc_mkpipe - make an rpc_pipefs file for kernel<->userspace communication
 
 785 * @parent: dentry of directory to create new "pipe" in
 786 * @name: name of pipe
 787 * @private: private data to associate with the pipe, for the caller's use
 788 * @pipe: &rpc_pipe containing input parameters
 789 *
 790 * Data is made available for userspace to read by calls to
 791 * rpc_queue_upcall().  The actual reads will result in calls to
 792 * @ops->upcall, which will be called with the file pointer,
 793 * message, and userspace buffer to copy to.
 794 *
 795 * Writes can come at any time, and do not necessarily have to be
 796 * responses to upcalls.  They will result in calls to @msg->downcall.
 797 *
 798 * The @private argument passed here will be available to all these methods
 799 * from the file pointer, via RPC_I(file_inode(file))->private.
 800 */
 801struct dentry *rpc_mkpipe_dentry(struct dentry *parent, const char *name,
 802				 void *private, struct rpc_pipe *pipe)
 803{
 804	struct dentry *dentry;
 805	struct inode *dir = d_inode(parent);
 806	umode_t umode = S_IFIFO | 0600;
 807	int err;
 808
 809	if (pipe->ops->upcall == NULL)
 810		umode &= ~0444;
 811	if (pipe->ops->downcall == NULL)
 812		umode &= ~0222;
 813
 814	inode_lock_nested(dir, I_MUTEX_PARENT);
 815	dentry = __rpc_lookup_create_exclusive(parent, name);
 816	if (IS_ERR(dentry))
 817		goto out;
 818	err = __rpc_mkpipe_dentry(dir, dentry, umode, &rpc_pipe_fops,
 819				  private, pipe);
 820	if (err)
 821		goto out_err;
 822out:
 823	inode_unlock(dir);
 824	return dentry;
 825out_err:
 826	dentry = ERR_PTR(err);
 827	printk(KERN_WARNING "%s: %s() failed to create pipe %pd/%s (errno = %d)\n",
 828			__FILE__, __func__, parent, name,
 829			err);
 830	goto out;
 831}
 832EXPORT_SYMBOL_GPL(rpc_mkpipe_dentry);
 833
 834/**
 835 * rpc_unlink - remove a pipe
 836 * @dentry: dentry for the pipe, as returned from rpc_mkpipe
 837 *
 838 * After this call, lookups will no longer find the pipe, and any
 839 * attempts to read or write using preexisting opens of the pipe will
 840 * return -EPIPE.
 841 */
 842int
 843rpc_unlink(struct dentry *dentry)
 844{
 845	struct dentry *parent;
 846	struct inode *dir;
 847	int error = 0;
 848
 849	parent = dget_parent(dentry);
 850	dir = d_inode(parent);
 851	inode_lock_nested(dir, I_MUTEX_PARENT);
 852	error = __rpc_rmpipe(dir, dentry);
 853	inode_unlock(dir);
 854	dput(parent);
 855	return error;
 856}
 857EXPORT_SYMBOL_GPL(rpc_unlink);
 858
 859/**
 860 * rpc_init_pipe_dir_head - initialise a struct rpc_pipe_dir_head
 861 * @pdh: pointer to struct rpc_pipe_dir_head
 862 */
 863void rpc_init_pipe_dir_head(struct rpc_pipe_dir_head *pdh)
 864{
 865	INIT_LIST_HEAD(&pdh->pdh_entries);
 866	pdh->pdh_dentry = NULL;
 867}
 868EXPORT_SYMBOL_GPL(rpc_init_pipe_dir_head);
 869
 870/**
 871 * rpc_init_pipe_dir_object - initialise a struct rpc_pipe_dir_object
 872 * @pdo: pointer to struct rpc_pipe_dir_object
 873 * @pdo_ops: pointer to const struct rpc_pipe_dir_object_ops
 874 * @pdo_data: pointer to caller-defined data
 875 */
 876void rpc_init_pipe_dir_object(struct rpc_pipe_dir_object *pdo,
 877		const struct rpc_pipe_dir_object_ops *pdo_ops,
 878		void *pdo_data)
 879{
 880	INIT_LIST_HEAD(&pdo->pdo_head);
 881	pdo->pdo_ops = pdo_ops;
 882	pdo->pdo_data = pdo_data;
 883}
 884EXPORT_SYMBOL_GPL(rpc_init_pipe_dir_object);
 885
 886static int
 887rpc_add_pipe_dir_object_locked(struct net *net,
 888		struct rpc_pipe_dir_head *pdh,
 889		struct rpc_pipe_dir_object *pdo)
 890{
 891	int ret = 0;
 892
 893	if (pdh->pdh_dentry)
 894		ret = pdo->pdo_ops->create(pdh->pdh_dentry, pdo);
 895	if (ret == 0)
 896		list_add_tail(&pdo->pdo_head, &pdh->pdh_entries);
 897	return ret;
 898}
 899
 900static void
 901rpc_remove_pipe_dir_object_locked(struct net *net,
 902		struct rpc_pipe_dir_head *pdh,
 903		struct rpc_pipe_dir_object *pdo)
 904{
 905	if (pdh->pdh_dentry)
 906		pdo->pdo_ops->destroy(pdh->pdh_dentry, pdo);
 907	list_del_init(&pdo->pdo_head);
 908}
 909
 910/**
 911 * rpc_add_pipe_dir_object - associate a rpc_pipe_dir_object to a directory
 912 * @net: pointer to struct net
 913 * @pdh: pointer to struct rpc_pipe_dir_head
 914 * @pdo: pointer to struct rpc_pipe_dir_object
 915 *
 916 */
 917int
 918rpc_add_pipe_dir_object(struct net *net,
 919		struct rpc_pipe_dir_head *pdh,
 920		struct rpc_pipe_dir_object *pdo)
 921{
 922	int ret = 0;
 923
 924	if (list_empty(&pdo->pdo_head)) {
 925		struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 926
 927		mutex_lock(&sn->pipefs_sb_lock);
 928		ret = rpc_add_pipe_dir_object_locked(net, pdh, pdo);
 929		mutex_unlock(&sn->pipefs_sb_lock);
 930	}
 931	return ret;
 932}
 933EXPORT_SYMBOL_GPL(rpc_add_pipe_dir_object);
 934
 935/**
 936 * rpc_remove_pipe_dir_object - remove a rpc_pipe_dir_object from a directory
 937 * @net: pointer to struct net
 938 * @pdh: pointer to struct rpc_pipe_dir_head
 939 * @pdo: pointer to struct rpc_pipe_dir_object
 940 *
 941 */
 942void
 943rpc_remove_pipe_dir_object(struct net *net,
 944		struct rpc_pipe_dir_head *pdh,
 945		struct rpc_pipe_dir_object *pdo)
 946{
 947	if (!list_empty(&pdo->pdo_head)) {
 948		struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 949
 950		mutex_lock(&sn->pipefs_sb_lock);
 951		rpc_remove_pipe_dir_object_locked(net, pdh, pdo);
 952		mutex_unlock(&sn->pipefs_sb_lock);
 953	}
 954}
 955EXPORT_SYMBOL_GPL(rpc_remove_pipe_dir_object);
 956
 957/**
 958 * rpc_find_or_alloc_pipe_dir_object
 959 * @net: pointer to struct net
 960 * @pdh: pointer to struct rpc_pipe_dir_head
 961 * @match: match struct rpc_pipe_dir_object to data
 962 * @alloc: allocate a new struct rpc_pipe_dir_object
 963 * @data: user defined data for match() and alloc()
 964 *
 965 */
 966struct rpc_pipe_dir_object *
 967rpc_find_or_alloc_pipe_dir_object(struct net *net,
 968		struct rpc_pipe_dir_head *pdh,
 969		int (*match)(struct rpc_pipe_dir_object *, void *),
 970		struct rpc_pipe_dir_object *(*alloc)(void *),
 971		void *data)
 972{
 973	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 974	struct rpc_pipe_dir_object *pdo;
 975
 976	mutex_lock(&sn->pipefs_sb_lock);
 977	list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head) {
 978		if (!match(pdo, data))
 979			continue;
 980		goto out;
 981	}
 982	pdo = alloc(data);
 983	if (!pdo)
 984		goto out;
 985	rpc_add_pipe_dir_object_locked(net, pdh, pdo);
 986out:
 987	mutex_unlock(&sn->pipefs_sb_lock);
 988	return pdo;
 989}
 990EXPORT_SYMBOL_GPL(rpc_find_or_alloc_pipe_dir_object);
 991
 992static void
 993rpc_create_pipe_dir_objects(struct rpc_pipe_dir_head *pdh)
 994{
 995	struct rpc_pipe_dir_object *pdo;
 996	struct dentry *dir = pdh->pdh_dentry;
 997
 998	list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head)
 999		pdo->pdo_ops->create(dir, pdo);
1000}
1001
1002static void
1003rpc_destroy_pipe_dir_objects(struct rpc_pipe_dir_head *pdh)
1004{
1005	struct rpc_pipe_dir_object *pdo;
1006	struct dentry *dir = pdh->pdh_dentry;
1007
1008	list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head)
1009		pdo->pdo_ops->destroy(dir, pdo);
1010}
1011
1012enum {
1013	RPCAUTH_info,
1014	RPCAUTH_EOF
1015};
1016
1017static const struct rpc_filelist authfiles[] = {
1018	[RPCAUTH_info] = {
1019		.name = "info",
1020		.i_fop = &rpc_info_operations,
1021		.mode = S_IFREG | 0400,
1022	},
1023};
1024
1025static int rpc_clntdir_populate(struct dentry *dentry, void *private)
1026{
1027	return rpc_populate(dentry,
1028			    authfiles, RPCAUTH_info, RPCAUTH_EOF,
1029			    private);
1030}
1031
1032static void rpc_clntdir_depopulate(struct dentry *dentry)
1033{
1034	rpc_depopulate(dentry, authfiles, RPCAUTH_info, RPCAUTH_EOF);
1035}
1036
1037/**
1038 * rpc_create_client_dir - Create a new rpc_client directory in rpc_pipefs
1039 * @dentry: the parent of new directory
1040 * @name: the name of new directory
1041 * @rpc_client: rpc client to associate with this directory
1042 *
1043 * This creates a directory at the given @path associated with
1044 * @rpc_clnt, which will contain a file named "info" with some basic
1045 * information about the client, together with any "pipes" that may
1046 * later be created using rpc_mkpipe().
1047 */
1048struct dentry *rpc_create_client_dir(struct dentry *dentry,
1049				   const char *name,
1050				   struct rpc_clnt *rpc_client)
1051{
1052	struct dentry *ret;
1053
1054	ret = rpc_mkdir_populate(dentry, name, 0555, NULL,
1055				 rpc_clntdir_populate, rpc_client);
1056	if (!IS_ERR(ret)) {
1057		rpc_client->cl_pipedir_objects.pdh_dentry = ret;
1058		rpc_create_pipe_dir_objects(&rpc_client->cl_pipedir_objects);
1059	}
1060	return ret;
1061}
1062
1063/**
1064 * rpc_remove_client_dir - Remove a directory created with rpc_create_client_dir()
1065 * @rpc_client: rpc_client for the pipe
1066 */
1067int rpc_remove_client_dir(struct rpc_clnt *rpc_client)
1068{
1069	struct dentry *dentry = rpc_client->cl_pipedir_objects.pdh_dentry;
1070
1071	if (dentry == NULL)
1072		return 0;
1073	rpc_destroy_pipe_dir_objects(&rpc_client->cl_pipedir_objects);
1074	rpc_client->cl_pipedir_objects.pdh_dentry = NULL;
1075	return rpc_rmdir_depopulate(dentry, rpc_clntdir_depopulate);
1076}
1077
1078static const struct rpc_filelist cache_pipefs_files[3] = {
1079	[0] = {
1080		.name = "channel",
1081		.i_fop = &cache_file_operations_pipefs,
1082		.mode = S_IFREG | 0600,
1083	},
1084	[1] = {
1085		.name = "content",
1086		.i_fop = &content_file_operations_pipefs,
1087		.mode = S_IFREG | 0400,
1088	},
1089	[2] = {
1090		.name = "flush",
1091		.i_fop = &cache_flush_operations_pipefs,
1092		.mode = S_IFREG | 0600,
1093	},
1094};
1095
1096static int rpc_cachedir_populate(struct dentry *dentry, void *private)
1097{
1098	return rpc_populate(dentry,
1099			    cache_pipefs_files, 0, 3,
1100			    private);
1101}
1102
1103static void rpc_cachedir_depopulate(struct dentry *dentry)
1104{
1105	rpc_depopulate(dentry, cache_pipefs_files, 0, 3);
1106}
1107
1108struct dentry *rpc_create_cache_dir(struct dentry *parent, const char *name,
1109				    umode_t umode, struct cache_detail *cd)
1110{
1111	return rpc_mkdir_populate(parent, name, umode, NULL,
1112			rpc_cachedir_populate, cd);
1113}
1114
1115void rpc_remove_cache_dir(struct dentry *dentry)
1116{
1117	rpc_rmdir_depopulate(dentry, rpc_cachedir_depopulate);
1118}
1119
1120/*
1121 * populate the filesystem
1122 */
1123static const struct super_operations s_ops = {
1124	.alloc_inode	= rpc_alloc_inode,
1125	.free_inode	= rpc_free_inode,
1126	.statfs		= simple_statfs,
1127};
1128
1129#define RPCAUTH_GSSMAGIC 0x67596969
1130
1131/*
1132 * We have a single directory with 1 node in it.
1133 */
1134enum {
1135	RPCAUTH_lockd,
1136	RPCAUTH_mount,
1137	RPCAUTH_nfs,
1138	RPCAUTH_portmap,
1139	RPCAUTH_statd,
1140	RPCAUTH_nfsd4_cb,
1141	RPCAUTH_cache,
1142	RPCAUTH_nfsd,
1143	RPCAUTH_gssd,
1144	RPCAUTH_RootEOF
1145};
1146
1147static const struct rpc_filelist files[] = {
1148	[RPCAUTH_lockd] = {
1149		.name = "lockd",
1150		.mode = S_IFDIR | 0555,
1151	},
1152	[RPCAUTH_mount] = {
1153		.name = "mount",
1154		.mode = S_IFDIR | 0555,
1155	},
1156	[RPCAUTH_nfs] = {
1157		.name = "nfs",
1158		.mode = S_IFDIR | 0555,
1159	},
1160	[RPCAUTH_portmap] = {
1161		.name = "portmap",
1162		.mode = S_IFDIR | 0555,
1163	},
1164	[RPCAUTH_statd] = {
1165		.name = "statd",
1166		.mode = S_IFDIR | 0555,
1167	},
1168	[RPCAUTH_nfsd4_cb] = {
1169		.name = "nfsd4_cb",
1170		.mode = S_IFDIR | 0555,
1171	},
1172	[RPCAUTH_cache] = {
1173		.name = "cache",
1174		.mode = S_IFDIR | 0555,
1175	},
1176	[RPCAUTH_nfsd] = {
1177		.name = "nfsd",
1178		.mode = S_IFDIR | 0555,
1179	},
1180	[RPCAUTH_gssd] = {
1181		.name = "gssd",
1182		.mode = S_IFDIR | 0555,
1183	},
1184};
1185
1186/*
1187 * This call can be used only in RPC pipefs mount notification hooks.
1188 */
1189struct dentry *rpc_d_lookup_sb(const struct super_block *sb,
1190			       const unsigned char *dir_name)
1191{
1192	struct qstr dir = QSTR_INIT(dir_name, strlen(dir_name));
1193	return d_hash_and_lookup(sb->s_root, &dir);
1194}
1195EXPORT_SYMBOL_GPL(rpc_d_lookup_sb);
1196
1197int rpc_pipefs_init_net(struct net *net)
1198{
1199	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1200
1201	sn->gssd_dummy = rpc_mkpipe_data(&gssd_dummy_pipe_ops, 0);
1202	if (IS_ERR(sn->gssd_dummy))
1203		return PTR_ERR(sn->gssd_dummy);
1204
1205	mutex_init(&sn->pipefs_sb_lock);
1206	sn->pipe_version = -1;
1207	return 0;
1208}
1209
1210void rpc_pipefs_exit_net(struct net *net)
1211{
1212	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1213
1214	rpc_destroy_pipe_data(sn->gssd_dummy);
1215}
1216
1217/*
1218 * This call will be used for per network namespace operations calls.
1219 * Note: Function will be returned with pipefs_sb_lock taken if superblock was
1220 * found. This lock have to be released by rpc_put_sb_net() when all operations
1221 * will be completed.
1222 */
1223struct super_block *rpc_get_sb_net(const struct net *net)
1224{
1225	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1226
1227	mutex_lock(&sn->pipefs_sb_lock);
1228	if (sn->pipefs_sb)
1229		return sn->pipefs_sb;
1230	mutex_unlock(&sn->pipefs_sb_lock);
1231	return NULL;
1232}
1233EXPORT_SYMBOL_GPL(rpc_get_sb_net);
1234
1235void rpc_put_sb_net(const struct net *net)
1236{
1237	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1238
1239	WARN_ON(sn->pipefs_sb == NULL);
1240	mutex_unlock(&sn->pipefs_sb_lock);
1241}
1242EXPORT_SYMBOL_GPL(rpc_put_sb_net);
1243
1244static const struct rpc_filelist gssd_dummy_clnt_dir[] = {
1245	[0] = {
1246		.name = "clntXX",
1247		.mode = S_IFDIR | 0555,
1248	},
1249};
1250
1251static ssize_t
1252dummy_downcall(struct file *filp, const char __user *src, size_t len)
1253{
1254	return -EINVAL;
1255}
1256
1257static const struct rpc_pipe_ops gssd_dummy_pipe_ops = {
1258	.upcall		= rpc_pipe_generic_upcall,
1259	.downcall	= dummy_downcall,
1260};
1261
1262/*
1263 * Here we present a bogus "info" file to keep rpc.gssd happy. We don't expect
1264 * that it will ever use this info to handle an upcall, but rpc.gssd expects
1265 * that this file will be there and have a certain format.
1266 */
1267static int
1268rpc_dummy_info_show(struct seq_file *m, void *v)
1269{
1270	seq_printf(m, "RPC server: %s\n", utsname()->nodename);
1271	seq_printf(m, "service: foo (1) version 0\n");
1272	seq_printf(m, "address: 127.0.0.1\n");
1273	seq_printf(m, "protocol: tcp\n");
1274	seq_printf(m, "port: 0\n");
1275	return 0;
1276}
1277DEFINE_SHOW_ATTRIBUTE(rpc_dummy_info);
1278
1279static const struct rpc_filelist gssd_dummy_info_file[] = {
1280	[0] = {
1281		.name = "info",
1282		.i_fop = &rpc_dummy_info_fops,
1283		.mode = S_IFREG | 0400,
1284	},
1285};
1286
1287/**
1288 * rpc_gssd_dummy_populate - create a dummy gssd pipe
1289 * @root:	root of the rpc_pipefs filesystem
1290 * @pipe_data:	pipe data created when netns is initialized
1291 *
1292 * Create a dummy set of directories and a pipe that gssd can hold open to
1293 * indicate that it is up and running.
1294 */
1295static struct dentry *
1296rpc_gssd_dummy_populate(struct dentry *root, struct rpc_pipe *pipe_data)
1297{
1298	int ret = 0;
1299	struct dentry *gssd_dentry;
1300	struct dentry *clnt_dentry = NULL;
1301	struct dentry *pipe_dentry = NULL;
1302	struct qstr q = QSTR_INIT(files[RPCAUTH_gssd].name,
1303				  strlen(files[RPCAUTH_gssd].name));
1304
1305	/* We should never get this far if "gssd" doesn't exist */
1306	gssd_dentry = d_hash_and_lookup(root, &q);
1307	if (!gssd_dentry)
1308		return ERR_PTR(-ENOENT);
1309
1310	ret = rpc_populate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1, NULL);
1311	if (ret) {
1312		pipe_dentry = ERR_PTR(ret);
1313		goto out;
1314	}
1315
1316	q.name = gssd_dummy_clnt_dir[0].name;
1317	q.len = strlen(gssd_dummy_clnt_dir[0].name);
1318	clnt_dentry = d_hash_and_lookup(gssd_dentry, &q);
1319	if (!clnt_dentry) {
 
1320		pipe_dentry = ERR_PTR(-ENOENT);
1321		goto out;
1322	}
1323
1324	ret = rpc_populate(clnt_dentry, gssd_dummy_info_file, 0, 1, NULL);
1325	if (ret) {
1326		__rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1);
1327		pipe_dentry = ERR_PTR(ret);
1328		goto out;
1329	}
1330
1331	pipe_dentry = rpc_mkpipe_dentry(clnt_dentry, "gssd", NULL, pipe_data);
1332	if (IS_ERR(pipe_dentry)) {
1333		__rpc_depopulate(clnt_dentry, gssd_dummy_info_file, 0, 1);
1334		__rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1);
1335	}
1336out:
1337	dput(clnt_dentry);
1338	dput(gssd_dentry);
1339	return pipe_dentry;
1340}
1341
1342static void
1343rpc_gssd_dummy_depopulate(struct dentry *pipe_dentry)
1344{
1345	struct dentry *clnt_dir = pipe_dentry->d_parent;
1346	struct dentry *gssd_dir = clnt_dir->d_parent;
1347
1348	dget(pipe_dentry);
1349	__rpc_rmpipe(d_inode(clnt_dir), pipe_dentry);
1350	__rpc_depopulate(clnt_dir, gssd_dummy_info_file, 0, 1);
1351	__rpc_depopulate(gssd_dir, gssd_dummy_clnt_dir, 0, 1);
1352	dput(pipe_dentry);
1353}
1354
1355static int
1356rpc_fill_super(struct super_block *sb, struct fs_context *fc)
1357{
1358	struct inode *inode;
1359	struct dentry *root, *gssd_dentry;
1360	struct net *net = sb->s_fs_info;
1361	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1362	int err;
1363
1364	sb->s_blocksize = PAGE_SIZE;
1365	sb->s_blocksize_bits = PAGE_SHIFT;
1366	sb->s_magic = RPCAUTH_GSSMAGIC;
1367	sb->s_op = &s_ops;
1368	sb->s_d_op = &simple_dentry_operations;
1369	sb->s_time_gran = 1;
1370
1371	inode = rpc_get_inode(sb, S_IFDIR | 0555);
1372	sb->s_root = root = d_make_root(inode);
1373	if (!root)
1374		return -ENOMEM;
1375	if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL))
1376		return -ENOMEM;
1377
1378	gssd_dentry = rpc_gssd_dummy_populate(root, sn->gssd_dummy);
1379	if (IS_ERR(gssd_dentry)) {
1380		__rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
1381		return PTR_ERR(gssd_dentry);
1382	}
1383
1384	dprintk("RPC:       sending pipefs MOUNT notification for net %x%s\n",
1385		net->ns.inum, NET_NAME(net));
1386	mutex_lock(&sn->pipefs_sb_lock);
1387	sn->pipefs_sb = sb;
1388	err = blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1389					   RPC_PIPEFS_MOUNT,
1390					   sb);
1391	if (err)
1392		goto err_depopulate;
1393	mutex_unlock(&sn->pipefs_sb_lock);
1394	return 0;
1395
1396err_depopulate:
1397	rpc_gssd_dummy_depopulate(gssd_dentry);
1398	blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1399					   RPC_PIPEFS_UMOUNT,
1400					   sb);
1401	sn->pipefs_sb = NULL;
1402	__rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
1403	mutex_unlock(&sn->pipefs_sb_lock);
1404	return err;
1405}
1406
1407bool
1408gssd_running(struct net *net)
1409{
1410	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1411	struct rpc_pipe *pipe = sn->gssd_dummy;
1412
1413	return pipe->nreaders || pipe->nwriters;
1414}
1415EXPORT_SYMBOL_GPL(gssd_running);
1416
1417static int rpc_fs_get_tree(struct fs_context *fc)
1418{
1419	return get_tree_keyed(fc, rpc_fill_super, get_net(fc->net_ns));
1420}
1421
1422static void rpc_fs_free_fc(struct fs_context *fc)
1423{
1424	if (fc->s_fs_info)
1425		put_net(fc->s_fs_info);
1426}
1427
1428static const struct fs_context_operations rpc_fs_context_ops = {
1429	.free		= rpc_fs_free_fc,
1430	.get_tree	= rpc_fs_get_tree,
1431};
1432
1433static int rpc_init_fs_context(struct fs_context *fc)
1434{
1435	put_user_ns(fc->user_ns);
1436	fc->user_ns = get_user_ns(fc->net_ns->user_ns);
1437	fc->ops = &rpc_fs_context_ops;
1438	return 0;
1439}
1440
1441static void rpc_kill_sb(struct super_block *sb)
1442{
1443	struct net *net = sb->s_fs_info;
1444	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1445
1446	mutex_lock(&sn->pipefs_sb_lock);
1447	if (sn->pipefs_sb != sb) {
1448		mutex_unlock(&sn->pipefs_sb_lock);
1449		goto out;
1450	}
1451	sn->pipefs_sb = NULL;
1452	dprintk("RPC:       sending pipefs UMOUNT notification for net %x%s\n",
1453		net->ns.inum, NET_NAME(net));
1454	blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1455					   RPC_PIPEFS_UMOUNT,
1456					   sb);
1457	mutex_unlock(&sn->pipefs_sb_lock);
1458out:
1459	kill_litter_super(sb);
1460	put_net(net);
1461}
1462
1463static struct file_system_type rpc_pipe_fs_type = {
1464	.owner		= THIS_MODULE,
1465	.name		= "rpc_pipefs",
1466	.init_fs_context = rpc_init_fs_context,
1467	.kill_sb	= rpc_kill_sb,
1468};
1469MODULE_ALIAS_FS("rpc_pipefs");
1470MODULE_ALIAS("rpc_pipefs");
1471
1472static void
1473init_once(void *foo)
1474{
1475	struct rpc_inode *rpci = (struct rpc_inode *) foo;
1476
1477	inode_init_once(&rpci->vfs_inode);
1478	rpci->private = NULL;
1479	rpci->pipe = NULL;
1480	init_waitqueue_head(&rpci->waitq);
1481}
1482
1483int register_rpc_pipefs(void)
1484{
1485	int err;
1486
1487	rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
1488				sizeof(struct rpc_inode),
1489				0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
1490						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1491				init_once);
1492	if (!rpc_inode_cachep)
1493		return -ENOMEM;
1494	err = rpc_clients_notifier_register();
1495	if (err)
1496		goto err_notifier;
1497	err = register_filesystem(&rpc_pipe_fs_type);
1498	if (err)
1499		goto err_register;
1500	return 0;
1501
1502err_register:
1503	rpc_clients_notifier_unregister();
1504err_notifier:
1505	kmem_cache_destroy(rpc_inode_cachep);
1506	return err;
1507}
1508
1509void unregister_rpc_pipefs(void)
1510{
1511	rpc_clients_notifier_unregister();
1512	kmem_cache_destroy(rpc_inode_cachep);
1513	unregister_filesystem(&rpc_pipe_fs_type);
 
1514}