rpc_pipe.c 22.0 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5
/*
 * net/sunrpc/rpc_pipe.c
 *
 * Userland/kernel interface for rpcauth_gss.
 * Code shamelessly plagiarized from fs/nfsd/nfsctl.c
6
 * and fs/sysfs/inode.c
L
Linus Torvalds 已提交
7 8 9 10 11 12 13 14 15 16
 *
 * Copyright (c) 2002, Trond Myklebust <trond.myklebust@fys.uio.no>
 *
 */
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/pagemap.h>
#include <linux/mount.h>
#include <linux/namei.h>
17
#include <linux/fsnotify.h>
L
Linus Torvalds 已提交
18 19 20 21 22 23 24 25 26 27 28 29
#include <linux/kernel.h>

#include <asm/ioctls.h>
#include <linux/fs.h>
#include <linux/poll.h>
#include <linux/wait.h>
#include <linux/seq_file.h>

#include <linux/sunrpc/clnt.h>
#include <linux/workqueue.h>
#include <linux/sunrpc/rpc_pipe_fs.h>

30
static struct vfsmount *rpc_mount __read_mostly;
L
Linus Torvalds 已提交
31 32 33 34 35
static int rpc_mount_count;

static struct file_system_type rpc_pipe_fs_type;


36
static struct kmem_cache *rpc_inode_cachep __read_mostly;
L
Linus Torvalds 已提交
37 38 39

#define RPC_UPCALL_TIMEOUT (30*HZ)

40 41
static void rpc_purge_list(struct rpc_inode *rpci, struct list_head *head,
		void (*destroy_msg)(struct rpc_pipe_msg *), int err)
L
Linus Torvalds 已提交
42 43 44
{
	struct rpc_pipe_msg *msg;

45 46 47
	if (list_empty(head))
		return;
	do {
48
		msg = list_entry(head->next, struct rpc_pipe_msg, list);
49
		list_del(&msg->list);
L
Linus Torvalds 已提交
50
		msg->errno = err;
51
		destroy_msg(msg);
52
	} while (!list_empty(head));
L
Linus Torvalds 已提交
53 54 55 56
	wake_up(&rpci->waitq);
}

static void
57
rpc_timeout_upcall_queue(struct work_struct *work)
L
Linus Torvalds 已提交
58
{
59
	LIST_HEAD(free_list);
60 61
	struct rpc_inode *rpci =
		container_of(work, struct rpc_inode, queue_timeout.work);
L
Linus Torvalds 已提交
62
	struct inode *inode = &rpci->vfs_inode;
63
	void (*destroy_msg)(struct rpc_pipe_msg *);
L
Linus Torvalds 已提交
64

65 66 67 68 69 70 71 72 73 74 75 76
	spin_lock(&inode->i_lock);
	if (rpci->ops == NULL) {
		spin_unlock(&inode->i_lock);
		return;
	}
	destroy_msg = rpci->ops->destroy_msg;
	if (rpci->nreaders == 0) {
		list_splice_init(&rpci->pipe, &free_list);
		rpci->pipelen = 0;
	}
	spin_unlock(&inode->i_lock);
	rpc_purge_list(rpci, &free_list, destroy_msg, -ETIMEDOUT);
L
Linus Torvalds 已提交
77 78
}

79 80 81 82 83 84 85 86 87 88
/**
 * rpc_queue_upcall
 * @inode: inode of upcall pipe on which to queue given message
 * @msg: message to queue
 *
 * Call with an @inode created by rpc_mkpipe() to queue an upcall.
 * A userspace process may then later read the upcall by performing a
 * read on an open file for this inode.  It is up to the caller to
 * initialize the fields of @msg (other than @msg->list) appropriately.
 */
L
Linus Torvalds 已提交
89 90 91 92
int
rpc_queue_upcall(struct inode *inode, struct rpc_pipe_msg *msg)
{
	struct rpc_inode *rpci = RPC_I(inode);
93
	int res = -EPIPE;
L
Linus Torvalds 已提交
94

95
	spin_lock(&inode->i_lock);
96 97
	if (rpci->ops == NULL)
		goto out;
L
Linus Torvalds 已提交
98 99 100
	if (rpci->nreaders) {
		list_add_tail(&msg->list, &rpci->pipe);
		rpci->pipelen += msg->len;
101
		res = 0;
L
Linus Torvalds 已提交
102 103
	} else if (rpci->flags & RPC_PIPE_WAIT_FOR_OPEN) {
		if (list_empty(&rpci->pipe))
104 105
			queue_delayed_work(rpciod_workqueue,
					&rpci->queue_timeout,
L
Linus Torvalds 已提交
106 107 108
					RPC_UPCALL_TIMEOUT);
		list_add_tail(&msg->list, &rpci->pipe);
		rpci->pipelen += msg->len;
109 110 111
		res = 0;
	}
out:
112
	spin_unlock(&inode->i_lock);
L
Linus Torvalds 已提交
113 114 115
	wake_up(&rpci->waitq);
	return res;
}
116
EXPORT_SYMBOL_GPL(rpc_queue_upcall);
L
Linus Torvalds 已提交
117

118 119 120 121 122 123
static inline void
rpc_inode_setowner(struct inode *inode, void *private)
{
	RPC_I(inode)->private = private;
}

L
Linus Torvalds 已提交
124 125 126 127
static void
rpc_close_pipes(struct inode *inode)
{
	struct rpc_inode *rpci = RPC_I(inode);
128
	const struct rpc_pipe_ops *ops;
129
	int need_release;
L
Linus Torvalds 已提交
130

131
	mutex_lock(&inode->i_mutex);
132 133 134 135
	ops = rpci->ops;
	if (ops != NULL) {
		LIST_HEAD(free_list);
		spin_lock(&inode->i_lock);
136
		need_release = rpci->nreaders != 0 || rpci->nwriters != 0;
L
Linus Torvalds 已提交
137
		rpci->nreaders = 0;
138 139 140
		list_splice_init(&rpci->in_upcall, &free_list);
		list_splice_init(&rpci->pipe, &free_list);
		rpci->pipelen = 0;
L
Linus Torvalds 已提交
141
		rpci->ops = NULL;
142 143 144
		spin_unlock(&inode->i_lock);
		rpc_purge_list(rpci, &free_list, ops->destroy_msg, -EPIPE);
		rpci->nwriters = 0;
145
		if (need_release && ops->release_pipe)
146
			ops->release_pipe(inode);
147
		cancel_delayed_work_sync(&rpci->queue_timeout);
L
Linus Torvalds 已提交
148
	}
149
	rpc_inode_setowner(inode, NULL);
150
	mutex_unlock(&inode->i_mutex);
L
Linus Torvalds 已提交
151 152 153 154 155 156
}

static struct inode *
rpc_alloc_inode(struct super_block *sb)
{
	struct rpc_inode *rpci;
157
	rpci = (struct rpc_inode *)kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL);
L
Linus Torvalds 已提交
158 159 160 161 162 163 164 165 166 167 168 169 170 171 172
	if (!rpci)
		return NULL;
	return &rpci->vfs_inode;
}

static void
rpc_destroy_inode(struct inode *inode)
{
	kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
}

static int
rpc_pipe_open(struct inode *inode, struct file *filp)
{
	struct rpc_inode *rpci = RPC_I(inode);
173
	int first_open;
L
Linus Torvalds 已提交
174 175
	int res = -ENXIO;

176
	mutex_lock(&inode->i_mutex);
177 178 179 180 181 182 183
	if (rpci->ops == NULL)
		goto out;
	first_open = rpci->nreaders == 0 && rpci->nwriters == 0;
	if (first_open && rpci->ops->open_pipe) {
		res = rpci->ops->open_pipe(inode);
		if (res)
			goto out;
L
Linus Torvalds 已提交
184
	}
185 186 187 188 189 190
	if (filp->f_mode & FMODE_READ)
		rpci->nreaders++;
	if (filp->f_mode & FMODE_WRITE)
		rpci->nwriters++;
	res = 0;
out:
191
	mutex_unlock(&inode->i_mutex);
L
Linus Torvalds 已提交
192 193 194 195 196 197
	return res;
}

static int
rpc_pipe_release(struct inode *inode, struct file *filp)
{
198
	struct rpc_inode *rpci = RPC_I(inode);
L
Linus Torvalds 已提交
199
	struct rpc_pipe_msg *msg;
200
	int last_close;
L
Linus Torvalds 已提交
201

202
	mutex_lock(&inode->i_mutex);
L
Linus Torvalds 已提交
203 204 205 206
	if (rpci->ops == NULL)
		goto out;
	msg = (struct rpc_pipe_msg *)filp->private_data;
	if (msg != NULL) {
207
		spin_lock(&inode->i_lock);
208
		msg->errno = -EAGAIN;
209 210
		list_del(&msg->list);
		spin_unlock(&inode->i_lock);
L
Linus Torvalds 已提交
211 212 213 214
		rpci->ops->destroy_msg(msg);
	}
	if (filp->f_mode & FMODE_WRITE)
		rpci->nwriters --;
215
	if (filp->f_mode & FMODE_READ) {
L
Linus Torvalds 已提交
216
		rpci->nreaders --;
217 218 219 220 221 222 223 224 225 226
		if (rpci->nreaders == 0) {
			LIST_HEAD(free_list);
			spin_lock(&inode->i_lock);
			list_splice_init(&rpci->pipe, &free_list);
			rpci->pipelen = 0;
			spin_unlock(&inode->i_lock);
			rpc_purge_list(rpci, &free_list,
					rpci->ops->destroy_msg, -EAGAIN);
		}
	}
227 228
	last_close = rpci->nwriters == 0 && rpci->nreaders == 0;
	if (last_close && rpci->ops->release_pipe)
L
Linus Torvalds 已提交
229 230
		rpci->ops->release_pipe(inode);
out:
231
	mutex_unlock(&inode->i_mutex);
L
Linus Torvalds 已提交
232 233 234 235 236 237
	return 0;
}

static ssize_t
rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
{
J
Josef Sipek 已提交
238
	struct inode *inode = filp->f_path.dentry->d_inode;
L
Linus Torvalds 已提交
239 240 241 242
	struct rpc_inode *rpci = RPC_I(inode);
	struct rpc_pipe_msg *msg;
	int res = 0;

243
	mutex_lock(&inode->i_mutex);
L
Linus Torvalds 已提交
244 245 246 247 248 249
	if (rpci->ops == NULL) {
		res = -EPIPE;
		goto out_unlock;
	}
	msg = filp->private_data;
	if (msg == NULL) {
250
		spin_lock(&inode->i_lock);
L
Linus Torvalds 已提交
251 252 253 254 255 256 257 258 259
		if (!list_empty(&rpci->pipe)) {
			msg = list_entry(rpci->pipe.next,
					struct rpc_pipe_msg,
					list);
			list_move(&msg->list, &rpci->in_upcall);
			rpci->pipelen -= msg->len;
			filp->private_data = msg;
			msg->copied = 0;
		}
260
		spin_unlock(&inode->i_lock);
L
Linus Torvalds 已提交
261 262 263 264 265 266 267
		if (msg == NULL)
			goto out_unlock;
	}
	/* NOTE: it is up to the callback to update msg->copied */
	res = rpci->ops->upcall(filp, msg, buf, len);
	if (res < 0 || msg->len == msg->copied) {
		filp->private_data = NULL;
268 269 270
		spin_lock(&inode->i_lock);
		list_del(&msg->list);
		spin_unlock(&inode->i_lock);
L
Linus Torvalds 已提交
271 272 273
		rpci->ops->destroy_msg(msg);
	}
out_unlock:
274
	mutex_unlock(&inode->i_mutex);
L
Linus Torvalds 已提交
275 276 277 278 279 280
	return res;
}

static ssize_t
rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
{
J
Josef Sipek 已提交
281
	struct inode *inode = filp->f_path.dentry->d_inode;
L
Linus Torvalds 已提交
282 283 284
	struct rpc_inode *rpci = RPC_I(inode);
	int res;

285
	mutex_lock(&inode->i_mutex);
L
Linus Torvalds 已提交
286 287 288
	res = -EPIPE;
	if (rpci->ops != NULL)
		res = rpci->ops->downcall(filp, buf, len);
289
	mutex_unlock(&inode->i_mutex);
L
Linus Torvalds 已提交
290 291 292 293 294 295 296 297 298
	return res;
}

static unsigned int
rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
{
	struct rpc_inode *rpci;
	unsigned int mask = 0;

J
Josef Sipek 已提交
299
	rpci = RPC_I(filp->f_path.dentry->d_inode);
L
Linus Torvalds 已提交
300 301 302 303 304
	poll_wait(filp, &rpci->waitq, wait);

	mask = POLLOUT | POLLWRNORM;
	if (rpci->ops == NULL)
		mask |= POLLERR | POLLHUP;
305
	if (filp->private_data || !list_empty(&rpci->pipe))
L
Linus Torvalds 已提交
306 307 308 309 310 311 312 313
		mask |= POLLIN | POLLRDNORM;
	return mask;
}

static int
rpc_pipe_ioctl(struct inode *ino, struct file *filp,
		unsigned int cmd, unsigned long arg)
{
J
Josef Sipek 已提交
314
	struct rpc_inode *rpci = RPC_I(filp->f_path.dentry->d_inode);
L
Linus Torvalds 已提交
315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332
	int len;

	switch (cmd) {
	case FIONREAD:
		if (rpci->ops == NULL)
			return -EPIPE;
		len = rpci->pipelen;
		if (filp->private_data) {
			struct rpc_pipe_msg *msg;
			msg = (struct rpc_pipe_msg *)filp->private_data;
			len += msg->len - msg->copied;
		}
		return put_user(len, (int __user *)arg);
	default:
		return -EINVAL;
	}
}

333
static const struct file_operations rpc_pipe_fops = {
L
Linus Torvalds 已提交
334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.read		= rpc_pipe_read,
	.write		= rpc_pipe_write,
	.poll		= rpc_pipe_poll,
	.ioctl		= rpc_pipe_ioctl,
	.open		= rpc_pipe_open,
	.release	= rpc_pipe_release,
};

static int
rpc_show_info(struct seq_file *m, void *v)
{
	struct rpc_clnt *clnt = m->private;

	seq_printf(m, "RPC server: %s\n", clnt->cl_server);
	seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_protname,
			clnt->cl_prog, clnt->cl_vers);
352 353
	seq_printf(m, "address: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
	seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO));
354
	seq_printf(m, "port: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PORT));
L
Linus Torvalds 已提交
355 356 357 358 359 360 361 362 363 364 365
	return 0;
}

static int
rpc_info_open(struct inode *inode, struct file *file)
{
	struct rpc_clnt *clnt;
	int ret = single_open(file, rpc_show_info, NULL);

	if (!ret) {
		struct seq_file *m = file->private_data;
366
		mutex_lock(&inode->i_mutex);
L
Linus Torvalds 已提交
367 368
		clnt = RPC_I(inode)->private;
		if (clnt) {
369
			kref_get(&clnt->cl_kref);
L
Linus Torvalds 已提交
370 371 372 373 374
			m->private = clnt;
		} else {
			single_release(inode, file);
			ret = -EINVAL;
		}
375
		mutex_unlock(&inode->i_mutex);
L
Linus Torvalds 已提交
376 377 378 379 380 381 382 383 384 385 386 387 388 389 390
	}
	return ret;
}

static int
rpc_info_release(struct inode *inode, struct file *file)
{
	struct seq_file *m = file->private_data;
	struct rpc_clnt *clnt = (struct rpc_clnt *)m->private;

	if (clnt)
		rpc_release_client(clnt);
	return single_release(inode, file);
}

391
static const struct file_operations rpc_info_operations = {
L
Linus Torvalds 已提交
392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409
	.owner		= THIS_MODULE,
	.open		= rpc_info_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= rpc_info_release,
};


/*
 * We have a single directory with 1 node in it.
 */
enum {
	RPCAUTH_Root = 1,
	RPCAUTH_lockd,
	RPCAUTH_mount,
	RPCAUTH_nfs,
	RPCAUTH_portmap,
	RPCAUTH_statd,
410
	RPCAUTH_nfsd4_cb,
L
Linus Torvalds 已提交
411 412 413 414 415 416 417 418
	RPCAUTH_RootEOF
};

/*
 * Description of fs contents.
 */
struct rpc_filelist {
	char *name;
419
	const struct file_operations *i_fop;
L
Linus Torvalds 已提交
420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443
	int mode;
};

static struct rpc_filelist files[] = {
	[RPCAUTH_lockd] = {
		.name = "lockd",
		.mode = S_IFDIR | S_IRUGO | S_IXUGO,
	},
	[RPCAUTH_mount] = {
		.name = "mount",
		.mode = S_IFDIR | S_IRUGO | S_IXUGO,
	},
	[RPCAUTH_nfs] = {
		.name = "nfs",
		.mode = S_IFDIR | S_IRUGO | S_IXUGO,
	},
	[RPCAUTH_portmap] = {
		.name = "portmap",
		.mode = S_IFDIR | S_IRUGO | S_IXUGO,
	},
	[RPCAUTH_statd] = {
		.name = "statd",
		.mode = S_IFDIR | S_IRUGO | S_IXUGO,
	},
444 445 446 447
	[RPCAUTH_nfsd4_cb] = {
		.name = "nfsd4_cb",
		.mode = S_IFDIR | S_IRUGO | S_IXUGO,
	},
L
Linus Torvalds 已提交
448 449 450 451 452 453 454 455 456 457 458 459 460 461 462
};

enum {
	RPCAUTH_info = 2,
	RPCAUTH_EOF
};

static struct rpc_filelist authfiles[] = {
	[RPCAUTH_info] = {
		.name = "info",
		.i_fop = &rpc_info_operations,
		.mode = S_IFREG | S_IRUSR,
	},
};

463
struct vfsmount *rpc_get_mount(void)
L
Linus Torvalds 已提交
464
{
465 466
	int err;

467
	err = simple_pin_fs(&rpc_pipe_fs_type, &rpc_mount, &rpc_mount_count);
468 469 470
	if (err != 0)
		return ERR_PTR(err);
	return rpc_mount;
L
Linus Torvalds 已提交
471 472
}

473
void rpc_put_mount(void)
L
Linus Torvalds 已提交
474 475 476 477
{
	simple_release_fs(&rpc_mount, &rpc_mount_count);
}

T
Trond Myklebust 已提交
478 479 480 481 482
static int rpc_delete_dentry(struct dentry *dentry)
{
	return 1;
}

A
Al Viro 已提交
483
static const struct dentry_operations rpc_dentry_operations = {
T
Trond Myklebust 已提交
484 485 486
	.d_delete = rpc_delete_dentry,
};

487 488 489
static int
rpc_lookup_parent(char *path, struct nameidata *nd)
{
J
Josef 'Jeff' Sipek 已提交
490 491
	struct vfsmount *mnt;

492 493
	if (path[0] == '\0')
		return -ENOENT;
J
Josef 'Jeff' Sipek 已提交
494 495 496

	mnt = rpc_get_mount();
	if (IS_ERR(mnt)) {
497
		printk(KERN_WARNING "%s: %s failed to mount "
498
			       "pseudofilesystem \n", __FILE__, __func__);
J
Josef 'Jeff' Sipek 已提交
499
		return PTR_ERR(mnt);
500 501
	}

J
Josef 'Jeff' Sipek 已提交
502
	if (vfs_path_lookup(mnt->mnt_root, mnt, path, LOOKUP_PARENT, nd)) {
503
		printk(KERN_WARNING "%s: %s failed to find path %s\n",
504
				__FILE__, __func__, path);
505 506 507 508 509 510 511 512 513
		rpc_put_mount();
		return -ENOENT;
	}
	return 0;
}

static void
rpc_release_path(struct nameidata *nd)
{
J
Jan Blunck 已提交
514
	path_put(&nd->path);
515 516 517
	rpc_put_mount();
}

L
Linus Torvalds 已提交
518 519 520 521 522 523 524 525 526 527 528 529
static struct inode *
rpc_get_inode(struct super_block *sb, int mode)
{
	struct inode *inode = new_inode(sb);
	if (!inode)
		return NULL;
	inode->i_mode = mode;
	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
	switch(mode & S_IFMT) {
		case S_IFDIR:
			inode->i_fop = &simple_dir_operations;
			inode->i_op = &simple_dir_inode_operations;
530
			inc_nlink(inode);
L
Linus Torvalds 已提交
531 532 533 534 535 536 537 538 539
		default:
			break;
	}
	return inode;
}

/*
 * FIXME: This probably has races.
 */
540 541
static void rpc_depopulate(struct dentry *parent,
			   unsigned long start, unsigned long eof)
L
Linus Torvalds 已提交
542 543 544 545 546 547
{
	struct inode *dir = parent->d_inode;
	struct list_head *pos, *next;
	struct dentry *dentry, *dvec[10];
	int n = 0;

548
	mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD);
L
Linus Torvalds 已提交
549 550 551
repeat:
	spin_lock(&dcache_lock);
	list_for_each_safe(pos, next, &parent->d_subdirs) {
E
Eric Dumazet 已提交
552
		dentry = list_entry(pos, struct dentry, d_u.d_child);
T
Trond Myklebust 已提交
553 554 555 556
		if (!dentry->d_inode ||
				dentry->d_inode->i_ino < start ||
				dentry->d_inode->i_ino >= eof)
			continue;
L
Linus Torvalds 已提交
557 558 559 560 561 562 563 564 565 566 567 568 569 570 571
		spin_lock(&dentry->d_lock);
		if (!d_unhashed(dentry)) {
			dget_locked(dentry);
			__d_drop(dentry);
			spin_unlock(&dentry->d_lock);
			dvec[n++] = dentry;
			if (n == ARRAY_SIZE(dvec))
				break;
		} else
			spin_unlock(&dentry->d_lock);
	}
	spin_unlock(&dcache_lock);
	if (n) {
		do {
			dentry = dvec[--n];
T
Trond Myklebust 已提交
572
			if (S_ISREG(dentry->d_inode->i_mode))
L
Linus Torvalds 已提交
573
				simple_unlink(dir, dentry);
T
Trond Myklebust 已提交
574 575 576
			else if (S_ISDIR(dentry->d_inode->i_mode))
				simple_rmdir(dir, dentry);
			d_delete(dentry);
L
Linus Torvalds 已提交
577 578 579 580
			dput(dentry);
		} while (n);
		goto repeat;
	}
581
	mutex_unlock(&dir->i_mutex);
L
Linus Torvalds 已提交
582 583 584 585 586 587 588 589 590 591 592 593
}

static int
rpc_populate(struct dentry *parent,
		struct rpc_filelist *files,
		int start, int eof)
{
	struct inode *inode, *dir = parent->d_inode;
	void *private = RPC_I(dir)->private;
	struct dentry *dentry;
	int mode, i;

594
	mutex_lock(&dir->i_mutex);
L
Linus Torvalds 已提交
595 596 597 598
	for (i = start; i < eof; i++) {
		dentry = d_alloc_name(parent, files[i].name);
		if (!dentry)
			goto out_bad;
T
Trond Myklebust 已提交
599
		dentry->d_op = &rpc_dentry_operations;
L
Linus Torvalds 已提交
600 601 602 603 604 605 606 607 608 609 610 611
		mode = files[i].mode;
		inode = rpc_get_inode(dir->i_sb, mode);
		if (!inode) {
			dput(dentry);
			goto out_bad;
		}
		inode->i_ino = i;
		if (files[i].i_fop)
			inode->i_fop = files[i].i_fop;
		if (private)
			rpc_inode_setowner(inode, private);
		if (S_ISDIR(mode))
612
			inc_nlink(dir);
L
Linus Torvalds 已提交
613
		d_add(dentry, inode);
614
		fsnotify_create(dir, dentry);
L
Linus Torvalds 已提交
615
	}
616
	mutex_unlock(&dir->i_mutex);
L
Linus Torvalds 已提交
617 618
	return 0;
out_bad:
619
	mutex_unlock(&dir->i_mutex);
L
Linus Torvalds 已提交
620
	printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
621
			__FILE__, __func__, parent->d_name.name);
L
Linus Torvalds 已提交
622 623 624
	return -ENOMEM;
}

625 626
static int
__rpc_mkdir(struct inode *dir, struct dentry *dentry)
L
Linus Torvalds 已提交
627 628
{
	struct inode *inode;
629

630
	inode = rpc_get_inode(dir->i_sb, S_IFDIR | S_IRUGO | S_IXUGO);
631 632 633 634
	if (!inode)
		goto out_err;
	inode->i_ino = iunique(dir->i_sb, 100);
	d_instantiate(dentry, inode);
635
	inc_nlink(dir);
636
	fsnotify_mkdir(dir, dentry);
637 638 639
	return 0;
out_err:
	printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
640
			__FILE__, __func__, dentry->d_name.name);
641 642 643 644 645 646
	return -ENOMEM;
}

static int
__rpc_rmdir(struct inode *dir, struct dentry *dentry)
{
L
Linus Torvalds 已提交
647
	int error;
T
Trond Myklebust 已提交
648 649 650 651
	error = simple_rmdir(dir, dentry);
	if (!error)
		d_delete(dentry);
	return error;
652
}
L
Linus Torvalds 已提交
653

654
static struct dentry *
655
rpc_lookup_create(struct dentry *parent, const char *name, int len, int exclusive)
656
{
657
	struct inode *dir = parent->d_inode;
658
	struct dentry *dentry;
659

660
	mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
661
	dentry = lookup_one_len(name, parent, len);
L
Linus Torvalds 已提交
662
	if (IS_ERR(dentry))
663
		goto out_err;
T
Trond Myklebust 已提交
664 665 666
	if (!dentry->d_inode)
		dentry->d_op = &rpc_dentry_operations;
	else if (exclusive) {
667
		dput(dentry);
L
Linus Torvalds 已提交
668
		dentry = ERR_PTR(-EEXIST);
669
		goto out_err;
L
Linus Torvalds 已提交
670
	}
671 672
	return dentry;
out_err:
673
	mutex_unlock(&dir->i_mutex);
674 675 676 677 678 679 680 681 682 683 684
	return dentry;
}

static struct dentry *
rpc_lookup_negative(char *path, struct nameidata *nd)
{
	struct dentry *dentry;
	int error;

	if ((error = rpc_lookup_parent(path, nd)) != 0)
		return ERR_PTR(error);
685 686
	dentry = rpc_lookup_create(nd->path.dentry, nd->last.name, nd->last.len,
				   1);
687 688
	if (IS_ERR(dentry))
		rpc_release_path(nd);
689 690
	return dentry;
}
691

692 693 694
/**
 * rpc_mkdir - Create a new directory in rpc_pipefs
 * @path: path from the rpc_pipefs root to the new directory
695
 * @rpc_client: rpc client to associate with this directory
696 697 698 699 700 701
 *
 * This creates a directory at the given @path associated with
 * @rpc_clnt, which will contain a file named "info" with some basic
 * information about the client, together with any "pipes" that may
 * later be created using rpc_mkpipe().
 */
702 703 704 705 706 707 708 709 710 711 712
struct dentry *
rpc_mkdir(char *path, struct rpc_clnt *rpc_client)
{
	struct nameidata nd;
	struct dentry *dentry;
	struct inode *dir;
	int error;

	dentry = rpc_lookup_negative(path, &nd);
	if (IS_ERR(dentry))
		return dentry;
713
	dir = nd.path.dentry->d_inode;
714 715 716
	if ((error = __rpc_mkdir(dir, dentry)) != 0)
		goto err_dput;
	RPC_I(dentry->d_inode)->private = rpc_client;
L
Linus Torvalds 已提交
717 718 719
	error = rpc_populate(dentry, authfiles,
			RPCAUTH_info, RPCAUTH_EOF);
	if (error)
720
		goto err_depopulate;
721
	dget(dentry);
722
out:
723
	mutex_unlock(&dir->i_mutex);
724
	rpc_release_path(&nd);
725
	return dentry;
726
err_depopulate:
T
Trond Myklebust 已提交
727
	rpc_depopulate(dentry, RPCAUTH_info, RPCAUTH_EOF);
728 729 730 731
	__rpc_rmdir(dir, dentry);
err_dput:
	dput(dentry);
	printk(KERN_WARNING "%s: %s() failed to create directory %s (errno = %d)\n",
732
			__FILE__, __func__, path, error);
733 734
	dentry = ERR_PTR(error);
	goto out;
L
Linus Torvalds 已提交
735 736
}

737 738 739 740
/**
 * rpc_rmdir - Remove a directory created with rpc_mkdir()
 * @dentry: directory to remove
 */
741
int
T
Trond Myklebust 已提交
742
rpc_rmdir(struct dentry *dentry)
L
Linus Torvalds 已提交
743
{
T
Trond Myklebust 已提交
744
	struct dentry *parent;
745 746
	struct inode *dir;
	int error;
747

T
Trond Myklebust 已提交
748 749
	parent = dget_parent(dentry);
	dir = parent->d_inode;
750
	mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
T
Trond Myklebust 已提交
751
	rpc_depopulate(dentry, RPCAUTH_info, RPCAUTH_EOF);
752 753
	error = __rpc_rmdir(dir, dentry);
	dput(dentry);
754
	mutex_unlock(&dir->i_mutex);
T
Trond Myklebust 已提交
755
	dput(parent);
756
	return error;
L
Linus Torvalds 已提交
757 758
}

759 760 761 762 763 764
/**
 * rpc_mkpipe - make an rpc_pipefs file for kernel<->userspace communication
 * @parent: dentry of directory to create new "pipe" in
 * @name: name of pipe
 * @private: private data to associate with the pipe, for the caller's use
 * @ops: operations defining the behavior of the pipe: upcall, downcall,
765
 *	release_pipe, open_pipe, and destroy_msg.
766
 * @flags: rpc_inode flags
767 768 769 770 771 772 773 774 775 776 777 778
 *
 * Data is made available for userspace to read by calls to
 * rpc_queue_upcall().  The actual reads will result in calls to
 * @ops->upcall, which will be called with the file pointer,
 * message, and userspace buffer to copy to.
 *
 * Writes can come at any time, and do not necessarily have to be
 * responses to upcalls.  They will result in calls to @msg->downcall.
 *
 * The @private argument passed here will be available to all these methods
 * from the file pointer, via RPC_I(file->f_dentry->d_inode)->private.
 */
779 780 781
struct dentry *rpc_mkpipe(struct dentry *parent, const char *name,
			  void *private, const struct rpc_pipe_ops *ops,
			  int flags)
L
Linus Torvalds 已提交
782 783
{
	struct dentry *dentry;
784
	struct inode *dir, *inode;
L
Linus Torvalds 已提交
785 786
	struct rpc_inode *rpci;

787
	dentry = rpc_lookup_create(parent, name, strlen(name), 0);
L
Linus Torvalds 已提交
788
	if (IS_ERR(dentry))
789
		return dentry;
790
	dir = parent->d_inode;
791 792 793 794 795 796 797 798
	if (dentry->d_inode) {
		rpci = RPC_I(dentry->d_inode);
		if (rpci->private != private ||
				rpci->ops != ops ||
				rpci->flags != flags) {
			dput (dentry);
			dentry = ERR_PTR(-EBUSY);
		}
799
		rpci->nkern_readwriters++;
800 801
		goto out;
	}
802
	inode = rpc_get_inode(dir->i_sb, S_IFIFO | S_IRUSR | S_IWUSR);
803 804
	if (!inode)
		goto err_dput;
L
Linus Torvalds 已提交
805 806
	inode->i_ino = iunique(dir->i_sb, 100);
	inode->i_fop = &rpc_pipe_fops;
807
	d_instantiate(dentry, inode);
L
Linus Torvalds 已提交
808 809 810 811
	rpci = RPC_I(inode);
	rpci->private = private;
	rpci->flags = flags;
	rpci->ops = ops;
812
	rpci->nkern_readwriters = 1;
813
	fsnotify_create(dir, dentry);
814
	dget(dentry);
815
out:
816
	mutex_unlock(&dir->i_mutex);
817
	return dentry;
818
err_dput:
L
Linus Torvalds 已提交
819
	dput(dentry);
820
	dentry = ERR_PTR(-ENOMEM);
821
	printk(KERN_WARNING "%s: %s() failed to create pipe %s/%s (errno = %d)\n",
822
			__FILE__, __func__, parent->d_name.name, name,
823
			-ENOMEM);
824
	goto out;
L
Linus Torvalds 已提交
825
}
826
EXPORT_SYMBOL_GPL(rpc_mkpipe);
L
Linus Torvalds 已提交
827

828 829 830 831 832 833 834 835
/**
 * rpc_unlink - remove a pipe
 * @dentry: dentry for the pipe, as returned from rpc_mkpipe
 *
 * After this call, lookups will no longer find the pipe, and any
 * attempts to read or write using preexisting opens of the pipe will
 * return -EPIPE.
 */
836
int
837
rpc_unlink(struct dentry *dentry)
L
Linus Torvalds 已提交
838
{
839
	struct dentry *parent;
840
	struct inode *dir;
841
	int error = 0;
L
Linus Torvalds 已提交
842

843 844
	parent = dget_parent(dentry);
	dir = parent->d_inode;
845
	mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
846 847 848 849 850 851
	if (--RPC_I(dentry->d_inode)->nkern_readwriters == 0) {
		rpc_close_pipes(dentry->d_inode);
		error = simple_unlink(dir, dentry);
		if (!error)
			d_delete(dentry);
	}
852
	dput(dentry);
853
	mutex_unlock(&dir->i_mutex);
854
	dput(parent);
855
	return error;
L
Linus Torvalds 已提交
856
}
857
EXPORT_SYMBOL_GPL(rpc_unlink);
L
Linus Torvalds 已提交
858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899

/*
 * populate the filesystem
 */
static struct super_operations s_ops = {
	.alloc_inode	= rpc_alloc_inode,
	.destroy_inode	= rpc_destroy_inode,
	.statfs		= simple_statfs,
};

#define RPCAUTH_GSSMAGIC 0x67596969

static int
rpc_fill_super(struct super_block *sb, void *data, int silent)
{
	struct inode *inode;
	struct dentry *root;

	sb->s_blocksize = PAGE_CACHE_SIZE;
	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
	sb->s_magic = RPCAUTH_GSSMAGIC;
	sb->s_op = &s_ops;
	sb->s_time_gran = 1;

	inode = rpc_get_inode(sb, S_IFDIR | 0755);
	if (!inode)
		return -ENOMEM;
	root = d_alloc_root(inode);
	if (!root) {
		iput(inode);
		return -ENOMEM;
	}
	if (rpc_populate(root, files, RPCAUTH_Root + 1, RPCAUTH_RootEOF))
		goto out;
	sb->s_root = root;
	return 0;
out:
	d_genocide(root);
	dput(root);
	return -ENOMEM;
}

900
static int
L
Linus Torvalds 已提交
901
rpc_get_sb(struct file_system_type *fs_type,
902
		int flags, const char *dev_name, void *data, struct vfsmount *mnt)
L
Linus Torvalds 已提交
903
{
904
	return get_sb_single(fs_type, flags, data, rpc_fill_super, mnt);
L
Linus Torvalds 已提交
905 906 907 908 909 910 911 912 913 914
}

static struct file_system_type rpc_pipe_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "rpc_pipefs",
	.get_sb		= rpc_get_sb,
	.kill_sb	= kill_litter_super,
};

static void
915
init_once(void *foo)
L
Linus Torvalds 已提交
916 917 918
{
	struct rpc_inode *rpci = (struct rpc_inode *) foo;

C
Christoph Lameter 已提交
919 920 921 922 923
	inode_init_once(&rpci->vfs_inode);
	rpci->private = NULL;
	rpci->nreaders = 0;
	rpci->nwriters = 0;
	INIT_LIST_HEAD(&rpci->in_upcall);
924
	INIT_LIST_HEAD(&rpci->in_downcall);
C
Christoph Lameter 已提交
925 926 927 928 929 930
	INIT_LIST_HEAD(&rpci->pipe);
	rpci->pipelen = 0;
	init_waitqueue_head(&rpci->waitq);
	INIT_DELAYED_WORK(&rpci->queue_timeout,
			    rpc_timeout_upcall_queue);
	rpci->ops = NULL;
L
Linus Torvalds 已提交
931 932 933 934
}

int register_rpc_pipefs(void)
{
935 936
	int err;

L
Linus Torvalds 已提交
937
	rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
938 939 940
				sizeof(struct rpc_inode),
				0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
						SLAB_MEM_SPREAD),
941
				init_once);
L
Linus Torvalds 已提交
942 943
	if (!rpc_inode_cachep)
		return -ENOMEM;
944 945 946 947 948 949
	err = register_filesystem(&rpc_pipe_fs_type);
	if (err) {
		kmem_cache_destroy(rpc_inode_cachep);
		return err;
	}

L
Linus Torvalds 已提交
950 951 952 953 954
	return 0;
}

void unregister_rpc_pipefs(void)
{
955
	kmem_cache_destroy(rpc_inode_cachep);
L
Linus Torvalds 已提交
956 957
	unregister_filesystem(&rpc_pipe_fs_type);
}