rpc_pipe.c 17.9 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 17 18 19 20 21 22 23 24 25 26 27 28 29 30
 *
 * Copyright (c) 2002, Trond Myklebust <trond.myklebust@fys.uio.no>
 *
 */
#include <linux/config.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/pagemap.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/dnotify.h>
#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>

31
static struct vfsmount *rpc_mount __read_mostly;
L
Linus Torvalds 已提交
32 33 34 35 36
static int rpc_mount_count;

static struct file_system_type rpc_pipe_fs_type;


37
static kmem_cache_t *rpc_inode_cachep __read_mostly;
L
Linus Torvalds 已提交
38 39 40 41

#define RPC_UPCALL_TIMEOUT (30*HZ)

static void
42
__rpc_purge_list(struct rpc_inode *rpci, struct list_head *head, int err)
L
Linus Torvalds 已提交
43 44
{
	struct rpc_pipe_msg *msg;
45
	void (*destroy_msg)(struct rpc_pipe_msg *);
L
Linus Torvalds 已提交
46

47 48 49
	destroy_msg = rpci->ops->destroy_msg;
	while (!list_empty(head)) {
		msg = list_entry(head->next, struct rpc_pipe_msg, list);
L
Linus Torvalds 已提交
50 51
		list_del_init(&msg->list);
		msg->errno = err;
52
		destroy_msg(msg);
L
Linus Torvalds 已提交
53
	}
54 55 56 57 58 59 60 61
}

static void
__rpc_purge_upcall(struct inode *inode, int err)
{
	struct rpc_inode *rpci = RPC_I(inode);

	__rpc_purge_list(rpci, &rpci->pipe, err);
L
Linus Torvalds 已提交
62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81
	rpci->pipelen = 0;
	wake_up(&rpci->waitq);
}

static void
rpc_timeout_upcall_queue(void *data)
{
	struct rpc_inode *rpci = (struct rpc_inode *)data;
	struct inode *inode = &rpci->vfs_inode;

	down(&inode->i_sem);
	if (rpci->nreaders == 0 && !list_empty(&rpci->pipe))
		__rpc_purge_upcall(inode, -ETIMEDOUT);
	up(&inode->i_sem);
}

int
rpc_queue_upcall(struct inode *inode, struct rpc_pipe_msg *msg)
{
	struct rpc_inode *rpci = RPC_I(inode);
82
	int res = -EPIPE;
L
Linus Torvalds 已提交
83 84

	down(&inode->i_sem);
85 86
	if (rpci->ops == NULL)
		goto out;
L
Linus Torvalds 已提交
87 88 89
	if (rpci->nreaders) {
		list_add_tail(&msg->list, &rpci->pipe);
		rpci->pipelen += msg->len;
90
		res = 0;
L
Linus Torvalds 已提交
91 92 93 94 95 96
	} else if (rpci->flags & RPC_PIPE_WAIT_FOR_OPEN) {
		if (list_empty(&rpci->pipe))
			schedule_delayed_work(&rpci->queue_timeout,
					RPC_UPCALL_TIMEOUT);
		list_add_tail(&msg->list, &rpci->pipe);
		rpci->pipelen += msg->len;
97 98 99
		res = 0;
	}
out:
L
Linus Torvalds 已提交
100 101 102 103 104
	up(&inode->i_sem);
	wake_up(&rpci->waitq);
	return res;
}

105 106 107 108 109 110
static inline void
rpc_inode_setowner(struct inode *inode, void *private)
{
	RPC_I(inode)->private = private;
}

L
Linus Torvalds 已提交
111 112 113 114 115 116 117 118 119 120
static void
rpc_close_pipes(struct inode *inode)
{
	struct rpc_inode *rpci = RPC_I(inode);

	cancel_delayed_work(&rpci->queue_timeout);
	flush_scheduled_work();
	down(&inode->i_sem);
	if (rpci->ops != NULL) {
		rpci->nreaders = 0;
121
		__rpc_purge_list(rpci, &rpci->in_upcall, -EPIPE);
L
Linus Torvalds 已提交
122 123 124 125 126 127
		__rpc_purge_upcall(inode, -EPIPE);
		rpci->nwriters = 0;
		if (rpci->ops->release_pipe)
			rpci->ops->release_pipe(inode);
		rpci->ops = NULL;
	}
128
	rpc_inode_setowner(inode, NULL);
L
Linus Torvalds 已提交
129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425
	up(&inode->i_sem);
}

static struct inode *
rpc_alloc_inode(struct super_block *sb)
{
	struct rpc_inode *rpci;
	rpci = (struct rpc_inode *)kmem_cache_alloc(rpc_inode_cachep, SLAB_KERNEL);
	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);
	int res = -ENXIO;

	down(&inode->i_sem);
	if (rpci->ops != NULL) {
		if (filp->f_mode & FMODE_READ)
			rpci->nreaders ++;
		if (filp->f_mode & FMODE_WRITE)
			rpci->nwriters ++;
		res = 0;
	}
	up(&inode->i_sem);
	return res;
}

static int
rpc_pipe_release(struct inode *inode, struct file *filp)
{
	struct rpc_inode *rpci = RPC_I(filp->f_dentry->d_inode);
	struct rpc_pipe_msg *msg;

	down(&inode->i_sem);
	if (rpci->ops == NULL)
		goto out;
	msg = (struct rpc_pipe_msg *)filp->private_data;
	if (msg != NULL) {
		msg->errno = -EPIPE;
		list_del_init(&msg->list);
		rpci->ops->destroy_msg(msg);
	}
	if (filp->f_mode & FMODE_WRITE)
		rpci->nwriters --;
	if (filp->f_mode & FMODE_READ)
		rpci->nreaders --;
	if (!rpci->nreaders)
		__rpc_purge_upcall(inode, -EPIPE);
	if (rpci->ops->release_pipe)
		rpci->ops->release_pipe(inode);
out:
	up(&inode->i_sem);
	return 0;
}

static ssize_t
rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
{
	struct inode *inode = filp->f_dentry->d_inode;
	struct rpc_inode *rpci = RPC_I(inode);
	struct rpc_pipe_msg *msg;
	int res = 0;

	down(&inode->i_sem);
	if (rpci->ops == NULL) {
		res = -EPIPE;
		goto out_unlock;
	}
	msg = filp->private_data;
	if (msg == NULL) {
		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;
		}
		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;
		list_del_init(&msg->list);
		rpci->ops->destroy_msg(msg);
	}
out_unlock:
	up(&inode->i_sem);
	return res;
}

static ssize_t
rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
{
	struct inode *inode = filp->f_dentry->d_inode;
	struct rpc_inode *rpci = RPC_I(inode);
	int res;

	down(&inode->i_sem);
	res = -EPIPE;
	if (rpci->ops != NULL)
		res = rpci->ops->downcall(filp, buf, len);
	up(&inode->i_sem);
	return res;
}

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

	rpci = RPC_I(filp->f_dentry->d_inode);
	poll_wait(filp, &rpci->waitq, wait);

	mask = POLLOUT | POLLWRNORM;
	if (rpci->ops == NULL)
		mask |= POLLERR | POLLHUP;
	if (!list_empty(&rpci->pipe))
		mask |= POLLIN | POLLRDNORM;
	return mask;
}

static int
rpc_pipe_ioctl(struct inode *ino, struct file *filp,
		unsigned int cmd, unsigned long arg)
{
	struct rpc_inode *rpci = RPC_I(filp->f_dentry->d_inode);
	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;
	}
}

static struct file_operations rpc_pipe_fops = {
	.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);
	seq_printf(m, "address: %u.%u.%u.%u\n",
			NIPQUAD(clnt->cl_xprt->addr.sin_addr.s_addr));
	seq_printf(m, "protocol: %s\n",
			clnt->cl_xprt->prot == IPPROTO_UDP ? "udp" : "tcp");
	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;
		down(&inode->i_sem);
		clnt = RPC_I(inode)->private;
		if (clnt) {
			atomic_inc(&clnt->cl_users);
			m->private = clnt;
		} else {
			single_release(inode, file);
			ret = -EINVAL;
		}
		up(&inode->i_sem);
	}
	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);
}

static struct file_operations rpc_info_operations = {
	.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,
	RPCAUTH_RootEOF
};

/*
 * Description of fs contents.
 */
struct rpc_filelist {
	char *name;
	struct file_operations *i_fop;
	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,
	},
};

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,
	},
};

static int
rpc_get_mount(void)
{
	return simple_pin_fs("rpc_pipefs", &rpc_mount, &rpc_mount_count);
}

static void
rpc_put_mount(void)
{
	simple_release_fs(&rpc_mount, &rpc_mount_count);
}

426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457
static int
rpc_lookup_parent(char *path, struct nameidata *nd)
{
	if (path[0] == '\0')
		return -ENOENT;
	if (rpc_get_mount()) {
		printk(KERN_WARNING "%s: %s failed to mount "
			       "pseudofilesystem \n", __FILE__, __FUNCTION__);
		return -ENODEV;
	}
	nd->mnt = mntget(rpc_mount);
	nd->dentry = dget(rpc_mount->mnt_root);
	nd->last_type = LAST_ROOT;
	nd->flags = LOOKUP_PARENT;
	nd->depth = 0;

	if (path_walk(path, nd)) {
		printk(KERN_WARNING "%s: %s failed to find path %s\n",
				__FILE__, __FUNCTION__, path);
		rpc_put_mount();
		return -ENOENT;
	}
	return 0;
}

static void
rpc_release_path(struct nameidata *nd)
{
	path_release(nd);
	rpc_put_mount();
}

L
Linus Torvalds 已提交
458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560
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_uid = inode->i_gid = 0;
	inode->i_blksize = PAGE_CACHE_SIZE;
	inode->i_blocks = 0;
	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;
			inode->i_nlink++;
		default:
			break;
	}
	return inode;
}

/*
 * FIXME: This probably has races.
 */
static void
rpc_depopulate(struct dentry *parent)
{
	struct inode *dir = parent->d_inode;
	struct list_head *pos, *next;
	struct dentry *dentry, *dvec[10];
	int n = 0;

	down(&dir->i_sem);
repeat:
	spin_lock(&dcache_lock);
	list_for_each_safe(pos, next, &parent->d_subdirs) {
		dentry = list_entry(pos, struct dentry, d_child);
		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];
			if (dentry->d_inode) {
				rpc_close_pipes(dentry->d_inode);
				simple_unlink(dir, dentry);
			}
			dput(dentry);
		} while (n);
		goto repeat;
	}
	up(&dir->i_sem);
}

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;

	down(&dir->i_sem);
	for (i = start; i < eof; i++) {
		dentry = d_alloc_name(parent, files[i].name);
		if (!dentry)
			goto out_bad;
		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))
			dir->i_nlink++;
		d_add(dentry, inode);
	}
	up(&dir->i_sem);
	return 0;
out_bad:
	up(&dir->i_sem);
	printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
			__FILE__, __FUNCTION__, parent->d_name.name);
	return -ENOMEM;
}

561 562
static int
__rpc_mkdir(struct inode *dir, struct dentry *dentry)
L
Linus Torvalds 已提交
563 564
{
	struct inode *inode;
565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583

	inode = rpc_get_inode(dir->i_sb, S_IFDIR | S_IRUSR | S_IXUSR);
	if (!inode)
		goto out_err;
	inode->i_ino = iunique(dir->i_sb, 100);
	d_instantiate(dentry, inode);
	dir->i_nlink++;
	inode_dir_notify(dir, DN_CREATE);
	rpc_get_mount();
	return 0;
out_err:
	printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
			__FILE__, __FUNCTION__, dentry->d_name.name);
	return -ENOMEM;
}

static int
__rpc_rmdir(struct inode *dir, struct dentry *dentry)
{
L
Linus Torvalds 已提交
584 585
	int error;

586
	shrink_dcache_parent(dentry);
587
	if (dentry->d_inode)
588 589 590 591 592 593 594 595 596 597
		rpc_close_pipes(dentry->d_inode);
	if ((error = simple_rmdir(dir, dentry)) != 0)
		return error;
	if (!error) {
		inode_dir_notify(dir, DN_DELETE);
		d_drop(dentry);
		rpc_put_mount();
	}
	return 0;
}
L
Linus Torvalds 已提交
598

599 600 601 602 603 604
static struct dentry *
rpc_lookup_negative(char *path, struct nameidata *nd)
{
	struct dentry *dentry;
	struct inode *dir;
	int error;
605

606 607 608
	if ((error = rpc_lookup_parent(path, nd)) != 0)
		return ERR_PTR(error);
	dir = nd->dentry->d_inode;
L
Linus Torvalds 已提交
609
	down(&dir->i_sem);
610
	dentry = lookup_hash(nd);
L
Linus Torvalds 已提交
611
	if (IS_ERR(dentry))
612
		goto out_err;
L
Linus Torvalds 已提交
613
	if (dentry->d_inode) {
614
		dput(dentry);
L
Linus Torvalds 已提交
615
		dentry = ERR_PTR(-EEXIST);
616
		goto out_err;
L
Linus Torvalds 已提交
617
	}
618 619
	return dentry;
out_err:
620
	up(&dir->i_sem);
621 622 623
	rpc_release_path(nd);
	return dentry;
}
624

L
Linus Torvalds 已提交
625

626 627 628 629 630 631 632 633 634 635 636 637 638 639 640
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;
	dir = nd.dentry->d_inode;
	if ((error = __rpc_mkdir(dir, dentry)) != 0)
		goto err_dput;
	RPC_I(dentry->d_inode)->private = rpc_client;
L
Linus Torvalds 已提交
641 642 643
	error = rpc_populate(dentry, authfiles,
			RPCAUTH_info, RPCAUTH_EOF);
	if (error)
644 645
		goto err_depopulate;
out:
646
	up(&dir->i_sem);
647
	rpc_release_path(&nd);
648
	return dentry;
649 650 651 652 653 654 655 656 657
err_depopulate:
	rpc_depopulate(dentry);
	__rpc_rmdir(dir, dentry);
err_dput:
	dput(dentry);
	printk(KERN_WARNING "%s: %s() failed to create directory %s (errno = %d)\n",
			__FILE__, __FUNCTION__, path, error);
	dentry = ERR_PTR(error);
	goto out;
L
Linus Torvalds 已提交
658 659
}

660 661
int
rpc_rmdir(char *path)
L
Linus Torvalds 已提交
662
{
663 664 665 666
	struct nameidata nd;
	struct dentry *dentry;
	struct inode *dir;
	int error;
667

668 669 670 671
	if ((error = rpc_lookup_parent(path, &nd)) != 0)
		return error;
	dir = nd.dentry->d_inode;
	down(&dir->i_sem);
672
	dentry = lookup_hash(&nd);
673 674 675
	if (IS_ERR(dentry)) {
		error = PTR_ERR(dentry);
		goto out_release;
676
	}
677 678 679 680 681 682 683
	rpc_depopulate(dentry);
	error = __rpc_rmdir(dir, dentry);
	dput(dentry);
out_release:
	up(&dir->i_sem);
	rpc_release_path(&nd);
	return error;
L
Linus Torvalds 已提交
684 685 686
}

struct dentry *
687
rpc_mkpipe(char *path, void *private, struct rpc_pipe_ops *ops, int flags)
L
Linus Torvalds 已提交
688
{
689
	struct nameidata nd;
L
Linus Torvalds 已提交
690
	struct dentry *dentry;
691
	struct inode *dir, *inode;
L
Linus Torvalds 已提交
692 693
	struct rpc_inode *rpci;

694
	dentry = rpc_lookup_negative(path, &nd);
L
Linus Torvalds 已提交
695
	if (IS_ERR(dentry))
696 697 698 699 700
		return dentry;
	dir = nd.dentry->d_inode;
	inode = rpc_get_inode(dir->i_sb, S_IFSOCK | S_IRUSR | S_IWUSR);
	if (!inode)
		goto err_dput;
L
Linus Torvalds 已提交
701 702
	inode->i_ino = iunique(dir->i_sb, 100);
	inode->i_fop = &rpc_pipe_fops;
703
	d_instantiate(dentry, inode);
L
Linus Torvalds 已提交
704 705 706 707 708
	rpci = RPC_I(inode);
	rpci->private = private;
	rpci->flags = flags;
	rpci->ops = ops;
	inode_dir_notify(dir, DN_CREATE);
709 710 711
out:
	up(&dir->i_sem);
	rpc_release_path(&nd);
L
Linus Torvalds 已提交
712
	return dentry;
713
err_dput:
L
Linus Torvalds 已提交
714
	dput(dentry);
715 716 717 718
	dentry = ERR_PTR(-ENOMEM);
	printk(KERN_WARNING "%s: %s() failed to create pipe %s (errno = %d)\n",
			__FILE__, __FUNCTION__, path, -ENOMEM);
	goto out;
L
Linus Torvalds 已提交
719 720
}

721 722
int
rpc_unlink(char *path)
L
Linus Torvalds 已提交
723
{
724 725 726 727
	struct nameidata nd;
	struct dentry *dentry;
	struct inode *dir;
	int error;
L
Linus Torvalds 已提交
728

729 730 731 732
	if ((error = rpc_lookup_parent(path, &nd)) != 0)
		return error;
	dir = nd.dentry->d_inode;
	down(&dir->i_sem);
733
	dentry = lookup_hash(&nd);
734 735 736 737 738
	if (IS_ERR(dentry)) {
		error = PTR_ERR(dentry);
		goto out_release;
	}
	d_drop(dentry);
L
Linus Torvalds 已提交
739 740
	if (dentry->d_inode) {
		rpc_close_pipes(dentry->d_inode);
741
		error = simple_unlink(dir, dentry);
L
Linus Torvalds 已提交
742
	}
743 744 745 746 747 748
	dput(dentry);
	inode_dir_notify(dir, DN_DELETE);
out_release:
	up(&dir->i_sem);
	rpc_release_path(&nd);
	return error;
L
Linus Torvalds 已提交
749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843
}

/*
 * 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;
}

static struct super_block *
rpc_get_sb(struct file_system_type *fs_type,
		int flags, const char *dev_name, void *data)
{
	return get_sb_single(fs_type, flags, data, rpc_fill_super);
}

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
init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
{
	struct rpc_inode *rpci = (struct rpc_inode *) foo;

	if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
	    SLAB_CTOR_CONSTRUCTOR) {
		inode_init_once(&rpci->vfs_inode);
		rpci->private = NULL;
		rpci->nreaders = 0;
		rpci->nwriters = 0;
		INIT_LIST_HEAD(&rpci->in_upcall);
		INIT_LIST_HEAD(&rpci->pipe);
		rpci->pipelen = 0;
		init_waitqueue_head(&rpci->waitq);
		INIT_WORK(&rpci->queue_timeout, rpc_timeout_upcall_queue, rpci);
		rpci->ops = NULL;
	}
}

int register_rpc_pipefs(void)
{
	rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
                                             sizeof(struct rpc_inode),
                                             0, SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT,
                                             init_once, NULL);
	if (!rpc_inode_cachep)
		return -ENOMEM;
	register_filesystem(&rpc_pipe_fs_type);
	return 0;
}

void unregister_rpc_pipefs(void)
{
	if (kmem_cache_destroy(rpc_inode_cachep))
		printk(KERN_WARNING "RPC: unable to free inode cache\n");
	unregister_filesystem(&rpc_pipe_fs_type);
}