rpc_pipe.c 19.4 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
}

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

85
	spin_lock(&inode->i_lock);
86 87
	if (rpci->ops == NULL)
		goto out;
L
Linus Torvalds 已提交
88 89 90
	if (rpci->nreaders) {
		list_add_tail(&msg->list, &rpci->pipe);
		rpci->pipelen += msg->len;
91
		res = 0;
L
Linus Torvalds 已提交
92 93
	} else if (rpci->flags & RPC_PIPE_WAIT_FOR_OPEN) {
		if (list_empty(&rpci->pipe))
94 95
			queue_delayed_work(rpciod_workqueue,
					&rpci->queue_timeout,
L
Linus Torvalds 已提交
96 97 98
					RPC_UPCALL_TIMEOUT);
		list_add_tail(&msg->list, &rpci->pipe);
		rpci->pipelen += msg->len;
99 100 101
		res = 0;
	}
out:
102
	spin_unlock(&inode->i_lock);
L
Linus Torvalds 已提交
103 104 105 106
	wake_up(&rpci->waitq);
	return res;
}

107 108 109 110 111 112
static inline void
rpc_inode_setowner(struct inode *inode, void *private)
{
	RPC_I(inode)->private = private;
}

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

119
	mutex_lock(&inode->i_mutex);
120 121 122 123 124
	ops = rpci->ops;
	if (ops != NULL) {
		LIST_HEAD(free_list);

		spin_lock(&inode->i_lock);
L
Linus Torvalds 已提交
125
		rpci->nreaders = 0;
126 127 128
		list_splice_init(&rpci->in_upcall, &free_list);
		list_splice_init(&rpci->pipe, &free_list);
		rpci->pipelen = 0;
L
Linus Torvalds 已提交
129
		rpci->ops = NULL;
130 131 132 133 134
		spin_unlock(&inode->i_lock);
		rpc_purge_list(rpci, &free_list, ops->destroy_msg, -EPIPE);
		rpci->nwriters = 0;
		if (ops->release_pipe)
			ops->release_pipe(inode);
135
		cancel_delayed_work_sync(&rpci->queue_timeout);
L
Linus Torvalds 已提交
136
	}
137
	rpc_inode_setowner(inode, NULL);
138
	mutex_unlock(&inode->i_mutex);
L
Linus Torvalds 已提交
139 140 141 142 143 144
}

static struct inode *
rpc_alloc_inode(struct super_block *sb)
{
	struct rpc_inode *rpci;
145
	rpci = (struct rpc_inode *)kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL);
L
Linus Torvalds 已提交
146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162
	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;

163
	mutex_lock(&inode->i_mutex);
L
Linus Torvalds 已提交
164 165 166 167 168 169 170
	if (rpci->ops != NULL) {
		if (filp->f_mode & FMODE_READ)
			rpci->nreaders ++;
		if (filp->f_mode & FMODE_WRITE)
			rpci->nwriters ++;
		res = 0;
	}
171
	mutex_unlock(&inode->i_mutex);
L
Linus Torvalds 已提交
172 173 174 175 176 177
	return res;
}

static int
rpc_pipe_release(struct inode *inode, struct file *filp)
{
178
	struct rpc_inode *rpci = RPC_I(inode);
L
Linus Torvalds 已提交
179 180
	struct rpc_pipe_msg *msg;

181
	mutex_lock(&inode->i_mutex);
L
Linus Torvalds 已提交
182 183 184 185
	if (rpci->ops == NULL)
		goto out;
	msg = (struct rpc_pipe_msg *)filp->private_data;
	if (msg != NULL) {
186
		spin_lock(&inode->i_lock);
187
		msg->errno = -EAGAIN;
188 189
		list_del(&msg->list);
		spin_unlock(&inode->i_lock);
L
Linus Torvalds 已提交
190 191 192 193
		rpci->ops->destroy_msg(msg);
	}
	if (filp->f_mode & FMODE_WRITE)
		rpci->nwriters --;
194
	if (filp->f_mode & FMODE_READ) {
L
Linus Torvalds 已提交
195
		rpci->nreaders --;
196 197 198 199 200 201 202 203 204 205
		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);
		}
	}
L
Linus Torvalds 已提交
206 207 208
	if (rpci->ops->release_pipe)
		rpci->ops->release_pipe(inode);
out:
209
	mutex_unlock(&inode->i_mutex);
L
Linus Torvalds 已提交
210 211 212 213 214 215
	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
216
	struct inode *inode = filp->f_path.dentry->d_inode;
L
Linus Torvalds 已提交
217 218 219 220
	struct rpc_inode *rpci = RPC_I(inode);
	struct rpc_pipe_msg *msg;
	int res = 0;

221
	mutex_lock(&inode->i_mutex);
L
Linus Torvalds 已提交
222 223 224 225 226 227
	if (rpci->ops == NULL) {
		res = -EPIPE;
		goto out_unlock;
	}
	msg = filp->private_data;
	if (msg == NULL) {
228
		spin_lock(&inode->i_lock);
L
Linus Torvalds 已提交
229 230 231 232 233 234 235 236 237
		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;
		}
238
		spin_unlock(&inode->i_lock);
L
Linus Torvalds 已提交
239 240 241 242 243 244 245
		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;
246 247 248
		spin_lock(&inode->i_lock);
		list_del(&msg->list);
		spin_unlock(&inode->i_lock);
L
Linus Torvalds 已提交
249 250 251
		rpci->ops->destroy_msg(msg);
	}
out_unlock:
252
	mutex_unlock(&inode->i_mutex);
L
Linus Torvalds 已提交
253 254 255 256 257 258
	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
259
	struct inode *inode = filp->f_path.dentry->d_inode;
L
Linus Torvalds 已提交
260 261 262
	struct rpc_inode *rpci = RPC_I(inode);
	int res;

263
	mutex_lock(&inode->i_mutex);
L
Linus Torvalds 已提交
264 265 266
	res = -EPIPE;
	if (rpci->ops != NULL)
		res = rpci->ops->downcall(filp, buf, len);
267
	mutex_unlock(&inode->i_mutex);
L
Linus Torvalds 已提交
268 269 270 271 272 273 274 275 276
	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
277
	rpci = RPC_I(filp->f_path.dentry->d_inode);
L
Linus Torvalds 已提交
278 279 280 281 282 283 284 285 286 287 288 289 290 291
	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)
{
J
Josef Sipek 已提交
292
	struct rpc_inode *rpci = RPC_I(filp->f_path.dentry->d_inode);
L
Linus Torvalds 已提交
293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310
	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;
	}
}

311
static const struct file_operations rpc_pipe_fops = {
L
Linus Torvalds 已提交
312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329
	.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);
330 331
	seq_printf(m, "address: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
	seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO));
332
	seq_printf(m, "port: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PORT));
L
Linus Torvalds 已提交
333 334 335 336 337 338 339 340 341 342 343
	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;
344
		mutex_lock(&inode->i_mutex);
L
Linus Torvalds 已提交
345 346
		clnt = RPC_I(inode)->private;
		if (clnt) {
347
			kref_get(&clnt->cl_kref);
L
Linus Torvalds 已提交
348 349 350 351 352
			m->private = clnt;
		} else {
			single_release(inode, file);
			ret = -EINVAL;
		}
353
		mutex_unlock(&inode->i_mutex);
L
Linus Torvalds 已提交
354 355 356 357 358 359 360 361 362 363 364 365 366 367 368
	}
	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);
}

369
static const struct file_operations rpc_info_operations = {
L
Linus Torvalds 已提交
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
	.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;
396
	const struct file_operations *i_fop;
L
Linus Torvalds 已提交
397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435
	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,
	},
};

436
struct vfsmount *rpc_get_mount(void)
L
Linus Torvalds 已提交
437
{
438 439
	int err;

440
	err = simple_pin_fs(&rpc_pipe_fs_type, &rpc_mount, &rpc_mount_count);
441 442 443
	if (err != 0)
		return ERR_PTR(err);
	return rpc_mount;
L
Linus Torvalds 已提交
444 445
}

446
void rpc_put_mount(void)
L
Linus Torvalds 已提交
447 448 449 450
{
	simple_release_fs(&rpc_mount, &rpc_mount_count);
}

T
Trond Myklebust 已提交
451 452 453 454 455 456 457 458 459
static int rpc_delete_dentry(struct dentry *dentry)
{
	return 1;
}

static struct dentry_operations rpc_dentry_operations = {
	.d_delete = rpc_delete_dentry,
};

460 461 462
static int
rpc_lookup_parent(char *path, struct nameidata *nd)
{
J
Josef 'Jeff' Sipek 已提交
463 464
	struct vfsmount *mnt;

465 466
	if (path[0] == '\0')
		return -ENOENT;
J
Josef 'Jeff' Sipek 已提交
467 468 469

	mnt = rpc_get_mount();
	if (IS_ERR(mnt)) {
470 471
		printk(KERN_WARNING "%s: %s failed to mount "
			       "pseudofilesystem \n", __FILE__, __FUNCTION__);
J
Josef 'Jeff' Sipek 已提交
472
		return PTR_ERR(mnt);
473 474
	}

J
Josef 'Jeff' Sipek 已提交
475
	if (vfs_path_lookup(mnt->mnt_root, mnt, path, LOOKUP_PARENT, nd)) {
476 477 478 479 480 481 482 483 484 485 486 487 488 489 490
		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
491 492 493 494 495 496 497 498 499 500 501 502 503 504
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_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;
505
			inc_nlink(inode);
L
Linus Torvalds 已提交
506 507 508 509 510 511 512 513 514 515
		default:
			break;
	}
	return inode;
}

/*
 * FIXME: This probably has races.
 */
static void
T
Trond Myklebust 已提交
516
rpc_depopulate(struct dentry *parent, int start, int eof)
L
Linus Torvalds 已提交
517 518 519 520 521 522
{
	struct inode *dir = parent->d_inode;
	struct list_head *pos, *next;
	struct dentry *dentry, *dvec[10];
	int n = 0;

523
	mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD);
L
Linus Torvalds 已提交
524 525 526
repeat:
	spin_lock(&dcache_lock);
	list_for_each_safe(pos, next, &parent->d_subdirs) {
E
Eric Dumazet 已提交
527
		dentry = list_entry(pos, struct dentry, d_u.d_child);
T
Trond Myklebust 已提交
528 529 530 531
		if (!dentry->d_inode ||
				dentry->d_inode->i_ino < start ||
				dentry->d_inode->i_ino >= eof)
			continue;
L
Linus Torvalds 已提交
532 533 534 535 536 537 538 539 540 541 542 543 544 545 546
		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
547
			if (S_ISREG(dentry->d_inode->i_mode))
L
Linus Torvalds 已提交
548
				simple_unlink(dir, dentry);
T
Trond Myklebust 已提交
549 550 551
			else if (S_ISDIR(dentry->d_inode->i_mode))
				simple_rmdir(dir, dentry);
			d_delete(dentry);
L
Linus Torvalds 已提交
552 553 554 555
			dput(dentry);
		} while (n);
		goto repeat;
	}
556
	mutex_unlock(&dir->i_mutex);
L
Linus Torvalds 已提交
557 558 559 560 561 562 563 564 565 566 567 568
}

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;

569
	mutex_lock(&dir->i_mutex);
L
Linus Torvalds 已提交
570 571 572 573
	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
574
		dentry->d_op = &rpc_dentry_operations;
L
Linus Torvalds 已提交
575 576 577 578 579 580 581 582 583 584 585 586
		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))
587
			inc_nlink(dir);
L
Linus Torvalds 已提交
588
		d_add(dentry, inode);
589
		fsnotify_create(dir, dentry);
L
Linus Torvalds 已提交
590
	}
591
	mutex_unlock(&dir->i_mutex);
L
Linus Torvalds 已提交
592 593
	return 0;
out_bad:
594
	mutex_unlock(&dir->i_mutex);
L
Linus Torvalds 已提交
595 596 597 598 599
	printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
			__FILE__, __FUNCTION__, parent->d_name.name);
	return -ENOMEM;
}

600 601
static int
__rpc_mkdir(struct inode *dir, struct dentry *dentry)
L
Linus Torvalds 已提交
602 603
{
	struct inode *inode;
604

605
	inode = rpc_get_inode(dir->i_sb, S_IFDIR | S_IRUGO | S_IXUGO);
606 607 608 609
	if (!inode)
		goto out_err;
	inode->i_ino = iunique(dir->i_sb, 100);
	d_instantiate(dentry, inode);
610
	inc_nlink(dir);
611
	fsnotify_mkdir(dir, dentry);
612 613 614 615 616 617 618 619 620 621
	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
622
	int error;
T
Trond Myklebust 已提交
623 624 625 626
	error = simple_rmdir(dir, dentry);
	if (!error)
		d_delete(dentry);
	return error;
627
}
L
Linus Torvalds 已提交
628

629
static struct dentry *
630
rpc_lookup_create(struct dentry *parent, const char *name, int len, int exclusive)
631
{
632
	struct inode *dir = parent->d_inode;
633
	struct dentry *dentry;
634

635
	mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
636
	dentry = lookup_one_len(name, parent, len);
L
Linus Torvalds 已提交
637
	if (IS_ERR(dentry))
638
		goto out_err;
T
Trond Myklebust 已提交
639 640 641
	if (!dentry->d_inode)
		dentry->d_op = &rpc_dentry_operations;
	else if (exclusive) {
642
		dput(dentry);
L
Linus Torvalds 已提交
643
		dentry = ERR_PTR(-EEXIST);
644
		goto out_err;
L
Linus Torvalds 已提交
645
	}
646 647
	return dentry;
out_err:
648
	mutex_unlock(&dir->i_mutex);
649 650 651 652 653 654 655 656 657 658 659
	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);
660
	dentry = rpc_lookup_create(nd->dentry, nd->last.name, nd->last.len, 1);
661 662
	if (IS_ERR(dentry))
		rpc_release_path(nd);
663 664
	return dentry;
}
665

L
Linus Torvalds 已提交
666

667 668 669 670 671 672 673 674 675 676 677 678 679 680 681
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
682 683 684
	error = rpc_populate(dentry, authfiles,
			RPCAUTH_info, RPCAUTH_EOF);
	if (error)
685
		goto err_depopulate;
686
	dget(dentry);
687
out:
688
	mutex_unlock(&dir->i_mutex);
689
	rpc_release_path(&nd);
690
	return dentry;
691
err_depopulate:
T
Trond Myklebust 已提交
692
	rpc_depopulate(dentry, RPCAUTH_info, RPCAUTH_EOF);
693 694 695 696 697 698 699
	__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
700 701
}

702
int
T
Trond Myklebust 已提交
703
rpc_rmdir(struct dentry *dentry)
L
Linus Torvalds 已提交
704
{
T
Trond Myklebust 已提交
705
	struct dentry *parent;
706 707
	struct inode *dir;
	int error;
708

T
Trond Myklebust 已提交
709 710
	parent = dget_parent(dentry);
	dir = parent->d_inode;
711
	mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
T
Trond Myklebust 已提交
712
	rpc_depopulate(dentry, RPCAUTH_info, RPCAUTH_EOF);
713 714
	error = __rpc_rmdir(dir, dentry);
	dput(dentry);
715
	mutex_unlock(&dir->i_mutex);
T
Trond Myklebust 已提交
716
	dput(parent);
717
	return error;
L
Linus Torvalds 已提交
718 719 720
}

struct dentry *
721
rpc_mkpipe(struct dentry *parent, const char *name, void *private, struct rpc_pipe_ops *ops, int flags)
L
Linus Torvalds 已提交
722 723
{
	struct dentry *dentry;
724
	struct inode *dir, *inode;
L
Linus Torvalds 已提交
725 726
	struct rpc_inode *rpci;

727
	dentry = rpc_lookup_create(parent, name, strlen(name), 0);
L
Linus Torvalds 已提交
728
	if (IS_ERR(dentry))
729
		return dentry;
730
	dir = parent->d_inode;
731 732 733 734 735 736 737 738
	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);
		}
739
		rpci->nkern_readwriters++;
740 741
		goto out;
	}
742
	inode = rpc_get_inode(dir->i_sb, S_IFIFO | S_IRUSR | S_IWUSR);
743 744
	if (!inode)
		goto err_dput;
L
Linus Torvalds 已提交
745 746
	inode->i_ino = iunique(dir->i_sb, 100);
	inode->i_fop = &rpc_pipe_fops;
747
	d_instantiate(dentry, inode);
L
Linus Torvalds 已提交
748 749 750 751
	rpci = RPC_I(inode);
	rpci->private = private;
	rpci->flags = flags;
	rpci->ops = ops;
752
	rpci->nkern_readwriters = 1;
753
	fsnotify_create(dir, dentry);
754
	dget(dentry);
755
out:
756
	mutex_unlock(&dir->i_mutex);
757
	return dentry;
758
err_dput:
L
Linus Torvalds 已提交
759
	dput(dentry);
760
	dentry = ERR_PTR(-ENOMEM);
761 762 763
	printk(KERN_WARNING "%s: %s() failed to create pipe %s/%s (errno = %d)\n",
			__FILE__, __FUNCTION__, parent->d_name.name, name,
			-ENOMEM);
764
	goto out;
L
Linus Torvalds 已提交
765 766
}

767
int
768
rpc_unlink(struct dentry *dentry)
L
Linus Torvalds 已提交
769
{
770
	struct dentry *parent;
771
	struct inode *dir;
772
	int error = 0;
L
Linus Torvalds 已提交
773

774 775
	parent = dget_parent(dentry);
	dir = parent->d_inode;
776
	mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
777 778 779 780 781 782
	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);
	}
783
	dput(dentry);
784
	mutex_unlock(&dir->i_mutex);
785
	dput(parent);
786
	return error;
L
Linus Torvalds 已提交
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
}

/*
 * 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;
}

830
static int
L
Linus Torvalds 已提交
831
rpc_get_sb(struct file_system_type *fs_type,
832
		int flags, const char *dev_name, void *data, struct vfsmount *mnt)
L
Linus Torvalds 已提交
833
{
834
	return get_sb_single(fs_type, flags, data, rpc_fill_super, mnt);
L
Linus Torvalds 已提交
835 836 837 838 839 840 841 842 843 844
}

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
845
init_once(struct kmem_cache * cachep, void *foo)
L
Linus Torvalds 已提交
846 847 848
{
	struct rpc_inode *rpci = (struct rpc_inode *) foo;

C
Christoph Lameter 已提交
849 850 851 852 853
	inode_init_once(&rpci->vfs_inode);
	rpci->private = NULL;
	rpci->nreaders = 0;
	rpci->nwriters = 0;
	INIT_LIST_HEAD(&rpci->in_upcall);
854
	INIT_LIST_HEAD(&rpci->in_downcall);
C
Christoph Lameter 已提交
855 856 857 858 859 860
	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
861 862 863 864
}

int register_rpc_pipefs(void)
{
865 866
	int err;

L
Linus Torvalds 已提交
867
	rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
868 869 870
				sizeof(struct rpc_inode),
				0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
						SLAB_MEM_SPREAD),
871
				init_once);
L
Linus Torvalds 已提交
872 873
	if (!rpc_inode_cachep)
		return -ENOMEM;
874 875 876 877 878 879
	err = register_filesystem(&rpc_pipe_fs_type);
	if (err) {
		kmem_cache_destroy(rpc_inode_cachep);
		return err;
	}

L
Linus Torvalds 已提交
880 881 882 883 884
	return 0;
}

void unregister_rpc_pipefs(void)
{
885
	kmem_cache_destroy(rpc_inode_cachep);
L
Linus Torvalds 已提交
886 887
	unregister_filesystem(&rpc_pipe_fs_type);
}