[PATCH] cpuset memory spread: slab cache filesystems
[linux-2.6.git] / net / sunrpc / rpc_pipe.c
1 /*
2  * net/sunrpc/rpc_pipe.c
3  *
4  * Userland/kernel interface for rpcauth_gss.
5  * Code shamelessly plagiarized from fs/nfsd/nfsctl.c
6  * and fs/sysfs/inode.c
7  *
8  * Copyright (c) 2002, Trond Myklebust <trond.myklebust@fys.uio.no>
9  *
10  */
11 #include <linux/config.h>
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/namei.h>
18 #include <linux/dnotify.h>
19 #include <linux/kernel.h>
20
21 #include <asm/ioctls.h>
22 #include <linux/fs.h>
23 #include <linux/poll.h>
24 #include <linux/wait.h>
25 #include <linux/seq_file.h>
26
27 #include <linux/sunrpc/clnt.h>
28 #include <linux/workqueue.h>
29 #include <linux/sunrpc/rpc_pipe_fs.h>
30
31 static struct vfsmount *rpc_mount __read_mostly;
32 static int rpc_mount_count;
33
34 static struct file_system_type rpc_pipe_fs_type;
35
36
37 static kmem_cache_t *rpc_inode_cachep __read_mostly;
38
39 #define RPC_UPCALL_TIMEOUT (30*HZ)
40
41 static void rpc_purge_list(struct rpc_inode *rpci, struct list_head *head,
42                 void (*destroy_msg)(struct rpc_pipe_msg *), int err)
43 {
44         struct rpc_pipe_msg *msg;
45
46         if (list_empty(head))
47                 return;
48         do {
49                 msg = list_entry(head->next, struct rpc_pipe_msg, list);
50                 list_del(&msg->list);
51                 msg->errno = err;
52                 destroy_msg(msg);
53         } while (!list_empty(head));
54         wake_up(&rpci->waitq);
55 }
56
57 static void
58 rpc_timeout_upcall_queue(void *data)
59 {
60         LIST_HEAD(free_list);
61         struct rpc_inode *rpci = (struct rpc_inode *)data;
62         struct inode *inode = &rpci->vfs_inode;
63         void (*destroy_msg)(struct rpc_pipe_msg *);
64
65         spin_lock(&inode->i_lock);
66         if (rpci->ops == NULL) {
67                 spin_unlock(&inode->i_lock);
68                 return;
69         }
70         destroy_msg = rpci->ops->destroy_msg;
71         if (rpci->nreaders == 0) {
72                 list_splice_init(&rpci->pipe, &free_list);
73                 rpci->pipelen = 0;
74         }
75         spin_unlock(&inode->i_lock);
76         rpc_purge_list(rpci, &free_list, destroy_msg, -ETIMEDOUT);
77 }
78
79 int
80 rpc_queue_upcall(struct inode *inode, struct rpc_pipe_msg *msg)
81 {
82         struct rpc_inode *rpci = RPC_I(inode);
83         int res = -EPIPE;
84
85         spin_lock(&inode->i_lock);
86         if (rpci->ops == NULL)
87                 goto out;
88         if (rpci->nreaders) {
89                 list_add_tail(&msg->list, &rpci->pipe);
90                 rpci->pipelen += msg->len;
91                 res = 0;
92         } else if (rpci->flags & RPC_PIPE_WAIT_FOR_OPEN) {
93                 if (list_empty(&rpci->pipe))
94                         schedule_delayed_work(&rpci->queue_timeout,
95                                         RPC_UPCALL_TIMEOUT);
96                 list_add_tail(&msg->list, &rpci->pipe);
97                 rpci->pipelen += msg->len;
98                 res = 0;
99         }
100 out:
101         spin_unlock(&inode->i_lock);
102         wake_up(&rpci->waitq);
103         return res;
104 }
105
106 static inline void
107 rpc_inode_setowner(struct inode *inode, void *private)
108 {
109         RPC_I(inode)->private = private;
110 }
111
112 static void
113 rpc_close_pipes(struct inode *inode)
114 {
115         struct rpc_inode *rpci = RPC_I(inode);
116         struct rpc_pipe_ops *ops;
117
118         mutex_lock(&inode->i_mutex);
119         ops = rpci->ops;
120         if (ops != NULL) {
121                 LIST_HEAD(free_list);
122
123                 spin_lock(&inode->i_lock);
124                 rpci->nreaders = 0;
125                 list_splice_init(&rpci->in_upcall, &free_list);
126                 list_splice_init(&rpci->pipe, &free_list);
127                 rpci->pipelen = 0;
128                 rpci->ops = NULL;
129                 spin_unlock(&inode->i_lock);
130                 rpc_purge_list(rpci, &free_list, ops->destroy_msg, -EPIPE);
131                 rpci->nwriters = 0;
132                 if (ops->release_pipe)
133                         ops->release_pipe(inode);
134                 cancel_delayed_work(&rpci->queue_timeout);
135                 flush_scheduled_work();
136         }
137         rpc_inode_setowner(inode, NULL);
138         mutex_unlock(&inode->i_mutex);
139 }
140
141 static struct inode *
142 rpc_alloc_inode(struct super_block *sb)
143 {
144         struct rpc_inode *rpci;
145         rpci = (struct rpc_inode *)kmem_cache_alloc(rpc_inode_cachep, SLAB_KERNEL);
146         if (!rpci)
147                 return NULL;
148         return &rpci->vfs_inode;
149 }
150
151 static void
152 rpc_destroy_inode(struct inode *inode)
153 {
154         kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
155 }
156
157 static int
158 rpc_pipe_open(struct inode *inode, struct file *filp)
159 {
160         struct rpc_inode *rpci = RPC_I(inode);
161         int res = -ENXIO;
162
163         mutex_lock(&inode->i_mutex);
164         if (rpci->ops != NULL) {
165                 if (filp->f_mode & FMODE_READ)
166                         rpci->nreaders ++;
167                 if (filp->f_mode & FMODE_WRITE)
168                         rpci->nwriters ++;
169                 res = 0;
170         }
171         mutex_unlock(&inode->i_mutex);
172         return res;
173 }
174
175 static int
176 rpc_pipe_release(struct inode *inode, struct file *filp)
177 {
178         struct rpc_inode *rpci = RPC_I(inode);
179         struct rpc_pipe_msg *msg;
180
181         mutex_lock(&inode->i_mutex);
182         if (rpci->ops == NULL)
183                 goto out;
184         msg = (struct rpc_pipe_msg *)filp->private_data;
185         if (msg != NULL) {
186                 spin_lock(&inode->i_lock);
187                 msg->errno = -EAGAIN;
188                 list_del(&msg->list);
189                 spin_unlock(&inode->i_lock);
190                 rpci->ops->destroy_msg(msg);
191         }
192         if (filp->f_mode & FMODE_WRITE)
193                 rpci->nwriters --;
194         if (filp->f_mode & FMODE_READ) {
195                 rpci->nreaders --;
196                 if (rpci->nreaders == 0) {
197                         LIST_HEAD(free_list);
198                         spin_lock(&inode->i_lock);
199                         list_splice_init(&rpci->pipe, &free_list);
200                         rpci->pipelen = 0;
201                         spin_unlock(&inode->i_lock);
202                         rpc_purge_list(rpci, &free_list,
203                                         rpci->ops->destroy_msg, -EAGAIN);
204                 }
205         }
206         if (rpci->ops->release_pipe)
207                 rpci->ops->release_pipe(inode);
208 out:
209         mutex_unlock(&inode->i_mutex);
210         return 0;
211 }
212
213 static ssize_t
214 rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
215 {
216         struct inode *inode = filp->f_dentry->d_inode;
217         struct rpc_inode *rpci = RPC_I(inode);
218         struct rpc_pipe_msg *msg;
219         int res = 0;
220
221         mutex_lock(&inode->i_mutex);
222         if (rpci->ops == NULL) {
223                 res = -EPIPE;
224                 goto out_unlock;
225         }
226         msg = filp->private_data;
227         if (msg == NULL) {
228                 spin_lock(&inode->i_lock);
229                 if (!list_empty(&rpci->pipe)) {
230                         msg = list_entry(rpci->pipe.next,
231                                         struct rpc_pipe_msg,
232                                         list);
233                         list_move(&msg->list, &rpci->in_upcall);
234                         rpci->pipelen -= msg->len;
235                         filp->private_data = msg;
236                         msg->copied = 0;
237                 }
238                 spin_unlock(&inode->i_lock);
239                 if (msg == NULL)
240                         goto out_unlock;
241         }
242         /* NOTE: it is up to the callback to update msg->copied */
243         res = rpci->ops->upcall(filp, msg, buf, len);
244         if (res < 0 || msg->len == msg->copied) {
245                 filp->private_data = NULL;
246                 spin_lock(&inode->i_lock);
247                 list_del(&msg->list);
248                 spin_unlock(&inode->i_lock);
249                 rpci->ops->destroy_msg(msg);
250         }
251 out_unlock:
252         mutex_unlock(&inode->i_mutex);
253         return res;
254 }
255
256 static ssize_t
257 rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
258 {
259         struct inode *inode = filp->f_dentry->d_inode;
260         struct rpc_inode *rpci = RPC_I(inode);
261         int res;
262
263         mutex_lock(&inode->i_mutex);
264         res = -EPIPE;
265         if (rpci->ops != NULL)
266                 res = rpci->ops->downcall(filp, buf, len);
267         mutex_unlock(&inode->i_mutex);
268         return res;
269 }
270
271 static unsigned int
272 rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
273 {
274         struct rpc_inode *rpci;
275         unsigned int mask = 0;
276
277         rpci = RPC_I(filp->f_dentry->d_inode);
278         poll_wait(filp, &rpci->waitq, wait);
279
280         mask = POLLOUT | POLLWRNORM;
281         if (rpci->ops == NULL)
282                 mask |= POLLERR | POLLHUP;
283         if (!list_empty(&rpci->pipe))
284                 mask |= POLLIN | POLLRDNORM;
285         return mask;
286 }
287
288 static int
289 rpc_pipe_ioctl(struct inode *ino, struct file *filp,
290                 unsigned int cmd, unsigned long arg)
291 {
292         struct rpc_inode *rpci = RPC_I(filp->f_dentry->d_inode);
293         int len;
294
295         switch (cmd) {
296         case FIONREAD:
297                 if (rpci->ops == NULL)
298                         return -EPIPE;
299                 len = rpci->pipelen;
300                 if (filp->private_data) {
301                         struct rpc_pipe_msg *msg;
302                         msg = (struct rpc_pipe_msg *)filp->private_data;
303                         len += msg->len - msg->copied;
304                 }
305                 return put_user(len, (int __user *)arg);
306         default:
307                 return -EINVAL;
308         }
309 }
310
311 static struct file_operations rpc_pipe_fops = {
312         .owner          = THIS_MODULE,
313         .llseek         = no_llseek,
314         .read           = rpc_pipe_read,
315         .write          = rpc_pipe_write,
316         .poll           = rpc_pipe_poll,
317         .ioctl          = rpc_pipe_ioctl,
318         .open           = rpc_pipe_open,
319         .release        = rpc_pipe_release,
320 };
321
322 static int
323 rpc_show_info(struct seq_file *m, void *v)
324 {
325         struct rpc_clnt *clnt = m->private;
326
327         seq_printf(m, "RPC server: %s\n", clnt->cl_server);
328         seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_protname,
329                         clnt->cl_prog, clnt->cl_vers);
330         seq_printf(m, "address: %u.%u.%u.%u\n",
331                         NIPQUAD(clnt->cl_xprt->addr.sin_addr.s_addr));
332         seq_printf(m, "protocol: %s\n",
333                         clnt->cl_xprt->prot == IPPROTO_UDP ? "udp" : "tcp");
334         return 0;
335 }
336
337 static int
338 rpc_info_open(struct inode *inode, struct file *file)
339 {
340         struct rpc_clnt *clnt;
341         int ret = single_open(file, rpc_show_info, NULL);
342
343         if (!ret) {
344                 struct seq_file *m = file->private_data;
345                 mutex_lock(&inode->i_mutex);
346                 clnt = RPC_I(inode)->private;
347                 if (clnt) {
348                         atomic_inc(&clnt->cl_users);
349                         m->private = clnt;
350                 } else {
351                         single_release(inode, file);
352                         ret = -EINVAL;
353                 }
354                 mutex_unlock(&inode->i_mutex);
355         }
356         return ret;
357 }
358
359 static int
360 rpc_info_release(struct inode *inode, struct file *file)
361 {
362         struct seq_file *m = file->private_data;
363         struct rpc_clnt *clnt = (struct rpc_clnt *)m->private;
364
365         if (clnt)
366                 rpc_release_client(clnt);
367         return single_release(inode, file);
368 }
369
370 static struct file_operations rpc_info_operations = {
371         .owner          = THIS_MODULE,
372         .open           = rpc_info_open,
373         .read           = seq_read,
374         .llseek         = seq_lseek,
375         .release        = rpc_info_release,
376 };
377
378
379 /*
380  * We have a single directory with 1 node in it.
381  */
382 enum {
383         RPCAUTH_Root = 1,
384         RPCAUTH_lockd,
385         RPCAUTH_mount,
386         RPCAUTH_nfs,
387         RPCAUTH_portmap,
388         RPCAUTH_statd,
389         RPCAUTH_RootEOF
390 };
391
392 /*
393  * Description of fs contents.
394  */
395 struct rpc_filelist {
396         char *name;
397         struct file_operations *i_fop;
398         int mode;
399 };
400
401 static struct rpc_filelist files[] = {
402         [RPCAUTH_lockd] = {
403                 .name = "lockd",
404                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
405         },
406         [RPCAUTH_mount] = {
407                 .name = "mount",
408                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
409         },
410         [RPCAUTH_nfs] = {
411                 .name = "nfs",
412                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
413         },
414         [RPCAUTH_portmap] = {
415                 .name = "portmap",
416                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
417         },
418         [RPCAUTH_statd] = {
419                 .name = "statd",
420                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
421         },
422 };
423
424 enum {
425         RPCAUTH_info = 2,
426         RPCAUTH_EOF
427 };
428
429 static struct rpc_filelist authfiles[] = {
430         [RPCAUTH_info] = {
431                 .name = "info",
432                 .i_fop = &rpc_info_operations,
433                 .mode = S_IFREG | S_IRUSR,
434         },
435 };
436
437 static int
438 rpc_get_mount(void)
439 {
440         return simple_pin_fs("rpc_pipefs", &rpc_mount, &rpc_mount_count);
441 }
442
443 static void
444 rpc_put_mount(void)
445 {
446         simple_release_fs(&rpc_mount, &rpc_mount_count);
447 }
448
449 static int
450 rpc_lookup_parent(char *path, struct nameidata *nd)
451 {
452         if (path[0] == '\0')
453                 return -ENOENT;
454         if (rpc_get_mount()) {
455                 printk(KERN_WARNING "%s: %s failed to mount "
456                                "pseudofilesystem \n", __FILE__, __FUNCTION__);
457                 return -ENODEV;
458         }
459         nd->mnt = mntget(rpc_mount);
460         nd->dentry = dget(rpc_mount->mnt_root);
461         nd->last_type = LAST_ROOT;
462         nd->flags = LOOKUP_PARENT;
463         nd->depth = 0;
464
465         if (path_walk(path, nd)) {
466                 printk(KERN_WARNING "%s: %s failed to find path %s\n",
467                                 __FILE__, __FUNCTION__, path);
468                 rpc_put_mount();
469                 return -ENOENT;
470         }
471         return 0;
472 }
473
474 static void
475 rpc_release_path(struct nameidata *nd)
476 {
477         path_release(nd);
478         rpc_put_mount();
479 }
480
481 static struct inode *
482 rpc_get_inode(struct super_block *sb, int mode)
483 {
484         struct inode *inode = new_inode(sb);
485         if (!inode)
486                 return NULL;
487         inode->i_mode = mode;
488         inode->i_uid = inode->i_gid = 0;
489         inode->i_blksize = PAGE_CACHE_SIZE;
490         inode->i_blocks = 0;
491         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
492         switch(mode & S_IFMT) {
493                 case S_IFDIR:
494                         inode->i_fop = &simple_dir_operations;
495                         inode->i_op = &simple_dir_inode_operations;
496                         inode->i_nlink++;
497                 default:
498                         break;
499         }
500         return inode;
501 }
502
503 /*
504  * FIXME: This probably has races.
505  */
506 static void
507 rpc_depopulate(struct dentry *parent)
508 {
509         struct inode *dir = parent->d_inode;
510         struct list_head *pos, *next;
511         struct dentry *dentry, *dvec[10];
512         int n = 0;
513
514         mutex_lock(&dir->i_mutex);
515 repeat:
516         spin_lock(&dcache_lock);
517         list_for_each_safe(pos, next, &parent->d_subdirs) {
518                 dentry = list_entry(pos, struct dentry, d_u.d_child);
519                 spin_lock(&dentry->d_lock);
520                 if (!d_unhashed(dentry)) {
521                         dget_locked(dentry);
522                         __d_drop(dentry);
523                         spin_unlock(&dentry->d_lock);
524                         dvec[n++] = dentry;
525                         if (n == ARRAY_SIZE(dvec))
526                                 break;
527                 } else
528                         spin_unlock(&dentry->d_lock);
529         }
530         spin_unlock(&dcache_lock);
531         if (n) {
532                 do {
533                         dentry = dvec[--n];
534                         if (dentry->d_inode) {
535                                 rpc_close_pipes(dentry->d_inode);
536                                 simple_unlink(dir, dentry);
537                         }
538                         dput(dentry);
539                 } while (n);
540                 goto repeat;
541         }
542         mutex_unlock(&dir->i_mutex);
543 }
544
545 static int
546 rpc_populate(struct dentry *parent,
547                 struct rpc_filelist *files,
548                 int start, int eof)
549 {
550         struct inode *inode, *dir = parent->d_inode;
551         void *private = RPC_I(dir)->private;
552         struct dentry *dentry;
553         int mode, i;
554
555         mutex_lock(&dir->i_mutex);
556         for (i = start; i < eof; i++) {
557                 dentry = d_alloc_name(parent, files[i].name);
558                 if (!dentry)
559                         goto out_bad;
560                 mode = files[i].mode;
561                 inode = rpc_get_inode(dir->i_sb, mode);
562                 if (!inode) {
563                         dput(dentry);
564                         goto out_bad;
565                 }
566                 inode->i_ino = i;
567                 if (files[i].i_fop)
568                         inode->i_fop = files[i].i_fop;
569                 if (private)
570                         rpc_inode_setowner(inode, private);
571                 if (S_ISDIR(mode))
572                         dir->i_nlink++;
573                 d_add(dentry, inode);
574         }
575         mutex_unlock(&dir->i_mutex);
576         return 0;
577 out_bad:
578         mutex_unlock(&dir->i_mutex);
579         printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
580                         __FILE__, __FUNCTION__, parent->d_name.name);
581         return -ENOMEM;
582 }
583
584 static int
585 __rpc_mkdir(struct inode *dir, struct dentry *dentry)
586 {
587         struct inode *inode;
588
589         inode = rpc_get_inode(dir->i_sb, S_IFDIR | S_IRUSR | S_IXUSR);
590         if (!inode)
591                 goto out_err;
592         inode->i_ino = iunique(dir->i_sb, 100);
593         d_instantiate(dentry, inode);
594         dir->i_nlink++;
595         inode_dir_notify(dir, DN_CREATE);
596         rpc_get_mount();
597         return 0;
598 out_err:
599         printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
600                         __FILE__, __FUNCTION__, dentry->d_name.name);
601         return -ENOMEM;
602 }
603
604 static int
605 __rpc_rmdir(struct inode *dir, struct dentry *dentry)
606 {
607         int error;
608
609         shrink_dcache_parent(dentry);
610         if (dentry->d_inode)
611                 rpc_close_pipes(dentry->d_inode);
612         if ((error = simple_rmdir(dir, dentry)) != 0)
613                 return error;
614         if (!error) {
615                 inode_dir_notify(dir, DN_DELETE);
616                 d_drop(dentry);
617                 rpc_put_mount();
618         }
619         return 0;
620 }
621
622 static struct dentry *
623 rpc_lookup_negative(char *path, struct nameidata *nd)
624 {
625         struct dentry *dentry;
626         struct inode *dir;
627         int error;
628
629         if ((error = rpc_lookup_parent(path, nd)) != 0)
630                 return ERR_PTR(error);
631         dir = nd->dentry->d_inode;
632         mutex_lock(&dir->i_mutex);
633         dentry = lookup_one_len(nd->last.name, nd->dentry, nd->last.len);
634         if (IS_ERR(dentry))
635                 goto out_err;
636         if (dentry->d_inode) {
637                 dput(dentry);
638                 dentry = ERR_PTR(-EEXIST);
639                 goto out_err;
640         }
641         return dentry;
642 out_err:
643         mutex_unlock(&dir->i_mutex);
644         rpc_release_path(nd);
645         return dentry;
646 }
647
648
649 struct dentry *
650 rpc_mkdir(char *path, struct rpc_clnt *rpc_client)
651 {
652         struct nameidata nd;
653         struct dentry *dentry;
654         struct inode *dir;
655         int error;
656
657         dentry = rpc_lookup_negative(path, &nd);
658         if (IS_ERR(dentry))
659                 return dentry;
660         dir = nd.dentry->d_inode;
661         if ((error = __rpc_mkdir(dir, dentry)) != 0)
662                 goto err_dput;
663         RPC_I(dentry->d_inode)->private = rpc_client;
664         error = rpc_populate(dentry, authfiles,
665                         RPCAUTH_info, RPCAUTH_EOF);
666         if (error)
667                 goto err_depopulate;
668 out:
669         mutex_unlock(&dir->i_mutex);
670         rpc_release_path(&nd);
671         return dentry;
672 err_depopulate:
673         rpc_depopulate(dentry);
674         __rpc_rmdir(dir, dentry);
675 err_dput:
676         dput(dentry);
677         printk(KERN_WARNING "%s: %s() failed to create directory %s (errno = %d)\n",
678                         __FILE__, __FUNCTION__, path, error);
679         dentry = ERR_PTR(error);
680         goto out;
681 }
682
683 int
684 rpc_rmdir(char *path)
685 {
686         struct nameidata nd;
687         struct dentry *dentry;
688         struct inode *dir;
689         int error;
690
691         if ((error = rpc_lookup_parent(path, &nd)) != 0)
692                 return error;
693         dir = nd.dentry->d_inode;
694         mutex_lock(&dir->i_mutex);
695         dentry = lookup_one_len(nd.last.name, nd.dentry, nd.last.len);
696         if (IS_ERR(dentry)) {
697                 error = PTR_ERR(dentry);
698                 goto out_release;
699         }
700         rpc_depopulate(dentry);
701         error = __rpc_rmdir(dir, dentry);
702         dput(dentry);
703 out_release:
704         mutex_unlock(&dir->i_mutex);
705         rpc_release_path(&nd);
706         return error;
707 }
708
709 struct dentry *
710 rpc_mkpipe(char *path, void *private, struct rpc_pipe_ops *ops, int flags)
711 {
712         struct nameidata nd;
713         struct dentry *dentry;
714         struct inode *dir, *inode;
715         struct rpc_inode *rpci;
716
717         dentry = rpc_lookup_negative(path, &nd);
718         if (IS_ERR(dentry))
719                 return dentry;
720         dir = nd.dentry->d_inode;
721         inode = rpc_get_inode(dir->i_sb, S_IFSOCK | S_IRUSR | S_IWUSR);
722         if (!inode)
723                 goto err_dput;
724         inode->i_ino = iunique(dir->i_sb, 100);
725         inode->i_fop = &rpc_pipe_fops;
726         d_instantiate(dentry, inode);
727         rpci = RPC_I(inode);
728         rpci->private = private;
729         rpci->flags = flags;
730         rpci->ops = ops;
731         inode_dir_notify(dir, DN_CREATE);
732 out:
733         mutex_unlock(&dir->i_mutex);
734         rpc_release_path(&nd);
735         return dentry;
736 err_dput:
737         dput(dentry);
738         dentry = ERR_PTR(-ENOMEM);
739         printk(KERN_WARNING "%s: %s() failed to create pipe %s (errno = %d)\n",
740                         __FILE__, __FUNCTION__, path, -ENOMEM);
741         goto out;
742 }
743
744 int
745 rpc_unlink(char *path)
746 {
747         struct nameidata nd;
748         struct dentry *dentry;
749         struct inode *dir;
750         int error;
751
752         if ((error = rpc_lookup_parent(path, &nd)) != 0)
753                 return error;
754         dir = nd.dentry->d_inode;
755         mutex_lock(&dir->i_mutex);
756         dentry = lookup_one_len(nd.last.name, nd.dentry, nd.last.len);
757         if (IS_ERR(dentry)) {
758                 error = PTR_ERR(dentry);
759                 goto out_release;
760         }
761         d_drop(dentry);
762         if (dentry->d_inode) {
763                 rpc_close_pipes(dentry->d_inode);
764                 error = simple_unlink(dir, dentry);
765         }
766         dput(dentry);
767         inode_dir_notify(dir, DN_DELETE);
768 out_release:
769         mutex_unlock(&dir->i_mutex);
770         rpc_release_path(&nd);
771         return error;
772 }
773
774 /*
775  * populate the filesystem
776  */
777 static struct super_operations s_ops = {
778         .alloc_inode    = rpc_alloc_inode,
779         .destroy_inode  = rpc_destroy_inode,
780         .statfs         = simple_statfs,
781 };
782
783 #define RPCAUTH_GSSMAGIC 0x67596969
784
785 static int
786 rpc_fill_super(struct super_block *sb, void *data, int silent)
787 {
788         struct inode *inode;
789         struct dentry *root;
790
791         sb->s_blocksize = PAGE_CACHE_SIZE;
792         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
793         sb->s_magic = RPCAUTH_GSSMAGIC;
794         sb->s_op = &s_ops;
795         sb->s_time_gran = 1;
796
797         inode = rpc_get_inode(sb, S_IFDIR | 0755);
798         if (!inode)
799                 return -ENOMEM;
800         root = d_alloc_root(inode);
801         if (!root) {
802                 iput(inode);
803                 return -ENOMEM;
804         }
805         if (rpc_populate(root, files, RPCAUTH_Root + 1, RPCAUTH_RootEOF))
806                 goto out;
807         sb->s_root = root;
808         return 0;
809 out:
810         d_genocide(root);
811         dput(root);
812         return -ENOMEM;
813 }
814
815 static struct super_block *
816 rpc_get_sb(struct file_system_type *fs_type,
817                 int flags, const char *dev_name, void *data)
818 {
819         return get_sb_single(fs_type, flags, data, rpc_fill_super);
820 }
821
822 static struct file_system_type rpc_pipe_fs_type = {
823         .owner          = THIS_MODULE,
824         .name           = "rpc_pipefs",
825         .get_sb         = rpc_get_sb,
826         .kill_sb        = kill_litter_super,
827 };
828
829 static void
830 init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
831 {
832         struct rpc_inode *rpci = (struct rpc_inode *) foo;
833
834         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
835             SLAB_CTOR_CONSTRUCTOR) {
836                 inode_init_once(&rpci->vfs_inode);
837                 rpci->private = NULL;
838                 rpci->nreaders = 0;
839                 rpci->nwriters = 0;
840                 INIT_LIST_HEAD(&rpci->in_upcall);
841                 INIT_LIST_HEAD(&rpci->pipe);
842                 rpci->pipelen = 0;
843                 init_waitqueue_head(&rpci->waitq);
844                 INIT_WORK(&rpci->queue_timeout, rpc_timeout_upcall_queue, rpci);
845                 rpci->ops = NULL;
846         }
847 }
848
849 int register_rpc_pipefs(void)
850 {
851         rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
852                                              sizeof(struct rpc_inode),
853                                              0, SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
854                                              init_once, NULL);
855         if (!rpc_inode_cachep)
856                 return -ENOMEM;
857         register_filesystem(&rpc_pipe_fs_type);
858         return 0;
859 }
860
861 void unregister_rpc_pipefs(void)
862 {
863         if (kmem_cache_destroy(rpc_inode_cachep))
864                 printk(KERN_WARNING "RPC: unable to free inode cache\n");
865         unregister_filesystem(&rpc_pipe_fs_type);
866 }