97be3f7fed4481cba7d57c24d89d3338b2ad8030
[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/module.h>
12 #include <linux/slab.h>
13 #include <linux/string.h>
14 #include <linux/pagemap.h>
15 #include <linux/mount.h>
16 #include <linux/namei.h>
17 #include <linux/dnotify.h>
18 #include <linux/kernel.h>
19
20 #include <asm/ioctls.h>
21 #include <linux/fs.h>
22 #include <linux/poll.h>
23 #include <linux/wait.h>
24 #include <linux/seq_file.h>
25
26 #include <linux/sunrpc/clnt.h>
27 #include <linux/workqueue.h>
28 #include <linux/sunrpc/rpc_pipe_fs.h>
29
30 static struct vfsmount *rpc_mount __read_mostly;
31 static int rpc_mount_count;
32
33 static struct file_system_type rpc_pipe_fs_type;
34
35
36 static kmem_cache_t *rpc_inode_cachep __read_mostly;
37
38 #define RPC_UPCALL_TIMEOUT (30*HZ)
39
40 static void rpc_purge_list(struct rpc_inode *rpci, struct list_head *head,
41                 void (*destroy_msg)(struct rpc_pipe_msg *), int err)
42 {
43         struct rpc_pipe_msg *msg;
44
45         if (list_empty(head))
46                 return;
47         do {
48                 msg = list_entry(head->next, struct rpc_pipe_msg, list);
49                 list_del(&msg->list);
50                 msg->errno = err;
51                 destroy_msg(msg);
52         } while (!list_empty(head));
53         wake_up(&rpci->waitq);
54 }
55
56 static void
57 rpc_timeout_upcall_queue(void *data)
58 {
59         LIST_HEAD(free_list);
60         struct rpc_inode *rpci = (struct rpc_inode *)data;
61         struct inode *inode = &rpci->vfs_inode;
62         void (*destroy_msg)(struct rpc_pipe_msg *);
63
64         spin_lock(&inode->i_lock);
65         if (rpci->ops == NULL) {
66                 spin_unlock(&inode->i_lock);
67                 return;
68         }
69         destroy_msg = rpci->ops->destroy_msg;
70         if (rpci->nreaders == 0) {
71                 list_splice_init(&rpci->pipe, &free_list);
72                 rpci->pipelen = 0;
73         }
74         spin_unlock(&inode->i_lock);
75         rpc_purge_list(rpci, &free_list, destroy_msg, -ETIMEDOUT);
76 }
77
78 int
79 rpc_queue_upcall(struct inode *inode, struct rpc_pipe_msg *msg)
80 {
81         struct rpc_inode *rpci = RPC_I(inode);
82         int res = -EPIPE;
83
84         spin_lock(&inode->i_lock);
85         if (rpci->ops == NULL)
86                 goto out;
87         if (rpci->nreaders) {
88                 list_add_tail(&msg->list, &rpci->pipe);
89                 rpci->pipelen += msg->len;
90                 res = 0;
91         } else if (rpci->flags & RPC_PIPE_WAIT_FOR_OPEN) {
92                 if (list_empty(&rpci->pipe))
93                         queue_delayed_work(rpciod_workqueue,
94                                         &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_workqueue(rpciod_workqueue);
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: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
331         seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO));
332         return 0;
333 }
334
335 static int
336 rpc_info_open(struct inode *inode, struct file *file)
337 {
338         struct rpc_clnt *clnt;
339         int ret = single_open(file, rpc_show_info, NULL);
340
341         if (!ret) {
342                 struct seq_file *m = file->private_data;
343                 mutex_lock(&inode->i_mutex);
344                 clnt = RPC_I(inode)->private;
345                 if (clnt) {
346                         atomic_inc(&clnt->cl_users);
347                         m->private = clnt;
348                 } else {
349                         single_release(inode, file);
350                         ret = -EINVAL;
351                 }
352                 mutex_unlock(&inode->i_mutex);
353         }
354         return ret;
355 }
356
357 static int
358 rpc_info_release(struct inode *inode, struct file *file)
359 {
360         struct seq_file *m = file->private_data;
361         struct rpc_clnt *clnt = (struct rpc_clnt *)m->private;
362
363         if (clnt)
364                 rpc_release_client(clnt);
365         return single_release(inode, file);
366 }
367
368 static struct file_operations rpc_info_operations = {
369         .owner          = THIS_MODULE,
370         .open           = rpc_info_open,
371         .read           = seq_read,
372         .llseek         = seq_lseek,
373         .release        = rpc_info_release,
374 };
375
376
377 /*
378  * We have a single directory with 1 node in it.
379  */
380 enum {
381         RPCAUTH_Root = 1,
382         RPCAUTH_lockd,
383         RPCAUTH_mount,
384         RPCAUTH_nfs,
385         RPCAUTH_portmap,
386         RPCAUTH_statd,
387         RPCAUTH_RootEOF
388 };
389
390 /*
391  * Description of fs contents.
392  */
393 struct rpc_filelist {
394         char *name;
395         const struct file_operations *i_fop;
396         int mode;
397 };
398
399 static struct rpc_filelist files[] = {
400         [RPCAUTH_lockd] = {
401                 .name = "lockd",
402                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
403         },
404         [RPCAUTH_mount] = {
405                 .name = "mount",
406                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
407         },
408         [RPCAUTH_nfs] = {
409                 .name = "nfs",
410                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
411         },
412         [RPCAUTH_portmap] = {
413                 .name = "portmap",
414                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
415         },
416         [RPCAUTH_statd] = {
417                 .name = "statd",
418                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
419         },
420 };
421
422 enum {
423         RPCAUTH_info = 2,
424         RPCAUTH_EOF
425 };
426
427 static struct rpc_filelist authfiles[] = {
428         [RPCAUTH_info] = {
429                 .name = "info",
430                 .i_fop = &rpc_info_operations,
431                 .mode = S_IFREG | S_IRUSR,
432         },
433 };
434
435 struct vfsmount *rpc_get_mount(void)
436 {
437         int err;
438
439         err = simple_pin_fs(&rpc_pipe_fs_type, &rpc_mount, &rpc_mount_count);
440         if (err != 0)
441                 return ERR_PTR(err);
442         return rpc_mount;
443 }
444
445 void rpc_put_mount(void)
446 {
447         simple_release_fs(&rpc_mount, &rpc_mount_count);
448 }
449
450 static int
451 rpc_lookup_parent(char *path, struct nameidata *nd)
452 {
453         if (path[0] == '\0')
454                 return -ENOENT;
455         nd->mnt = rpc_get_mount();
456         if (IS_ERR(nd->mnt)) {
457                 printk(KERN_WARNING "%s: %s failed to mount "
458                                "pseudofilesystem \n", __FILE__, __FUNCTION__);
459                 return PTR_ERR(nd->mnt);
460         }
461         mntget(nd->mnt);
462         nd->dentry = dget(rpc_mount->mnt_root);
463         nd->last_type = LAST_ROOT;
464         nd->flags = LOOKUP_PARENT;
465         nd->depth = 0;
466
467         if (path_walk(path, nd)) {
468                 printk(KERN_WARNING "%s: %s failed to find path %s\n",
469                                 __FILE__, __FUNCTION__, path);
470                 rpc_put_mount();
471                 return -ENOENT;
472         }
473         return 0;
474 }
475
476 static void
477 rpc_release_path(struct nameidata *nd)
478 {
479         path_release(nd);
480         rpc_put_mount();
481 }
482
483 static struct inode *
484 rpc_get_inode(struct super_block *sb, int mode)
485 {
486         struct inode *inode = new_inode(sb);
487         if (!inode)
488                 return NULL;
489         inode->i_mode = mode;
490         inode->i_uid = inode->i_gid = 0;
491         inode->i_blocks = 0;
492         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
493         switch(mode & S_IFMT) {
494                 case S_IFDIR:
495                         inode->i_fop = &simple_dir_operations;
496                         inode->i_op = &simple_dir_inode_operations;
497                         inc_nlink(inode);
498                 default:
499                         break;
500         }
501         return inode;
502 }
503
504 /*
505  * FIXME: This probably has races.
506  */
507 static void
508 rpc_depopulate(struct dentry *parent)
509 {
510         struct inode *dir = parent->d_inode;
511         struct list_head *pos, *next;
512         struct dentry *dentry, *dvec[10];
513         int n = 0;
514
515         mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD);
516 repeat:
517         spin_lock(&dcache_lock);
518         list_for_each_safe(pos, next, &parent->d_subdirs) {
519                 dentry = list_entry(pos, struct dentry, d_u.d_child);
520                 spin_lock(&dentry->d_lock);
521                 if (!d_unhashed(dentry)) {
522                         dget_locked(dentry);
523                         __d_drop(dentry);
524                         spin_unlock(&dentry->d_lock);
525                         dvec[n++] = dentry;
526                         if (n == ARRAY_SIZE(dvec))
527                                 break;
528                 } else
529                         spin_unlock(&dentry->d_lock);
530         }
531         spin_unlock(&dcache_lock);
532         if (n) {
533                 do {
534                         dentry = dvec[--n];
535                         if (dentry->d_inode) {
536                                 rpc_close_pipes(dentry->d_inode);
537                                 simple_unlink(dir, dentry);
538                         }
539                         inode_dir_notify(dir, DN_DELETE);
540                         dput(dentry);
541                 } while (n);
542                 goto repeat;
543         }
544         mutex_unlock(&dir->i_mutex);
545 }
546
547 static int
548 rpc_populate(struct dentry *parent,
549                 struct rpc_filelist *files,
550                 int start, int eof)
551 {
552         struct inode *inode, *dir = parent->d_inode;
553         void *private = RPC_I(dir)->private;
554         struct dentry *dentry;
555         int mode, i;
556
557         mutex_lock(&dir->i_mutex);
558         for (i = start; i < eof; i++) {
559                 dentry = d_alloc_name(parent, files[i].name);
560                 if (!dentry)
561                         goto out_bad;
562                 mode = files[i].mode;
563                 inode = rpc_get_inode(dir->i_sb, mode);
564                 if (!inode) {
565                         dput(dentry);
566                         goto out_bad;
567                 }
568                 inode->i_ino = i;
569                 if (files[i].i_fop)
570                         inode->i_fop = files[i].i_fop;
571                 if (private)
572                         rpc_inode_setowner(inode, private);
573                 if (S_ISDIR(mode))
574                         inc_nlink(dir);
575                 d_add(dentry, inode);
576         }
577         mutex_unlock(&dir->i_mutex);
578         return 0;
579 out_bad:
580         mutex_unlock(&dir->i_mutex);
581         printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
582                         __FILE__, __FUNCTION__, parent->d_name.name);
583         return -ENOMEM;
584 }
585
586 static int
587 __rpc_mkdir(struct inode *dir, struct dentry *dentry)
588 {
589         struct inode *inode;
590
591         inode = rpc_get_inode(dir->i_sb, S_IFDIR | S_IRUSR | S_IXUSR);
592         if (!inode)
593                 goto out_err;
594         inode->i_ino = iunique(dir->i_sb, 100);
595         d_instantiate(dentry, inode);
596         inc_nlink(dir);
597         inode_dir_notify(dir, DN_CREATE);
598         return 0;
599 out_err:
600         printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
601                         __FILE__, __FUNCTION__, dentry->d_name.name);
602         return -ENOMEM;
603 }
604
605 static int
606 __rpc_rmdir(struct inode *dir, struct dentry *dentry)
607 {
608         int error;
609
610         shrink_dcache_parent(dentry);
611         if (d_unhashed(dentry))
612                 return 0;
613         if ((error = simple_rmdir(dir, dentry)) != 0)
614                 return error;
615         if (!error) {
616                 inode_dir_notify(dir, DN_DELETE);
617                 d_drop(dentry);
618         }
619         return 0;
620 }
621
622 static struct dentry *
623 rpc_lookup_create(struct dentry *parent, const char *name, int len)
624 {
625         struct inode *dir = parent->d_inode;
626         struct dentry *dentry;
627
628         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
629         dentry = lookup_one_len(name, parent, len);
630         if (IS_ERR(dentry))
631                 goto out_err;
632         if (dentry->d_inode) {
633                 dput(dentry);
634                 dentry = ERR_PTR(-EEXIST);
635                 goto out_err;
636         }
637         return dentry;
638 out_err:
639         mutex_unlock(&dir->i_mutex);
640         return dentry;
641 }
642
643 static struct dentry *
644 rpc_lookup_negative(char *path, struct nameidata *nd)
645 {
646         struct dentry *dentry;
647         int error;
648
649         if ((error = rpc_lookup_parent(path, nd)) != 0)
650                 return ERR_PTR(error);
651         dentry = rpc_lookup_create(nd->dentry, nd->last.name, nd->last.len);
652         if (IS_ERR(dentry))
653                 rpc_release_path(nd);
654         return dentry;
655 }
656
657
658 struct dentry *
659 rpc_mkdir(char *path, struct rpc_clnt *rpc_client)
660 {
661         struct nameidata nd;
662         struct dentry *dentry;
663         struct inode *dir;
664         int error;
665
666         dentry = rpc_lookup_negative(path, &nd);
667         if (IS_ERR(dentry))
668                 return dentry;
669         dir = nd.dentry->d_inode;
670         if ((error = __rpc_mkdir(dir, dentry)) != 0)
671                 goto err_dput;
672         RPC_I(dentry->d_inode)->private = rpc_client;
673         error = rpc_populate(dentry, authfiles,
674                         RPCAUTH_info, RPCAUTH_EOF);
675         if (error)
676                 goto err_depopulate;
677         dget(dentry);
678 out:
679         mutex_unlock(&dir->i_mutex);
680         rpc_release_path(&nd);
681         return dentry;
682 err_depopulate:
683         rpc_depopulate(dentry);
684         __rpc_rmdir(dir, dentry);
685 err_dput:
686         dput(dentry);
687         printk(KERN_WARNING "%s: %s() failed to create directory %s (errno = %d)\n",
688                         __FILE__, __FUNCTION__, path, error);
689         dentry = ERR_PTR(error);
690         goto out;
691 }
692
693 int
694 rpc_rmdir(struct dentry *dentry)
695 {
696         struct dentry *parent;
697         struct inode *dir;
698         int error;
699
700         parent = dget_parent(dentry);
701         dir = parent->d_inode;
702         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
703         rpc_depopulate(dentry);
704         error = __rpc_rmdir(dir, dentry);
705         dput(dentry);
706         mutex_unlock(&dir->i_mutex);
707         dput(parent);
708         return error;
709 }
710
711 struct dentry *
712 rpc_mkpipe(struct dentry *parent, const char *name, void *private, struct rpc_pipe_ops *ops, int flags)
713 {
714         struct dentry *dentry;
715         struct inode *dir, *inode;
716         struct rpc_inode *rpci;
717
718         dentry = rpc_lookup_create(parent, name, strlen(name));
719         if (IS_ERR(dentry))
720                 return dentry;
721         dir = parent->d_inode;
722         inode = rpc_get_inode(dir->i_sb, S_IFIFO | S_IRUSR | S_IWUSR);
723         if (!inode)
724                 goto err_dput;
725         inode->i_ino = iunique(dir->i_sb, 100);
726         inode->i_fop = &rpc_pipe_fops;
727         d_instantiate(dentry, inode);
728         rpci = RPC_I(inode);
729         rpci->private = private;
730         rpci->flags = flags;
731         rpci->ops = ops;
732         inode_dir_notify(dir, DN_CREATE);
733         dget(dentry);
734 out:
735         mutex_unlock(&dir->i_mutex);
736         return dentry;
737 err_dput:
738         dput(dentry);
739         dentry = ERR_PTR(-ENOMEM);
740         printk(KERN_WARNING "%s: %s() failed to create pipe %s/%s (errno = %d)\n",
741                         __FILE__, __FUNCTION__, parent->d_name.name, name,
742                         -ENOMEM);
743         goto out;
744 }
745
746 int
747 rpc_unlink(struct dentry *dentry)
748 {
749         struct dentry *parent;
750         struct inode *dir;
751         int error = 0;
752
753         parent = dget_parent(dentry);
754         dir = parent->d_inode;
755         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
756         if (!d_unhashed(dentry)) {
757                 d_drop(dentry);
758                 if (dentry->d_inode) {
759                         rpc_close_pipes(dentry->d_inode);
760                         error = simple_unlink(dir, dentry);
761                 }
762                 inode_dir_notify(dir, DN_DELETE);
763         }
764         dput(dentry);
765         mutex_unlock(&dir->i_mutex);
766         dput(parent);
767         return error;
768 }
769
770 /*
771  * populate the filesystem
772  */
773 static struct super_operations s_ops = {
774         .alloc_inode    = rpc_alloc_inode,
775         .destroy_inode  = rpc_destroy_inode,
776         .statfs         = simple_statfs,
777 };
778
779 #define RPCAUTH_GSSMAGIC 0x67596969
780
781 static int
782 rpc_fill_super(struct super_block *sb, void *data, int silent)
783 {
784         struct inode *inode;
785         struct dentry *root;
786
787         sb->s_blocksize = PAGE_CACHE_SIZE;
788         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
789         sb->s_magic = RPCAUTH_GSSMAGIC;
790         sb->s_op = &s_ops;
791         sb->s_time_gran = 1;
792
793         inode = rpc_get_inode(sb, S_IFDIR | 0755);
794         if (!inode)
795                 return -ENOMEM;
796         root = d_alloc_root(inode);
797         if (!root) {
798                 iput(inode);
799                 return -ENOMEM;
800         }
801         if (rpc_populate(root, files, RPCAUTH_Root + 1, RPCAUTH_RootEOF))
802                 goto out;
803         sb->s_root = root;
804         return 0;
805 out:
806         d_genocide(root);
807         dput(root);
808         return -ENOMEM;
809 }
810
811 static int
812 rpc_get_sb(struct file_system_type *fs_type,
813                 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
814 {
815         return get_sb_single(fs_type, flags, data, rpc_fill_super, mnt);
816 }
817
818 static struct file_system_type rpc_pipe_fs_type = {
819         .owner          = THIS_MODULE,
820         .name           = "rpc_pipefs",
821         .get_sb         = rpc_get_sb,
822         .kill_sb        = kill_litter_super,
823 };
824
825 static void
826 init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
827 {
828         struct rpc_inode *rpci = (struct rpc_inode *) foo;
829
830         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
831             SLAB_CTOR_CONSTRUCTOR) {
832                 inode_init_once(&rpci->vfs_inode);
833                 rpci->private = NULL;
834                 rpci->nreaders = 0;
835                 rpci->nwriters = 0;
836                 INIT_LIST_HEAD(&rpci->in_upcall);
837                 INIT_LIST_HEAD(&rpci->pipe);
838                 rpci->pipelen = 0;
839                 init_waitqueue_head(&rpci->waitq);
840                 INIT_DELAYED_WORK(&rpci->queue_timeout,
841                                     rpc_timeout_upcall_queue, rpci);
842                 rpci->ops = NULL;
843         }
844 }
845
846 int register_rpc_pipefs(void)
847 {
848         rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
849                                 sizeof(struct rpc_inode),
850                                 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
851                                                 SLAB_MEM_SPREAD),
852                                 init_once, NULL);
853         if (!rpc_inode_cachep)
854                 return -ENOMEM;
855         register_filesystem(&rpc_pipe_fs_type);
856         return 0;
857 }
858
859 void unregister_rpc_pipefs(void)
860 {
861         kmem_cache_destroy(rpc_inode_cachep);
862         unregister_filesystem(&rpc_pipe_fs_type);
863 }