[PATCH] slab: remove kmem_cache_t
[linux-3.10.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 struct kmem_cache *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(struct work_struct *work)
58 {
59         LIST_HEAD(free_list);
60         struct rpc_inode *rpci =
61                 container_of(work, struct rpc_inode, queue_timeout.work);
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                         queue_delayed_work(rpciod_workqueue,
95                                         &rpci->queue_timeout,
96                                         RPC_UPCALL_TIMEOUT);
97                 list_add_tail(&msg->list, &rpci->pipe);
98                 rpci->pipelen += msg->len;
99                 res = 0;
100         }
101 out:
102         spin_unlock(&inode->i_lock);
103         wake_up(&rpci->waitq);
104         return res;
105 }
106
107 static inline void
108 rpc_inode_setowner(struct inode *inode, void *private)
109 {
110         RPC_I(inode)->private = private;
111 }
112
113 static void
114 rpc_close_pipes(struct inode *inode)
115 {
116         struct rpc_inode *rpci = RPC_I(inode);
117         struct rpc_pipe_ops *ops;
118
119         mutex_lock(&inode->i_mutex);
120         ops = rpci->ops;
121         if (ops != NULL) {
122                 LIST_HEAD(free_list);
123
124                 spin_lock(&inode->i_lock);
125                 rpci->nreaders = 0;
126                 list_splice_init(&rpci->in_upcall, &free_list);
127                 list_splice_init(&rpci->pipe, &free_list);
128                 rpci->pipelen = 0;
129                 rpci->ops = NULL;
130                 spin_unlock(&inode->i_lock);
131                 rpc_purge_list(rpci, &free_list, ops->destroy_msg, -EPIPE);
132                 rpci->nwriters = 0;
133                 if (ops->release_pipe)
134                         ops->release_pipe(inode);
135                 cancel_delayed_work(&rpci->queue_timeout);
136                 flush_workqueue(rpciod_workqueue);
137         }
138         rpc_inode_setowner(inode, NULL);
139         mutex_unlock(&inode->i_mutex);
140 }
141
142 static struct inode *
143 rpc_alloc_inode(struct super_block *sb)
144 {
145         struct rpc_inode *rpci;
146         rpci = (struct rpc_inode *)kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL);
147         if (!rpci)
148                 return NULL;
149         return &rpci->vfs_inode;
150 }
151
152 static void
153 rpc_destroy_inode(struct inode *inode)
154 {
155         kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
156 }
157
158 static int
159 rpc_pipe_open(struct inode *inode, struct file *filp)
160 {
161         struct rpc_inode *rpci = RPC_I(inode);
162         int res = -ENXIO;
163
164         mutex_lock(&inode->i_mutex);
165         if (rpci->ops != NULL) {
166                 if (filp->f_mode & FMODE_READ)
167                         rpci->nreaders ++;
168                 if (filp->f_mode & FMODE_WRITE)
169                         rpci->nwriters ++;
170                 res = 0;
171         }
172         mutex_unlock(&inode->i_mutex);
173         return res;
174 }
175
176 static int
177 rpc_pipe_release(struct inode *inode, struct file *filp)
178 {
179         struct rpc_inode *rpci = RPC_I(inode);
180         struct rpc_pipe_msg *msg;
181
182         mutex_lock(&inode->i_mutex);
183         if (rpci->ops == NULL)
184                 goto out;
185         msg = (struct rpc_pipe_msg *)filp->private_data;
186         if (msg != NULL) {
187                 spin_lock(&inode->i_lock);
188                 msg->errno = -EAGAIN;
189                 list_del(&msg->list);
190                 spin_unlock(&inode->i_lock);
191                 rpci->ops->destroy_msg(msg);
192         }
193         if (filp->f_mode & FMODE_WRITE)
194                 rpci->nwriters --;
195         if (filp->f_mode & FMODE_READ) {
196                 rpci->nreaders --;
197                 if (rpci->nreaders == 0) {
198                         LIST_HEAD(free_list);
199                         spin_lock(&inode->i_lock);
200                         list_splice_init(&rpci->pipe, &free_list);
201                         rpci->pipelen = 0;
202                         spin_unlock(&inode->i_lock);
203                         rpc_purge_list(rpci, &free_list,
204                                         rpci->ops->destroy_msg, -EAGAIN);
205                 }
206         }
207         if (rpci->ops->release_pipe)
208                 rpci->ops->release_pipe(inode);
209 out:
210         mutex_unlock(&inode->i_mutex);
211         return 0;
212 }
213
214 static ssize_t
215 rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
216 {
217         struct inode *inode = filp->f_dentry->d_inode;
218         struct rpc_inode *rpci = RPC_I(inode);
219         struct rpc_pipe_msg *msg;
220         int res = 0;
221
222         mutex_lock(&inode->i_mutex);
223         if (rpci->ops == NULL) {
224                 res = -EPIPE;
225                 goto out_unlock;
226         }
227         msg = filp->private_data;
228         if (msg == NULL) {
229                 spin_lock(&inode->i_lock);
230                 if (!list_empty(&rpci->pipe)) {
231                         msg = list_entry(rpci->pipe.next,
232                                         struct rpc_pipe_msg,
233                                         list);
234                         list_move(&msg->list, &rpci->in_upcall);
235                         rpci->pipelen -= msg->len;
236                         filp->private_data = msg;
237                         msg->copied = 0;
238                 }
239                 spin_unlock(&inode->i_lock);
240                 if (msg == NULL)
241                         goto out_unlock;
242         }
243         /* NOTE: it is up to the callback to update msg->copied */
244         res = rpci->ops->upcall(filp, msg, buf, len);
245         if (res < 0 || msg->len == msg->copied) {
246                 filp->private_data = NULL;
247                 spin_lock(&inode->i_lock);
248                 list_del(&msg->list);
249                 spin_unlock(&inode->i_lock);
250                 rpci->ops->destroy_msg(msg);
251         }
252 out_unlock:
253         mutex_unlock(&inode->i_mutex);
254         return res;
255 }
256
257 static ssize_t
258 rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
259 {
260         struct inode *inode = filp->f_dentry->d_inode;
261         struct rpc_inode *rpci = RPC_I(inode);
262         int res;
263
264         mutex_lock(&inode->i_mutex);
265         res = -EPIPE;
266         if (rpci->ops != NULL)
267                 res = rpci->ops->downcall(filp, buf, len);
268         mutex_unlock(&inode->i_mutex);
269         return res;
270 }
271
272 static unsigned int
273 rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
274 {
275         struct rpc_inode *rpci;
276         unsigned int mask = 0;
277
278         rpci = RPC_I(filp->f_dentry->d_inode);
279         poll_wait(filp, &rpci->waitq, wait);
280
281         mask = POLLOUT | POLLWRNORM;
282         if (rpci->ops == NULL)
283                 mask |= POLLERR | POLLHUP;
284         if (!list_empty(&rpci->pipe))
285                 mask |= POLLIN | POLLRDNORM;
286         return mask;
287 }
288
289 static int
290 rpc_pipe_ioctl(struct inode *ino, struct file *filp,
291                 unsigned int cmd, unsigned long arg)
292 {
293         struct rpc_inode *rpci = RPC_I(filp->f_dentry->d_inode);
294         int len;
295
296         switch (cmd) {
297         case FIONREAD:
298                 if (rpci->ops == NULL)
299                         return -EPIPE;
300                 len = rpci->pipelen;
301                 if (filp->private_data) {
302                         struct rpc_pipe_msg *msg;
303                         msg = (struct rpc_pipe_msg *)filp->private_data;
304                         len += msg->len - msg->copied;
305                 }
306                 return put_user(len, (int __user *)arg);
307         default:
308                 return -EINVAL;
309         }
310 }
311
312 static struct file_operations rpc_pipe_fops = {
313         .owner          = THIS_MODULE,
314         .llseek         = no_llseek,
315         .read           = rpc_pipe_read,
316         .write          = rpc_pipe_write,
317         .poll           = rpc_pipe_poll,
318         .ioctl          = rpc_pipe_ioctl,
319         .open           = rpc_pipe_open,
320         .release        = rpc_pipe_release,
321 };
322
323 static int
324 rpc_show_info(struct seq_file *m, void *v)
325 {
326         struct rpc_clnt *clnt = m->private;
327
328         seq_printf(m, "RPC server: %s\n", clnt->cl_server);
329         seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_protname,
330                         clnt->cl_prog, clnt->cl_vers);
331         seq_printf(m, "address: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
332         seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO));
333         return 0;
334 }
335
336 static int
337 rpc_info_open(struct inode *inode, struct file *file)
338 {
339         struct rpc_clnt *clnt;
340         int ret = single_open(file, rpc_show_info, NULL);
341
342         if (!ret) {
343                 struct seq_file *m = file->private_data;
344                 mutex_lock(&inode->i_mutex);
345                 clnt = RPC_I(inode)->private;
346                 if (clnt) {
347                         atomic_inc(&clnt->cl_users);
348                         m->private = clnt;
349                 } else {
350                         single_release(inode, file);
351                         ret = -EINVAL;
352                 }
353                 mutex_unlock(&inode->i_mutex);
354         }
355         return ret;
356 }
357
358 static int
359 rpc_info_release(struct inode *inode, struct file *file)
360 {
361         struct seq_file *m = file->private_data;
362         struct rpc_clnt *clnt = (struct rpc_clnt *)m->private;
363
364         if (clnt)
365                 rpc_release_client(clnt);
366         return single_release(inode, file);
367 }
368
369 static struct file_operations rpc_info_operations = {
370         .owner          = THIS_MODULE,
371         .open           = rpc_info_open,
372         .read           = seq_read,
373         .llseek         = seq_lseek,
374         .release        = rpc_info_release,
375 };
376
377
378 /*
379  * We have a single directory with 1 node in it.
380  */
381 enum {
382         RPCAUTH_Root = 1,
383         RPCAUTH_lockd,
384         RPCAUTH_mount,
385         RPCAUTH_nfs,
386         RPCAUTH_portmap,
387         RPCAUTH_statd,
388         RPCAUTH_RootEOF
389 };
390
391 /*
392  * Description of fs contents.
393  */
394 struct rpc_filelist {
395         char *name;
396         const struct file_operations *i_fop;
397         int mode;
398 };
399
400 static struct rpc_filelist files[] = {
401         [RPCAUTH_lockd] = {
402                 .name = "lockd",
403                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
404         },
405         [RPCAUTH_mount] = {
406                 .name = "mount",
407                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
408         },
409         [RPCAUTH_nfs] = {
410                 .name = "nfs",
411                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
412         },
413         [RPCAUTH_portmap] = {
414                 .name = "portmap",
415                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
416         },
417         [RPCAUTH_statd] = {
418                 .name = "statd",
419                 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
420         },
421 };
422
423 enum {
424         RPCAUTH_info = 2,
425         RPCAUTH_EOF
426 };
427
428 static struct rpc_filelist authfiles[] = {
429         [RPCAUTH_info] = {
430                 .name = "info",
431                 .i_fop = &rpc_info_operations,
432                 .mode = S_IFREG | S_IRUSR,
433         },
434 };
435
436 struct vfsmount *rpc_get_mount(void)
437 {
438         int err;
439
440         err = simple_pin_fs(&rpc_pipe_fs_type, &rpc_mount, &rpc_mount_count);
441         if (err != 0)
442                 return ERR_PTR(err);
443         return rpc_mount;
444 }
445
446 void rpc_put_mount(void)
447 {
448         simple_release_fs(&rpc_mount, &rpc_mount_count);
449 }
450
451 static int
452 rpc_lookup_parent(char *path, struct nameidata *nd)
453 {
454         if (path[0] == '\0')
455                 return -ENOENT;
456         nd->mnt = rpc_get_mount();
457         if (IS_ERR(nd->mnt)) {
458                 printk(KERN_WARNING "%s: %s failed to mount "
459                                "pseudofilesystem \n", __FILE__, __FUNCTION__);
460                 return PTR_ERR(nd->mnt);
461         }
462         mntget(nd->mnt);
463         nd->dentry = dget(rpc_mount->mnt_root);
464         nd->last_type = LAST_ROOT;
465         nd->flags = LOOKUP_PARENT;
466         nd->depth = 0;
467
468         if (path_walk(path, nd)) {
469                 printk(KERN_WARNING "%s: %s failed to find path %s\n",
470                                 __FILE__, __FUNCTION__, path);
471                 rpc_put_mount();
472                 return -ENOENT;
473         }
474         return 0;
475 }
476
477 static void
478 rpc_release_path(struct nameidata *nd)
479 {
480         path_release(nd);
481         rpc_put_mount();
482 }
483
484 static struct inode *
485 rpc_get_inode(struct super_block *sb, int mode)
486 {
487         struct inode *inode = new_inode(sb);
488         if (!inode)
489                 return NULL;
490         inode->i_mode = mode;
491         inode->i_uid = inode->i_gid = 0;
492         inode->i_blocks = 0;
493         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
494         switch(mode & S_IFMT) {
495                 case S_IFDIR:
496                         inode->i_fop = &simple_dir_operations;
497                         inode->i_op = &simple_dir_inode_operations;
498                         inc_nlink(inode);
499                 default:
500                         break;
501         }
502         return inode;
503 }
504
505 /*
506  * FIXME: This probably has races.
507  */
508 static void
509 rpc_depopulate(struct dentry *parent)
510 {
511         struct inode *dir = parent->d_inode;
512         struct list_head *pos, *next;
513         struct dentry *dentry, *dvec[10];
514         int n = 0;
515
516         mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD);
517 repeat:
518         spin_lock(&dcache_lock);
519         list_for_each_safe(pos, next, &parent->d_subdirs) {
520                 dentry = list_entry(pos, struct dentry, d_u.d_child);
521                 spin_lock(&dentry->d_lock);
522                 if (!d_unhashed(dentry)) {
523                         dget_locked(dentry);
524                         __d_drop(dentry);
525                         spin_unlock(&dentry->d_lock);
526                         dvec[n++] = dentry;
527                         if (n == ARRAY_SIZE(dvec))
528                                 break;
529                 } else
530                         spin_unlock(&dentry->d_lock);
531         }
532         spin_unlock(&dcache_lock);
533         if (n) {
534                 do {
535                         dentry = dvec[--n];
536                         if (dentry->d_inode) {
537                                 rpc_close_pipes(dentry->d_inode);
538                                 simple_unlink(dir, dentry);
539                         }
540                         inode_dir_notify(dir, DN_DELETE);
541                         dput(dentry);
542                 } while (n);
543                 goto repeat;
544         }
545         mutex_unlock(&dir->i_mutex);
546 }
547
548 static int
549 rpc_populate(struct dentry *parent,
550                 struct rpc_filelist *files,
551                 int start, int eof)
552 {
553         struct inode *inode, *dir = parent->d_inode;
554         void *private = RPC_I(dir)->private;
555         struct dentry *dentry;
556         int mode, i;
557
558         mutex_lock(&dir->i_mutex);
559         for (i = start; i < eof; i++) {
560                 dentry = d_alloc_name(parent, files[i].name);
561                 if (!dentry)
562                         goto out_bad;
563                 mode = files[i].mode;
564                 inode = rpc_get_inode(dir->i_sb, mode);
565                 if (!inode) {
566                         dput(dentry);
567                         goto out_bad;
568                 }
569                 inode->i_ino = i;
570                 if (files[i].i_fop)
571                         inode->i_fop = files[i].i_fop;
572                 if (private)
573                         rpc_inode_setowner(inode, private);
574                 if (S_ISDIR(mode))
575                         inc_nlink(dir);
576                 d_add(dentry, inode);
577         }
578         mutex_unlock(&dir->i_mutex);
579         return 0;
580 out_bad:
581         mutex_unlock(&dir->i_mutex);
582         printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
583                         __FILE__, __FUNCTION__, parent->d_name.name);
584         return -ENOMEM;
585 }
586
587 static int
588 __rpc_mkdir(struct inode *dir, struct dentry *dentry)
589 {
590         struct inode *inode;
591
592         inode = rpc_get_inode(dir->i_sb, S_IFDIR | S_IRUSR | S_IXUSR);
593         if (!inode)
594                 goto out_err;
595         inode->i_ino = iunique(dir->i_sb, 100);
596         d_instantiate(dentry, inode);
597         inc_nlink(dir);
598         inode_dir_notify(dir, DN_CREATE);
599         return 0;
600 out_err:
601         printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
602                         __FILE__, __FUNCTION__, dentry->d_name.name);
603         return -ENOMEM;
604 }
605
606 static int
607 __rpc_rmdir(struct inode *dir, struct dentry *dentry)
608 {
609         int error;
610
611         shrink_dcache_parent(dentry);
612         if (d_unhashed(dentry))
613                 return 0;
614         if ((error = simple_rmdir(dir, dentry)) != 0)
615                 return error;
616         if (!error) {
617                 inode_dir_notify(dir, DN_DELETE);
618                 d_drop(dentry);
619         }
620         return 0;
621 }
622
623 static struct dentry *
624 rpc_lookup_create(struct dentry *parent, const char *name, int len)
625 {
626         struct inode *dir = parent->d_inode;
627         struct dentry *dentry;
628
629         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
630         dentry = lookup_one_len(name, parent, len);
631         if (IS_ERR(dentry))
632                 goto out_err;
633         if (dentry->d_inode) {
634                 dput(dentry);
635                 dentry = ERR_PTR(-EEXIST);
636                 goto out_err;
637         }
638         return dentry;
639 out_err:
640         mutex_unlock(&dir->i_mutex);
641         return dentry;
642 }
643
644 static struct dentry *
645 rpc_lookup_negative(char *path, struct nameidata *nd)
646 {
647         struct dentry *dentry;
648         int error;
649
650         if ((error = rpc_lookup_parent(path, nd)) != 0)
651                 return ERR_PTR(error);
652         dentry = rpc_lookup_create(nd->dentry, nd->last.name, nd->last.len);
653         if (IS_ERR(dentry))
654                 rpc_release_path(nd);
655         return dentry;
656 }
657
658
659 struct dentry *
660 rpc_mkdir(char *path, struct rpc_clnt *rpc_client)
661 {
662         struct nameidata nd;
663         struct dentry *dentry;
664         struct inode *dir;
665         int error;
666
667         dentry = rpc_lookup_negative(path, &nd);
668         if (IS_ERR(dentry))
669                 return dentry;
670         dir = nd.dentry->d_inode;
671         if ((error = __rpc_mkdir(dir, dentry)) != 0)
672                 goto err_dput;
673         RPC_I(dentry->d_inode)->private = rpc_client;
674         error = rpc_populate(dentry, authfiles,
675                         RPCAUTH_info, RPCAUTH_EOF);
676         if (error)
677                 goto err_depopulate;
678         dget(dentry);
679 out:
680         mutex_unlock(&dir->i_mutex);
681         rpc_release_path(&nd);
682         return dentry;
683 err_depopulate:
684         rpc_depopulate(dentry);
685         __rpc_rmdir(dir, dentry);
686 err_dput:
687         dput(dentry);
688         printk(KERN_WARNING "%s: %s() failed to create directory %s (errno = %d)\n",
689                         __FILE__, __FUNCTION__, path, error);
690         dentry = ERR_PTR(error);
691         goto out;
692 }
693
694 int
695 rpc_rmdir(struct dentry *dentry)
696 {
697         struct dentry *parent;
698         struct inode *dir;
699         int error;
700
701         parent = dget_parent(dentry);
702         dir = parent->d_inode;
703         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
704         rpc_depopulate(dentry);
705         error = __rpc_rmdir(dir, dentry);
706         dput(dentry);
707         mutex_unlock(&dir->i_mutex);
708         dput(parent);
709         return error;
710 }
711
712 struct dentry *
713 rpc_mkpipe(struct dentry *parent, const char *name, void *private, struct rpc_pipe_ops *ops, int flags)
714 {
715         struct dentry *dentry;
716         struct inode *dir, *inode;
717         struct rpc_inode *rpci;
718
719         dentry = rpc_lookup_create(parent, name, strlen(name));
720         if (IS_ERR(dentry))
721                 return dentry;
722         dir = parent->d_inode;
723         inode = rpc_get_inode(dir->i_sb, S_IFIFO | S_IRUSR | S_IWUSR);
724         if (!inode)
725                 goto err_dput;
726         inode->i_ino = iunique(dir->i_sb, 100);
727         inode->i_fop = &rpc_pipe_fops;
728         d_instantiate(dentry, inode);
729         rpci = RPC_I(inode);
730         rpci->private = private;
731         rpci->flags = flags;
732         rpci->ops = ops;
733         inode_dir_notify(dir, DN_CREATE);
734         dget(dentry);
735 out:
736         mutex_unlock(&dir->i_mutex);
737         return dentry;
738 err_dput:
739         dput(dentry);
740         dentry = ERR_PTR(-ENOMEM);
741         printk(KERN_WARNING "%s: %s() failed to create pipe %s/%s (errno = %d)\n",
742                         __FILE__, __FUNCTION__, parent->d_name.name, name,
743                         -ENOMEM);
744         goto out;
745 }
746
747 int
748 rpc_unlink(struct dentry *dentry)
749 {
750         struct dentry *parent;
751         struct inode *dir;
752         int error = 0;
753
754         parent = dget_parent(dentry);
755         dir = parent->d_inode;
756         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
757         if (!d_unhashed(dentry)) {
758                 d_drop(dentry);
759                 if (dentry->d_inode) {
760                         rpc_close_pipes(dentry->d_inode);
761                         error = simple_unlink(dir, dentry);
762                 }
763                 inode_dir_notify(dir, DN_DELETE);
764         }
765         dput(dentry);
766         mutex_unlock(&dir->i_mutex);
767         dput(parent);
768         return error;
769 }
770
771 /*
772  * populate the filesystem
773  */
774 static struct super_operations s_ops = {
775         .alloc_inode    = rpc_alloc_inode,
776         .destroy_inode  = rpc_destroy_inode,
777         .statfs         = simple_statfs,
778 };
779
780 #define RPCAUTH_GSSMAGIC 0x67596969
781
782 static int
783 rpc_fill_super(struct super_block *sb, void *data, int silent)
784 {
785         struct inode *inode;
786         struct dentry *root;
787
788         sb->s_blocksize = PAGE_CACHE_SIZE;
789         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
790         sb->s_magic = RPCAUTH_GSSMAGIC;
791         sb->s_op = &s_ops;
792         sb->s_time_gran = 1;
793
794         inode = rpc_get_inode(sb, S_IFDIR | 0755);
795         if (!inode)
796                 return -ENOMEM;
797         root = d_alloc_root(inode);
798         if (!root) {
799                 iput(inode);
800                 return -ENOMEM;
801         }
802         if (rpc_populate(root, files, RPCAUTH_Root + 1, RPCAUTH_RootEOF))
803                 goto out;
804         sb->s_root = root;
805         return 0;
806 out:
807         d_genocide(root);
808         dput(root);
809         return -ENOMEM;
810 }
811
812 static int
813 rpc_get_sb(struct file_system_type *fs_type,
814                 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
815 {
816         return get_sb_single(fs_type, flags, data, rpc_fill_super, mnt);
817 }
818
819 static struct file_system_type rpc_pipe_fs_type = {
820         .owner          = THIS_MODULE,
821         .name           = "rpc_pipefs",
822         .get_sb         = rpc_get_sb,
823         .kill_sb        = kill_litter_super,
824 };
825
826 static void
827 init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
828 {
829         struct rpc_inode *rpci = (struct rpc_inode *) foo;
830
831         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
832             SLAB_CTOR_CONSTRUCTOR) {
833                 inode_init_once(&rpci->vfs_inode);
834                 rpci->private = NULL;
835                 rpci->nreaders = 0;
836                 rpci->nwriters = 0;
837                 INIT_LIST_HEAD(&rpci->in_upcall);
838                 INIT_LIST_HEAD(&rpci->pipe);
839                 rpci->pipelen = 0;
840                 init_waitqueue_head(&rpci->waitq);
841                 INIT_DELAYED_WORK(&rpci->queue_timeout,
842                                     rpc_timeout_upcall_queue);
843                 rpci->ops = NULL;
844         }
845 }
846
847 int register_rpc_pipefs(void)
848 {
849         rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
850                                 sizeof(struct rpc_inode),
851                                 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
852                                                 SLAB_MEM_SPREAD),
853                                 init_once, NULL);
854         if (!rpc_inode_cachep)
855                 return -ENOMEM;
856         register_filesystem(&rpc_pipe_fs_type);
857         return 0;
858 }
859
860 void unregister_rpc_pipefs(void)
861 {
862         kmem_cache_destroy(rpc_inode_cachep);
863         unregister_filesystem(&rpc_pipe_fs_type);
864 }