Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/shaggy...
[linux-2.6] / 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: %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         const 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 struct vfsmount *rpc_get_mount(void)
438 {
439         int err;
440
441         err = simple_pin_fs(&rpc_pipe_fs_type, &rpc_mount, &rpc_mount_count);
442         if (err != 0)
443                 return ERR_PTR(err);
444         return rpc_mount;
445 }
446
447 void rpc_put_mount(void)
448 {
449         simple_release_fs(&rpc_mount, &rpc_mount_count);
450 }
451
452 static int
453 rpc_lookup_parent(char *path, struct nameidata *nd)
454 {
455         if (path[0] == '\0')
456                 return -ENOENT;
457         nd->mnt = rpc_get_mount();
458         if (IS_ERR(nd->mnt)) {
459                 printk(KERN_WARNING "%s: %s failed to mount "
460                                "pseudofilesystem \n", __FILE__, __FUNCTION__);
461                 return PTR_ERR(nd->mnt);
462         }
463         mntget(nd->mnt);
464         nd->dentry = dget(rpc_mount->mnt_root);
465         nd->last_type = LAST_ROOT;
466         nd->flags = LOOKUP_PARENT;
467         nd->depth = 0;
468
469         if (path_walk(path, nd)) {
470                 printk(KERN_WARNING "%s: %s failed to find path %s\n",
471                                 __FILE__, __FUNCTION__, path);
472                 rpc_put_mount();
473                 return -ENOENT;
474         }
475         return 0;
476 }
477
478 static void
479 rpc_release_path(struct nameidata *nd)
480 {
481         path_release(nd);
482         rpc_put_mount();
483 }
484
485 static struct inode *
486 rpc_get_inode(struct super_block *sb, int mode)
487 {
488         struct inode *inode = new_inode(sb);
489         if (!inode)
490                 return NULL;
491         inode->i_mode = mode;
492         inode->i_uid = inode->i_gid = 0;
493         inode->i_blksize = PAGE_CACHE_SIZE;
494         inode->i_blocks = 0;
495         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
496         switch(mode & S_IFMT) {
497                 case S_IFDIR:
498                         inode->i_fop = &simple_dir_operations;
499                         inode->i_op = &simple_dir_inode_operations;
500                         inode->i_nlink++;
501                 default:
502                         break;
503         }
504         return inode;
505 }
506
507 /*
508  * FIXME: This probably has races.
509  */
510 static void
511 rpc_depopulate(struct dentry *parent)
512 {
513         struct inode *dir = parent->d_inode;
514         struct list_head *pos, *next;
515         struct dentry *dentry, *dvec[10];
516         int n = 0;
517
518         mutex_lock_nested(&dir->i_mutex, I_MUTEX_CHILD);
519 repeat:
520         spin_lock(&dcache_lock);
521         list_for_each_safe(pos, next, &parent->d_subdirs) {
522                 dentry = list_entry(pos, struct dentry, d_u.d_child);
523                 spin_lock(&dentry->d_lock);
524                 if (!d_unhashed(dentry)) {
525                         dget_locked(dentry);
526                         __d_drop(dentry);
527                         spin_unlock(&dentry->d_lock);
528                         dvec[n++] = dentry;
529                         if (n == ARRAY_SIZE(dvec))
530                                 break;
531                 } else
532                         spin_unlock(&dentry->d_lock);
533         }
534         spin_unlock(&dcache_lock);
535         if (n) {
536                 do {
537                         dentry = dvec[--n];
538                         if (dentry->d_inode) {
539                                 rpc_close_pipes(dentry->d_inode);
540                                 simple_unlink(dir, dentry);
541                         }
542                         dput(dentry);
543                 } while (n);
544                 goto repeat;
545         }
546         mutex_unlock(&dir->i_mutex);
547 }
548
549 static int
550 rpc_populate(struct dentry *parent,
551                 struct rpc_filelist *files,
552                 int start, int eof)
553 {
554         struct inode *inode, *dir = parent->d_inode;
555         void *private = RPC_I(dir)->private;
556         struct dentry *dentry;
557         int mode, i;
558
559         mutex_lock(&dir->i_mutex);
560         for (i = start; i < eof; i++) {
561                 dentry = d_alloc_name(parent, files[i].name);
562                 if (!dentry)
563                         goto out_bad;
564                 mode = files[i].mode;
565                 inode = rpc_get_inode(dir->i_sb, mode);
566                 if (!inode) {
567                         dput(dentry);
568                         goto out_bad;
569                 }
570                 inode->i_ino = i;
571                 if (files[i].i_fop)
572                         inode->i_fop = files[i].i_fop;
573                 if (private)
574                         rpc_inode_setowner(inode, private);
575                 if (S_ISDIR(mode))
576                         dir->i_nlink++;
577                 d_add(dentry, inode);
578         }
579         mutex_unlock(&dir->i_mutex);
580         return 0;
581 out_bad:
582         mutex_unlock(&dir->i_mutex);
583         printk(KERN_WARNING "%s: %s failed to populate directory %s\n",
584                         __FILE__, __FUNCTION__, parent->d_name.name);
585         return -ENOMEM;
586 }
587
588 static int
589 __rpc_mkdir(struct inode *dir, struct dentry *dentry)
590 {
591         struct inode *inode;
592
593         inode = rpc_get_inode(dir->i_sb, S_IFDIR | S_IRUSR | S_IXUSR);
594         if (!inode)
595                 goto out_err;
596         inode->i_ino = iunique(dir->i_sb, 100);
597         d_instantiate(dentry, inode);
598         dir->i_nlink++;
599         inode_dir_notify(dir, DN_CREATE);
600         return 0;
601 out_err:
602         printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
603                         __FILE__, __FUNCTION__, dentry->d_name.name);
604         return -ENOMEM;
605 }
606
607 static int
608 __rpc_rmdir(struct inode *dir, struct dentry *dentry)
609 {
610         int error;
611
612         shrink_dcache_parent(dentry);
613         if (dentry->d_inode)
614                 rpc_close_pipes(dentry->d_inode);
615         if ((error = simple_rmdir(dir, dentry)) != 0)
616                 return error;
617         if (!error) {
618                 inode_dir_notify(dir, DN_DELETE);
619                 d_drop(dentry);
620         }
621         return 0;
622 }
623
624 static struct dentry *
625 rpc_lookup_negative(char *path, struct nameidata *nd)
626 {
627         struct dentry *dentry;
628         struct inode *dir;
629         int error;
630
631         if ((error = rpc_lookup_parent(path, nd)) != 0)
632                 return ERR_PTR(error);
633         dir = nd->dentry->d_inode;
634         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
635         dentry = lookup_one_len(nd->last.name, nd->dentry, nd->last.len);
636         if (IS_ERR(dentry))
637                 goto out_err;
638         if (dentry->d_inode) {
639                 dput(dentry);
640                 dentry = ERR_PTR(-EEXIST);
641                 goto out_err;
642         }
643         return dentry;
644 out_err:
645         mutex_unlock(&dir->i_mutex);
646         rpc_release_path(nd);
647         return dentry;
648 }
649
650
651 struct dentry *
652 rpc_mkdir(char *path, struct rpc_clnt *rpc_client)
653 {
654         struct nameidata nd;
655         struct dentry *dentry;
656         struct inode *dir;
657         int error;
658
659         dentry = rpc_lookup_negative(path, &nd);
660         if (IS_ERR(dentry))
661                 return dentry;
662         dir = nd.dentry->d_inode;
663         if ((error = __rpc_mkdir(dir, dentry)) != 0)
664                 goto err_dput;
665         RPC_I(dentry->d_inode)->private = rpc_client;
666         error = rpc_populate(dentry, authfiles,
667                         RPCAUTH_info, RPCAUTH_EOF);
668         if (error)
669                 goto err_depopulate;
670 out:
671         mutex_unlock(&dir->i_mutex);
672         rpc_release_path(&nd);
673         return dget(dentry);
674 err_depopulate:
675         rpc_depopulate(dentry);
676         __rpc_rmdir(dir, dentry);
677 err_dput:
678         dput(dentry);
679         printk(KERN_WARNING "%s: %s() failed to create directory %s (errno = %d)\n",
680                         __FILE__, __FUNCTION__, path, error);
681         dentry = ERR_PTR(error);
682         goto out;
683 }
684
685 int
686 rpc_rmdir(char *path)
687 {
688         struct nameidata nd;
689         struct dentry *dentry;
690         struct inode *dir;
691         int error;
692
693         if ((error = rpc_lookup_parent(path, &nd)) != 0)
694                 return error;
695         dir = nd.dentry->d_inode;
696         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
697         dentry = lookup_one_len(nd.last.name, nd.dentry, nd.last.len);
698         if (IS_ERR(dentry)) {
699                 error = PTR_ERR(dentry);
700                 goto out_release;
701         }
702         rpc_depopulate(dentry);
703         error = __rpc_rmdir(dir, dentry);
704         dput(dentry);
705 out_release:
706         mutex_unlock(&dir->i_mutex);
707         rpc_release_path(&nd);
708         return error;
709 }
710
711 struct dentry *
712 rpc_mkpipe(char *path, void *private, struct rpc_pipe_ops *ops, int flags)
713 {
714         struct nameidata nd;
715         struct dentry *dentry;
716         struct inode *dir, *inode;
717         struct rpc_inode *rpci;
718
719         dentry = rpc_lookup_negative(path, &nd);
720         if (IS_ERR(dentry))
721                 return dentry;
722         dir = nd.dentry->d_inode;
723         inode = rpc_get_inode(dir->i_sb, S_IFSOCK | 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 out:
735         mutex_unlock(&dir->i_mutex);
736         rpc_release_path(&nd);
737         return dget(dentry);
738 err_dput:
739         dput(dentry);
740         dentry = ERR_PTR(-ENOMEM);
741         printk(KERN_WARNING "%s: %s() failed to create pipe %s (errno = %d)\n",
742                         __FILE__, __FUNCTION__, path, -ENOMEM);
743         goto out;
744 }
745
746 int
747 rpc_unlink(char *path)
748 {
749         struct nameidata nd;
750         struct dentry *dentry;
751         struct inode *dir;
752         int error;
753
754         if ((error = rpc_lookup_parent(path, &nd)) != 0)
755                 return error;
756         dir = nd.dentry->d_inode;
757         mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
758         dentry = lookup_one_len(nd.last.name, nd.dentry, nd.last.len);
759         if (IS_ERR(dentry)) {
760                 error = PTR_ERR(dentry);
761                 goto out_release;
762         }
763         d_drop(dentry);
764         if (dentry->d_inode) {
765                 rpc_close_pipes(dentry->d_inode);
766                 error = simple_unlink(dir, dentry);
767         }
768         dput(dentry);
769         inode_dir_notify(dir, DN_DELETE);
770 out_release:
771         mutex_unlock(&dir->i_mutex);
772         rpc_release_path(&nd);
773         return error;
774 }
775
776 /*
777  * populate the filesystem
778  */
779 static struct super_operations s_ops = {
780         .alloc_inode    = rpc_alloc_inode,
781         .destroy_inode  = rpc_destroy_inode,
782         .statfs         = simple_statfs,
783 };
784
785 #define RPCAUTH_GSSMAGIC 0x67596969
786
787 static int
788 rpc_fill_super(struct super_block *sb, void *data, int silent)
789 {
790         struct inode *inode;
791         struct dentry *root;
792
793         sb->s_blocksize = PAGE_CACHE_SIZE;
794         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
795         sb->s_magic = RPCAUTH_GSSMAGIC;
796         sb->s_op = &s_ops;
797         sb->s_time_gran = 1;
798
799         inode = rpc_get_inode(sb, S_IFDIR | 0755);
800         if (!inode)
801                 return -ENOMEM;
802         root = d_alloc_root(inode);
803         if (!root) {
804                 iput(inode);
805                 return -ENOMEM;
806         }
807         if (rpc_populate(root, files, RPCAUTH_Root + 1, RPCAUTH_RootEOF))
808                 goto out;
809         sb->s_root = root;
810         return 0;
811 out:
812         d_genocide(root);
813         dput(root);
814         return -ENOMEM;
815 }
816
817 static int
818 rpc_get_sb(struct file_system_type *fs_type,
819                 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
820 {
821         return get_sb_single(fs_type, flags, data, rpc_fill_super, mnt);
822 }
823
824 static struct file_system_type rpc_pipe_fs_type = {
825         .owner          = THIS_MODULE,
826         .name           = "rpc_pipefs",
827         .get_sb         = rpc_get_sb,
828         .kill_sb        = kill_litter_super,
829 };
830
831 static void
832 init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
833 {
834         struct rpc_inode *rpci = (struct rpc_inode *) foo;
835
836         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
837             SLAB_CTOR_CONSTRUCTOR) {
838                 inode_init_once(&rpci->vfs_inode);
839                 rpci->private = NULL;
840                 rpci->nreaders = 0;
841                 rpci->nwriters = 0;
842                 INIT_LIST_HEAD(&rpci->in_upcall);
843                 INIT_LIST_HEAD(&rpci->pipe);
844                 rpci->pipelen = 0;
845                 init_waitqueue_head(&rpci->waitq);
846                 INIT_WORK(&rpci->queue_timeout, rpc_timeout_upcall_queue, rpci);
847                 rpci->ops = NULL;
848         }
849 }
850
851 int register_rpc_pipefs(void)
852 {
853         rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
854                                 sizeof(struct rpc_inode),
855                                 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
856                                                 SLAB_MEM_SPREAD),
857                                 init_once, NULL);
858         if (!rpc_inode_cachep)
859                 return -ENOMEM;
860         register_filesystem(&rpc_pipe_fs_type);
861         return 0;
862 }
863
864 void unregister_rpc_pipefs(void)
865 {
866         if (kmem_cache_destroy(rpc_inode_cachep))
867                 printk(KERN_WARNING "RPC: unable to free inode cache\n");
868         unregister_filesystem(&rpc_pipe_fs_type);
869 }