1 // SPDX-License-Identifier: GPL-2.0-only
3 * net/sunrpc/rpc_pipe.c
5 * Userland/kernel interface for rpcauth_gss.
6 * Code shamelessly plagiarized from fs/nfsd/nfsctl.c
9 * Copyright (c) 2002, Trond Myklebust <trond.myklebust@fys.uio.no>
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/fs_context.h>
18 #include <linux/namei.h>
19 #include <linux/fsnotify.h>
20 #include <linux/kernel.h>
21 #include <linux/rcupdate.h>
22 #include <linux/utsname.h>
24 #include <asm/ioctls.h>
25 #include <linux/poll.h>
26 #include <linux/wait.h>
27 #include <linux/seq_file.h>
29 #include <linux/sunrpc/clnt.h>
30 #include <linux/workqueue.h>
31 #include <linux/sunrpc/rpc_pipe_fs.h>
32 #include <linux/sunrpc/cache.h>
33 #include <linux/nsproxy.h>
34 #include <linux/notifier.h>
39 #define RPCDBG_FACILITY RPCDBG_DEBUG
41 #define NET_NAME(net) ((net == &init_net) ? " (init_net)" : "")
43 static struct file_system_type rpc_pipe_fs_type;
44 static const struct rpc_pipe_ops gssd_dummy_pipe_ops;
46 static struct kmem_cache *rpc_inode_cachep __read_mostly;
48 #define RPC_UPCALL_TIMEOUT (30*HZ)
50 static BLOCKING_NOTIFIER_HEAD(rpc_pipefs_notifier_list);
52 int rpc_pipefs_notifier_register(struct notifier_block *nb)
54 return blocking_notifier_chain_register(&rpc_pipefs_notifier_list, nb);
56 EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_register);
58 void rpc_pipefs_notifier_unregister(struct notifier_block *nb)
60 blocking_notifier_chain_unregister(&rpc_pipefs_notifier_list, nb);
62 EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_unregister);
64 static void rpc_purge_list(wait_queue_head_t *waitq, struct list_head *head,
65 void (*destroy_msg)(struct rpc_pipe_msg *), int err)
67 struct rpc_pipe_msg *msg;
72 msg = list_entry(head->next, struct rpc_pipe_msg, list);
73 list_del_init(&msg->list);
76 } while (!list_empty(head));
83 rpc_timeout_upcall_queue(struct work_struct *work)
86 struct rpc_pipe *pipe =
87 container_of(work, struct rpc_pipe, queue_timeout.work);
88 void (*destroy_msg)(struct rpc_pipe_msg *);
89 struct dentry *dentry;
91 spin_lock(&pipe->lock);
92 destroy_msg = pipe->ops->destroy_msg;
93 if (pipe->nreaders == 0) {
94 list_splice_init(&pipe->pipe, &free_list);
97 dentry = dget(pipe->dentry);
98 spin_unlock(&pipe->lock);
99 rpc_purge_list(dentry ? &RPC_I(d_inode(dentry))->waitq : NULL,
100 &free_list, destroy_msg, -ETIMEDOUT);
104 ssize_t rpc_pipe_generic_upcall(struct file *filp, struct rpc_pipe_msg *msg,
105 char __user *dst, size_t buflen)
107 char *data = (char *)msg->data + msg->copied;
108 size_t mlen = min(msg->len - msg->copied, buflen);
111 left = copy_to_user(dst, data, mlen);
113 msg->errno = -EFAULT;
122 EXPORT_SYMBOL_GPL(rpc_pipe_generic_upcall);
125 * rpc_queue_upcall - queue an upcall message to userspace
126 * @pipe: upcall pipe on which to queue given message
127 * @msg: message to queue
129 * Call with an @inode created by rpc_mkpipe() to queue an upcall.
130 * A userspace process may then later read the upcall by performing a
131 * read on an open file for this inode. It is up to the caller to
132 * initialize the fields of @msg (other than @msg->list) appropriately.
135 rpc_queue_upcall(struct rpc_pipe *pipe, struct rpc_pipe_msg *msg)
138 struct dentry *dentry;
140 spin_lock(&pipe->lock);
141 if (pipe->nreaders) {
142 list_add_tail(&msg->list, &pipe->pipe);
143 pipe->pipelen += msg->len;
145 } else if (pipe->flags & RPC_PIPE_WAIT_FOR_OPEN) {
146 if (list_empty(&pipe->pipe))
147 queue_delayed_work(rpciod_workqueue,
148 &pipe->queue_timeout,
150 list_add_tail(&msg->list, &pipe->pipe);
151 pipe->pipelen += msg->len;
154 dentry = dget(pipe->dentry);
155 spin_unlock(&pipe->lock);
157 wake_up(&RPC_I(d_inode(dentry))->waitq);
162 EXPORT_SYMBOL_GPL(rpc_queue_upcall);
165 rpc_inode_setowner(struct inode *inode, void *private)
167 RPC_I(inode)->private = private;
171 rpc_close_pipes(struct inode *inode)
173 struct rpc_pipe *pipe = RPC_I(inode)->pipe;
175 LIST_HEAD(free_list);
178 spin_lock(&pipe->lock);
179 need_release = pipe->nreaders != 0 || pipe->nwriters != 0;
181 list_splice_init(&pipe->in_upcall, &free_list);
182 list_splice_init(&pipe->pipe, &free_list);
185 spin_unlock(&pipe->lock);
186 rpc_purge_list(&RPC_I(inode)->waitq, &free_list, pipe->ops->destroy_msg, -EPIPE);
188 if (need_release && pipe->ops->release_pipe)
189 pipe->ops->release_pipe(inode);
190 cancel_delayed_work_sync(&pipe->queue_timeout);
191 rpc_inode_setowner(inode, NULL);
192 RPC_I(inode)->pipe = NULL;
196 static struct inode *
197 rpc_alloc_inode(struct super_block *sb)
199 struct rpc_inode *rpci;
200 rpci = kmem_cache_alloc(rpc_inode_cachep, GFP_KERNEL);
203 return &rpci->vfs_inode;
207 rpc_free_inode(struct inode *inode)
209 kmem_cache_free(rpc_inode_cachep, RPC_I(inode));
213 rpc_pipe_open(struct inode *inode, struct file *filp)
215 struct rpc_pipe *pipe;
220 pipe = RPC_I(inode)->pipe;
223 first_open = pipe->nreaders == 0 && pipe->nwriters == 0;
224 if (first_open && pipe->ops->open_pipe) {
225 res = pipe->ops->open_pipe(inode);
229 if (filp->f_mode & FMODE_READ)
231 if (filp->f_mode & FMODE_WRITE)
240 rpc_pipe_release(struct inode *inode, struct file *filp)
242 struct rpc_pipe *pipe;
243 struct rpc_pipe_msg *msg;
247 pipe = RPC_I(inode)->pipe;
250 msg = filp->private_data;
252 spin_lock(&pipe->lock);
253 msg->errno = -EAGAIN;
254 list_del_init(&msg->list);
255 spin_unlock(&pipe->lock);
256 pipe->ops->destroy_msg(msg);
258 if (filp->f_mode & FMODE_WRITE)
260 if (filp->f_mode & FMODE_READ) {
262 if (pipe->nreaders == 0) {
263 LIST_HEAD(free_list);
264 spin_lock(&pipe->lock);
265 list_splice_init(&pipe->pipe, &free_list);
267 spin_unlock(&pipe->lock);
268 rpc_purge_list(&RPC_I(inode)->waitq, &free_list,
269 pipe->ops->destroy_msg, -EAGAIN);
272 last_close = pipe->nwriters == 0 && pipe->nreaders == 0;
273 if (last_close && pipe->ops->release_pipe)
274 pipe->ops->release_pipe(inode);
281 rpc_pipe_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
283 struct inode *inode = file_inode(filp);
284 struct rpc_pipe *pipe;
285 struct rpc_pipe_msg *msg;
289 pipe = RPC_I(inode)->pipe;
294 msg = filp->private_data;
296 spin_lock(&pipe->lock);
297 if (!list_empty(&pipe->pipe)) {
298 msg = list_entry(pipe->pipe.next,
301 list_move(&msg->list, &pipe->in_upcall);
302 pipe->pipelen -= msg->len;
303 filp->private_data = msg;
306 spin_unlock(&pipe->lock);
310 /* NOTE: it is up to the callback to update msg->copied */
311 res = pipe->ops->upcall(filp, msg, buf, len);
312 if (res < 0 || msg->len == msg->copied) {
313 filp->private_data = NULL;
314 spin_lock(&pipe->lock);
315 list_del_init(&msg->list);
316 spin_unlock(&pipe->lock);
317 pipe->ops->destroy_msg(msg);
325 rpc_pipe_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
327 struct inode *inode = file_inode(filp);
332 if (RPC_I(inode)->pipe != NULL)
333 res = RPC_I(inode)->pipe->ops->downcall(filp, buf, len);
339 rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
341 struct inode *inode = file_inode(filp);
342 struct rpc_inode *rpci = RPC_I(inode);
343 __poll_t mask = EPOLLOUT | EPOLLWRNORM;
345 poll_wait(filp, &rpci->waitq, wait);
348 if (rpci->pipe == NULL)
349 mask |= EPOLLERR | EPOLLHUP;
350 else if (filp->private_data || !list_empty(&rpci->pipe->pipe))
351 mask |= EPOLLIN | EPOLLRDNORM;
357 rpc_pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
359 struct inode *inode = file_inode(filp);
360 struct rpc_pipe *pipe;
366 pipe = RPC_I(inode)->pipe;
371 spin_lock(&pipe->lock);
373 if (filp->private_data) {
374 struct rpc_pipe_msg *msg;
375 msg = filp->private_data;
376 len += msg->len - msg->copied;
378 spin_unlock(&pipe->lock);
380 return put_user(len, (int __user *)arg);
386 static const struct file_operations rpc_pipe_fops = {
387 .owner = THIS_MODULE,
389 .read = rpc_pipe_read,
390 .write = rpc_pipe_write,
391 .poll = rpc_pipe_poll,
392 .unlocked_ioctl = rpc_pipe_ioctl,
393 .open = rpc_pipe_open,
394 .release = rpc_pipe_release,
398 rpc_show_info(struct seq_file *m, void *v)
400 struct rpc_clnt *clnt = m->private;
403 seq_printf(m, "RPC server: %s\n",
404 rcu_dereference(clnt->cl_xprt)->servername);
405 seq_printf(m, "service: %s (%d) version %d\n", clnt->cl_program->name,
406 clnt->cl_prog, clnt->cl_vers);
407 seq_printf(m, "address: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
408 seq_printf(m, "protocol: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PROTO));
409 seq_printf(m, "port: %s\n", rpc_peeraddr2str(clnt, RPC_DISPLAY_PORT));
415 rpc_info_open(struct inode *inode, struct file *file)
417 struct rpc_clnt *clnt = NULL;
418 int ret = single_open(file, rpc_show_info, NULL);
421 struct seq_file *m = file->private_data;
423 spin_lock(&file->f_path.dentry->d_lock);
424 if (!d_unhashed(file->f_path.dentry))
425 clnt = RPC_I(inode)->private;
426 if (clnt != NULL && atomic_inc_not_zero(&clnt->cl_count)) {
427 spin_unlock(&file->f_path.dentry->d_lock);
430 spin_unlock(&file->f_path.dentry->d_lock);
431 single_release(inode, file);
439 rpc_info_release(struct inode *inode, struct file *file)
441 struct seq_file *m = file->private_data;
442 struct rpc_clnt *clnt = (struct rpc_clnt *)m->private;
445 rpc_release_client(clnt);
446 return single_release(inode, file);
449 static const struct file_operations rpc_info_operations = {
450 .owner = THIS_MODULE,
451 .open = rpc_info_open,
454 .release = rpc_info_release,
459 * Description of fs contents.
461 struct rpc_filelist {
463 const struct file_operations *i_fop;
467 static struct inode *
468 rpc_get_inode(struct super_block *sb, umode_t mode)
470 struct inode *inode = new_inode(sb);
473 inode->i_ino = get_next_ino();
474 inode->i_mode = mode;
475 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
476 switch (mode & S_IFMT) {
478 inode->i_fop = &simple_dir_operations;
479 inode->i_op = &simple_dir_inode_operations;
487 static int __rpc_create_common(struct inode *dir, struct dentry *dentry,
489 const struct file_operations *i_fop,
495 inode = rpc_get_inode(dir->i_sb, mode);
498 inode->i_ino = iunique(dir->i_sb, 100);
500 inode->i_fop = i_fop;
502 rpc_inode_setowner(inode, private);
503 d_add(dentry, inode);
506 printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %pd\n",
507 __FILE__, __func__, dentry);
512 static int __rpc_create(struct inode *dir, struct dentry *dentry,
514 const struct file_operations *i_fop,
519 err = __rpc_create_common(dir, dentry, S_IFREG | mode, i_fop, private);
522 fsnotify_create(dir, dentry);
526 static int __rpc_mkdir(struct inode *dir, struct dentry *dentry,
528 const struct file_operations *i_fop,
533 err = __rpc_create_common(dir, dentry, S_IFDIR | mode, i_fop, private);
537 fsnotify_mkdir(dir, dentry);
542 init_pipe(struct rpc_pipe *pipe)
546 INIT_LIST_HEAD(&pipe->in_upcall);
547 INIT_LIST_HEAD(&pipe->in_downcall);
548 INIT_LIST_HEAD(&pipe->pipe);
550 INIT_DELAYED_WORK(&pipe->queue_timeout,
551 rpc_timeout_upcall_queue);
553 spin_lock_init(&pipe->lock);
557 void rpc_destroy_pipe_data(struct rpc_pipe *pipe)
561 EXPORT_SYMBOL_GPL(rpc_destroy_pipe_data);
563 struct rpc_pipe *rpc_mkpipe_data(const struct rpc_pipe_ops *ops, int flags)
565 struct rpc_pipe *pipe;
567 pipe = kzalloc(sizeof(struct rpc_pipe), GFP_KERNEL);
569 return ERR_PTR(-ENOMEM);
575 EXPORT_SYMBOL_GPL(rpc_mkpipe_data);
577 static int __rpc_mkpipe_dentry(struct inode *dir, struct dentry *dentry,
579 const struct file_operations *i_fop,
581 struct rpc_pipe *pipe)
583 struct rpc_inode *rpci;
586 err = __rpc_create_common(dir, dentry, S_IFIFO | mode, i_fop, private);
589 rpci = RPC_I(d_inode(dentry));
590 rpci->private = private;
592 fsnotify_create(dir, dentry);
596 static int __rpc_rmdir(struct inode *dir, struct dentry *dentry)
601 ret = simple_rmdir(dir, dentry);
603 fsnotify_rmdir(dir, dentry);
609 static int __rpc_unlink(struct inode *dir, struct dentry *dentry)
614 ret = simple_unlink(dir, dentry);
616 fsnotify_unlink(dir, dentry);
622 static int __rpc_rmpipe(struct inode *dir, struct dentry *dentry)
624 struct inode *inode = d_inode(dentry);
626 rpc_close_pipes(inode);
627 return __rpc_unlink(dir, dentry);
630 static struct dentry *__rpc_lookup_create_exclusive(struct dentry *parent,
633 struct qstr q = QSTR_INIT(name, strlen(name));
634 struct dentry *dentry = d_hash_and_lookup(parent, &q);
636 dentry = d_alloc(parent, &q);
638 return ERR_PTR(-ENOMEM);
640 if (d_really_is_negative(dentry))
643 return ERR_PTR(-EEXIST);
647 * FIXME: This probably has races.
649 static void __rpc_depopulate(struct dentry *parent,
650 const struct rpc_filelist *files,
653 struct inode *dir = d_inode(parent);
654 struct dentry *dentry;
658 for (i = start; i < eof; i++) {
659 name.name = files[i].name;
660 name.len = strlen(files[i].name);
661 dentry = d_hash_and_lookup(parent, &name);
665 if (d_really_is_negative(dentry))
667 switch (d_inode(dentry)->i_mode & S_IFMT) {
671 __rpc_unlink(dir, dentry);
674 __rpc_rmdir(dir, dentry);
681 static void rpc_depopulate(struct dentry *parent,
682 const struct rpc_filelist *files,
685 struct inode *dir = d_inode(parent);
687 inode_lock_nested(dir, I_MUTEX_CHILD);
688 __rpc_depopulate(parent, files, start, eof);
692 static int rpc_populate(struct dentry *parent,
693 const struct rpc_filelist *files,
697 struct inode *dir = d_inode(parent);
698 struct dentry *dentry;
702 for (i = start; i < eof; i++) {
703 dentry = __rpc_lookup_create_exclusive(parent, files[i].name);
704 err = PTR_ERR(dentry);
707 switch (files[i].mode & S_IFMT) {
711 err = __rpc_create(dir, dentry,
717 err = __rpc_mkdir(dir, dentry,
728 __rpc_depopulate(parent, files, start, eof);
730 printk(KERN_WARNING "%s: %s failed to populate directory %pd\n",
731 __FILE__, __func__, parent);
735 static struct dentry *rpc_mkdir_populate(struct dentry *parent,
736 const char *name, umode_t mode, void *private,
737 int (*populate)(struct dentry *, void *), void *args_populate)
739 struct dentry *dentry;
740 struct inode *dir = d_inode(parent);
743 inode_lock_nested(dir, I_MUTEX_PARENT);
744 dentry = __rpc_lookup_create_exclusive(parent, name);
747 error = __rpc_mkdir(dir, dentry, mode, NULL, private);
750 if (populate != NULL) {
751 error = populate(dentry, args_populate);
759 __rpc_rmdir(dir, dentry);
761 dentry = ERR_PTR(error);
765 static int rpc_rmdir_depopulate(struct dentry *dentry,
766 void (*depopulate)(struct dentry *))
768 struct dentry *parent;
772 parent = dget_parent(dentry);
773 dir = d_inode(parent);
774 inode_lock_nested(dir, I_MUTEX_PARENT);
775 if (depopulate != NULL)
777 error = __rpc_rmdir(dir, dentry);
784 * rpc_mkpipe - make an rpc_pipefs file for kernel<->userspace communication
785 * @parent: dentry of directory to create new "pipe" in
786 * @name: name of pipe
787 * @private: private data to associate with the pipe, for the caller's use
788 * @pipe: &rpc_pipe containing input parameters
790 * Data is made available for userspace to read by calls to
791 * rpc_queue_upcall(). The actual reads will result in calls to
792 * @ops->upcall, which will be called with the file pointer,
793 * message, and userspace buffer to copy to.
795 * Writes can come at any time, and do not necessarily have to be
796 * responses to upcalls. They will result in calls to @msg->downcall.
798 * The @private argument passed here will be available to all these methods
799 * from the file pointer, via RPC_I(file_inode(file))->private.
801 struct dentry *rpc_mkpipe_dentry(struct dentry *parent, const char *name,
802 void *private, struct rpc_pipe *pipe)
804 struct dentry *dentry;
805 struct inode *dir = d_inode(parent);
806 umode_t umode = S_IFIFO | 0600;
809 if (pipe->ops->upcall == NULL)
811 if (pipe->ops->downcall == NULL)
814 inode_lock_nested(dir, I_MUTEX_PARENT);
815 dentry = __rpc_lookup_create_exclusive(parent, name);
818 err = __rpc_mkpipe_dentry(dir, dentry, umode, &rpc_pipe_fops,
826 dentry = ERR_PTR(err);
827 printk(KERN_WARNING "%s: %s() failed to create pipe %pd/%s (errno = %d)\n",
828 __FILE__, __func__, parent, name,
832 EXPORT_SYMBOL_GPL(rpc_mkpipe_dentry);
835 * rpc_unlink - remove a pipe
836 * @dentry: dentry for the pipe, as returned from rpc_mkpipe
838 * After this call, lookups will no longer find the pipe, and any
839 * attempts to read or write using preexisting opens of the pipe will
843 rpc_unlink(struct dentry *dentry)
845 struct dentry *parent;
849 parent = dget_parent(dentry);
850 dir = d_inode(parent);
851 inode_lock_nested(dir, I_MUTEX_PARENT);
852 error = __rpc_rmpipe(dir, dentry);
857 EXPORT_SYMBOL_GPL(rpc_unlink);
860 * rpc_init_pipe_dir_head - initialise a struct rpc_pipe_dir_head
861 * @pdh: pointer to struct rpc_pipe_dir_head
863 void rpc_init_pipe_dir_head(struct rpc_pipe_dir_head *pdh)
865 INIT_LIST_HEAD(&pdh->pdh_entries);
866 pdh->pdh_dentry = NULL;
868 EXPORT_SYMBOL_GPL(rpc_init_pipe_dir_head);
871 * rpc_init_pipe_dir_object - initialise a struct rpc_pipe_dir_object
872 * @pdo: pointer to struct rpc_pipe_dir_object
873 * @pdo_ops: pointer to const struct rpc_pipe_dir_object_ops
874 * @pdo_data: pointer to caller-defined data
876 void rpc_init_pipe_dir_object(struct rpc_pipe_dir_object *pdo,
877 const struct rpc_pipe_dir_object_ops *pdo_ops,
880 INIT_LIST_HEAD(&pdo->pdo_head);
881 pdo->pdo_ops = pdo_ops;
882 pdo->pdo_data = pdo_data;
884 EXPORT_SYMBOL_GPL(rpc_init_pipe_dir_object);
887 rpc_add_pipe_dir_object_locked(struct net *net,
888 struct rpc_pipe_dir_head *pdh,
889 struct rpc_pipe_dir_object *pdo)
894 ret = pdo->pdo_ops->create(pdh->pdh_dentry, pdo);
896 list_add_tail(&pdo->pdo_head, &pdh->pdh_entries);
901 rpc_remove_pipe_dir_object_locked(struct net *net,
902 struct rpc_pipe_dir_head *pdh,
903 struct rpc_pipe_dir_object *pdo)
906 pdo->pdo_ops->destroy(pdh->pdh_dentry, pdo);
907 list_del_init(&pdo->pdo_head);
911 * rpc_add_pipe_dir_object - associate a rpc_pipe_dir_object to a directory
912 * @net: pointer to struct net
913 * @pdh: pointer to struct rpc_pipe_dir_head
914 * @pdo: pointer to struct rpc_pipe_dir_object
918 rpc_add_pipe_dir_object(struct net *net,
919 struct rpc_pipe_dir_head *pdh,
920 struct rpc_pipe_dir_object *pdo)
924 if (list_empty(&pdo->pdo_head)) {
925 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
927 mutex_lock(&sn->pipefs_sb_lock);
928 ret = rpc_add_pipe_dir_object_locked(net, pdh, pdo);
929 mutex_unlock(&sn->pipefs_sb_lock);
933 EXPORT_SYMBOL_GPL(rpc_add_pipe_dir_object);
936 * rpc_remove_pipe_dir_object - remove a rpc_pipe_dir_object from a directory
937 * @net: pointer to struct net
938 * @pdh: pointer to struct rpc_pipe_dir_head
939 * @pdo: pointer to struct rpc_pipe_dir_object
943 rpc_remove_pipe_dir_object(struct net *net,
944 struct rpc_pipe_dir_head *pdh,
945 struct rpc_pipe_dir_object *pdo)
947 if (!list_empty(&pdo->pdo_head)) {
948 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
950 mutex_lock(&sn->pipefs_sb_lock);
951 rpc_remove_pipe_dir_object_locked(net, pdh, pdo);
952 mutex_unlock(&sn->pipefs_sb_lock);
955 EXPORT_SYMBOL_GPL(rpc_remove_pipe_dir_object);
958 * rpc_find_or_alloc_pipe_dir_object
959 * @net: pointer to struct net
960 * @pdh: pointer to struct rpc_pipe_dir_head
961 * @match: match struct rpc_pipe_dir_object to data
962 * @alloc: allocate a new struct rpc_pipe_dir_object
963 * @data: user defined data for match() and alloc()
966 struct rpc_pipe_dir_object *
967 rpc_find_or_alloc_pipe_dir_object(struct net *net,
968 struct rpc_pipe_dir_head *pdh,
969 int (*match)(struct rpc_pipe_dir_object *, void *),
970 struct rpc_pipe_dir_object *(*alloc)(void *),
973 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
974 struct rpc_pipe_dir_object *pdo;
976 mutex_lock(&sn->pipefs_sb_lock);
977 list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head) {
978 if (!match(pdo, data))
985 rpc_add_pipe_dir_object_locked(net, pdh, pdo);
987 mutex_unlock(&sn->pipefs_sb_lock);
990 EXPORT_SYMBOL_GPL(rpc_find_or_alloc_pipe_dir_object);
993 rpc_create_pipe_dir_objects(struct rpc_pipe_dir_head *pdh)
995 struct rpc_pipe_dir_object *pdo;
996 struct dentry *dir = pdh->pdh_dentry;
998 list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head)
999 pdo->pdo_ops->create(dir, pdo);
1003 rpc_destroy_pipe_dir_objects(struct rpc_pipe_dir_head *pdh)
1005 struct rpc_pipe_dir_object *pdo;
1006 struct dentry *dir = pdh->pdh_dentry;
1008 list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head)
1009 pdo->pdo_ops->destroy(dir, pdo);
1017 static const struct rpc_filelist authfiles[] = {
1020 .i_fop = &rpc_info_operations,
1021 .mode = S_IFREG | 0400,
1025 static int rpc_clntdir_populate(struct dentry *dentry, void *private)
1027 return rpc_populate(dentry,
1028 authfiles, RPCAUTH_info, RPCAUTH_EOF,
1032 static void rpc_clntdir_depopulate(struct dentry *dentry)
1034 rpc_depopulate(dentry, authfiles, RPCAUTH_info, RPCAUTH_EOF);
1038 * rpc_create_client_dir - Create a new rpc_client directory in rpc_pipefs
1039 * @dentry: the parent of new directory
1040 * @name: the name of new directory
1041 * @rpc_client: rpc client to associate with this directory
1043 * This creates a directory at the given @path associated with
1044 * @rpc_clnt, which will contain a file named "info" with some basic
1045 * information about the client, together with any "pipes" that may
1046 * later be created using rpc_mkpipe().
1048 struct dentry *rpc_create_client_dir(struct dentry *dentry,
1050 struct rpc_clnt *rpc_client)
1054 ret = rpc_mkdir_populate(dentry, name, 0555, NULL,
1055 rpc_clntdir_populate, rpc_client);
1057 rpc_client->cl_pipedir_objects.pdh_dentry = ret;
1058 rpc_create_pipe_dir_objects(&rpc_client->cl_pipedir_objects);
1064 * rpc_remove_client_dir - Remove a directory created with rpc_create_client_dir()
1065 * @rpc_client: rpc_client for the pipe
1067 int rpc_remove_client_dir(struct rpc_clnt *rpc_client)
1069 struct dentry *dentry = rpc_client->cl_pipedir_objects.pdh_dentry;
1073 rpc_destroy_pipe_dir_objects(&rpc_client->cl_pipedir_objects);
1074 rpc_client->cl_pipedir_objects.pdh_dentry = NULL;
1075 return rpc_rmdir_depopulate(dentry, rpc_clntdir_depopulate);
1078 static const struct rpc_filelist cache_pipefs_files[3] = {
1081 .i_fop = &cache_file_operations_pipefs,
1082 .mode = S_IFREG | 0600,
1086 .i_fop = &content_file_operations_pipefs,
1087 .mode = S_IFREG | 0400,
1091 .i_fop = &cache_flush_operations_pipefs,
1092 .mode = S_IFREG | 0600,
1096 static int rpc_cachedir_populate(struct dentry *dentry, void *private)
1098 return rpc_populate(dentry,
1099 cache_pipefs_files, 0, 3,
1103 static void rpc_cachedir_depopulate(struct dentry *dentry)
1105 rpc_depopulate(dentry, cache_pipefs_files, 0, 3);
1108 struct dentry *rpc_create_cache_dir(struct dentry *parent, const char *name,
1109 umode_t umode, struct cache_detail *cd)
1111 return rpc_mkdir_populate(parent, name, umode, NULL,
1112 rpc_cachedir_populate, cd);
1115 void rpc_remove_cache_dir(struct dentry *dentry)
1117 rpc_rmdir_depopulate(dentry, rpc_cachedir_depopulate);
1121 * populate the filesystem
1123 static const struct super_operations s_ops = {
1124 .alloc_inode = rpc_alloc_inode,
1125 .free_inode = rpc_free_inode,
1126 .statfs = simple_statfs,
1129 #define RPCAUTH_GSSMAGIC 0x67596969
1132 * We have a single directory with 1 node in it.
1147 static const struct rpc_filelist files[] = {
1150 .mode = S_IFDIR | 0555,
1154 .mode = S_IFDIR | 0555,
1158 .mode = S_IFDIR | 0555,
1160 [RPCAUTH_portmap] = {
1162 .mode = S_IFDIR | 0555,
1166 .mode = S_IFDIR | 0555,
1168 [RPCAUTH_nfsd4_cb] = {
1170 .mode = S_IFDIR | 0555,
1174 .mode = S_IFDIR | 0555,
1178 .mode = S_IFDIR | 0555,
1182 .mode = S_IFDIR | 0555,
1187 * This call can be used only in RPC pipefs mount notification hooks.
1189 struct dentry *rpc_d_lookup_sb(const struct super_block *sb,
1190 const unsigned char *dir_name)
1192 struct qstr dir = QSTR_INIT(dir_name, strlen(dir_name));
1193 return d_hash_and_lookup(sb->s_root, &dir);
1195 EXPORT_SYMBOL_GPL(rpc_d_lookup_sb);
1197 int rpc_pipefs_init_net(struct net *net)
1199 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1201 sn->gssd_dummy = rpc_mkpipe_data(&gssd_dummy_pipe_ops, 0);
1202 if (IS_ERR(sn->gssd_dummy))
1203 return PTR_ERR(sn->gssd_dummy);
1205 mutex_init(&sn->pipefs_sb_lock);
1206 sn->pipe_version = -1;
1210 void rpc_pipefs_exit_net(struct net *net)
1212 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1214 rpc_destroy_pipe_data(sn->gssd_dummy);
1218 * This call will be used for per network namespace operations calls.
1219 * Note: Function will be returned with pipefs_sb_lock taken if superblock was
1220 * found. This lock have to be released by rpc_put_sb_net() when all operations
1221 * will be completed.
1223 struct super_block *rpc_get_sb_net(const struct net *net)
1225 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1227 mutex_lock(&sn->pipefs_sb_lock);
1229 return sn->pipefs_sb;
1230 mutex_unlock(&sn->pipefs_sb_lock);
1233 EXPORT_SYMBOL_GPL(rpc_get_sb_net);
1235 void rpc_put_sb_net(const struct net *net)
1237 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1239 WARN_ON(sn->pipefs_sb == NULL);
1240 mutex_unlock(&sn->pipefs_sb_lock);
1242 EXPORT_SYMBOL_GPL(rpc_put_sb_net);
1244 static const struct rpc_filelist gssd_dummy_clnt_dir[] = {
1247 .mode = S_IFDIR | 0555,
1252 dummy_downcall(struct file *filp, const char __user *src, size_t len)
1257 static const struct rpc_pipe_ops gssd_dummy_pipe_ops = {
1258 .upcall = rpc_pipe_generic_upcall,
1259 .downcall = dummy_downcall,
1263 * Here we present a bogus "info" file to keep rpc.gssd happy. We don't expect
1264 * that it will ever use this info to handle an upcall, but rpc.gssd expects
1265 * that this file will be there and have a certain format.
1268 rpc_dummy_info_show(struct seq_file *m, void *v)
1270 seq_printf(m, "RPC server: %s\n", utsname()->nodename);
1271 seq_printf(m, "service: foo (1) version 0\n");
1272 seq_printf(m, "address: 127.0.0.1\n");
1273 seq_printf(m, "protocol: tcp\n");
1274 seq_printf(m, "port: 0\n");
1277 DEFINE_SHOW_ATTRIBUTE(rpc_dummy_info);
1279 static const struct rpc_filelist gssd_dummy_info_file[] = {
1282 .i_fop = &rpc_dummy_info_fops,
1283 .mode = S_IFREG | 0400,
1288 * rpc_gssd_dummy_populate - create a dummy gssd pipe
1289 * @root: root of the rpc_pipefs filesystem
1290 * @pipe_data: pipe data created when netns is initialized
1292 * Create a dummy set of directories and a pipe that gssd can hold open to
1293 * indicate that it is up and running.
1295 static struct dentry *
1296 rpc_gssd_dummy_populate(struct dentry *root, struct rpc_pipe *pipe_data)
1299 struct dentry *gssd_dentry;
1300 struct dentry *clnt_dentry = NULL;
1301 struct dentry *pipe_dentry = NULL;
1302 struct qstr q = QSTR_INIT(files[RPCAUTH_gssd].name,
1303 strlen(files[RPCAUTH_gssd].name));
1305 /* We should never get this far if "gssd" doesn't exist */
1306 gssd_dentry = d_hash_and_lookup(root, &q);
1308 return ERR_PTR(-ENOENT);
1310 ret = rpc_populate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1, NULL);
1312 pipe_dentry = ERR_PTR(ret);
1316 q.name = gssd_dummy_clnt_dir[0].name;
1317 q.len = strlen(gssd_dummy_clnt_dir[0].name);
1318 clnt_dentry = d_hash_and_lookup(gssd_dentry, &q);
1320 pipe_dentry = ERR_PTR(-ENOENT);
1324 ret = rpc_populate(clnt_dentry, gssd_dummy_info_file, 0, 1, NULL);
1326 __rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1);
1327 pipe_dentry = ERR_PTR(ret);
1331 pipe_dentry = rpc_mkpipe_dentry(clnt_dentry, "gssd", NULL, pipe_data);
1332 if (IS_ERR(pipe_dentry)) {
1333 __rpc_depopulate(clnt_dentry, gssd_dummy_info_file, 0, 1);
1334 __rpc_depopulate(gssd_dentry, gssd_dummy_clnt_dir, 0, 1);
1343 rpc_gssd_dummy_depopulate(struct dentry *pipe_dentry)
1345 struct dentry *clnt_dir = pipe_dentry->d_parent;
1346 struct dentry *gssd_dir = clnt_dir->d_parent;
1349 __rpc_rmpipe(d_inode(clnt_dir), pipe_dentry);
1350 __rpc_depopulate(clnt_dir, gssd_dummy_info_file, 0, 1);
1351 __rpc_depopulate(gssd_dir, gssd_dummy_clnt_dir, 0, 1);
1356 rpc_fill_super(struct super_block *sb, struct fs_context *fc)
1358 struct inode *inode;
1359 struct dentry *root, *gssd_dentry;
1360 struct net *net = sb->s_fs_info;
1361 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1364 sb->s_blocksize = PAGE_SIZE;
1365 sb->s_blocksize_bits = PAGE_SHIFT;
1366 sb->s_magic = RPCAUTH_GSSMAGIC;
1368 sb->s_d_op = &simple_dentry_operations;
1369 sb->s_time_gran = 1;
1371 inode = rpc_get_inode(sb, S_IFDIR | 0555);
1372 sb->s_root = root = d_make_root(inode);
1375 if (rpc_populate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF, NULL))
1378 gssd_dentry = rpc_gssd_dummy_populate(root, sn->gssd_dummy);
1379 if (IS_ERR(gssd_dentry)) {
1380 __rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
1381 return PTR_ERR(gssd_dentry);
1384 dprintk("RPC: sending pipefs MOUNT notification for net %x%s\n",
1385 net->ns.inum, NET_NAME(net));
1386 mutex_lock(&sn->pipefs_sb_lock);
1388 err = blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1392 goto err_depopulate;
1393 mutex_unlock(&sn->pipefs_sb_lock);
1397 rpc_gssd_dummy_depopulate(gssd_dentry);
1398 blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1401 sn->pipefs_sb = NULL;
1402 __rpc_depopulate(root, files, RPCAUTH_lockd, RPCAUTH_RootEOF);
1403 mutex_unlock(&sn->pipefs_sb_lock);
1408 gssd_running(struct net *net)
1410 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1411 struct rpc_pipe *pipe = sn->gssd_dummy;
1413 return pipe->nreaders || pipe->nwriters;
1415 EXPORT_SYMBOL_GPL(gssd_running);
1417 static int rpc_fs_get_tree(struct fs_context *fc)
1419 return get_tree_keyed(fc, rpc_fill_super, get_net(fc->net_ns));
1422 static void rpc_fs_free_fc(struct fs_context *fc)
1425 put_net(fc->s_fs_info);
1428 static const struct fs_context_operations rpc_fs_context_ops = {
1429 .free = rpc_fs_free_fc,
1430 .get_tree = rpc_fs_get_tree,
1433 static int rpc_init_fs_context(struct fs_context *fc)
1435 put_user_ns(fc->user_ns);
1436 fc->user_ns = get_user_ns(fc->net_ns->user_ns);
1437 fc->ops = &rpc_fs_context_ops;
1441 static void rpc_kill_sb(struct super_block *sb)
1443 struct net *net = sb->s_fs_info;
1444 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1446 mutex_lock(&sn->pipefs_sb_lock);
1447 if (sn->pipefs_sb != sb) {
1448 mutex_unlock(&sn->pipefs_sb_lock);
1451 sn->pipefs_sb = NULL;
1452 dprintk("RPC: sending pipefs UMOUNT notification for net %x%s\n",
1453 net->ns.inum, NET_NAME(net));
1454 blocking_notifier_call_chain(&rpc_pipefs_notifier_list,
1457 mutex_unlock(&sn->pipefs_sb_lock);
1459 kill_litter_super(sb);
1463 static struct file_system_type rpc_pipe_fs_type = {
1464 .owner = THIS_MODULE,
1465 .name = "rpc_pipefs",
1466 .init_fs_context = rpc_init_fs_context,
1467 .kill_sb = rpc_kill_sb,
1469 MODULE_ALIAS_FS("rpc_pipefs");
1470 MODULE_ALIAS("rpc_pipefs");
1473 init_once(void *foo)
1475 struct rpc_inode *rpci = (struct rpc_inode *) foo;
1477 inode_init_once(&rpci->vfs_inode);
1478 rpci->private = NULL;
1480 init_waitqueue_head(&rpci->waitq);
1483 int register_rpc_pipefs(void)
1487 rpc_inode_cachep = kmem_cache_create("rpc_inode_cache",
1488 sizeof(struct rpc_inode),
1489 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
1490 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1492 if (!rpc_inode_cachep)
1494 err = rpc_clients_notifier_register();
1497 err = register_filesystem(&rpc_pipe_fs_type);
1503 rpc_clients_notifier_unregister();
1505 kmem_cache_destroy(rpc_inode_cachep);
1509 void unregister_rpc_pipefs(void)
1511 rpc_clients_notifier_unregister();
1512 kmem_cache_destroy(rpc_inode_cachep);
1513 unregister_filesystem(&rpc_pipe_fs_type);