1 /*
2  *  Copyright (c) 2006,2007 The Regents of the University of Michigan.
3  *  All rights reserved.
4  *
5  *  Andy Adamson <andros@citi.umich.edu>
6  *  Fred Isaman <iisaman@umich.edu>
7  *
8  * permission is granted to use, copy, create derivative works and
9  * redistribute this software and such derivative works for any purpose,
10  * so long as the name of the university of michigan is not used in
11  * any advertising or publicity pertaining to the use or distribution
12  * of this software without specific, written prior authorization.  if
13  * the above copyright notice or any other identification of the
14  * university of michigan is included in any copy of any portion of
15  * this software, then the disclaimer below must also be included.
16  *
17  * this software is provided as is, without representation from the
18  * university of michigan as to its fitness for any purpose, and without
19  * warranty by the university of michigan of any kind, either express
20  * or implied, including without limitation the implied warranties of
21  * merchantability and fitness for a particular purpose.  the regents
22  * of the university of michigan shall not be liable for any damages,
23  * including special, indirect, incidental, or consequential damages,
24  * with respect to any claim arising out or in connection with the use
25  * of the software, even if it has been or is hereafter advised of the
26  * possibility of such damages.
27  */
28 
29 #include <linux/module.h>
30 #include <linux/blkdev.h>
31 
32 #include "blocklayout.h"
33 
34 #define NFSDBG_FACILITY         NFSDBG_PNFS_LD
35 
36 static void
nfs4_encode_simple(__be32 * p,struct pnfs_block_volume * b)37 nfs4_encode_simple(__be32 *p, struct pnfs_block_volume *b)
38 {
39 	int i;
40 
41 	*p++ = cpu_to_be32(1);
42 	*p++ = cpu_to_be32(b->type);
43 	*p++ = cpu_to_be32(b->simple.nr_sigs);
44 	for (i = 0; i < b->simple.nr_sigs; i++) {
45 		p = xdr_encode_hyper(p, b->simple.sigs[i].offset);
46 		p = xdr_encode_opaque(p, b->simple.sigs[i].sig,
47 					 b->simple.sigs[i].sig_len);
48 	}
49 }
50 
51 dev_t
bl_resolve_deviceid(struct nfs_server * server,struct pnfs_block_volume * b,gfp_t gfp_mask)52 bl_resolve_deviceid(struct nfs_server *server, struct pnfs_block_volume *b,
53 		gfp_t gfp_mask)
54 {
55 	struct net *net = server->nfs_client->cl_net;
56 	struct nfs_net *nn = net_generic(net, nfs_net_id);
57 	struct bl_dev_msg *reply = &nn->bl_mount_reply;
58 	struct bl_pipe_msg bl_pipe_msg;
59 	struct rpc_pipe_msg *msg = &bl_pipe_msg.msg;
60 	struct bl_msg_hdr *bl_msg;
61 	DECLARE_WAITQUEUE(wq, current);
62 	dev_t dev = 0;
63 	int rc;
64 
65 	dprintk("%s CREATING PIPEFS MESSAGE\n", __func__);
66 
67 	mutex_lock(&nn->bl_mutex);
68 	bl_pipe_msg.bl_wq = &nn->bl_wq;
69 
70 	b->simple.len += 4;	/* single volume */
71 	if (b->simple.len > PAGE_SIZE)
72 		goto out_unlock;
73 
74 	memset(msg, 0, sizeof(*msg));
75 	msg->len = sizeof(*bl_msg) + b->simple.len;
76 	msg->data = kzalloc(msg->len, gfp_mask);
77 	if (!msg->data)
78 		goto out_free_data;
79 
80 	bl_msg = msg->data;
81 	bl_msg->type = BL_DEVICE_MOUNT;
82 	bl_msg->totallen = b->simple.len;
83 	nfs4_encode_simple(msg->data + sizeof(*bl_msg), b);
84 
85 	dprintk("%s CALLING USERSPACE DAEMON\n", __func__);
86 	add_wait_queue(&nn->bl_wq, &wq);
87 	rc = rpc_queue_upcall(nn->bl_device_pipe, msg);
88 	if (rc < 0) {
89 		remove_wait_queue(&nn->bl_wq, &wq);
90 		goto out_free_data;
91 	}
92 
93 	set_current_state(TASK_UNINTERRUPTIBLE);
94 	schedule();
95 	remove_wait_queue(&nn->bl_wq, &wq);
96 
97 	if (reply->status != BL_DEVICE_REQUEST_PROC) {
98 		printk(KERN_WARNING "%s failed to decode device: %d\n",
99 			__func__, reply->status);
100 		goto out_free_data;
101 	}
102 
103 	dev = MKDEV(reply->major, reply->minor);
104 out_free_data:
105 	kfree(msg->data);
106 out_unlock:
107 	mutex_unlock(&nn->bl_mutex);
108 	return dev;
109 }
110 
bl_pipe_downcall(struct file * filp,const char __user * src,size_t mlen)111 static ssize_t bl_pipe_downcall(struct file *filp, const char __user *src,
112 			 size_t mlen)
113 {
114 	struct nfs_net *nn = net_generic(file_inode(filp)->i_sb->s_fs_info,
115 					 nfs_net_id);
116 
117 	if (mlen != sizeof (struct bl_dev_msg))
118 		return -EINVAL;
119 
120 	if (copy_from_user(&nn->bl_mount_reply, src, mlen) != 0)
121 		return -EFAULT;
122 
123 	wake_up(&nn->bl_wq);
124 
125 	return mlen;
126 }
127 
bl_pipe_destroy_msg(struct rpc_pipe_msg * msg)128 static void bl_pipe_destroy_msg(struct rpc_pipe_msg *msg)
129 {
130 	struct bl_pipe_msg *bl_pipe_msg =
131 		container_of(msg, struct bl_pipe_msg, msg);
132 
133 	if (msg->errno >= 0)
134 		return;
135 	wake_up(bl_pipe_msg->bl_wq);
136 }
137 
138 static const struct rpc_pipe_ops bl_upcall_ops = {
139 	.upcall		= rpc_pipe_generic_upcall,
140 	.downcall	= bl_pipe_downcall,
141 	.destroy_msg	= bl_pipe_destroy_msg,
142 };
143 
nfs4blocklayout_register_sb(struct super_block * sb,struct rpc_pipe * pipe)144 static struct dentry *nfs4blocklayout_register_sb(struct super_block *sb,
145 					    struct rpc_pipe *pipe)
146 {
147 	struct dentry *dir, *dentry;
148 
149 	dir = rpc_d_lookup_sb(sb, NFS_PIPE_DIRNAME);
150 	if (dir == NULL)
151 		return ERR_PTR(-ENOENT);
152 	dentry = rpc_mkpipe_dentry(dir, "blocklayout", NULL, pipe);
153 	dput(dir);
154 	return dentry;
155 }
156 
nfs4blocklayout_unregister_sb(struct super_block * sb,struct rpc_pipe * pipe)157 static void nfs4blocklayout_unregister_sb(struct super_block *sb,
158 					  struct rpc_pipe *pipe)
159 {
160 	if (pipe->dentry)
161 		rpc_unlink(pipe->dentry);
162 }
163 
rpc_pipefs_event(struct notifier_block * nb,unsigned long event,void * ptr)164 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
165 			   void *ptr)
166 {
167 	struct super_block *sb = ptr;
168 	struct net *net = sb->s_fs_info;
169 	struct nfs_net *nn = net_generic(net, nfs_net_id);
170 	struct dentry *dentry;
171 	int ret = 0;
172 
173 	if (!try_module_get(THIS_MODULE))
174 		return 0;
175 
176 	if (nn->bl_device_pipe == NULL) {
177 		module_put(THIS_MODULE);
178 		return 0;
179 	}
180 
181 	switch (event) {
182 	case RPC_PIPEFS_MOUNT:
183 		dentry = nfs4blocklayout_register_sb(sb, nn->bl_device_pipe);
184 		if (IS_ERR(dentry)) {
185 			ret = PTR_ERR(dentry);
186 			break;
187 		}
188 		nn->bl_device_pipe->dentry = dentry;
189 		break;
190 	case RPC_PIPEFS_UMOUNT:
191 		if (nn->bl_device_pipe->dentry)
192 			nfs4blocklayout_unregister_sb(sb, nn->bl_device_pipe);
193 		break;
194 	default:
195 		ret = -ENOTSUPP;
196 		break;
197 	}
198 	module_put(THIS_MODULE);
199 	return ret;
200 }
201 
202 static struct notifier_block nfs4blocklayout_block = {
203 	.notifier_call = rpc_pipefs_event,
204 };
205 
nfs4blocklayout_register_net(struct net * net,struct rpc_pipe * pipe)206 static struct dentry *nfs4blocklayout_register_net(struct net *net,
207 						   struct rpc_pipe *pipe)
208 {
209 	struct super_block *pipefs_sb;
210 	struct dentry *dentry;
211 
212 	pipefs_sb = rpc_get_sb_net(net);
213 	if (!pipefs_sb)
214 		return NULL;
215 	dentry = nfs4blocklayout_register_sb(pipefs_sb, pipe);
216 	rpc_put_sb_net(net);
217 	return dentry;
218 }
219 
nfs4blocklayout_unregister_net(struct net * net,struct rpc_pipe * pipe)220 static void nfs4blocklayout_unregister_net(struct net *net,
221 					   struct rpc_pipe *pipe)
222 {
223 	struct super_block *pipefs_sb;
224 
225 	pipefs_sb = rpc_get_sb_net(net);
226 	if (pipefs_sb) {
227 		nfs4blocklayout_unregister_sb(pipefs_sb, pipe);
228 		rpc_put_sb_net(net);
229 	}
230 }
231 
nfs4blocklayout_net_init(struct net * net)232 static int nfs4blocklayout_net_init(struct net *net)
233 {
234 	struct nfs_net *nn = net_generic(net, nfs_net_id);
235 	struct dentry *dentry;
236 
237 	mutex_init(&nn->bl_mutex);
238 	init_waitqueue_head(&nn->bl_wq);
239 	nn->bl_device_pipe = rpc_mkpipe_data(&bl_upcall_ops, 0);
240 	if (IS_ERR(nn->bl_device_pipe))
241 		return PTR_ERR(nn->bl_device_pipe);
242 	dentry = nfs4blocklayout_register_net(net, nn->bl_device_pipe);
243 	if (IS_ERR(dentry)) {
244 		rpc_destroy_pipe_data(nn->bl_device_pipe);
245 		return PTR_ERR(dentry);
246 	}
247 	nn->bl_device_pipe->dentry = dentry;
248 	return 0;
249 }
250 
nfs4blocklayout_net_exit(struct net * net)251 static void nfs4blocklayout_net_exit(struct net *net)
252 {
253 	struct nfs_net *nn = net_generic(net, nfs_net_id);
254 
255 	nfs4blocklayout_unregister_net(net, nn->bl_device_pipe);
256 	rpc_destroy_pipe_data(nn->bl_device_pipe);
257 	nn->bl_device_pipe = NULL;
258 }
259 
260 static struct pernet_operations nfs4blocklayout_net_ops = {
261 	.init = nfs4blocklayout_net_init,
262 	.exit = nfs4blocklayout_net_exit,
263 };
264 
bl_init_pipefs(void)265 int __init bl_init_pipefs(void)
266 {
267 	int ret;
268 
269 	ret = rpc_pipefs_notifier_register(&nfs4blocklayout_block);
270 	if (ret)
271 		goto out;
272 	ret = register_pernet_subsys(&nfs4blocklayout_net_ops);
273 	if (ret)
274 		goto out_unregister_notifier;
275 	return 0;
276 
277 out_unregister_notifier:
278 	rpc_pipefs_notifier_unregister(&nfs4blocklayout_block);
279 out:
280 	return ret;
281 }
282 
bl_cleanup_pipefs(void)283 void bl_cleanup_pipefs(void)
284 {
285 	rpc_pipefs_notifier_unregister(&nfs4blocklayout_block);
286 	unregister_pernet_subsys(&nfs4blocklayout_net_ops);
287 }
288