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
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
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_unlock;
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
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
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
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
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
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
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
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
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
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
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
283 void bl_cleanup_pipefs(void)
284 {
285 rpc_pipefs_notifier_unregister(&nfs4blocklayout_block);
286 unregister_pernet_subsys(&nfs4blocklayout_net_ops);
287 }
288
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