tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
36static void
37nfs4_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
51dev_t
52bl_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);
104out_free_data:
105 kfree(msg->data);
106out_unlock:
107 mutex_unlock(&nn->bl_mutex);
108 return dev;
109}
110
111static 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
128static 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
138static 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
144static int nfs4blocklayout_register_sb(struct super_block *sb,
145 struct rpc_pipe *pipe)
146{
147 struct dentry *dir;
148 int err;
149
150 dir = rpc_d_lookup_sb(sb, NFS_PIPE_DIRNAME);
151 if (dir == NULL)
152 return -ENOENT;
153 err = rpc_mkpipe_dentry(dir, "blocklayout", NULL, pipe);
154 dput(dir);
155 return err;
156}
157
158static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
159 void *ptr)
160{
161 struct super_block *sb = ptr;
162 struct net *net = sb->s_fs_info;
163 struct nfs_net *nn = net_generic(net, nfs_net_id);
164 int ret = 0;
165
166 if (!try_module_get(THIS_MODULE))
167 return 0;
168
169 if (nn->bl_device_pipe == NULL) {
170 module_put(THIS_MODULE);
171 return 0;
172 }
173
174 switch (event) {
175 case RPC_PIPEFS_MOUNT:
176 ret = nfs4blocklayout_register_sb(sb, nn->bl_device_pipe);
177 break;
178 case RPC_PIPEFS_UMOUNT:
179 rpc_unlink(nn->bl_device_pipe);
180 break;
181 default:
182 ret = -ENOTSUPP;
183 break;
184 }
185 module_put(THIS_MODULE);
186 return ret;
187}
188
189static struct notifier_block nfs4blocklayout_block = {
190 .notifier_call = rpc_pipefs_event,
191};
192
193static int nfs4blocklayout_register_net(struct net *net, struct rpc_pipe *pipe)
194{
195 struct super_block *pipefs_sb;
196 int ret;
197
198 pipefs_sb = rpc_get_sb_net(net);
199 if (!pipefs_sb)
200 return 0;
201 ret = nfs4blocklayout_register_sb(pipefs_sb, pipe);
202 rpc_put_sb_net(net);
203 return ret;
204}
205
206static void nfs4blocklayout_unregister_net(struct net *net,
207 struct rpc_pipe *pipe)
208{
209 struct super_block *pipefs_sb;
210
211 pipefs_sb = rpc_get_sb_net(net);
212 if (pipefs_sb) {
213 rpc_unlink(pipe);
214 rpc_put_sb_net(net);
215 }
216}
217
218static int nfs4blocklayout_net_init(struct net *net)
219{
220 struct nfs_net *nn = net_generic(net, nfs_net_id);
221 int err;
222
223 mutex_init(&nn->bl_mutex);
224 init_waitqueue_head(&nn->bl_wq);
225 nn->bl_device_pipe = rpc_mkpipe_data(&bl_upcall_ops, 0);
226 if (IS_ERR(nn->bl_device_pipe))
227 return PTR_ERR(nn->bl_device_pipe);
228 err = nfs4blocklayout_register_net(net, nn->bl_device_pipe);
229 if (unlikely(err))
230 rpc_destroy_pipe_data(nn->bl_device_pipe);
231 return err;
232}
233
234static void nfs4blocklayout_net_exit(struct net *net)
235{
236 struct nfs_net *nn = net_generic(net, nfs_net_id);
237
238 nfs4blocklayout_unregister_net(net, nn->bl_device_pipe);
239 rpc_destroy_pipe_data(nn->bl_device_pipe);
240 nn->bl_device_pipe = NULL;
241}
242
243static struct pernet_operations nfs4blocklayout_net_ops = {
244 .init = nfs4blocklayout_net_init,
245 .exit = nfs4blocklayout_net_exit,
246};
247
248int __init bl_init_pipefs(void)
249{
250 int ret;
251
252 ret = rpc_pipefs_notifier_register(&nfs4blocklayout_block);
253 if (ret)
254 goto out;
255 ret = register_pernet_subsys(&nfs4blocklayout_net_ops);
256 if (ret)
257 goto out_unregister_notifier;
258 return 0;
259
260out_unregister_notifier:
261 rpc_pipefs_notifier_unregister(&nfs4blocklayout_block);
262out:
263 return ret;
264}
265
266void bl_cleanup_pipefs(void)
267{
268 rpc_pipefs_notifier_unregister(&nfs4blocklayout_block);
269 unregister_pernet_subsys(&nfs4blocklayout_net_ops);
270}