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/genhd.h> 31 #include <linux/blkdev.h> 32 33 #include "blocklayout.h" 34 35 #define NFSDBG_FACILITY NFSDBG_PNFS_LD 36 37 static void 38 nfs4_encode_simple(__be32 *p, struct pnfs_block_volume *b) 39 { 40 int i; 41 42 *p++ = cpu_to_be32(1); 43 *p++ = cpu_to_be32(b->type); 44 *p++ = cpu_to_be32(b->simple.nr_sigs); 45 for (i = 0; i < b->simple.nr_sigs; i++) { 46 p = xdr_encode_hyper(p, b->simple.sigs[i].offset); 47 p = xdr_encode_opaque(p, b->simple.sigs[i].sig, 48 b->simple.sigs[i].sig_len); 49 } 50 } 51 52 dev_t 53 bl_resolve_deviceid(struct nfs_server *server, struct pnfs_block_volume *b, 54 gfp_t gfp_mask) 55 { 56 struct net *net = server->nfs_client->cl_net; 57 struct nfs_net *nn = net_generic(net, nfs_net_id); 58 struct bl_dev_msg *reply = &nn->bl_mount_reply; 59 struct bl_pipe_msg bl_pipe_msg; 60 struct rpc_pipe_msg *msg = &bl_pipe_msg.msg; 61 struct bl_msg_hdr *bl_msg; 62 DECLARE_WAITQUEUE(wq, current); 63 dev_t dev = 0; 64 int rc; 65 66 dprintk("%s CREATING PIPEFS MESSAGE\n", __func__); 67 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 return -EIO; 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; 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; 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; 101 } 102 103 dev = MKDEV(reply->major, reply->minor); 104 out: 105 kfree(msg->data); 106 return dev; 107 } 108 109 static ssize_t bl_pipe_downcall(struct file *filp, const char __user *src, 110 size_t mlen) 111 { 112 struct nfs_net *nn = net_generic(filp->f_dentry->d_sb->s_fs_info, 113 nfs_net_id); 114 115 if (mlen != sizeof (struct bl_dev_msg)) 116 return -EINVAL; 117 118 if (copy_from_user(&nn->bl_mount_reply, src, mlen) != 0) 119 return -EFAULT; 120 121 wake_up(&nn->bl_wq); 122 123 return mlen; 124 } 125 126 static void bl_pipe_destroy_msg(struct rpc_pipe_msg *msg) 127 { 128 struct bl_pipe_msg *bl_pipe_msg = 129 container_of(msg, struct bl_pipe_msg, msg); 130 131 if (msg->errno >= 0) 132 return; 133 wake_up(bl_pipe_msg->bl_wq); 134 } 135 136 static const struct rpc_pipe_ops bl_upcall_ops = { 137 .upcall = rpc_pipe_generic_upcall, 138 .downcall = bl_pipe_downcall, 139 .destroy_msg = bl_pipe_destroy_msg, 140 }; 141 142 static struct dentry *nfs4blocklayout_register_sb(struct super_block *sb, 143 struct rpc_pipe *pipe) 144 { 145 struct dentry *dir, *dentry; 146 147 dir = rpc_d_lookup_sb(sb, NFS_PIPE_DIRNAME); 148 if (dir == NULL) 149 return ERR_PTR(-ENOENT); 150 dentry = rpc_mkpipe_dentry(dir, "blocklayout", NULL, pipe); 151 dput(dir); 152 return dentry; 153 } 154 155 static void nfs4blocklayout_unregister_sb(struct super_block *sb, 156 struct rpc_pipe *pipe) 157 { 158 if (pipe->dentry) 159 rpc_unlink(pipe->dentry); 160 } 161 162 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event, 163 void *ptr) 164 { 165 struct super_block *sb = ptr; 166 struct net *net = sb->s_fs_info; 167 struct nfs_net *nn = net_generic(net, nfs_net_id); 168 struct dentry *dentry; 169 int ret = 0; 170 171 if (!try_module_get(THIS_MODULE)) 172 return 0; 173 174 if (nn->bl_device_pipe == NULL) { 175 module_put(THIS_MODULE); 176 return 0; 177 } 178 179 switch (event) { 180 case RPC_PIPEFS_MOUNT: 181 dentry = nfs4blocklayout_register_sb(sb, nn->bl_device_pipe); 182 if (IS_ERR(dentry)) { 183 ret = PTR_ERR(dentry); 184 break; 185 } 186 nn->bl_device_pipe->dentry = dentry; 187 break; 188 case RPC_PIPEFS_UMOUNT: 189 if (nn->bl_device_pipe->dentry) 190 nfs4blocklayout_unregister_sb(sb, nn->bl_device_pipe); 191 break; 192 default: 193 ret = -ENOTSUPP; 194 break; 195 } 196 module_put(THIS_MODULE); 197 return ret; 198 } 199 200 static struct notifier_block nfs4blocklayout_block = { 201 .notifier_call = rpc_pipefs_event, 202 }; 203 204 static struct dentry *nfs4blocklayout_register_net(struct net *net, 205 struct rpc_pipe *pipe) 206 { 207 struct super_block *pipefs_sb; 208 struct dentry *dentry; 209 210 pipefs_sb = rpc_get_sb_net(net); 211 if (!pipefs_sb) 212 return NULL; 213 dentry = nfs4blocklayout_register_sb(pipefs_sb, pipe); 214 rpc_put_sb_net(net); 215 return dentry; 216 } 217 218 static void nfs4blocklayout_unregister_net(struct net *net, 219 struct rpc_pipe *pipe) 220 { 221 struct super_block *pipefs_sb; 222 223 pipefs_sb = rpc_get_sb_net(net); 224 if (pipefs_sb) { 225 nfs4blocklayout_unregister_sb(pipefs_sb, pipe); 226 rpc_put_sb_net(net); 227 } 228 } 229 230 static int nfs4blocklayout_net_init(struct net *net) 231 { 232 struct nfs_net *nn = net_generic(net, nfs_net_id); 233 struct dentry *dentry; 234 235 init_waitqueue_head(&nn->bl_wq); 236 nn->bl_device_pipe = rpc_mkpipe_data(&bl_upcall_ops, 0); 237 if (IS_ERR(nn->bl_device_pipe)) 238 return PTR_ERR(nn->bl_device_pipe); 239 dentry = nfs4blocklayout_register_net(net, nn->bl_device_pipe); 240 if (IS_ERR(dentry)) { 241 rpc_destroy_pipe_data(nn->bl_device_pipe); 242 return PTR_ERR(dentry); 243 } 244 nn->bl_device_pipe->dentry = dentry; 245 return 0; 246 } 247 248 static void nfs4blocklayout_net_exit(struct net *net) 249 { 250 struct nfs_net *nn = net_generic(net, nfs_net_id); 251 252 nfs4blocklayout_unregister_net(net, nn->bl_device_pipe); 253 rpc_destroy_pipe_data(nn->bl_device_pipe); 254 nn->bl_device_pipe = NULL; 255 } 256 257 static struct pernet_operations nfs4blocklayout_net_ops = { 258 .init = nfs4blocklayout_net_init, 259 .exit = nfs4blocklayout_net_exit, 260 }; 261 262 int __init bl_init_pipefs(void) 263 { 264 int ret; 265 266 ret = rpc_pipefs_notifier_register(&nfs4blocklayout_block); 267 if (ret) 268 goto out; 269 ret = register_pernet_subsys(&nfs4blocklayout_net_ops); 270 if (ret) 271 goto out_unregister_notifier; 272 return 0; 273 274 out_unregister_notifier: 275 rpc_pipefs_notifier_unregister(&nfs4blocklayout_block); 276 out: 277 return ret; 278 } 279 280 void __exit bl_cleanup_pipefs(void) 281 { 282 rpc_pipefs_notifier_unregister(&nfs4blocklayout_block); 283 unregister_pernet_subsys(&nfs4blocklayout_net_ops); 284 } 285