Joel Becker | 8adf053 | 2007-11-28 14:38:40 -0800 | [diff] [blame] | 1 | /* -*- mode: c; c-basic-offset: 8; -*- |
| 2 | * vim: noexpandtab sw=8 ts=8 sts=0: |
| 3 | * |
| 4 | * stack_user.c |
| 5 | * |
| 6 | * Code which interfaces ocfs2 with fs/dlm and a userspace stack. |
| 7 | * |
| 8 | * Copyright (C) 2007 Oracle. All rights reserved. |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or |
| 11 | * modify it under the terms of the GNU General Public |
| 12 | * License as published by the Free Software Foundation, version 2. |
| 13 | * |
| 14 | * This program is distributed in the hope that it will be useful, |
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 17 | * General Public License for more details. |
| 18 | */ |
| 19 | |
| 20 | #include <linux/module.h> |
Joel Becker | 6427a72 | 2008-02-18 19:23:28 -0800 | [diff] [blame] | 21 | #include <linux/fs.h> |
| 22 | #include <linux/miscdevice.h> |
| 23 | #include <linux/mutex.h> |
| 24 | #include <linux/reboot.h> |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 25 | #include <asm/uaccess.h> |
Joel Becker | 8adf053 | 2007-11-28 14:38:40 -0800 | [diff] [blame] | 26 | |
| 27 | #include "stackglue.h" |
| 28 | |
| 29 | |
Joel Becker | 6427a72 | 2008-02-18 19:23:28 -0800 | [diff] [blame] | 30 | /* |
| 31 | * The control protocol starts with a handshake. Until the handshake |
| 32 | * is complete, the control device will fail all write(2)s. |
| 33 | * |
| 34 | * The handshake is simple. First, the client reads until EOF. Each line |
| 35 | * of output is a supported protocol tag. All protocol tags are a single |
| 36 | * character followed by a two hex digit version number. Currently the |
| 37 | * only things supported is T01, for "Text-base version 0x01". Next, the |
Joel Becker | de870ef | 2008-02-18 17:07:09 -0800 | [diff] [blame] | 38 | * client writes the version they would like to use, including the newline. |
| 39 | * Thus, the protocol tag is 'T01\n'. If the version tag written is |
| 40 | * unknown, -EINVAL is returned. Once the negotiation is complete, the |
| 41 | * client can start sending messages. |
| 42 | * |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 43 | * The T01 protocol only has two messages. First is the "SETN" message. |
| 44 | * It has the following syntax: |
| 45 | * |
| 46 | * SETN<space><8-char-hex-nodenum><newline> |
| 47 | * |
| 48 | * This is 14 characters. |
| 49 | * |
| 50 | * The "SETN" message must be the first message following the protocol. |
| 51 | * It tells ocfs2_control the local node number. |
| 52 | * |
| 53 | * Once the local node number has been set, the "DOWN" message can be |
| 54 | * sent for node down notification. It has the following syntax: |
Joel Becker | de870ef | 2008-02-18 17:07:09 -0800 | [diff] [blame] | 55 | * |
| 56 | * DOWN<space><32-char-cap-hex-uuid><space><8-char-hex-nodenum><newline> |
| 57 | * |
| 58 | * eg: |
| 59 | * |
| 60 | * DOWN 632A924FDD844190BDA93C0DF6B94899 00000001\n |
| 61 | * |
| 62 | * This is 47 characters. |
Joel Becker | 6427a72 | 2008-02-18 19:23:28 -0800 | [diff] [blame] | 63 | */ |
| 64 | |
| 65 | /* |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 66 | * Whether or not the client has done the handshake. |
| 67 | * For now, we have just one protocol version. |
| 68 | */ |
| 69 | #define OCFS2_CONTROL_PROTO "T01\n" |
| 70 | #define OCFS2_CONTROL_PROTO_LEN 4 |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 71 | |
| 72 | /* Handshake states */ |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 73 | #define OCFS2_CONTROL_HANDSHAKE_INVALID (0) |
| 74 | #define OCFS2_CONTROL_HANDSHAKE_READ (1) |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 75 | #define OCFS2_CONTROL_HANDSHAKE_PROTOCOL (2) |
| 76 | #define OCFS2_CONTROL_HANDSHAKE_VALID (3) |
| 77 | |
| 78 | /* Messages */ |
| 79 | #define OCFS2_CONTROL_MESSAGE_OP_LEN 4 |
| 80 | #define OCFS2_CONTROL_MESSAGE_SETNODE_OP "SETN" |
| 81 | #define OCFS2_CONTROL_MESSAGE_SETNODE_TOTAL_LEN 14 |
| 82 | #define OCFS2_CONTROL_MESSAGE_DOWN_OP "DOWN" |
Joel Becker | de870ef | 2008-02-18 17:07:09 -0800 | [diff] [blame] | 83 | #define OCFS2_CONTROL_MESSAGE_DOWN_TOTAL_LEN 47 |
| 84 | #define OCFS2_TEXT_UUID_LEN 32 |
| 85 | #define OCFS2_CONTROL_MESSAGE_NODENUM_LEN 8 |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 86 | |
| 87 | /* |
Joel Becker | 6427a72 | 2008-02-18 19:23:28 -0800 | [diff] [blame] | 88 | * ocfs2_live_connection is refcounted because the filesystem and |
| 89 | * miscdevice sides can detach in different order. Let's just be safe. |
| 90 | */ |
| 91 | struct ocfs2_live_connection { |
| 92 | struct list_head oc_list; |
| 93 | struct ocfs2_cluster_connection *oc_conn; |
| 94 | }; |
| 95 | |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 96 | struct ocfs2_control_private { |
| 97 | struct list_head op_list; |
| 98 | int op_state; |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 99 | int op_this_node; |
| 100 | }; |
| 101 | |
| 102 | /* SETN<space><8-char-hex-nodenum><newline> */ |
| 103 | struct ocfs2_control_message_setn { |
| 104 | char tag[OCFS2_CONTROL_MESSAGE_OP_LEN]; |
| 105 | char space; |
| 106 | char nodestr[OCFS2_CONTROL_MESSAGE_NODENUM_LEN]; |
| 107 | char newline; |
| 108 | }; |
| 109 | |
| 110 | /* DOWN<space><32-char-cap-hex-uuid><space><8-char-hex-nodenum><newline> */ |
| 111 | struct ocfs2_control_message_down { |
| 112 | char tag[OCFS2_CONTROL_MESSAGE_OP_LEN]; |
| 113 | char space1; |
| 114 | char uuid[OCFS2_TEXT_UUID_LEN]; |
| 115 | char space2; |
| 116 | char nodestr[OCFS2_CONTROL_MESSAGE_NODENUM_LEN]; |
| 117 | char newline; |
| 118 | }; |
| 119 | |
| 120 | union ocfs2_control_message { |
| 121 | char tag[OCFS2_CONTROL_MESSAGE_OP_LEN]; |
| 122 | struct ocfs2_control_message_setn u_setn; |
| 123 | struct ocfs2_control_message_down u_down; |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 124 | }; |
| 125 | |
Joel Becker | 6427a72 | 2008-02-18 19:23:28 -0800 | [diff] [blame] | 126 | static atomic_t ocfs2_control_opened; |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 127 | static int ocfs2_control_this_node = -1; |
Joel Becker | 6427a72 | 2008-02-18 19:23:28 -0800 | [diff] [blame] | 128 | |
| 129 | static LIST_HEAD(ocfs2_live_connection_list); |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 130 | static LIST_HEAD(ocfs2_control_private_list); |
Joel Becker | 6427a72 | 2008-02-18 19:23:28 -0800 | [diff] [blame] | 131 | static DEFINE_MUTEX(ocfs2_control_lock); |
| 132 | |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 133 | static inline void ocfs2_control_set_handshake_state(struct file *file, |
| 134 | int state) |
| 135 | { |
| 136 | struct ocfs2_control_private *p = file->private_data; |
| 137 | p->op_state = state; |
| 138 | } |
| 139 | |
| 140 | static inline int ocfs2_control_get_handshake_state(struct file *file) |
| 141 | { |
| 142 | struct ocfs2_control_private *p = file->private_data; |
| 143 | return p->op_state; |
| 144 | } |
| 145 | |
Joel Becker | 6427a72 | 2008-02-18 19:23:28 -0800 | [diff] [blame] | 146 | static struct ocfs2_live_connection *ocfs2_connection_find(const char *name) |
| 147 | { |
| 148 | size_t len = strlen(name); |
| 149 | struct ocfs2_live_connection *c; |
| 150 | |
| 151 | BUG_ON(!mutex_is_locked(&ocfs2_control_lock)); |
| 152 | |
| 153 | list_for_each_entry(c, &ocfs2_live_connection_list, oc_list) { |
| 154 | if ((c->oc_conn->cc_namelen == len) && |
| 155 | !strncmp(c->oc_conn->cc_name, name, len)) |
| 156 | return c; |
| 157 | } |
| 158 | |
| 159 | return c; |
| 160 | } |
| 161 | |
| 162 | /* |
| 163 | * ocfs2_live_connection structures are created underneath the ocfs2 |
| 164 | * mount path. Since the VFS prevents multiple calls to |
| 165 | * fill_super(), we can't get dupes here. |
| 166 | */ |
| 167 | static int ocfs2_live_connection_new(struct ocfs2_cluster_connection *conn, |
| 168 | struct ocfs2_live_connection **c_ret) |
| 169 | { |
| 170 | int rc = 0; |
| 171 | struct ocfs2_live_connection *c; |
| 172 | |
| 173 | c = kzalloc(sizeof(struct ocfs2_live_connection), GFP_KERNEL); |
| 174 | if (!c) |
| 175 | return -ENOMEM; |
| 176 | |
| 177 | mutex_lock(&ocfs2_control_lock); |
| 178 | c->oc_conn = conn; |
| 179 | |
| 180 | if (atomic_read(&ocfs2_control_opened)) |
| 181 | list_add(&c->oc_list, &ocfs2_live_connection_list); |
| 182 | else { |
| 183 | printk(KERN_ERR |
| 184 | "ocfs2: Userspace control daemon is not present\n"); |
| 185 | rc = -ESRCH; |
| 186 | } |
| 187 | |
| 188 | mutex_unlock(&ocfs2_control_lock); |
| 189 | |
| 190 | if (!rc) |
| 191 | *c_ret = c; |
| 192 | else |
| 193 | kfree(c); |
| 194 | |
| 195 | return rc; |
| 196 | } |
| 197 | |
| 198 | /* |
| 199 | * This function disconnects the cluster connection from ocfs2_control. |
| 200 | * Afterwards, userspace can't affect the cluster connection. |
| 201 | */ |
| 202 | static void ocfs2_live_connection_drop(struct ocfs2_live_connection *c) |
| 203 | { |
| 204 | mutex_lock(&ocfs2_control_lock); |
| 205 | list_del_init(&c->oc_list); |
| 206 | c->oc_conn = NULL; |
| 207 | mutex_unlock(&ocfs2_control_lock); |
| 208 | |
| 209 | kfree(c); |
| 210 | } |
| 211 | |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 212 | static int ocfs2_control_cfu(void *target, size_t target_len, |
| 213 | const char __user *buf, size_t count) |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 214 | { |
| 215 | /* The T01 expects write(2) calls to have exactly one command */ |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 216 | if ((count != target_len) || |
| 217 | (count > sizeof(union ocfs2_control_message))) |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 218 | return -EINVAL; |
| 219 | |
| 220 | if (copy_from_user(target, buf, target_len)) |
| 221 | return -EFAULT; |
| 222 | |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 223 | return 0; |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 224 | } |
| 225 | |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 226 | static ssize_t ocfs2_control_validate_protocol(struct file *file, |
| 227 | const char __user *buf, |
| 228 | size_t count) |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 229 | { |
| 230 | ssize_t ret; |
| 231 | char kbuf[OCFS2_CONTROL_PROTO_LEN]; |
| 232 | |
| 233 | ret = ocfs2_control_cfu(kbuf, OCFS2_CONTROL_PROTO_LEN, |
| 234 | buf, count); |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 235 | if (ret) |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 236 | return ret; |
| 237 | |
| 238 | if (strncmp(kbuf, OCFS2_CONTROL_PROTO, OCFS2_CONTROL_PROTO_LEN)) |
| 239 | return -EINVAL; |
| 240 | |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 241 | ocfs2_control_set_handshake_state(file, |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 242 | OCFS2_CONTROL_HANDSHAKE_PROTOCOL); |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 243 | |
| 244 | return count; |
| 245 | } |
| 246 | |
Joel Becker | de870ef | 2008-02-18 17:07:09 -0800 | [diff] [blame] | 247 | static void ocfs2_control_send_down(const char *uuid, |
| 248 | int nodenum) |
| 249 | { |
| 250 | struct ocfs2_live_connection *c; |
| 251 | |
| 252 | mutex_lock(&ocfs2_control_lock); |
| 253 | |
| 254 | c = ocfs2_connection_find(uuid); |
| 255 | if (c) { |
| 256 | BUG_ON(c->oc_conn == NULL); |
| 257 | c->oc_conn->cc_recovery_handler(nodenum, |
| 258 | c->oc_conn->cc_recovery_data); |
| 259 | } |
| 260 | |
| 261 | mutex_unlock(&ocfs2_control_lock); |
| 262 | } |
| 263 | |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 264 | /* |
| 265 | * Called whenever configuration elements are sent to /dev/ocfs2_control. |
| 266 | * If all configuration elements are present, try to set the global |
| 267 | * values. If not, return -EAGAIN. If there is a problem, return a |
| 268 | * different error. |
| 269 | */ |
| 270 | static int ocfs2_control_install_private(struct file *file) |
Joel Becker | de870ef | 2008-02-18 17:07:09 -0800 | [diff] [blame] | 271 | { |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 272 | int rc = 0; |
| 273 | int set_p = 1; |
| 274 | struct ocfs2_control_private *p = file->private_data; |
| 275 | |
| 276 | BUG_ON(p->op_state != OCFS2_CONTROL_HANDSHAKE_PROTOCOL); |
| 277 | |
| 278 | if (p->op_this_node < 0) |
| 279 | set_p = 0; |
| 280 | |
| 281 | mutex_lock(&ocfs2_control_lock); |
| 282 | if (ocfs2_control_this_node < 0) { |
| 283 | if (set_p) |
| 284 | ocfs2_control_this_node = p->op_this_node; |
| 285 | } else if (ocfs2_control_this_node != p->op_this_node) |
| 286 | rc = -EINVAL; |
| 287 | mutex_unlock(&ocfs2_control_lock); |
| 288 | |
| 289 | if (!rc && set_p) { |
| 290 | /* We set the global values successfully */ |
| 291 | atomic_inc(&ocfs2_control_opened); |
| 292 | ocfs2_control_set_handshake_state(file, |
| 293 | OCFS2_CONTROL_HANDSHAKE_VALID); |
| 294 | } |
| 295 | |
| 296 | return rc; |
| 297 | } |
| 298 | |
| 299 | static int ocfs2_control_do_setnode_msg(struct file *file, |
| 300 | struct ocfs2_control_message_setn *msg) |
| 301 | { |
Joel Becker | de870ef | 2008-02-18 17:07:09 -0800 | [diff] [blame] | 302 | long nodenum; |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 303 | char *ptr = NULL; |
| 304 | struct ocfs2_control_private *p = file->private_data; |
Joel Becker | de870ef | 2008-02-18 17:07:09 -0800 | [diff] [blame] | 305 | |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 306 | if (ocfs2_control_get_handshake_state(file) != |
| 307 | OCFS2_CONTROL_HANDSHAKE_PROTOCOL) |
Joel Becker | de870ef | 2008-02-18 17:07:09 -0800 | [diff] [blame] | 308 | return -EINVAL; |
| 309 | |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 310 | if (strncmp(msg->tag, OCFS2_CONTROL_MESSAGE_SETNODE_OP, |
| 311 | OCFS2_CONTROL_MESSAGE_OP_LEN)) |
Joel Becker | de870ef | 2008-02-18 17:07:09 -0800 | [diff] [blame] | 312 | return -EINVAL; |
Joel Becker | de870ef | 2008-02-18 17:07:09 -0800 | [diff] [blame] | 313 | |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 314 | if ((msg->space != ' ') || (msg->newline != '\n')) |
| 315 | return -EINVAL; |
| 316 | msg->space = msg->newline = '\0'; |
| 317 | |
| 318 | nodenum = simple_strtol(msg->nodestr, &ptr, 16); |
| 319 | if (!ptr || *ptr) |
| 320 | return -EINVAL; |
| 321 | |
| 322 | if ((nodenum == LONG_MIN) || (nodenum == LONG_MAX) || |
| 323 | (nodenum > INT_MAX) || (nodenum < 0)) |
| 324 | return -ERANGE; |
| 325 | p->op_this_node = nodenum; |
| 326 | |
| 327 | return ocfs2_control_install_private(file); |
| 328 | } |
| 329 | |
| 330 | static int ocfs2_control_do_down_msg(struct file *file, |
| 331 | struct ocfs2_control_message_down *msg) |
| 332 | { |
| 333 | long nodenum; |
| 334 | char *p = NULL; |
| 335 | |
| 336 | if (ocfs2_control_get_handshake_state(file) != |
| 337 | OCFS2_CONTROL_HANDSHAKE_VALID) |
| 338 | return -EINVAL; |
| 339 | |
| 340 | if (strncmp(msg->tag, OCFS2_CONTROL_MESSAGE_DOWN_OP, |
| 341 | OCFS2_CONTROL_MESSAGE_OP_LEN)) |
| 342 | return -EINVAL; |
| 343 | |
| 344 | if ((msg->space1 != ' ') || (msg->space2 != ' ') || |
| 345 | (msg->newline != '\n')) |
| 346 | return -EINVAL; |
| 347 | msg->space1 = msg->space2 = msg->newline = '\0'; |
| 348 | |
| 349 | nodenum = simple_strtol(msg->nodestr, &p, 16); |
Joel Becker | de870ef | 2008-02-18 17:07:09 -0800 | [diff] [blame] | 350 | if (!p || *p) |
| 351 | return -EINVAL; |
| 352 | |
| 353 | if ((nodenum == LONG_MIN) || (nodenum == LONG_MAX) || |
| 354 | (nodenum > INT_MAX) || (nodenum < 0)) |
| 355 | return -ERANGE; |
| 356 | |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 357 | ocfs2_control_send_down(msg->uuid, nodenum); |
Joel Becker | de870ef | 2008-02-18 17:07:09 -0800 | [diff] [blame] | 358 | |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 359 | return 0; |
| 360 | } |
| 361 | |
| 362 | static ssize_t ocfs2_control_message(struct file *file, |
| 363 | const char __user *buf, |
| 364 | size_t count) |
| 365 | { |
| 366 | ssize_t ret; |
| 367 | union ocfs2_control_message msg; |
| 368 | |
| 369 | /* Try to catch padding issues */ |
| 370 | WARN_ON(offsetof(struct ocfs2_control_message_down, uuid) != |
| 371 | (sizeof(msg.u_down.tag) + sizeof(msg.u_down.space1))); |
| 372 | |
| 373 | memset(&msg, 0, sizeof(union ocfs2_control_message)); |
| 374 | ret = ocfs2_control_cfu(&msg, count, buf, count); |
| 375 | if (ret) |
| 376 | goto out; |
| 377 | |
| 378 | if ((count == OCFS2_CONTROL_MESSAGE_SETNODE_TOTAL_LEN) && |
| 379 | !strncmp(msg.tag, OCFS2_CONTROL_MESSAGE_SETNODE_OP, |
| 380 | OCFS2_CONTROL_MESSAGE_OP_LEN)) |
| 381 | ret = ocfs2_control_do_setnode_msg(file, &msg.u_setn); |
| 382 | else if ((count == OCFS2_CONTROL_MESSAGE_DOWN_TOTAL_LEN) && |
| 383 | !strncmp(msg.tag, OCFS2_CONTROL_MESSAGE_DOWN_OP, |
| 384 | OCFS2_CONTROL_MESSAGE_OP_LEN)) |
| 385 | ret = ocfs2_control_do_down_msg(file, &msg.u_down); |
| 386 | else |
| 387 | ret = -EINVAL; |
| 388 | |
| 389 | out: |
| 390 | return ret ? ret : count; |
Joel Becker | de870ef | 2008-02-18 17:07:09 -0800 | [diff] [blame] | 391 | } |
Joel Becker | 6427a72 | 2008-02-18 19:23:28 -0800 | [diff] [blame] | 392 | |
| 393 | static ssize_t ocfs2_control_write(struct file *file, |
| 394 | const char __user *buf, |
| 395 | size_t count, |
| 396 | loff_t *ppos) |
Joel Becker | 8adf053 | 2007-11-28 14:38:40 -0800 | [diff] [blame] | 397 | { |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 398 | ssize_t ret; |
| 399 | |
| 400 | switch (ocfs2_control_get_handshake_state(file)) { |
| 401 | case OCFS2_CONTROL_HANDSHAKE_INVALID: |
| 402 | ret = -EINVAL; |
| 403 | break; |
| 404 | |
| 405 | case OCFS2_CONTROL_HANDSHAKE_READ: |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 406 | ret = ocfs2_control_validate_protocol(file, buf, |
| 407 | count); |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 408 | break; |
| 409 | |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 410 | case OCFS2_CONTROL_HANDSHAKE_PROTOCOL: |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 411 | case OCFS2_CONTROL_HANDSHAKE_VALID: |
Joel Becker | de870ef | 2008-02-18 17:07:09 -0800 | [diff] [blame] | 412 | ret = ocfs2_control_message(file, buf, count); |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 413 | break; |
| 414 | |
| 415 | default: |
| 416 | BUG(); |
| 417 | ret = -EIO; |
| 418 | break; |
| 419 | } |
| 420 | |
| 421 | return ret; |
Joel Becker | 8adf053 | 2007-11-28 14:38:40 -0800 | [diff] [blame] | 422 | } |
| 423 | |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 424 | /* |
| 425 | * This is a naive version. If we ever have a new protocol, we'll expand |
| 426 | * it. Probably using seq_file. |
| 427 | */ |
Joel Becker | 6427a72 | 2008-02-18 19:23:28 -0800 | [diff] [blame] | 428 | static ssize_t ocfs2_control_read(struct file *file, |
| 429 | char __user *buf, |
| 430 | size_t count, |
| 431 | loff_t *ppos) |
| 432 | { |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 433 | char *proto_string = OCFS2_CONTROL_PROTO; |
| 434 | size_t to_write = 0; |
| 435 | |
| 436 | if (*ppos >= OCFS2_CONTROL_PROTO_LEN) |
| 437 | return 0; |
| 438 | |
| 439 | to_write = OCFS2_CONTROL_PROTO_LEN - *ppos; |
| 440 | if (to_write > count) |
| 441 | to_write = count; |
| 442 | if (copy_to_user(buf, proto_string + *ppos, to_write)) |
| 443 | return -EFAULT; |
| 444 | |
| 445 | *ppos += to_write; |
| 446 | |
| 447 | /* Have we read the whole protocol list? */ |
| 448 | if (*ppos >= OCFS2_CONTROL_PROTO_LEN) |
| 449 | ocfs2_control_set_handshake_state(file, |
| 450 | OCFS2_CONTROL_HANDSHAKE_READ); |
| 451 | |
| 452 | return to_write; |
Joel Becker | 6427a72 | 2008-02-18 19:23:28 -0800 | [diff] [blame] | 453 | } |
| 454 | |
| 455 | static int ocfs2_control_release(struct inode *inode, struct file *file) |
| 456 | { |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 457 | struct ocfs2_control_private *p = file->private_data; |
| 458 | |
| 459 | mutex_lock(&ocfs2_control_lock); |
| 460 | |
| 461 | if (ocfs2_control_get_handshake_state(file) != |
| 462 | OCFS2_CONTROL_HANDSHAKE_VALID) |
| 463 | goto out; |
| 464 | |
Joel Becker | 6427a72 | 2008-02-18 19:23:28 -0800 | [diff] [blame] | 465 | if (atomic_dec_and_test(&ocfs2_control_opened)) { |
Joel Becker | 6427a72 | 2008-02-18 19:23:28 -0800 | [diff] [blame] | 466 | if (!list_empty(&ocfs2_live_connection_list)) { |
| 467 | /* XXX: Do bad things! */ |
| 468 | printk(KERN_ERR |
| 469 | "ocfs2: Unexpected release of ocfs2_control!\n" |
| 470 | " Loss of cluster connection requires " |
| 471 | "an emergency restart!\n"); |
| 472 | emergency_restart(); |
| 473 | } |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 474 | /* Last valid close clears the node number */ |
| 475 | ocfs2_control_this_node = -1; |
Joel Becker | 6427a72 | 2008-02-18 19:23:28 -0800 | [diff] [blame] | 476 | } |
| 477 | |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 478 | out: |
| 479 | list_del_init(&p->op_list); |
| 480 | file->private_data = NULL; |
| 481 | |
| 482 | mutex_unlock(&ocfs2_control_lock); |
| 483 | |
| 484 | kfree(p); |
| 485 | |
Joel Becker | 6427a72 | 2008-02-18 19:23:28 -0800 | [diff] [blame] | 486 | return 0; |
| 487 | } |
| 488 | |
| 489 | static int ocfs2_control_open(struct inode *inode, struct file *file) |
| 490 | { |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 491 | struct ocfs2_control_private *p; |
| 492 | |
| 493 | p = kzalloc(sizeof(struct ocfs2_control_private), GFP_KERNEL); |
| 494 | if (!p) |
| 495 | return -ENOMEM; |
Joel Becker | 3cfd4ab | 2008-02-20 14:44:34 -0800 | [diff] [blame^] | 496 | p->op_this_node = -1; |
Joel Becker | 462c7e6 | 2008-02-18 19:40:12 -0800 | [diff] [blame] | 497 | |
| 498 | mutex_lock(&ocfs2_control_lock); |
| 499 | file->private_data = p; |
| 500 | list_add(&p->op_list, &ocfs2_control_private_list); |
| 501 | mutex_unlock(&ocfs2_control_lock); |
Joel Becker | 6427a72 | 2008-02-18 19:23:28 -0800 | [diff] [blame] | 502 | |
| 503 | return 0; |
| 504 | } |
| 505 | |
| 506 | static const struct file_operations ocfs2_control_fops = { |
| 507 | .open = ocfs2_control_open, |
| 508 | .release = ocfs2_control_release, |
| 509 | .read = ocfs2_control_read, |
| 510 | .write = ocfs2_control_write, |
| 511 | .owner = THIS_MODULE, |
| 512 | }; |
| 513 | |
| 514 | struct miscdevice ocfs2_control_device = { |
| 515 | .minor = MISC_DYNAMIC_MINOR, |
| 516 | .name = "ocfs2_control", |
| 517 | .fops = &ocfs2_control_fops, |
| 518 | }; |
| 519 | |
| 520 | static int ocfs2_control_init(void) |
| 521 | { |
| 522 | int rc; |
| 523 | |
| 524 | atomic_set(&ocfs2_control_opened, 0); |
| 525 | |
| 526 | rc = misc_register(&ocfs2_control_device); |
| 527 | if (rc) |
| 528 | printk(KERN_ERR |
| 529 | "ocfs2: Unable to register ocfs2_control device " |
| 530 | "(errno %d)\n", |
| 531 | -rc); |
| 532 | |
| 533 | return rc; |
| 534 | } |
| 535 | |
| 536 | static void ocfs2_control_exit(void) |
| 537 | { |
| 538 | int rc; |
| 539 | |
| 540 | rc = misc_deregister(&ocfs2_control_device); |
| 541 | if (rc) |
| 542 | printk(KERN_ERR |
| 543 | "ocfs2: Unable to deregister ocfs2_control device " |
| 544 | "(errno %d)\n", |
| 545 | -rc); |
| 546 | } |
| 547 | |
| 548 | static int __init user_stack_init(void) |
| 549 | { |
| 550 | return ocfs2_control_init(); |
| 551 | } |
| 552 | |
Joel Becker | 8adf053 | 2007-11-28 14:38:40 -0800 | [diff] [blame] | 553 | static void __exit user_stack_exit(void) |
| 554 | { |
Joel Becker | 6427a72 | 2008-02-18 19:23:28 -0800 | [diff] [blame] | 555 | ocfs2_control_exit(); |
Joel Becker | 8adf053 | 2007-11-28 14:38:40 -0800 | [diff] [blame] | 556 | } |
| 557 | |
| 558 | MODULE_AUTHOR("Oracle"); |
| 559 | MODULE_DESCRIPTION("ocfs2 driver for userspace cluster stacks"); |
| 560 | MODULE_LICENSE("GPL"); |
| 561 | module_init(user_stack_init); |
| 562 | module_exit(user_stack_exit); |