xen-vtx-unstable

annotate linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_xs.c @ 5867:c20ccb474166

Fix missing argument rename in xenbus_exists.
Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
author cl349@firebug.cl.cam.ac.uk
date Tue Jul 26 17:15:53 2005 +0000 (2005-07-26)
parents 42e8937a93f0
children 26e4e952c385
rev   line source
cl349@5598 1 /******************************************************************************
cl349@5598 2 * xenbus_xs.c
cl349@5598 3 *
cl349@5598 4 * This is the kernel equivalent of the "xs" library. We don't need everything
cl349@5863 5 * and we use xenbus_comms for communication.
cl349@5598 6 *
cl349@5598 7 * Copyright (C) 2005 Rusty Russell, IBM Corporation
cl349@5598 8 *
cl349@5598 9 * This file may be distributed separately from the Linux kernel, or
cl349@5598 10 * incorporated into other software packages, subject to the following license:
cl349@5598 11 *
cl349@5598 12 * Permission is hereby granted, free of charge, to any person obtaining a copy
cl349@5598 13 * of this source file (the "Software"), to deal in the Software without
cl349@5598 14 * restriction, including without limitation the rights to use, copy, modify,
cl349@5598 15 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
cl349@5598 16 * and to permit persons to whom the Software is furnished to do so, subject to
cl349@5598 17 * the following conditions:
cl349@5598 18 *
cl349@5598 19 * The above copyright notice and this permission notice shall be included in
cl349@5598 20 * all copies or substantial portions of the Software.
cl349@5598 21 *
cl349@5598 22 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
cl349@5598 23 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
cl349@5598 24 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
cl349@5598 25 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
cl349@5598 26 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
cl349@5598 27 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
cl349@5598 28 * IN THE SOFTWARE.
cl349@5598 29 */
cl349@5598 30
cl349@5598 31 #include <linux/errno.h>
cl349@5598 32 #include <linux/types.h>
cl349@5598 33 #include "xenstore/xenstored.h"
cl349@5598 34 #include <linux/uio.h>
cl349@5598 35 #include <linux/kernel.h>
cl349@5598 36 #include <linux/string.h>
cl349@5598 37 #include <linux/err.h>
cl349@5598 38 #include <linux/slab.h>
cl349@5598 39 #include <linux/fcntl.h>
cl349@5598 40 #include <linux/kthread.h>
cl349@5598 41 #include <asm-xen/xenbus.h>
cl349@5598 42 #include "xenbus_comms.h"
cl349@5598 43
cl349@5598 44 #define streq(a, b) (strcmp((a), (b)) == 0)
cl349@5598 45
cl349@5598 46 static void *xs_in, *xs_out;
cl349@5598 47 static LIST_HEAD(watches);
cl349@5863 48 DECLARE_MUTEX(xenbus_lock);
cl349@5598 49
cl349@5598 50 static int get_error(const char *errorstring)
cl349@5598 51 {
cl349@5598 52 unsigned int i;
cl349@5598 53
cl349@5598 54 for (i = 0; !streq(errorstring, xsd_errors[i].errstring); i++) {
cl349@5598 55 if (i == ARRAY_SIZE(xsd_errors) - 1) {
cl349@5670 56 printk(KERN_WARNING
cl349@5670 57 "XENBUS xen store gave: unknown error %s",
cl349@5598 58 errorstring);
cl349@5598 59 return EINVAL;
cl349@5598 60 }
cl349@5598 61 }
cl349@5598 62 return xsd_errors[i].errnum;
cl349@5598 63 }
cl349@5598 64
cl349@5598 65 static void *read_reply(enum xsd_sockmsg_type *type, unsigned int *len)
cl349@5598 66 {
cl349@5598 67 struct xsd_sockmsg msg;
cl349@5598 68 void *ret;
cl349@5598 69 int err;
cl349@5598 70
cl349@5598 71 err = xb_read(xs_in, &msg, sizeof(msg));
cl349@5598 72 if (err)
cl349@5598 73 return ERR_PTR(err);
cl349@5598 74
cl349@5598 75 ret = kmalloc(msg.len + 1, GFP_KERNEL);
cl349@5598 76 if (!ret)
cl349@5598 77 return ERR_PTR(-ENOMEM);
cl349@5598 78
cl349@5598 79 err = xb_read(xs_in, ret, msg.len);
cl349@5598 80 if (err) {
cl349@5598 81 kfree(ret);
cl349@5598 82 return ERR_PTR(err);
cl349@5598 83 }
cl349@5598 84 ((char*)ret)[msg.len] = '\0';
cl349@5598 85
cl349@5598 86 *type = msg.type;
cl349@5598 87 if (len)
cl349@5598 88 *len = msg.len;
cl349@5598 89 return ret;
cl349@5598 90 }
cl349@5598 91
cl349@5747 92 /* Emergency write. */
cl349@5863 93 void xenbus_debug_write(const char *str, unsigned int count)
cl349@5747 94 {
cl349@5747 95 struct xsd_sockmsg msg;
cl349@5747 96 void *out = (void *)xen_start_info.store_page;
cl349@5747 97
cl349@5747 98 msg.type = XS_DEBUG;
cl349@5747 99 msg.len = sizeof("print") + count + 1;
cl349@5747 100
cl349@5747 101 xb_write(out, &msg, sizeof(msg));
cl349@5747 102 xb_write(out, "print", sizeof("print"));
cl349@5747 103 xb_write(out, str, count);
cl349@5747 104 xb_write(out, "", 1);
cl349@5747 105 }
cl349@5747 106
cl349@5598 107 /* Send message to xs, get kmalloc'ed reply. ERR_PTR() on error. */
cl349@5598 108 static void *xs_talkv(enum xsd_sockmsg_type type,
cl349@5598 109 const struct kvec *iovec,
cl349@5598 110 unsigned int num_vecs,
cl349@5598 111 unsigned int *len)
cl349@5598 112 {
cl349@5598 113 struct xsd_sockmsg msg;
cl349@5598 114 void *ret = NULL;
cl349@5598 115 unsigned int i;
cl349@5598 116 int err;
cl349@5598 117
cl349@5863 118 WARN_ON(down_trylock(&xenbus_lock) == 0);
cl349@5598 119
cl349@5598 120 msg.type = type;
cl349@5598 121 msg.len = 0;
cl349@5598 122 for (i = 0; i < num_vecs; i++)
cl349@5598 123 msg.len += iovec[i].iov_len;
cl349@5598 124
cl349@5598 125 err = xb_write(xs_out, &msg, sizeof(msg));
cl349@5598 126 if (err)
cl349@5598 127 return ERR_PTR(err);
cl349@5598 128
cl349@5598 129 for (i = 0; i < num_vecs; i++) {
cl349@5598 130 err = xb_write(xs_out, iovec[i].iov_base, iovec[i].iov_len);;
cl349@5598 131 if (err)
cl349@5598 132 return ERR_PTR(err);
cl349@5598 133 }
cl349@5598 134
cl349@5598 135 /* Watches can have fired before reply comes: daemon detects
cl349@5598 136 * and re-transmits, so we can ignore this. */
cl349@5598 137 do {
cl349@5598 138 kfree(ret);
cl349@5598 139 ret = read_reply(&msg.type, len);
cl349@5598 140 if (IS_ERR(ret))
cl349@5598 141 return ret;
cl349@5598 142 } while (msg.type == XS_WATCH_EVENT);
cl349@5598 143
cl349@5598 144 if (msg.type == XS_ERROR) {
cl349@5598 145 err = get_error(ret);
cl349@5598 146 kfree(ret);
cl349@5598 147 return ERR_PTR(-err);
cl349@5598 148 }
cl349@5598 149
cl349@5598 150 BUG_ON(msg.type != type);
cl349@5598 151 return ret;
cl349@5598 152 }
cl349@5598 153
cl349@5598 154 /* Simplified version of xs_talkv: single message. */
cl349@5598 155 static void *xs_single(enum xsd_sockmsg_type type,
cl349@5598 156 const char *string, unsigned int *len)
cl349@5598 157 {
cl349@5598 158 struct kvec iovec;
cl349@5598 159
cl349@5598 160 iovec.iov_base = (void *)string;
cl349@5598 161 iovec.iov_len = strlen(string) + 1;
cl349@5598 162 return xs_talkv(type, &iovec, 1, len);
cl349@5598 163 }
cl349@5598 164
cl349@5598 165 /* Many commands only need an ack, don't care what it says. */
cl349@5598 166 static int xs_error(char *reply)
cl349@5598 167 {
cl349@5598 168 if (IS_ERR(reply))
cl349@5598 169 return PTR_ERR(reply);
cl349@5598 170 kfree(reply);
cl349@5598 171 return 0;
cl349@5598 172 }
cl349@5598 173
cl349@5598 174 static unsigned int count_strings(const char *strings, unsigned int len)
cl349@5598 175 {
cl349@5598 176 unsigned int num;
cl349@5598 177 const char *p;
cl349@5598 178
cl349@5598 179 for (p = strings, num = 0; p < strings + len; p += strlen(p) + 1)
cl349@5598 180 num++;
cl349@5598 181
cl349@5598 182 return num;
cl349@5598 183 }
cl349@5598 184
cl349@5863 185 /* Return the path to dir with /name appended. */
cl349@5863 186 static char *join(const char *dir, const char *name)
cl349@5863 187 {
cl349@5863 188 static char buffer[4096];
cl349@5863 189
cl349@5863 190 BUG_ON(down_trylock(&xenbus_lock) == 0);
cl349@5863 191 BUG_ON(strlen(dir) + strlen("/") + strlen(name) + 1 > sizeof(buffer));
cl349@5863 192
cl349@5863 193 strcpy(buffer, dir);
cl349@5863 194 if (!streq(name, "")) {
cl349@5863 195 strcat(buffer, "/");
cl349@5863 196 strcat(buffer, name);
cl349@5863 197 }
cl349@5863 198 return buffer;
cl349@5863 199 }
cl349@5863 200
cl349@5863 201 char **xenbus_directory(const char *dir, const char *node, unsigned int *num)
cl349@5598 202 {
cl349@5598 203 char *strings, *p, **ret;
cl349@5598 204 unsigned int len;
cl349@5598 205
cl349@5863 206 strings = xs_single(XS_DIRECTORY, join(dir, node), &len);
cl349@5598 207 if (IS_ERR(strings))
cl349@5598 208 return (char **)strings;
cl349@5598 209
cl349@5598 210 /* Count the strings. */
cl349@5598 211 *num = count_strings(strings, len);
cl349@5598 212
cl349@5598 213 /* Transfer to one big alloc for easy freeing. */
cl349@5598 214 ret = kmalloc(*num * sizeof(char *) + len, GFP_ATOMIC);
cl349@5598 215 if (!ret) {
cl349@5598 216 kfree(strings);
cl349@5598 217 return ERR_PTR(-ENOMEM);
cl349@5598 218 }
cl349@5598 219 memcpy(&ret[*num], strings, len);
cl349@5598 220 kfree(strings);
cl349@5598 221
cl349@5598 222 strings = (char *)&ret[*num];
cl349@5598 223 for (p = strings, *num = 0; p < strings + len; p += strlen(p) + 1)
cl349@5598 224 ret[(*num)++] = p;
cl349@5598 225 return ret;
cl349@5598 226 }
cl349@5598 227
cl349@5598 228 /* Check if a path exists. Return 1 if it does. */
cl349@5863 229 int xenbus_exists(const char *dir, const char *node)
cl349@5598 230 {
cl349@5863 231 char **d;
cl349@5670 232 int dir_n;
cl349@5598 233
cl349@5867 234 d = xenbus_directory(dir, node, &dir_n);
cl349@5863 235 if (IS_ERR(d))
cl349@5670 236 return 0;
cl349@5863 237 kfree(d);
cl349@5670 238 return 1;
cl349@5598 239 }
cl349@5598 240
cl349@5598 241 /* Get the value of a single file.
cl349@5598 242 * Returns a kmalloced value: call free() on it after use.
cl349@5598 243 * len indicates length in bytes.
cl349@5598 244 */
cl349@5863 245 void *xenbus_read(const char *dir, const char *node, unsigned int *len)
cl349@5598 246 {
cl349@5863 247 return xs_single(XS_READ, join(dir, node), len);
cl349@5598 248 }
cl349@5598 249
cl349@5598 250 /* Write the value of a single file.
cl349@5598 251 * Returns -err on failure. createflags can be 0, O_CREAT, or O_CREAT|O_EXCL.
cl349@5598 252 */
cl349@5863 253 int xenbus_write(const char *dir, const char *node,
cl349@5863 254 const char *string, int createflags)
cl349@5598 255 {
cl349@5863 256 const char *flags, *path;
cl349@5598 257 struct kvec iovec[3];
cl349@5598 258
cl349@5863 259 path = join(dir, node);
cl349@5598 260 /* Format: Flags (as string), path, data. */
cl349@5598 261 if (createflags == 0)
cl349@5598 262 flags = XS_WRITE_NONE;
cl349@5598 263 else if (createflags == O_CREAT)
cl349@5598 264 flags = XS_WRITE_CREATE;
cl349@5598 265 else if (createflags == (O_CREAT|O_EXCL))
cl349@5598 266 flags = XS_WRITE_CREATE_EXCL;
cl349@5598 267 else
cl349@5598 268 return -EINVAL;
cl349@5598 269
cl349@5598 270 iovec[0].iov_base = (void *)path;
cl349@5598 271 iovec[0].iov_len = strlen(path) + 1;
cl349@5598 272 iovec[1].iov_base = (void *)flags;
cl349@5598 273 iovec[1].iov_len = strlen(flags) + 1;
cl349@5863 274 iovec[2].iov_base = (void *)string;
cl349@5863 275 iovec[2].iov_len = strlen(string);
cl349@5598 276
cl349@5598 277 return xs_error(xs_talkv(XS_WRITE, iovec, ARRAY_SIZE(iovec), NULL));
cl349@5598 278 }
cl349@5598 279
cl349@5598 280 /* Create a new directory. */
cl349@5863 281 int xenbus_mkdir(const char *dir, const char *node)
cl349@5598 282 {
cl349@5863 283 return xs_error(xs_single(XS_MKDIR, join(dir, node), NULL));
cl349@5598 284 }
cl349@5598 285
cl349@5598 286 /* Destroy a file or directory (directories must be empty). */
cl349@5863 287 int xenbus_rm(const char *dir, const char *node)
cl349@5598 288 {
cl349@5863 289 return xs_error(xs_single(XS_RM, join(dir, node), NULL));
cl349@5598 290 }
cl349@5598 291
cl349@5598 292 /* Start a transaction: changes by others will not be seen during this
cl349@5598 293 * transaction, and changes will not be visible to others until end.
cl349@5598 294 * Transaction only applies to the given subtree.
cl349@5598 295 * You can only have one transaction at any time.
cl349@5598 296 */
cl349@5863 297 int xenbus_transaction_start(const char *subtree)
cl349@5598 298 {
cl349@5598 299 return xs_error(xs_single(XS_TRANSACTION_START, subtree, NULL));
cl349@5598 300 }
cl349@5598 301
cl349@5598 302 /* End a transaction.
cl349@5598 303 * If abandon is true, transaction is discarded instead of committed.
cl349@5598 304 */
cl349@5863 305 int xenbus_transaction_end(int abort)
cl349@5598 306 {
cl349@5598 307 char abortstr[2];
cl349@5598 308
cl349@5598 309 if (abort)
cl349@5598 310 strcpy(abortstr, "F");
cl349@5598 311 else
cl349@5598 312 strcpy(abortstr, "T");
cl349@5598 313 return xs_error(xs_single(XS_TRANSACTION_END, abortstr, NULL));
cl349@5598 314 }
cl349@5598 315
cl349@5863 316 /* Single read and scanf: returns -errno or num scanned. */
cl349@5863 317 int xenbus_scanf(const char *dir, const char *node, const char *fmt, ...)
cl349@5863 318 {
cl349@5863 319 va_list ap;
cl349@5863 320 int ret;
cl349@5863 321 char *val;
cl349@5863 322
cl349@5863 323 val = xenbus_read(dir, node, NULL);
cl349@5863 324 if (IS_ERR(val))
cl349@5863 325 return PTR_ERR(val);
cl349@5863 326
cl349@5863 327 va_start(ap, fmt);
cl349@5863 328 ret = vsscanf(val, fmt, ap);
cl349@5863 329 va_end(ap);
cl349@5863 330 kfree(val);
cl349@5863 331 /* Distinctive errno. */
cl349@5863 332 if (ret == 0)
cl349@5863 333 return -ERANGE;
cl349@5863 334 return ret;
cl349@5863 335 }
cl349@5863 336
cl349@5863 337 /* Single printf and write: returns -errno or 0. */
cl349@5863 338 int xenbus_printf(const char *dir, const char *node, const char *fmt, ...)
cl349@5598 339 {
cl349@5863 340 va_list ap;
cl349@5863 341 int ret;
cl349@5863 342 static char buffer[4096];
cl349@5863 343
cl349@5863 344 BUG_ON(down_trylock(&xenbus_lock) == 0);
cl349@5863 345 va_start(ap, fmt);
cl349@5863 346 ret = vsnprintf(buffer, sizeof(buffer), fmt, ap);
cl349@5863 347 va_end(ap);
cl349@5863 348
cl349@5863 349 BUG_ON(ret > sizeof(buffer)-1);
cl349@5864 350 return xenbus_write(dir, node, buffer, O_CREAT);
cl349@5863 351 }
cl349@5598 352
cl349@5863 353 /* Takes tuples of names, scanf-style args, and void **, NULL terminated. */
cl349@5863 354 int xenbus_gather(const char *dir, ...)
cl349@5863 355 {
cl349@5863 356 va_list ap;
cl349@5863 357 const char *name;
cl349@5863 358 int ret = 0;
cl349@5863 359
cl349@5863 360 va_start(ap, dir);
cl349@5863 361 while (ret == 0 && (name = va_arg(ap, char *)) != NULL) {
cl349@5863 362 const char *fmt = va_arg(ap, char *);
cl349@5863 363 void *result = va_arg(ap, void *);
cl349@5863 364 char *p;
cl349@5863 365
cl349@5863 366 p = xenbus_read(dir, name, NULL);
cl349@5863 367 if (IS_ERR(p)) {
cl349@5863 368 ret = PTR_ERR(p);
cl349@5863 369 break;
cl349@5863 370 }
cl349@5863 371 if (sscanf(p, fmt, result) == 0)
cl349@5863 372 ret = -EINVAL;
cl349@5863 373 kfree(p);
cl349@5863 374 }
cl349@5863 375 va_end(ap);
cl349@5863 376 return ret;
cl349@5598 377 }
cl349@5598 378
cl349@5598 379 static int xs_watch(const char *path, const char *token, unsigned int priority)
cl349@5598 380 {
cl349@5598 381 char prio[32];
cl349@5598 382 struct kvec iov[3];
cl349@5598 383
cl349@5598 384 sprintf(prio, "%u", priority);
cl349@5598 385 iov[0].iov_base = (void *)path;
cl349@5598 386 iov[0].iov_len = strlen(path) + 1;
cl349@5598 387 iov[1].iov_base = (void *)token;
cl349@5598 388 iov[1].iov_len = strlen(token) + 1;
cl349@5598 389 iov[2].iov_base = prio;
cl349@5598 390 iov[2].iov_len = strlen(prio) + 1;
cl349@5598 391
cl349@5598 392 return xs_error(xs_talkv(XS_WATCH, iov, ARRAY_SIZE(iov), NULL));
cl349@5598 393 }
cl349@5598 394
cl349@5598 395 static char *xs_read_watch(char **token)
cl349@5598 396 {
cl349@5598 397 enum xsd_sockmsg_type type;
cl349@5598 398 char *ret;
cl349@5598 399
cl349@5598 400 ret = read_reply(&type, NULL);
cl349@5598 401 if (IS_ERR(ret))
cl349@5598 402 return ret;
cl349@5598 403
cl349@5598 404 BUG_ON(type != XS_WATCH_EVENT);
cl349@5598 405 *token = ret + strlen(ret) + 1;
cl349@5598 406 return ret;
cl349@5598 407 }
cl349@5598 408
cl349@5598 409 static int xs_acknowledge_watch(const char *token)
cl349@5598 410 {
cl349@5598 411 return xs_error(xs_single(XS_WATCH_ACK, token, NULL));
cl349@5598 412 }
cl349@5598 413
cl349@5598 414 static int xs_unwatch(const char *path, const char *token)
cl349@5598 415 {
cl349@5598 416 struct kvec iov[2];
cl349@5598 417
cl349@5598 418 iov[0].iov_base = (char *)path;
cl349@5598 419 iov[0].iov_len = strlen(path) + 1;
cl349@5598 420 iov[1].iov_base = (char *)token;
cl349@5598 421 iov[1].iov_len = strlen(token) + 1;
cl349@5598 422
cl349@5598 423 return xs_error(xs_talkv(XS_UNWATCH, iov, ARRAY_SIZE(iov), NULL));
cl349@5598 424 }
cl349@5598 425
cl349@5598 426 /* A little paranoia: we don't just trust token. */
cl349@5598 427 static struct xenbus_watch *find_watch(const char *token)
cl349@5598 428 {
cl349@5598 429 struct xenbus_watch *i, *cmp;
cl349@5598 430
cl349@5598 431 cmp = (void *)simple_strtoul(token, NULL, 16);
cl349@5598 432
cl349@5598 433 list_for_each_entry(i, &watches, list)
cl349@5598 434 if (i == cmp)
cl349@5598 435 return i;
cl349@5598 436 return NULL;
cl349@5598 437 }
cl349@5598 438
cl349@5598 439 /* Register callback to watch this node. */
cl349@5598 440 int register_xenbus_watch(struct xenbus_watch *watch)
cl349@5598 441 {
cl349@5598 442 /* Pointer in ascii is the token. */
cl349@5598 443 char token[sizeof(watch) * 2 + 1];
cl349@5598 444 int err;
cl349@5598 445
cl349@5598 446 sprintf(token, "%lX", (long)watch);
cl349@5598 447 BUG_ON(find_watch(token));
cl349@5598 448
cl349@5598 449 err = xs_watch(watch->node, token, watch->priority);
cl349@5598 450 if (!err)
cl349@5598 451 list_add(&watch->list, &watches);
cl349@5598 452 return err;
cl349@5598 453 }
cl349@5598 454
cl349@5598 455 void unregister_xenbus_watch(struct xenbus_watch *watch)
cl349@5598 456 {
cl349@5598 457 char token[sizeof(watch) * 2 + 1];
cl349@5598 458 int err;
cl349@5598 459
cl349@5598 460 sprintf(token, "%lX", (long)watch);
cl349@5598 461 BUG_ON(!find_watch(token));
cl349@5598 462
cl349@5598 463 err = xs_unwatch(watch->node, token);
cl349@5598 464 list_del(&watch->list);
cl349@5598 465
cl349@5598 466 if (err)
cl349@5598 467 printk(KERN_WARNING "XENBUS Failed to release watch %s: %i\n",
cl349@5598 468 watch->node, err);
cl349@5598 469 }
cl349@5598 470
cl349@5598 471 static int watch_thread(void *unused)
cl349@5598 472 {
cl349@5598 473 for (;;) {
cl349@5598 474 char *token;
cl349@5598 475 char *node = NULL;
cl349@5598 476
cl349@5598 477 wait_event(xb_waitq, xs_input_avail(xs_in));
cl349@5598 478
cl349@5598 479 /* If this is a spurious wakeup caused by someone
cl349@5598 480 * doing an op, they'll hold the lock and the buffer
cl349@5598 481 * will be empty by the time we get there.
cl349@5598 482 */
cl349@5863 483 down(&xenbus_lock);
cl349@5598 484 if (xs_input_avail(xs_in))
cl349@5598 485 node = xs_read_watch(&token);
cl349@5747 486
cl349@5598 487 if (node && !IS_ERR(node)) {
cl349@5598 488 struct xenbus_watch *w;
cl349@5598 489 int err;
cl349@5598 490
cl349@5598 491 w = find_watch(token);
cl349@5598 492 BUG_ON(!w);
cl349@5598 493 w->callback(w, node);
cl349@5747 494 /* FIXME: Only ack if it wasn't deleted. */
cl349@5598 495 err = xs_acknowledge_watch(token);
cl349@5598 496 if (err)
cl349@5598 497 printk(KERN_WARNING
cl349@5598 498 "XENBUS acknowledge %s failed %i\n",
cl349@5598 499 node, err);
cl349@5598 500 kfree(node);
cl349@5598 501 } else
cl349@5598 502 printk(KERN_WARNING "XENBUS xs_read_watch: %li\n",
cl349@5598 503 PTR_ERR(node));
cl349@5863 504 up(&xenbus_lock);
cl349@5598 505 }
cl349@5598 506 }
cl349@5598 507
cl349@5598 508 int xs_init(void)
cl349@5598 509 {
cl349@5598 510 int err;
cl349@5598 511 struct task_struct *watcher;
cl349@5598 512
cl349@5598 513 err = xb_init_comms(&xs_in, &xs_out);
cl349@5598 514 if (err)
cl349@5598 515 return err;
cl349@5598 516
cl349@5598 517 watcher = kthread_run(watch_thread, NULL, "kxbwatch");
cl349@5598 518 if (IS_ERR(watcher))
cl349@5598 519 return PTR_ERR(watcher);
cl349@5598 520 return 0;
cl349@5598 521 }