1 /* 2 * QEMU System Emulator block driver 3 * 4 * Copyright (c) 2011 IBM Corp. 5 * Copyright (c) 2012 Red Hat, Inc. 6 * 7 * Permission is hereby granted, free of charge, to any person obtaining a copy 8 * of this software and associated documentation files (the "Software"), to deal 9 * in the Software without restriction, including without limitation the rights 10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 11 * copies of the Software, and to permit persons to whom the Software is 12 * furnished to do so, subject to the following conditions: 13 * 14 * The above copyright notice and this permission notice shall be included in 15 * all copies or substantial portions of the Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 23 * THE SOFTWARE. 24 */ 25 26 #include "qemu/osdep.h" 27 #include "block/block.h" 28 #include "block/blockjob_int.h" 29 #include "block/block_int.h" 30 #include "block/trace.h" 31 #include "sysemu/block-backend.h" 32 #include "qapi/error.h" 33 #include "qapi/qapi-events-block-core.h" 34 #include "qapi/qmp/qerror.h" 35 #include "qemu/coroutine.h" 36 #include "qemu/main-loop.h" 37 #include "qemu/timer.h" 38 39 /* 40 * The block job API is composed of two categories of functions. 41 * 42 * The first includes functions used by the monitor. The monitor is 43 * peculiar in that it accesses the block job list with block_job_get, and 44 * therefore needs consistency across block_job_get and the actual operation 45 * (e.g. block_job_set_speed). The consistency is achieved with 46 * aio_context_acquire/release. These functions are declared in blockjob.h. 47 * 48 * The second includes functions used by the block job drivers and sometimes 49 * by the core block layer. These do not care about locking, because the 50 * whole coroutine runs under the AioContext lock, and are declared in 51 * blockjob_int.h. 52 */ 53 54 static bool is_block_job(Job *job) 55 { 56 return job_type(job) == JOB_TYPE_BACKUP || 57 job_type(job) == JOB_TYPE_COMMIT || 58 job_type(job) == JOB_TYPE_MIRROR || 59 job_type(job) == JOB_TYPE_STREAM; 60 } 61 62 BlockJob *block_job_next(BlockJob *bjob) 63 { 64 Job *job = bjob ? &bjob->job : NULL; 65 66 do { 67 job = job_next(job); 68 } while (job && !is_block_job(job)); 69 70 return job ? container_of(job, BlockJob, job) : NULL; 71 } 72 73 BlockJob *block_job_get(const char *id) 74 { 75 Job *job = job_get(id); 76 77 if (job && is_block_job(job)) { 78 return container_of(job, BlockJob, job); 79 } else { 80 return NULL; 81 } 82 } 83 84 void block_job_free(Job *job) 85 { 86 BlockJob *bjob = container_of(job, BlockJob, job); 87 88 block_job_remove_all_bdrv(bjob); 89 blk_unref(bjob->blk); 90 error_free(bjob->blocker); 91 } 92 93 static char *child_job_get_parent_desc(BdrvChild *c) 94 { 95 BlockJob *job = c->opaque; 96 return g_strdup_printf("%s job '%s'", job_type_str(&job->job), job->job.id); 97 } 98 99 static void child_job_drained_begin(BdrvChild *c) 100 { 101 BlockJob *job = c->opaque; 102 job_pause(&job->job); 103 } 104 105 static bool child_job_drained_poll(BdrvChild *c) 106 { 107 BlockJob *bjob = c->opaque; 108 Job *job = &bjob->job; 109 const BlockJobDriver *drv = block_job_driver(bjob); 110 111 /* An inactive or completed job doesn't have any pending requests. Jobs 112 * with !job->busy are either already paused or have a pause point after 113 * being reentered, so no job driver code will run before they pause. */ 114 if (!job->busy || job_is_completed(job)) { 115 return false; 116 } 117 118 /* Otherwise, assume that it isn't fully stopped yet, but allow the job to 119 * override this assumption. */ 120 if (drv->drained_poll) { 121 return drv->drained_poll(bjob); 122 } else { 123 return true; 124 } 125 } 126 127 static void child_job_drained_end(BdrvChild *c, int *drained_end_counter) 128 { 129 BlockJob *job = c->opaque; 130 job_resume(&job->job); 131 } 132 133 static bool child_job_can_set_aio_ctx(BdrvChild *c, AioContext *ctx, 134 GSList **ignore, Error **errp) 135 { 136 BlockJob *job = c->opaque; 137 GSList *l; 138 139 for (l = job->nodes; l; l = l->next) { 140 BdrvChild *sibling = l->data; 141 if (!bdrv_child_can_set_aio_context(sibling, ctx, ignore, errp)) { 142 return false; 143 } 144 } 145 return true; 146 } 147 148 static void child_job_set_aio_ctx(BdrvChild *c, AioContext *ctx, 149 GSList **ignore) 150 { 151 BlockJob *job = c->opaque; 152 GSList *l; 153 154 for (l = job->nodes; l; l = l->next) { 155 BdrvChild *sibling = l->data; 156 if (g_slist_find(*ignore, sibling)) { 157 continue; 158 } 159 *ignore = g_slist_prepend(*ignore, sibling); 160 bdrv_set_aio_context_ignore(sibling->bs, ctx, ignore); 161 } 162 163 job->job.aio_context = ctx; 164 } 165 166 static const BdrvChildClass child_job = { 167 .get_parent_desc = child_job_get_parent_desc, 168 .drained_begin = child_job_drained_begin, 169 .drained_poll = child_job_drained_poll, 170 .drained_end = child_job_drained_end, 171 .can_set_aio_ctx = child_job_can_set_aio_ctx, 172 .set_aio_ctx = child_job_set_aio_ctx, 173 .stay_at_node = true, 174 }; 175 176 void block_job_remove_all_bdrv(BlockJob *job) 177 { 178 /* 179 * bdrv_root_unref_child() may reach child_job_[can_]set_aio_ctx(), 180 * which will also traverse job->nodes, so consume the list one by 181 * one to make sure that such a concurrent access does not attempt 182 * to process an already freed BdrvChild. 183 */ 184 while (job->nodes) { 185 GSList *l = job->nodes; 186 BdrvChild *c = l->data; 187 188 job->nodes = l->next; 189 190 bdrv_op_unblock_all(c->bs, job->blocker); 191 bdrv_root_unref_child(c); 192 193 g_slist_free_1(l); 194 } 195 } 196 197 bool block_job_has_bdrv(BlockJob *job, BlockDriverState *bs) 198 { 199 GSList *el; 200 201 for (el = job->nodes; el; el = el->next) { 202 BdrvChild *c = el->data; 203 if (c->bs == bs) { 204 return true; 205 } 206 } 207 208 return false; 209 } 210 211 int block_job_add_bdrv(BlockJob *job, const char *name, BlockDriverState *bs, 212 uint64_t perm, uint64_t shared_perm, Error **errp) 213 { 214 BdrvChild *c; 215 216 bdrv_ref(bs); 217 if (job->job.aio_context != qemu_get_aio_context()) { 218 aio_context_release(job->job.aio_context); 219 } 220 c = bdrv_root_attach_child(bs, name, &child_job, 0, 221 job->job.aio_context, perm, shared_perm, job, 222 errp); 223 if (job->job.aio_context != qemu_get_aio_context()) { 224 aio_context_acquire(job->job.aio_context); 225 } 226 if (c == NULL) { 227 return -EPERM; 228 } 229 230 job->nodes = g_slist_prepend(job->nodes, c); 231 bdrv_op_block_all(bs, job->blocker); 232 233 return 0; 234 } 235 236 static void block_job_on_idle(Notifier *n, void *opaque) 237 { 238 aio_wait_kick(); 239 } 240 241 bool block_job_is_internal(BlockJob *job) 242 { 243 return (job->job.id == NULL); 244 } 245 246 const BlockJobDriver *block_job_driver(BlockJob *job) 247 { 248 return container_of(job->job.driver, BlockJobDriver, job_driver); 249 } 250 251 /* Assumes the job_mutex is held */ 252 static bool job_timer_pending(Job *job) 253 { 254 return timer_pending(&job->sleep_timer); 255 } 256 257 void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp) 258 { 259 const BlockJobDriver *drv = block_job_driver(job); 260 int64_t old_speed = job->speed; 261 262 if (job_apply_verb(&job->job, JOB_VERB_SET_SPEED, errp)) { 263 return; 264 } 265 if (speed < 0) { 266 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "speed", 267 "a non-negative value"); 268 return; 269 } 270 271 ratelimit_set_speed(&job->limit, speed, BLOCK_JOB_SLICE_TIME); 272 273 job->speed = speed; 274 275 if (drv->set_speed) { 276 drv->set_speed(job, speed); 277 } 278 279 if (speed && speed <= old_speed) { 280 return; 281 } 282 283 /* kick only if a timer is pending */ 284 job_enter_cond(&job->job, job_timer_pending); 285 } 286 287 int64_t block_job_ratelimit_get_delay(BlockJob *job, uint64_t n) 288 { 289 if (!job->speed) { 290 return 0; 291 } 292 293 return ratelimit_calculate_delay(&job->limit, n); 294 } 295 296 BlockJobInfo *block_job_query(BlockJob *job, Error **errp) 297 { 298 BlockJobInfo *info; 299 300 if (block_job_is_internal(job)) { 301 error_setg(errp, "Cannot query QEMU internal jobs"); 302 return NULL; 303 } 304 info = g_new0(BlockJobInfo, 1); 305 info->type = g_strdup(job_type_str(&job->job)); 306 info->device = g_strdup(job->job.id); 307 info->busy = qatomic_read(&job->job.busy); 308 info->paused = job->job.pause_count > 0; 309 info->offset = job->job.progress.current; 310 info->len = job->job.progress.total; 311 info->speed = job->speed; 312 info->io_status = job->iostatus; 313 info->ready = job_is_ready(&job->job), 314 info->status = job->job.status; 315 info->auto_finalize = job->job.auto_finalize; 316 info->auto_dismiss = job->job.auto_dismiss; 317 info->has_error = job->job.ret != 0; 318 info->error = job->job.ret ? g_strdup(strerror(-job->job.ret)) : NULL; 319 return info; 320 } 321 322 static void block_job_iostatus_set_err(BlockJob *job, int error) 323 { 324 if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) { 325 job->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE : 326 BLOCK_DEVICE_IO_STATUS_FAILED; 327 } 328 } 329 330 static void block_job_event_cancelled(Notifier *n, void *opaque) 331 { 332 BlockJob *job = opaque; 333 334 if (block_job_is_internal(job)) { 335 return; 336 } 337 338 qapi_event_send_block_job_cancelled(job_type(&job->job), 339 job->job.id, 340 job->job.progress.total, 341 job->job.progress.current, 342 job->speed); 343 } 344 345 static void block_job_event_completed(Notifier *n, void *opaque) 346 { 347 BlockJob *job = opaque; 348 const char *msg = NULL; 349 350 if (block_job_is_internal(job)) { 351 return; 352 } 353 354 if (job->job.ret < 0) { 355 msg = strerror(-job->job.ret); 356 } 357 358 qapi_event_send_block_job_completed(job_type(&job->job), 359 job->job.id, 360 job->job.progress.total, 361 job->job.progress.current, 362 job->speed, 363 !!msg, 364 msg); 365 } 366 367 static void block_job_event_pending(Notifier *n, void *opaque) 368 { 369 BlockJob *job = opaque; 370 371 if (block_job_is_internal(job)) { 372 return; 373 } 374 375 qapi_event_send_block_job_pending(job_type(&job->job), 376 job->job.id); 377 } 378 379 static void block_job_event_ready(Notifier *n, void *opaque) 380 { 381 BlockJob *job = opaque; 382 383 if (block_job_is_internal(job)) { 384 return; 385 } 386 387 qapi_event_send_block_job_ready(job_type(&job->job), 388 job->job.id, 389 job->job.progress.total, 390 job->job.progress.current, 391 job->speed); 392 } 393 394 395 /* 396 * API for block job drivers and the block layer. These functions are 397 * declared in blockjob_int.h. 398 */ 399 400 void *block_job_create(const char *job_id, const BlockJobDriver *driver, 401 JobTxn *txn, BlockDriverState *bs, uint64_t perm, 402 uint64_t shared_perm, int64_t speed, int flags, 403 BlockCompletionFunc *cb, void *opaque, Error **errp) 404 { 405 BlockBackend *blk; 406 BlockJob *job; 407 408 if (job_id == NULL && !(flags & JOB_INTERNAL)) { 409 job_id = bdrv_get_device_name(bs); 410 } 411 412 blk = blk_new_with_bs(bs, perm, shared_perm, errp); 413 if (!blk) { 414 return NULL; 415 } 416 417 job = job_create(job_id, &driver->job_driver, txn, blk_get_aio_context(blk), 418 flags, cb, opaque, errp); 419 if (job == NULL) { 420 blk_unref(blk); 421 return NULL; 422 } 423 424 assert(is_block_job(&job->job)); 425 assert(job->job.driver->free == &block_job_free); 426 assert(job->job.driver->user_resume == &block_job_user_resume); 427 428 job->blk = blk; 429 430 job->finalize_cancelled_notifier.notify = block_job_event_cancelled; 431 job->finalize_completed_notifier.notify = block_job_event_completed; 432 job->pending_notifier.notify = block_job_event_pending; 433 job->ready_notifier.notify = block_job_event_ready; 434 job->idle_notifier.notify = block_job_on_idle; 435 436 notifier_list_add(&job->job.on_finalize_cancelled, 437 &job->finalize_cancelled_notifier); 438 notifier_list_add(&job->job.on_finalize_completed, 439 &job->finalize_completed_notifier); 440 notifier_list_add(&job->job.on_pending, &job->pending_notifier); 441 notifier_list_add(&job->job.on_ready, &job->ready_notifier); 442 notifier_list_add(&job->job.on_idle, &job->idle_notifier); 443 444 error_setg(&job->blocker, "block device is in use by block job: %s", 445 job_type_str(&job->job)); 446 block_job_add_bdrv(job, "main node", bs, 0, BLK_PERM_ALL, &error_abort); 447 448 bdrv_op_unblock(bs, BLOCK_OP_TYPE_DATAPLANE, job->blocker); 449 450 /* Disable request queuing in the BlockBackend to avoid deadlocks on drain: 451 * The job reports that it's busy until it reaches a pause point. */ 452 blk_set_disable_request_queuing(blk, true); 453 blk_set_allow_aio_context_change(blk, true); 454 455 /* Only set speed when necessary to avoid NotSupported error */ 456 if (speed != 0) { 457 Error *local_err = NULL; 458 459 block_job_set_speed(job, speed, &local_err); 460 if (local_err) { 461 job_early_fail(&job->job); 462 error_propagate(errp, local_err); 463 return NULL; 464 } 465 } 466 467 return job; 468 } 469 470 void block_job_iostatus_reset(BlockJob *job) 471 { 472 if (job->iostatus == BLOCK_DEVICE_IO_STATUS_OK) { 473 return; 474 } 475 assert(job->job.user_paused && job->job.pause_count > 0); 476 job->iostatus = BLOCK_DEVICE_IO_STATUS_OK; 477 } 478 479 void block_job_user_resume(Job *job) 480 { 481 BlockJob *bjob = container_of(job, BlockJob, job); 482 block_job_iostatus_reset(bjob); 483 } 484 485 BlockErrorAction block_job_error_action(BlockJob *job, BlockdevOnError on_err, 486 int is_read, int error) 487 { 488 BlockErrorAction action; 489 490 switch (on_err) { 491 case BLOCKDEV_ON_ERROR_ENOSPC: 492 case BLOCKDEV_ON_ERROR_AUTO: 493 action = (error == ENOSPC) ? 494 BLOCK_ERROR_ACTION_STOP : BLOCK_ERROR_ACTION_REPORT; 495 break; 496 case BLOCKDEV_ON_ERROR_STOP: 497 action = BLOCK_ERROR_ACTION_STOP; 498 break; 499 case BLOCKDEV_ON_ERROR_REPORT: 500 action = BLOCK_ERROR_ACTION_REPORT; 501 break; 502 case BLOCKDEV_ON_ERROR_IGNORE: 503 action = BLOCK_ERROR_ACTION_IGNORE; 504 break; 505 default: 506 abort(); 507 } 508 if (!block_job_is_internal(job)) { 509 qapi_event_send_block_job_error(job->job.id, 510 is_read ? IO_OPERATION_TYPE_READ : 511 IO_OPERATION_TYPE_WRITE, 512 action); 513 } 514 if (action == BLOCK_ERROR_ACTION_STOP) { 515 if (!job->job.user_paused) { 516 job_pause(&job->job); 517 /* make the pause user visible, which will be resumed from QMP. */ 518 job->job.user_paused = true; 519 } 520 block_job_iostatus_set_err(job, error); 521 } 522 return action; 523 } 524