1 | /* |
2 | * QEMU Block backends |
3 | * |
4 | * Copyright (C) 2014-2016 Red Hat, Inc. |
5 | * |
6 | * Authors: |
7 | * Markus Armbruster <armbru@redhat.com>, |
8 | * |
9 | * This work is licensed under the terms of the GNU LGPL, version 2.1 |
10 | * or later. See the COPYING.LIB file in the top-level directory. |
11 | */ |
12 | |
13 | #include "qemu/osdep.h" |
14 | #include "sysemu/block-backend.h" |
15 | #include "block/block_int.h" |
16 | #include "block/blockjob.h" |
17 | #include "block/throttle-groups.h" |
18 | #include "hw/qdev-core.h" |
19 | #include "sysemu/blockdev.h" |
20 | #include "sysemu/runstate.h" |
21 | #include "qapi/error.h" |
22 | #include "qapi/qapi-events-block.h" |
23 | #include "qemu/id.h" |
24 | #include "qemu/main-loop.h" |
25 | #include "qemu/option.h" |
26 | #include "trace.h" |
27 | #include "migration/misc.h" |
28 | |
29 | /* Number of coroutines to reserve per attached device model */ |
30 | #define COROUTINE_POOL_RESERVATION 64 |
31 | |
32 | #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */ |
33 | |
34 | static AioContext *blk_aiocb_get_aio_context(BlockAIOCB *acb); |
35 | |
36 | typedef struct BlockBackendAioNotifier { |
37 | void (*attached_aio_context)(AioContext *new_context, void *opaque); |
38 | void (*detach_aio_context)(void *opaque); |
39 | void *opaque; |
40 | QLIST_ENTRY(BlockBackendAioNotifier) list; |
41 | } BlockBackendAioNotifier; |
42 | |
43 | struct BlockBackend { |
44 | char *name; |
45 | int refcnt; |
46 | BdrvChild *root; |
47 | AioContext *ctx; |
48 | DriveInfo *legacy_dinfo; /* null unless created by drive_new() */ |
49 | QTAILQ_ENTRY(BlockBackend) link; /* for block_backends */ |
50 | QTAILQ_ENTRY(BlockBackend) monitor_link; /* for monitor_block_backends */ |
51 | BlockBackendPublic public; |
52 | |
53 | DeviceState *dev; /* attached device model, if any */ |
54 | const BlockDevOps *dev_ops; |
55 | void *dev_opaque; |
56 | |
57 | /* the block size for which the guest device expects atomicity */ |
58 | int guest_block_size; |
59 | |
60 | /* If the BDS tree is removed, some of its options are stored here (which |
61 | * can be used to restore those options in the new BDS on insert) */ |
62 | BlockBackendRootState root_state; |
63 | |
64 | bool enable_write_cache; |
65 | |
66 | /* I/O stats (display with "info blockstats"). */ |
67 | BlockAcctStats stats; |
68 | |
69 | BlockdevOnError on_read_error, on_write_error; |
70 | bool iostatus_enabled; |
71 | BlockDeviceIoStatus iostatus; |
72 | |
73 | uint64_t perm; |
74 | uint64_t shared_perm; |
75 | bool disable_perm; |
76 | |
77 | bool allow_aio_context_change; |
78 | bool allow_write_beyond_eof; |
79 | |
80 | NotifierList remove_bs_notifiers, insert_bs_notifiers; |
81 | QLIST_HEAD(, BlockBackendAioNotifier) aio_notifiers; |
82 | |
83 | int quiesce_counter; |
84 | CoQueue queued_requests; |
85 | bool disable_request_queuing; |
86 | |
87 | VMChangeStateEntry *vmsh; |
88 | bool force_allow_inactivate; |
89 | |
90 | /* Number of in-flight aio requests. BlockDriverState also counts |
91 | * in-flight requests but aio requests can exist even when blk->root is |
92 | * NULL, so we cannot rely on its counter for that case. |
93 | * Accessed with atomic ops. |
94 | */ |
95 | unsigned int in_flight; |
96 | }; |
97 | |
98 | typedef struct BlockBackendAIOCB { |
99 | BlockAIOCB common; |
100 | BlockBackend *blk; |
101 | int ret; |
102 | } BlockBackendAIOCB; |
103 | |
104 | static const AIOCBInfo block_backend_aiocb_info = { |
105 | .get_aio_context = blk_aiocb_get_aio_context, |
106 | .aiocb_size = sizeof(BlockBackendAIOCB), |
107 | }; |
108 | |
109 | static void drive_info_del(DriveInfo *dinfo); |
110 | static BlockBackend *bdrv_first_blk(BlockDriverState *bs); |
111 | |
112 | /* All BlockBackends */ |
113 | static QTAILQ_HEAD(, BlockBackend) block_backends = |
114 | QTAILQ_HEAD_INITIALIZER(block_backends); |
115 | |
116 | /* All BlockBackends referenced by the monitor and which are iterated through by |
117 | * blk_next() */ |
118 | static QTAILQ_HEAD(, BlockBackend) monitor_block_backends = |
119 | QTAILQ_HEAD_INITIALIZER(monitor_block_backends); |
120 | |
121 | static void blk_root_inherit_options(int *child_flags, QDict *child_options, |
122 | int parent_flags, QDict *parent_options) |
123 | { |
124 | /* We're not supposed to call this function for root nodes */ |
125 | abort(); |
126 | } |
127 | static void blk_root_drained_begin(BdrvChild *child); |
128 | static bool blk_root_drained_poll(BdrvChild *child); |
129 | static void blk_root_drained_end(BdrvChild *child, int *drained_end_counter); |
130 | |
131 | static void blk_root_change_media(BdrvChild *child, bool load); |
132 | static void blk_root_resize(BdrvChild *child); |
133 | |
134 | static bool blk_root_can_set_aio_ctx(BdrvChild *child, AioContext *ctx, |
135 | GSList **ignore, Error **errp); |
136 | static void blk_root_set_aio_ctx(BdrvChild *child, AioContext *ctx, |
137 | GSList **ignore); |
138 | |
139 | static char *blk_root_get_parent_desc(BdrvChild *child) |
140 | { |
141 | BlockBackend *blk = child->opaque; |
142 | char *dev_id; |
143 | |
144 | if (blk->name) { |
145 | return g_strdup(blk->name); |
146 | } |
147 | |
148 | dev_id = blk_get_attached_dev_id(blk); |
149 | if (*dev_id) { |
150 | return dev_id; |
151 | } else { |
152 | /* TODO Callback into the BB owner for something more detailed */ |
153 | g_free(dev_id); |
154 | return g_strdup("a block device" ); |
155 | } |
156 | } |
157 | |
158 | static const char *blk_root_get_name(BdrvChild *child) |
159 | { |
160 | return blk_name(child->opaque); |
161 | } |
162 | |
163 | static void blk_vm_state_changed(void *opaque, int running, RunState state) |
164 | { |
165 | Error *local_err = NULL; |
166 | BlockBackend *blk = opaque; |
167 | |
168 | if (state == RUN_STATE_INMIGRATE) { |
169 | return; |
170 | } |
171 | |
172 | qemu_del_vm_change_state_handler(blk->vmsh); |
173 | blk->vmsh = NULL; |
174 | blk_set_perm(blk, blk->perm, blk->shared_perm, &local_err); |
175 | if (local_err) { |
176 | error_report_err(local_err); |
177 | } |
178 | } |
179 | |
180 | /* |
181 | * Notifies the user of the BlockBackend that migration has completed. qdev |
182 | * devices can tighten their permissions in response (specifically revoke |
183 | * shared write permissions that we needed for storage migration). |
184 | * |
185 | * If an error is returned, the VM cannot be allowed to be resumed. |
186 | */ |
187 | static void blk_root_activate(BdrvChild *child, Error **errp) |
188 | { |
189 | BlockBackend *blk = child->opaque; |
190 | Error *local_err = NULL; |
191 | |
192 | if (!blk->disable_perm) { |
193 | return; |
194 | } |
195 | |
196 | blk->disable_perm = false; |
197 | |
198 | blk_set_perm(blk, blk->perm, BLK_PERM_ALL, &local_err); |
199 | if (local_err) { |
200 | error_propagate(errp, local_err); |
201 | blk->disable_perm = true; |
202 | return; |
203 | } |
204 | |
205 | if (runstate_check(RUN_STATE_INMIGRATE)) { |
206 | /* Activation can happen when migration process is still active, for |
207 | * example when nbd_server_add is called during non-shared storage |
208 | * migration. Defer the shared_perm update to migration completion. */ |
209 | if (!blk->vmsh) { |
210 | blk->vmsh = qemu_add_vm_change_state_handler(blk_vm_state_changed, |
211 | blk); |
212 | } |
213 | return; |
214 | } |
215 | |
216 | blk_set_perm(blk, blk->perm, blk->shared_perm, &local_err); |
217 | if (local_err) { |
218 | error_propagate(errp, local_err); |
219 | blk->disable_perm = true; |
220 | return; |
221 | } |
222 | } |
223 | |
224 | void blk_set_force_allow_inactivate(BlockBackend *blk) |
225 | { |
226 | blk->force_allow_inactivate = true; |
227 | } |
228 | |
229 | static bool blk_can_inactivate(BlockBackend *blk) |
230 | { |
231 | /* If it is a guest device, inactivate is ok. */ |
232 | if (blk->dev || blk_name(blk)[0]) { |
233 | return true; |
234 | } |
235 | |
236 | /* Inactivating means no more writes to the image can be done, |
237 | * even if those writes would be changes invisible to the |
238 | * guest. For block job BBs that satisfy this, we can just allow |
239 | * it. This is the case for mirror job source, which is required |
240 | * by libvirt non-shared block migration. */ |
241 | if (!(blk->perm & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED))) { |
242 | return true; |
243 | } |
244 | |
245 | return blk->force_allow_inactivate; |
246 | } |
247 | |
248 | static int blk_root_inactivate(BdrvChild *child) |
249 | { |
250 | BlockBackend *blk = child->opaque; |
251 | |
252 | if (blk->disable_perm) { |
253 | return 0; |
254 | } |
255 | |
256 | if (!blk_can_inactivate(blk)) { |
257 | return -EPERM; |
258 | } |
259 | |
260 | blk->disable_perm = true; |
261 | if (blk->root) { |
262 | bdrv_child_try_set_perm(blk->root, 0, BLK_PERM_ALL, &error_abort); |
263 | } |
264 | |
265 | return 0; |
266 | } |
267 | |
268 | static void blk_root_attach(BdrvChild *child) |
269 | { |
270 | BlockBackend *blk = child->opaque; |
271 | BlockBackendAioNotifier *notifier; |
272 | |
273 | trace_blk_root_attach(child, blk, child->bs); |
274 | |
275 | QLIST_FOREACH(notifier, &blk->aio_notifiers, list) { |
276 | bdrv_add_aio_context_notifier(child->bs, |
277 | notifier->attached_aio_context, |
278 | notifier->detach_aio_context, |
279 | notifier->opaque); |
280 | } |
281 | } |
282 | |
283 | static void blk_root_detach(BdrvChild *child) |
284 | { |
285 | BlockBackend *blk = child->opaque; |
286 | BlockBackendAioNotifier *notifier; |
287 | |
288 | trace_blk_root_detach(child, blk, child->bs); |
289 | |
290 | QLIST_FOREACH(notifier, &blk->aio_notifiers, list) { |
291 | bdrv_remove_aio_context_notifier(child->bs, |
292 | notifier->attached_aio_context, |
293 | notifier->detach_aio_context, |
294 | notifier->opaque); |
295 | } |
296 | } |
297 | |
298 | static const BdrvChildRole child_root = { |
299 | .inherit_options = blk_root_inherit_options, |
300 | |
301 | .change_media = blk_root_change_media, |
302 | .resize = blk_root_resize, |
303 | .get_name = blk_root_get_name, |
304 | .get_parent_desc = blk_root_get_parent_desc, |
305 | |
306 | .drained_begin = blk_root_drained_begin, |
307 | .drained_poll = blk_root_drained_poll, |
308 | .drained_end = blk_root_drained_end, |
309 | |
310 | .activate = blk_root_activate, |
311 | .inactivate = blk_root_inactivate, |
312 | |
313 | .attach = blk_root_attach, |
314 | .detach = blk_root_detach, |
315 | |
316 | .can_set_aio_ctx = blk_root_can_set_aio_ctx, |
317 | .set_aio_ctx = blk_root_set_aio_ctx, |
318 | }; |
319 | |
320 | /* |
321 | * Create a new BlockBackend with a reference count of one. |
322 | * |
323 | * @perm is a bitmasks of BLK_PERM_* constants which describes the permissions |
324 | * to request for a block driver node that is attached to this BlockBackend. |
325 | * @shared_perm is a bitmask which describes which permissions may be granted |
326 | * to other users of the attached node. |
327 | * Both sets of permissions can be changed later using blk_set_perm(). |
328 | * |
329 | * Return the new BlockBackend on success, null on failure. |
330 | */ |
331 | BlockBackend *blk_new(AioContext *ctx, uint64_t perm, uint64_t shared_perm) |
332 | { |
333 | BlockBackend *blk; |
334 | |
335 | blk = g_new0(BlockBackend, 1); |
336 | blk->refcnt = 1; |
337 | blk->ctx = ctx; |
338 | blk->perm = perm; |
339 | blk->shared_perm = shared_perm; |
340 | blk_set_enable_write_cache(blk, true); |
341 | |
342 | blk->on_read_error = BLOCKDEV_ON_ERROR_REPORT; |
343 | blk->on_write_error = BLOCKDEV_ON_ERROR_ENOSPC; |
344 | |
345 | block_acct_init(&blk->stats); |
346 | |
347 | qemu_co_queue_init(&blk->queued_requests); |
348 | notifier_list_init(&blk->remove_bs_notifiers); |
349 | notifier_list_init(&blk->insert_bs_notifiers); |
350 | QLIST_INIT(&blk->aio_notifiers); |
351 | |
352 | QTAILQ_INSERT_TAIL(&block_backends, blk, link); |
353 | return blk; |
354 | } |
355 | |
356 | /* |
357 | * Creates a new BlockBackend, opens a new BlockDriverState, and connects both. |
358 | * The new BlockBackend is in the main AioContext. |
359 | * |
360 | * Just as with bdrv_open(), after having called this function the reference to |
361 | * @options belongs to the block layer (even on failure). |
362 | * |
363 | * TODO: Remove @filename and @flags; it should be possible to specify a whole |
364 | * BDS tree just by specifying the @options QDict (or @reference, |
365 | * alternatively). At the time of adding this function, this is not possible, |
366 | * though, so callers of this function have to be able to specify @filename and |
367 | * @flags. |
368 | */ |
369 | BlockBackend *blk_new_open(const char *filename, const char *reference, |
370 | QDict *options, int flags, Error **errp) |
371 | { |
372 | BlockBackend *blk; |
373 | BlockDriverState *bs; |
374 | uint64_t perm = 0; |
375 | |
376 | /* blk_new_open() is mainly used in .bdrv_create implementations and the |
377 | * tools where sharing isn't a concern because the BDS stays private, so we |
378 | * just request permission according to the flags. |
379 | * |
380 | * The exceptions are xen_disk and blockdev_init(); in these cases, the |
381 | * caller of blk_new_open() doesn't make use of the permissions, but they |
382 | * shouldn't hurt either. We can still share everything here because the |
383 | * guest devices will add their own blockers if they can't share. */ |
384 | if ((flags & BDRV_O_NO_IO) == 0) { |
385 | perm |= BLK_PERM_CONSISTENT_READ; |
386 | if (flags & BDRV_O_RDWR) { |
387 | perm |= BLK_PERM_WRITE; |
388 | } |
389 | } |
390 | if (flags & BDRV_O_RESIZE) { |
391 | perm |= BLK_PERM_RESIZE; |
392 | } |
393 | |
394 | blk = blk_new(qemu_get_aio_context(), perm, BLK_PERM_ALL); |
395 | bs = bdrv_open(filename, reference, options, flags, errp); |
396 | if (!bs) { |
397 | blk_unref(blk); |
398 | return NULL; |
399 | } |
400 | |
401 | blk->root = bdrv_root_attach_child(bs, "root" , &child_root, blk->ctx, |
402 | perm, BLK_PERM_ALL, blk, errp); |
403 | if (!blk->root) { |
404 | blk_unref(blk); |
405 | return NULL; |
406 | } |
407 | |
408 | return blk; |
409 | } |
410 | |
411 | static void blk_delete(BlockBackend *blk) |
412 | { |
413 | assert(!blk->refcnt); |
414 | assert(!blk->name); |
415 | assert(!blk->dev); |
416 | if (blk->public.throttle_group_member.throttle_state) { |
417 | blk_io_limits_disable(blk); |
418 | } |
419 | if (blk->root) { |
420 | blk_remove_bs(blk); |
421 | } |
422 | if (blk->vmsh) { |
423 | qemu_del_vm_change_state_handler(blk->vmsh); |
424 | blk->vmsh = NULL; |
425 | } |
426 | assert(QLIST_EMPTY(&blk->remove_bs_notifiers.notifiers)); |
427 | assert(QLIST_EMPTY(&blk->insert_bs_notifiers.notifiers)); |
428 | assert(QLIST_EMPTY(&blk->aio_notifiers)); |
429 | QTAILQ_REMOVE(&block_backends, blk, link); |
430 | drive_info_del(blk->legacy_dinfo); |
431 | block_acct_cleanup(&blk->stats); |
432 | g_free(blk); |
433 | } |
434 | |
435 | static void drive_info_del(DriveInfo *dinfo) |
436 | { |
437 | if (!dinfo) { |
438 | return; |
439 | } |
440 | qemu_opts_del(dinfo->opts); |
441 | g_free(dinfo); |
442 | } |
443 | |
444 | int blk_get_refcnt(BlockBackend *blk) |
445 | { |
446 | return blk ? blk->refcnt : 0; |
447 | } |
448 | |
449 | /* |
450 | * Increment @blk's reference count. |
451 | * @blk must not be null. |
452 | */ |
453 | void blk_ref(BlockBackend *blk) |
454 | { |
455 | assert(blk->refcnt > 0); |
456 | blk->refcnt++; |
457 | } |
458 | |
459 | /* |
460 | * Decrement @blk's reference count. |
461 | * If this drops it to zero, destroy @blk. |
462 | * For convenience, do nothing if @blk is null. |
463 | */ |
464 | void blk_unref(BlockBackend *blk) |
465 | { |
466 | if (blk) { |
467 | assert(blk->refcnt > 0); |
468 | if (blk->refcnt > 1) { |
469 | blk->refcnt--; |
470 | } else { |
471 | blk_drain(blk); |
472 | /* blk_drain() cannot resurrect blk, nobody held a reference */ |
473 | assert(blk->refcnt == 1); |
474 | blk->refcnt = 0; |
475 | blk_delete(blk); |
476 | } |
477 | } |
478 | } |
479 | |
480 | /* |
481 | * Behaves similarly to blk_next() but iterates over all BlockBackends, even the |
482 | * ones which are hidden (i.e. are not referenced by the monitor). |
483 | */ |
484 | BlockBackend *blk_all_next(BlockBackend *blk) |
485 | { |
486 | return blk ? QTAILQ_NEXT(blk, link) |
487 | : QTAILQ_FIRST(&block_backends); |
488 | } |
489 | |
490 | void blk_remove_all_bs(void) |
491 | { |
492 | BlockBackend *blk = NULL; |
493 | |
494 | while ((blk = blk_all_next(blk)) != NULL) { |
495 | AioContext *ctx = blk_get_aio_context(blk); |
496 | |
497 | aio_context_acquire(ctx); |
498 | if (blk->root) { |
499 | blk_remove_bs(blk); |
500 | } |
501 | aio_context_release(ctx); |
502 | } |
503 | } |
504 | |
505 | /* |
506 | * Return the monitor-owned BlockBackend after @blk. |
507 | * If @blk is null, return the first one. |
508 | * Else, return @blk's next sibling, which may be null. |
509 | * |
510 | * To iterate over all BlockBackends, do |
511 | * for (blk = blk_next(NULL); blk; blk = blk_next(blk)) { |
512 | * ... |
513 | * } |
514 | */ |
515 | BlockBackend *blk_next(BlockBackend *blk) |
516 | { |
517 | return blk ? QTAILQ_NEXT(blk, monitor_link) |
518 | : QTAILQ_FIRST(&monitor_block_backends); |
519 | } |
520 | |
521 | /* Iterates over all top-level BlockDriverStates, i.e. BDSs that are owned by |
522 | * the monitor or attached to a BlockBackend */ |
523 | BlockDriverState *bdrv_next(BdrvNextIterator *it) |
524 | { |
525 | BlockDriverState *bs, *old_bs; |
526 | |
527 | /* Must be called from the main loop */ |
528 | assert(qemu_get_current_aio_context() == qemu_get_aio_context()); |
529 | |
530 | /* First, return all root nodes of BlockBackends. In order to avoid |
531 | * returning a BDS twice when multiple BBs refer to it, we only return it |
532 | * if the BB is the first one in the parent list of the BDS. */ |
533 | if (it->phase == BDRV_NEXT_BACKEND_ROOTS) { |
534 | BlockBackend *old_blk = it->blk; |
535 | |
536 | old_bs = old_blk ? blk_bs(old_blk) : NULL; |
537 | |
538 | do { |
539 | it->blk = blk_all_next(it->blk); |
540 | bs = it->blk ? blk_bs(it->blk) : NULL; |
541 | } while (it->blk && (bs == NULL || bdrv_first_blk(bs) != it->blk)); |
542 | |
543 | if (it->blk) { |
544 | blk_ref(it->blk); |
545 | } |
546 | blk_unref(old_blk); |
547 | |
548 | if (bs) { |
549 | bdrv_ref(bs); |
550 | bdrv_unref(old_bs); |
551 | return bs; |
552 | } |
553 | it->phase = BDRV_NEXT_MONITOR_OWNED; |
554 | } else { |
555 | old_bs = it->bs; |
556 | } |
557 | |
558 | /* Then return the monitor-owned BDSes without a BB attached. Ignore all |
559 | * BDSes that are attached to a BlockBackend here; they have been handled |
560 | * by the above block already */ |
561 | do { |
562 | it->bs = bdrv_next_monitor_owned(it->bs); |
563 | bs = it->bs; |
564 | } while (bs && bdrv_has_blk(bs)); |
565 | |
566 | if (bs) { |
567 | bdrv_ref(bs); |
568 | } |
569 | bdrv_unref(old_bs); |
570 | |
571 | return bs; |
572 | } |
573 | |
574 | static void bdrv_next_reset(BdrvNextIterator *it) |
575 | { |
576 | *it = (BdrvNextIterator) { |
577 | .phase = BDRV_NEXT_BACKEND_ROOTS, |
578 | }; |
579 | } |
580 | |
581 | BlockDriverState *bdrv_first(BdrvNextIterator *it) |
582 | { |
583 | bdrv_next_reset(it); |
584 | return bdrv_next(it); |
585 | } |
586 | |
587 | /* Must be called when aborting a bdrv_next() iteration before |
588 | * bdrv_next() returns NULL */ |
589 | void bdrv_next_cleanup(BdrvNextIterator *it) |
590 | { |
591 | /* Must be called from the main loop */ |
592 | assert(qemu_get_current_aio_context() == qemu_get_aio_context()); |
593 | |
594 | if (it->phase == BDRV_NEXT_BACKEND_ROOTS) { |
595 | if (it->blk) { |
596 | bdrv_unref(blk_bs(it->blk)); |
597 | blk_unref(it->blk); |
598 | } |
599 | } else { |
600 | bdrv_unref(it->bs); |
601 | } |
602 | |
603 | bdrv_next_reset(it); |
604 | } |
605 | |
606 | /* |
607 | * Add a BlockBackend into the list of backends referenced by the monitor, with |
608 | * the given @name acting as the handle for the monitor. |
609 | * Strictly for use by blockdev.c. |
610 | * |
611 | * @name must not be null or empty. |
612 | * |
613 | * Returns true on success and false on failure. In the latter case, an Error |
614 | * object is returned through @errp. |
615 | */ |
616 | bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp) |
617 | { |
618 | assert(!blk->name); |
619 | assert(name && name[0]); |
620 | |
621 | if (!id_wellformed(name)) { |
622 | error_setg(errp, "Invalid device name" ); |
623 | return false; |
624 | } |
625 | if (blk_by_name(name)) { |
626 | error_setg(errp, "Device with id '%s' already exists" , name); |
627 | return false; |
628 | } |
629 | if (bdrv_find_node(name)) { |
630 | error_setg(errp, |
631 | "Device name '%s' conflicts with an existing node name" , |
632 | name); |
633 | return false; |
634 | } |
635 | |
636 | blk->name = g_strdup(name); |
637 | QTAILQ_INSERT_TAIL(&monitor_block_backends, blk, monitor_link); |
638 | return true; |
639 | } |
640 | |
641 | /* |
642 | * Remove a BlockBackend from the list of backends referenced by the monitor. |
643 | * Strictly for use by blockdev.c. |
644 | */ |
645 | void monitor_remove_blk(BlockBackend *blk) |
646 | { |
647 | if (!blk->name) { |
648 | return; |
649 | } |
650 | |
651 | QTAILQ_REMOVE(&monitor_block_backends, blk, monitor_link); |
652 | g_free(blk->name); |
653 | blk->name = NULL; |
654 | } |
655 | |
656 | /* |
657 | * Return @blk's name, a non-null string. |
658 | * Returns an empty string iff @blk is not referenced by the monitor. |
659 | */ |
660 | const char *blk_name(const BlockBackend *blk) |
661 | { |
662 | return blk->name ?: "" ; |
663 | } |
664 | |
665 | /* |
666 | * Return the BlockBackend with name @name if it exists, else null. |
667 | * @name must not be null. |
668 | */ |
669 | BlockBackend *blk_by_name(const char *name) |
670 | { |
671 | BlockBackend *blk = NULL; |
672 | |
673 | assert(name); |
674 | while ((blk = blk_next(blk)) != NULL) { |
675 | if (!strcmp(name, blk->name)) { |
676 | return blk; |
677 | } |
678 | } |
679 | return NULL; |
680 | } |
681 | |
682 | /* |
683 | * Return the BlockDriverState attached to @blk if any, else null. |
684 | */ |
685 | BlockDriverState *blk_bs(BlockBackend *blk) |
686 | { |
687 | return blk->root ? blk->root->bs : NULL; |
688 | } |
689 | |
690 | static BlockBackend *bdrv_first_blk(BlockDriverState *bs) |
691 | { |
692 | BdrvChild *child; |
693 | QLIST_FOREACH(child, &bs->parents, next_parent) { |
694 | if (child->role == &child_root) { |
695 | return child->opaque; |
696 | } |
697 | } |
698 | |
699 | return NULL; |
700 | } |
701 | |
702 | /* |
703 | * Returns true if @bs has an associated BlockBackend. |
704 | */ |
705 | bool bdrv_has_blk(BlockDriverState *bs) |
706 | { |
707 | return bdrv_first_blk(bs) != NULL; |
708 | } |
709 | |
710 | /* |
711 | * Returns true if @bs has only BlockBackends as parents. |
712 | */ |
713 | bool bdrv_is_root_node(BlockDriverState *bs) |
714 | { |
715 | BdrvChild *c; |
716 | |
717 | QLIST_FOREACH(c, &bs->parents, next_parent) { |
718 | if (c->role != &child_root) { |
719 | return false; |
720 | } |
721 | } |
722 | |
723 | return true; |
724 | } |
725 | |
726 | /* |
727 | * Return @blk's DriveInfo if any, else null. |
728 | */ |
729 | DriveInfo *blk_legacy_dinfo(BlockBackend *blk) |
730 | { |
731 | return blk->legacy_dinfo; |
732 | } |
733 | |
734 | /* |
735 | * Set @blk's DriveInfo to @dinfo, and return it. |
736 | * @blk must not have a DriveInfo set already. |
737 | * No other BlockBackend may have the same DriveInfo set. |
738 | */ |
739 | DriveInfo *blk_set_legacy_dinfo(BlockBackend *blk, DriveInfo *dinfo) |
740 | { |
741 | assert(!blk->legacy_dinfo); |
742 | return blk->legacy_dinfo = dinfo; |
743 | } |
744 | |
745 | /* |
746 | * Return the BlockBackend with DriveInfo @dinfo. |
747 | * It must exist. |
748 | */ |
749 | BlockBackend *blk_by_legacy_dinfo(DriveInfo *dinfo) |
750 | { |
751 | BlockBackend *blk = NULL; |
752 | |
753 | while ((blk = blk_next(blk)) != NULL) { |
754 | if (blk->legacy_dinfo == dinfo) { |
755 | return blk; |
756 | } |
757 | } |
758 | abort(); |
759 | } |
760 | |
761 | /* |
762 | * Returns a pointer to the publicly accessible fields of @blk. |
763 | */ |
764 | BlockBackendPublic *blk_get_public(BlockBackend *blk) |
765 | { |
766 | return &blk->public; |
767 | } |
768 | |
769 | /* |
770 | * Returns a BlockBackend given the associated @public fields. |
771 | */ |
772 | BlockBackend *blk_by_public(BlockBackendPublic *public) |
773 | { |
774 | return container_of(public, BlockBackend, public); |
775 | } |
776 | |
777 | /* |
778 | * Disassociates the currently associated BlockDriverState from @blk. |
779 | */ |
780 | void blk_remove_bs(BlockBackend *blk) |
781 | { |
782 | ThrottleGroupMember *tgm = &blk->public.throttle_group_member; |
783 | BlockDriverState *bs; |
784 | |
785 | notifier_list_notify(&blk->remove_bs_notifiers, blk); |
786 | if (tgm->throttle_state) { |
787 | bs = blk_bs(blk); |
788 | bdrv_drained_begin(bs); |
789 | throttle_group_detach_aio_context(tgm); |
790 | throttle_group_attach_aio_context(tgm, qemu_get_aio_context()); |
791 | bdrv_drained_end(bs); |
792 | } |
793 | |
794 | blk_update_root_state(blk); |
795 | |
796 | /* bdrv_root_unref_child() will cause blk->root to become stale and may |
797 | * switch to a completion coroutine later on. Let's drain all I/O here |
798 | * to avoid that and a potential QEMU crash. |
799 | */ |
800 | blk_drain(blk); |
801 | bdrv_root_unref_child(blk->root); |
802 | blk->root = NULL; |
803 | } |
804 | |
805 | /* |
806 | * Associates a new BlockDriverState with @blk. |
807 | */ |
808 | int blk_insert_bs(BlockBackend *blk, BlockDriverState *bs, Error **errp) |
809 | { |
810 | ThrottleGroupMember *tgm = &blk->public.throttle_group_member; |
811 | bdrv_ref(bs); |
812 | blk->root = bdrv_root_attach_child(bs, "root" , &child_root, blk->ctx, |
813 | blk->perm, blk->shared_perm, blk, errp); |
814 | if (blk->root == NULL) { |
815 | return -EPERM; |
816 | } |
817 | |
818 | notifier_list_notify(&blk->insert_bs_notifiers, blk); |
819 | if (tgm->throttle_state) { |
820 | throttle_group_detach_aio_context(tgm); |
821 | throttle_group_attach_aio_context(tgm, bdrv_get_aio_context(bs)); |
822 | } |
823 | |
824 | return 0; |
825 | } |
826 | |
827 | /* |
828 | * Sets the permission bitmasks that the user of the BlockBackend needs. |
829 | */ |
830 | int blk_set_perm(BlockBackend *blk, uint64_t perm, uint64_t shared_perm, |
831 | Error **errp) |
832 | { |
833 | int ret; |
834 | |
835 | if (blk->root && !blk->disable_perm) { |
836 | ret = bdrv_child_try_set_perm(blk->root, perm, shared_perm, errp); |
837 | if (ret < 0) { |
838 | return ret; |
839 | } |
840 | } |
841 | |
842 | blk->perm = perm; |
843 | blk->shared_perm = shared_perm; |
844 | |
845 | return 0; |
846 | } |
847 | |
848 | void blk_get_perm(BlockBackend *blk, uint64_t *perm, uint64_t *shared_perm) |
849 | { |
850 | *perm = blk->perm; |
851 | *shared_perm = blk->shared_perm; |
852 | } |
853 | |
854 | /* |
855 | * Attach device model @dev to @blk. |
856 | * Return 0 on success, -EBUSY when a device model is attached already. |
857 | */ |
858 | int blk_attach_dev(BlockBackend *blk, DeviceState *dev) |
859 | { |
860 | if (blk->dev) { |
861 | return -EBUSY; |
862 | } |
863 | |
864 | /* While migration is still incoming, we don't need to apply the |
865 | * permissions of guest device BlockBackends. We might still have a block |
866 | * job or NBD server writing to the image for storage migration. */ |
867 | if (runstate_check(RUN_STATE_INMIGRATE)) { |
868 | blk->disable_perm = true; |
869 | } |
870 | |
871 | blk_ref(blk); |
872 | blk->dev = dev; |
873 | blk_iostatus_reset(blk); |
874 | |
875 | return 0; |
876 | } |
877 | |
878 | /* |
879 | * Detach device model @dev from @blk. |
880 | * @dev must be currently attached to @blk. |
881 | */ |
882 | void blk_detach_dev(BlockBackend *blk, DeviceState *dev) |
883 | { |
884 | assert(blk->dev == dev); |
885 | blk->dev = NULL; |
886 | blk->dev_ops = NULL; |
887 | blk->dev_opaque = NULL; |
888 | blk->guest_block_size = 512; |
889 | blk_set_perm(blk, 0, BLK_PERM_ALL, &error_abort); |
890 | blk_unref(blk); |
891 | } |
892 | |
893 | /* |
894 | * Return the device model attached to @blk if any, else null. |
895 | */ |
896 | DeviceState *blk_get_attached_dev(BlockBackend *blk) |
897 | { |
898 | return blk->dev; |
899 | } |
900 | |
901 | /* Return the qdev ID, or if no ID is assigned the QOM path, of the block |
902 | * device attached to the BlockBackend. */ |
903 | char *blk_get_attached_dev_id(BlockBackend *blk) |
904 | { |
905 | DeviceState *dev = blk->dev; |
906 | |
907 | if (!dev) { |
908 | return g_strdup("" ); |
909 | } else if (dev->id) { |
910 | return g_strdup(dev->id); |
911 | } |
912 | |
913 | return object_get_canonical_path(OBJECT(dev)) ?: g_strdup("" ); |
914 | } |
915 | |
916 | /* |
917 | * Return the BlockBackend which has the device model @dev attached if it |
918 | * exists, else null. |
919 | * |
920 | * @dev must not be null. |
921 | */ |
922 | BlockBackend *blk_by_dev(void *dev) |
923 | { |
924 | BlockBackend *blk = NULL; |
925 | |
926 | assert(dev != NULL); |
927 | while ((blk = blk_all_next(blk)) != NULL) { |
928 | if (blk->dev == dev) { |
929 | return blk; |
930 | } |
931 | } |
932 | return NULL; |
933 | } |
934 | |
935 | /* |
936 | * Set @blk's device model callbacks to @ops. |
937 | * @opaque is the opaque argument to pass to the callbacks. |
938 | * This is for use by device models. |
939 | */ |
940 | void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops, |
941 | void *opaque) |
942 | { |
943 | blk->dev_ops = ops; |
944 | blk->dev_opaque = opaque; |
945 | |
946 | /* Are we currently quiesced? Should we enforce this right now? */ |
947 | if (blk->quiesce_counter && ops->drained_begin) { |
948 | ops->drained_begin(opaque); |
949 | } |
950 | } |
951 | |
952 | /* |
953 | * Notify @blk's attached device model of media change. |
954 | * |
955 | * If @load is true, notify of media load. This action can fail, meaning that |
956 | * the medium cannot be loaded. @errp is set then. |
957 | * |
958 | * If @load is false, notify of media eject. This can never fail. |
959 | * |
960 | * Also send DEVICE_TRAY_MOVED events as appropriate. |
961 | */ |
962 | void blk_dev_change_media_cb(BlockBackend *blk, bool load, Error **errp) |
963 | { |
964 | if (blk->dev_ops && blk->dev_ops->change_media_cb) { |
965 | bool tray_was_open, tray_is_open; |
966 | Error *local_err = NULL; |
967 | |
968 | tray_was_open = blk_dev_is_tray_open(blk); |
969 | blk->dev_ops->change_media_cb(blk->dev_opaque, load, &local_err); |
970 | if (local_err) { |
971 | assert(load == true); |
972 | error_propagate(errp, local_err); |
973 | return; |
974 | } |
975 | tray_is_open = blk_dev_is_tray_open(blk); |
976 | |
977 | if (tray_was_open != tray_is_open) { |
978 | char *id = blk_get_attached_dev_id(blk); |
979 | qapi_event_send_device_tray_moved(blk_name(blk), id, tray_is_open); |
980 | g_free(id); |
981 | } |
982 | } |
983 | } |
984 | |
985 | static void blk_root_change_media(BdrvChild *child, bool load) |
986 | { |
987 | blk_dev_change_media_cb(child->opaque, load, NULL); |
988 | } |
989 | |
990 | /* |
991 | * Does @blk's attached device model have removable media? |
992 | * %true if no device model is attached. |
993 | */ |
994 | bool blk_dev_has_removable_media(BlockBackend *blk) |
995 | { |
996 | return !blk->dev || (blk->dev_ops && blk->dev_ops->change_media_cb); |
997 | } |
998 | |
999 | /* |
1000 | * Does @blk's attached device model have a tray? |
1001 | */ |
1002 | bool blk_dev_has_tray(BlockBackend *blk) |
1003 | { |
1004 | return blk->dev_ops && blk->dev_ops->is_tray_open; |
1005 | } |
1006 | |
1007 | /* |
1008 | * Notify @blk's attached device model of a media eject request. |
1009 | * If @force is true, the medium is about to be yanked out forcefully. |
1010 | */ |
1011 | void blk_dev_eject_request(BlockBackend *blk, bool force) |
1012 | { |
1013 | if (blk->dev_ops && blk->dev_ops->eject_request_cb) { |
1014 | blk->dev_ops->eject_request_cb(blk->dev_opaque, force); |
1015 | } |
1016 | } |
1017 | |
1018 | /* |
1019 | * Does @blk's attached device model have a tray, and is it open? |
1020 | */ |
1021 | bool blk_dev_is_tray_open(BlockBackend *blk) |
1022 | { |
1023 | if (blk_dev_has_tray(blk)) { |
1024 | return blk->dev_ops->is_tray_open(blk->dev_opaque); |
1025 | } |
1026 | return false; |
1027 | } |
1028 | |
1029 | /* |
1030 | * Does @blk's attached device model have the medium locked? |
1031 | * %false if the device model has no such lock. |
1032 | */ |
1033 | bool blk_dev_is_medium_locked(BlockBackend *blk) |
1034 | { |
1035 | if (blk->dev_ops && blk->dev_ops->is_medium_locked) { |
1036 | return blk->dev_ops->is_medium_locked(blk->dev_opaque); |
1037 | } |
1038 | return false; |
1039 | } |
1040 | |
1041 | /* |
1042 | * Notify @blk's attached device model of a backend size change. |
1043 | */ |
1044 | static void blk_root_resize(BdrvChild *child) |
1045 | { |
1046 | BlockBackend *blk = child->opaque; |
1047 | |
1048 | if (blk->dev_ops && blk->dev_ops->resize_cb) { |
1049 | blk->dev_ops->resize_cb(blk->dev_opaque); |
1050 | } |
1051 | } |
1052 | |
1053 | void blk_iostatus_enable(BlockBackend *blk) |
1054 | { |
1055 | blk->iostatus_enabled = true; |
1056 | blk->iostatus = BLOCK_DEVICE_IO_STATUS_OK; |
1057 | } |
1058 | |
1059 | /* The I/O status is only enabled if the drive explicitly |
1060 | * enables it _and_ the VM is configured to stop on errors */ |
1061 | bool blk_iostatus_is_enabled(const BlockBackend *blk) |
1062 | { |
1063 | return (blk->iostatus_enabled && |
1064 | (blk->on_write_error == BLOCKDEV_ON_ERROR_ENOSPC || |
1065 | blk->on_write_error == BLOCKDEV_ON_ERROR_STOP || |
1066 | blk->on_read_error == BLOCKDEV_ON_ERROR_STOP)); |
1067 | } |
1068 | |
1069 | BlockDeviceIoStatus blk_iostatus(const BlockBackend *blk) |
1070 | { |
1071 | return blk->iostatus; |
1072 | } |
1073 | |
1074 | void blk_iostatus_disable(BlockBackend *blk) |
1075 | { |
1076 | blk->iostatus_enabled = false; |
1077 | } |
1078 | |
1079 | void blk_iostatus_reset(BlockBackend *blk) |
1080 | { |
1081 | if (blk_iostatus_is_enabled(blk)) { |
1082 | blk->iostatus = BLOCK_DEVICE_IO_STATUS_OK; |
1083 | } |
1084 | } |
1085 | |
1086 | void blk_iostatus_set_err(BlockBackend *blk, int error) |
1087 | { |
1088 | assert(blk_iostatus_is_enabled(blk)); |
1089 | if (blk->iostatus == BLOCK_DEVICE_IO_STATUS_OK) { |
1090 | blk->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE : |
1091 | BLOCK_DEVICE_IO_STATUS_FAILED; |
1092 | } |
1093 | } |
1094 | |
1095 | void blk_set_allow_write_beyond_eof(BlockBackend *blk, bool allow) |
1096 | { |
1097 | blk->allow_write_beyond_eof = allow; |
1098 | } |
1099 | |
1100 | void blk_set_allow_aio_context_change(BlockBackend *blk, bool allow) |
1101 | { |
1102 | blk->allow_aio_context_change = allow; |
1103 | } |
1104 | |
1105 | void blk_set_disable_request_queuing(BlockBackend *blk, bool disable) |
1106 | { |
1107 | blk->disable_request_queuing = disable; |
1108 | } |
1109 | |
1110 | static int blk_check_byte_request(BlockBackend *blk, int64_t offset, |
1111 | size_t size) |
1112 | { |
1113 | int64_t len; |
1114 | |
1115 | if (size > INT_MAX) { |
1116 | return -EIO; |
1117 | } |
1118 | |
1119 | if (!blk_is_available(blk)) { |
1120 | return -ENOMEDIUM; |
1121 | } |
1122 | |
1123 | if (offset < 0) { |
1124 | return -EIO; |
1125 | } |
1126 | |
1127 | if (!blk->allow_write_beyond_eof) { |
1128 | len = blk_getlength(blk); |
1129 | if (len < 0) { |
1130 | return len; |
1131 | } |
1132 | |
1133 | if (offset > len || len - offset < size) { |
1134 | return -EIO; |
1135 | } |
1136 | } |
1137 | |
1138 | return 0; |
1139 | } |
1140 | |
1141 | static void coroutine_fn blk_wait_while_drained(BlockBackend *blk) |
1142 | { |
1143 | if (blk->quiesce_counter && !blk->disable_request_queuing) { |
1144 | qemu_co_queue_wait(&blk->queued_requests, NULL); |
1145 | } |
1146 | } |
1147 | |
1148 | int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset, |
1149 | unsigned int bytes, QEMUIOVector *qiov, |
1150 | BdrvRequestFlags flags) |
1151 | { |
1152 | int ret; |
1153 | BlockDriverState *bs; |
1154 | |
1155 | blk_wait_while_drained(blk); |
1156 | |
1157 | /* Call blk_bs() only after waiting, the graph may have changed */ |
1158 | bs = blk_bs(blk); |
1159 | trace_blk_co_preadv(blk, bs, offset, bytes, flags); |
1160 | |
1161 | ret = blk_check_byte_request(blk, offset, bytes); |
1162 | if (ret < 0) { |
1163 | return ret; |
1164 | } |
1165 | |
1166 | bdrv_inc_in_flight(bs); |
1167 | |
1168 | /* throttling disk I/O */ |
1169 | if (blk->public.throttle_group_member.throttle_state) { |
1170 | throttle_group_co_io_limits_intercept(&blk->public.throttle_group_member, |
1171 | bytes, false); |
1172 | } |
1173 | |
1174 | ret = bdrv_co_preadv(blk->root, offset, bytes, qiov, flags); |
1175 | bdrv_dec_in_flight(bs); |
1176 | return ret; |
1177 | } |
1178 | |
1179 | int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset, |
1180 | unsigned int bytes, QEMUIOVector *qiov, |
1181 | BdrvRequestFlags flags) |
1182 | { |
1183 | int ret; |
1184 | BlockDriverState *bs; |
1185 | |
1186 | blk_wait_while_drained(blk); |
1187 | |
1188 | /* Call blk_bs() only after waiting, the graph may have changed */ |
1189 | bs = blk_bs(blk); |
1190 | trace_blk_co_pwritev(blk, bs, offset, bytes, flags); |
1191 | |
1192 | ret = blk_check_byte_request(blk, offset, bytes); |
1193 | if (ret < 0) { |
1194 | return ret; |
1195 | } |
1196 | |
1197 | bdrv_inc_in_flight(bs); |
1198 | /* throttling disk I/O */ |
1199 | if (blk->public.throttle_group_member.throttle_state) { |
1200 | throttle_group_co_io_limits_intercept(&blk->public.throttle_group_member, |
1201 | bytes, true); |
1202 | } |
1203 | |
1204 | if (!blk->enable_write_cache) { |
1205 | flags |= BDRV_REQ_FUA; |
1206 | } |
1207 | |
1208 | ret = bdrv_co_pwritev(blk->root, offset, bytes, qiov, flags); |
1209 | bdrv_dec_in_flight(bs); |
1210 | return ret; |
1211 | } |
1212 | |
1213 | typedef struct BlkRwCo { |
1214 | BlockBackend *blk; |
1215 | int64_t offset; |
1216 | void *iobuf; |
1217 | int ret; |
1218 | BdrvRequestFlags flags; |
1219 | } BlkRwCo; |
1220 | |
1221 | static void blk_read_entry(void *opaque) |
1222 | { |
1223 | BlkRwCo *rwco = opaque; |
1224 | QEMUIOVector *qiov = rwco->iobuf; |
1225 | |
1226 | rwco->ret = blk_co_preadv(rwco->blk, rwco->offset, qiov->size, |
1227 | qiov, rwco->flags); |
1228 | aio_wait_kick(); |
1229 | } |
1230 | |
1231 | static void blk_write_entry(void *opaque) |
1232 | { |
1233 | BlkRwCo *rwco = opaque; |
1234 | QEMUIOVector *qiov = rwco->iobuf; |
1235 | |
1236 | rwco->ret = blk_co_pwritev(rwco->blk, rwco->offset, qiov->size, |
1237 | qiov, rwco->flags); |
1238 | aio_wait_kick(); |
1239 | } |
1240 | |
1241 | static int blk_prw(BlockBackend *blk, int64_t offset, uint8_t *buf, |
1242 | int64_t bytes, CoroutineEntry co_entry, |
1243 | BdrvRequestFlags flags) |
1244 | { |
1245 | QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes); |
1246 | BlkRwCo rwco = { |
1247 | .blk = blk, |
1248 | .offset = offset, |
1249 | .iobuf = &qiov, |
1250 | .flags = flags, |
1251 | .ret = NOT_DONE, |
1252 | }; |
1253 | |
1254 | if (qemu_in_coroutine()) { |
1255 | /* Fast-path if already in coroutine context */ |
1256 | co_entry(&rwco); |
1257 | } else { |
1258 | Coroutine *co = qemu_coroutine_create(co_entry, &rwco); |
1259 | bdrv_coroutine_enter(blk_bs(blk), co); |
1260 | BDRV_POLL_WHILE(blk_bs(blk), rwco.ret == NOT_DONE); |
1261 | } |
1262 | |
1263 | return rwco.ret; |
1264 | } |
1265 | |
1266 | int blk_pwrite_zeroes(BlockBackend *blk, int64_t offset, |
1267 | int bytes, BdrvRequestFlags flags) |
1268 | { |
1269 | return blk_prw(blk, offset, NULL, bytes, blk_write_entry, |
1270 | flags | BDRV_REQ_ZERO_WRITE); |
1271 | } |
1272 | |
1273 | int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags) |
1274 | { |
1275 | return bdrv_make_zero(blk->root, flags); |
1276 | } |
1277 | |
1278 | void blk_inc_in_flight(BlockBackend *blk) |
1279 | { |
1280 | atomic_inc(&blk->in_flight); |
1281 | } |
1282 | |
1283 | void blk_dec_in_flight(BlockBackend *blk) |
1284 | { |
1285 | atomic_dec(&blk->in_flight); |
1286 | aio_wait_kick(); |
1287 | } |
1288 | |
1289 | static void error_callback_bh(void *opaque) |
1290 | { |
1291 | struct BlockBackendAIOCB *acb = opaque; |
1292 | |
1293 | blk_dec_in_flight(acb->blk); |
1294 | acb->common.cb(acb->common.opaque, acb->ret); |
1295 | qemu_aio_unref(acb); |
1296 | } |
1297 | |
1298 | BlockAIOCB *blk_abort_aio_request(BlockBackend *blk, |
1299 | BlockCompletionFunc *cb, |
1300 | void *opaque, int ret) |
1301 | { |
1302 | struct BlockBackendAIOCB *acb; |
1303 | |
1304 | blk_inc_in_flight(blk); |
1305 | acb = blk_aio_get(&block_backend_aiocb_info, blk, cb, opaque); |
1306 | acb->blk = blk; |
1307 | acb->ret = ret; |
1308 | |
1309 | aio_bh_schedule_oneshot(blk_get_aio_context(blk), error_callback_bh, acb); |
1310 | return &acb->common; |
1311 | } |
1312 | |
1313 | typedef struct BlkAioEmAIOCB { |
1314 | BlockAIOCB common; |
1315 | BlkRwCo rwco; |
1316 | int bytes; |
1317 | bool has_returned; |
1318 | } BlkAioEmAIOCB; |
1319 | |
1320 | static const AIOCBInfo blk_aio_em_aiocb_info = { |
1321 | .aiocb_size = sizeof(BlkAioEmAIOCB), |
1322 | }; |
1323 | |
1324 | static void blk_aio_complete(BlkAioEmAIOCB *acb) |
1325 | { |
1326 | if (acb->has_returned) { |
1327 | acb->common.cb(acb->common.opaque, acb->rwco.ret); |
1328 | blk_dec_in_flight(acb->rwco.blk); |
1329 | qemu_aio_unref(acb); |
1330 | } |
1331 | } |
1332 | |
1333 | static void blk_aio_complete_bh(void *opaque) |
1334 | { |
1335 | BlkAioEmAIOCB *acb = opaque; |
1336 | assert(acb->has_returned); |
1337 | blk_aio_complete(acb); |
1338 | } |
1339 | |
1340 | static BlockAIOCB *blk_aio_prwv(BlockBackend *blk, int64_t offset, int bytes, |
1341 | void *iobuf, CoroutineEntry co_entry, |
1342 | BdrvRequestFlags flags, |
1343 | BlockCompletionFunc *cb, void *opaque) |
1344 | { |
1345 | BlkAioEmAIOCB *acb; |
1346 | Coroutine *co; |
1347 | |
1348 | blk_inc_in_flight(blk); |
1349 | acb = blk_aio_get(&blk_aio_em_aiocb_info, blk, cb, opaque); |
1350 | acb->rwco = (BlkRwCo) { |
1351 | .blk = blk, |
1352 | .offset = offset, |
1353 | .iobuf = iobuf, |
1354 | .flags = flags, |
1355 | .ret = NOT_DONE, |
1356 | }; |
1357 | acb->bytes = bytes; |
1358 | acb->has_returned = false; |
1359 | |
1360 | co = qemu_coroutine_create(co_entry, acb); |
1361 | bdrv_coroutine_enter(blk_bs(blk), co); |
1362 | |
1363 | acb->has_returned = true; |
1364 | if (acb->rwco.ret != NOT_DONE) { |
1365 | aio_bh_schedule_oneshot(blk_get_aio_context(blk), |
1366 | blk_aio_complete_bh, acb); |
1367 | } |
1368 | |
1369 | return &acb->common; |
1370 | } |
1371 | |
1372 | static void blk_aio_read_entry(void *opaque) |
1373 | { |
1374 | BlkAioEmAIOCB *acb = opaque; |
1375 | BlkRwCo *rwco = &acb->rwco; |
1376 | QEMUIOVector *qiov = rwco->iobuf; |
1377 | |
1378 | if (rwco->blk->quiesce_counter) { |
1379 | blk_dec_in_flight(rwco->blk); |
1380 | blk_wait_while_drained(rwco->blk); |
1381 | blk_inc_in_flight(rwco->blk); |
1382 | } |
1383 | |
1384 | assert(qiov->size == acb->bytes); |
1385 | rwco->ret = blk_co_preadv(rwco->blk, rwco->offset, acb->bytes, |
1386 | qiov, rwco->flags); |
1387 | blk_aio_complete(acb); |
1388 | } |
1389 | |
1390 | static void blk_aio_write_entry(void *opaque) |
1391 | { |
1392 | BlkAioEmAIOCB *acb = opaque; |
1393 | BlkRwCo *rwco = &acb->rwco; |
1394 | QEMUIOVector *qiov = rwco->iobuf; |
1395 | |
1396 | if (rwco->blk->quiesce_counter) { |
1397 | blk_dec_in_flight(rwco->blk); |
1398 | blk_wait_while_drained(rwco->blk); |
1399 | blk_inc_in_flight(rwco->blk); |
1400 | } |
1401 | |
1402 | assert(!qiov || qiov->size == acb->bytes); |
1403 | rwco->ret = blk_co_pwritev(rwco->blk, rwco->offset, acb->bytes, |
1404 | qiov, rwco->flags); |
1405 | blk_aio_complete(acb); |
1406 | } |
1407 | |
1408 | BlockAIOCB *blk_aio_pwrite_zeroes(BlockBackend *blk, int64_t offset, |
1409 | int count, BdrvRequestFlags flags, |
1410 | BlockCompletionFunc *cb, void *opaque) |
1411 | { |
1412 | return blk_aio_prwv(blk, offset, count, NULL, blk_aio_write_entry, |
1413 | flags | BDRV_REQ_ZERO_WRITE, cb, opaque); |
1414 | } |
1415 | |
1416 | int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int count) |
1417 | { |
1418 | int ret = blk_prw(blk, offset, buf, count, blk_read_entry, 0); |
1419 | if (ret < 0) { |
1420 | return ret; |
1421 | } |
1422 | return count; |
1423 | } |
1424 | |
1425 | int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int count, |
1426 | BdrvRequestFlags flags) |
1427 | { |
1428 | int ret = blk_prw(blk, offset, (void *) buf, count, blk_write_entry, |
1429 | flags); |
1430 | if (ret < 0) { |
1431 | return ret; |
1432 | } |
1433 | return count; |
1434 | } |
1435 | |
1436 | int64_t blk_getlength(BlockBackend *blk) |
1437 | { |
1438 | if (!blk_is_available(blk)) { |
1439 | return -ENOMEDIUM; |
1440 | } |
1441 | |
1442 | return bdrv_getlength(blk_bs(blk)); |
1443 | } |
1444 | |
1445 | void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr) |
1446 | { |
1447 | if (!blk_bs(blk)) { |
1448 | *nb_sectors_ptr = 0; |
1449 | } else { |
1450 | bdrv_get_geometry(blk_bs(blk), nb_sectors_ptr); |
1451 | } |
1452 | } |
1453 | |
1454 | int64_t blk_nb_sectors(BlockBackend *blk) |
1455 | { |
1456 | if (!blk_is_available(blk)) { |
1457 | return -ENOMEDIUM; |
1458 | } |
1459 | |
1460 | return bdrv_nb_sectors(blk_bs(blk)); |
1461 | } |
1462 | |
1463 | BlockAIOCB *blk_aio_preadv(BlockBackend *blk, int64_t offset, |
1464 | QEMUIOVector *qiov, BdrvRequestFlags flags, |
1465 | BlockCompletionFunc *cb, void *opaque) |
1466 | { |
1467 | return blk_aio_prwv(blk, offset, qiov->size, qiov, |
1468 | blk_aio_read_entry, flags, cb, opaque); |
1469 | } |
1470 | |
1471 | BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t offset, |
1472 | QEMUIOVector *qiov, BdrvRequestFlags flags, |
1473 | BlockCompletionFunc *cb, void *opaque) |
1474 | { |
1475 | return blk_aio_prwv(blk, offset, qiov->size, qiov, |
1476 | blk_aio_write_entry, flags, cb, opaque); |
1477 | } |
1478 | |
1479 | static void blk_aio_flush_entry(void *opaque) |
1480 | { |
1481 | BlkAioEmAIOCB *acb = opaque; |
1482 | BlkRwCo *rwco = &acb->rwco; |
1483 | |
1484 | rwco->ret = blk_co_flush(rwco->blk); |
1485 | blk_aio_complete(acb); |
1486 | } |
1487 | |
1488 | BlockAIOCB *blk_aio_flush(BlockBackend *blk, |
1489 | BlockCompletionFunc *cb, void *opaque) |
1490 | { |
1491 | return blk_aio_prwv(blk, 0, 0, NULL, blk_aio_flush_entry, 0, cb, opaque); |
1492 | } |
1493 | |
1494 | static void blk_aio_pdiscard_entry(void *opaque) |
1495 | { |
1496 | BlkAioEmAIOCB *acb = opaque; |
1497 | BlkRwCo *rwco = &acb->rwco; |
1498 | |
1499 | rwco->ret = blk_co_pdiscard(rwco->blk, rwco->offset, acb->bytes); |
1500 | blk_aio_complete(acb); |
1501 | } |
1502 | |
1503 | BlockAIOCB *blk_aio_pdiscard(BlockBackend *blk, |
1504 | int64_t offset, int bytes, |
1505 | BlockCompletionFunc *cb, void *opaque) |
1506 | { |
1507 | return blk_aio_prwv(blk, offset, bytes, NULL, blk_aio_pdiscard_entry, 0, |
1508 | cb, opaque); |
1509 | } |
1510 | |
1511 | void blk_aio_cancel(BlockAIOCB *acb) |
1512 | { |
1513 | bdrv_aio_cancel(acb); |
1514 | } |
1515 | |
1516 | void blk_aio_cancel_async(BlockAIOCB *acb) |
1517 | { |
1518 | bdrv_aio_cancel_async(acb); |
1519 | } |
1520 | |
1521 | int blk_co_ioctl(BlockBackend *blk, unsigned long int req, void *buf) |
1522 | { |
1523 | blk_wait_while_drained(blk); |
1524 | |
1525 | if (!blk_is_available(blk)) { |
1526 | return -ENOMEDIUM; |
1527 | } |
1528 | |
1529 | return bdrv_co_ioctl(blk_bs(blk), req, buf); |
1530 | } |
1531 | |
1532 | static void blk_ioctl_entry(void *opaque) |
1533 | { |
1534 | BlkRwCo *rwco = opaque; |
1535 | QEMUIOVector *qiov = rwco->iobuf; |
1536 | |
1537 | rwco->ret = blk_co_ioctl(rwco->blk, rwco->offset, |
1538 | qiov->iov[0].iov_base); |
1539 | aio_wait_kick(); |
1540 | } |
1541 | |
1542 | int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf) |
1543 | { |
1544 | return blk_prw(blk, req, buf, 0, blk_ioctl_entry, 0); |
1545 | } |
1546 | |
1547 | static void blk_aio_ioctl_entry(void *opaque) |
1548 | { |
1549 | BlkAioEmAIOCB *acb = opaque; |
1550 | BlkRwCo *rwco = &acb->rwco; |
1551 | |
1552 | rwco->ret = blk_co_ioctl(rwco->blk, rwco->offset, rwco->iobuf); |
1553 | |
1554 | blk_aio_complete(acb); |
1555 | } |
1556 | |
1557 | BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf, |
1558 | BlockCompletionFunc *cb, void *opaque) |
1559 | { |
1560 | return blk_aio_prwv(blk, req, 0, buf, blk_aio_ioctl_entry, 0, cb, opaque); |
1561 | } |
1562 | |
1563 | int blk_co_pdiscard(BlockBackend *blk, int64_t offset, int bytes) |
1564 | { |
1565 | int ret; |
1566 | |
1567 | blk_wait_while_drained(blk); |
1568 | |
1569 | ret = blk_check_byte_request(blk, offset, bytes); |
1570 | if (ret < 0) { |
1571 | return ret; |
1572 | } |
1573 | |
1574 | return bdrv_co_pdiscard(blk->root, offset, bytes); |
1575 | } |
1576 | |
1577 | int blk_co_flush(BlockBackend *blk) |
1578 | { |
1579 | blk_wait_while_drained(blk); |
1580 | |
1581 | if (!blk_is_available(blk)) { |
1582 | return -ENOMEDIUM; |
1583 | } |
1584 | |
1585 | return bdrv_co_flush(blk_bs(blk)); |
1586 | } |
1587 | |
1588 | static void blk_flush_entry(void *opaque) |
1589 | { |
1590 | BlkRwCo *rwco = opaque; |
1591 | rwco->ret = blk_co_flush(rwco->blk); |
1592 | aio_wait_kick(); |
1593 | } |
1594 | |
1595 | int blk_flush(BlockBackend *blk) |
1596 | { |
1597 | return blk_prw(blk, 0, NULL, 0, blk_flush_entry, 0); |
1598 | } |
1599 | |
1600 | void blk_drain(BlockBackend *blk) |
1601 | { |
1602 | BlockDriverState *bs = blk_bs(blk); |
1603 | |
1604 | if (bs) { |
1605 | bdrv_drained_begin(bs); |
1606 | } |
1607 | |
1608 | /* We may have -ENOMEDIUM completions in flight */ |
1609 | AIO_WAIT_WHILE(blk_get_aio_context(blk), |
1610 | atomic_mb_read(&blk->in_flight) > 0); |
1611 | |
1612 | if (bs) { |
1613 | bdrv_drained_end(bs); |
1614 | } |
1615 | } |
1616 | |
1617 | void blk_drain_all(void) |
1618 | { |
1619 | BlockBackend *blk = NULL; |
1620 | |
1621 | bdrv_drain_all_begin(); |
1622 | |
1623 | while ((blk = blk_all_next(blk)) != NULL) { |
1624 | AioContext *ctx = blk_get_aio_context(blk); |
1625 | |
1626 | aio_context_acquire(ctx); |
1627 | |
1628 | /* We may have -ENOMEDIUM completions in flight */ |
1629 | AIO_WAIT_WHILE(ctx, atomic_mb_read(&blk->in_flight) > 0); |
1630 | |
1631 | aio_context_release(ctx); |
1632 | } |
1633 | |
1634 | bdrv_drain_all_end(); |
1635 | } |
1636 | |
1637 | void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error, |
1638 | BlockdevOnError on_write_error) |
1639 | { |
1640 | blk->on_read_error = on_read_error; |
1641 | blk->on_write_error = on_write_error; |
1642 | } |
1643 | |
1644 | BlockdevOnError blk_get_on_error(BlockBackend *blk, bool is_read) |
1645 | { |
1646 | return is_read ? blk->on_read_error : blk->on_write_error; |
1647 | } |
1648 | |
1649 | BlockErrorAction blk_get_error_action(BlockBackend *blk, bool is_read, |
1650 | int error) |
1651 | { |
1652 | BlockdevOnError on_err = blk_get_on_error(blk, is_read); |
1653 | |
1654 | switch (on_err) { |
1655 | case BLOCKDEV_ON_ERROR_ENOSPC: |
1656 | return (error == ENOSPC) ? |
1657 | BLOCK_ERROR_ACTION_STOP : BLOCK_ERROR_ACTION_REPORT; |
1658 | case BLOCKDEV_ON_ERROR_STOP: |
1659 | return BLOCK_ERROR_ACTION_STOP; |
1660 | case BLOCKDEV_ON_ERROR_REPORT: |
1661 | return BLOCK_ERROR_ACTION_REPORT; |
1662 | case BLOCKDEV_ON_ERROR_IGNORE: |
1663 | return BLOCK_ERROR_ACTION_IGNORE; |
1664 | case BLOCKDEV_ON_ERROR_AUTO: |
1665 | default: |
1666 | abort(); |
1667 | } |
1668 | } |
1669 | |
1670 | static void send_qmp_error_event(BlockBackend *blk, |
1671 | BlockErrorAction action, |
1672 | bool is_read, int error) |
1673 | { |
1674 | IoOperationType optype; |
1675 | BlockDriverState *bs = blk_bs(blk); |
1676 | |
1677 | optype = is_read ? IO_OPERATION_TYPE_READ : IO_OPERATION_TYPE_WRITE; |
1678 | qapi_event_send_block_io_error(blk_name(blk), !!bs, |
1679 | bs ? bdrv_get_node_name(bs) : NULL, optype, |
1680 | action, blk_iostatus_is_enabled(blk), |
1681 | error == ENOSPC, strerror(error)); |
1682 | } |
1683 | |
1684 | /* This is done by device models because, while the block layer knows |
1685 | * about the error, it does not know whether an operation comes from |
1686 | * the device or the block layer (from a job, for example). |
1687 | */ |
1688 | void blk_error_action(BlockBackend *blk, BlockErrorAction action, |
1689 | bool is_read, int error) |
1690 | { |
1691 | assert(error >= 0); |
1692 | |
1693 | if (action == BLOCK_ERROR_ACTION_STOP) { |
1694 | /* First set the iostatus, so that "info block" returns an iostatus |
1695 | * that matches the events raised so far (an additional error iostatus |
1696 | * is fine, but not a lost one). |
1697 | */ |
1698 | blk_iostatus_set_err(blk, error); |
1699 | |
1700 | /* Then raise the request to stop the VM and the event. |
1701 | * qemu_system_vmstop_request_prepare has two effects. First, |
1702 | * it ensures that the STOP event always comes after the |
1703 | * BLOCK_IO_ERROR event. Second, it ensures that even if management |
1704 | * can observe the STOP event and do a "cont" before the STOP |
1705 | * event is issued, the VM will not stop. In this case, vm_start() |
1706 | * also ensures that the STOP/RESUME pair of events is emitted. |
1707 | */ |
1708 | qemu_system_vmstop_request_prepare(); |
1709 | send_qmp_error_event(blk, action, is_read, error); |
1710 | qemu_system_vmstop_request(RUN_STATE_IO_ERROR); |
1711 | } else { |
1712 | send_qmp_error_event(blk, action, is_read, error); |
1713 | } |
1714 | } |
1715 | |
1716 | bool blk_is_read_only(BlockBackend *blk) |
1717 | { |
1718 | BlockDriverState *bs = blk_bs(blk); |
1719 | |
1720 | if (bs) { |
1721 | return bdrv_is_read_only(bs); |
1722 | } else { |
1723 | return blk->root_state.read_only; |
1724 | } |
1725 | } |
1726 | |
1727 | bool blk_is_sg(BlockBackend *blk) |
1728 | { |
1729 | BlockDriverState *bs = blk_bs(blk); |
1730 | |
1731 | if (!bs) { |
1732 | return false; |
1733 | } |
1734 | |
1735 | return bdrv_is_sg(bs); |
1736 | } |
1737 | |
1738 | bool blk_enable_write_cache(BlockBackend *blk) |
1739 | { |
1740 | return blk->enable_write_cache; |
1741 | } |
1742 | |
1743 | void blk_set_enable_write_cache(BlockBackend *blk, bool wce) |
1744 | { |
1745 | blk->enable_write_cache = wce; |
1746 | } |
1747 | |
1748 | void blk_invalidate_cache(BlockBackend *blk, Error **errp) |
1749 | { |
1750 | BlockDriverState *bs = blk_bs(blk); |
1751 | |
1752 | if (!bs) { |
1753 | error_setg(errp, "Device '%s' has no medium" , blk->name); |
1754 | return; |
1755 | } |
1756 | |
1757 | bdrv_invalidate_cache(bs, errp); |
1758 | } |
1759 | |
1760 | bool blk_is_inserted(BlockBackend *blk) |
1761 | { |
1762 | BlockDriverState *bs = blk_bs(blk); |
1763 | |
1764 | return bs && bdrv_is_inserted(bs); |
1765 | } |
1766 | |
1767 | bool blk_is_available(BlockBackend *blk) |
1768 | { |
1769 | return blk_is_inserted(blk) && !blk_dev_is_tray_open(blk); |
1770 | } |
1771 | |
1772 | void blk_lock_medium(BlockBackend *blk, bool locked) |
1773 | { |
1774 | BlockDriverState *bs = blk_bs(blk); |
1775 | |
1776 | if (bs) { |
1777 | bdrv_lock_medium(bs, locked); |
1778 | } |
1779 | } |
1780 | |
1781 | void blk_eject(BlockBackend *blk, bool eject_flag) |
1782 | { |
1783 | BlockDriverState *bs = blk_bs(blk); |
1784 | char *id; |
1785 | |
1786 | if (bs) { |
1787 | bdrv_eject(bs, eject_flag); |
1788 | } |
1789 | |
1790 | /* Whether or not we ejected on the backend, |
1791 | * the frontend experienced a tray event. */ |
1792 | id = blk_get_attached_dev_id(blk); |
1793 | qapi_event_send_device_tray_moved(blk_name(blk), id, |
1794 | eject_flag); |
1795 | g_free(id); |
1796 | } |
1797 | |
1798 | int blk_get_flags(BlockBackend *blk) |
1799 | { |
1800 | BlockDriverState *bs = blk_bs(blk); |
1801 | |
1802 | if (bs) { |
1803 | return bdrv_get_flags(bs); |
1804 | } else { |
1805 | return blk->root_state.open_flags; |
1806 | } |
1807 | } |
1808 | |
1809 | /* Returns the minimum request alignment, in bytes; guaranteed nonzero */ |
1810 | uint32_t blk_get_request_alignment(BlockBackend *blk) |
1811 | { |
1812 | BlockDriverState *bs = blk_bs(blk); |
1813 | return bs ? bs->bl.request_alignment : BDRV_SECTOR_SIZE; |
1814 | } |
1815 | |
1816 | /* Returns the maximum transfer length, in bytes; guaranteed nonzero */ |
1817 | uint32_t blk_get_max_transfer(BlockBackend *blk) |
1818 | { |
1819 | BlockDriverState *bs = blk_bs(blk); |
1820 | uint32_t max = 0; |
1821 | |
1822 | if (bs) { |
1823 | max = bs->bl.max_transfer; |
1824 | } |
1825 | return MIN_NON_ZERO(max, INT_MAX); |
1826 | } |
1827 | |
1828 | int blk_get_max_iov(BlockBackend *blk) |
1829 | { |
1830 | return blk->root->bs->bl.max_iov; |
1831 | } |
1832 | |
1833 | void blk_set_guest_block_size(BlockBackend *blk, int align) |
1834 | { |
1835 | blk->guest_block_size = align; |
1836 | } |
1837 | |
1838 | void *blk_try_blockalign(BlockBackend *blk, size_t size) |
1839 | { |
1840 | return qemu_try_blockalign(blk ? blk_bs(blk) : NULL, size); |
1841 | } |
1842 | |
1843 | void *blk_blockalign(BlockBackend *blk, size_t size) |
1844 | { |
1845 | return qemu_blockalign(blk ? blk_bs(blk) : NULL, size); |
1846 | } |
1847 | |
1848 | bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp) |
1849 | { |
1850 | BlockDriverState *bs = blk_bs(blk); |
1851 | |
1852 | if (!bs) { |
1853 | return false; |
1854 | } |
1855 | |
1856 | return bdrv_op_is_blocked(bs, op, errp); |
1857 | } |
1858 | |
1859 | void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason) |
1860 | { |
1861 | BlockDriverState *bs = blk_bs(blk); |
1862 | |
1863 | if (bs) { |
1864 | bdrv_op_unblock(bs, op, reason); |
1865 | } |
1866 | } |
1867 | |
1868 | void blk_op_block_all(BlockBackend *blk, Error *reason) |
1869 | { |
1870 | BlockDriverState *bs = blk_bs(blk); |
1871 | |
1872 | if (bs) { |
1873 | bdrv_op_block_all(bs, reason); |
1874 | } |
1875 | } |
1876 | |
1877 | void blk_op_unblock_all(BlockBackend *blk, Error *reason) |
1878 | { |
1879 | BlockDriverState *bs = blk_bs(blk); |
1880 | |
1881 | if (bs) { |
1882 | bdrv_op_unblock_all(bs, reason); |
1883 | } |
1884 | } |
1885 | |
1886 | AioContext *blk_get_aio_context(BlockBackend *blk) |
1887 | { |
1888 | BlockDriverState *bs = blk_bs(blk); |
1889 | |
1890 | if (bs) { |
1891 | AioContext *ctx = bdrv_get_aio_context(blk_bs(blk)); |
1892 | assert(ctx == blk->ctx); |
1893 | } |
1894 | |
1895 | return blk->ctx; |
1896 | } |
1897 | |
1898 | static AioContext *blk_aiocb_get_aio_context(BlockAIOCB *acb) |
1899 | { |
1900 | BlockBackendAIOCB *blk_acb = DO_UPCAST(BlockBackendAIOCB, common, acb); |
1901 | return blk_get_aio_context(blk_acb->blk); |
1902 | } |
1903 | |
1904 | static int blk_do_set_aio_context(BlockBackend *blk, AioContext *new_context, |
1905 | bool update_root_node, Error **errp) |
1906 | { |
1907 | BlockDriverState *bs = blk_bs(blk); |
1908 | ThrottleGroupMember *tgm = &blk->public.throttle_group_member; |
1909 | int ret; |
1910 | |
1911 | if (bs) { |
1912 | if (update_root_node) { |
1913 | ret = bdrv_child_try_set_aio_context(bs, new_context, blk->root, |
1914 | errp); |
1915 | if (ret < 0) { |
1916 | return ret; |
1917 | } |
1918 | } |
1919 | if (tgm->throttle_state) { |
1920 | bdrv_drained_begin(bs); |
1921 | throttle_group_detach_aio_context(tgm); |
1922 | throttle_group_attach_aio_context(tgm, new_context); |
1923 | bdrv_drained_end(bs); |
1924 | } |
1925 | } |
1926 | |
1927 | blk->ctx = new_context; |
1928 | return 0; |
1929 | } |
1930 | |
1931 | int blk_set_aio_context(BlockBackend *blk, AioContext *new_context, |
1932 | Error **errp) |
1933 | { |
1934 | return blk_do_set_aio_context(blk, new_context, true, errp); |
1935 | } |
1936 | |
1937 | static bool blk_root_can_set_aio_ctx(BdrvChild *child, AioContext *ctx, |
1938 | GSList **ignore, Error **errp) |
1939 | { |
1940 | BlockBackend *blk = child->opaque; |
1941 | |
1942 | if (blk->allow_aio_context_change) { |
1943 | return true; |
1944 | } |
1945 | |
1946 | /* Only manually created BlockBackends that are not attached to anything |
1947 | * can change their AioContext without updating their user. */ |
1948 | if (!blk->name || blk->dev) { |
1949 | /* TODO Add BB name/QOM path */ |
1950 | error_setg(errp, "Cannot change iothread of active block backend" ); |
1951 | return false; |
1952 | } |
1953 | |
1954 | return true; |
1955 | } |
1956 | |
1957 | static void blk_root_set_aio_ctx(BdrvChild *child, AioContext *ctx, |
1958 | GSList **ignore) |
1959 | { |
1960 | BlockBackend *blk = child->opaque; |
1961 | blk_do_set_aio_context(blk, ctx, false, &error_abort); |
1962 | } |
1963 | |
1964 | void blk_add_aio_context_notifier(BlockBackend *blk, |
1965 | void (*attached_aio_context)(AioContext *new_context, void *opaque), |
1966 | void (*detach_aio_context)(void *opaque), void *opaque) |
1967 | { |
1968 | BlockBackendAioNotifier *notifier; |
1969 | BlockDriverState *bs = blk_bs(blk); |
1970 | |
1971 | notifier = g_new(BlockBackendAioNotifier, 1); |
1972 | notifier->attached_aio_context = attached_aio_context; |
1973 | notifier->detach_aio_context = detach_aio_context; |
1974 | notifier->opaque = opaque; |
1975 | QLIST_INSERT_HEAD(&blk->aio_notifiers, notifier, list); |
1976 | |
1977 | if (bs) { |
1978 | bdrv_add_aio_context_notifier(bs, attached_aio_context, |
1979 | detach_aio_context, opaque); |
1980 | } |
1981 | } |
1982 | |
1983 | void blk_remove_aio_context_notifier(BlockBackend *blk, |
1984 | void (*attached_aio_context)(AioContext *, |
1985 | void *), |
1986 | void (*detach_aio_context)(void *), |
1987 | void *opaque) |
1988 | { |
1989 | BlockBackendAioNotifier *notifier; |
1990 | BlockDriverState *bs = blk_bs(blk); |
1991 | |
1992 | if (bs) { |
1993 | bdrv_remove_aio_context_notifier(bs, attached_aio_context, |
1994 | detach_aio_context, opaque); |
1995 | } |
1996 | |
1997 | QLIST_FOREACH(notifier, &blk->aio_notifiers, list) { |
1998 | if (notifier->attached_aio_context == attached_aio_context && |
1999 | notifier->detach_aio_context == detach_aio_context && |
2000 | notifier->opaque == opaque) { |
2001 | QLIST_REMOVE(notifier, list); |
2002 | g_free(notifier); |
2003 | return; |
2004 | } |
2005 | } |
2006 | |
2007 | abort(); |
2008 | } |
2009 | |
2010 | void blk_add_remove_bs_notifier(BlockBackend *blk, Notifier *notify) |
2011 | { |
2012 | notifier_list_add(&blk->remove_bs_notifiers, notify); |
2013 | } |
2014 | |
2015 | void blk_add_insert_bs_notifier(BlockBackend *blk, Notifier *notify) |
2016 | { |
2017 | notifier_list_add(&blk->insert_bs_notifiers, notify); |
2018 | } |
2019 | |
2020 | void blk_io_plug(BlockBackend *blk) |
2021 | { |
2022 | BlockDriverState *bs = blk_bs(blk); |
2023 | |
2024 | if (bs) { |
2025 | bdrv_io_plug(bs); |
2026 | } |
2027 | } |
2028 | |
2029 | void blk_io_unplug(BlockBackend *blk) |
2030 | { |
2031 | BlockDriverState *bs = blk_bs(blk); |
2032 | |
2033 | if (bs) { |
2034 | bdrv_io_unplug(bs); |
2035 | } |
2036 | } |
2037 | |
2038 | BlockAcctStats *blk_get_stats(BlockBackend *blk) |
2039 | { |
2040 | return &blk->stats; |
2041 | } |
2042 | |
2043 | void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk, |
2044 | BlockCompletionFunc *cb, void *opaque) |
2045 | { |
2046 | return qemu_aio_get(aiocb_info, blk_bs(blk), cb, opaque); |
2047 | } |
2048 | |
2049 | int coroutine_fn blk_co_pwrite_zeroes(BlockBackend *blk, int64_t offset, |
2050 | int bytes, BdrvRequestFlags flags) |
2051 | { |
2052 | return blk_co_pwritev(blk, offset, bytes, NULL, |
2053 | flags | BDRV_REQ_ZERO_WRITE); |
2054 | } |
2055 | |
2056 | int blk_pwrite_compressed(BlockBackend *blk, int64_t offset, const void *buf, |
2057 | int count) |
2058 | { |
2059 | return blk_prw(blk, offset, (void *) buf, count, blk_write_entry, |
2060 | BDRV_REQ_WRITE_COMPRESSED); |
2061 | } |
2062 | |
2063 | int blk_truncate(BlockBackend *blk, int64_t offset, PreallocMode prealloc, |
2064 | Error **errp) |
2065 | { |
2066 | if (!blk_is_available(blk)) { |
2067 | error_setg(errp, "No medium inserted" ); |
2068 | return -ENOMEDIUM; |
2069 | } |
2070 | |
2071 | return bdrv_truncate(blk->root, offset, prealloc, errp); |
2072 | } |
2073 | |
2074 | static void blk_pdiscard_entry(void *opaque) |
2075 | { |
2076 | BlkRwCo *rwco = opaque; |
2077 | QEMUIOVector *qiov = rwco->iobuf; |
2078 | |
2079 | rwco->ret = blk_co_pdiscard(rwco->blk, rwco->offset, qiov->size); |
2080 | aio_wait_kick(); |
2081 | } |
2082 | |
2083 | int blk_pdiscard(BlockBackend *blk, int64_t offset, int bytes) |
2084 | { |
2085 | return blk_prw(blk, offset, NULL, bytes, blk_pdiscard_entry, 0); |
2086 | } |
2087 | |
2088 | int blk_save_vmstate(BlockBackend *blk, const uint8_t *buf, |
2089 | int64_t pos, int size) |
2090 | { |
2091 | int ret; |
2092 | |
2093 | if (!blk_is_available(blk)) { |
2094 | return -ENOMEDIUM; |
2095 | } |
2096 | |
2097 | ret = bdrv_save_vmstate(blk_bs(blk), buf, pos, size); |
2098 | if (ret < 0) { |
2099 | return ret; |
2100 | } |
2101 | |
2102 | if (ret == size && !blk->enable_write_cache) { |
2103 | ret = bdrv_flush(blk_bs(blk)); |
2104 | } |
2105 | |
2106 | return ret < 0 ? ret : size; |
2107 | } |
2108 | |
2109 | int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size) |
2110 | { |
2111 | if (!blk_is_available(blk)) { |
2112 | return -ENOMEDIUM; |
2113 | } |
2114 | |
2115 | return bdrv_load_vmstate(blk_bs(blk), buf, pos, size); |
2116 | } |
2117 | |
2118 | int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz) |
2119 | { |
2120 | if (!blk_is_available(blk)) { |
2121 | return -ENOMEDIUM; |
2122 | } |
2123 | |
2124 | return bdrv_probe_blocksizes(blk_bs(blk), bsz); |
2125 | } |
2126 | |
2127 | int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo) |
2128 | { |
2129 | if (!blk_is_available(blk)) { |
2130 | return -ENOMEDIUM; |
2131 | } |
2132 | |
2133 | return bdrv_probe_geometry(blk_bs(blk), geo); |
2134 | } |
2135 | |
2136 | /* |
2137 | * Updates the BlockBackendRootState object with data from the currently |
2138 | * attached BlockDriverState. |
2139 | */ |
2140 | void blk_update_root_state(BlockBackend *blk) |
2141 | { |
2142 | assert(blk->root); |
2143 | |
2144 | blk->root_state.open_flags = blk->root->bs->open_flags; |
2145 | blk->root_state.read_only = blk->root->bs->read_only; |
2146 | blk->root_state.detect_zeroes = blk->root->bs->detect_zeroes; |
2147 | } |
2148 | |
2149 | /* |
2150 | * Returns the detect-zeroes setting to be used for bdrv_open() of a |
2151 | * BlockDriverState which is supposed to inherit the root state. |
2152 | */ |
2153 | bool blk_get_detect_zeroes_from_root_state(BlockBackend *blk) |
2154 | { |
2155 | return blk->root_state.detect_zeroes; |
2156 | } |
2157 | |
2158 | /* |
2159 | * Returns the flags to be used for bdrv_open() of a BlockDriverState which is |
2160 | * supposed to inherit the root state. |
2161 | */ |
2162 | int blk_get_open_flags_from_root_state(BlockBackend *blk) |
2163 | { |
2164 | int bs_flags; |
2165 | |
2166 | bs_flags = blk->root_state.read_only ? 0 : BDRV_O_RDWR; |
2167 | bs_flags |= blk->root_state.open_flags & ~BDRV_O_RDWR; |
2168 | |
2169 | return bs_flags; |
2170 | } |
2171 | |
2172 | BlockBackendRootState *blk_get_root_state(BlockBackend *blk) |
2173 | { |
2174 | return &blk->root_state; |
2175 | } |
2176 | |
2177 | int blk_commit_all(void) |
2178 | { |
2179 | BlockBackend *blk = NULL; |
2180 | |
2181 | while ((blk = blk_all_next(blk)) != NULL) { |
2182 | AioContext *aio_context = blk_get_aio_context(blk); |
2183 | |
2184 | aio_context_acquire(aio_context); |
2185 | if (blk_is_inserted(blk) && blk->root->bs->backing) { |
2186 | int ret = bdrv_commit(blk->root->bs); |
2187 | if (ret < 0) { |
2188 | aio_context_release(aio_context); |
2189 | return ret; |
2190 | } |
2191 | } |
2192 | aio_context_release(aio_context); |
2193 | } |
2194 | return 0; |
2195 | } |
2196 | |
2197 | |
2198 | /* throttling disk I/O limits */ |
2199 | void blk_set_io_limits(BlockBackend *blk, ThrottleConfig *cfg) |
2200 | { |
2201 | throttle_group_config(&blk->public.throttle_group_member, cfg); |
2202 | } |
2203 | |
2204 | void blk_io_limits_disable(BlockBackend *blk) |
2205 | { |
2206 | BlockDriverState *bs = blk_bs(blk); |
2207 | ThrottleGroupMember *tgm = &blk->public.throttle_group_member; |
2208 | assert(tgm->throttle_state); |
2209 | if (bs) { |
2210 | bdrv_drained_begin(bs); |
2211 | } |
2212 | throttle_group_unregister_tgm(tgm); |
2213 | if (bs) { |
2214 | bdrv_drained_end(bs); |
2215 | } |
2216 | } |
2217 | |
2218 | /* should be called before blk_set_io_limits if a limit is set */ |
2219 | void blk_io_limits_enable(BlockBackend *blk, const char *group) |
2220 | { |
2221 | assert(!blk->public.throttle_group_member.throttle_state); |
2222 | throttle_group_register_tgm(&blk->public.throttle_group_member, |
2223 | group, blk_get_aio_context(blk)); |
2224 | } |
2225 | |
2226 | void blk_io_limits_update_group(BlockBackend *blk, const char *group) |
2227 | { |
2228 | /* this BB is not part of any group */ |
2229 | if (!blk->public.throttle_group_member.throttle_state) { |
2230 | return; |
2231 | } |
2232 | |
2233 | /* this BB is a part of the same group than the one we want */ |
2234 | if (!g_strcmp0(throttle_group_get_name(&blk->public.throttle_group_member), |
2235 | group)) { |
2236 | return; |
2237 | } |
2238 | |
2239 | /* need to change the group this bs belong to */ |
2240 | blk_io_limits_disable(blk); |
2241 | blk_io_limits_enable(blk, group); |
2242 | } |
2243 | |
2244 | static void blk_root_drained_begin(BdrvChild *child) |
2245 | { |
2246 | BlockBackend *blk = child->opaque; |
2247 | |
2248 | if (++blk->quiesce_counter == 1) { |
2249 | if (blk->dev_ops && blk->dev_ops->drained_begin) { |
2250 | blk->dev_ops->drained_begin(blk->dev_opaque); |
2251 | } |
2252 | } |
2253 | |
2254 | /* Note that blk->root may not be accessible here yet if we are just |
2255 | * attaching to a BlockDriverState that is drained. Use child instead. */ |
2256 | |
2257 | if (atomic_fetch_inc(&blk->public.throttle_group_member.io_limits_disabled) == 0) { |
2258 | throttle_group_restart_tgm(&blk->public.throttle_group_member); |
2259 | } |
2260 | } |
2261 | |
2262 | static bool blk_root_drained_poll(BdrvChild *child) |
2263 | { |
2264 | BlockBackend *blk = child->opaque; |
2265 | assert(blk->quiesce_counter); |
2266 | return !!blk->in_flight; |
2267 | } |
2268 | |
2269 | static void blk_root_drained_end(BdrvChild *child, int *drained_end_counter) |
2270 | { |
2271 | BlockBackend *blk = child->opaque; |
2272 | assert(blk->quiesce_counter); |
2273 | |
2274 | assert(blk->public.throttle_group_member.io_limits_disabled); |
2275 | atomic_dec(&blk->public.throttle_group_member.io_limits_disabled); |
2276 | |
2277 | if (--blk->quiesce_counter == 0) { |
2278 | if (blk->dev_ops && blk->dev_ops->drained_end) { |
2279 | blk->dev_ops->drained_end(blk->dev_opaque); |
2280 | } |
2281 | while (qemu_co_enter_next(&blk->queued_requests, NULL)) { |
2282 | /* Resume all queued requests */ |
2283 | } |
2284 | } |
2285 | } |
2286 | |
2287 | void blk_register_buf(BlockBackend *blk, void *host, size_t size) |
2288 | { |
2289 | bdrv_register_buf(blk_bs(blk), host, size); |
2290 | } |
2291 | |
2292 | void blk_unregister_buf(BlockBackend *blk, void *host) |
2293 | { |
2294 | bdrv_unregister_buf(blk_bs(blk), host); |
2295 | } |
2296 | |
2297 | int coroutine_fn blk_co_copy_range(BlockBackend *blk_in, int64_t off_in, |
2298 | BlockBackend *blk_out, int64_t off_out, |
2299 | int bytes, BdrvRequestFlags read_flags, |
2300 | BdrvRequestFlags write_flags) |
2301 | { |
2302 | int r; |
2303 | r = blk_check_byte_request(blk_in, off_in, bytes); |
2304 | if (r) { |
2305 | return r; |
2306 | } |
2307 | r = blk_check_byte_request(blk_out, off_out, bytes); |
2308 | if (r) { |
2309 | return r; |
2310 | } |
2311 | return bdrv_co_copy_range(blk_in->root, off_in, |
2312 | blk_out->root, off_out, |
2313 | bytes, read_flags, write_flags); |
2314 | } |
2315 | |
2316 | const BdrvChild *blk_root(BlockBackend *blk) |
2317 | { |
2318 | return blk->root; |
2319 | } |
2320 | |