aboutsummaryrefslogtreecommitdiff
path: root/block/block-backend.c
blob: ef16d7356a87fb433390d2e9f539ebda637782a4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
/*
 * QEMU Block backends
 *
 * Copyright (C) 2014 Red Hat, Inc.
 *
 * Authors:
 *  Markus Armbruster <armbru@redhat.com>,
 *
 * This work is licensed under the terms of the GNU LGPL, version 2.1
 * or later.  See the COPYING.LIB file in the top-level directory.
 */

#include "sysemu/block-backend.h"
#include "block/block_int.h"
#include "sysemu/blockdev.h"
#include "qapi-event.h"

/* Number of coroutines to reserve per attached device model */
#define COROUTINE_POOL_RESERVATION 64

struct BlockBackend {
    char *name;
    int refcnt;
    BlockDriverState *bs;
    DriveInfo *legacy_dinfo;    /* null unless created by drive_new() */
    QTAILQ_ENTRY(BlockBackend) link; /* for blk_backends */

    void *dev;                  /* attached device model, if any */
    /* TODO change to DeviceState when all users are qdevified */
    const BlockDevOps *dev_ops;
    void *dev_opaque;
};

static void drive_info_del(DriveInfo *dinfo);

/* All the BlockBackends (except for hidden ones) */
static QTAILQ_HEAD(, BlockBackend) blk_backends =
    QTAILQ_HEAD_INITIALIZER(blk_backends);

/*
 * Create a new BlockBackend with @name, with a reference count of one.
 * @name must not be null or empty.
 * Fail if a BlockBackend with this name already exists.
 * Store an error through @errp on failure, unless it's null.
 * Return the new BlockBackend on success, null on failure.
 */
BlockBackend *blk_new(const char *name, Error **errp)
{
    BlockBackend *blk;

    assert(name && name[0]);
    if (!id_wellformed(name)) {
        error_setg(errp, "Invalid device name");
        return NULL;
    }
    if (blk_by_name(name)) {
        error_setg(errp, "Device with id '%s' already exists", name);
        return NULL;
    }
    if (bdrv_find_node(name)) {
        error_setg(errp,
                   "Device name '%s' conflicts with an existing node name",
                   name);
        return NULL;
    }

    blk = g_new0(BlockBackend, 1);
    blk->name = g_strdup(name);
    blk->refcnt = 1;
    QTAILQ_INSERT_TAIL(&blk_backends, blk, link);
    return blk;
}

/*
 * Create a new BlockBackend with a new BlockDriverState attached.
 * Otherwise just like blk_new(), which see.
 */
BlockBackend *blk_new_with_bs(const char *name, Error **errp)
{
    BlockBackend *blk;
    BlockDriverState *bs;

    blk = blk_new(name, errp);
    if (!blk) {
        return NULL;
    }

    bs = bdrv_new_root();
    blk->bs = bs;
    bs->blk = blk;
    return blk;
}

static void blk_delete(BlockBackend *blk)
{
    assert(!blk->refcnt);
    assert(!blk->dev);
    if (blk->bs) {
        assert(blk->bs->blk == blk);
        blk->bs->blk = NULL;
        bdrv_unref(blk->bs);
        blk->bs = NULL;
    }
    /* Avoid double-remove after blk_hide_on_behalf_of_do_drive_del() */
    if (blk->name[0]) {
        QTAILQ_REMOVE(&blk_backends, blk, link);
    }
    g_free(blk->name);
    drive_info_del(blk->legacy_dinfo);
    g_free(blk);
}

static void drive_info_del(DriveInfo *dinfo)
{
    if (!dinfo) {
        return;
    }
    qemu_opts_del(dinfo->opts);
    g_free(dinfo->serial);
    g_free(dinfo);
}

/*
 * Increment @blk's reference count.
 * @blk must not be null.
 */
void blk_ref(BlockBackend *blk)
{
    blk->refcnt++;
}

/*
 * Decrement @blk's reference count.
 * If this drops it to zero, destroy @blk.
 * For convenience, do nothing if @blk is null.
 */
void blk_unref(BlockBackend *blk)
{
    if (blk) {
        assert(blk->refcnt > 0);
        if (!--blk->refcnt) {
            blk_delete(blk);
        }
    }
}

/*
 * Return the BlockBackend after @blk.
 * If @blk is null, return the first one.
 * Else, return @blk's next sibling, which may be null.
 *
 * To iterate over all BlockBackends, do
 * for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
 *     ...
 * }
 */
BlockBackend *blk_next(BlockBackend *blk)
{
    return blk ? QTAILQ_NEXT(blk, link) : QTAILQ_FIRST(&blk_backends);
}

/*
 * Return @blk's name, a non-null string.
 * Wart: the name is empty iff @blk has been hidden with
 * blk_hide_on_behalf_of_do_drive_del().
 */
const char *blk_name(BlockBackend *blk)
{
    return blk->name;
}

/*
 * Return the BlockBackend with name @name if it exists, else null.
 * @name must not be null.
 */
BlockBackend *blk_by_name(const char *name)
{
    BlockBackend *blk;

    assert(name);
    QTAILQ_FOREACH(blk, &blk_backends, link) {
        if (!strcmp(name, blk->name)) {
            return blk;
        }
    }
    return NULL;
}

/*
 * Return the BlockDriverState attached to @blk if any, else null.
 */
BlockDriverState *blk_bs(BlockBackend *blk)
{
    return blk->bs;
}

/*
 * Return @blk's DriveInfo if any, else null.
 */
DriveInfo *blk_legacy_dinfo(BlockBackend *blk)
{
    return blk->legacy_dinfo;
}

/*
 * Set @blk's DriveInfo to @dinfo, and return it.
 * @blk must not have a DriveInfo set already.
 * No other BlockBackend may have the same DriveInfo set.
 */
DriveInfo *blk_set_legacy_dinfo(BlockBackend *blk, DriveInfo *dinfo)
{
    assert(!blk->legacy_dinfo);
    return blk->legacy_dinfo = dinfo;
}

/*
 * Return the BlockBackend with DriveInfo @dinfo.
 * It must exist.
 */
BlockBackend *blk_by_legacy_dinfo(DriveInfo *dinfo)
{
    BlockBackend *blk;

    QTAILQ_FOREACH(blk, &blk_backends, link) {
        if (blk->legacy_dinfo == dinfo) {
            return blk;
        }
    }
    abort();
}

/*
 * Hide @blk.
 * @blk must not have been hidden already.
 * Make attached BlockDriverState, if any, anonymous.
 * Once hidden, @blk is invisible to all functions that don't receive
 * it as argument.  For example, blk_by_name() won't return it.
 * Strictly for use by do_drive_del().
 * TODO get rid of it!
 */
void blk_hide_on_behalf_of_do_drive_del(BlockBackend *blk)
{
    QTAILQ_REMOVE(&blk_backends, blk, link);
    blk->name[0] = 0;
    if (blk->bs) {
        bdrv_make_anon(blk->bs);
    }
}

/*
 * Attach device model @dev to @blk.
 * Return 0 on success, -EBUSY when a device model is attached already.
 */
int blk_attach_dev(BlockBackend *blk, void *dev)
/* TODO change to DeviceState *dev when all users are qdevified */
{
    if (blk->dev) {
        return -EBUSY;
    }
    blk_ref(blk);
    blk->dev = dev;
    bdrv_iostatus_reset(blk->bs);

    /* We're expecting I/O from the device so bump up coroutine pool size */
    qemu_coroutine_adjust_pool_size(COROUTINE_POOL_RESERVATION);
    return 0;
}

/*
 * Attach device model @dev to @blk.
 * @blk must not have a device model attached already.
 * TODO qdevified devices don't use this, remove when devices are qdevified
 */
void blk_attach_dev_nofail(BlockBackend *blk, void *dev)
{
    if (blk_attach_dev(blk, dev) < 0) {
        abort();
    }
}

/*
 * Detach device model @dev from @blk.
 * @dev must be currently attached to @blk.
 */
void blk_detach_dev(BlockBackend *blk, void *dev)
/* TODO change to DeviceState *dev when all users are qdevified */
{
    assert(blk->dev == dev);
    blk->dev = NULL;
    blk->dev_ops = NULL;
    blk->dev_opaque = NULL;
    bdrv_set_guest_block_size(blk->bs, 512);
    qemu_coroutine_adjust_pool_size(-COROUTINE_POOL_RESERVATION);
    blk_unref(blk);
}

/*
 * Return the device model attached to @blk if any, else null.
 */
void *blk_get_attached_dev(BlockBackend *blk)
/* TODO change to return DeviceState * when all users are qdevified */
{
    return blk->dev;
}

/*
 * Set @blk's device model callbacks to @ops.
 * @opaque is the opaque argument to pass to the callbacks.
 * This is for use by device models.
 */
void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops,
                     void *opaque)
{
    blk->dev_ops = ops;
    blk->dev_opaque = opaque;
}

/*
 * Notify @blk's attached device model of media change.
 * If @load is true, notify of media load.
 * Else, notify of media eject.
 * Also send DEVICE_TRAY_MOVED events as appropriate.
 */
void blk_dev_change_media_cb(BlockBackend *blk, bool load)
{
    if (blk->dev_ops && blk->dev_ops->change_media_cb) {
        bool tray_was_closed = !blk_dev_is_tray_open(blk);

        blk->dev_ops->change_media_cb(blk->dev_opaque, load);
        if (tray_was_closed) {
            /* tray open */
            qapi_event_send_device_tray_moved(blk_name(blk),
                                              true, &error_abort);
        }
        if (load) {
            /* tray close */
            qapi_event_send_device_tray_moved(blk_name(blk),
                                              false, &error_abort);
        }
    }
}

/*
 * Does @blk's attached device model have removable media?
 * %true if no device model is attached.
 */
bool blk_dev_has_removable_media(BlockBackend *blk)
{
    return !blk->dev || (blk->dev_ops && blk->dev_ops->change_media_cb);
}

/*
 * Notify @blk's attached device model of a media eject request.
 * If @force is true, the medium is about to be yanked out forcefully.
 */
void blk_dev_eject_request(BlockBackend *blk, bool force)
{
    if (blk->dev_ops && blk->dev_ops->eject_request_cb) {
        blk->dev_ops->eject_request_cb(blk->dev_opaque, force);
    }
}

/*
 * Does @blk's attached device model have a tray, and is it open?
 */
bool blk_dev_is_tray_open(BlockBackend *blk)
{
    if (blk->dev_ops && blk->dev_ops->is_tray_open) {
        return blk->dev_ops->is_tray_open(blk->dev_opaque);
    }
    return false;
}

/*
 * Does @blk's attached device model have the medium locked?
 * %false if the device model has no such lock.
 */
bool blk_dev_is_medium_locked(BlockBackend *blk)
{
    if (blk->dev_ops && blk->dev_ops->is_medium_locked) {
        return blk->dev_ops->is_medium_locked(blk->dev_opaque);
    }
    return false;
}

/*
 * Notify @blk's attached device model of a backend size change.
 */
void blk_dev_resize_cb(BlockBackend *blk)
{
    if (blk->dev_ops && blk->dev_ops->resize_cb) {
        blk->dev_ops->resize_cb(blk->dev_opaque);
    }
}

void blk_iostatus_enable(BlockBackend *blk)
{
    bdrv_iostatus_enable(blk->bs);
}

int blk_read(BlockBackend *blk, int64_t sector_num, uint8_t *buf,
             int nb_sectors)
{
    return bdrv_read(blk->bs, sector_num, buf, nb_sectors);
}

int blk_read_unthrottled(BlockBackend *blk, int64_t sector_num, uint8_t *buf,
                         int nb_sectors)
{
    return bdrv_read_unthrottled(blk->bs, sector_num, buf, nb_sectors);
}

int blk_write(BlockBackend *blk, int64_t sector_num, const uint8_t *buf,
              int nb_sectors)
{
    return bdrv_write(blk->bs, sector_num, buf, nb_sectors);
}

BlockAIOCB *blk_aio_write_zeroes(BlockBackend *blk, int64_t sector_num,
                                 int nb_sectors, BdrvRequestFlags flags,
                                 BlockCompletionFunc *cb, void *opaque)
{
    return bdrv_aio_write_zeroes(blk->bs, sector_num, nb_sectors, flags,
                                 cb, opaque);
}

int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int count)
{
    return bdrv_pread(blk->bs, offset, buf, count);
}

int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int count)
{
    return bdrv_pwrite(blk->bs, offset, buf, count);
}

int64_t blk_getlength(BlockBackend *blk)
{
    return bdrv_getlength(blk->bs);
}

void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr)
{
    bdrv_get_geometry(blk->bs, nb_sectors_ptr);
}

BlockAIOCB *blk_aio_readv(BlockBackend *blk, int64_t sector_num,
                          QEMUIOVector *iov, int nb_sectors,
                          BlockCompletionFunc *cb, void *opaque)
{
    return bdrv_aio_readv(blk->bs, sector_num, iov, nb_sectors, cb, opaque);
}

BlockAIOCB *blk_aio_writev(BlockBackend *blk, int64_t sector_num,
                           QEMUIOVector *iov, int nb_sectors,
                           BlockCompletionFunc *cb, void *opaque)
{
    return bdrv_aio_writev(blk->bs, sector_num, iov, nb_sectors, cb, opaque);
}

BlockAIOCB *blk_aio_flush(BlockBackend *blk,
                          BlockCompletionFunc *cb, void *opaque)
{
    return bdrv_aio_flush(blk->bs, cb, opaque);
}

BlockAIOCB *blk_aio_discard(BlockBackend *blk,
                            int64_t sector_num, int nb_sectors,
                            BlockCompletionFunc *cb, void *opaque)
{
    return bdrv_aio_discard(blk->bs, sector_num, nb_sectors, cb, opaque);
}

void blk_aio_cancel(BlockAIOCB *acb)
{
    bdrv_aio_cancel(acb);
}

void blk_aio_cancel_async(BlockAIOCB *acb)
{
    bdrv_aio_cancel_async(acb);
}

int blk_aio_multiwrite(BlockBackend *blk, BlockRequest *reqs, int num_reqs)
{
    return bdrv_aio_multiwrite(blk->bs, reqs, num_reqs);
}

int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf)
{
    return bdrv_ioctl(blk->bs, req, buf);
}

BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf,
                          BlockCompletionFunc *cb, void *opaque)
{
    return bdrv_aio_ioctl(blk->bs, req, buf, cb, opaque);
}

int blk_co_discard(BlockBackend *blk, int64_t sector_num, int nb_sectors)
{
    return bdrv_co_discard(blk->bs, sector_num, nb_sectors);
}

int blk_co_flush(BlockBackend *blk)
{
    return bdrv_co_flush(blk->bs);
}

int blk_flush(BlockBackend *blk)
{
    return bdrv_flush(blk->bs);
}

int blk_flush_all(void)
{
    return bdrv_flush_all();
}

void blk_drain_all(void)
{
    bdrv_drain_all();
}

BlockdevOnError blk_get_on_error(BlockBackend *blk, bool is_read)
{
    return bdrv_get_on_error(blk->bs, is_read);
}

BlockErrorAction blk_get_error_action(BlockBackend *blk, bool is_read,
                                      int error)
{
    return bdrv_get_error_action(blk->bs, is_read, error);
}

void blk_error_action(BlockBackend *blk, BlockErrorAction action,
                      bool is_read, int error)
{
    bdrv_error_action(blk->bs, action, is_read, error);
}

int blk_is_read_only(BlockBackend *blk)
{
    return bdrv_is_read_only(blk->bs);
}

int blk_is_sg(BlockBackend *blk)
{
    return bdrv_is_sg(blk->bs);
}

int blk_enable_write_cache(BlockBackend *blk)
{
    return bdrv_enable_write_cache(blk->bs);
}

void blk_set_enable_write_cache(BlockBackend *blk, bool wce)
{
    bdrv_set_enable_write_cache(blk->bs, wce);
}

void blk_invalidate_cache(BlockBackend *blk, Error **errp)
{
    bdrv_invalidate_cache(blk->bs, errp);
}

int blk_is_inserted(BlockBackend *blk)
{
    return bdrv_is_inserted(blk->bs);
}

void blk_lock_medium(BlockBackend *blk, bool locked)
{
    bdrv_lock_medium(blk->bs, locked);
}

void blk_eject(BlockBackend *blk, bool eject_flag)
{
    bdrv_eject(blk->bs, eject_flag);
}

int blk_get_flags(BlockBackend *blk)
{
    return bdrv_get_flags(blk->bs);
}

void blk_set_guest_block_size(BlockBackend *blk, int align)
{
    bdrv_set_guest_block_size(blk->bs, align);
}

void *blk_blockalign(BlockBackend *blk, size_t size)
{
    return qemu_blockalign(blk ? blk->bs : NULL, size);
}

bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp)
{
    return bdrv_op_is_blocked(blk->bs, op, errp);
}

void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason)
{
    bdrv_op_unblock(blk->bs, op, reason);
}

void blk_op_block_all(BlockBackend *blk, Error *reason)
{
    bdrv_op_block_all(blk->bs, reason);
}

void blk_op_unblock_all(BlockBackend *blk, Error *reason)
{
    bdrv_op_unblock_all(blk->bs, reason);
}

AioContext *blk_get_aio_context(BlockBackend *blk)
{
    return bdrv_get_aio_context(blk->bs);
}

void blk_set_aio_context(BlockBackend *blk, AioContext *new_context)
{
    bdrv_set_aio_context(blk->bs, new_context);
}

void blk_add_aio_context_notifier(BlockBackend *blk,
        void (*attached_aio_context)(AioContext *new_context, void *opaque),
        void (*detach_aio_context)(void *opaque), void *opaque)
{
    bdrv_add_aio_context_notifier(blk->bs, attached_aio_context,
                                  detach_aio_context, opaque);
}

void blk_remove_aio_context_notifier(BlockBackend *blk,
                                     void (*attached_aio_context)(AioContext *,
                                                                  void *),
                                     void (*detach_aio_context)(void *),
                                     void *opaque)
{
    bdrv_remove_aio_context_notifier(blk->bs, attached_aio_context,
                                     detach_aio_context, opaque);
}

void blk_add_close_notifier(BlockBackend *blk, Notifier *notify)
{
    bdrv_add_close_notifier(blk->bs, notify);
}

void blk_io_plug(BlockBackend *blk)
{
    bdrv_io_plug(blk->bs);
}

void blk_io_unplug(BlockBackend *blk)
{
    bdrv_io_unplug(blk->bs);
}

BlockAcctStats *blk_get_stats(BlockBackend *blk)
{
    return bdrv_get_stats(blk->bs);
}

void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk,
                  BlockCompletionFunc *cb, void *opaque)
{
    return qemu_aio_get(aiocb_info, blk_bs(blk), cb, opaque);
}