4 * Copyright (C) 2014-2016 Red Hat, Inc.
7 * Markus Armbruster <armbru@redhat.com>,
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.
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 "sysemu/blockdev.h"
19 #include "sysemu/sysemu.h"
20 #include "qapi-event.h"
24 /* Number of coroutines to reserve per attached device model */
25 #define COROUTINE_POOL_RESERVATION 64
27 #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
29 static AioContext
*blk_aiocb_get_aio_context(BlockAIOCB
*acb
);
35 DriveInfo
*legacy_dinfo
; /* null unless created by drive_new() */
36 QTAILQ_ENTRY(BlockBackend
) link
; /* for block_backends */
37 QTAILQ_ENTRY(BlockBackend
) monitor_link
; /* for monitor_block_backends */
38 BlockBackendPublic
public;
40 void *dev
; /* attached device model, if any */
41 bool legacy_dev
; /* true if dev is not a DeviceState */
42 /* TODO change to DeviceState when all users are qdevified */
43 const BlockDevOps
*dev_ops
;
46 /* the block size for which the guest device expects atomicity */
49 /* If the BDS tree is removed, some of its options are stored here (which
50 * can be used to restore those options in the new BDS on insert) */
51 BlockBackendRootState root_state
;
53 bool enable_write_cache
;
55 /* I/O stats (display with "info blockstats"). */
58 BlockdevOnError on_read_error
, on_write_error
;
59 bool iostatus_enabled
;
60 BlockDeviceIoStatus iostatus
;
65 bool allow_write_beyond_eof
;
67 NotifierList remove_bs_notifiers
, insert_bs_notifiers
;
70 typedef struct BlockBackendAIOCB
{
76 static const AIOCBInfo block_backend_aiocb_info
= {
77 .get_aio_context
= blk_aiocb_get_aio_context
,
78 .aiocb_size
= sizeof(BlockBackendAIOCB
),
81 static void drive_info_del(DriveInfo
*dinfo
);
82 static BlockBackend
*bdrv_first_blk(BlockDriverState
*bs
);
84 /* All BlockBackends */
85 static QTAILQ_HEAD(, BlockBackend
) block_backends
=
86 QTAILQ_HEAD_INITIALIZER(block_backends
);
88 /* All BlockBackends referenced by the monitor and which are iterated through by
90 static QTAILQ_HEAD(, BlockBackend
) monitor_block_backends
=
91 QTAILQ_HEAD_INITIALIZER(monitor_block_backends
);
93 static void blk_root_inherit_options(int *child_flags
, QDict
*child_options
,
94 int parent_flags
, QDict
*parent_options
)
96 /* We're not supposed to call this function for root nodes */
99 static void blk_root_drained_begin(BdrvChild
*child
);
100 static void blk_root_drained_end(BdrvChild
*child
);
102 static void blk_root_change_media(BdrvChild
*child
, bool load
);
103 static void blk_root_resize(BdrvChild
*child
);
105 static const char *blk_root_get_name(BdrvChild
*child
)
107 return blk_name(child
->opaque
);
110 static const BdrvChildRole child_root
= {
111 .inherit_options
= blk_root_inherit_options
,
113 .change_media
= blk_root_change_media
,
114 .resize
= blk_root_resize
,
115 .get_name
= blk_root_get_name
,
117 .drained_begin
= blk_root_drained_begin
,
118 .drained_end
= blk_root_drained_end
,
122 * Create a new BlockBackend with a reference count of one.
123 * Store an error through @errp on failure, unless it's null.
124 * Return the new BlockBackend on success, null on failure.
126 BlockBackend
*blk_new(void)
130 blk
= g_new0(BlockBackend
, 1);
133 blk
->shared_perm
= BLK_PERM_ALL
;
134 blk_set_enable_write_cache(blk
, true);
136 qemu_co_queue_init(&blk
->public.throttled_reqs
[0]);
137 qemu_co_queue_init(&blk
->public.throttled_reqs
[1]);
139 notifier_list_init(&blk
->remove_bs_notifiers
);
140 notifier_list_init(&blk
->insert_bs_notifiers
);
142 QTAILQ_INSERT_TAIL(&block_backends
, blk
, link
);
147 * Creates a new BlockBackend, opens a new BlockDriverState, and connects both.
149 * Just as with bdrv_open(), after having called this function the reference to
150 * @options belongs to the block layer (even on failure).
152 * TODO: Remove @filename and @flags; it should be possible to specify a whole
153 * BDS tree just by specifying the @options QDict (or @reference,
154 * alternatively). At the time of adding this function, this is not possible,
155 * though, so callers of this function have to be able to specify @filename and
158 BlockBackend
*blk_new_open(const char *filename
, const char *reference
,
159 QDict
*options
, int flags
, Error
**errp
)
162 BlockDriverState
*bs
;
165 bs
= bdrv_open(filename
, reference
, options
, flags
, errp
);
171 /* FIXME Use real permissions */
172 blk
->root
= bdrv_root_attach_child(bs
, "root", &child_root
,
173 0, BLK_PERM_ALL
, blk
, &error_abort
);
178 static void blk_delete(BlockBackend
*blk
)
180 assert(!blk
->refcnt
);
186 assert(QLIST_EMPTY(&blk
->remove_bs_notifiers
.notifiers
));
187 assert(QLIST_EMPTY(&blk
->insert_bs_notifiers
.notifiers
));
188 QTAILQ_REMOVE(&block_backends
, blk
, link
);
189 drive_info_del(blk
->legacy_dinfo
);
190 block_acct_cleanup(&blk
->stats
);
194 static void drive_info_del(DriveInfo
*dinfo
)
199 qemu_opts_del(dinfo
->opts
);
200 g_free(dinfo
->serial
);
204 int blk_get_refcnt(BlockBackend
*blk
)
206 return blk
? blk
->refcnt
: 0;
210 * Increment @blk's reference count.
211 * @blk must not be null.
213 void blk_ref(BlockBackend
*blk
)
219 * Decrement @blk's reference count.
220 * If this drops it to zero, destroy @blk.
221 * For convenience, do nothing if @blk is null.
223 void blk_unref(BlockBackend
*blk
)
226 assert(blk
->refcnt
> 0);
227 if (!--blk
->refcnt
) {
234 * Behaves similarly to blk_next() but iterates over all BlockBackends, even the
235 * ones which are hidden (i.e. are not referenced by the monitor).
237 static BlockBackend
*blk_all_next(BlockBackend
*blk
)
239 return blk
? QTAILQ_NEXT(blk
, link
)
240 : QTAILQ_FIRST(&block_backends
);
243 void blk_remove_all_bs(void)
245 BlockBackend
*blk
= NULL
;
247 while ((blk
= blk_all_next(blk
)) != NULL
) {
248 AioContext
*ctx
= blk_get_aio_context(blk
);
250 aio_context_acquire(ctx
);
254 aio_context_release(ctx
);
259 * Return the monitor-owned BlockBackend after @blk.
260 * If @blk is null, return the first one.
261 * Else, return @blk's next sibling, which may be null.
263 * To iterate over all BlockBackends, do
264 * for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
268 BlockBackend
*blk_next(BlockBackend
*blk
)
270 return blk
? QTAILQ_NEXT(blk
, monitor_link
)
271 : QTAILQ_FIRST(&monitor_block_backends
);
274 /* Iterates over all top-level BlockDriverStates, i.e. BDSs that are owned by
275 * the monitor or attached to a BlockBackend */
276 BlockDriverState
*bdrv_next(BdrvNextIterator
*it
)
278 BlockDriverState
*bs
;
280 /* First, return all root nodes of BlockBackends. In order to avoid
281 * returning a BDS twice when multiple BBs refer to it, we only return it
282 * if the BB is the first one in the parent list of the BDS. */
283 if (it
->phase
== BDRV_NEXT_BACKEND_ROOTS
) {
285 it
->blk
= blk_all_next(it
->blk
);
286 bs
= it
->blk
? blk_bs(it
->blk
) : NULL
;
287 } while (it
->blk
&& (bs
== NULL
|| bdrv_first_blk(bs
) != it
->blk
));
292 it
->phase
= BDRV_NEXT_MONITOR_OWNED
;
295 /* Then return the monitor-owned BDSes without a BB attached. Ignore all
296 * BDSes that are attached to a BlockBackend here; they have been handled
297 * by the above block already */
299 it
->bs
= bdrv_next_monitor_owned(it
->bs
);
301 } while (bs
&& bdrv_has_blk(bs
));
306 BlockDriverState
*bdrv_first(BdrvNextIterator
*it
)
308 *it
= (BdrvNextIterator
) {
309 .phase
= BDRV_NEXT_BACKEND_ROOTS
,
312 return bdrv_next(it
);
316 * Add a BlockBackend into the list of backends referenced by the monitor, with
317 * the given @name acting as the handle for the monitor.
318 * Strictly for use by blockdev.c.
320 * @name must not be null or empty.
322 * Returns true on success and false on failure. In the latter case, an Error
323 * object is returned through @errp.
325 bool monitor_add_blk(BlockBackend
*blk
, const char *name
, Error
**errp
)
328 assert(name
&& name
[0]);
330 if (!id_wellformed(name
)) {
331 error_setg(errp
, "Invalid device name");
334 if (blk_by_name(name
)) {
335 error_setg(errp
, "Device with id '%s' already exists", name
);
338 if (bdrv_find_node(name
)) {
340 "Device name '%s' conflicts with an existing node name",
345 blk
->name
= g_strdup(name
);
346 QTAILQ_INSERT_TAIL(&monitor_block_backends
, blk
, monitor_link
);
351 * Remove a BlockBackend from the list of backends referenced by the monitor.
352 * Strictly for use by blockdev.c.
354 void monitor_remove_blk(BlockBackend
*blk
)
360 QTAILQ_REMOVE(&monitor_block_backends
, blk
, monitor_link
);
366 * Return @blk's name, a non-null string.
367 * Returns an empty string iff @blk is not referenced by the monitor.
369 const char *blk_name(BlockBackend
*blk
)
371 return blk
->name
?: "";
375 * Return the BlockBackend with name @name if it exists, else null.
376 * @name must not be null.
378 BlockBackend
*blk_by_name(const char *name
)
380 BlockBackend
*blk
= NULL
;
383 while ((blk
= blk_next(blk
)) != NULL
) {
384 if (!strcmp(name
, blk
->name
)) {
392 * Return the BlockDriverState attached to @blk if any, else null.
394 BlockDriverState
*blk_bs(BlockBackend
*blk
)
396 return blk
->root
? blk
->root
->bs
: NULL
;
399 static BlockBackend
*bdrv_first_blk(BlockDriverState
*bs
)
402 QLIST_FOREACH(child
, &bs
->parents
, next_parent
) {
403 if (child
->role
== &child_root
) {
404 return child
->opaque
;
412 * Returns true if @bs has an associated BlockBackend.
414 bool bdrv_has_blk(BlockDriverState
*bs
)
416 return bdrv_first_blk(bs
) != NULL
;
420 * Returns true if @bs has only BlockBackends as parents.
422 bool bdrv_is_root_node(BlockDriverState
*bs
)
426 QLIST_FOREACH(c
, &bs
->parents
, next_parent
) {
427 if (c
->role
!= &child_root
) {
436 * Return @blk's DriveInfo if any, else null.
438 DriveInfo
*blk_legacy_dinfo(BlockBackend
*blk
)
440 return blk
->legacy_dinfo
;
444 * Set @blk's DriveInfo to @dinfo, and return it.
445 * @blk must not have a DriveInfo set already.
446 * No other BlockBackend may have the same DriveInfo set.
448 DriveInfo
*blk_set_legacy_dinfo(BlockBackend
*blk
, DriveInfo
*dinfo
)
450 assert(!blk
->legacy_dinfo
);
451 return blk
->legacy_dinfo
= dinfo
;
455 * Return the BlockBackend with DriveInfo @dinfo.
458 BlockBackend
*blk_by_legacy_dinfo(DriveInfo
*dinfo
)
460 BlockBackend
*blk
= NULL
;
462 while ((blk
= blk_next(blk
)) != NULL
) {
463 if (blk
->legacy_dinfo
== dinfo
) {
471 * Returns a pointer to the publicly accessible fields of @blk.
473 BlockBackendPublic
*blk_get_public(BlockBackend
*blk
)
479 * Returns a BlockBackend given the associated @public fields.
481 BlockBackend
*blk_by_public(BlockBackendPublic
*public)
483 return container_of(public, BlockBackend
, public);
487 * Disassociates the currently associated BlockDriverState from @blk.
489 void blk_remove_bs(BlockBackend
*blk
)
491 notifier_list_notify(&blk
->remove_bs_notifiers
, blk
);
492 if (blk
->public.throttle_state
) {
493 throttle_timers_detach_aio_context(&blk
->public.throttle_timers
);
496 blk_update_root_state(blk
);
498 bdrv_root_unref_child(blk
->root
);
503 * Associates a new BlockDriverState with @blk.
505 void blk_insert_bs(BlockBackend
*blk
, BlockDriverState
*bs
)
508 /* FIXME Use real permissions */
509 blk
->root
= bdrv_root_attach_child(bs
, "root", &child_root
,
510 0, BLK_PERM_ALL
, blk
, &error_abort
);
512 notifier_list_notify(&blk
->insert_bs_notifiers
, blk
);
513 if (blk
->public.throttle_state
) {
514 throttle_timers_attach_aio_context(
515 &blk
->public.throttle_timers
, bdrv_get_aio_context(bs
));
520 * Sets the permission bitmasks that the user of the BlockBackend needs.
522 int blk_set_perm(BlockBackend
*blk
, uint64_t perm
, uint64_t shared_perm
,
528 ret
= bdrv_child_try_set_perm(blk
->root
, perm
, shared_perm
, errp
);
535 blk
->shared_perm
= shared_perm
;
540 static int blk_do_attach_dev(BlockBackend
*blk
, void *dev
)
547 blk
->legacy_dev
= false;
548 blk_iostatus_reset(blk
);
553 * Attach device model @dev to @blk.
554 * Return 0 on success, -EBUSY when a device model is attached already.
556 int blk_attach_dev(BlockBackend
*blk
, DeviceState
*dev
)
558 return blk_do_attach_dev(blk
, dev
);
562 * Attach device model @dev to @blk.
563 * @blk must not have a device model attached already.
564 * TODO qdevified devices don't use this, remove when devices are qdevified
566 void blk_attach_dev_legacy(BlockBackend
*blk
, void *dev
)
568 if (blk_do_attach_dev(blk
, dev
) < 0) {
571 blk
->legacy_dev
= true;
575 * Detach device model @dev from @blk.
576 * @dev must be currently attached to @blk.
578 void blk_detach_dev(BlockBackend
*blk
, void *dev
)
579 /* TODO change to DeviceState *dev when all users are qdevified */
581 assert(blk
->dev
== dev
);
584 blk
->dev_opaque
= NULL
;
585 blk
->guest_block_size
= 512;
586 blk_set_perm(blk
, 0, BLK_PERM_ALL
, &error_abort
);
591 * Return the device model attached to @blk if any, else null.
593 void *blk_get_attached_dev(BlockBackend
*blk
)
594 /* TODO change to return DeviceState * when all users are qdevified */
599 /* Return the qdev ID, or if no ID is assigned the QOM path, of the block
600 * device attached to the BlockBackend. */
601 static char *blk_get_attached_dev_id(BlockBackend
*blk
)
605 assert(!blk
->legacy_dev
);
610 } else if (dev
->id
) {
611 return g_strdup(dev
->id
);
613 return object_get_canonical_path(OBJECT(dev
));
617 * Return the BlockBackend which has the device model @dev attached if it
620 * @dev must not be null.
622 BlockBackend
*blk_by_dev(void *dev
)
624 BlockBackend
*blk
= NULL
;
627 while ((blk
= blk_all_next(blk
)) != NULL
) {
628 if (blk
->dev
== dev
) {
636 * Set @blk's device model callbacks to @ops.
637 * @opaque is the opaque argument to pass to the callbacks.
638 * This is for use by device models.
640 void blk_set_dev_ops(BlockBackend
*blk
, const BlockDevOps
*ops
,
643 /* All drivers that use blk_set_dev_ops() are qdevified and we want to keep
644 * it that way, so we can assume blk->dev is a DeviceState if blk->dev_ops
646 assert(!blk
->legacy_dev
);
649 blk
->dev_opaque
= opaque
;
653 * Notify @blk's attached device model of media change.
654 * If @load is true, notify of media load.
655 * Else, notify of media eject.
656 * Also send DEVICE_TRAY_MOVED events as appropriate.
658 void blk_dev_change_media_cb(BlockBackend
*blk
, bool load
)
660 if (blk
->dev_ops
&& blk
->dev_ops
->change_media_cb
) {
661 bool tray_was_open
, tray_is_open
;
663 assert(!blk
->legacy_dev
);
665 tray_was_open
= blk_dev_is_tray_open(blk
);
666 blk
->dev_ops
->change_media_cb(blk
->dev_opaque
, load
);
667 tray_is_open
= blk_dev_is_tray_open(blk
);
669 if (tray_was_open
!= tray_is_open
) {
670 char *id
= blk_get_attached_dev_id(blk
);
671 qapi_event_send_device_tray_moved(blk_name(blk
), id
, tray_is_open
,
678 static void blk_root_change_media(BdrvChild
*child
, bool load
)
680 blk_dev_change_media_cb(child
->opaque
, load
);
684 * Does @blk's attached device model have removable media?
685 * %true if no device model is attached.
687 bool blk_dev_has_removable_media(BlockBackend
*blk
)
689 return !blk
->dev
|| (blk
->dev_ops
&& blk
->dev_ops
->change_media_cb
);
693 * Does @blk's attached device model have a tray?
695 bool blk_dev_has_tray(BlockBackend
*blk
)
697 return blk
->dev_ops
&& blk
->dev_ops
->is_tray_open
;
701 * Notify @blk's attached device model of a media eject request.
702 * If @force is true, the medium is about to be yanked out forcefully.
704 void blk_dev_eject_request(BlockBackend
*blk
, bool force
)
706 if (blk
->dev_ops
&& blk
->dev_ops
->eject_request_cb
) {
707 blk
->dev_ops
->eject_request_cb(blk
->dev_opaque
, force
);
712 * Does @blk's attached device model have a tray, and is it open?
714 bool blk_dev_is_tray_open(BlockBackend
*blk
)
716 if (blk_dev_has_tray(blk
)) {
717 return blk
->dev_ops
->is_tray_open(blk
->dev_opaque
);
723 * Does @blk's attached device model have the medium locked?
724 * %false if the device model has no such lock.
726 bool blk_dev_is_medium_locked(BlockBackend
*blk
)
728 if (blk
->dev_ops
&& blk
->dev_ops
->is_medium_locked
) {
729 return blk
->dev_ops
->is_medium_locked(blk
->dev_opaque
);
735 * Notify @blk's attached device model of a backend size change.
737 static void blk_root_resize(BdrvChild
*child
)
739 BlockBackend
*blk
= child
->opaque
;
741 if (blk
->dev_ops
&& blk
->dev_ops
->resize_cb
) {
742 blk
->dev_ops
->resize_cb(blk
->dev_opaque
);
746 void blk_iostatus_enable(BlockBackend
*blk
)
748 blk
->iostatus_enabled
= true;
749 blk
->iostatus
= BLOCK_DEVICE_IO_STATUS_OK
;
752 /* The I/O status is only enabled if the drive explicitly
753 * enables it _and_ the VM is configured to stop on errors */
754 bool blk_iostatus_is_enabled(const BlockBackend
*blk
)
756 return (blk
->iostatus_enabled
&&
757 (blk
->on_write_error
== BLOCKDEV_ON_ERROR_ENOSPC
||
758 blk
->on_write_error
== BLOCKDEV_ON_ERROR_STOP
||
759 blk
->on_read_error
== BLOCKDEV_ON_ERROR_STOP
));
762 BlockDeviceIoStatus
blk_iostatus(const BlockBackend
*blk
)
764 return blk
->iostatus
;
767 void blk_iostatus_disable(BlockBackend
*blk
)
769 blk
->iostatus_enabled
= false;
772 void blk_iostatus_reset(BlockBackend
*blk
)
774 if (blk_iostatus_is_enabled(blk
)) {
775 BlockDriverState
*bs
= blk_bs(blk
);
776 blk
->iostatus
= BLOCK_DEVICE_IO_STATUS_OK
;
778 block_job_iostatus_reset(bs
->job
);
783 void blk_iostatus_set_err(BlockBackend
*blk
, int error
)
785 assert(blk_iostatus_is_enabled(blk
));
786 if (blk
->iostatus
== BLOCK_DEVICE_IO_STATUS_OK
) {
787 blk
->iostatus
= error
== ENOSPC
? BLOCK_DEVICE_IO_STATUS_NOSPACE
:
788 BLOCK_DEVICE_IO_STATUS_FAILED
;
792 void blk_set_allow_write_beyond_eof(BlockBackend
*blk
, bool allow
)
794 blk
->allow_write_beyond_eof
= allow
;
797 static int blk_check_byte_request(BlockBackend
*blk
, int64_t offset
,
802 if (size
> INT_MAX
) {
806 if (!blk_is_available(blk
)) {
814 if (!blk
->allow_write_beyond_eof
) {
815 len
= blk_getlength(blk
);
820 if (offset
> len
|| len
- offset
< size
) {
828 int coroutine_fn
blk_co_preadv(BlockBackend
*blk
, int64_t offset
,
829 unsigned int bytes
, QEMUIOVector
*qiov
,
830 BdrvRequestFlags flags
)
833 BlockDriverState
*bs
= blk_bs(blk
);
835 trace_blk_co_preadv(blk
, bs
, offset
, bytes
, flags
);
837 ret
= blk_check_byte_request(blk
, offset
, bytes
);
842 bdrv_inc_in_flight(bs
);
844 /* throttling disk I/O */
845 if (blk
->public.throttle_state
) {
846 throttle_group_co_io_limits_intercept(blk
, bytes
, false);
849 ret
= bdrv_co_preadv(blk
->root
, offset
, bytes
, qiov
, flags
);
850 bdrv_dec_in_flight(bs
);
854 int coroutine_fn
blk_co_pwritev(BlockBackend
*blk
, int64_t offset
,
855 unsigned int bytes
, QEMUIOVector
*qiov
,
856 BdrvRequestFlags flags
)
859 BlockDriverState
*bs
= blk_bs(blk
);
861 trace_blk_co_pwritev(blk
, bs
, offset
, bytes
, flags
);
863 ret
= blk_check_byte_request(blk
, offset
, bytes
);
868 bdrv_inc_in_flight(bs
);
870 /* throttling disk I/O */
871 if (blk
->public.throttle_state
) {
872 throttle_group_co_io_limits_intercept(blk
, bytes
, true);
875 if (!blk
->enable_write_cache
) {
876 flags
|= BDRV_REQ_FUA
;
879 ret
= bdrv_co_pwritev(blk
->root
, offset
, bytes
, qiov
, flags
);
880 bdrv_dec_in_flight(bs
);
884 typedef struct BlkRwCo
{
889 BdrvRequestFlags flags
;
892 static void blk_read_entry(void *opaque
)
894 BlkRwCo
*rwco
= opaque
;
896 rwco
->ret
= blk_co_preadv(rwco
->blk
, rwco
->offset
, rwco
->qiov
->size
,
897 rwco
->qiov
, rwco
->flags
);
900 static void blk_write_entry(void *opaque
)
902 BlkRwCo
*rwco
= opaque
;
904 rwco
->ret
= blk_co_pwritev(rwco
->blk
, rwco
->offset
, rwco
->qiov
->size
,
905 rwco
->qiov
, rwco
->flags
);
908 static int blk_prw(BlockBackend
*blk
, int64_t offset
, uint8_t *buf
,
909 int64_t bytes
, CoroutineEntry co_entry
,
910 BdrvRequestFlags flags
)
916 iov
= (struct iovec
) {
920 qemu_iovec_init_external(&qiov
, &iov
, 1);
930 if (qemu_in_coroutine()) {
931 /* Fast-path if already in coroutine context */
934 Coroutine
*co
= qemu_coroutine_create(co_entry
, &rwco
);
935 qemu_coroutine_enter(co
);
936 BDRV_POLL_WHILE(blk_bs(blk
), rwco
.ret
== NOT_DONE
);
942 int blk_pread_unthrottled(BlockBackend
*blk
, int64_t offset
, uint8_t *buf
,
947 ret
= blk_check_byte_request(blk
, offset
, count
);
952 blk_root_drained_begin(blk
->root
);
953 ret
= blk_pread(blk
, offset
, buf
, count
);
954 blk_root_drained_end(blk
->root
);
958 int blk_pwrite_zeroes(BlockBackend
*blk
, int64_t offset
,
959 int count
, BdrvRequestFlags flags
)
961 return blk_prw(blk
, offset
, NULL
, count
, blk_write_entry
,
962 flags
| BDRV_REQ_ZERO_WRITE
);
965 int blk_make_zero(BlockBackend
*blk
, BdrvRequestFlags flags
)
967 return bdrv_make_zero(blk
->root
, flags
);
970 static void error_callback_bh(void *opaque
)
972 struct BlockBackendAIOCB
*acb
= opaque
;
974 bdrv_dec_in_flight(acb
->common
.bs
);
975 acb
->common
.cb(acb
->common
.opaque
, acb
->ret
);
979 BlockAIOCB
*blk_abort_aio_request(BlockBackend
*blk
,
980 BlockCompletionFunc
*cb
,
981 void *opaque
, int ret
)
983 struct BlockBackendAIOCB
*acb
;
985 bdrv_inc_in_flight(blk_bs(blk
));
986 acb
= blk_aio_get(&block_backend_aiocb_info
, blk
, cb
, opaque
);
990 aio_bh_schedule_oneshot(blk_get_aio_context(blk
), error_callback_bh
, acb
);
994 typedef struct BlkAioEmAIOCB
{
1001 static const AIOCBInfo blk_aio_em_aiocb_info
= {
1002 .aiocb_size
= sizeof(BlkAioEmAIOCB
),
1005 static void blk_aio_complete(BlkAioEmAIOCB
*acb
)
1007 if (acb
->has_returned
) {
1008 bdrv_dec_in_flight(acb
->common
.bs
);
1009 acb
->common
.cb(acb
->common
.opaque
, acb
->rwco
.ret
);
1010 qemu_aio_unref(acb
);
1014 static void blk_aio_complete_bh(void *opaque
)
1016 BlkAioEmAIOCB
*acb
= opaque
;
1017 assert(acb
->has_returned
);
1018 blk_aio_complete(acb
);
1021 static BlockAIOCB
*blk_aio_prwv(BlockBackend
*blk
, int64_t offset
, int bytes
,
1022 QEMUIOVector
*qiov
, CoroutineEntry co_entry
,
1023 BdrvRequestFlags flags
,
1024 BlockCompletionFunc
*cb
, void *opaque
)
1029 bdrv_inc_in_flight(blk_bs(blk
));
1030 acb
= blk_aio_get(&blk_aio_em_aiocb_info
, blk
, cb
, opaque
);
1031 acb
->rwco
= (BlkRwCo
) {
1039 acb
->has_returned
= false;
1041 co
= qemu_coroutine_create(co_entry
, acb
);
1042 qemu_coroutine_enter(co
);
1044 acb
->has_returned
= true;
1045 if (acb
->rwco
.ret
!= NOT_DONE
) {
1046 aio_bh_schedule_oneshot(blk_get_aio_context(blk
),
1047 blk_aio_complete_bh
, acb
);
1050 return &acb
->common
;
1053 static void blk_aio_read_entry(void *opaque
)
1055 BlkAioEmAIOCB
*acb
= opaque
;
1056 BlkRwCo
*rwco
= &acb
->rwco
;
1058 assert(rwco
->qiov
->size
== acb
->bytes
);
1059 rwco
->ret
= blk_co_preadv(rwco
->blk
, rwco
->offset
, acb
->bytes
,
1060 rwco
->qiov
, rwco
->flags
);
1061 blk_aio_complete(acb
);
1064 static void blk_aio_write_entry(void *opaque
)
1066 BlkAioEmAIOCB
*acb
= opaque
;
1067 BlkRwCo
*rwco
= &acb
->rwco
;
1069 assert(!rwco
->qiov
|| rwco
->qiov
->size
== acb
->bytes
);
1070 rwco
->ret
= blk_co_pwritev(rwco
->blk
, rwco
->offset
, acb
->bytes
,
1071 rwco
->qiov
, rwco
->flags
);
1072 blk_aio_complete(acb
);
1075 BlockAIOCB
*blk_aio_pwrite_zeroes(BlockBackend
*blk
, int64_t offset
,
1076 int count
, BdrvRequestFlags flags
,
1077 BlockCompletionFunc
*cb
, void *opaque
)
1079 return blk_aio_prwv(blk
, offset
, count
, NULL
, blk_aio_write_entry
,
1080 flags
| BDRV_REQ_ZERO_WRITE
, cb
, opaque
);
1083 int blk_pread(BlockBackend
*blk
, int64_t offset
, void *buf
, int count
)
1085 int ret
= blk_prw(blk
, offset
, buf
, count
, blk_read_entry
, 0);
1092 int blk_pwrite(BlockBackend
*blk
, int64_t offset
, const void *buf
, int count
,
1093 BdrvRequestFlags flags
)
1095 int ret
= blk_prw(blk
, offset
, (void *) buf
, count
, blk_write_entry
,
1103 int64_t blk_getlength(BlockBackend
*blk
)
1105 if (!blk_is_available(blk
)) {
1109 return bdrv_getlength(blk_bs(blk
));
1112 void blk_get_geometry(BlockBackend
*blk
, uint64_t *nb_sectors_ptr
)
1115 *nb_sectors_ptr
= 0;
1117 bdrv_get_geometry(blk_bs(blk
), nb_sectors_ptr
);
1121 int64_t blk_nb_sectors(BlockBackend
*blk
)
1123 if (!blk_is_available(blk
)) {
1127 return bdrv_nb_sectors(blk_bs(blk
));
1130 BlockAIOCB
*blk_aio_preadv(BlockBackend
*blk
, int64_t offset
,
1131 QEMUIOVector
*qiov
, BdrvRequestFlags flags
,
1132 BlockCompletionFunc
*cb
, void *opaque
)
1134 return blk_aio_prwv(blk
, offset
, qiov
->size
, qiov
,
1135 blk_aio_read_entry
, flags
, cb
, opaque
);
1138 BlockAIOCB
*blk_aio_pwritev(BlockBackend
*blk
, int64_t offset
,
1139 QEMUIOVector
*qiov
, BdrvRequestFlags flags
,
1140 BlockCompletionFunc
*cb
, void *opaque
)
1142 return blk_aio_prwv(blk
, offset
, qiov
->size
, qiov
,
1143 blk_aio_write_entry
, flags
, cb
, opaque
);
1146 static void blk_aio_flush_entry(void *opaque
)
1148 BlkAioEmAIOCB
*acb
= opaque
;
1149 BlkRwCo
*rwco
= &acb
->rwco
;
1151 rwco
->ret
= blk_co_flush(rwco
->blk
);
1152 blk_aio_complete(acb
);
1155 BlockAIOCB
*blk_aio_flush(BlockBackend
*blk
,
1156 BlockCompletionFunc
*cb
, void *opaque
)
1158 return blk_aio_prwv(blk
, 0, 0, NULL
, blk_aio_flush_entry
, 0, cb
, opaque
);
1161 static void blk_aio_pdiscard_entry(void *opaque
)
1163 BlkAioEmAIOCB
*acb
= opaque
;
1164 BlkRwCo
*rwco
= &acb
->rwco
;
1166 rwco
->ret
= blk_co_pdiscard(rwco
->blk
, rwco
->offset
, acb
->bytes
);
1167 blk_aio_complete(acb
);
1170 BlockAIOCB
*blk_aio_pdiscard(BlockBackend
*blk
,
1171 int64_t offset
, int count
,
1172 BlockCompletionFunc
*cb
, void *opaque
)
1174 return blk_aio_prwv(blk
, offset
, count
, NULL
, blk_aio_pdiscard_entry
, 0,
1178 void blk_aio_cancel(BlockAIOCB
*acb
)
1180 bdrv_aio_cancel(acb
);
1183 void blk_aio_cancel_async(BlockAIOCB
*acb
)
1185 bdrv_aio_cancel_async(acb
);
1188 int blk_co_ioctl(BlockBackend
*blk
, unsigned long int req
, void *buf
)
1190 if (!blk_is_available(blk
)) {
1194 return bdrv_co_ioctl(blk_bs(blk
), req
, buf
);
1197 static void blk_ioctl_entry(void *opaque
)
1199 BlkRwCo
*rwco
= opaque
;
1200 rwco
->ret
= blk_co_ioctl(rwco
->blk
, rwco
->offset
,
1201 rwco
->qiov
->iov
[0].iov_base
);
1204 int blk_ioctl(BlockBackend
*blk
, unsigned long int req
, void *buf
)
1206 return blk_prw(blk
, req
, buf
, 0, blk_ioctl_entry
, 0);
1209 static void blk_aio_ioctl_entry(void *opaque
)
1211 BlkAioEmAIOCB
*acb
= opaque
;
1212 BlkRwCo
*rwco
= &acb
->rwco
;
1214 rwco
->ret
= blk_co_ioctl(rwco
->blk
, rwco
->offset
,
1215 rwco
->qiov
->iov
[0].iov_base
);
1216 blk_aio_complete(acb
);
1219 BlockAIOCB
*blk_aio_ioctl(BlockBackend
*blk
, unsigned long int req
, void *buf
,
1220 BlockCompletionFunc
*cb
, void *opaque
)
1225 iov
= (struct iovec
) {
1229 qemu_iovec_init_external(&qiov
, &iov
, 1);
1231 return blk_aio_prwv(blk
, req
, 0, &qiov
, blk_aio_ioctl_entry
, 0, cb
, opaque
);
1234 int blk_co_pdiscard(BlockBackend
*blk
, int64_t offset
, int count
)
1236 int ret
= blk_check_byte_request(blk
, offset
, count
);
1241 return bdrv_co_pdiscard(blk_bs(blk
), offset
, count
);
1244 int blk_co_flush(BlockBackend
*blk
)
1246 if (!blk_is_available(blk
)) {
1250 return bdrv_co_flush(blk_bs(blk
));
1253 static void blk_flush_entry(void *opaque
)
1255 BlkRwCo
*rwco
= opaque
;
1256 rwco
->ret
= blk_co_flush(rwco
->blk
);
1259 int blk_flush(BlockBackend
*blk
)
1261 return blk_prw(blk
, 0, NULL
, 0, blk_flush_entry
, 0);
1264 void blk_drain(BlockBackend
*blk
)
1267 bdrv_drain(blk_bs(blk
));
1271 void blk_drain_all(void)
1276 void blk_set_on_error(BlockBackend
*blk
, BlockdevOnError on_read_error
,
1277 BlockdevOnError on_write_error
)
1279 blk
->on_read_error
= on_read_error
;
1280 blk
->on_write_error
= on_write_error
;
1283 BlockdevOnError
blk_get_on_error(BlockBackend
*blk
, bool is_read
)
1285 return is_read
? blk
->on_read_error
: blk
->on_write_error
;
1288 BlockErrorAction
blk_get_error_action(BlockBackend
*blk
, bool is_read
,
1291 BlockdevOnError on_err
= blk_get_on_error(blk
, is_read
);
1294 case BLOCKDEV_ON_ERROR_ENOSPC
:
1295 return (error
== ENOSPC
) ?
1296 BLOCK_ERROR_ACTION_STOP
: BLOCK_ERROR_ACTION_REPORT
;
1297 case BLOCKDEV_ON_ERROR_STOP
:
1298 return BLOCK_ERROR_ACTION_STOP
;
1299 case BLOCKDEV_ON_ERROR_REPORT
:
1300 return BLOCK_ERROR_ACTION_REPORT
;
1301 case BLOCKDEV_ON_ERROR_IGNORE
:
1302 return BLOCK_ERROR_ACTION_IGNORE
;
1303 case BLOCKDEV_ON_ERROR_AUTO
:
1309 static void send_qmp_error_event(BlockBackend
*blk
,
1310 BlockErrorAction action
,
1311 bool is_read
, int error
)
1313 IoOperationType optype
;
1315 optype
= is_read
? IO_OPERATION_TYPE_READ
: IO_OPERATION_TYPE_WRITE
;
1316 qapi_event_send_block_io_error(blk_name(blk
),
1317 bdrv_get_node_name(blk_bs(blk
)), optype
,
1318 action
, blk_iostatus_is_enabled(blk
),
1319 error
== ENOSPC
, strerror(error
),
1323 /* This is done by device models because, while the block layer knows
1324 * about the error, it does not know whether an operation comes from
1325 * the device or the block layer (from a job, for example).
1327 void blk_error_action(BlockBackend
*blk
, BlockErrorAction action
,
1328 bool is_read
, int error
)
1332 if (action
== BLOCK_ERROR_ACTION_STOP
) {
1333 /* First set the iostatus, so that "info block" returns an iostatus
1334 * that matches the events raised so far (an additional error iostatus
1335 * is fine, but not a lost one).
1337 blk_iostatus_set_err(blk
, error
);
1339 /* Then raise the request to stop the VM and the event.
1340 * qemu_system_vmstop_request_prepare has two effects. First,
1341 * it ensures that the STOP event always comes after the
1342 * BLOCK_IO_ERROR event. Second, it ensures that even if management
1343 * can observe the STOP event and do a "cont" before the STOP
1344 * event is issued, the VM will not stop. In this case, vm_start()
1345 * also ensures that the STOP/RESUME pair of events is emitted.
1347 qemu_system_vmstop_request_prepare();
1348 send_qmp_error_event(blk
, action
, is_read
, error
);
1349 qemu_system_vmstop_request(RUN_STATE_IO_ERROR
);
1351 send_qmp_error_event(blk
, action
, is_read
, error
);
1355 int blk_is_read_only(BlockBackend
*blk
)
1357 BlockDriverState
*bs
= blk_bs(blk
);
1360 return bdrv_is_read_only(bs
);
1362 return blk
->root_state
.read_only
;
1366 int blk_is_sg(BlockBackend
*blk
)
1368 BlockDriverState
*bs
= blk_bs(blk
);
1374 return bdrv_is_sg(bs
);
1377 int blk_enable_write_cache(BlockBackend
*blk
)
1379 return blk
->enable_write_cache
;
1382 void blk_set_enable_write_cache(BlockBackend
*blk
, bool wce
)
1384 blk
->enable_write_cache
= wce
;
1387 void blk_invalidate_cache(BlockBackend
*blk
, Error
**errp
)
1389 BlockDriverState
*bs
= blk_bs(blk
);
1392 error_setg(errp
, "Device '%s' has no medium", blk
->name
);
1396 bdrv_invalidate_cache(bs
, errp
);
1399 bool blk_is_inserted(BlockBackend
*blk
)
1401 BlockDriverState
*bs
= blk_bs(blk
);
1403 return bs
&& bdrv_is_inserted(bs
);
1406 bool blk_is_available(BlockBackend
*blk
)
1408 return blk_is_inserted(blk
) && !blk_dev_is_tray_open(blk
);
1411 void blk_lock_medium(BlockBackend
*blk
, bool locked
)
1413 BlockDriverState
*bs
= blk_bs(blk
);
1416 bdrv_lock_medium(bs
, locked
);
1420 void blk_eject(BlockBackend
*blk
, bool eject_flag
)
1422 BlockDriverState
*bs
= blk_bs(blk
);
1425 /* blk_eject is only called by qdevified devices */
1426 assert(!blk
->legacy_dev
);
1429 bdrv_eject(bs
, eject_flag
);
1432 /* Whether or not we ejected on the backend,
1433 * the frontend experienced a tray event. */
1434 id
= blk_get_attached_dev_id(blk
);
1435 qapi_event_send_device_tray_moved(blk_name(blk
), id
,
1436 eject_flag
, &error_abort
);
1440 int blk_get_flags(BlockBackend
*blk
)
1442 BlockDriverState
*bs
= blk_bs(blk
);
1445 return bdrv_get_flags(bs
);
1447 return blk
->root_state
.open_flags
;
1451 /* Returns the maximum transfer length, in bytes; guaranteed nonzero */
1452 uint32_t blk_get_max_transfer(BlockBackend
*blk
)
1454 BlockDriverState
*bs
= blk_bs(blk
);
1458 max
= bs
->bl
.max_transfer
;
1460 return MIN_NON_ZERO(max
, INT_MAX
);
1463 int blk_get_max_iov(BlockBackend
*blk
)
1465 return blk
->root
->bs
->bl
.max_iov
;
1468 void blk_set_guest_block_size(BlockBackend
*blk
, int align
)
1470 blk
->guest_block_size
= align
;
1473 void *blk_try_blockalign(BlockBackend
*blk
, size_t size
)
1475 return qemu_try_blockalign(blk
? blk_bs(blk
) : NULL
, size
);
1478 void *blk_blockalign(BlockBackend
*blk
, size_t size
)
1480 return qemu_blockalign(blk
? blk_bs(blk
) : NULL
, size
);
1483 bool blk_op_is_blocked(BlockBackend
*blk
, BlockOpType op
, Error
**errp
)
1485 BlockDriverState
*bs
= blk_bs(blk
);
1491 return bdrv_op_is_blocked(bs
, op
, errp
);
1494 void blk_op_unblock(BlockBackend
*blk
, BlockOpType op
, Error
*reason
)
1496 BlockDriverState
*bs
= blk_bs(blk
);
1499 bdrv_op_unblock(bs
, op
, reason
);
1503 void blk_op_block_all(BlockBackend
*blk
, Error
*reason
)
1505 BlockDriverState
*bs
= blk_bs(blk
);
1508 bdrv_op_block_all(bs
, reason
);
1512 void blk_op_unblock_all(BlockBackend
*blk
, Error
*reason
)
1514 BlockDriverState
*bs
= blk_bs(blk
);
1517 bdrv_op_unblock_all(bs
, reason
);
1521 AioContext
*blk_get_aio_context(BlockBackend
*blk
)
1523 BlockDriverState
*bs
= blk_bs(blk
);
1526 return bdrv_get_aio_context(bs
);
1528 return qemu_get_aio_context();
1532 static AioContext
*blk_aiocb_get_aio_context(BlockAIOCB
*acb
)
1534 BlockBackendAIOCB
*blk_acb
= DO_UPCAST(BlockBackendAIOCB
, common
, acb
);
1535 return blk_get_aio_context(blk_acb
->blk
);
1538 void blk_set_aio_context(BlockBackend
*blk
, AioContext
*new_context
)
1540 BlockDriverState
*bs
= blk_bs(blk
);
1543 if (blk
->public.throttle_state
) {
1544 throttle_timers_detach_aio_context(&blk
->public.throttle_timers
);
1546 bdrv_set_aio_context(bs
, new_context
);
1547 if (blk
->public.throttle_state
) {
1548 throttle_timers_attach_aio_context(&blk
->public.throttle_timers
,
1554 void blk_add_aio_context_notifier(BlockBackend
*blk
,
1555 void (*attached_aio_context
)(AioContext
*new_context
, void *opaque
),
1556 void (*detach_aio_context
)(void *opaque
), void *opaque
)
1558 BlockDriverState
*bs
= blk_bs(blk
);
1561 bdrv_add_aio_context_notifier(bs
, attached_aio_context
,
1562 detach_aio_context
, opaque
);
1566 void blk_remove_aio_context_notifier(BlockBackend
*blk
,
1567 void (*attached_aio_context
)(AioContext
*,
1569 void (*detach_aio_context
)(void *),
1572 BlockDriverState
*bs
= blk_bs(blk
);
1575 bdrv_remove_aio_context_notifier(bs
, attached_aio_context
,
1576 detach_aio_context
, opaque
);
1580 void blk_add_remove_bs_notifier(BlockBackend
*blk
, Notifier
*notify
)
1582 notifier_list_add(&blk
->remove_bs_notifiers
, notify
);
1585 void blk_add_insert_bs_notifier(BlockBackend
*blk
, Notifier
*notify
)
1587 notifier_list_add(&blk
->insert_bs_notifiers
, notify
);
1590 void blk_io_plug(BlockBackend
*blk
)
1592 BlockDriverState
*bs
= blk_bs(blk
);
1599 void blk_io_unplug(BlockBackend
*blk
)
1601 BlockDriverState
*bs
= blk_bs(blk
);
1608 BlockAcctStats
*blk_get_stats(BlockBackend
*blk
)
1613 void *blk_aio_get(const AIOCBInfo
*aiocb_info
, BlockBackend
*blk
,
1614 BlockCompletionFunc
*cb
, void *opaque
)
1616 return qemu_aio_get(aiocb_info
, blk_bs(blk
), cb
, opaque
);
1619 int coroutine_fn
blk_co_pwrite_zeroes(BlockBackend
*blk
, int64_t offset
,
1620 int count
, BdrvRequestFlags flags
)
1622 return blk_co_pwritev(blk
, offset
, count
, NULL
,
1623 flags
| BDRV_REQ_ZERO_WRITE
);
1626 int blk_pwrite_compressed(BlockBackend
*blk
, int64_t offset
, const void *buf
,
1629 return blk_prw(blk
, offset
, (void *) buf
, count
, blk_write_entry
,
1630 BDRV_REQ_WRITE_COMPRESSED
);
1633 int blk_truncate(BlockBackend
*blk
, int64_t offset
)
1635 if (!blk_is_available(blk
)) {
1639 return bdrv_truncate(blk
->root
, offset
);
1642 static void blk_pdiscard_entry(void *opaque
)
1644 BlkRwCo
*rwco
= opaque
;
1645 rwco
->ret
= blk_co_pdiscard(rwco
->blk
, rwco
->offset
, rwco
->qiov
->size
);
1648 int blk_pdiscard(BlockBackend
*blk
, int64_t offset
, int count
)
1650 return blk_prw(blk
, offset
, NULL
, count
, blk_pdiscard_entry
, 0);
1653 int blk_save_vmstate(BlockBackend
*blk
, const uint8_t *buf
,
1654 int64_t pos
, int size
)
1658 if (!blk_is_available(blk
)) {
1662 ret
= bdrv_save_vmstate(blk_bs(blk
), buf
, pos
, size
);
1667 if (ret
== size
&& !blk
->enable_write_cache
) {
1668 ret
= bdrv_flush(blk_bs(blk
));
1671 return ret
< 0 ? ret
: size
;
1674 int blk_load_vmstate(BlockBackend
*blk
, uint8_t *buf
, int64_t pos
, int size
)
1676 if (!blk_is_available(blk
)) {
1680 return bdrv_load_vmstate(blk_bs(blk
), buf
, pos
, size
);
1683 int blk_probe_blocksizes(BlockBackend
*blk
, BlockSizes
*bsz
)
1685 if (!blk_is_available(blk
)) {
1689 return bdrv_probe_blocksizes(blk_bs(blk
), bsz
);
1692 int blk_probe_geometry(BlockBackend
*blk
, HDGeometry
*geo
)
1694 if (!blk_is_available(blk
)) {
1698 return bdrv_probe_geometry(blk_bs(blk
), geo
);
1702 * Updates the BlockBackendRootState object with data from the currently
1703 * attached BlockDriverState.
1705 void blk_update_root_state(BlockBackend
*blk
)
1709 blk
->root_state
.open_flags
= blk
->root
->bs
->open_flags
;
1710 blk
->root_state
.read_only
= blk
->root
->bs
->read_only
;
1711 blk
->root_state
.detect_zeroes
= blk
->root
->bs
->detect_zeroes
;
1715 * Returns the detect-zeroes setting to be used for bdrv_open() of a
1716 * BlockDriverState which is supposed to inherit the root state.
1718 bool blk_get_detect_zeroes_from_root_state(BlockBackend
*blk
)
1720 return blk
->root_state
.detect_zeroes
;
1724 * Returns the flags to be used for bdrv_open() of a BlockDriverState which is
1725 * supposed to inherit the root state.
1727 int blk_get_open_flags_from_root_state(BlockBackend
*blk
)
1731 bs_flags
= blk
->root_state
.read_only
? 0 : BDRV_O_RDWR
;
1732 bs_flags
|= blk
->root_state
.open_flags
& ~BDRV_O_RDWR
;
1737 BlockBackendRootState
*blk_get_root_state(BlockBackend
*blk
)
1739 return &blk
->root_state
;
1742 int blk_commit_all(void)
1744 BlockBackend
*blk
= NULL
;
1746 while ((blk
= blk_all_next(blk
)) != NULL
) {
1747 AioContext
*aio_context
= blk_get_aio_context(blk
);
1749 aio_context_acquire(aio_context
);
1750 if (blk_is_inserted(blk
) && blk
->root
->bs
->backing
) {
1751 int ret
= bdrv_commit(blk
->root
->bs
);
1753 aio_context_release(aio_context
);
1757 aio_context_release(aio_context
);
1763 /* throttling disk I/O limits */
1764 void blk_set_io_limits(BlockBackend
*blk
, ThrottleConfig
*cfg
)
1766 throttle_group_config(blk
, cfg
);
1769 void blk_io_limits_disable(BlockBackend
*blk
)
1771 assert(blk
->public.throttle_state
);
1772 bdrv_drained_begin(blk_bs(blk
));
1773 throttle_group_unregister_blk(blk
);
1774 bdrv_drained_end(blk_bs(blk
));
1777 /* should be called before blk_set_io_limits if a limit is set */
1778 void blk_io_limits_enable(BlockBackend
*blk
, const char *group
)
1780 assert(!blk
->public.throttle_state
);
1781 throttle_group_register_blk(blk
, group
);
1784 void blk_io_limits_update_group(BlockBackend
*blk
, const char *group
)
1786 /* this BB is not part of any group */
1787 if (!blk
->public.throttle_state
) {
1791 /* this BB is a part of the same group than the one we want */
1792 if (!g_strcmp0(throttle_group_get_name(blk
), group
)) {
1796 /* need to change the group this bs belong to */
1797 blk_io_limits_disable(blk
);
1798 blk_io_limits_enable(blk
, group
);
1801 static void blk_root_drained_begin(BdrvChild
*child
)
1803 BlockBackend
*blk
= child
->opaque
;
1805 /* Note that blk->root may not be accessible here yet if we are just
1806 * attaching to a BlockDriverState that is drained. Use child instead. */
1808 if (blk
->public.io_limits_disabled
++ == 0) {
1809 throttle_group_restart_blk(blk
);
1813 static void blk_root_drained_end(BdrvChild
*child
)
1815 BlockBackend
*blk
= child
->opaque
;
1817 assert(blk
->public.io_limits_disabled
);
1818 --blk
->public.io_limits_disabled
;