xref: /qemu/include/block/block_int.h (revision 14b61600)
1 /*
2  * QEMU System Emulator block driver
3  *
4  * Copyright (c) 2003 Fabrice Bellard
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 #ifndef BLOCK_INT_H
25 #define BLOCK_INT_H
26 
27 #include "block/accounting.h"
28 #include "block/block.h"
29 #include "block/throttle-groups.h"
30 #include "qemu/option.h"
31 #include "qemu/queue.h"
32 #include "qemu/coroutine.h"
33 #include "qemu/timer.h"
34 #include "qapi-types.h"
35 #include "qemu/hbitmap.h"
36 #include "block/snapshot.h"
37 #include "qemu/main-loop.h"
38 #include "qemu/throttle.h"
39 
40 #define BLOCK_FLAG_ENCRYPT          1
41 #define BLOCK_FLAG_COMPAT6          4
42 #define BLOCK_FLAG_LAZY_REFCOUNTS   8
43 
44 #define BLOCK_OPT_SIZE              "size"
45 #define BLOCK_OPT_ENCRYPT           "encryption"
46 #define BLOCK_OPT_COMPAT6           "compat6"
47 #define BLOCK_OPT_BACKING_FILE      "backing_file"
48 #define BLOCK_OPT_BACKING_FMT       "backing_fmt"
49 #define BLOCK_OPT_CLUSTER_SIZE      "cluster_size"
50 #define BLOCK_OPT_TABLE_SIZE        "table_size"
51 #define BLOCK_OPT_PREALLOC          "preallocation"
52 #define BLOCK_OPT_SUBFMT            "subformat"
53 #define BLOCK_OPT_COMPAT_LEVEL      "compat"
54 #define BLOCK_OPT_LAZY_REFCOUNTS    "lazy_refcounts"
55 #define BLOCK_OPT_ADAPTER_TYPE      "adapter_type"
56 #define BLOCK_OPT_REDUNDANCY        "redundancy"
57 #define BLOCK_OPT_NOCOW             "nocow"
58 #define BLOCK_OPT_OBJECT_SIZE       "object_size"
59 #define BLOCK_OPT_REFCOUNT_BITS     "refcount_bits"
60 
61 #define BLOCK_PROBE_BUF_SIZE        512
62 
63 typedef struct BdrvTrackedRequest {
64     BlockDriverState *bs;
65     int64_t offset;
66     unsigned int bytes;
67     bool is_write;
68 
69     bool serialising;
70     int64_t overlap_offset;
71     unsigned int overlap_bytes;
72 
73     QLIST_ENTRY(BdrvTrackedRequest) list;
74     Coroutine *co; /* owner, used for deadlock detection */
75     CoQueue wait_queue; /* coroutines blocked on this request */
76 
77     struct BdrvTrackedRequest *waiting_for;
78 } BdrvTrackedRequest;
79 
80 struct BlockDriver {
81     const char *format_name;
82     int instance_size;
83 
84     /* set to true if the BlockDriver is a block filter */
85     bool is_filter;
86     /* for snapshots block filter like Quorum can implement the
87      * following recursive callback.
88      * It's purpose is to recurse on the filter children while calling
89      * bdrv_recurse_is_first_non_filter on them.
90      * For a sample implementation look in the future Quorum block filter.
91      */
92     bool (*bdrv_recurse_is_first_non_filter)(BlockDriverState *bs,
93                                              BlockDriverState *candidate);
94 
95     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
96     int (*bdrv_probe_device)(const char *filename);
97 
98     /* Any driver implementing this callback is expected to be able to handle
99      * NULL file names in its .bdrv_open() implementation */
100     void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp);
101     /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have
102      * this field set to true, except ones that are defined only by their
103      * child's bs.
104      * An example of the last type will be the quorum block driver.
105      */
106     bool bdrv_needs_filename;
107 
108     /* Set if a driver can support backing files */
109     bool supports_backing;
110 
111     /* For handling image reopen for split or non-split files */
112     int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,
113                                BlockReopenQueue *queue, Error **errp);
114     void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);
115     void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state);
116 
117     int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags,
118                      Error **errp);
119     int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags,
120                           Error **errp);
121     int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
122                      uint8_t *buf, int nb_sectors);
123     int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
124                       const uint8_t *buf, int nb_sectors);
125     void (*bdrv_close)(BlockDriverState *bs);
126     int (*bdrv_create)(const char *filename, QemuOpts *opts, Error **errp);
127     int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
128     int (*bdrv_make_empty)(BlockDriverState *bs);
129 
130     void (*bdrv_refresh_filename)(BlockDriverState *bs);
131 
132     /* aio */
133     BlockAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
134         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
135         BlockCompletionFunc *cb, void *opaque);
136     BlockAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
137         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
138         BlockCompletionFunc *cb, void *opaque);
139     BlockAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
140         BlockCompletionFunc *cb, void *opaque);
141     BlockAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs,
142         int64_t sector_num, int nb_sectors,
143         BlockCompletionFunc *cb, void *opaque);
144 
145     int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
146         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
147     int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
148         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
149     /*
150      * Efficiently zero a region of the disk image.  Typically an image format
151      * would use a compact metadata representation to implement this.  This
152      * function pointer may be NULL and .bdrv_co_writev() will be called
153      * instead.
154      */
155     int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs,
156         int64_t sector_num, int nb_sectors, BdrvRequestFlags flags);
157     int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
158         int64_t sector_num, int nb_sectors);
159     int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs,
160         int64_t sector_num, int nb_sectors, int *pnum);
161 
162     /*
163      * Invalidate any cached meta-data.
164      */
165     void (*bdrv_invalidate_cache)(BlockDriverState *bs, Error **errp);
166 
167     /*
168      * Flushes all data that was already written to the OS all the way down to
169      * the disk (for example raw-posix calls fsync()).
170      */
171     int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
172 
173     /*
174      * Flushes all internal caches to the OS. The data may still sit in a
175      * writeback cache of the host OS, but it will survive a crash of the qemu
176      * process.
177      */
178     int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
179 
180     const char *protocol_name;
181     int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
182 
183     int64_t (*bdrv_getlength)(BlockDriverState *bs);
184     bool has_variable_length;
185     int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
186 
187     int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
188                                  const uint8_t *buf, int nb_sectors);
189 
190     int (*bdrv_snapshot_create)(BlockDriverState *bs,
191                                 QEMUSnapshotInfo *sn_info);
192     int (*bdrv_snapshot_goto)(BlockDriverState *bs,
193                               const char *snapshot_id);
194     int (*bdrv_snapshot_delete)(BlockDriverState *bs,
195                                 const char *snapshot_id,
196                                 const char *name,
197                                 Error **errp);
198     int (*bdrv_snapshot_list)(BlockDriverState *bs,
199                               QEMUSnapshotInfo **psn_info);
200     int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
201                                   const char *snapshot_id,
202                                   const char *name,
203                                   Error **errp);
204     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
205     ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs);
206 
207     int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov,
208                              int64_t pos);
209     int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
210                              int64_t pos, int size);
211 
212     int (*bdrv_change_backing_file)(BlockDriverState *bs,
213         const char *backing_file, const char *backing_fmt);
214 
215     /* removable device specific */
216     bool (*bdrv_is_inserted)(BlockDriverState *bs);
217     int (*bdrv_media_changed)(BlockDriverState *bs);
218     void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
219     void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
220 
221     /* to control generic scsi devices */
222     int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf);
223     BlockAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
224         unsigned long int req, void *buf,
225         BlockCompletionFunc *cb, void *opaque);
226 
227     /* List of options for creating images, terminated by name == NULL */
228     QemuOptsList *create_opts;
229 
230     /*
231      * Returns 0 for completed check, -errno for internal errors.
232      * The check results are stored in result.
233      */
234     int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result,
235         BdrvCheckMode fix);
236 
237     int (*bdrv_amend_options)(BlockDriverState *bs, QemuOpts *opts,
238                               BlockDriverAmendStatusCB *status_cb);
239 
240     void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event);
241 
242     /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
243     int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
244         const char *tag);
245     int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs,
246         const char *tag);
247     int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);
248     bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);
249 
250     void (*bdrv_refresh_limits)(BlockDriverState *bs, Error **errp);
251 
252     /*
253      * Returns 1 if newly created images are guaranteed to contain only
254      * zeros, 0 otherwise.
255      */
256     int (*bdrv_has_zero_init)(BlockDriverState *bs);
257 
258     /* Remove fd handlers, timers, and other event loop callbacks so the event
259      * loop is no longer in use.  Called with no in-flight requests and in
260      * depth-first traversal order with parents before child nodes.
261      */
262     void (*bdrv_detach_aio_context)(BlockDriverState *bs);
263 
264     /* Add fd handlers, timers, and other event loop callbacks so I/O requests
265      * can be processed again.  Called with no in-flight requests and in
266      * depth-first traversal order with child nodes before parent nodes.
267      */
268     void (*bdrv_attach_aio_context)(BlockDriverState *bs,
269                                     AioContext *new_context);
270 
271     /* io queue for linux-aio */
272     void (*bdrv_io_plug)(BlockDriverState *bs);
273     void (*bdrv_io_unplug)(BlockDriverState *bs);
274     void (*bdrv_flush_io_queue)(BlockDriverState *bs);
275 
276     /**
277      * Try to get @bs's logical and physical block size.
278      * On success, store them in @bsz and return zero.
279      * On failure, return negative errno.
280      */
281     int (*bdrv_probe_blocksizes)(BlockDriverState *bs, BlockSizes *bsz);
282     /**
283      * Try to get @bs's geometry (cyls, heads, sectors)
284      * On success, store them in @geo and return 0.
285      * On failure return -errno.
286      * Only drivers that want to override guest geometry implement this
287      * callback; see hd_geometry_guess().
288      */
289     int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo);
290 
291     QLIST_ENTRY(BlockDriver) list;
292 };
293 
294 typedef struct BlockLimits {
295     /* maximum number of sectors that can be discarded at once */
296     int max_discard;
297 
298     /* optimal alignment for discard requests in sectors */
299     int64_t discard_alignment;
300 
301     /* maximum number of sectors that can zeroized at once */
302     int max_write_zeroes;
303 
304     /* optimal alignment for write zeroes requests in sectors */
305     int64_t write_zeroes_alignment;
306 
307     /* optimal transfer length in sectors */
308     int opt_transfer_length;
309 
310     /* maximal transfer length in sectors */
311     int max_transfer_length;
312 
313     /* memory alignment so that no bounce buffer is needed */
314     size_t min_mem_alignment;
315 
316     /* memory alignment for bounce buffer */
317     size_t opt_mem_alignment;
318 } BlockLimits;
319 
320 typedef struct BdrvOpBlocker BdrvOpBlocker;
321 
322 typedef struct BdrvAioNotifier {
323     void (*attached_aio_context)(AioContext *new_context, void *opaque);
324     void (*detach_aio_context)(void *opaque);
325 
326     void *opaque;
327 
328     QLIST_ENTRY(BdrvAioNotifier) list;
329 } BdrvAioNotifier;
330 
331 struct BdrvChildRole {
332     int (*inherit_flags)(int parent_flags);
333 };
334 
335 extern const BdrvChildRole child_file;
336 extern const BdrvChildRole child_format;
337 
338 struct BdrvChild {
339     BlockDriverState *bs;
340     const BdrvChildRole *role;
341     QLIST_ENTRY(BdrvChild) next;
342     QLIST_ENTRY(BdrvChild) next_parent;
343 };
344 
345 /*
346  * Note: the function bdrv_append() copies and swaps contents of
347  * BlockDriverStates, so if you add new fields to this struct, please
348  * inspect bdrv_append() to determine if the new fields need to be
349  * copied as well.
350  */
351 struct BlockDriverState {
352     int64_t total_sectors; /* if we are reading a disk image, give its
353                               size in sectors */
354     int read_only; /* if true, the media is read only */
355     int open_flags; /* flags used to open the file, re-used for re-open */
356     int encrypted; /* if true, the media is encrypted */
357     int valid_key; /* if true, a valid encryption key has been set */
358     int sg;        /* if true, the device is a /dev/sg* */
359     int copy_on_read; /* if true, copy read backing sectors into image
360                          note this is a reference count */
361     bool probed;
362 
363     BlockDriver *drv; /* NULL means no media */
364     void *opaque;
365 
366     BlockBackend *blk;          /* owning backend, if any */
367 
368     AioContext *aio_context; /* event loop used for fd handlers, timers, etc */
369     /* long-running tasks intended to always use the same AioContext as this
370      * BDS may register themselves in this list to be notified of changes
371      * regarding this BDS's context */
372     QLIST_HEAD(, BdrvAioNotifier) aio_notifiers;
373 
374     char filename[PATH_MAX];
375     char backing_file[PATH_MAX]; /* if non zero, the image is a diff of
376                                     this file image */
377     char backing_format[16]; /* if non-zero and backing_file exists */
378 
379     QDict *full_open_options;
380     char exact_filename[PATH_MAX];
381 
382     BdrvChild *backing;
383     BdrvChild *file;
384 
385     NotifierList close_notifiers;
386 
387     /* Callback before write request is processed */
388     NotifierWithReturnList before_write_notifiers;
389 
390     /* number of in-flight serialising requests */
391     unsigned int serialising_in_flight;
392 
393     /* I/O throttling */
394     CoQueue      throttled_reqs[2];
395     bool         io_limits_enabled;
396     /* The following fields are protected by the ThrottleGroup lock.
397      * See the ThrottleGroup documentation for details. */
398     ThrottleState *throttle_state;
399     ThrottleTimers throttle_timers;
400     unsigned       pending_reqs[2];
401     QLIST_ENTRY(BlockDriverState) round_robin;
402 
403     /* Offset after the highest byte written to */
404     uint64_t wr_highest_offset;
405 
406     /* I/O Limits */
407     BlockLimits bl;
408 
409     /* Whether produces zeros when read beyond eof */
410     bool zero_beyond_eof;
411 
412     /* Alignment requirement for offset/length of I/O requests */
413     unsigned int request_alignment;
414 
415     /* do we need to tell the quest if we have a volatile write cache? */
416     int enable_write_cache;
417 
418     /* the following member gives a name to every node on the bs graph. */
419     char node_name[32];
420     /* element of the list of named nodes building the graph */
421     QTAILQ_ENTRY(BlockDriverState) node_list;
422     /* element of the list of "drives" the guest sees */
423     QTAILQ_ENTRY(BlockDriverState) device_list;
424     QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
425     int refcnt;
426 
427     QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
428 
429     /* operation blockers */
430     QLIST_HEAD(, BdrvOpBlocker) op_blockers[BLOCK_OP_TYPE_MAX];
431 
432     /* long-running background operation */
433     BlockJob *job;
434 
435     /* The node that this node inherited default options from (and a reopen on
436      * which can affect this node by changing these defaults). This is always a
437      * parent node of this node. */
438     BlockDriverState *inherits_from;
439     QLIST_HEAD(, BdrvChild) children;
440     QLIST_HEAD(, BdrvChild) parents;
441 
442     QDict *options;
443     BlockdevDetectZeroesOptions detect_zeroes;
444 
445     /* The error object in use for blocking operations on backing_hd */
446     Error *backing_blocker;
447 
448     /* threshold limit for writes, in bytes. "High water mark". */
449     uint64_t write_threshold_offset;
450     NotifierWithReturn write_threshold_notifier;
451 
452     int quiesce_counter;
453 };
454 
455 struct BlockBackendRootState {
456     int open_flags;
457     bool read_only;
458     BlockdevDetectZeroesOptions detect_zeroes;
459 
460     char *throttle_group;
461     ThrottleState *throttle_state;
462 };
463 
464 static inline BlockDriverState *backing_bs(BlockDriverState *bs)
465 {
466     return bs->backing ? bs->backing->bs : NULL;
467 }
468 
469 
470 /* Essential block drivers which must always be statically linked into qemu, and
471  * which therefore can be accessed without using bdrv_find_format() */
472 extern BlockDriver bdrv_file;
473 extern BlockDriver bdrv_raw;
474 extern BlockDriver bdrv_qcow2;
475 
476 /**
477  * bdrv_setup_io_funcs:
478  *
479  * Prepare a #BlockDriver for I/O request processing by populating
480  * unimplemented coroutine and AIO interfaces with generic wrapper functions
481  * that fall back to implemented interfaces.
482  */
483 void bdrv_setup_io_funcs(BlockDriver *bdrv);
484 
485 int get_tmp_filename(char *filename, int size);
486 BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
487                             const char *filename);
488 
489 void bdrv_set_io_limits(BlockDriverState *bs,
490                         ThrottleConfig *cfg);
491 
492 
493 /**
494  * bdrv_add_before_write_notifier:
495  *
496  * Register a callback that is invoked before write requests are processed but
497  * after any throttling or waiting for overlapping requests.
498  */
499 void bdrv_add_before_write_notifier(BlockDriverState *bs,
500                                     NotifierWithReturn *notifier);
501 
502 /**
503  * bdrv_detach_aio_context:
504  *
505  * May be called from .bdrv_detach_aio_context() to detach children from the
506  * current #AioContext.  This is only needed by block drivers that manage their
507  * own children.  Both ->file and ->backing are automatically handled and
508  * block drivers should not call this function on them explicitly.
509  */
510 void bdrv_detach_aio_context(BlockDriverState *bs);
511 
512 /**
513  * bdrv_attach_aio_context:
514  *
515  * May be called from .bdrv_attach_aio_context() to attach children to the new
516  * #AioContext.  This is only needed by block drivers that manage their own
517  * children.  Both ->file and ->backing are automatically handled and block
518  * drivers should not call this function on them explicitly.
519  */
520 void bdrv_attach_aio_context(BlockDriverState *bs,
521                              AioContext *new_context);
522 
523 /**
524  * bdrv_add_aio_context_notifier:
525  *
526  * If a long-running job intends to be always run in the same AioContext as a
527  * certain BDS, it may use this function to be notified of changes regarding the
528  * association of the BDS to an AioContext.
529  *
530  * attached_aio_context() is called after the target BDS has been attached to a
531  * new AioContext; detach_aio_context() is called before the target BDS is being
532  * detached from its old AioContext.
533  */
534 void bdrv_add_aio_context_notifier(BlockDriverState *bs,
535         void (*attached_aio_context)(AioContext *new_context, void *opaque),
536         void (*detach_aio_context)(void *opaque), void *opaque);
537 
538 /**
539  * bdrv_remove_aio_context_notifier:
540  *
541  * Unsubscribe of change notifications regarding the BDS's AioContext. The
542  * parameters given here have to be the same as those given to
543  * bdrv_add_aio_context_notifier().
544  */
545 void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
546                                       void (*aio_context_attached)(AioContext *,
547                                                                    void *),
548                                       void (*aio_context_detached)(void *),
549                                       void *opaque);
550 
551 #ifdef _WIN32
552 int is_windows_drive(const char *filename);
553 #endif
554 
555 /**
556  * stream_start:
557  * @bs: Block device to operate on.
558  * @base: Block device that will become the new base, or %NULL to
559  * flatten the whole backing file chain onto @bs.
560  * @base_id: The file name that will be written to @bs as the new
561  * backing file if the job completes.  Ignored if @base is %NULL.
562  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
563  * @on_error: The action to take upon error.
564  * @cb: Completion function for the job.
565  * @opaque: Opaque pointer value passed to @cb.
566  * @errp: Error object.
567  *
568  * Start a streaming operation on @bs.  Clusters that are unallocated
569  * in @bs, but allocated in any image between @base and @bs (both
570  * exclusive) will be written to @bs.  At the end of a successful
571  * streaming job, the backing file of @bs will be changed to
572  * @base_id in the written image and to @base in the live BlockDriverState.
573  */
574 void stream_start(BlockDriverState *bs, BlockDriverState *base,
575                   const char *base_id, int64_t speed, BlockdevOnError on_error,
576                   BlockCompletionFunc *cb,
577                   void *opaque, Error **errp);
578 
579 /**
580  * commit_start:
581  * @bs: Active block device.
582  * @top: Top block device to be committed.
583  * @base: Block device that will be written into, and become the new top.
584  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
585  * @on_error: The action to take upon error.
586  * @cb: Completion function for the job.
587  * @opaque: Opaque pointer value passed to @cb.
588  * @backing_file_str: String to use as the backing file in @top's overlay
589  * @errp: Error object.
590  *
591  */
592 void commit_start(BlockDriverState *bs, BlockDriverState *base,
593                  BlockDriverState *top, int64_t speed,
594                  BlockdevOnError on_error, BlockCompletionFunc *cb,
595                  void *opaque, const char *backing_file_str, Error **errp);
596 /**
597  * commit_active_start:
598  * @bs: Active block device to be committed.
599  * @base: Block device that will be written into, and become the new top.
600  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
601  * @on_error: The action to take upon error.
602  * @cb: Completion function for the job.
603  * @opaque: Opaque pointer value passed to @cb.
604  * @errp: Error object.
605  *
606  */
607 void commit_active_start(BlockDriverState *bs, BlockDriverState *base,
608                          int64_t speed,
609                          BlockdevOnError on_error,
610                          BlockCompletionFunc *cb,
611                          void *opaque, Error **errp);
612 /*
613  * mirror_start:
614  * @bs: Block device to operate on.
615  * @target: Block device to write to.
616  * @replaces: Block graph node name to replace once the mirror is done. Can
617  *            only be used when full mirroring is selected.
618  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
619  * @granularity: The chosen granularity for the dirty bitmap.
620  * @buf_size: The amount of data that can be in flight at one time.
621  * @mode: Whether to collapse all images in the chain to the target.
622  * @on_source_error: The action to take upon error reading from the source.
623  * @on_target_error: The action to take upon error writing to the target.
624  * @unmap: Whether to unmap target where source sectors only contain zeroes.
625  * @cb: Completion function for the job.
626  * @opaque: Opaque pointer value passed to @cb.
627  * @errp: Error object.
628  *
629  * Start a mirroring operation on @bs.  Clusters that are allocated
630  * in @bs will be written to @bs until the job is cancelled or
631  * manually completed.  At the end of a successful mirroring job,
632  * @bs will be switched to read from @target.
633  */
634 void mirror_start(BlockDriverState *bs, BlockDriverState *target,
635                   const char *replaces,
636                   int64_t speed, uint32_t granularity, int64_t buf_size,
637                   MirrorSyncMode mode, BlockdevOnError on_source_error,
638                   BlockdevOnError on_target_error,
639                   bool unmap,
640                   BlockCompletionFunc *cb,
641                   void *opaque, Error **errp);
642 
643 /*
644  * backup_start:
645  * @bs: Block device to operate on.
646  * @target: Block device to write to.
647  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
648  * @sync_mode: What parts of the disk image should be copied to the destination.
649  * @sync_bitmap: The dirty bitmap if sync_mode is MIRROR_SYNC_MODE_INCREMENTAL.
650  * @on_source_error: The action to take upon error reading from the source.
651  * @on_target_error: The action to take upon error writing to the target.
652  * @cb: Completion function for the job.
653  * @opaque: Opaque pointer value passed to @cb.
654  *
655  * Start a backup operation on @bs.  Clusters in @bs are written to @target
656  * until the job is cancelled or manually completed.
657  */
658 void backup_start(BlockDriverState *bs, BlockDriverState *target,
659                   int64_t speed, MirrorSyncMode sync_mode,
660                   BdrvDirtyBitmap *sync_bitmap,
661                   BlockdevOnError on_source_error,
662                   BlockdevOnError on_target_error,
663                   BlockCompletionFunc *cb, void *opaque,
664                   Error **errp);
665 
666 void blk_set_bs(BlockBackend *blk, BlockDriverState *bs);
667 
668 void blk_dev_change_media_cb(BlockBackend *blk, bool load);
669 bool blk_dev_has_removable_media(BlockBackend *blk);
670 void blk_dev_eject_request(BlockBackend *blk, bool force);
671 bool blk_dev_is_tray_open(BlockBackend *blk);
672 bool blk_dev_is_medium_locked(BlockBackend *blk);
673 void blk_dev_resize_cb(BlockBackend *blk);
674 
675 void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, int nr_sectors);
676 bool bdrv_requests_pending(BlockDriverState *bs);
677 
678 #endif /* BLOCK_INT_H */
679