xref: /openbmc/qemu/include/block/block_int.h (revision 77a8257e)
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 "qemu/option.h"
30 #include "qemu/queue.h"
31 #include "block/coroutine.h"
32 #include "qemu/timer.h"
33 #include "qapi-types.h"
34 #include "qapi/qmp/qerror.h"
35 #include "monitor/monitor.h"
36 #include "qemu/hbitmap.h"
37 #include "block/snapshot.h"
38 #include "qemu/main-loop.h"
39 #include "qemu/throttle.h"
40 
41 #define BLOCK_FLAG_ENCRYPT          1
42 #define BLOCK_FLAG_COMPAT6          4
43 #define BLOCK_FLAG_LAZY_REFCOUNTS   8
44 
45 #define BLOCK_OPT_SIZE              "size"
46 #define BLOCK_OPT_ENCRYPT           "encryption"
47 #define BLOCK_OPT_COMPAT6           "compat6"
48 #define BLOCK_OPT_BACKING_FILE      "backing_file"
49 #define BLOCK_OPT_BACKING_FMT       "backing_fmt"
50 #define BLOCK_OPT_CLUSTER_SIZE      "cluster_size"
51 #define BLOCK_OPT_TABLE_SIZE        "table_size"
52 #define BLOCK_OPT_PREALLOC          "preallocation"
53 #define BLOCK_OPT_SUBFMT            "subformat"
54 #define BLOCK_OPT_COMPAT_LEVEL      "compat"
55 #define BLOCK_OPT_LAZY_REFCOUNTS    "lazy_refcounts"
56 #define BLOCK_OPT_ADAPTER_TYPE      "adapter_type"
57 #define BLOCK_OPT_REDUNDANCY        "redundancy"
58 #define BLOCK_OPT_NOCOW             "nocow"
59 #define BLOCK_OPT_OBJECT_SIZE       "object_size"
60 #define BLOCK_OPT_REFCOUNT_BITS     "refcount_bits"
61 
62 #define BLOCK_PROBE_BUF_SIZE        512
63 
64 typedef struct BdrvTrackedRequest {
65     BlockDriverState *bs;
66     int64_t offset;
67     unsigned int bytes;
68     bool is_write;
69 
70     bool serialising;
71     int64_t overlap_offset;
72     unsigned int overlap_bytes;
73 
74     QLIST_ENTRY(BdrvTrackedRequest) list;
75     Coroutine *co; /* owner, used for deadlock detection */
76     CoQueue wait_queue; /* coroutines blocked on this request */
77 
78     struct BdrvTrackedRequest *waiting_for;
79 } BdrvTrackedRequest;
80 
81 struct BlockDriver {
82     const char *format_name;
83     int instance_size;
84 
85     /* set to true if the BlockDriver is a block filter */
86     bool is_filter;
87     /* for snapshots block filter like Quorum can implement the
88      * following recursive callback.
89      * It's purpose is to recurse on the filter children while calling
90      * bdrv_recurse_is_first_non_filter on them.
91      * For a sample implementation look in the future Quorum block filter.
92      */
93     bool (*bdrv_recurse_is_first_non_filter)(BlockDriverState *bs,
94                                              BlockDriverState *candidate);
95 
96     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
97     int (*bdrv_probe_device)(const char *filename);
98 
99     /* Any driver implementing this callback is expected to be able to handle
100      * NULL file names in its .bdrv_open() implementation */
101     void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp);
102     /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have
103      * this field set to true, except ones that are defined only by their
104      * child's bs.
105      * An example of the last type will be the quorum block driver.
106      */
107     bool bdrv_needs_filename;
108 
109     /* Set if a driver can support backing files */
110     bool supports_backing;
111 
112     /* For handling image reopen for split or non-split files */
113     int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,
114                                BlockReopenQueue *queue, Error **errp);
115     void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);
116     void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state);
117 
118     int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags,
119                      Error **errp);
120     int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags,
121                           Error **errp);
122     int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
123                      uint8_t *buf, int nb_sectors);
124     int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
125                       const uint8_t *buf, int nb_sectors);
126     void (*bdrv_close)(BlockDriverState *bs);
127     void (*bdrv_rebind)(BlockDriverState *bs);
128     int (*bdrv_create)(const char *filename, QemuOpts *opts, Error **errp);
129     int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
130     int (*bdrv_make_empty)(BlockDriverState *bs);
131 
132     void (*bdrv_refresh_filename)(BlockDriverState *bs);
133 
134     /* aio */
135     BlockAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
136         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
137         BlockCompletionFunc *cb, void *opaque);
138     BlockAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
139         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
140         BlockCompletionFunc *cb, void *opaque);
141     BlockAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
142         BlockCompletionFunc *cb, void *opaque);
143     BlockAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs,
144         int64_t sector_num, int nb_sectors,
145         BlockCompletionFunc *cb, void *opaque);
146 
147     int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
148         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
149     int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
150         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
151     /*
152      * Efficiently zero a region of the disk image.  Typically an image format
153      * would use a compact metadata representation to implement this.  This
154      * function pointer may be NULL and .bdrv_co_writev() will be called
155      * instead.
156      */
157     int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs,
158         int64_t sector_num, int nb_sectors, BdrvRequestFlags flags);
159     int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
160         int64_t sector_num, int nb_sectors);
161     int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs,
162         int64_t sector_num, int nb_sectors, int *pnum);
163 
164     /*
165      * Invalidate any cached meta-data.
166      */
167     void (*bdrv_invalidate_cache)(BlockDriverState *bs, Error **errp);
168 
169     /*
170      * Flushes all data that was already written to the OS all the way down to
171      * the disk (for example raw-posix calls fsync()).
172      */
173     int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
174 
175     /*
176      * Flushes all internal caches to the OS. The data may still sit in a
177      * writeback cache of the host OS, but it will survive a crash of the qemu
178      * process.
179      */
180     int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
181 
182     const char *protocol_name;
183     int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
184 
185     int64_t (*bdrv_getlength)(BlockDriverState *bs);
186     bool has_variable_length;
187     int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
188 
189     int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
190                                  const uint8_t *buf, int nb_sectors);
191 
192     int (*bdrv_snapshot_create)(BlockDriverState *bs,
193                                 QEMUSnapshotInfo *sn_info);
194     int (*bdrv_snapshot_goto)(BlockDriverState *bs,
195                               const char *snapshot_id);
196     int (*bdrv_snapshot_delete)(BlockDriverState *bs,
197                                 const char *snapshot_id,
198                                 const char *name,
199                                 Error **errp);
200     int (*bdrv_snapshot_list)(BlockDriverState *bs,
201                               QEMUSnapshotInfo **psn_info);
202     int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
203                                   const char *snapshot_id,
204                                   const char *name,
205                                   Error **errp);
206     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
207     ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs);
208 
209     int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov,
210                              int64_t pos);
211     int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
212                              int64_t pos, int size);
213 
214     int (*bdrv_change_backing_file)(BlockDriverState *bs,
215         const char *backing_file, const char *backing_fmt);
216 
217     /* removable device specific */
218     int (*bdrv_is_inserted)(BlockDriverState *bs);
219     int (*bdrv_media_changed)(BlockDriverState *bs);
220     void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
221     void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
222 
223     /* to control generic scsi devices */
224     int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf);
225     BlockAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
226         unsigned long int req, void *buf,
227         BlockCompletionFunc *cb, void *opaque);
228 
229     /* List of options for creating images, terminated by name == NULL */
230     QemuOptsList *create_opts;
231 
232     /*
233      * Returns 0 for completed check, -errno for internal errors.
234      * The check results are stored in result.
235      */
236     int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result,
237         BdrvCheckMode fix);
238 
239     int (*bdrv_amend_options)(BlockDriverState *bs, QemuOpts *opts,
240                               BlockDriverAmendStatusCB *status_cb);
241 
242     void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event);
243 
244     /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
245     int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
246         const char *tag);
247     int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs,
248         const char *tag);
249     int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);
250     bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);
251 
252     void (*bdrv_refresh_limits)(BlockDriverState *bs, Error **errp);
253 
254     /*
255      * Returns 1 if newly created images are guaranteed to contain only
256      * zeros, 0 otherwise.
257      */
258     int (*bdrv_has_zero_init)(BlockDriverState *bs);
259 
260     /* Remove fd handlers, timers, and other event loop callbacks so the event
261      * loop is no longer in use.  Called with no in-flight requests and in
262      * depth-first traversal order with parents before child nodes.
263      */
264     void (*bdrv_detach_aio_context)(BlockDriverState *bs);
265 
266     /* Add fd handlers, timers, and other event loop callbacks so I/O requests
267      * can be processed again.  Called with no in-flight requests and in
268      * depth-first traversal order with child nodes before parent nodes.
269      */
270     void (*bdrv_attach_aio_context)(BlockDriverState *bs,
271                                     AioContext *new_context);
272 
273     /* io queue for linux-aio */
274     void (*bdrv_io_plug)(BlockDriverState *bs);
275     void (*bdrv_io_unplug)(BlockDriverState *bs);
276     void (*bdrv_flush_io_queue)(BlockDriverState *bs);
277 
278     /**
279      * Try to get @bs's logical and physical block size.
280      * On success, store them in @bsz and return zero.
281      * On failure, return negative errno.
282      */
283     int (*bdrv_probe_blocksizes)(BlockDriverState *bs, BlockSizes *bsz);
284     /**
285      * Try to get @bs's geometry (cyls, heads, sectors)
286      * On success, store them in @geo and return 0.
287      * On failure return -errno.
288      * Only drivers that want to override guest geometry implement this
289      * callback; see hd_geometry_guess().
290      */
291     int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo);
292 
293     QLIST_ENTRY(BlockDriver) list;
294 };
295 
296 typedef struct BlockLimits {
297     /* maximum number of sectors that can be discarded at once */
298     int max_discard;
299 
300     /* optimal alignment for discard requests in sectors */
301     int64_t discard_alignment;
302 
303     /* maximum number of sectors that can zeroized at once */
304     int max_write_zeroes;
305 
306     /* optimal alignment for write zeroes requests in sectors */
307     int64_t write_zeroes_alignment;
308 
309     /* optimal transfer length in sectors */
310     int opt_transfer_length;
311 
312     /* maximal transfer length in sectors */
313     int max_transfer_length;
314 
315     /* memory alignment so that no bounce buffer is needed */
316     size_t opt_mem_alignment;
317 } BlockLimits;
318 
319 typedef struct BdrvOpBlocker BdrvOpBlocker;
320 
321 typedef struct BdrvAioNotifier {
322     void (*attached_aio_context)(AioContext *new_context, void *opaque);
323     void (*detach_aio_context)(void *opaque);
324 
325     void *opaque;
326 
327     QLIST_ENTRY(BdrvAioNotifier) list;
328 } BdrvAioNotifier;
329 
330 /*
331  * Note: the function bdrv_append() copies and swaps contents of
332  * BlockDriverStates, so if you add new fields to this struct, please
333  * inspect bdrv_append() to determine if the new fields need to be
334  * copied as well.
335  */
336 struct BlockDriverState {
337     int64_t total_sectors; /* if we are reading a disk image, give its
338                               size in sectors */
339     int read_only; /* if true, the media is read only */
340     int open_flags; /* flags used to open the file, re-used for re-open */
341     int encrypted; /* if true, the media is encrypted */
342     int valid_key; /* if true, a valid encryption key has been set */
343     int sg;        /* if true, the device is a /dev/sg* */
344     int copy_on_read; /* if true, copy read backing sectors into image
345                          note this is a reference count */
346     bool probed;
347 
348     BlockDriver *drv; /* NULL means no media */
349     void *opaque;
350 
351     BlockBackend *blk;          /* owning backend, if any */
352 
353     AioContext *aio_context; /* event loop used for fd handlers, timers, etc */
354     /* long-running tasks intended to always use the same AioContext as this
355      * BDS may register themselves in this list to be notified of changes
356      * regarding this BDS's context */
357     QLIST_HEAD(, BdrvAioNotifier) aio_notifiers;
358 
359     char filename[PATH_MAX];
360     char backing_file[PATH_MAX]; /* if non zero, the image is a diff of
361                                     this file image */
362     char backing_format[16]; /* if non-zero and backing_file exists */
363 
364     QDict *full_open_options;
365     char exact_filename[PATH_MAX];
366 
367     BlockDriverState *backing_hd;
368     BlockDriverState *file;
369 
370     NotifierList close_notifiers;
371 
372     /* Callback before write request is processed */
373     NotifierWithReturnList before_write_notifiers;
374 
375     /* number of in-flight serialising requests */
376     unsigned int serialising_in_flight;
377 
378     /* I/O throttling */
379     ThrottleState throttle_state;
380     CoQueue      throttled_reqs[2];
381     bool         io_limits_enabled;
382 
383     /* I/O stats (display with "info blockstats"). */
384     BlockAcctStats stats;
385 
386     /* I/O Limits */
387     BlockLimits bl;
388 
389     /* Whether produces zeros when read beyond eof */
390     bool zero_beyond_eof;
391 
392     /* Alignment requirement for offset/length of I/O requests */
393     unsigned int request_alignment;
394 
395     /* the block size for which the guest device expects atomicity */
396     int guest_block_size;
397 
398     /* do we need to tell the quest if we have a volatile write cache? */
399     int enable_write_cache;
400 
401     /* NOTE: the following infos are only hints for real hardware
402        drivers. They are not used by the block driver */
403     BlockdevOnError on_read_error, on_write_error;
404     bool iostatus_enabled;
405     BlockDeviceIoStatus iostatus;
406 
407     /* the following member gives a name to every node on the bs graph. */
408     char node_name[32];
409     /* element of the list of named nodes building the graph */
410     QTAILQ_ENTRY(BlockDriverState) node_list;
411     /* element of the list of "drives" the guest sees */
412     QTAILQ_ENTRY(BlockDriverState) device_list;
413     QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
414     int refcnt;
415 
416     QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
417 
418     /* operation blockers */
419     QLIST_HEAD(, BdrvOpBlocker) op_blockers[BLOCK_OP_TYPE_MAX];
420 
421     /* long-running background operation */
422     BlockJob *job;
423 
424     QDict *options;
425     BlockdevDetectZeroesOptions detect_zeroes;
426 
427     /* The error object in use for blocking operations on backing_hd */
428     Error *backing_blocker;
429 
430     /* threshold limit for writes, in bytes. "High water mark". */
431     uint64_t write_threshold_offset;
432     NotifierWithReturn write_threshold_notifier;
433 };
434 
435 
436 /* Essential block drivers which must always be statically linked into qemu, and
437  * which therefore can be accessed without using bdrv_find_format() */
438 extern BlockDriver bdrv_file;
439 extern BlockDriver bdrv_raw;
440 extern BlockDriver bdrv_qcow2;
441 
442 
443 int get_tmp_filename(char *filename, int size);
444 BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
445                             const char *filename);
446 
447 void bdrv_set_io_limits(BlockDriverState *bs,
448                         ThrottleConfig *cfg);
449 
450 
451 /**
452  * bdrv_add_before_write_notifier:
453  *
454  * Register a callback that is invoked before write requests are processed but
455  * after any throttling or waiting for overlapping requests.
456  */
457 void bdrv_add_before_write_notifier(BlockDriverState *bs,
458                                     NotifierWithReturn *notifier);
459 
460 /**
461  * bdrv_detach_aio_context:
462  *
463  * May be called from .bdrv_detach_aio_context() to detach children from the
464  * current #AioContext.  This is only needed by block drivers that manage their
465  * own children.  Both ->file and ->backing_hd are automatically handled and
466  * block drivers should not call this function on them explicitly.
467  */
468 void bdrv_detach_aio_context(BlockDriverState *bs);
469 
470 /**
471  * bdrv_attach_aio_context:
472  *
473  * May be called from .bdrv_attach_aio_context() to attach children to the new
474  * #AioContext.  This is only needed by block drivers that manage their own
475  * children.  Both ->file and ->backing_hd are automatically handled and block
476  * drivers should not call this function on them explicitly.
477  */
478 void bdrv_attach_aio_context(BlockDriverState *bs,
479                              AioContext *new_context);
480 
481 /**
482  * bdrv_add_aio_context_notifier:
483  *
484  * If a long-running job intends to be always run in the same AioContext as a
485  * certain BDS, it may use this function to be notified of changes regarding the
486  * association of the BDS to an AioContext.
487  *
488  * attached_aio_context() is called after the target BDS has been attached to a
489  * new AioContext; detach_aio_context() is called before the target BDS is being
490  * detached from its old AioContext.
491  */
492 void bdrv_add_aio_context_notifier(BlockDriverState *bs,
493         void (*attached_aio_context)(AioContext *new_context, void *opaque),
494         void (*detach_aio_context)(void *opaque), void *opaque);
495 
496 /**
497  * bdrv_remove_aio_context_notifier:
498  *
499  * Unsubscribe of change notifications regarding the BDS's AioContext. The
500  * parameters given here have to be the same as those given to
501  * bdrv_add_aio_context_notifier().
502  */
503 void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
504                                       void (*aio_context_attached)(AioContext *,
505                                                                    void *),
506                                       void (*aio_context_detached)(void *),
507                                       void *opaque);
508 
509 #ifdef _WIN32
510 int is_windows_drive(const char *filename);
511 #endif
512 
513 /**
514  * stream_start:
515  * @bs: Block device to operate on.
516  * @base: Block device that will become the new base, or %NULL to
517  * flatten the whole backing file chain onto @bs.
518  * @base_id: The file name that will be written to @bs as the new
519  * backing file if the job completes.  Ignored if @base is %NULL.
520  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
521  * @on_error: The action to take upon error.
522  * @cb: Completion function for the job.
523  * @opaque: Opaque pointer value passed to @cb.
524  * @errp: Error object.
525  *
526  * Start a streaming operation on @bs.  Clusters that are unallocated
527  * in @bs, but allocated in any image between @base and @bs (both
528  * exclusive) will be written to @bs.  At the end of a successful
529  * streaming job, the backing file of @bs will be changed to
530  * @base_id in the written image and to @base in the live BlockDriverState.
531  */
532 void stream_start(BlockDriverState *bs, BlockDriverState *base,
533                   const char *base_id, int64_t speed, BlockdevOnError on_error,
534                   BlockCompletionFunc *cb,
535                   void *opaque, Error **errp);
536 
537 /**
538  * commit_start:
539  * @bs: Active block device.
540  * @top: Top block device to be committed.
541  * @base: Block device that will be written into, and become the new top.
542  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
543  * @on_error: The action to take upon error.
544  * @cb: Completion function for the job.
545  * @opaque: Opaque pointer value passed to @cb.
546  * @backing_file_str: String to use as the backing file in @top's overlay
547  * @errp: Error object.
548  *
549  */
550 void commit_start(BlockDriverState *bs, BlockDriverState *base,
551                  BlockDriverState *top, int64_t speed,
552                  BlockdevOnError on_error, BlockCompletionFunc *cb,
553                  void *opaque, const char *backing_file_str, Error **errp);
554 /**
555  * commit_active_start:
556  * @bs: Active block device to be committed.
557  * @base: Block device that will be written into, and become the new top.
558  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
559  * @on_error: The action to take upon error.
560  * @cb: Completion function for the job.
561  * @opaque: Opaque pointer value passed to @cb.
562  * @errp: Error object.
563  *
564  */
565 void commit_active_start(BlockDriverState *bs, BlockDriverState *base,
566                          int64_t speed,
567                          BlockdevOnError on_error,
568                          BlockCompletionFunc *cb,
569                          void *opaque, Error **errp);
570 /*
571  * mirror_start:
572  * @bs: Block device to operate on.
573  * @target: Block device to write to.
574  * @replaces: Block graph node name to replace once the mirror is done. Can
575  *            only be used when full mirroring is selected.
576  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
577  * @granularity: The chosen granularity for the dirty bitmap.
578  * @buf_size: The amount of data that can be in flight at one time.
579  * @mode: Whether to collapse all images in the chain to the target.
580  * @on_source_error: The action to take upon error reading from the source.
581  * @on_target_error: The action to take upon error writing to the target.
582  * @cb: Completion function for the job.
583  * @opaque: Opaque pointer value passed to @cb.
584  * @errp: Error object.
585  *
586  * Start a mirroring operation on @bs.  Clusters that are allocated
587  * in @bs will be written to @bs until the job is cancelled or
588  * manually completed.  At the end of a successful mirroring job,
589  * @bs will be switched to read from @target.
590  */
591 void mirror_start(BlockDriverState *bs, BlockDriverState *target,
592                   const char *replaces,
593                   int64_t speed, int64_t granularity, int64_t buf_size,
594                   MirrorSyncMode mode, BlockdevOnError on_source_error,
595                   BlockdevOnError on_target_error,
596                   BlockCompletionFunc *cb,
597                   void *opaque, Error **errp);
598 
599 /*
600  * backup_start:
601  * @bs: Block device to operate on.
602  * @target: Block device to write to.
603  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
604  * @sync_mode: What parts of the disk image should be copied to the destination.
605  * @on_source_error: The action to take upon error reading from the source.
606  * @on_target_error: The action to take upon error writing to the target.
607  * @cb: Completion function for the job.
608  * @opaque: Opaque pointer value passed to @cb.
609  *
610  * Start a backup operation on @bs.  Clusters in @bs are written to @target
611  * until the job is cancelled or manually completed.
612  */
613 void backup_start(BlockDriverState *bs, BlockDriverState *target,
614                   int64_t speed, MirrorSyncMode sync_mode,
615                   BlockdevOnError on_source_error,
616                   BlockdevOnError on_target_error,
617                   BlockCompletionFunc *cb, void *opaque,
618                   Error **errp);
619 
620 void blk_dev_change_media_cb(BlockBackend *blk, bool load);
621 bool blk_dev_has_removable_media(BlockBackend *blk);
622 void blk_dev_eject_request(BlockBackend *blk, bool force);
623 bool blk_dev_is_tray_open(BlockBackend *blk);
624 bool blk_dev_is_medium_locked(BlockBackend *blk);
625 void blk_dev_resize_cb(BlockBackend *blk);
626 
627 #endif /* BLOCK_INT_H */
628