xref: /openbmc/qemu/include/block/block_int.h (revision f8ed85ac)
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 "qemu/hbitmap.h"
35 #include "block/snapshot.h"
36 #include "qemu/main-loop.h"
37 #include "qemu/throttle.h"
38 
39 #define BLOCK_FLAG_ENCRYPT          1
40 #define BLOCK_FLAG_COMPAT6          4
41 #define BLOCK_FLAG_LAZY_REFCOUNTS   8
42 
43 #define BLOCK_OPT_SIZE              "size"
44 #define BLOCK_OPT_ENCRYPT           "encryption"
45 #define BLOCK_OPT_COMPAT6           "compat6"
46 #define BLOCK_OPT_BACKING_FILE      "backing_file"
47 #define BLOCK_OPT_BACKING_FMT       "backing_fmt"
48 #define BLOCK_OPT_CLUSTER_SIZE      "cluster_size"
49 #define BLOCK_OPT_TABLE_SIZE        "table_size"
50 #define BLOCK_OPT_PREALLOC          "preallocation"
51 #define BLOCK_OPT_SUBFMT            "subformat"
52 #define BLOCK_OPT_COMPAT_LEVEL      "compat"
53 #define BLOCK_OPT_LAZY_REFCOUNTS    "lazy_refcounts"
54 #define BLOCK_OPT_ADAPTER_TYPE      "adapter_type"
55 #define BLOCK_OPT_REDUNDANCY        "redundancy"
56 #define BLOCK_OPT_NOCOW             "nocow"
57 #define BLOCK_OPT_OBJECT_SIZE       "object_size"
58 #define BLOCK_OPT_REFCOUNT_BITS     "refcount_bits"
59 
60 #define BLOCK_PROBE_BUF_SIZE        512
61 
62 typedef struct BdrvTrackedRequest {
63     BlockDriverState *bs;
64     int64_t offset;
65     unsigned int bytes;
66     bool is_write;
67 
68     bool serialising;
69     int64_t overlap_offset;
70     unsigned int overlap_bytes;
71 
72     QLIST_ENTRY(BdrvTrackedRequest) list;
73     Coroutine *co; /* owner, used for deadlock detection */
74     CoQueue wait_queue; /* coroutines blocked on this request */
75 
76     struct BdrvTrackedRequest *waiting_for;
77 } BdrvTrackedRequest;
78 
79 struct BlockDriver {
80     const char *format_name;
81     int instance_size;
82 
83     /* set to true if the BlockDriver is a block filter */
84     bool is_filter;
85     /* for snapshots block filter like Quorum can implement the
86      * following recursive callback.
87      * It's purpose is to recurse on the filter children while calling
88      * bdrv_recurse_is_first_non_filter on them.
89      * For a sample implementation look in the future Quorum block filter.
90      */
91     bool (*bdrv_recurse_is_first_non_filter)(BlockDriverState *bs,
92                                              BlockDriverState *candidate);
93 
94     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
95     int (*bdrv_probe_device)(const char *filename);
96 
97     /* Any driver implementing this callback is expected to be able to handle
98      * NULL file names in its .bdrv_open() implementation */
99     void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp);
100     /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have
101      * this field set to true, except ones that are defined only by their
102      * child's bs.
103      * An example of the last type will be the quorum block driver.
104      */
105     bool bdrv_needs_filename;
106 
107     /* Set if a driver can support backing files */
108     bool supports_backing;
109 
110     /* For handling image reopen for split or non-split files */
111     int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,
112                                BlockReopenQueue *queue, Error **errp);
113     void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);
114     void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state);
115 
116     int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags,
117                      Error **errp);
118     int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags,
119                           Error **errp);
120     int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
121                      uint8_t *buf, int nb_sectors);
122     int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
123                       const uint8_t *buf, int nb_sectors);
124     void (*bdrv_close)(BlockDriverState *bs);
125     void (*bdrv_rebind)(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     int (*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 };
343 
344 /*
345  * Note: the function bdrv_append() copies and swaps contents of
346  * BlockDriverStates, so if you add new fields to this struct, please
347  * inspect bdrv_append() to determine if the new fields need to be
348  * copied as well.
349  */
350 struct BlockDriverState {
351     int64_t total_sectors; /* if we are reading a disk image, give its
352                               size in sectors */
353     int read_only; /* if true, the media is read only */
354     int open_flags; /* flags used to open the file, re-used for re-open */
355     int encrypted; /* if true, the media is encrypted */
356     int valid_key; /* if true, a valid encryption key has been set */
357     int sg;        /* if true, the device is a /dev/sg* */
358     int copy_on_read; /* if true, copy read backing sectors into image
359                          note this is a reference count */
360     bool probed;
361 
362     BlockDriver *drv; /* NULL means no media */
363     void *opaque;
364 
365     BlockBackend *blk;          /* owning backend, if any */
366 
367     AioContext *aio_context; /* event loop used for fd handlers, timers, etc */
368     /* long-running tasks intended to always use the same AioContext as this
369      * BDS may register themselves in this list to be notified of changes
370      * regarding this BDS's context */
371     QLIST_HEAD(, BdrvAioNotifier) aio_notifiers;
372 
373     char filename[PATH_MAX];
374     char backing_file[PATH_MAX]; /* if non zero, the image is a diff of
375                                     this file image */
376     char backing_format[16]; /* if non-zero and backing_file exists */
377 
378     QDict *full_open_options;
379     char exact_filename[PATH_MAX];
380 
381     BlockDriverState *backing_hd;
382     BdrvChild *backing_child;
383     BlockDriverState *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     /* I/O stats (display with "info blockstats"). */
404     BlockAcctStats stats;
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     /* the block size for which the guest device expects atomicity */
416     int guest_block_size;
417 
418     /* do we need to tell the quest if we have a volatile write cache? */
419     int enable_write_cache;
420 
421     /* NOTE: the following infos are only hints for real hardware
422        drivers. They are not used by the block driver */
423     BlockdevOnError on_read_error, on_write_error;
424     bool iostatus_enabled;
425     BlockDeviceIoStatus iostatus;
426 
427     /* the following member gives a name to every node on the bs graph. */
428     char node_name[32];
429     /* element of the list of named nodes building the graph */
430     QTAILQ_ENTRY(BlockDriverState) node_list;
431     /* element of the list of "drives" the guest sees */
432     QTAILQ_ENTRY(BlockDriverState) device_list;
433     QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
434     int refcnt;
435 
436     QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
437 
438     /* operation blockers */
439     QLIST_HEAD(, BdrvOpBlocker) op_blockers[BLOCK_OP_TYPE_MAX];
440 
441     /* long-running background operation */
442     BlockJob *job;
443 
444     /* The node that this node inherited default options from (and a reopen on
445      * which can affect this node by changing these defaults). This is always a
446      * parent node of this node. */
447     BlockDriverState *inherits_from;
448     QLIST_HEAD(, BdrvChild) children;
449 
450     QDict *options;
451     BlockdevDetectZeroesOptions detect_zeroes;
452 
453     /* The error object in use for blocking operations on backing_hd */
454     Error *backing_blocker;
455 
456     /* threshold limit for writes, in bytes. "High water mark". */
457     uint64_t write_threshold_offset;
458     NotifierWithReturn write_threshold_notifier;
459 };
460 
461 
462 /* Essential block drivers which must always be statically linked into qemu, and
463  * which therefore can be accessed without using bdrv_find_format() */
464 extern BlockDriver bdrv_file;
465 extern BlockDriver bdrv_raw;
466 extern BlockDriver bdrv_qcow2;
467 
468 /**
469  * bdrv_setup_io_funcs:
470  *
471  * Prepare a #BlockDriver for I/O request processing by populating
472  * unimplemented coroutine and AIO interfaces with generic wrapper functions
473  * that fall back to implemented interfaces.
474  */
475 void bdrv_setup_io_funcs(BlockDriver *bdrv);
476 
477 int get_tmp_filename(char *filename, int size);
478 BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
479                             const char *filename);
480 
481 void bdrv_set_io_limits(BlockDriverState *bs,
482                         ThrottleConfig *cfg);
483 
484 
485 /**
486  * bdrv_add_before_write_notifier:
487  *
488  * Register a callback that is invoked before write requests are processed but
489  * after any throttling or waiting for overlapping requests.
490  */
491 void bdrv_add_before_write_notifier(BlockDriverState *bs,
492                                     NotifierWithReturn *notifier);
493 
494 /**
495  * bdrv_detach_aio_context:
496  *
497  * May be called from .bdrv_detach_aio_context() to detach children from the
498  * current #AioContext.  This is only needed by block drivers that manage their
499  * own children.  Both ->file and ->backing_hd are automatically handled and
500  * block drivers should not call this function on them explicitly.
501  */
502 void bdrv_detach_aio_context(BlockDriverState *bs);
503 
504 /**
505  * bdrv_attach_aio_context:
506  *
507  * May be called from .bdrv_attach_aio_context() to attach children to the new
508  * #AioContext.  This is only needed by block drivers that manage their own
509  * children.  Both ->file and ->backing_hd are automatically handled and block
510  * drivers should not call this function on them explicitly.
511  */
512 void bdrv_attach_aio_context(BlockDriverState *bs,
513                              AioContext *new_context);
514 
515 /**
516  * bdrv_add_aio_context_notifier:
517  *
518  * If a long-running job intends to be always run in the same AioContext as a
519  * certain BDS, it may use this function to be notified of changes regarding the
520  * association of the BDS to an AioContext.
521  *
522  * attached_aio_context() is called after the target BDS has been attached to a
523  * new AioContext; detach_aio_context() is called before the target BDS is being
524  * detached from its old AioContext.
525  */
526 void bdrv_add_aio_context_notifier(BlockDriverState *bs,
527         void (*attached_aio_context)(AioContext *new_context, void *opaque),
528         void (*detach_aio_context)(void *opaque), void *opaque);
529 
530 /**
531  * bdrv_remove_aio_context_notifier:
532  *
533  * Unsubscribe of change notifications regarding the BDS's AioContext. The
534  * parameters given here have to be the same as those given to
535  * bdrv_add_aio_context_notifier().
536  */
537 void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
538                                       void (*aio_context_attached)(AioContext *,
539                                                                    void *),
540                                       void (*aio_context_detached)(void *),
541                                       void *opaque);
542 
543 #ifdef _WIN32
544 int is_windows_drive(const char *filename);
545 #endif
546 
547 /**
548  * stream_start:
549  * @bs: Block device to operate on.
550  * @base: Block device that will become the new base, or %NULL to
551  * flatten the whole backing file chain onto @bs.
552  * @base_id: The file name that will be written to @bs as the new
553  * backing file if the job completes.  Ignored if @base is %NULL.
554  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
555  * @on_error: The action to take upon error.
556  * @cb: Completion function for the job.
557  * @opaque: Opaque pointer value passed to @cb.
558  * @errp: Error object.
559  *
560  * Start a streaming operation on @bs.  Clusters that are unallocated
561  * in @bs, but allocated in any image between @base and @bs (both
562  * exclusive) will be written to @bs.  At the end of a successful
563  * streaming job, the backing file of @bs will be changed to
564  * @base_id in the written image and to @base in the live BlockDriverState.
565  */
566 void stream_start(BlockDriverState *bs, BlockDriverState *base,
567                   const char *base_id, int64_t speed, BlockdevOnError on_error,
568                   BlockCompletionFunc *cb,
569                   void *opaque, Error **errp);
570 
571 /**
572  * commit_start:
573  * @bs: Active block device.
574  * @top: Top block device to be committed.
575  * @base: Block device that will be written into, and become the new top.
576  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
577  * @on_error: The action to take upon error.
578  * @cb: Completion function for the job.
579  * @opaque: Opaque pointer value passed to @cb.
580  * @backing_file_str: String to use as the backing file in @top's overlay
581  * @errp: Error object.
582  *
583  */
584 void commit_start(BlockDriverState *bs, BlockDriverState *base,
585                  BlockDriverState *top, int64_t speed,
586                  BlockdevOnError on_error, BlockCompletionFunc *cb,
587                  void *opaque, const char *backing_file_str, Error **errp);
588 /**
589  * commit_active_start:
590  * @bs: Active block device to be committed.
591  * @base: Block device that will be written into, and become the new top.
592  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
593  * @on_error: The action to take upon error.
594  * @cb: Completion function for the job.
595  * @opaque: Opaque pointer value passed to @cb.
596  * @errp: Error object.
597  *
598  */
599 void commit_active_start(BlockDriverState *bs, BlockDriverState *base,
600                          int64_t speed,
601                          BlockdevOnError on_error,
602                          BlockCompletionFunc *cb,
603                          void *opaque, Error **errp);
604 /*
605  * mirror_start:
606  * @bs: Block device to operate on.
607  * @target: Block device to write to.
608  * @replaces: Block graph node name to replace once the mirror is done. Can
609  *            only be used when full mirroring is selected.
610  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
611  * @granularity: The chosen granularity for the dirty bitmap.
612  * @buf_size: The amount of data that can be in flight at one time.
613  * @mode: Whether to collapse all images in the chain to the target.
614  * @on_source_error: The action to take upon error reading from the source.
615  * @on_target_error: The action to take upon error writing to the target.
616  * @unmap: Whether to unmap target where source sectors only contain zeroes.
617  * @cb: Completion function for the job.
618  * @opaque: Opaque pointer value passed to @cb.
619  * @errp: Error object.
620  *
621  * Start a mirroring operation on @bs.  Clusters that are allocated
622  * in @bs will be written to @bs until the job is cancelled or
623  * manually completed.  At the end of a successful mirroring job,
624  * @bs will be switched to read from @target.
625  */
626 void mirror_start(BlockDriverState *bs, BlockDriverState *target,
627                   const char *replaces,
628                   int64_t speed, uint32_t granularity, int64_t buf_size,
629                   MirrorSyncMode mode, BlockdevOnError on_source_error,
630                   BlockdevOnError on_target_error,
631                   bool unmap,
632                   BlockCompletionFunc *cb,
633                   void *opaque, Error **errp);
634 
635 /*
636  * backup_start:
637  * @bs: Block device to operate on.
638  * @target: Block device to write to.
639  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
640  * @sync_mode: What parts of the disk image should be copied to the destination.
641  * @sync_bitmap: The dirty bitmap if sync_mode is MIRROR_SYNC_MODE_INCREMENTAL.
642  * @on_source_error: The action to take upon error reading from the source.
643  * @on_target_error: The action to take upon error writing to the target.
644  * @cb: Completion function for the job.
645  * @opaque: Opaque pointer value passed to @cb.
646  *
647  * Start a backup operation on @bs.  Clusters in @bs are written to @target
648  * until the job is cancelled or manually completed.
649  */
650 void backup_start(BlockDriverState *bs, BlockDriverState *target,
651                   int64_t speed, MirrorSyncMode sync_mode,
652                   BdrvDirtyBitmap *sync_bitmap,
653                   BlockdevOnError on_source_error,
654                   BlockdevOnError on_target_error,
655                   BlockCompletionFunc *cb, void *opaque,
656                   Error **errp);
657 
658 void blk_dev_change_media_cb(BlockBackend *blk, bool load);
659 bool blk_dev_has_removable_media(BlockBackend *blk);
660 void blk_dev_eject_request(BlockBackend *blk, bool force);
661 bool blk_dev_is_tray_open(BlockBackend *blk);
662 bool blk_dev_is_medium_locked(BlockBackend *blk);
663 void blk_dev_resize_cb(BlockBackend *blk);
664 
665 void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, int nr_sectors);
666 
667 #endif /* BLOCK_INT_H */
668