xref: /openbmc/qemu/include/block/block_int.h (revision cc7a8ea7)
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 "monitor/monitor.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     void (*bdrv_rebind)(BlockDriverState *bs);
127     int (*bdrv_create)(const char *filename, QemuOpts *opts, Error **errp);
128     int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
129     int (*bdrv_make_empty)(BlockDriverState *bs);
130 
131     void (*bdrv_refresh_filename)(BlockDriverState *bs);
132 
133     /* aio */
134     BlockAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
135         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
136         BlockCompletionFunc *cb, void *opaque);
137     BlockAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
138         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
139         BlockCompletionFunc *cb, void *opaque);
140     BlockAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
141         BlockCompletionFunc *cb, void *opaque);
142     BlockAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs,
143         int64_t sector_num, int nb_sectors,
144         BlockCompletionFunc *cb, void *opaque);
145 
146     int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
147         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
148     int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
149         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
150     /*
151      * Efficiently zero a region of the disk image.  Typically an image format
152      * would use a compact metadata representation to implement this.  This
153      * function pointer may be NULL and .bdrv_co_writev() will be called
154      * instead.
155      */
156     int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs,
157         int64_t sector_num, int nb_sectors, BdrvRequestFlags flags);
158     int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
159         int64_t sector_num, int nb_sectors);
160     int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs,
161         int64_t sector_num, int nb_sectors, int *pnum);
162 
163     /*
164      * Invalidate any cached meta-data.
165      */
166     void (*bdrv_invalidate_cache)(BlockDriverState *bs, Error **errp);
167 
168     /*
169      * Flushes all data that was already written to the OS all the way down to
170      * the disk (for example raw-posix calls fsync()).
171      */
172     int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
173 
174     /*
175      * Flushes all internal caches to the OS. The data may still sit in a
176      * writeback cache of the host OS, but it will survive a crash of the qemu
177      * process.
178      */
179     int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
180 
181     const char *protocol_name;
182     int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
183 
184     int64_t (*bdrv_getlength)(BlockDriverState *bs);
185     bool has_variable_length;
186     int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
187 
188     int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
189                                  const uint8_t *buf, int nb_sectors);
190 
191     int (*bdrv_snapshot_create)(BlockDriverState *bs,
192                                 QEMUSnapshotInfo *sn_info);
193     int (*bdrv_snapshot_goto)(BlockDriverState *bs,
194                               const char *snapshot_id);
195     int (*bdrv_snapshot_delete)(BlockDriverState *bs,
196                                 const char *snapshot_id,
197                                 const char *name,
198                                 Error **errp);
199     int (*bdrv_snapshot_list)(BlockDriverState *bs,
200                               QEMUSnapshotInfo **psn_info);
201     int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
202                                   const char *snapshot_id,
203                                   const char *name,
204                                   Error **errp);
205     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
206     ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs);
207 
208     int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov,
209                              int64_t pos);
210     int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
211                              int64_t pos, int size);
212 
213     int (*bdrv_change_backing_file)(BlockDriverState *bs,
214         const char *backing_file, const char *backing_fmt);
215 
216     /* removable device specific */
217     int (*bdrv_is_inserted)(BlockDriverState *bs);
218     int (*bdrv_media_changed)(BlockDriverState *bs);
219     void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
220     void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
221 
222     /* to control generic scsi devices */
223     int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf);
224     BlockAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
225         unsigned long int req, void *buf,
226         BlockCompletionFunc *cb, void *opaque);
227 
228     /* List of options for creating images, terminated by name == NULL */
229     QemuOptsList *create_opts;
230 
231     /*
232      * Returns 0 for completed check, -errno for internal errors.
233      * The check results are stored in result.
234      */
235     int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result,
236         BdrvCheckMode fix);
237 
238     int (*bdrv_amend_options)(BlockDriverState *bs, QemuOpts *opts,
239                               BlockDriverAmendStatusCB *status_cb);
240 
241     void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event);
242 
243     /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
244     int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
245         const char *tag);
246     int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs,
247         const char *tag);
248     int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);
249     bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);
250 
251     void (*bdrv_refresh_limits)(BlockDriverState *bs, Error **errp);
252 
253     /*
254      * Returns 1 if newly created images are guaranteed to contain only
255      * zeros, 0 otherwise.
256      */
257     int (*bdrv_has_zero_init)(BlockDriverState *bs);
258 
259     /* Remove fd handlers, timers, and other event loop callbacks so the event
260      * loop is no longer in use.  Called with no in-flight requests and in
261      * depth-first traversal order with parents before child nodes.
262      */
263     void (*bdrv_detach_aio_context)(BlockDriverState *bs);
264 
265     /* Add fd handlers, timers, and other event loop callbacks so I/O requests
266      * can be processed again.  Called with no in-flight requests and in
267      * depth-first traversal order with child nodes before parent nodes.
268      */
269     void (*bdrv_attach_aio_context)(BlockDriverState *bs,
270                                     AioContext *new_context);
271 
272     /* io queue for linux-aio */
273     void (*bdrv_io_plug)(BlockDriverState *bs);
274     void (*bdrv_io_unplug)(BlockDriverState *bs);
275     void (*bdrv_flush_io_queue)(BlockDriverState *bs);
276 
277     /**
278      * Try to get @bs's logical and physical block size.
279      * On success, store them in @bsz and return zero.
280      * On failure, return negative errno.
281      */
282     int (*bdrv_probe_blocksizes)(BlockDriverState *bs, BlockSizes *bsz);
283     /**
284      * Try to get @bs's geometry (cyls, heads, sectors)
285      * On success, store them in @geo and return 0.
286      * On failure return -errno.
287      * Only drivers that want to override guest geometry implement this
288      * callback; see hd_geometry_guess().
289      */
290     int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo);
291 
292     QLIST_ENTRY(BlockDriver) list;
293 };
294 
295 typedef struct BlockLimits {
296     /* maximum number of sectors that can be discarded at once */
297     int max_discard;
298 
299     /* optimal alignment for discard requests in sectors */
300     int64_t discard_alignment;
301 
302     /* maximum number of sectors that can zeroized at once */
303     int max_write_zeroes;
304 
305     /* optimal alignment for write zeroes requests in sectors */
306     int64_t write_zeroes_alignment;
307 
308     /* optimal transfer length in sectors */
309     int opt_transfer_length;
310 
311     /* maximal transfer length in sectors */
312     int max_transfer_length;
313 
314     /* memory alignment so that no bounce buffer is needed */
315     size_t min_mem_alignment;
316 
317     /* memory alignment for bounce buffer */
318     size_t opt_mem_alignment;
319 } BlockLimits;
320 
321 typedef struct BdrvOpBlocker BdrvOpBlocker;
322 
323 typedef struct BdrvAioNotifier {
324     void (*attached_aio_context)(AioContext *new_context, void *opaque);
325     void (*detach_aio_context)(void *opaque);
326 
327     void *opaque;
328 
329     QLIST_ENTRY(BdrvAioNotifier) list;
330 } BdrvAioNotifier;
331 
332 struct BdrvChildRole {
333     int (*inherit_flags)(int parent_flags);
334 };
335 
336 extern const BdrvChildRole child_file;
337 extern const BdrvChildRole child_format;
338 
339 typedef struct BdrvChild {
340     BlockDriverState *bs;
341     const BdrvChildRole *role;
342     QLIST_ENTRY(BdrvChild) next;
343 } BdrvChild;
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     BlockDriverState *backing_hd;
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  * @cb: Completion function for the job.
617  * @opaque: Opaque pointer value passed to @cb.
618  * @errp: Error object.
619  *
620  * Start a mirroring operation on @bs.  Clusters that are allocated
621  * in @bs will be written to @bs until the job is cancelled or
622  * manually completed.  At the end of a successful mirroring job,
623  * @bs will be switched to read from @target.
624  */
625 void mirror_start(BlockDriverState *bs, BlockDriverState *target,
626                   const char *replaces,
627                   int64_t speed, uint32_t granularity, int64_t buf_size,
628                   MirrorSyncMode mode, BlockdevOnError on_source_error,
629                   BlockdevOnError on_target_error,
630                   BlockCompletionFunc *cb,
631                   void *opaque, Error **errp);
632 
633 /*
634  * backup_start:
635  * @bs: Block device to operate on.
636  * @target: Block device to write to.
637  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
638  * @sync_mode: What parts of the disk image should be copied to the destination.
639  * @sync_bitmap: The dirty bitmap if sync_mode is MIRROR_SYNC_MODE_DIRTY_BITMAP.
640  * @on_source_error: The action to take upon error reading from the source.
641  * @on_target_error: The action to take upon error writing to the target.
642  * @cb: Completion function for the job.
643  * @opaque: Opaque pointer value passed to @cb.
644  *
645  * Start a backup operation on @bs.  Clusters in @bs are written to @target
646  * until the job is cancelled or manually completed.
647  */
648 void backup_start(BlockDriverState *bs, BlockDriverState *target,
649                   int64_t speed, MirrorSyncMode sync_mode,
650                   BdrvDirtyBitmap *sync_bitmap,
651                   BlockdevOnError on_source_error,
652                   BlockdevOnError on_target_error,
653                   BlockCompletionFunc *cb, void *opaque,
654                   Error **errp);
655 
656 void blk_dev_change_media_cb(BlockBackend *blk, bool load);
657 bool blk_dev_has_removable_media(BlockBackend *blk);
658 void blk_dev_eject_request(BlockBackend *blk, bool force);
659 bool blk_dev_is_tray_open(BlockBackend *blk);
660 bool blk_dev_is_medium_locked(BlockBackend *blk);
661 void blk_dev_resize_cb(BlockBackend *blk);
662 
663 void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, int nr_sectors);
664 void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
665                       int nr_sectors);
666 
667 #endif /* BLOCK_INT_H */
668