xref: /openbmc/qemu/include/block/block_int.h (revision ac1d8878)
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 enum BdrvTrackedRequestType {
64     BDRV_TRACKED_READ,
65     BDRV_TRACKED_WRITE,
66     BDRV_TRACKED_FLUSH,
67     BDRV_TRACKED_IOCTL,
68     BDRV_TRACKED_DISCARD,
69 };
70 
71 typedef struct BdrvTrackedRequest {
72     BlockDriverState *bs;
73     int64_t offset;
74     unsigned int bytes;
75     enum BdrvTrackedRequestType type;
76 
77     bool serialising;
78     int64_t overlap_offset;
79     unsigned int overlap_bytes;
80 
81     QLIST_ENTRY(BdrvTrackedRequest) list;
82     Coroutine *co; /* owner, used for deadlock detection */
83     CoQueue wait_queue; /* coroutines blocked on this request */
84 
85     struct BdrvTrackedRequest *waiting_for;
86 } BdrvTrackedRequest;
87 
88 struct BlockDriver {
89     const char *format_name;
90     int instance_size;
91 
92     /* set to true if the BlockDriver is a block filter */
93     bool is_filter;
94     /* for snapshots block filter like Quorum can implement the
95      * following recursive callback.
96      * It's purpose is to recurse on the filter children while calling
97      * bdrv_recurse_is_first_non_filter on them.
98      * For a sample implementation look in the future Quorum block filter.
99      */
100     bool (*bdrv_recurse_is_first_non_filter)(BlockDriverState *bs,
101                                              BlockDriverState *candidate);
102 
103     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
104     int (*bdrv_probe_device)(const char *filename);
105 
106     /* Any driver implementing this callback is expected to be able to handle
107      * NULL file names in its .bdrv_open() implementation */
108     void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp);
109     /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have
110      * this field set to true, except ones that are defined only by their
111      * child's bs.
112      * An example of the last type will be the quorum block driver.
113      */
114     bool bdrv_needs_filename;
115 
116     /* Set if a driver can support backing files */
117     bool supports_backing;
118 
119     /* For handling image reopen for split or non-split files */
120     int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,
121                                BlockReopenQueue *queue, Error **errp);
122     void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);
123     void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state);
124 
125     int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags,
126                      Error **errp);
127     int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags,
128                           Error **errp);
129     int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
130                      uint8_t *buf, int nb_sectors);
131     int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
132                       const uint8_t *buf, int nb_sectors);
133     void (*bdrv_close)(BlockDriverState *bs);
134     int (*bdrv_create)(const char *filename, QemuOpts *opts, Error **errp);
135     int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
136     int (*bdrv_make_empty)(BlockDriverState *bs);
137 
138     void (*bdrv_refresh_filename)(BlockDriverState *bs);
139 
140     /* aio */
141     BlockAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
142         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
143         BlockCompletionFunc *cb, void *opaque);
144     BlockAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
145         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
146         BlockCompletionFunc *cb, void *opaque);
147     BlockAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
148         BlockCompletionFunc *cb, void *opaque);
149     BlockAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs,
150         int64_t sector_num, int nb_sectors,
151         BlockCompletionFunc *cb, void *opaque);
152 
153     int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
154         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
155     int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
156         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
157     /*
158      * Efficiently zero a region of the disk image.  Typically an image format
159      * would use a compact metadata representation to implement this.  This
160      * function pointer may be NULL and .bdrv_co_writev() will be called
161      * instead.
162      */
163     int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs,
164         int64_t sector_num, int nb_sectors, BdrvRequestFlags flags);
165     int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
166         int64_t sector_num, int nb_sectors);
167     int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs,
168         int64_t sector_num, int nb_sectors, int *pnum);
169 
170     /*
171      * Invalidate any cached meta-data.
172      */
173     void (*bdrv_invalidate_cache)(BlockDriverState *bs, Error **errp);
174 
175     /*
176      * Flushes all data that was already written to the OS all the way down to
177      * the disk (for example raw-posix calls fsync()).
178      */
179     int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
180 
181     /*
182      * Flushes all internal caches to the OS. The data may still sit in a
183      * writeback cache of the host OS, but it will survive a crash of the qemu
184      * process.
185      */
186     int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
187 
188     const char *protocol_name;
189     int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
190 
191     int64_t (*bdrv_getlength)(BlockDriverState *bs);
192     bool has_variable_length;
193     int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
194 
195     int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
196                                  const uint8_t *buf, int nb_sectors);
197 
198     int (*bdrv_snapshot_create)(BlockDriverState *bs,
199                                 QEMUSnapshotInfo *sn_info);
200     int (*bdrv_snapshot_goto)(BlockDriverState *bs,
201                               const char *snapshot_id);
202     int (*bdrv_snapshot_delete)(BlockDriverState *bs,
203                                 const char *snapshot_id,
204                                 const char *name,
205                                 Error **errp);
206     int (*bdrv_snapshot_list)(BlockDriverState *bs,
207                               QEMUSnapshotInfo **psn_info);
208     int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
209                                   const char *snapshot_id,
210                                   const char *name,
211                                   Error **errp);
212     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
213     ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs);
214 
215     int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov,
216                              int64_t pos);
217     int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
218                              int64_t pos, int size);
219 
220     int (*bdrv_change_backing_file)(BlockDriverState *bs,
221         const char *backing_file, const char *backing_fmt);
222 
223     /* removable device specific */
224     bool (*bdrv_is_inserted)(BlockDriverState *bs);
225     int (*bdrv_media_changed)(BlockDriverState *bs);
226     void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
227     void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
228 
229     /* to control generic scsi devices */
230     BlockAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
231         unsigned long int req, void *buf,
232         BlockCompletionFunc *cb, void *opaque);
233 
234     /* List of options for creating images, terminated by name == NULL */
235     QemuOptsList *create_opts;
236 
237     /*
238      * Returns 0 for completed check, -errno for internal errors.
239      * The check results are stored in result.
240      */
241     int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result,
242         BdrvCheckMode fix);
243 
244     int (*bdrv_amend_options)(BlockDriverState *bs, QemuOpts *opts,
245                               BlockDriverAmendStatusCB *status_cb);
246 
247     void (*bdrv_debug_event)(BlockDriverState *bs, BlkdebugEvent event);
248 
249     /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
250     int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
251         const char *tag);
252     int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs,
253         const char *tag);
254     int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);
255     bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);
256 
257     void (*bdrv_refresh_limits)(BlockDriverState *bs, Error **errp);
258 
259     /*
260      * Returns 1 if newly created images are guaranteed to contain only
261      * zeros, 0 otherwise.
262      */
263     int (*bdrv_has_zero_init)(BlockDriverState *bs);
264 
265     /* Remove fd handlers, timers, and other event loop callbacks so the event
266      * loop is no longer in use.  Called with no in-flight requests and in
267      * depth-first traversal order with parents before child nodes.
268      */
269     void (*bdrv_detach_aio_context)(BlockDriverState *bs);
270 
271     /* Add fd handlers, timers, and other event loop callbacks so I/O requests
272      * can be processed again.  Called with no in-flight requests and in
273      * depth-first traversal order with child nodes before parent nodes.
274      */
275     void (*bdrv_attach_aio_context)(BlockDriverState *bs,
276                                     AioContext *new_context);
277 
278     /* io queue for linux-aio */
279     void (*bdrv_io_plug)(BlockDriverState *bs);
280     void (*bdrv_io_unplug)(BlockDriverState *bs);
281     void (*bdrv_flush_io_queue)(BlockDriverState *bs);
282 
283     /**
284      * Try to get @bs's logical and physical block size.
285      * On success, store them in @bsz and return zero.
286      * On failure, return negative errno.
287      */
288     int (*bdrv_probe_blocksizes)(BlockDriverState *bs, BlockSizes *bsz);
289     /**
290      * Try to get @bs's geometry (cyls, heads, sectors)
291      * On success, store them in @geo and return 0.
292      * On failure return -errno.
293      * Only drivers that want to override guest geometry implement this
294      * callback; see hd_geometry_guess().
295      */
296     int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo);
297 
298     /**
299      * Drain and stop any internal sources of requests in the driver, and
300      * remain so until next I/O callback (e.g. bdrv_co_writev) is called.
301      */
302     void (*bdrv_drain)(BlockDriverState *bs);
303 
304     QLIST_ENTRY(BlockDriver) list;
305 };
306 
307 typedef struct BlockLimits {
308     /* maximum number of sectors that can be discarded at once */
309     int max_discard;
310 
311     /* optimal alignment for discard requests in sectors */
312     int64_t discard_alignment;
313 
314     /* maximum number of sectors that can zeroized at once */
315     int max_write_zeroes;
316 
317     /* optimal alignment for write zeroes requests in sectors */
318     int64_t write_zeroes_alignment;
319 
320     /* optimal transfer length in sectors */
321     int opt_transfer_length;
322 
323     /* maximal transfer length in sectors */
324     int max_transfer_length;
325 
326     /* memory alignment so that no bounce buffer is needed */
327     size_t min_mem_alignment;
328 
329     /* memory alignment for bounce buffer */
330     size_t opt_mem_alignment;
331 } BlockLimits;
332 
333 typedef struct BdrvOpBlocker BdrvOpBlocker;
334 
335 typedef struct BdrvAioNotifier {
336     void (*attached_aio_context)(AioContext *new_context, void *opaque);
337     void (*detach_aio_context)(void *opaque);
338 
339     void *opaque;
340 
341     QLIST_ENTRY(BdrvAioNotifier) list;
342 } BdrvAioNotifier;
343 
344 struct BdrvChildRole {
345     int (*inherit_flags)(int parent_flags);
346 };
347 
348 extern const BdrvChildRole child_file;
349 extern const BdrvChildRole child_format;
350 
351 struct BdrvChild {
352     BlockDriverState *bs;
353     const BdrvChildRole *role;
354     QLIST_ENTRY(BdrvChild) next;
355     QLIST_ENTRY(BdrvChild) next_parent;
356 };
357 
358 /*
359  * Note: the function bdrv_append() copies and swaps contents of
360  * BlockDriverStates, so if you add new fields to this struct, please
361  * inspect bdrv_append() to determine if the new fields need to be
362  * copied as well.
363  */
364 struct BlockDriverState {
365     int64_t total_sectors; /* if we are reading a disk image, give its
366                               size in sectors */
367     int read_only; /* if true, the media is read only */
368     int open_flags; /* flags used to open the file, re-used for re-open */
369     int encrypted; /* if true, the media is encrypted */
370     int valid_key; /* if true, a valid encryption key has been set */
371     int sg;        /* if true, the device is a /dev/sg* */
372     int copy_on_read; /* if true, copy read backing sectors into image
373                          note this is a reference count */
374     bool probed;
375 
376     BlockDriver *drv; /* NULL means no media */
377     void *opaque;
378 
379     BlockBackend *blk;          /* owning backend, if any */
380 
381     AioContext *aio_context; /* event loop used for fd handlers, timers, etc */
382     /* long-running tasks intended to always use the same AioContext as this
383      * BDS may register themselves in this list to be notified of changes
384      * regarding this BDS's context */
385     QLIST_HEAD(, BdrvAioNotifier) aio_notifiers;
386 
387     char filename[PATH_MAX];
388     char backing_file[PATH_MAX]; /* if non zero, the image is a diff of
389                                     this file image */
390     char backing_format[16]; /* if non-zero and backing_file exists */
391 
392     QDict *full_open_options;
393     char exact_filename[PATH_MAX];
394 
395     BdrvChild *backing;
396     BdrvChild *file;
397 
398     NotifierList close_notifiers;
399 
400     /* Callback before write request is processed */
401     NotifierWithReturnList before_write_notifiers;
402 
403     /* number of in-flight serialising requests */
404     unsigned int serialising_in_flight;
405 
406     /* I/O throttling.
407      * throttle_state tells us if this BDS has I/O limits configured.
408      * io_limits_enabled tells us if they are currently being
409      * enforced, but it can be temporarily set to false */
410     CoQueue      throttled_reqs[2];
411     bool         io_limits_enabled;
412     /* The following fields are protected by the ThrottleGroup lock.
413      * See the ThrottleGroup documentation for details. */
414     ThrottleState *throttle_state;
415     ThrottleTimers throttle_timers;
416     unsigned       pending_reqs[2];
417     QLIST_ENTRY(BlockDriverState) round_robin;
418 
419     /* Offset after the highest byte written to */
420     uint64_t wr_highest_offset;
421 
422     /* I/O Limits */
423     BlockLimits bl;
424 
425     /* Whether produces zeros when read beyond eof */
426     bool zero_beyond_eof;
427 
428     /* Alignment requirement for offset/length of I/O requests */
429     unsigned int request_alignment;
430 
431     /* do we need to tell the quest if we have a volatile write cache? */
432     int enable_write_cache;
433 
434     /* the following member gives a name to every node on the bs graph. */
435     char node_name[32];
436     /* element of the list of named nodes building the graph */
437     QTAILQ_ENTRY(BlockDriverState) node_list;
438     /* element of the list of "drives" the guest sees */
439     QTAILQ_ENTRY(BlockDriverState) device_list;
440     QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
441     int refcnt;
442 
443     QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
444 
445     /* operation blockers */
446     QLIST_HEAD(, BdrvOpBlocker) op_blockers[BLOCK_OP_TYPE_MAX];
447 
448     /* long-running background operation */
449     BlockJob *job;
450 
451     /* The node that this node inherited default options from (and a reopen on
452      * which can affect this node by changing these defaults). This is always a
453      * parent node of this node. */
454     BlockDriverState *inherits_from;
455     QLIST_HEAD(, BdrvChild) children;
456     QLIST_HEAD(, BdrvChild) parents;
457 
458     QDict *options;
459     BlockdevDetectZeroesOptions detect_zeroes;
460 
461     /* The error object in use for blocking operations on backing_hd */
462     Error *backing_blocker;
463 
464     /* threshold limit for writes, in bytes. "High water mark". */
465     uint64_t write_threshold_offset;
466     NotifierWithReturn write_threshold_notifier;
467 
468     int quiesce_counter;
469 };
470 
471 struct BlockBackendRootState {
472     int open_flags;
473     bool read_only;
474     BlockdevDetectZeroesOptions detect_zeroes;
475 
476     char *throttle_group;
477     ThrottleState *throttle_state;
478 };
479 
480 static inline BlockDriverState *backing_bs(BlockDriverState *bs)
481 {
482     return bs->backing ? bs->backing->bs : NULL;
483 }
484 
485 
486 /* Essential block drivers which must always be statically linked into qemu, and
487  * which therefore can be accessed without using bdrv_find_format() */
488 extern BlockDriver bdrv_file;
489 extern BlockDriver bdrv_raw;
490 extern BlockDriver bdrv_qcow2;
491 
492 extern QTAILQ_HEAD(BdrvStates, BlockDriverState) bdrv_states;
493 
494 /**
495  * bdrv_setup_io_funcs:
496  *
497  * Prepare a #BlockDriver for I/O request processing by populating
498  * unimplemented coroutine and AIO interfaces with generic wrapper functions
499  * that fall back to implemented interfaces.
500  */
501 void bdrv_setup_io_funcs(BlockDriver *bdrv);
502 
503 int get_tmp_filename(char *filename, int size);
504 BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
505                             const char *filename);
506 
507 void bdrv_set_io_limits(BlockDriverState *bs,
508                         ThrottleConfig *cfg);
509 
510 
511 /**
512  * bdrv_add_before_write_notifier:
513  *
514  * Register a callback that is invoked before write requests are processed but
515  * after any throttling or waiting for overlapping requests.
516  */
517 void bdrv_add_before_write_notifier(BlockDriverState *bs,
518                                     NotifierWithReturn *notifier);
519 
520 /**
521  * bdrv_detach_aio_context:
522  *
523  * May be called from .bdrv_detach_aio_context() to detach children from the
524  * current #AioContext.  This is only needed by block drivers that manage their
525  * own children.  Both ->file and ->backing are automatically handled and
526  * block drivers should not call this function on them explicitly.
527  */
528 void bdrv_detach_aio_context(BlockDriverState *bs);
529 
530 /**
531  * bdrv_attach_aio_context:
532  *
533  * May be called from .bdrv_attach_aio_context() to attach children to the new
534  * #AioContext.  This is only needed by block drivers that manage their own
535  * children.  Both ->file and ->backing are automatically handled and block
536  * drivers should not call this function on them explicitly.
537  */
538 void bdrv_attach_aio_context(BlockDriverState *bs,
539                              AioContext *new_context);
540 
541 /**
542  * bdrv_add_aio_context_notifier:
543  *
544  * If a long-running job intends to be always run in the same AioContext as a
545  * certain BDS, it may use this function to be notified of changes regarding the
546  * association of the BDS to an AioContext.
547  *
548  * attached_aio_context() is called after the target BDS has been attached to a
549  * new AioContext; detach_aio_context() is called before the target BDS is being
550  * detached from its old AioContext.
551  */
552 void bdrv_add_aio_context_notifier(BlockDriverState *bs,
553         void (*attached_aio_context)(AioContext *new_context, void *opaque),
554         void (*detach_aio_context)(void *opaque), void *opaque);
555 
556 /**
557  * bdrv_remove_aio_context_notifier:
558  *
559  * Unsubscribe of change notifications regarding the BDS's AioContext. The
560  * parameters given here have to be the same as those given to
561  * bdrv_add_aio_context_notifier().
562  */
563 void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
564                                       void (*aio_context_attached)(AioContext *,
565                                                                    void *),
566                                       void (*aio_context_detached)(void *),
567                                       void *opaque);
568 
569 #ifdef _WIN32
570 int is_windows_drive(const char *filename);
571 #endif
572 
573 /**
574  * stream_start:
575  * @bs: Block device to operate on.
576  * @base: Block device that will become the new base, or %NULL to
577  * flatten the whole backing file chain onto @bs.
578  * @base_id: The file name that will be written to @bs as the new
579  * backing file if the job completes.  Ignored if @base is %NULL.
580  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
581  * @on_error: The action to take upon error.
582  * @cb: Completion function for the job.
583  * @opaque: Opaque pointer value passed to @cb.
584  * @errp: Error object.
585  *
586  * Start a streaming operation on @bs.  Clusters that are unallocated
587  * in @bs, but allocated in any image between @base and @bs (both
588  * exclusive) will be written to @bs.  At the end of a successful
589  * streaming job, the backing file of @bs will be changed to
590  * @base_id in the written image and to @base in the live BlockDriverState.
591  */
592 void stream_start(BlockDriverState *bs, BlockDriverState *base,
593                   const char *base_id, int64_t speed, BlockdevOnError on_error,
594                   BlockCompletionFunc *cb,
595                   void *opaque, Error **errp);
596 
597 /**
598  * commit_start:
599  * @bs: Active block device.
600  * @top: Top block device to be committed.
601  * @base: Block device that will be written into, and become the new top.
602  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
603  * @on_error: The action to take upon error.
604  * @cb: Completion function for the job.
605  * @opaque: Opaque pointer value passed to @cb.
606  * @backing_file_str: String to use as the backing file in @top's overlay
607  * @errp: Error object.
608  *
609  */
610 void commit_start(BlockDriverState *bs, BlockDriverState *base,
611                  BlockDriverState *top, int64_t speed,
612                  BlockdevOnError on_error, BlockCompletionFunc *cb,
613                  void *opaque, const char *backing_file_str, Error **errp);
614 /**
615  * commit_active_start:
616  * @bs: Active block device to be committed.
617  * @base: Block device that will be written into, and become the new top.
618  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
619  * @on_error: The action to take upon error.
620  * @cb: Completion function for the job.
621  * @opaque: Opaque pointer value passed to @cb.
622  * @errp: Error object.
623  *
624  */
625 void commit_active_start(BlockDriverState *bs, BlockDriverState *base,
626                          int64_t speed,
627                          BlockdevOnError on_error,
628                          BlockCompletionFunc *cb,
629                          void *opaque, Error **errp);
630 /*
631  * mirror_start:
632  * @bs: Block device to operate on.
633  * @target: Block device to write to.
634  * @replaces: Block graph node name to replace once the mirror is done. Can
635  *            only be used when full mirroring is selected.
636  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
637  * @granularity: The chosen granularity for the dirty bitmap.
638  * @buf_size: The amount of data that can be in flight at one time.
639  * @mode: Whether to collapse all images in the chain to the target.
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  * @unmap: Whether to unmap target where source sectors only contain zeroes.
643  * @cb: Completion function for the job.
644  * @opaque: Opaque pointer value passed to @cb.
645  * @errp: Error object.
646  *
647  * Start a mirroring operation on @bs.  Clusters that are allocated
648  * in @bs will be written to @bs until the job is cancelled or
649  * manually completed.  At the end of a successful mirroring job,
650  * @bs will be switched to read from @target.
651  */
652 void mirror_start(BlockDriverState *bs, BlockDriverState *target,
653                   const char *replaces,
654                   int64_t speed, uint32_t granularity, int64_t buf_size,
655                   MirrorSyncMode mode, BlockdevOnError on_source_error,
656                   BlockdevOnError on_target_error,
657                   bool unmap,
658                   BlockCompletionFunc *cb,
659                   void *opaque, Error **errp);
660 
661 /*
662  * backup_start:
663  * @bs: Block device to operate on.
664  * @target: Block device to write to.
665  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
666  * @sync_mode: What parts of the disk image should be copied to the destination.
667  * @sync_bitmap: The dirty bitmap if sync_mode is MIRROR_SYNC_MODE_INCREMENTAL.
668  * @on_source_error: The action to take upon error reading from the source.
669  * @on_target_error: The action to take upon error writing to the target.
670  * @cb: Completion function for the job.
671  * @opaque: Opaque pointer value passed to @cb.
672  * @txn: Transaction that this job is part of (may be NULL).
673  *
674  * Start a backup operation on @bs.  Clusters in @bs are written to @target
675  * until the job is cancelled or manually completed.
676  */
677 void backup_start(BlockDriverState *bs, BlockDriverState *target,
678                   int64_t speed, MirrorSyncMode sync_mode,
679                   BdrvDirtyBitmap *sync_bitmap,
680                   BlockdevOnError on_source_error,
681                   BlockdevOnError on_target_error,
682                   BlockCompletionFunc *cb, void *opaque,
683                   BlockJobTxn *txn, Error **errp);
684 
685 void blk_set_bs(BlockBackend *blk, BlockDriverState *bs);
686 
687 void blk_dev_change_media_cb(BlockBackend *blk, bool load);
688 bool blk_dev_has_removable_media(BlockBackend *blk);
689 void blk_dev_eject_request(BlockBackend *blk, bool force);
690 bool blk_dev_is_tray_open(BlockBackend *blk);
691 bool blk_dev_is_medium_locked(BlockBackend *blk);
692 void blk_dev_resize_cb(BlockBackend *blk);
693 
694 void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, int nr_sectors);
695 bool bdrv_requests_pending(BlockDriverState *bs);
696 
697 void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out);
698 void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in);
699 
700 #endif /* BLOCK_INT_H */
701