xref: /openbmc/qemu/include/block/block_int.h (revision 99d46107)
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/aio-wait.h"
30 #include "qemu/queue.h"
31 #include "qemu/coroutine.h"
32 #include "qemu/stats64.h"
33 #include "qemu/timer.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_LAZY_REFCOUNTS   8
40 
41 #define BLOCK_OPT_SIZE              "size"
42 #define BLOCK_OPT_ENCRYPT           "encryption"
43 #define BLOCK_OPT_ENCRYPT_FORMAT    "encrypt.format"
44 #define BLOCK_OPT_COMPAT6           "compat6"
45 #define BLOCK_OPT_HWVERSION         "hwversion"
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 enum BdrvTrackedRequestType {
63     BDRV_TRACKED_READ,
64     BDRV_TRACKED_WRITE,
65     BDRV_TRACKED_DISCARD,
66     BDRV_TRACKED_TRUNCATE,
67 };
68 
69 typedef struct BdrvTrackedRequest {
70     BlockDriverState *bs;
71     int64_t offset;
72     uint64_t bytes;
73     enum BdrvTrackedRequestType type;
74 
75     bool serialising;
76     int64_t overlap_offset;
77     uint64_t overlap_bytes;
78 
79     QLIST_ENTRY(BdrvTrackedRequest) list;
80     Coroutine *co; /* owner, used for deadlock detection */
81     CoQueue wait_queue; /* coroutines blocked on this request */
82 
83     struct BdrvTrackedRequest *waiting_for;
84 } BdrvTrackedRequest;
85 
86 struct BlockDriver {
87     const char *format_name;
88     int instance_size;
89 
90     /* set to true if the BlockDriver is a block filter. Block filters pass
91      * certain callbacks that refer to data (see block.c) to their bs->file if
92      * the driver doesn't implement them. Drivers that do not wish to forward
93      * must implement them and return -ENOTSUP.
94      */
95     bool is_filter;
96     /* for snapshots block filter like Quorum can implement the
97      * following recursive callback.
98      * It's purpose is to recurse on the filter children while calling
99      * bdrv_recurse_is_first_non_filter on them.
100      * For a sample implementation look in the future Quorum block filter.
101      */
102     bool (*bdrv_recurse_is_first_non_filter)(BlockDriverState *bs,
103                                              BlockDriverState *candidate);
104 
105     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
106     int (*bdrv_probe_device)(const char *filename);
107 
108     /* Any driver implementing this callback is expected to be able to handle
109      * NULL file names in its .bdrv_open() implementation */
110     void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp);
111     /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have
112      * this field set to true, except ones that are defined only by their
113      * child's bs.
114      * An example of the last type will be the quorum block driver.
115      */
116     bool bdrv_needs_filename;
117 
118     /* Set if a driver can support backing files */
119     bool supports_backing;
120 
121     /* For handling image reopen for split or non-split files */
122     int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,
123                                BlockReopenQueue *queue, Error **errp);
124     void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);
125     void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state);
126     void (*bdrv_join_options)(QDict *options, QDict *old_options);
127 
128     int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags,
129                      Error **errp);
130 
131     /* Protocol drivers should implement this instead of bdrv_open */
132     int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags,
133                           Error **errp);
134     void (*bdrv_close)(BlockDriverState *bs);
135     int coroutine_fn (*bdrv_co_create)(BlockdevCreateOptions *opts,
136                                        Error **errp);
137     int coroutine_fn (*bdrv_co_create_opts)(const char *filename,
138                                             QemuOpts *opts,
139                                             Error **errp);
140     int (*bdrv_make_empty)(BlockDriverState *bs);
141 
142     /*
143      * Refreshes the bs->exact_filename field. If that is impossible,
144      * bs->exact_filename has to be left empty.
145      */
146     void (*bdrv_refresh_filename)(BlockDriverState *bs);
147 
148     /*
149      * Gathers the open options for all children into @target.
150      * A simple format driver (without backing file support) might
151      * implement this function like this:
152      *
153      *     QINCREF(bs->file->bs->full_open_options);
154      *     qdict_put(target, "file", bs->file->bs->full_open_options);
155      *
156      * If not specified, the generic implementation will simply put
157      * all children's options under their respective name.
158      *
159      * @backing_overridden is true when bs->backing seems not to be
160      * the child that would result from opening bs->backing_file.
161      * Therefore, if it is true, the backing child's options should be
162      * gathered; otherwise, there is no need since the backing child
163      * is the one implied by the image header.
164      *
165      * Note that ideally this function would not be needed.  Every
166      * block driver which implements it is probably doing something
167      * shady regarding its runtime option structure.
168      */
169     void (*bdrv_gather_child_options)(BlockDriverState *bs, QDict *target,
170                                       bool backing_overridden);
171 
172     /*
173      * Returns an allocated string which is the directory name of this BDS: It
174      * will be used to make relative filenames absolute by prepending this
175      * function's return value to them.
176      */
177     char *(*bdrv_dirname)(BlockDriverState *bs, Error **errp);
178 
179     /* aio */
180     BlockAIOCB *(*bdrv_aio_preadv)(BlockDriverState *bs,
181         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags,
182         BlockCompletionFunc *cb, void *opaque);
183     BlockAIOCB *(*bdrv_aio_pwritev)(BlockDriverState *bs,
184         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags,
185         BlockCompletionFunc *cb, void *opaque);
186     BlockAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
187         BlockCompletionFunc *cb, void *opaque);
188     BlockAIOCB *(*bdrv_aio_pdiscard)(BlockDriverState *bs,
189         int64_t offset, int bytes,
190         BlockCompletionFunc *cb, void *opaque);
191 
192     int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
193         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
194 
195     /**
196      * @offset: position in bytes to read at
197      * @bytes: number of bytes to read
198      * @qiov: the buffers to fill with read data
199      * @flags: currently unused, always 0
200      *
201      * @offset and @bytes will be a multiple of 'request_alignment',
202      * but the length of individual @qiov elements does not have to
203      * be a multiple.
204      *
205      * @bytes will always equal the total size of @qiov, and will be
206      * no larger than 'max_transfer'.
207      *
208      * The buffer in @qiov may point directly to guest memory.
209      */
210     int coroutine_fn (*bdrv_co_preadv)(BlockDriverState *bs,
211         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags);
212     int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
213         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int flags);
214     /**
215      * @offset: position in bytes to write at
216      * @bytes: number of bytes to write
217      * @qiov: the buffers containing data to write
218      * @flags: zero or more bits allowed by 'supported_write_flags'
219      *
220      * @offset and @bytes will be a multiple of 'request_alignment',
221      * but the length of individual @qiov elements does not have to
222      * be a multiple.
223      *
224      * @bytes will always equal the total size of @qiov, and will be
225      * no larger than 'max_transfer'.
226      *
227      * The buffer in @qiov may point directly to guest memory.
228      */
229     int coroutine_fn (*bdrv_co_pwritev)(BlockDriverState *bs,
230         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags);
231 
232     /*
233      * Efficiently zero a region of the disk image.  Typically an image format
234      * would use a compact metadata representation to implement this.  This
235      * function pointer may be NULL or return -ENOSUP and .bdrv_co_writev()
236      * will be called instead.
237      */
238     int coroutine_fn (*bdrv_co_pwrite_zeroes)(BlockDriverState *bs,
239         int64_t offset, int bytes, BdrvRequestFlags flags);
240     int coroutine_fn (*bdrv_co_pdiscard)(BlockDriverState *bs,
241         int64_t offset, int bytes);
242 
243     /* Map [offset, offset + nbytes) range onto a child of @bs to copy from,
244      * and invoke bdrv_co_copy_range_from(child, ...), or invoke
245      * bdrv_co_copy_range_to() if @bs is the leaf child to copy data from.
246      *
247      * See the comment of bdrv_co_copy_range for the parameter and return value
248      * semantics.
249      */
250     int coroutine_fn (*bdrv_co_copy_range_from)(BlockDriverState *bs,
251                                                 BdrvChild *src,
252                                                 uint64_t offset,
253                                                 BdrvChild *dst,
254                                                 uint64_t dst_offset,
255                                                 uint64_t bytes,
256                                                 BdrvRequestFlags read_flags,
257                                                 BdrvRequestFlags write_flags);
258 
259     /* Map [offset, offset + nbytes) range onto a child of bs to copy data to,
260      * and invoke bdrv_co_copy_range_to(child, src, ...), or perform the copy
261      * operation if @bs is the leaf and @src has the same BlockDriver.  Return
262      * -ENOTSUP if @bs is the leaf but @src has a different BlockDriver.
263      *
264      * See the comment of bdrv_co_copy_range for the parameter and return value
265      * semantics.
266      */
267     int coroutine_fn (*bdrv_co_copy_range_to)(BlockDriverState *bs,
268                                               BdrvChild *src,
269                                               uint64_t src_offset,
270                                               BdrvChild *dst,
271                                               uint64_t dst_offset,
272                                               uint64_t bytes,
273                                               BdrvRequestFlags read_flags,
274                                               BdrvRequestFlags write_flags);
275 
276     /*
277      * Building block for bdrv_block_status[_above] and
278      * bdrv_is_allocated[_above].  The driver should answer only
279      * according to the current layer, and should only need to set
280      * BDRV_BLOCK_DATA, BDRV_BLOCK_ZERO, BDRV_BLOCK_OFFSET_VALID,
281      * and/or BDRV_BLOCK_RAW; if the current layer defers to a backing
282      * layer, the result should be 0 (and not BDRV_BLOCK_ZERO).  See
283      * block.h for the overall meaning of the bits.  As a hint, the
284      * flag want_zero is true if the caller cares more about precise
285      * mappings (favor accurate _OFFSET_VALID/_ZERO) or false for
286      * overall allocation (favor larger *pnum, perhaps by reporting
287      * _DATA instead of _ZERO).  The block layer guarantees input
288      * clamped to bdrv_getlength() and aligned to request_alignment,
289      * as well as non-NULL pnum, map, and file; in turn, the driver
290      * must return an error or set pnum to an aligned non-zero value.
291      */
292     int coroutine_fn (*bdrv_co_block_status)(BlockDriverState *bs,
293         bool want_zero, int64_t offset, int64_t bytes, int64_t *pnum,
294         int64_t *map, BlockDriverState **file);
295 
296     /*
297      * Invalidate any cached meta-data.
298      */
299     void coroutine_fn (*bdrv_co_invalidate_cache)(BlockDriverState *bs,
300                                                   Error **errp);
301     int (*bdrv_inactivate)(BlockDriverState *bs);
302 
303     /*
304      * Flushes all data for all layers by calling bdrv_co_flush for underlying
305      * layers, if needed. This function is needed for deterministic
306      * synchronization of the flush finishing callback.
307      */
308     int coroutine_fn (*bdrv_co_flush)(BlockDriverState *bs);
309 
310     /*
311      * Flushes all data that was already written to the OS all the way down to
312      * the disk (for example file-posix.c calls fsync()).
313      */
314     int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
315 
316     /*
317      * Flushes all internal caches to the OS. The data may still sit in a
318      * writeback cache of the host OS, but it will survive a crash of the qemu
319      * process.
320      */
321     int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
322 
323     /*
324      * Drivers setting this field must be able to work with just a plain
325      * filename with '<protocol_name>:' as a prefix, and no other options.
326      * Options may be extracted from the filename by implementing
327      * bdrv_parse_filename.
328      */
329     const char *protocol_name;
330     int coroutine_fn (*bdrv_co_truncate)(BlockDriverState *bs, int64_t offset,
331                                          PreallocMode prealloc, Error **errp);
332 
333     int64_t (*bdrv_getlength)(BlockDriverState *bs);
334     bool has_variable_length;
335     int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
336     BlockMeasureInfo *(*bdrv_measure)(QemuOpts *opts, BlockDriverState *in_bs,
337                                       Error **errp);
338 
339     int coroutine_fn (*bdrv_co_pwritev_compressed)(BlockDriverState *bs,
340         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov);
341 
342     int (*bdrv_snapshot_create)(BlockDriverState *bs,
343                                 QEMUSnapshotInfo *sn_info);
344     int (*bdrv_snapshot_goto)(BlockDriverState *bs,
345                               const char *snapshot_id);
346     int (*bdrv_snapshot_delete)(BlockDriverState *bs,
347                                 const char *snapshot_id,
348                                 const char *name,
349                                 Error **errp);
350     int (*bdrv_snapshot_list)(BlockDriverState *bs,
351                               QEMUSnapshotInfo **psn_info);
352     int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
353                                   const char *snapshot_id,
354                                   const char *name,
355                                   Error **errp);
356     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
357     ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs,
358                                                  Error **errp);
359 
360     int coroutine_fn (*bdrv_save_vmstate)(BlockDriverState *bs,
361                                           QEMUIOVector *qiov,
362                                           int64_t pos);
363     int coroutine_fn (*bdrv_load_vmstate)(BlockDriverState *bs,
364                                           QEMUIOVector *qiov,
365                                           int64_t pos);
366 
367     int (*bdrv_change_backing_file)(BlockDriverState *bs,
368         const char *backing_file, const char *backing_fmt);
369 
370     /* removable device specific */
371     bool (*bdrv_is_inserted)(BlockDriverState *bs);
372     void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
373     void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
374 
375     /* to control generic scsi devices */
376     BlockAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
377         unsigned long int req, void *buf,
378         BlockCompletionFunc *cb, void *opaque);
379     int coroutine_fn (*bdrv_co_ioctl)(BlockDriverState *bs,
380                                       unsigned long int req, void *buf);
381 
382     /* List of options for creating images, terminated by name == NULL */
383     QemuOptsList *create_opts;
384 
385     /*
386      * Returns 0 for completed check, -errno for internal errors.
387      * The check results are stored in result.
388      */
389     int coroutine_fn (*bdrv_co_check)(BlockDriverState *bs,
390                                       BdrvCheckResult *result,
391                                       BdrvCheckMode fix);
392 
393     int (*bdrv_amend_options)(BlockDriverState *bs, QemuOpts *opts,
394                               BlockDriverAmendStatusCB *status_cb,
395                               void *cb_opaque,
396                               Error **errp);
397 
398     void (*bdrv_debug_event)(BlockDriverState *bs, BlkdebugEvent event);
399 
400     /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
401     int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
402         const char *tag);
403     int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs,
404         const char *tag);
405     int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);
406     bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);
407 
408     void (*bdrv_refresh_limits)(BlockDriverState *bs, Error **errp);
409 
410     /*
411      * Returns 1 if newly created images are guaranteed to contain only
412      * zeros, 0 otherwise.
413      */
414     int (*bdrv_has_zero_init)(BlockDriverState *bs);
415 
416     /* Remove fd handlers, timers, and other event loop callbacks so the event
417      * loop is no longer in use.  Called with no in-flight requests and in
418      * depth-first traversal order with parents before child nodes.
419      */
420     void (*bdrv_detach_aio_context)(BlockDriverState *bs);
421 
422     /* Add fd handlers, timers, and other event loop callbacks so I/O requests
423      * can be processed again.  Called with no in-flight requests and in
424      * depth-first traversal order with child nodes before parent nodes.
425      */
426     void (*bdrv_attach_aio_context)(BlockDriverState *bs,
427                                     AioContext *new_context);
428 
429     /* io queue for linux-aio */
430     void (*bdrv_io_plug)(BlockDriverState *bs);
431     void (*bdrv_io_unplug)(BlockDriverState *bs);
432 
433     /**
434      * Try to get @bs's logical and physical block size.
435      * On success, store them in @bsz and return zero.
436      * On failure, return negative errno.
437      */
438     int (*bdrv_probe_blocksizes)(BlockDriverState *bs, BlockSizes *bsz);
439     /**
440      * Try to get @bs's geometry (cyls, heads, sectors)
441      * On success, store them in @geo and return 0.
442      * On failure return -errno.
443      * Only drivers that want to override guest geometry implement this
444      * callback; see hd_geometry_guess().
445      */
446     int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo);
447 
448     /**
449      * bdrv_co_drain_begin is called if implemented in the beginning of a
450      * drain operation to drain and stop any internal sources of requests in
451      * the driver.
452      * bdrv_co_drain_end is called if implemented at the end of the drain.
453      *
454      * They should be used by the driver to e.g. manage scheduled I/O
455      * requests, or toggle an internal state. After the end of the drain new
456      * requests will continue normally.
457      */
458     void coroutine_fn (*bdrv_co_drain_begin)(BlockDriverState *bs);
459     void coroutine_fn (*bdrv_co_drain_end)(BlockDriverState *bs);
460 
461     void (*bdrv_add_child)(BlockDriverState *parent, BlockDriverState *child,
462                            Error **errp);
463     void (*bdrv_del_child)(BlockDriverState *parent, BdrvChild *child,
464                            Error **errp);
465 
466     /**
467      * Informs the block driver that a permission change is intended. The
468      * driver checks whether the change is permissible and may take other
469      * preparations for the change (e.g. get file system locks). This operation
470      * is always followed either by a call to either .bdrv_set_perm or
471      * .bdrv_abort_perm_update.
472      *
473      * Checks whether the requested set of cumulative permissions in @perm
474      * can be granted for accessing @bs and whether no other users are using
475      * permissions other than those given in @shared (both arguments take
476      * BLK_PERM_* bitmasks).
477      *
478      * If both conditions are met, 0 is returned. Otherwise, -errno is returned
479      * and errp is set to an error describing the conflict.
480      */
481     int (*bdrv_check_perm)(BlockDriverState *bs, uint64_t perm,
482                            uint64_t shared, Error **errp);
483 
484     /**
485      * Called to inform the driver that the set of cumulative set of used
486      * permissions for @bs has changed to @perm, and the set of sharable
487      * permission to @shared. The driver can use this to propagate changes to
488      * its children (i.e. request permissions only if a parent actually needs
489      * them).
490      *
491      * This function is only invoked after bdrv_check_perm(), so block drivers
492      * may rely on preparations made in their .bdrv_check_perm implementation.
493      */
494     void (*bdrv_set_perm)(BlockDriverState *bs, uint64_t perm, uint64_t shared);
495 
496     /*
497      * Called to inform the driver that after a previous bdrv_check_perm()
498      * call, the permission update is not performed and any preparations made
499      * for it (e.g. taken file locks) need to be undone.
500      *
501      * This function can be called even for nodes that never saw a
502      * bdrv_check_perm() call. It is a no-op then.
503      */
504     void (*bdrv_abort_perm_update)(BlockDriverState *bs);
505 
506     /**
507      * Returns in @nperm and @nshared the permissions that the driver for @bs
508      * needs on its child @c, based on the cumulative permissions requested by
509      * the parents in @parent_perm and @parent_shared.
510      *
511      * If @c is NULL, return the permissions for attaching a new child for the
512      * given @role.
513      *
514      * If @reopen_queue is non-NULL, don't return the currently needed
515      * permissions, but those that will be needed after applying the
516      * @reopen_queue.
517      */
518      void (*bdrv_child_perm)(BlockDriverState *bs, BdrvChild *c,
519                              const BdrvChildRole *role,
520                              BlockReopenQueue *reopen_queue,
521                              uint64_t parent_perm, uint64_t parent_shared,
522                              uint64_t *nperm, uint64_t *nshared);
523 
524     /**
525      * Bitmaps should be marked as 'IN_USE' in the image on reopening image
526      * as rw. This handler should realize it. It also should unset readonly
527      * field of BlockDirtyBitmap's in case of success.
528      */
529     int (*bdrv_reopen_bitmaps_rw)(BlockDriverState *bs, Error **errp);
530     bool (*bdrv_can_store_new_dirty_bitmap)(BlockDriverState *bs,
531                                             const char *name,
532                                             uint32_t granularity,
533                                             Error **errp);
534     void (*bdrv_remove_persistent_dirty_bitmap)(BlockDriverState *bs,
535                                                 const char *name,
536                                                 Error **errp);
537 
538     /**
539      * Register/unregister a buffer for I/O. For example, when the driver is
540      * interested to know the memory areas that will later be used in iovs, so
541      * that it can do IOMMU mapping with VFIO etc., in order to get better
542      * performance. In the case of VFIO drivers, this callback is used to do
543      * DMA mapping for hot buffers.
544      */
545     void (*bdrv_register_buf)(BlockDriverState *bs, void *host, size_t size);
546     void (*bdrv_unregister_buf)(BlockDriverState *bs, void *host);
547     QLIST_ENTRY(BlockDriver) list;
548 
549     /* Pointer to a NULL-terminated array of names of strong options
550      * that can be specified for bdrv_open(). A strong option is one
551      * that changes the data of a BDS.
552      * If this pointer is NULL, the array is considered empty.
553      * "filename" and "driver" are always considered strong. */
554     const char *const *strong_runtime_opts;
555 };
556 
557 typedef struct BlockLimits {
558     /* Alignment requirement, in bytes, for offset/length of I/O
559      * requests. Must be a power of 2 less than INT_MAX; defaults to
560      * 1 for drivers with modern byte interfaces, and to 512
561      * otherwise. */
562     uint32_t request_alignment;
563 
564     /* Maximum number of bytes that can be discarded at once (since it
565      * is signed, it must be < 2G, if set). Must be multiple of
566      * pdiscard_alignment, but need not be power of 2. May be 0 if no
567      * inherent 32-bit limit */
568     int32_t max_pdiscard;
569 
570     /* Optimal alignment for discard requests in bytes. A power of 2
571      * is best but not mandatory.  Must be a multiple of
572      * bl.request_alignment, and must be less than max_pdiscard if
573      * that is set. May be 0 if bl.request_alignment is good enough */
574     uint32_t pdiscard_alignment;
575 
576     /* Maximum number of bytes that can zeroized at once (since it is
577      * signed, it must be < 2G, if set). Must be multiple of
578      * pwrite_zeroes_alignment. May be 0 if no inherent 32-bit limit */
579     int32_t max_pwrite_zeroes;
580 
581     /* Optimal alignment for write zeroes requests in bytes. A power
582      * of 2 is best but not mandatory.  Must be a multiple of
583      * bl.request_alignment, and must be less than max_pwrite_zeroes
584      * if that is set. May be 0 if bl.request_alignment is good
585      * enough */
586     uint32_t pwrite_zeroes_alignment;
587 
588     /* Optimal transfer length in bytes.  A power of 2 is best but not
589      * mandatory.  Must be a multiple of bl.request_alignment, or 0 if
590      * no preferred size */
591     uint32_t opt_transfer;
592 
593     /* Maximal transfer length in bytes.  Need not be power of 2, but
594      * must be multiple of opt_transfer and bl.request_alignment, or 0
595      * for no 32-bit limit.  For now, anything larger than INT_MAX is
596      * clamped down. */
597     uint32_t max_transfer;
598 
599     /* memory alignment, in bytes so that no bounce buffer is needed */
600     size_t min_mem_alignment;
601 
602     /* memory alignment, in bytes, for bounce buffer */
603     size_t opt_mem_alignment;
604 
605     /* maximum number of iovec elements */
606     int max_iov;
607 } BlockLimits;
608 
609 typedef struct BdrvOpBlocker BdrvOpBlocker;
610 
611 typedef struct BdrvAioNotifier {
612     void (*attached_aio_context)(AioContext *new_context, void *opaque);
613     void (*detach_aio_context)(void *opaque);
614 
615     void *opaque;
616     bool deleted;
617 
618     QLIST_ENTRY(BdrvAioNotifier) list;
619 } BdrvAioNotifier;
620 
621 struct BdrvChildRole {
622     /* If true, bdrv_replace_node() doesn't change the node this BdrvChild
623      * points to. */
624     bool stay_at_node;
625 
626     /* If true, the parent is a BlockDriverState and bdrv_next_all_states()
627      * will return it. This information is used for drain_all, where every node
628      * will be drained separately, so the drain only needs to be propagated to
629      * non-BDS parents. */
630     bool parent_is_bds;
631 
632     void (*inherit_options)(int *child_flags, QDict *child_options,
633                             int parent_flags, QDict *parent_options);
634 
635     void (*change_media)(BdrvChild *child, bool load);
636     void (*resize)(BdrvChild *child);
637 
638     /* Returns a name that is supposedly more useful for human users than the
639      * node name for identifying the node in question (in particular, a BB
640      * name), or NULL if the parent can't provide a better name. */
641     const char *(*get_name)(BdrvChild *child);
642 
643     /* Returns a malloced string that describes the parent of the child for a
644      * human reader. This could be a node-name, BlockBackend name, qdev ID or
645      * QOM path of the device owning the BlockBackend, job type and ID etc. The
646      * caller is responsible for freeing the memory. */
647     char *(*get_parent_desc)(BdrvChild *child);
648 
649     /*
650      * If this pair of functions is implemented, the parent doesn't issue new
651      * requests after returning from .drained_begin() until .drained_end() is
652      * called.
653      *
654      * These functions must not change the graph (and therefore also must not
655      * call aio_poll(), which could change the graph indirectly).
656      *
657      * Note that this can be nested. If drained_begin() was called twice, new
658      * I/O is allowed only after drained_end() was called twice, too.
659      */
660     void (*drained_begin)(BdrvChild *child);
661     void (*drained_end)(BdrvChild *child);
662 
663     /*
664      * Returns whether the parent has pending requests for the child. This
665      * callback is polled after .drained_begin() has been called until all
666      * activity on the child has stopped.
667      */
668     bool (*drained_poll)(BdrvChild *child);
669 
670     /* Notifies the parent that the child has been activated/inactivated (e.g.
671      * when migration is completing) and it can start/stop requesting
672      * permissions and doing I/O on it. */
673     void (*activate)(BdrvChild *child, Error **errp);
674     int (*inactivate)(BdrvChild *child);
675 
676     void (*attach)(BdrvChild *child);
677     void (*detach)(BdrvChild *child);
678 
679     /* Notifies the parent that the filename of its child has changed (e.g.
680      * because the direct child was removed from the backing chain), so that it
681      * can update its reference. */
682     int (*update_filename)(BdrvChild *child, BlockDriverState *new_base,
683                            const char *filename, Error **errp);
684 };
685 
686 extern const BdrvChildRole child_file;
687 extern const BdrvChildRole child_format;
688 extern const BdrvChildRole child_backing;
689 
690 struct BdrvChild {
691     BlockDriverState *bs;
692     char *name;
693     const BdrvChildRole *role;
694     void *opaque;
695 
696     /**
697      * Granted permissions for operating on this BdrvChild (BLK_PERM_* bitmask)
698      */
699     uint64_t perm;
700 
701     /**
702      * Permissions that can still be granted to other users of @bs while this
703      * BdrvChild is still attached to it. (BLK_PERM_* bitmask)
704      */
705     uint64_t shared_perm;
706 
707     /* backup of permissions during permission update procedure */
708     bool has_backup_perm;
709     uint64_t backup_perm;
710     uint64_t backup_shared_perm;
711 
712     QLIST_ENTRY(BdrvChild) next;
713     QLIST_ENTRY(BdrvChild) next_parent;
714 };
715 
716 /*
717  * Note: the function bdrv_append() copies and swaps contents of
718  * BlockDriverStates, so if you add new fields to this struct, please
719  * inspect bdrv_append() to determine if the new fields need to be
720  * copied as well.
721  */
722 struct BlockDriverState {
723     /* Protected by big QEMU lock or read-only after opening.  No special
724      * locking needed during I/O...
725      */
726     int open_flags; /* flags used to open the file, re-used for re-open */
727     bool read_only; /* if true, the media is read only */
728     bool encrypted; /* if true, the media is encrypted */
729     bool sg;        /* if true, the device is a /dev/sg* */
730     bool probed;    /* if true, format was probed rather than specified */
731     bool force_share; /* if true, always allow all shared permissions */
732     bool implicit;  /* if true, this filter node was automatically inserted */
733 
734     BlockDriver *drv; /* NULL means no media */
735     void *opaque;
736 
737     AioContext *aio_context; /* event loop used for fd handlers, timers, etc */
738     /* long-running tasks intended to always use the same AioContext as this
739      * BDS may register themselves in this list to be notified of changes
740      * regarding this BDS's context */
741     QLIST_HEAD(, BdrvAioNotifier) aio_notifiers;
742     bool walking_aio_notifiers; /* to make removal during iteration safe */
743 
744     char filename[PATH_MAX];
745     char backing_file[PATH_MAX]; /* if non zero, the image is a diff of
746                                     this file image */
747     /* The backing filename indicated by the image header; if we ever
748      * open this file, then this is replaced by the resulting BDS's
749      * filename (i.e. after a bdrv_refresh_filename() run). */
750     char auto_backing_file[PATH_MAX];
751     char backing_format[16]; /* if non-zero and backing_file exists */
752 
753     QDict *full_open_options;
754     char exact_filename[PATH_MAX];
755 
756     BdrvChild *backing;
757     BdrvChild *file;
758 
759     /* I/O Limits */
760     BlockLimits bl;
761 
762     /* Flags honored during pwrite (so far: BDRV_REQ_FUA,
763      * BDRV_REQ_WRITE_UNCHANGED).
764      * If a driver does not support BDRV_REQ_WRITE_UNCHANGED, those
765      * writes will be issued as normal writes without the flag set.
766      * This is important to note for drivers that do not explicitly
767      * request a WRITE permission for their children and instead take
768      * the same permissions as their parent did (this is commonly what
769      * block filters do).  Such drivers have to be aware that the
770      * parent may have taken a WRITE_UNCHANGED permission only and is
771      * issuing such requests.  Drivers either must make sure that
772      * these requests do not result in plain WRITE accesses (usually
773      * by supporting BDRV_REQ_WRITE_UNCHANGED, and then forwarding
774      * every incoming write request as-is, including potentially that
775      * flag), or they have to explicitly take the WRITE permission for
776      * their children. */
777     unsigned int supported_write_flags;
778     /* Flags honored during pwrite_zeroes (so far: BDRV_REQ_FUA,
779      * BDRV_REQ_MAY_UNMAP, BDRV_REQ_WRITE_UNCHANGED) */
780     unsigned int supported_zero_flags;
781 
782     /* the following member gives a name to every node on the bs graph. */
783     char node_name[32];
784     /* element of the list of named nodes building the graph */
785     QTAILQ_ENTRY(BlockDriverState) node_list;
786     /* element of the list of all BlockDriverStates (all_bdrv_states) */
787     QTAILQ_ENTRY(BlockDriverState) bs_list;
788     /* element of the list of monitor-owned BDS */
789     QTAILQ_ENTRY(BlockDriverState) monitor_list;
790     int refcnt;
791 
792     /* operation blockers */
793     QLIST_HEAD(, BdrvOpBlocker) op_blockers[BLOCK_OP_TYPE_MAX];
794 
795     /* long-running background operation */
796     BlockJob *job;
797 
798     /* The node that this node inherited default options from (and a reopen on
799      * which can affect this node by changing these defaults). This is always a
800      * parent node of this node. */
801     BlockDriverState *inherits_from;
802     QLIST_HEAD(, BdrvChild) children;
803     QLIST_HEAD(, BdrvChild) parents;
804 
805     QDict *options;
806     QDict *explicit_options;
807     BlockdevDetectZeroesOptions detect_zeroes;
808 
809     /* The error object in use for blocking operations on backing_hd */
810     Error *backing_blocker;
811 
812     /* Protected by AioContext lock */
813 
814     /* If we are reading a disk image, give its size in sectors.
815      * Generally read-only; it is written to by load_snapshot and
816      * save_snaphost, but the block layer is quiescent during those.
817      */
818     int64_t total_sectors;
819 
820     /* Callback before write request is processed */
821     NotifierWithReturnList before_write_notifiers;
822 
823     /* threshold limit for writes, in bytes. "High water mark". */
824     uint64_t write_threshold_offset;
825     NotifierWithReturn write_threshold_notifier;
826 
827     /* Writing to the list requires the BQL _and_ the dirty_bitmap_mutex.
828      * Reading from the list can be done with either the BQL or the
829      * dirty_bitmap_mutex.  Modifying a bitmap only requires
830      * dirty_bitmap_mutex.  */
831     QemuMutex dirty_bitmap_mutex;
832     QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
833 
834     /* Offset after the highest byte written to */
835     Stat64 wr_highest_offset;
836 
837     /* If true, copy read backing sectors into image.  Can be >1 if more
838      * than one client has requested copy-on-read.  Accessed with atomic
839      * ops.
840      */
841     int copy_on_read;
842 
843     /* number of in-flight requests; overall and serialising.
844      * Accessed with atomic ops.
845      */
846     unsigned int in_flight;
847     unsigned int serialising_in_flight;
848 
849     /* counter for nested bdrv_io_plug.
850      * Accessed with atomic ops.
851     */
852     unsigned io_plugged;
853 
854     /* do we need to tell the quest if we have a volatile write cache? */
855     int enable_write_cache;
856 
857     /* Accessed with atomic ops.  */
858     int quiesce_counter;
859     int recursive_quiesce_counter;
860 
861     unsigned int write_gen;               /* Current data generation */
862 
863     /* Protected by reqs_lock.  */
864     CoMutex reqs_lock;
865     QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
866     CoQueue flush_queue;                  /* Serializing flush queue */
867     bool active_flush_req;                /* Flush request in flight? */
868 
869     /* Only read/written by whoever has set active_flush_req to true.  */
870     unsigned int flushed_gen;             /* Flushed write generation */
871 };
872 
873 struct BlockBackendRootState {
874     int open_flags;
875     bool read_only;
876     BlockdevDetectZeroesOptions detect_zeroes;
877 };
878 
879 typedef enum BlockMirrorBackingMode {
880     /* Reuse the existing backing chain from the source for the target.
881      * - sync=full: Set backing BDS to NULL.
882      * - sync=top:  Use source's backing BDS.
883      * - sync=none: Use source as the backing BDS. */
884     MIRROR_SOURCE_BACKING_CHAIN,
885 
886     /* Open the target's backing chain completely anew */
887     MIRROR_OPEN_BACKING_CHAIN,
888 
889     /* Do not change the target's backing BDS after job completion */
890     MIRROR_LEAVE_BACKING_CHAIN,
891 } BlockMirrorBackingMode;
892 
893 static inline BlockDriverState *backing_bs(BlockDriverState *bs)
894 {
895     return bs->backing ? bs->backing->bs : NULL;
896 }
897 
898 
899 /* Essential block drivers which must always be statically linked into qemu, and
900  * which therefore can be accessed without using bdrv_find_format() */
901 extern BlockDriver bdrv_file;
902 extern BlockDriver bdrv_raw;
903 extern BlockDriver bdrv_qcow2;
904 
905 int coroutine_fn bdrv_co_preadv(BdrvChild *child,
906     int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
907     BdrvRequestFlags flags);
908 int coroutine_fn bdrv_co_pwritev(BdrvChild *child,
909     int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
910     BdrvRequestFlags flags);
911 
912 extern unsigned int bdrv_drain_all_count;
913 void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent);
914 void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent);
915 
916 int get_tmp_filename(char *filename, int size);
917 BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
918                             const char *filename);
919 
920 void bdrv_parse_filename_strip_prefix(const char *filename, const char *prefix,
921                                       QDict *options);
922 
923 
924 /**
925  * bdrv_add_before_write_notifier:
926  *
927  * Register a callback that is invoked before write requests are processed but
928  * after any throttling or waiting for overlapping requests.
929  */
930 void bdrv_add_before_write_notifier(BlockDriverState *bs,
931                                     NotifierWithReturn *notifier);
932 
933 /**
934  * bdrv_detach_aio_context:
935  *
936  * May be called from .bdrv_detach_aio_context() to detach children from the
937  * current #AioContext.  This is only needed by block drivers that manage their
938  * own children.  Both ->file and ->backing are automatically handled and
939  * block drivers should not call this function on them explicitly.
940  */
941 void bdrv_detach_aio_context(BlockDriverState *bs);
942 
943 /**
944  * bdrv_attach_aio_context:
945  *
946  * May be called from .bdrv_attach_aio_context() to attach children to the new
947  * #AioContext.  This is only needed by block drivers that manage their own
948  * children.  Both ->file and ->backing are automatically handled and block
949  * drivers should not call this function on them explicitly.
950  */
951 void bdrv_attach_aio_context(BlockDriverState *bs,
952                              AioContext *new_context);
953 
954 /**
955  * bdrv_add_aio_context_notifier:
956  *
957  * If a long-running job intends to be always run in the same AioContext as a
958  * certain BDS, it may use this function to be notified of changes regarding the
959  * association of the BDS to an AioContext.
960  *
961  * attached_aio_context() is called after the target BDS has been attached to a
962  * new AioContext; detach_aio_context() is called before the target BDS is being
963  * detached from its old AioContext.
964  */
965 void bdrv_add_aio_context_notifier(BlockDriverState *bs,
966         void (*attached_aio_context)(AioContext *new_context, void *opaque),
967         void (*detach_aio_context)(void *opaque), void *opaque);
968 
969 /**
970  * bdrv_remove_aio_context_notifier:
971  *
972  * Unsubscribe of change notifications regarding the BDS's AioContext. The
973  * parameters given here have to be the same as those given to
974  * bdrv_add_aio_context_notifier().
975  */
976 void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
977                                       void (*aio_context_attached)(AioContext *,
978                                                                    void *),
979                                       void (*aio_context_detached)(void *),
980                                       void *opaque);
981 
982 /**
983  * bdrv_wakeup:
984  * @bs: The BlockDriverState for which an I/O operation has been completed.
985  *
986  * Wake up the main thread if it is waiting on BDRV_POLL_WHILE.  During
987  * synchronous I/O on a BlockDriverState that is attached to another
988  * I/O thread, the main thread lets the I/O thread's event loop run,
989  * waiting for the I/O operation to complete.  A bdrv_wakeup will wake
990  * up the main thread if necessary.
991  *
992  * Manual calls to bdrv_wakeup are rarely necessary, because
993  * bdrv_dec_in_flight already calls it.
994  */
995 void bdrv_wakeup(BlockDriverState *bs);
996 
997 #ifdef _WIN32
998 int is_windows_drive(const char *filename);
999 #endif
1000 
1001 /**
1002  * stream_start:
1003  * @job_id: The id of the newly-created job, or %NULL to use the
1004  * device name of @bs.
1005  * @bs: Block device to operate on.
1006  * @base: Block device that will become the new base, or %NULL to
1007  * flatten the whole backing file chain onto @bs.
1008  * @backing_file_str: The file name that will be written to @bs as the
1009  * the new backing file if the job completes. Ignored if @base is %NULL.
1010  * @creation_flags: Flags that control the behavior of the Job lifetime.
1011  *                  See @BlockJobCreateFlags
1012  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1013  * @on_error: The action to take upon error.
1014  * @errp: Error object.
1015  *
1016  * Start a streaming operation on @bs.  Clusters that are unallocated
1017  * in @bs, but allocated in any image between @base and @bs (both
1018  * exclusive) will be written to @bs.  At the end of a successful
1019  * streaming job, the backing file of @bs will be changed to
1020  * @backing_file_str in the written image and to @base in the live
1021  * BlockDriverState.
1022  */
1023 void stream_start(const char *job_id, BlockDriverState *bs,
1024                   BlockDriverState *base, const char *backing_file_str,
1025                   int creation_flags, int64_t speed,
1026                   BlockdevOnError on_error, Error **errp);
1027 
1028 /**
1029  * commit_start:
1030  * @job_id: The id of the newly-created job, or %NULL to use the
1031  * device name of @bs.
1032  * @bs: Active block device.
1033  * @top: Top block device to be committed.
1034  * @base: Block device that will be written into, and become the new top.
1035  * @creation_flags: Flags that control the behavior of the Job lifetime.
1036  *                  See @BlockJobCreateFlags
1037  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1038  * @on_error: The action to take upon error.
1039  * @backing_file_str: String to use as the backing file in @top's overlay
1040  * @filter_node_name: The node name that should be assigned to the filter
1041  * driver that the commit job inserts into the graph above @top. NULL means
1042  * that a node name should be autogenerated.
1043  * @errp: Error object.
1044  *
1045  */
1046 void commit_start(const char *job_id, BlockDriverState *bs,
1047                   BlockDriverState *base, BlockDriverState *top,
1048                   int creation_flags, int64_t speed,
1049                   BlockdevOnError on_error, const char *backing_file_str,
1050                   const char *filter_node_name, Error **errp);
1051 /**
1052  * commit_active_start:
1053  * @job_id: The id of the newly-created job, or %NULL to use the
1054  * device name of @bs.
1055  * @bs: Active block device to be committed.
1056  * @base: Block device that will be written into, and become the new top.
1057  * @creation_flags: Flags that control the behavior of the Job lifetime.
1058  *                  See @BlockJobCreateFlags
1059  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1060  * @on_error: The action to take upon error.
1061  * @filter_node_name: The node name that should be assigned to the filter
1062  * driver that the commit job inserts into the graph above @bs. NULL means that
1063  * a node name should be autogenerated.
1064  * @cb: Completion function for the job.
1065  * @opaque: Opaque pointer value passed to @cb.
1066  * @auto_complete: Auto complete the job.
1067  * @errp: Error object.
1068  *
1069  */
1070 void commit_active_start(const char *job_id, BlockDriverState *bs,
1071                          BlockDriverState *base, int creation_flags,
1072                          int64_t speed, BlockdevOnError on_error,
1073                          const char *filter_node_name,
1074                          BlockCompletionFunc *cb, void *opaque,
1075                          bool auto_complete, Error **errp);
1076 /*
1077  * mirror_start:
1078  * @job_id: The id of the newly-created job, or %NULL to use the
1079  * device name of @bs.
1080  * @bs: Block device to operate on.
1081  * @target: Block device to write to.
1082  * @replaces: Block graph node name to replace once the mirror is done. Can
1083  *            only be used when full mirroring is selected.
1084  * @creation_flags: Flags that control the behavior of the Job lifetime.
1085  *                  See @BlockJobCreateFlags
1086  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1087  * @granularity: The chosen granularity for the dirty bitmap.
1088  * @buf_size: The amount of data that can be in flight at one time.
1089  * @mode: Whether to collapse all images in the chain to the target.
1090  * @backing_mode: How to establish the target's backing chain after completion.
1091  * @on_source_error: The action to take upon error reading from the source.
1092  * @on_target_error: The action to take upon error writing to the target.
1093  * @unmap: Whether to unmap target where source sectors only contain zeroes.
1094  * @filter_node_name: The node name that should be assigned to the filter
1095  * driver that the mirror job inserts into the graph above @bs. NULL means that
1096  * a node name should be autogenerated.
1097  * @copy_mode: When to trigger writes to the target.
1098  * @errp: Error object.
1099  *
1100  * Start a mirroring operation on @bs.  Clusters that are allocated
1101  * in @bs will be written to @target until the job is cancelled or
1102  * manually completed.  At the end of a successful mirroring job,
1103  * @bs will be switched to read from @target.
1104  */
1105 void mirror_start(const char *job_id, BlockDriverState *bs,
1106                   BlockDriverState *target, const char *replaces,
1107                   int creation_flags, int64_t speed,
1108                   uint32_t granularity, int64_t buf_size,
1109                   MirrorSyncMode mode, BlockMirrorBackingMode backing_mode,
1110                   BlockdevOnError on_source_error,
1111                   BlockdevOnError on_target_error,
1112                   bool unmap, const char *filter_node_name,
1113                   MirrorCopyMode copy_mode, Error **errp);
1114 
1115 /*
1116  * backup_job_create:
1117  * @job_id: The id of the newly-created job, or %NULL to use the
1118  * device name of @bs.
1119  * @bs: Block device to operate on.
1120  * @target: Block device to write to.
1121  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
1122  * @sync_mode: What parts of the disk image should be copied to the destination.
1123  * @sync_bitmap: The dirty bitmap if sync_mode is MIRROR_SYNC_MODE_INCREMENTAL.
1124  * @on_source_error: The action to take upon error reading from the source.
1125  * @on_target_error: The action to take upon error writing to the target.
1126  * @creation_flags: Flags that control the behavior of the Job lifetime.
1127  *                  See @BlockJobCreateFlags
1128  * @cb: Completion function for the job.
1129  * @opaque: Opaque pointer value passed to @cb.
1130  * @txn: Transaction that this job is part of (may be NULL).
1131  *
1132  * Create a backup operation on @bs.  Clusters in @bs are written to @target
1133  * until the job is cancelled or manually completed.
1134  */
1135 BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
1136                             BlockDriverState *target, int64_t speed,
1137                             MirrorSyncMode sync_mode,
1138                             BdrvDirtyBitmap *sync_bitmap,
1139                             bool compress,
1140                             BlockdevOnError on_source_error,
1141                             BlockdevOnError on_target_error,
1142                             int creation_flags,
1143                             BlockCompletionFunc *cb, void *opaque,
1144                             JobTxn *txn, Error **errp);
1145 
1146 void hmp_drive_add_node(Monitor *mon, const char *optstr);
1147 
1148 BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
1149                                   const char *child_name,
1150                                   const BdrvChildRole *child_role,
1151                                   uint64_t perm, uint64_t shared_perm,
1152                                   void *opaque, Error **errp);
1153 void bdrv_root_unref_child(BdrvChild *child);
1154 
1155 int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
1156                             Error **errp);
1157 
1158 /* Default implementation for BlockDriver.bdrv_child_perm() that can be used by
1159  * block filters: Forward CONSISTENT_READ, WRITE, WRITE_UNCHANGED and RESIZE to
1160  * all children */
1161 void bdrv_filter_default_perms(BlockDriverState *bs, BdrvChild *c,
1162                                const BdrvChildRole *role,
1163                                BlockReopenQueue *reopen_queue,
1164                                uint64_t perm, uint64_t shared,
1165                                uint64_t *nperm, uint64_t *nshared);
1166 
1167 /* Default implementation for BlockDriver.bdrv_child_perm() that can be used by
1168  * (non-raw) image formats: Like above for bs->backing, but for bs->file it
1169  * requires WRITE | RESIZE for read-write images, always requires
1170  * CONSISTENT_READ and doesn't share WRITE. */
1171 void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c,
1172                                const BdrvChildRole *role,
1173                                BlockReopenQueue *reopen_queue,
1174                                uint64_t perm, uint64_t shared,
1175                                uint64_t *nperm, uint64_t *nshared);
1176 
1177 /*
1178  * Default implementation for drivers to pass bdrv_co_block_status() to
1179  * their file.
1180  */
1181 int coroutine_fn bdrv_co_block_status_from_file(BlockDriverState *bs,
1182                                                 bool want_zero,
1183                                                 int64_t offset,
1184                                                 int64_t bytes,
1185                                                 int64_t *pnum,
1186                                                 int64_t *map,
1187                                                 BlockDriverState **file);
1188 /*
1189  * Default implementation for drivers to pass bdrv_co_block_status() to
1190  * their backing file.
1191  */
1192 int coroutine_fn bdrv_co_block_status_from_backing(BlockDriverState *bs,
1193                                                    bool want_zero,
1194                                                    int64_t offset,
1195                                                    int64_t bytes,
1196                                                    int64_t *pnum,
1197                                                    int64_t *map,
1198                                                    BlockDriverState **file);
1199 const char *bdrv_get_parent_name(const BlockDriverState *bs);
1200 void blk_dev_change_media_cb(BlockBackend *blk, bool load, Error **errp);
1201 bool blk_dev_has_removable_media(BlockBackend *blk);
1202 bool blk_dev_has_tray(BlockBackend *blk);
1203 void blk_dev_eject_request(BlockBackend *blk, bool force);
1204 bool blk_dev_is_tray_open(BlockBackend *blk);
1205 bool blk_dev_is_medium_locked(BlockBackend *blk);
1206 
1207 void bdrv_set_dirty(BlockDriverState *bs, int64_t offset, int64_t bytes);
1208 
1209 void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out);
1210 void bdrv_restore_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *backup);
1211 
1212 void bdrv_inc_in_flight(BlockDriverState *bs);
1213 void bdrv_dec_in_flight(BlockDriverState *bs);
1214 
1215 void blockdev_close_all_bdrv_states(void);
1216 
1217 int coroutine_fn bdrv_co_copy_range_from(BdrvChild *src, uint64_t src_offset,
1218                                          BdrvChild *dst, uint64_t dst_offset,
1219                                          uint64_t bytes,
1220                                          BdrvRequestFlags read_flags,
1221                                          BdrvRequestFlags write_flags);
1222 int coroutine_fn bdrv_co_copy_range_to(BdrvChild *src, uint64_t src_offset,
1223                                        BdrvChild *dst, uint64_t dst_offset,
1224                                        uint64_t bytes,
1225                                        BdrvRequestFlags read_flags,
1226                                        BdrvRequestFlags write_flags);
1227 
1228 int refresh_total_sectors(BlockDriverState *bs, int64_t hint);
1229 
1230 #endif /* BLOCK_INT_H */
1231