xref: /openbmc/qemu/include/block/block.h (revision 891f8dcd)
1 #ifndef BLOCK_H
2 #define BLOCK_H
3 
4 #include "block/aio.h"
5 #include "qemu/iov.h"
6 #include "qemu/option.h"
7 #include "qemu/coroutine.h"
8 #include "block/accounting.h"
9 #include "block/dirty-bitmap.h"
10 #include "qapi/qmp/qobject.h"
11 #include "qapi-types.h"
12 #include "qemu/hbitmap.h"
13 
14 /* block.c */
15 typedef struct BlockDriver BlockDriver;
16 typedef struct BlockJob BlockJob;
17 typedef struct BdrvChild BdrvChild;
18 typedef struct BdrvChildRole BdrvChildRole;
19 typedef struct BlockJobTxn BlockJobTxn;
20 
21 typedef struct BlockDriverInfo {
22     /* in bytes, 0 if irrelevant */
23     int cluster_size;
24     /* offset at which the VM state can be saved (0 if not possible) */
25     int64_t vm_state_offset;
26     bool is_dirty;
27     /*
28      * True if unallocated blocks read back as zeroes. This is equivalent
29      * to the LBPRZ flag in the SCSI logical block provisioning page.
30      */
31     bool unallocated_blocks_are_zero;
32     /*
33      * True if the driver can optimize writing zeroes by unmapping
34      * sectors. This is equivalent to the BLKDISCARDZEROES ioctl in Linux
35      * with the difference that in qemu a discard is allowed to silently
36      * fail. Therefore we have to use bdrv_write_zeroes with the
37      * BDRV_REQ_MAY_UNMAP flag for an optimized zero write with unmapping.
38      * After this call the driver has to guarantee that the contents read
39      * back as zero. It is additionally required that the block device is
40      * opened with BDRV_O_UNMAP flag for this to work.
41      */
42     bool can_write_zeroes_with_unmap;
43     /*
44      * True if this block driver only supports compressed writes
45      */
46     bool needs_compressed_writes;
47 } BlockDriverInfo;
48 
49 typedef struct BlockFragInfo {
50     uint64_t allocated_clusters;
51     uint64_t total_clusters;
52     uint64_t fragmented_clusters;
53     uint64_t compressed_clusters;
54 } BlockFragInfo;
55 
56 typedef enum {
57     BDRV_REQ_COPY_ON_READ       = 0x1,
58     BDRV_REQ_ZERO_WRITE         = 0x2,
59     /* The BDRV_REQ_MAY_UNMAP flag is used to indicate that the block driver
60      * is allowed to optimize a write zeroes request by unmapping (discarding)
61      * blocks if it is guaranteed that the result will read back as
62      * zeroes. The flag is only passed to the driver if the block device is
63      * opened with BDRV_O_UNMAP.
64      */
65     BDRV_REQ_MAY_UNMAP          = 0x4,
66     BDRV_REQ_NO_SERIALISING     = 0x8,
67     BDRV_REQ_FUA                = 0x10,
68 } BdrvRequestFlags;
69 
70 typedef struct BlockSizes {
71     uint32_t phys;
72     uint32_t log;
73 } BlockSizes;
74 
75 typedef struct HDGeometry {
76     uint32_t heads;
77     uint32_t sectors;
78     uint32_t cylinders;
79 } HDGeometry;
80 
81 #define BDRV_O_RDWR        0x0002
82 #define BDRV_O_SNAPSHOT    0x0008 /* open the file read only and save writes in a snapshot */
83 #define BDRV_O_TEMPORARY   0x0010 /* delete the file after use */
84 #define BDRV_O_NOCACHE     0x0020 /* do not use the host page cache */
85 #define BDRV_O_NATIVE_AIO  0x0080 /* use native AIO instead of the thread pool */
86 #define BDRV_O_NO_BACKING  0x0100 /* don't open the backing file */
87 #define BDRV_O_NO_FLUSH    0x0200 /* disable flushing on this disk */
88 #define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
89 #define BDRV_O_INACTIVE    0x0800  /* consistency hint for migration handoff */
90 #define BDRV_O_CHECK       0x1000  /* open solely for consistency check */
91 #define BDRV_O_ALLOW_RDWR  0x2000  /* allow reopen to change from r/o to r/w */
92 #define BDRV_O_UNMAP       0x4000  /* execute guest UNMAP/TRIM operations */
93 #define BDRV_O_PROTOCOL    0x8000  /* if no block driver is explicitly given:
94                                       select an appropriate protocol driver,
95                                       ignoring the format layer */
96 #define BDRV_O_NO_IO       0x10000 /* don't initialize for I/O */
97 
98 #define BDRV_O_CACHE_MASK  (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)
99 
100 
101 /* Option names of options parsed by the block layer */
102 
103 #define BDRV_OPT_CACHE_WB       "cache.writeback"
104 #define BDRV_OPT_CACHE_DIRECT   "cache.direct"
105 #define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
106 
107 
108 #define BDRV_SECTOR_BITS   9
109 #define BDRV_SECTOR_SIZE   (1ULL << BDRV_SECTOR_BITS)
110 #define BDRV_SECTOR_MASK   ~(BDRV_SECTOR_SIZE - 1)
111 
112 #define BDRV_REQUEST_MAX_SECTORS MIN(SIZE_MAX >> BDRV_SECTOR_BITS, \
113                                      INT_MAX >> BDRV_SECTOR_BITS)
114 
115 /*
116  * Allocation status flags
117  * BDRV_BLOCK_DATA: data is read from a file returned by bdrv_get_block_status.
118  * BDRV_BLOCK_ZERO: sectors read as zero
119  * BDRV_BLOCK_OFFSET_VALID: sector stored as raw data in a file returned by
120  *                          bdrv_get_block_status.
121  * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
122  *                       layer (as opposed to the backing file)
123  * BDRV_BLOCK_RAW: used internally to indicate that the request
124  *                 was answered by the raw driver and that one
125  *                 should look in bs->file directly.
126  *
127  * If BDRV_BLOCK_OFFSET_VALID is set, bits 9-62 represent the offset in
128  * bs->file where sector data can be read from as raw data.
129  *
130  * DATA == 0 && ZERO == 0 means that data is read from backing_hd if present.
131  *
132  * DATA ZERO OFFSET_VALID
133  *  t    t        t       sectors read as zero, bs->file is zero at offset
134  *  t    f        t       sectors read as valid from bs->file at offset
135  *  f    t        t       sectors preallocated, read as zero, bs->file not
136  *                        necessarily zero at offset
137  *  f    f        t       sectors preallocated but read from backing_hd,
138  *                        bs->file contains garbage at offset
139  *  t    t        f       sectors preallocated, read as zero, unknown offset
140  *  t    f        f       sectors read from unknown file or offset
141  *  f    t        f       not allocated or unknown offset, read as zero
142  *  f    f        f       not allocated or unknown offset, read from backing_hd
143  */
144 #define BDRV_BLOCK_DATA         0x01
145 #define BDRV_BLOCK_ZERO         0x02
146 #define BDRV_BLOCK_OFFSET_VALID 0x04
147 #define BDRV_BLOCK_RAW          0x08
148 #define BDRV_BLOCK_ALLOCATED    0x10
149 #define BDRV_BLOCK_OFFSET_MASK  BDRV_SECTOR_MASK
150 
151 typedef QSIMPLEQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue;
152 
153 typedef struct BDRVReopenState {
154     BlockDriverState *bs;
155     int flags;
156     QDict *options;
157     QDict *explicit_options;
158     void *opaque;
159 } BDRVReopenState;
160 
161 /*
162  * Block operation types
163  */
164 typedef enum BlockOpType {
165     BLOCK_OP_TYPE_BACKUP_SOURCE,
166     BLOCK_OP_TYPE_BACKUP_TARGET,
167     BLOCK_OP_TYPE_CHANGE,
168     BLOCK_OP_TYPE_COMMIT_SOURCE,
169     BLOCK_OP_TYPE_COMMIT_TARGET,
170     BLOCK_OP_TYPE_DATAPLANE,
171     BLOCK_OP_TYPE_DRIVE_DEL,
172     BLOCK_OP_TYPE_EJECT,
173     BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,
174     BLOCK_OP_TYPE_INTERNAL_SNAPSHOT,
175     BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
176     BLOCK_OP_TYPE_MIRROR_SOURCE,
177     BLOCK_OP_TYPE_MIRROR_TARGET,
178     BLOCK_OP_TYPE_RESIZE,
179     BLOCK_OP_TYPE_STREAM,
180     BLOCK_OP_TYPE_REPLACE,
181     BLOCK_OP_TYPE_MAX,
182 } BlockOpType;
183 
184 void bdrv_info_print(Monitor *mon, const QObject *data);
185 void bdrv_info(Monitor *mon, QObject **ret_data);
186 void bdrv_stats_print(Monitor *mon, const QObject *data);
187 void bdrv_info_stats(Monitor *mon, QObject **ret_data);
188 
189 /* disk I/O throttling */
190 void bdrv_init(void);
191 void bdrv_init_with_whitelist(void);
192 bool bdrv_uses_whitelist(void);
193 BlockDriver *bdrv_find_protocol(const char *filename,
194                                 bool allow_protocol_prefix,
195                                 Error **errp);
196 BlockDriver *bdrv_find_format(const char *format_name);
197 int bdrv_create(BlockDriver *drv, const char* filename,
198                 QemuOpts *opts, Error **errp);
199 int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp);
200 BlockDriverState *bdrv_new(void);
201 void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top);
202 void bdrv_replace_in_backing_chain(BlockDriverState *old,
203                                    BlockDriverState *new);
204 
205 int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough);
206 int bdrv_parse_discard_flags(const char *mode, int *flags);
207 BdrvChild *bdrv_open_child(const char *filename,
208                            QDict *options, const char *bdref_key,
209                            BlockDriverState* parent,
210                            const BdrvChildRole *child_role,
211                            bool allow_none, Error **errp);
212 void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd);
213 int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
214                            const char *bdref_key, Error **errp);
215 BlockDriverState *bdrv_open(const char *filename, const char *reference,
216                             QDict *options, int flags, Error **errp);
217 BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
218                                     BlockDriverState *bs,
219                                     QDict *options, int flags);
220 int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp);
221 int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp);
222 int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
223                         BlockReopenQueue *queue, Error **errp);
224 void bdrv_reopen_commit(BDRVReopenState *reopen_state);
225 void bdrv_reopen_abort(BDRVReopenState *reopen_state);
226 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
227               uint8_t *buf, int nb_sectors);
228 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
229                const uint8_t *buf, int nb_sectors);
230 int bdrv_write_zeroes(BlockDriverState *bs, int64_t sector_num,
231                int nb_sectors, BdrvRequestFlags flags);
232 BlockAIOCB *bdrv_aio_write_zeroes(BlockDriverState *bs, int64_t sector_num,
233                                   int nb_sectors, BdrvRequestFlags flags,
234                                   BlockCompletionFunc *cb, void *opaque);
235 int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags);
236 int bdrv_pread(BlockDriverState *bs, int64_t offset,
237                void *buf, int count);
238 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
239                 const void *buf, int count);
240 int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov);
241 int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
242     const void *buf, int count);
243 int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
244     int nb_sectors, QEMUIOVector *qiov);
245 int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
246     int nb_sectors, QEMUIOVector *qiov);
247 /*
248  * Efficiently zero a region of the disk image.  Note that this is a regular
249  * I/O request like read or write and should have a reasonable size.  This
250  * function is not suitable for zeroing the entire image in a single request
251  * because it may allocate memory for the entire region.
252  */
253 int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs, int64_t sector_num,
254     int nb_sectors, BdrvRequestFlags flags);
255 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
256     const char *backing_file);
257 int bdrv_get_backing_file_depth(BlockDriverState *bs);
258 void bdrv_refresh_filename(BlockDriverState *bs);
259 int bdrv_truncate(BlockDriverState *bs, int64_t offset);
260 int64_t bdrv_nb_sectors(BlockDriverState *bs);
261 int64_t bdrv_getlength(BlockDriverState *bs);
262 int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);
263 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
264 void bdrv_refresh_limits(BlockDriverState *bs, Error **errp);
265 int bdrv_commit(BlockDriverState *bs);
266 int bdrv_change_backing_file(BlockDriverState *bs,
267     const char *backing_file, const char *backing_fmt);
268 void bdrv_register(BlockDriver *bdrv);
269 int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
270                            BlockDriverState *base,
271                            const char *backing_file_str);
272 BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
273                                     BlockDriverState *bs);
274 BlockDriverState *bdrv_find_base(BlockDriverState *bs);
275 
276 
277 typedef struct BdrvCheckResult {
278     int corruptions;
279     int leaks;
280     int check_errors;
281     int corruptions_fixed;
282     int leaks_fixed;
283     int64_t image_end_offset;
284     BlockFragInfo bfi;
285 } BdrvCheckResult;
286 
287 typedef enum {
288     BDRV_FIX_LEAKS    = 1,
289     BDRV_FIX_ERRORS   = 2,
290 } BdrvCheckMode;
291 
292 int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix);
293 
294 /* The units of offset and total_work_size may be chosen arbitrarily by the
295  * block driver; total_work_size may change during the course of the amendment
296  * operation */
297 typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
298                                       int64_t total_work_size, void *opaque);
299 int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
300                        BlockDriverAmendStatusCB *status_cb, void *cb_opaque);
301 
302 /* external snapshots */
303 bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
304                                       BlockDriverState *candidate);
305 bool bdrv_is_first_non_filter(BlockDriverState *candidate);
306 
307 /* check if a named node can be replaced when doing drive-mirror */
308 BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
309                                         const char *node_name, Error **errp);
310 
311 /* async block I/O */
312 BlockAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
313                            QEMUIOVector *iov, int nb_sectors,
314                            BlockCompletionFunc *cb, void *opaque);
315 BlockAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
316                             QEMUIOVector *iov, int nb_sectors,
317                             BlockCompletionFunc *cb, void *opaque);
318 BlockAIOCB *bdrv_aio_flush(BlockDriverState *bs,
319                            BlockCompletionFunc *cb, void *opaque);
320 BlockAIOCB *bdrv_aio_discard(BlockDriverState *bs,
321                              int64_t sector_num, int nb_sectors,
322                              BlockCompletionFunc *cb, void *opaque);
323 void bdrv_aio_cancel(BlockAIOCB *acb);
324 void bdrv_aio_cancel_async(BlockAIOCB *acb);
325 
326 typedef struct BlockRequest {
327     /* Fields to be filled by caller */
328     union {
329         struct {
330             int64_t sector;
331             int nb_sectors;
332             int flags;
333             QEMUIOVector *qiov;
334         };
335         struct {
336             int req;
337             void *buf;
338         };
339     };
340     BlockCompletionFunc *cb;
341     void *opaque;
342 
343     /* Filled by block layer */
344     int error;
345 } BlockRequest;
346 
347 /* sg packet commands */
348 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf);
349 BlockAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
350         unsigned long int req, void *buf,
351         BlockCompletionFunc *cb, void *opaque);
352 
353 /* Invalidate any cached metadata used by image formats */
354 void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp);
355 void bdrv_invalidate_cache_all(Error **errp);
356 int bdrv_inactivate_all(void);
357 
358 /* Ensure contents are flushed to disk.  */
359 int bdrv_flush(BlockDriverState *bs);
360 int coroutine_fn bdrv_co_flush(BlockDriverState *bs);
361 void bdrv_close_all(void);
362 void bdrv_drain(BlockDriverState *bs);
363 void coroutine_fn bdrv_co_drain(BlockDriverState *bs);
364 void bdrv_drain_all(void);
365 
366 int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
367 int bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
368 int bdrv_has_zero_init_1(BlockDriverState *bs);
369 int bdrv_has_zero_init(BlockDriverState *bs);
370 bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs);
371 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
372 int64_t bdrv_get_block_status(BlockDriverState *bs, int64_t sector_num,
373                               int nb_sectors, int *pnum,
374                               BlockDriverState **file);
375 int64_t bdrv_get_block_status_above(BlockDriverState *bs,
376                                     BlockDriverState *base,
377                                     int64_t sector_num,
378                                     int nb_sectors, int *pnum,
379                                     BlockDriverState **file);
380 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
381                       int *pnum);
382 int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
383                             int64_t sector_num, int nb_sectors, int *pnum);
384 
385 int bdrv_is_read_only(BlockDriverState *bs);
386 int bdrv_is_sg(BlockDriverState *bs);
387 bool bdrv_is_inserted(BlockDriverState *bs);
388 int bdrv_media_changed(BlockDriverState *bs);
389 void bdrv_lock_medium(BlockDriverState *bs, bool locked);
390 void bdrv_eject(BlockDriverState *bs, bool eject_flag);
391 const char *bdrv_get_format_name(BlockDriverState *bs);
392 BlockDriverState *bdrv_find_node(const char *node_name);
393 BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp);
394 BlockDriverState *bdrv_lookup_bs(const char *device,
395                                  const char *node_name,
396                                  Error **errp);
397 bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
398 BlockDriverState *bdrv_next_node(BlockDriverState *bs);
399 
400 typedef struct BdrvNextIterator {
401     enum {
402         BDRV_NEXT_BACKEND_ROOTS,
403         BDRV_NEXT_MONITOR_OWNED,
404     } phase;
405     BlockBackend *blk;
406     BlockDriverState *bs;
407 } BdrvNextIterator;
408 
409 BlockDriverState *bdrv_first(BdrvNextIterator *it);
410 BlockDriverState *bdrv_next(BdrvNextIterator *it);
411 
412 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
413 int bdrv_is_encrypted(BlockDriverState *bs);
414 int bdrv_key_required(BlockDriverState *bs);
415 int bdrv_set_key(BlockDriverState *bs, const char *key);
416 void bdrv_add_key(BlockDriverState *bs, const char *key, Error **errp);
417 int bdrv_query_missing_keys(void);
418 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
419                          void *opaque);
420 const char *bdrv_get_node_name(const BlockDriverState *bs);
421 const char *bdrv_get_device_name(const BlockDriverState *bs);
422 const char *bdrv_get_device_or_node_name(const BlockDriverState *bs);
423 int bdrv_get_flags(BlockDriverState *bs);
424 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
425                           const uint8_t *buf, int nb_sectors);
426 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
427 ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs);
428 void bdrv_round_to_clusters(BlockDriverState *bs,
429                             int64_t sector_num, int nb_sectors,
430                             int64_t *cluster_sector_num,
431                             int *cluster_nb_sectors);
432 
433 const char *bdrv_get_encrypted_filename(BlockDriverState *bs);
434 void bdrv_get_backing_filename(BlockDriverState *bs,
435                                char *filename, int filename_size);
436 void bdrv_get_full_backing_filename(BlockDriverState *bs,
437                                     char *dest, size_t sz, Error **errp);
438 void bdrv_get_full_backing_filename_from_filename(const char *backed,
439                                                   const char *backing,
440                                                   char *dest, size_t sz,
441                                                   Error **errp);
442 int bdrv_is_snapshot(BlockDriverState *bs);
443 
444 int path_has_protocol(const char *path);
445 int path_is_absolute(const char *path);
446 void path_combine(char *dest, int dest_size,
447                   const char *base_path,
448                   const char *filename);
449 
450 int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
451 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
452                       int64_t pos, int size);
453 
454 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
455                       int64_t pos, int size);
456 
457 void bdrv_img_create(const char *filename, const char *fmt,
458                      const char *base_filename, const char *base_fmt,
459                      char *options, uint64_t img_size, int flags,
460                      Error **errp, bool quiet);
461 
462 /* Returns the alignment in bytes that is required so that no bounce buffer
463  * is required throughout the stack */
464 size_t bdrv_min_mem_align(BlockDriverState *bs);
465 /* Returns optimal alignment in bytes for bounce buffer */
466 size_t bdrv_opt_mem_align(BlockDriverState *bs);
467 void *qemu_blockalign(BlockDriverState *bs, size_t size);
468 void *qemu_blockalign0(BlockDriverState *bs, size_t size);
469 void *qemu_try_blockalign(BlockDriverState *bs, size_t size);
470 void *qemu_try_blockalign0(BlockDriverState *bs, size_t size);
471 bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov);
472 
473 void bdrv_enable_copy_on_read(BlockDriverState *bs);
474 void bdrv_disable_copy_on_read(BlockDriverState *bs);
475 
476 void bdrv_ref(BlockDriverState *bs);
477 void bdrv_unref(BlockDriverState *bs);
478 void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
479 BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
480                              BlockDriverState *child_bs,
481                              const char *child_name,
482                              const BdrvChildRole *child_role);
483 
484 bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
485 void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
486 void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
487 void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
488 void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
489 bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
490 
491 #define BLKDBG_EVENT(child, evt) \
492     do { \
493         if (child) { \
494             bdrv_debug_event(child->bs, evt); \
495         } \
496     } while (0)
497 
498 void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event);
499 
500 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
501                            const char *tag);
502 int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
503 int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
504 bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
505 
506 /**
507  * bdrv_get_aio_context:
508  *
509  * Returns: the currently bound #AioContext
510  */
511 AioContext *bdrv_get_aio_context(BlockDriverState *bs);
512 
513 /**
514  * bdrv_set_aio_context:
515  *
516  * Changes the #AioContext used for fd handlers, timers, and BHs by this
517  * BlockDriverState and all its children.
518  *
519  * This function must be called with iothread lock held.
520  */
521 void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context);
522 int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
523 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
524 
525 void bdrv_io_plug(BlockDriverState *bs);
526 void bdrv_io_unplug(BlockDriverState *bs);
527 void bdrv_io_unplugged_begin(BlockDriverState *bs);
528 void bdrv_io_unplugged_end(BlockDriverState *bs);
529 
530 /**
531  * bdrv_drained_begin:
532  *
533  * Begin a quiesced section for exclusive access to the BDS, by disabling
534  * external request sources including NBD server and device model. Note that
535  * this doesn't block timers or coroutines from submitting more requests, which
536  * means block_job_pause is still necessary.
537  *
538  * This function can be recursive.
539  */
540 void bdrv_drained_begin(BlockDriverState *bs);
541 
542 /**
543  * bdrv_drained_end:
544  *
545  * End a quiescent section started by bdrv_drained_begin().
546  */
547 void bdrv_drained_end(BlockDriverState *bs);
548 
549 void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child,
550                     Error **errp);
551 void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
552 
553 #endif
554