xref: /openbmc/qemu/include/block/block.h (revision 8692aa29)
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_pwrite_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 
69     /* Mask of valid flags */
70     BDRV_REQ_MASK               = 0x1f,
71 } BdrvRequestFlags;
72 
73 typedef struct BlockSizes {
74     uint32_t phys;
75     uint32_t log;
76 } BlockSizes;
77 
78 typedef struct HDGeometry {
79     uint32_t heads;
80     uint32_t sectors;
81     uint32_t cylinders;
82 } HDGeometry;
83 
84 #define BDRV_O_RDWR        0x0002
85 #define BDRV_O_SNAPSHOT    0x0008 /* open the file read only and save writes in a snapshot */
86 #define BDRV_O_TEMPORARY   0x0010 /* delete the file after use */
87 #define BDRV_O_NOCACHE     0x0020 /* do not use the host page cache */
88 #define BDRV_O_NATIVE_AIO  0x0080 /* use native AIO instead of the thread pool */
89 #define BDRV_O_NO_BACKING  0x0100 /* don't open the backing file */
90 #define BDRV_O_NO_FLUSH    0x0200 /* disable flushing on this disk */
91 #define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
92 #define BDRV_O_INACTIVE    0x0800  /* consistency hint for migration handoff */
93 #define BDRV_O_CHECK       0x1000  /* open solely for consistency check */
94 #define BDRV_O_ALLOW_RDWR  0x2000  /* allow reopen to change from r/o to r/w */
95 #define BDRV_O_UNMAP       0x4000  /* execute guest UNMAP/TRIM operations */
96 #define BDRV_O_PROTOCOL    0x8000  /* if no block driver is explicitly given:
97                                       select an appropriate protocol driver,
98                                       ignoring the format layer */
99 #define BDRV_O_NO_IO       0x10000 /* don't initialize for I/O */
100 
101 #define BDRV_O_CACHE_MASK  (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)
102 
103 
104 /* Option names of options parsed by the block layer */
105 
106 #define BDRV_OPT_CACHE_WB       "cache.writeback"
107 #define BDRV_OPT_CACHE_DIRECT   "cache.direct"
108 #define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
109 
110 
111 #define BDRV_SECTOR_BITS   9
112 #define BDRV_SECTOR_SIZE   (1ULL << BDRV_SECTOR_BITS)
113 #define BDRV_SECTOR_MASK   ~(BDRV_SECTOR_SIZE - 1)
114 
115 #define BDRV_REQUEST_MAX_SECTORS MIN(SIZE_MAX >> BDRV_SECTOR_BITS, \
116                                      INT_MAX >> BDRV_SECTOR_BITS)
117 
118 /*
119  * Allocation status flags
120  * BDRV_BLOCK_DATA: data is read from a file returned by bdrv_get_block_status.
121  * BDRV_BLOCK_ZERO: sectors read as zero
122  * BDRV_BLOCK_OFFSET_VALID: sector stored as raw data in a file returned by
123  *                          bdrv_get_block_status.
124  * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
125  *                       layer (as opposed to the backing file)
126  * BDRV_BLOCK_RAW: used internally to indicate that the request
127  *                 was answered by the raw driver and that one
128  *                 should look in bs->file directly.
129  *
130  * If BDRV_BLOCK_OFFSET_VALID is set, bits 9-62 represent the offset in
131  * bs->file where sector data can be read from as raw data.
132  *
133  * DATA == 0 && ZERO == 0 means that data is read from backing_hd if present.
134  *
135  * DATA ZERO OFFSET_VALID
136  *  t    t        t       sectors read as zero, bs->file is zero at offset
137  *  t    f        t       sectors read as valid from bs->file at offset
138  *  f    t        t       sectors preallocated, read as zero, bs->file not
139  *                        necessarily zero at offset
140  *  f    f        t       sectors preallocated but read from backing_hd,
141  *                        bs->file contains garbage at offset
142  *  t    t        f       sectors preallocated, read as zero, unknown offset
143  *  t    f        f       sectors read from unknown file or offset
144  *  f    t        f       not allocated or unknown offset, read as zero
145  *  f    f        f       not allocated or unknown offset, read from backing_hd
146  */
147 #define BDRV_BLOCK_DATA         0x01
148 #define BDRV_BLOCK_ZERO         0x02
149 #define BDRV_BLOCK_OFFSET_VALID 0x04
150 #define BDRV_BLOCK_RAW          0x08
151 #define BDRV_BLOCK_ALLOCATED    0x10
152 #define BDRV_BLOCK_OFFSET_MASK  BDRV_SECTOR_MASK
153 
154 typedef QSIMPLEQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue;
155 
156 typedef struct BDRVReopenState {
157     BlockDriverState *bs;
158     int flags;
159     QDict *options;
160     QDict *explicit_options;
161     void *opaque;
162 } BDRVReopenState;
163 
164 /*
165  * Block operation types
166  */
167 typedef enum BlockOpType {
168     BLOCK_OP_TYPE_BACKUP_SOURCE,
169     BLOCK_OP_TYPE_BACKUP_TARGET,
170     BLOCK_OP_TYPE_CHANGE,
171     BLOCK_OP_TYPE_COMMIT_SOURCE,
172     BLOCK_OP_TYPE_COMMIT_TARGET,
173     BLOCK_OP_TYPE_DATAPLANE,
174     BLOCK_OP_TYPE_DRIVE_DEL,
175     BLOCK_OP_TYPE_EJECT,
176     BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,
177     BLOCK_OP_TYPE_INTERNAL_SNAPSHOT,
178     BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
179     BLOCK_OP_TYPE_MIRROR_SOURCE,
180     BLOCK_OP_TYPE_MIRROR_TARGET,
181     BLOCK_OP_TYPE_RESIZE,
182     BLOCK_OP_TYPE_STREAM,
183     BLOCK_OP_TYPE_REPLACE,
184     BLOCK_OP_TYPE_MAX,
185 } BlockOpType;
186 
187 void bdrv_info_print(Monitor *mon, const QObject *data);
188 void bdrv_info(Monitor *mon, QObject **ret_data);
189 void bdrv_stats_print(Monitor *mon, const QObject *data);
190 void bdrv_info_stats(Monitor *mon, QObject **ret_data);
191 
192 /* disk I/O throttling */
193 void bdrv_init(void);
194 void bdrv_init_with_whitelist(void);
195 bool bdrv_uses_whitelist(void);
196 BlockDriver *bdrv_find_protocol(const char *filename,
197                                 bool allow_protocol_prefix,
198                                 Error **errp);
199 BlockDriver *bdrv_find_format(const char *format_name);
200 int bdrv_create(BlockDriver *drv, const char* filename,
201                 QemuOpts *opts, Error **errp);
202 int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp);
203 BlockDriverState *bdrv_new(void);
204 void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top);
205 void bdrv_replace_in_backing_chain(BlockDriverState *old,
206                                    BlockDriverState *new);
207 
208 int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough);
209 int bdrv_parse_discard_flags(const char *mode, int *flags);
210 BdrvChild *bdrv_open_child(const char *filename,
211                            QDict *options, const char *bdref_key,
212                            BlockDriverState* parent,
213                            const BdrvChildRole *child_role,
214                            bool allow_none, Error **errp);
215 void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd);
216 int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
217                            const char *bdref_key, Error **errp);
218 BlockDriverState *bdrv_open(const char *filename, const char *reference,
219                             QDict *options, int flags, Error **errp);
220 BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
221                                     BlockDriverState *bs,
222                                     QDict *options, int flags);
223 int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp);
224 int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp);
225 int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
226                         BlockReopenQueue *queue, Error **errp);
227 void bdrv_reopen_commit(BDRVReopenState *reopen_state);
228 void bdrv_reopen_abort(BDRVReopenState *reopen_state);
229 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
230               uint8_t *buf, int nb_sectors);
231 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
232                const uint8_t *buf, int nb_sectors);
233 int bdrv_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
234                        int count, BdrvRequestFlags flags);
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_preadv(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov);
239 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
240                 const void *buf, int count);
241 int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov);
242 int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
243     const void *buf, int count);
244 int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
245     int nb_sectors, QEMUIOVector *qiov);
246 int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
247     int nb_sectors, QEMUIOVector *qiov);
248 /*
249  * Efficiently zero a region of the disk image.  Note that this is a regular
250  * I/O request like read or write and should have a reasonable size.  This
251  * function is not suitable for zeroing the entire image in a single request
252  * because it may allocate memory for the entire region.
253  */
254 int coroutine_fn bdrv_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
255     int count, BdrvRequestFlags flags);
256 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
257     const char *backing_file);
258 int bdrv_get_backing_file_depth(BlockDriverState *bs);
259 void bdrv_refresh_filename(BlockDriverState *bs);
260 int bdrv_truncate(BlockDriverState *bs, int64_t offset);
261 int64_t bdrv_nb_sectors(BlockDriverState *bs);
262 int64_t bdrv_getlength(BlockDriverState *bs);
263 int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);
264 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
265 void bdrv_refresh_limits(BlockDriverState *bs, Error **errp);
266 int bdrv_commit(BlockDriverState *bs);
267 int bdrv_change_backing_file(BlockDriverState *bs,
268     const char *backing_file, const char *backing_fmt);
269 void bdrv_register(BlockDriver *bdrv);
270 int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
271                            BlockDriverState *base,
272                            const char *backing_file_str);
273 BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
274                                     BlockDriverState *bs);
275 BlockDriverState *bdrv_find_base(BlockDriverState *bs);
276 
277 
278 typedef struct BdrvCheckResult {
279     int corruptions;
280     int leaks;
281     int check_errors;
282     int corruptions_fixed;
283     int leaks_fixed;
284     int64_t image_end_offset;
285     BlockFragInfo bfi;
286 } BdrvCheckResult;
287 
288 typedef enum {
289     BDRV_FIX_LEAKS    = 1,
290     BDRV_FIX_ERRORS   = 2,
291 } BdrvCheckMode;
292 
293 int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix);
294 
295 /* The units of offset and total_work_size may be chosen arbitrarily by the
296  * block driver; total_work_size may change during the course of the amendment
297  * operation */
298 typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
299                                       int64_t total_work_size, void *opaque);
300 int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
301                        BlockDriverAmendStatusCB *status_cb, void *cb_opaque);
302 
303 /* external snapshots */
304 bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
305                                       BlockDriverState *candidate);
306 bool bdrv_is_first_non_filter(BlockDriverState *candidate);
307 
308 /* check if a named node can be replaced when doing drive-mirror */
309 BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
310                                         const char *node_name, Error **errp);
311 
312 /* async block I/O */
313 BlockAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
314                            QEMUIOVector *iov, int nb_sectors,
315                            BlockCompletionFunc *cb, void *opaque);
316 BlockAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
317                             QEMUIOVector *iov, int nb_sectors,
318                             BlockCompletionFunc *cb, void *opaque);
319 BlockAIOCB *bdrv_aio_flush(BlockDriverState *bs,
320                            BlockCompletionFunc *cb, void *opaque);
321 BlockAIOCB *bdrv_aio_discard(BlockDriverState *bs,
322                              int64_t sector_num, int nb_sectors,
323                              BlockCompletionFunc *cb, void *opaque);
324 void bdrv_aio_cancel(BlockAIOCB *acb);
325 void bdrv_aio_cancel_async(BlockAIOCB *acb);
326 
327 /* sg packet commands */
328 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf);
329 BlockAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
330         unsigned long int req, void *buf,
331         BlockCompletionFunc *cb, void *opaque);
332 
333 /* Invalidate any cached metadata used by image formats */
334 void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp);
335 void bdrv_invalidate_cache_all(Error **errp);
336 int bdrv_inactivate_all(void);
337 
338 /* Ensure contents are flushed to disk.  */
339 int bdrv_flush(BlockDriverState *bs);
340 int coroutine_fn bdrv_co_flush(BlockDriverState *bs);
341 void bdrv_close_all(void);
342 void bdrv_drain(BlockDriverState *bs);
343 void coroutine_fn bdrv_co_drain(BlockDriverState *bs);
344 void bdrv_drain_all(void);
345 
346 int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
347 int bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
348 int bdrv_has_zero_init_1(BlockDriverState *bs);
349 int bdrv_has_zero_init(BlockDriverState *bs);
350 bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs);
351 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
352 int64_t bdrv_get_block_status(BlockDriverState *bs, int64_t sector_num,
353                               int nb_sectors, int *pnum,
354                               BlockDriverState **file);
355 int64_t bdrv_get_block_status_above(BlockDriverState *bs,
356                                     BlockDriverState *base,
357                                     int64_t sector_num,
358                                     int nb_sectors, int *pnum,
359                                     BlockDriverState **file);
360 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
361                       int *pnum);
362 int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
363                             int64_t sector_num, int nb_sectors, int *pnum);
364 
365 int bdrv_is_read_only(BlockDriverState *bs);
366 int bdrv_is_sg(BlockDriverState *bs);
367 bool bdrv_is_inserted(BlockDriverState *bs);
368 int bdrv_media_changed(BlockDriverState *bs);
369 void bdrv_lock_medium(BlockDriverState *bs, bool locked);
370 void bdrv_eject(BlockDriverState *bs, bool eject_flag);
371 const char *bdrv_get_format_name(BlockDriverState *bs);
372 BlockDriverState *bdrv_find_node(const char *node_name);
373 BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp);
374 BlockDriverState *bdrv_lookup_bs(const char *device,
375                                  const char *node_name,
376                                  Error **errp);
377 bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
378 BlockDriverState *bdrv_next_node(BlockDriverState *bs);
379 
380 typedef struct BdrvNextIterator {
381     enum {
382         BDRV_NEXT_BACKEND_ROOTS,
383         BDRV_NEXT_MONITOR_OWNED,
384     } phase;
385     BlockBackend *blk;
386     BlockDriverState *bs;
387 } BdrvNextIterator;
388 
389 BlockDriverState *bdrv_first(BdrvNextIterator *it);
390 BlockDriverState *bdrv_next(BdrvNextIterator *it);
391 
392 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
393 int bdrv_is_encrypted(BlockDriverState *bs);
394 int bdrv_key_required(BlockDriverState *bs);
395 int bdrv_set_key(BlockDriverState *bs, const char *key);
396 void bdrv_add_key(BlockDriverState *bs, const char *key, Error **errp);
397 int bdrv_query_missing_keys(void);
398 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
399                          void *opaque);
400 const char *bdrv_get_node_name(const BlockDriverState *bs);
401 const char *bdrv_get_device_name(const BlockDriverState *bs);
402 const char *bdrv_get_device_or_node_name(const BlockDriverState *bs);
403 int bdrv_get_flags(BlockDriverState *bs);
404 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
405                           const uint8_t *buf, int nb_sectors);
406 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
407 ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs);
408 void bdrv_round_sectors_to_clusters(BlockDriverState *bs,
409                                     int64_t sector_num, int nb_sectors,
410                                     int64_t *cluster_sector_num,
411                                     int *cluster_nb_sectors);
412 void bdrv_round_to_clusters(BlockDriverState *bs,
413                             int64_t offset, unsigned int bytes,
414                             int64_t *cluster_offset,
415                             unsigned int *cluster_bytes);
416 
417 const char *bdrv_get_encrypted_filename(BlockDriverState *bs);
418 void bdrv_get_backing_filename(BlockDriverState *bs,
419                                char *filename, int filename_size);
420 void bdrv_get_full_backing_filename(BlockDriverState *bs,
421                                     char *dest, size_t sz, Error **errp);
422 void bdrv_get_full_backing_filename_from_filename(const char *backed,
423                                                   const char *backing,
424                                                   char *dest, size_t sz,
425                                                   Error **errp);
426 int bdrv_is_snapshot(BlockDriverState *bs);
427 
428 int path_has_protocol(const char *path);
429 int path_is_absolute(const char *path);
430 void path_combine(char *dest, int dest_size,
431                   const char *base_path,
432                   const char *filename);
433 
434 int bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
435 int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
436 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
437                       int64_t pos, int size);
438 
439 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
440                       int64_t pos, int size);
441 
442 void bdrv_img_create(const char *filename, const char *fmt,
443                      const char *base_filename, const char *base_fmt,
444                      char *options, uint64_t img_size, int flags,
445                      Error **errp, bool quiet);
446 
447 /* Returns the alignment in bytes that is required so that no bounce buffer
448  * is required throughout the stack */
449 size_t bdrv_min_mem_align(BlockDriverState *bs);
450 /* Returns optimal alignment in bytes for bounce buffer */
451 size_t bdrv_opt_mem_align(BlockDriverState *bs);
452 void *qemu_blockalign(BlockDriverState *bs, size_t size);
453 void *qemu_blockalign0(BlockDriverState *bs, size_t size);
454 void *qemu_try_blockalign(BlockDriverState *bs, size_t size);
455 void *qemu_try_blockalign0(BlockDriverState *bs, size_t size);
456 bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov);
457 
458 void bdrv_enable_copy_on_read(BlockDriverState *bs);
459 void bdrv_disable_copy_on_read(BlockDriverState *bs);
460 
461 void bdrv_ref(BlockDriverState *bs);
462 void bdrv_unref(BlockDriverState *bs);
463 void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
464 BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
465                              BlockDriverState *child_bs,
466                              const char *child_name,
467                              const BdrvChildRole *child_role);
468 
469 bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
470 void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
471 void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
472 void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
473 void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
474 bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
475 
476 #define BLKDBG_EVENT(child, evt) \
477     do { \
478         if (child) { \
479             bdrv_debug_event(child->bs, evt); \
480         } \
481     } while (0)
482 
483 void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event);
484 
485 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
486                            const char *tag);
487 int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
488 int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
489 bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
490 
491 /**
492  * bdrv_get_aio_context:
493  *
494  * Returns: the currently bound #AioContext
495  */
496 AioContext *bdrv_get_aio_context(BlockDriverState *bs);
497 
498 /**
499  * bdrv_set_aio_context:
500  *
501  * Changes the #AioContext used for fd handlers, timers, and BHs by this
502  * BlockDriverState and all its children.
503  *
504  * This function must be called with iothread lock held.
505  */
506 void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context);
507 int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
508 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
509 
510 void bdrv_io_plug(BlockDriverState *bs);
511 void bdrv_io_unplug(BlockDriverState *bs);
512 void bdrv_io_unplugged_begin(BlockDriverState *bs);
513 void bdrv_io_unplugged_end(BlockDriverState *bs);
514 
515 /**
516  * bdrv_drained_begin:
517  *
518  * Begin a quiesced section for exclusive access to the BDS, by disabling
519  * external request sources including NBD server and device model. Note that
520  * this doesn't block timers or coroutines from submitting more requests, which
521  * means block_job_pause is still necessary.
522  *
523  * This function can be recursive.
524  */
525 void bdrv_drained_begin(BlockDriverState *bs);
526 
527 /**
528  * bdrv_drained_end:
529  *
530  * End a quiescent section started by bdrv_drained_begin().
531  */
532 void bdrv_drained_end(BlockDriverState *bs);
533 
534 void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child,
535                     Error **errp);
536 void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
537 
538 #endif
539