xref: /openbmc/qemu/include/block/block.h (revision cea25275)
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     BDRV_REQ_WRITE_COMPRESSED   = 0x20,
69 
70     /* Mask of valid flags */
71     BDRV_REQ_MASK               = 0x3f,
72 } BdrvRequestFlags;
73 
74 typedef struct BlockSizes {
75     uint32_t phys;
76     uint32_t log;
77 } BlockSizes;
78 
79 typedef struct HDGeometry {
80     uint32_t heads;
81     uint32_t sectors;
82     uint32_t cylinders;
83 } HDGeometry;
84 
85 #define BDRV_O_RDWR        0x0002
86 #define BDRV_O_SNAPSHOT    0x0008 /* open the file read only and save writes in a snapshot */
87 #define BDRV_O_TEMPORARY   0x0010 /* delete the file after use */
88 #define BDRV_O_NOCACHE     0x0020 /* do not use the host page cache */
89 #define BDRV_O_NATIVE_AIO  0x0080 /* use native AIO instead of the thread pool */
90 #define BDRV_O_NO_BACKING  0x0100 /* don't open the backing file */
91 #define BDRV_O_NO_FLUSH    0x0200 /* disable flushing on this disk */
92 #define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
93 #define BDRV_O_INACTIVE    0x0800  /* consistency hint for migration handoff */
94 #define BDRV_O_CHECK       0x1000  /* open solely for consistency check */
95 #define BDRV_O_ALLOW_RDWR  0x2000  /* allow reopen to change from r/o to r/w */
96 #define BDRV_O_UNMAP       0x4000  /* execute guest UNMAP/TRIM operations */
97 #define BDRV_O_PROTOCOL    0x8000  /* if no block driver is explicitly given:
98                                       select an appropriate protocol driver,
99                                       ignoring the format layer */
100 #define BDRV_O_NO_IO       0x10000 /* don't initialize for I/O */
101 
102 #define BDRV_O_CACHE_MASK  (BDRV_O_NOCACHE | BDRV_O_NO_FLUSH)
103 
104 
105 /* Option names of options parsed by the block layer */
106 
107 #define BDRV_OPT_CACHE_WB       "cache.writeback"
108 #define BDRV_OPT_CACHE_DIRECT   "cache.direct"
109 #define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
110 
111 
112 #define BDRV_SECTOR_BITS   9
113 #define BDRV_SECTOR_SIZE   (1ULL << BDRV_SECTOR_BITS)
114 #define BDRV_SECTOR_MASK   ~(BDRV_SECTOR_SIZE - 1)
115 
116 #define BDRV_REQUEST_MAX_SECTORS MIN(SIZE_MAX >> BDRV_SECTOR_BITS, \
117                                      INT_MAX >> BDRV_SECTOR_BITS)
118 
119 /*
120  * Allocation status flags
121  * BDRV_BLOCK_DATA: data is read from a file returned by bdrv_get_block_status.
122  * BDRV_BLOCK_ZERO: sectors read as zero
123  * BDRV_BLOCK_OFFSET_VALID: sector stored as raw data in a file returned by
124  *                          bdrv_get_block_status.
125  * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
126  *                       layer (as opposed to the backing file)
127  * BDRV_BLOCK_RAW: used internally to indicate that the request
128  *                 was answered by the raw driver and that one
129  *                 should look in bs->file directly.
130  *
131  * If BDRV_BLOCK_OFFSET_VALID is set, bits 9-62 represent the offset in
132  * bs->file where sector data can be read from as raw data.
133  *
134  * DATA == 0 && ZERO == 0 means that data is read from backing_hd if present.
135  *
136  * DATA ZERO OFFSET_VALID
137  *  t    t        t       sectors read as zero, bs->file is zero at offset
138  *  t    f        t       sectors read as valid from bs->file at offset
139  *  f    t        t       sectors preallocated, read as zero, bs->file not
140  *                        necessarily zero at offset
141  *  f    f        t       sectors preallocated but read from backing_hd,
142  *                        bs->file contains garbage at offset
143  *  t    t        f       sectors preallocated, read as zero, unknown offset
144  *  t    f        f       sectors read from unknown file or offset
145  *  f    t        f       not allocated or unknown offset, read as zero
146  *  f    f        f       not allocated or unknown offset, read from backing_hd
147  */
148 #define BDRV_BLOCK_DATA         0x01
149 #define BDRV_BLOCK_ZERO         0x02
150 #define BDRV_BLOCK_OFFSET_VALID 0x04
151 #define BDRV_BLOCK_RAW          0x08
152 #define BDRV_BLOCK_ALLOCATED    0x10
153 #define BDRV_BLOCK_OFFSET_MASK  BDRV_SECTOR_MASK
154 
155 typedef QSIMPLEQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue;
156 
157 typedef struct BDRVReopenState {
158     BlockDriverState *bs;
159     int flags;
160     QDict *options;
161     QDict *explicit_options;
162     void *opaque;
163 } BDRVReopenState;
164 
165 /*
166  * Block operation types
167  */
168 typedef enum BlockOpType {
169     BLOCK_OP_TYPE_BACKUP_SOURCE,
170     BLOCK_OP_TYPE_BACKUP_TARGET,
171     BLOCK_OP_TYPE_CHANGE,
172     BLOCK_OP_TYPE_COMMIT_SOURCE,
173     BLOCK_OP_TYPE_COMMIT_TARGET,
174     BLOCK_OP_TYPE_DATAPLANE,
175     BLOCK_OP_TYPE_DRIVE_DEL,
176     BLOCK_OP_TYPE_EJECT,
177     BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,
178     BLOCK_OP_TYPE_INTERNAL_SNAPSHOT,
179     BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
180     BLOCK_OP_TYPE_MIRROR_SOURCE,
181     BLOCK_OP_TYPE_MIRROR_TARGET,
182     BLOCK_OP_TYPE_RESIZE,
183     BLOCK_OP_TYPE_STREAM,
184     BLOCK_OP_TYPE_REPLACE,
185     BLOCK_OP_TYPE_MAX,
186 } BlockOpType;
187 
188 /* disk I/O throttling */
189 void bdrv_init(void);
190 void bdrv_init_with_whitelist(void);
191 bool bdrv_uses_whitelist(void);
192 BlockDriver *bdrv_find_protocol(const char *filename,
193                                 bool allow_protocol_prefix,
194                                 Error **errp);
195 BlockDriver *bdrv_find_format(const char *format_name);
196 int bdrv_create(BlockDriver *drv, const char* filename,
197                 QemuOpts *opts, Error **errp);
198 int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp);
199 BlockDriverState *bdrv_new(void);
200 void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top);
201 void bdrv_replace_in_backing_chain(BlockDriverState *old,
202                                    BlockDriverState *new);
203 
204 int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough);
205 int bdrv_parse_discard_flags(const char *mode, int *flags);
206 BdrvChild *bdrv_open_child(const char *filename,
207                            QDict *options, const char *bdref_key,
208                            BlockDriverState* parent,
209                            const BdrvChildRole *child_role,
210                            bool allow_none, Error **errp);
211 void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd);
212 int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
213                            const char *bdref_key, Error **errp);
214 BlockDriverState *bdrv_open(const char *filename, const char *reference,
215                             QDict *options, int flags, Error **errp);
216 BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
217                                     BlockDriverState *bs,
218                                     QDict *options, int flags);
219 int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp);
220 int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp);
221 int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
222                         BlockReopenQueue *queue, Error **errp);
223 void bdrv_reopen_commit(BDRVReopenState *reopen_state);
224 void bdrv_reopen_abort(BDRVReopenState *reopen_state);
225 int bdrv_read(BdrvChild *child, int64_t sector_num,
226               uint8_t *buf, int nb_sectors);
227 int bdrv_write(BdrvChild *child, int64_t sector_num,
228                const uint8_t *buf, int nb_sectors);
229 int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
230                        int count, BdrvRequestFlags flags);
231 int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags);
232 int bdrv_pread(BdrvChild *child, int64_t offset, void *buf, int bytes);
233 int bdrv_preadv(BdrvChild *child, int64_t offset, QEMUIOVector *qiov);
234 int bdrv_pwrite(BdrvChild *child, int64_t offset, const void *buf, int bytes);
235 int bdrv_pwritev(BdrvChild *child, int64_t offset, QEMUIOVector *qiov);
236 int bdrv_pwrite_sync(BdrvChild *child, int64_t offset,
237                      const void *buf, int count);
238 int coroutine_fn bdrv_co_readv(BdrvChild *child, int64_t sector_num,
239                                int nb_sectors, QEMUIOVector *qiov);
240 int coroutine_fn bdrv_co_writev(BdrvChild *child, int64_t sector_num,
241                                int nb_sectors, QEMUIOVector *qiov);
242 /*
243  * Efficiently zero a region of the disk image.  Note that this is a regular
244  * I/O request like read or write and should have a reasonable size.  This
245  * function is not suitable for zeroing the entire image in a single request
246  * because it may allocate memory for the entire region.
247  */
248 int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset,
249                                        int count, BdrvRequestFlags flags);
250 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
251     const char *backing_file);
252 int bdrv_get_backing_file_depth(BlockDriverState *bs);
253 void bdrv_refresh_filename(BlockDriverState *bs);
254 int bdrv_truncate(BlockDriverState *bs, int64_t offset);
255 int64_t bdrv_nb_sectors(BlockDriverState *bs);
256 int64_t bdrv_getlength(BlockDriverState *bs);
257 int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);
258 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
259 void bdrv_refresh_limits(BlockDriverState *bs, Error **errp);
260 int bdrv_commit(BlockDriverState *bs);
261 int bdrv_change_backing_file(BlockDriverState *bs,
262     const char *backing_file, const char *backing_fmt);
263 void bdrv_register(BlockDriver *bdrv);
264 int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
265                            BlockDriverState *base,
266                            const char *backing_file_str);
267 BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
268                                     BlockDriverState *bs);
269 BlockDriverState *bdrv_find_base(BlockDriverState *bs);
270 
271 
272 typedef struct BdrvCheckResult {
273     int corruptions;
274     int leaks;
275     int check_errors;
276     int corruptions_fixed;
277     int leaks_fixed;
278     int64_t image_end_offset;
279     BlockFragInfo bfi;
280 } BdrvCheckResult;
281 
282 typedef enum {
283     BDRV_FIX_LEAKS    = 1,
284     BDRV_FIX_ERRORS   = 2,
285 } BdrvCheckMode;
286 
287 int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix);
288 
289 /* The units of offset and total_work_size may be chosen arbitrarily by the
290  * block driver; total_work_size may change during the course of the amendment
291  * operation */
292 typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
293                                       int64_t total_work_size, void *opaque);
294 int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
295                        BlockDriverAmendStatusCB *status_cb, void *cb_opaque);
296 
297 /* external snapshots */
298 bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
299                                       BlockDriverState *candidate);
300 bool bdrv_is_first_non_filter(BlockDriverState *candidate);
301 
302 /* check if a named node can be replaced when doing drive-mirror */
303 BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
304                                         const char *node_name, Error **errp);
305 
306 /* async block I/O */
307 BlockAIOCB *bdrv_aio_readv(BdrvChild *child, int64_t sector_num,
308                            QEMUIOVector *iov, int nb_sectors,
309                            BlockCompletionFunc *cb, void *opaque);
310 BlockAIOCB *bdrv_aio_writev(BdrvChild *child, int64_t sector_num,
311                             QEMUIOVector *iov, int nb_sectors,
312                             BlockCompletionFunc *cb, void *opaque);
313 BlockAIOCB *bdrv_aio_flush(BlockDriverState *bs,
314                            BlockCompletionFunc *cb, void *opaque);
315 BlockAIOCB *bdrv_aio_pdiscard(BlockDriverState *bs,
316                               int64_t offset, int count,
317                               BlockCompletionFunc *cb, void *opaque);
318 void bdrv_aio_cancel(BlockAIOCB *acb);
319 void bdrv_aio_cancel_async(BlockAIOCB *acb);
320 
321 /* sg packet commands */
322 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf);
323 BlockAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
324         unsigned long int req, void *buf,
325         BlockCompletionFunc *cb, void *opaque);
326 
327 /* Invalidate any cached metadata used by image formats */
328 void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp);
329 void bdrv_invalidate_cache_all(Error **errp);
330 int bdrv_inactivate_all(void);
331 
332 /* Ensure contents are flushed to disk.  */
333 int bdrv_flush(BlockDriverState *bs);
334 int coroutine_fn bdrv_co_flush(BlockDriverState *bs);
335 void bdrv_close_all(void);
336 void bdrv_drain(BlockDriverState *bs);
337 void coroutine_fn bdrv_co_drain(BlockDriverState *bs);
338 void bdrv_drain_all(void);
339 
340 int bdrv_pdiscard(BlockDriverState *bs, int64_t offset, int count);
341 int bdrv_co_pdiscard(BlockDriverState *bs, int64_t offset, int count);
342 int bdrv_has_zero_init_1(BlockDriverState *bs);
343 int bdrv_has_zero_init(BlockDriverState *bs);
344 bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs);
345 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
346 int64_t bdrv_get_block_status(BlockDriverState *bs, int64_t sector_num,
347                               int nb_sectors, int *pnum,
348                               BlockDriverState **file);
349 int64_t bdrv_get_block_status_above(BlockDriverState *bs,
350                                     BlockDriverState *base,
351                                     int64_t sector_num,
352                                     int nb_sectors, int *pnum,
353                                     BlockDriverState **file);
354 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
355                       int *pnum);
356 int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
357                             int64_t sector_num, int nb_sectors, int *pnum);
358 
359 bool bdrv_is_read_only(BlockDriverState *bs);
360 bool bdrv_is_sg(BlockDriverState *bs);
361 bool bdrv_is_inserted(BlockDriverState *bs);
362 int bdrv_media_changed(BlockDriverState *bs);
363 void bdrv_lock_medium(BlockDriverState *bs, bool locked);
364 void bdrv_eject(BlockDriverState *bs, bool eject_flag);
365 const char *bdrv_get_format_name(BlockDriverState *bs);
366 BlockDriverState *bdrv_find_node(const char *node_name);
367 BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp);
368 BlockDriverState *bdrv_lookup_bs(const char *device,
369                                  const char *node_name,
370                                  Error **errp);
371 bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
372 BlockDriverState *bdrv_next_node(BlockDriverState *bs);
373 
374 typedef struct BdrvNextIterator {
375     enum {
376         BDRV_NEXT_BACKEND_ROOTS,
377         BDRV_NEXT_MONITOR_OWNED,
378     } phase;
379     BlockBackend *blk;
380     BlockDriverState *bs;
381 } BdrvNextIterator;
382 
383 BlockDriverState *bdrv_first(BdrvNextIterator *it);
384 BlockDriverState *bdrv_next(BdrvNextIterator *it);
385 
386 BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
387 bool bdrv_is_encrypted(BlockDriverState *bs);
388 bool bdrv_key_required(BlockDriverState *bs);
389 int bdrv_set_key(BlockDriverState *bs, const char *key);
390 void bdrv_add_key(BlockDriverState *bs, const char *key, Error **errp);
391 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
392                          void *opaque);
393 const char *bdrv_get_node_name(const BlockDriverState *bs);
394 const char *bdrv_get_device_name(const BlockDriverState *bs);
395 const char *bdrv_get_device_or_node_name(const BlockDriverState *bs);
396 int bdrv_get_flags(BlockDriverState *bs);
397 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
398 ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs);
399 void bdrv_round_sectors_to_clusters(BlockDriverState *bs,
400                                     int64_t sector_num, int nb_sectors,
401                                     int64_t *cluster_sector_num,
402                                     int *cluster_nb_sectors);
403 void bdrv_round_to_clusters(BlockDriverState *bs,
404                             int64_t offset, unsigned int bytes,
405                             int64_t *cluster_offset,
406                             unsigned int *cluster_bytes);
407 
408 const char *bdrv_get_encrypted_filename(BlockDriverState *bs);
409 void bdrv_get_backing_filename(BlockDriverState *bs,
410                                char *filename, int filename_size);
411 void bdrv_get_full_backing_filename(BlockDriverState *bs,
412                                     char *dest, size_t sz, Error **errp);
413 void bdrv_get_full_backing_filename_from_filename(const char *backed,
414                                                   const char *backing,
415                                                   char *dest, size_t sz,
416                                                   Error **errp);
417 int bdrv_is_snapshot(BlockDriverState *bs);
418 
419 int path_has_protocol(const char *path);
420 int path_is_absolute(const char *path);
421 void path_combine(char *dest, int dest_size,
422                   const char *base_path,
423                   const char *filename);
424 
425 int bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
426 int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);
427 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
428                       int64_t pos, int size);
429 
430 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
431                       int64_t pos, int size);
432 
433 void bdrv_img_create(const char *filename, const char *fmt,
434                      const char *base_filename, const char *base_fmt,
435                      char *options, uint64_t img_size, int flags,
436                      Error **errp, bool quiet);
437 
438 /* Returns the alignment in bytes that is required so that no bounce buffer
439  * is required throughout the stack */
440 size_t bdrv_min_mem_align(BlockDriverState *bs);
441 /* Returns optimal alignment in bytes for bounce buffer */
442 size_t bdrv_opt_mem_align(BlockDriverState *bs);
443 void *qemu_blockalign(BlockDriverState *bs, size_t size);
444 void *qemu_blockalign0(BlockDriverState *bs, size_t size);
445 void *qemu_try_blockalign(BlockDriverState *bs, size_t size);
446 void *qemu_try_blockalign0(BlockDriverState *bs, size_t size);
447 bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov);
448 
449 void bdrv_enable_copy_on_read(BlockDriverState *bs);
450 void bdrv_disable_copy_on_read(BlockDriverState *bs);
451 
452 void bdrv_ref(BlockDriverState *bs);
453 void bdrv_unref(BlockDriverState *bs);
454 void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
455 BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
456                              BlockDriverState *child_bs,
457                              const char *child_name,
458                              const BdrvChildRole *child_role);
459 
460 bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
461 void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
462 void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
463 void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
464 void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
465 bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
466 
467 #define BLKDBG_EVENT(child, evt) \
468     do { \
469         if (child) { \
470             bdrv_debug_event(child->bs, evt); \
471         } \
472     } while (0)
473 
474 void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event);
475 
476 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
477                            const char *tag);
478 int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
479 int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
480 bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
481 
482 /**
483  * bdrv_get_aio_context:
484  *
485  * Returns: the currently bound #AioContext
486  */
487 AioContext *bdrv_get_aio_context(BlockDriverState *bs);
488 
489 /**
490  * bdrv_set_aio_context:
491  *
492  * Changes the #AioContext used for fd handlers, timers, and BHs by this
493  * BlockDriverState and all its children.
494  *
495  * This function must be called with iothread lock held.
496  */
497 void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context);
498 int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
499 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
500 
501 void bdrv_io_plug(BlockDriverState *bs);
502 void bdrv_io_unplug(BlockDriverState *bs);
503 void bdrv_io_unplugged_begin(BlockDriverState *bs);
504 void bdrv_io_unplugged_end(BlockDriverState *bs);
505 
506 /**
507  * bdrv_drained_begin:
508  *
509  * Begin a quiesced section for exclusive access to the BDS, by disabling
510  * external request sources including NBD server and device model. Note that
511  * this doesn't block timers or coroutines from submitting more requests, which
512  * means block_job_pause is still necessary.
513  *
514  * This function can be recursive.
515  */
516 void bdrv_drained_begin(BlockDriverState *bs);
517 
518 /**
519  * bdrv_drained_end:
520  *
521  * End a quiescent section started by bdrv_drained_begin().
522  */
523 void bdrv_drained_end(BlockDriverState *bs);
524 
525 void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child,
526                     Error **errp);
527 void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
528 
529 #endif
530