xref: /openbmc/qemu/include/block/block.h (revision 32bafa8f)
1 #ifndef BLOCK_H
2 #define BLOCK_H
3 
4 #include "block/aio.h"
5 #include "qemu-common.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 } BdrvRequestFlags;
68 
69 typedef struct BlockSizes {
70     uint32_t phys;
71     uint32_t log;
72 } BlockSizes;
73 
74 typedef struct HDGeometry {
75     uint32_t heads;
76     uint32_t sectors;
77     uint32_t cylinders;
78 } HDGeometry;
79 
80 #define BDRV_O_RDWR        0x0002
81 #define BDRV_O_SNAPSHOT    0x0008 /* open the file read only and save writes in a snapshot */
82 #define BDRV_O_TEMPORARY   0x0010 /* delete the file after use */
83 #define BDRV_O_NOCACHE     0x0020 /* do not use the host page cache */
84 #define BDRV_O_CACHE_WB    0x0040 /* use write-back caching */
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 
97 #define BDRV_O_CACHE_MASK  (BDRV_O_NOCACHE | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH)
98 
99 
100 /* Option names of options parsed by the block layer */
101 
102 #define BDRV_OPT_CACHE_WB       "cache.writeback"
103 #define BDRV_OPT_CACHE_DIRECT   "cache.direct"
104 #define BDRV_OPT_CACHE_NO_FLUSH "cache.no-flush"
105 
106 
107 #define BDRV_SECTOR_BITS   9
108 #define BDRV_SECTOR_SIZE   (1ULL << BDRV_SECTOR_BITS)
109 #define BDRV_SECTOR_MASK   ~(BDRV_SECTOR_SIZE - 1)
110 
111 #define BDRV_REQUEST_MAX_SECTORS MIN(SIZE_MAX >> BDRV_SECTOR_BITS, \
112                                      INT_MAX >> BDRV_SECTOR_BITS)
113 
114 /*
115  * Allocation status flags
116  * BDRV_BLOCK_DATA: data is read from a file returned by bdrv_get_block_status.
117  * BDRV_BLOCK_ZERO: sectors read as zero
118  * BDRV_BLOCK_OFFSET_VALID: sector stored as raw data in a file returned by
119  *                          bdrv_get_block_status.
120  * BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
121  *                       layer (as opposed to the backing file)
122  * BDRV_BLOCK_RAW: used internally to indicate that the request
123  *                 was answered by the raw driver and that one
124  *                 should look in bs->file directly.
125  *
126  * If BDRV_BLOCK_OFFSET_VALID is set, bits 9-62 represent the offset in
127  * bs->file where sector data can be read from as raw data.
128  *
129  * DATA == 0 && ZERO == 0 means that data is read from backing_hd if present.
130  *
131  * DATA ZERO OFFSET_VALID
132  *  t    t        t       sectors read as zero, bs->file is zero at offset
133  *  t    f        t       sectors read as valid from bs->file at offset
134  *  f    t        t       sectors preallocated, read as zero, bs->file not
135  *                        necessarily zero at offset
136  *  f    f        t       sectors preallocated but read from backing_hd,
137  *                        bs->file contains garbage at offset
138  *  t    t        f       sectors preallocated, read as zero, unknown offset
139  *  t    f        f       sectors read from unknown file or offset
140  *  f    t        f       not allocated or unknown offset, read as zero
141  *  f    f        f       not allocated or unknown offset, read from backing_hd
142  */
143 #define BDRV_BLOCK_DATA         0x01
144 #define BDRV_BLOCK_ZERO         0x02
145 #define BDRV_BLOCK_OFFSET_VALID 0x04
146 #define BDRV_BLOCK_RAW          0x08
147 #define BDRV_BLOCK_ALLOCATED    0x10
148 #define BDRV_BLOCK_OFFSET_MASK  BDRV_SECTOR_MASK
149 
150 typedef QSIMPLEQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue;
151 
152 typedef struct BDRVReopenState {
153     BlockDriverState *bs;
154     int flags;
155     QDict *options;
156     QDict *explicit_options;
157     void *opaque;
158 } BDRVReopenState;
159 
160 /*
161  * Block operation types
162  */
163 typedef enum BlockOpType {
164     BLOCK_OP_TYPE_BACKUP_SOURCE,
165     BLOCK_OP_TYPE_BACKUP_TARGET,
166     BLOCK_OP_TYPE_CHANGE,
167     BLOCK_OP_TYPE_COMMIT_SOURCE,
168     BLOCK_OP_TYPE_COMMIT_TARGET,
169     BLOCK_OP_TYPE_DATAPLANE,
170     BLOCK_OP_TYPE_DRIVE_DEL,
171     BLOCK_OP_TYPE_EJECT,
172     BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,
173     BLOCK_OP_TYPE_INTERNAL_SNAPSHOT,
174     BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
175     BLOCK_OP_TYPE_MIRROR_SOURCE,
176     BLOCK_OP_TYPE_MIRROR_TARGET,
177     BLOCK_OP_TYPE_RESIZE,
178     BLOCK_OP_TYPE_STREAM,
179     BLOCK_OP_TYPE_REPLACE,
180     BLOCK_OP_TYPE_MAX,
181 } BlockOpType;
182 
183 void bdrv_info_print(Monitor *mon, const QObject *data);
184 void bdrv_info(Monitor *mon, QObject **ret_data);
185 void bdrv_stats_print(Monitor *mon, const QObject *data);
186 void bdrv_info_stats(Monitor *mon, QObject **ret_data);
187 
188 /* disk I/O throttling */
189 void bdrv_io_limits_enable(BlockDriverState *bs, const char *group);
190 void bdrv_io_limits_disable(BlockDriverState *bs);
191 void bdrv_io_limits_update_group(BlockDriverState *bs, const char *group);
192 
193 void bdrv_init(void);
194 void bdrv_init_with_whitelist(void);
195 BlockDriver *bdrv_find_protocol(const char *filename,
196                                 bool allow_protocol_prefix,
197                                 Error **errp);
198 BlockDriver *bdrv_find_format(const char *format_name);
199 int bdrv_create(BlockDriver *drv, const char* filename,
200                 QemuOpts *opts, Error **errp);
201 int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp);
202 BlockDriverState *bdrv_new_root(void);
203 BlockDriverState *bdrv_new(void);
204 void bdrv_make_anon(BlockDriverState *bs);
205 void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top);
206 void bdrv_replace_in_backing_chain(BlockDriverState *old,
207                                    BlockDriverState *new);
208 
209 int bdrv_parse_cache_flags(const char *mode, int *flags);
210 int bdrv_parse_discard_flags(const char *mode, int *flags);
211 BdrvChild *bdrv_open_child(const char *filename,
212                            QDict *options, const char *bdref_key,
213                            BlockDriverState* parent,
214                            const BdrvChildRole *child_role,
215                            bool allow_none, Error **errp);
216 void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd);
217 int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
218                            const char *bdref_key, Error **errp);
219 int bdrv_open(BlockDriverState **pbs, const char *filename,
220               const char *reference, QDict *options, int flags, Error **errp);
221 BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
222                                     BlockDriverState *bs,
223                                     QDict *options, int flags);
224 int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp);
225 int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp);
226 int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
227                         BlockReopenQueue *queue, Error **errp);
228 void bdrv_reopen_commit(BDRVReopenState *reopen_state);
229 void bdrv_reopen_abort(BDRVReopenState *reopen_state);
230 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
231               uint8_t *buf, int nb_sectors);
232 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
233                const uint8_t *buf, int nb_sectors);
234 int bdrv_write_zeroes(BlockDriverState *bs, int64_t sector_num,
235                int nb_sectors, BdrvRequestFlags flags);
236 BlockAIOCB *bdrv_aio_write_zeroes(BlockDriverState *bs, int64_t sector_num,
237                                   int nb_sectors, BdrvRequestFlags flags,
238                                   BlockCompletionFunc *cb, void *opaque);
239 int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags);
240 int bdrv_pread(BlockDriverState *bs, int64_t offset,
241                void *buf, int count);
242 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
243                 const void *buf, int count);
244 int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov);
245 int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
246     const void *buf, int count);
247 int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
248     int nb_sectors, QEMUIOVector *qiov);
249 int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs,
250     int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
251 int coroutine_fn bdrv_co_readv_no_serialising(BlockDriverState *bs,
252     int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
253 int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
254     int nb_sectors, QEMUIOVector *qiov);
255 /*
256  * Efficiently zero a region of the disk image.  Note that this is a regular
257  * I/O request like read or write and should have a reasonable size.  This
258  * function is not suitable for zeroing the entire image in a single request
259  * because it may allocate memory for the entire region.
260  */
261 int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs, int64_t sector_num,
262     int nb_sectors, BdrvRequestFlags flags);
263 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
264     const char *backing_file);
265 int bdrv_get_backing_file_depth(BlockDriverState *bs);
266 void bdrv_refresh_filename(BlockDriverState *bs);
267 int bdrv_truncate(BlockDriverState *bs, int64_t offset);
268 int64_t bdrv_nb_sectors(BlockDriverState *bs);
269 int64_t bdrv_getlength(BlockDriverState *bs);
270 int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);
271 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
272 void bdrv_refresh_limits(BlockDriverState *bs, Error **errp);
273 int bdrv_commit(BlockDriverState *bs);
274 int bdrv_change_backing_file(BlockDriverState *bs,
275     const char *backing_file, const char *backing_fmt);
276 void bdrv_register(BlockDriver *bdrv);
277 int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
278                            BlockDriverState *base,
279                            const char *backing_file_str);
280 BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
281                                     BlockDriverState *bs);
282 BlockDriverState *bdrv_find_base(BlockDriverState *bs);
283 
284 
285 typedef struct BdrvCheckResult {
286     int corruptions;
287     int leaks;
288     int check_errors;
289     int corruptions_fixed;
290     int leaks_fixed;
291     int64_t image_end_offset;
292     BlockFragInfo bfi;
293 } BdrvCheckResult;
294 
295 typedef enum {
296     BDRV_FIX_LEAKS    = 1,
297     BDRV_FIX_ERRORS   = 2,
298 } BdrvCheckMode;
299 
300 int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix);
301 
302 /* The units of offset and total_work_size may be chosen arbitrarily by the
303  * block driver; total_work_size may change during the course of the amendment
304  * operation */
305 typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
306                                       int64_t total_work_size, void *opaque);
307 int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
308                        BlockDriverAmendStatusCB *status_cb, void *cb_opaque);
309 
310 /* external snapshots */
311 bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
312                                       BlockDriverState *candidate);
313 bool bdrv_is_first_non_filter(BlockDriverState *candidate);
314 
315 /* check if a named node can be replaced when doing drive-mirror */
316 BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
317                                         const char *node_name, Error **errp);
318 
319 /* async block I/O */
320 BlockAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
321                            QEMUIOVector *iov, int nb_sectors,
322                            BlockCompletionFunc *cb, void *opaque);
323 BlockAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
324                             QEMUIOVector *iov, int nb_sectors,
325                             BlockCompletionFunc *cb, void *opaque);
326 BlockAIOCB *bdrv_aio_flush(BlockDriverState *bs,
327                            BlockCompletionFunc *cb, void *opaque);
328 BlockAIOCB *bdrv_aio_discard(BlockDriverState *bs,
329                              int64_t sector_num, int nb_sectors,
330                              BlockCompletionFunc *cb, void *opaque);
331 void bdrv_aio_cancel(BlockAIOCB *acb);
332 void bdrv_aio_cancel_async(BlockAIOCB *acb);
333 
334 typedef struct BlockRequest {
335     /* Fields to be filled by multiwrite caller */
336     union {
337         struct {
338             int64_t sector;
339             int nb_sectors;
340             int flags;
341             QEMUIOVector *qiov;
342         };
343         struct {
344             int req;
345             void *buf;
346         };
347     };
348     BlockCompletionFunc *cb;
349     void *opaque;
350 
351     /* Filled by multiwrite implementation */
352     int error;
353 } BlockRequest;
354 
355 int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs,
356     int num_reqs);
357 
358 /* sg packet commands */
359 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf);
360 BlockAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
361         unsigned long int req, void *buf,
362         BlockCompletionFunc *cb, void *opaque);
363 
364 /* Invalidate any cached metadata used by image formats */
365 void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp);
366 void bdrv_invalidate_cache_all(Error **errp);
367 int bdrv_inactivate_all(void);
368 
369 /* Ensure contents are flushed to disk.  */
370 int bdrv_flush(BlockDriverState *bs);
371 int coroutine_fn bdrv_co_flush(BlockDriverState *bs);
372 void bdrv_close_all(void);
373 void bdrv_drain(BlockDriverState *bs);
374 void bdrv_drain_all(void);
375 
376 int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
377 int bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
378 int bdrv_has_zero_init_1(BlockDriverState *bs);
379 int bdrv_has_zero_init(BlockDriverState *bs);
380 bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs);
381 bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
382 int64_t bdrv_get_block_status(BlockDriverState *bs, int64_t sector_num,
383                               int nb_sectors, int *pnum,
384                               BlockDriverState **file);
385 int64_t bdrv_get_block_status_above(BlockDriverState *bs,
386                                     BlockDriverState *base,
387                                     int64_t sector_num,
388                                     int nb_sectors, int *pnum,
389                                     BlockDriverState **file);
390 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
391                       int *pnum);
392 int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base,
393                             int64_t sector_num, int nb_sectors, int *pnum);
394 
395 int bdrv_is_read_only(BlockDriverState *bs);
396 int bdrv_is_sg(BlockDriverState *bs);
397 int bdrv_enable_write_cache(BlockDriverState *bs);
398 void bdrv_set_enable_write_cache(BlockDriverState *bs, bool wce);
399 bool bdrv_is_inserted(BlockDriverState *bs);
400 int bdrv_media_changed(BlockDriverState *bs);
401 void bdrv_lock_medium(BlockDriverState *bs, bool locked);
402 void bdrv_eject(BlockDriverState *bs, bool eject_flag);
403 const char *bdrv_get_format_name(BlockDriverState *bs);
404 BlockDriverState *bdrv_find_node(const char *node_name);
405 BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp);
406 BlockDriverState *bdrv_lookup_bs(const char *device,
407                                  const char *node_name,
408                                  Error **errp);
409 bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
410 BlockDriverState *bdrv_next_node(BlockDriverState *bs);
411 BlockDriverState *bdrv_next(BlockDriverState *bs);
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 
480 bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
481 void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
482 void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
483 void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
484 void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
485 bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
486 
487 #define BLKDBG_EVENT(child, evt) \
488     do { \
489         if (child) { \
490             bdrv_debug_event(child->bs, evt); \
491         } \
492     } while (0)
493 
494 void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event);
495 
496 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
497                            const char *tag);
498 int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
499 int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
500 bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
501 
502 /**
503  * bdrv_get_aio_context:
504  *
505  * Returns: the currently bound #AioContext
506  */
507 AioContext *bdrv_get_aio_context(BlockDriverState *bs);
508 
509 /**
510  * bdrv_set_aio_context:
511  *
512  * Changes the #AioContext used for fd handlers, timers, and BHs by this
513  * BlockDriverState and all its children.
514  *
515  * This function must be called with iothread lock held.
516  */
517 void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context);
518 int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
519 int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
520 
521 void bdrv_io_plug(BlockDriverState *bs);
522 void bdrv_io_unplug(BlockDriverState *bs);
523 void bdrv_flush_io_queue(BlockDriverState *bs);
524 
525 /**
526  * bdrv_drained_begin:
527  *
528  * Begin a quiesced section for exclusive access to the BDS, by disabling
529  * external request sources including NBD server and device model. Note that
530  * this doesn't block timers or coroutines from submitting more requests, which
531  * means block_job_pause is still necessary.
532  *
533  * This function can be recursive.
534  */
535 void bdrv_drained_begin(BlockDriverState *bs);
536 
537 /**
538  * bdrv_drained_end:
539  *
540  * End a quiescent section started by bdrv_drained_begin().
541  */
542 void bdrv_drained_end(BlockDriverState *bs);
543 
544 #endif
545