block: Add error handling to bdrv_invalidate_cache()
[qemu.git] / include / block / block_int.h
1 /*
2 * QEMU System Emulator block driver
3 *
4 * Copyright (c) 2003 Fabrice Bellard
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24 #ifndef BLOCK_INT_H
25 #define BLOCK_INT_H
26
27 #include "block/block.h"
28 #include "qemu/option.h"
29 #include "qemu/queue.h"
30 #include "block/coroutine.h"
31 #include "qemu/timer.h"
32 #include "qapi-types.h"
33 #include "qapi/qmp/qerror.h"
34 #include "monitor/monitor.h"
35 #include "qemu/hbitmap.h"
36 #include "block/snapshot.h"
37 #include "qemu/main-loop.h"
38 #include "qemu/throttle.h"
39
40 #define BLOCK_FLAG_ENCRYPT 1
41 #define BLOCK_FLAG_COMPAT6 4
42 #define BLOCK_FLAG_LAZY_REFCOUNTS 8
43
44 #define BLOCK_OPT_SIZE "size"
45 #define BLOCK_OPT_ENCRYPT "encryption"
46 #define BLOCK_OPT_COMPAT6 "compat6"
47 #define BLOCK_OPT_BACKING_FILE "backing_file"
48 #define BLOCK_OPT_BACKING_FMT "backing_fmt"
49 #define BLOCK_OPT_CLUSTER_SIZE "cluster_size"
50 #define BLOCK_OPT_TABLE_SIZE "table_size"
51 #define BLOCK_OPT_PREALLOC "preallocation"
52 #define BLOCK_OPT_SUBFMT "subformat"
53 #define BLOCK_OPT_COMPAT_LEVEL "compat"
54 #define BLOCK_OPT_LAZY_REFCOUNTS "lazy_refcounts"
55 #define BLOCK_OPT_ADAPTER_TYPE "adapter_type"
56 #define BLOCK_OPT_REDUNDANCY "redundancy"
57
58 typedef struct BdrvTrackedRequest {
59 BlockDriverState *bs;
60 int64_t offset;
61 unsigned int bytes;
62 bool is_write;
63
64 bool serialising;
65 int64_t overlap_offset;
66 unsigned int overlap_bytes;
67
68 QLIST_ENTRY(BdrvTrackedRequest) list;
69 Coroutine *co; /* owner, used for deadlock detection */
70 CoQueue wait_queue; /* coroutines blocked on this request */
71
72 struct BdrvTrackedRequest *waiting_for;
73 } BdrvTrackedRequest;
74
75 struct BlockDriver {
76 const char *format_name;
77 int instance_size;
78
79 /* set to true if the BlockDriver is a block filter */
80 bool is_filter;
81 /* for snapshots block filter like Quorum can implement the
82 * following recursive callback.
83 * It's purpose is to recurse on the filter children while calling
84 * bdrv_recurse_is_first_non_filter on them.
85 * For a sample implementation look in the future Quorum block filter.
86 */
87 bool (*bdrv_recurse_is_first_non_filter)(BlockDriverState *bs,
88 BlockDriverState *candidate);
89
90 int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
91 int (*bdrv_probe_device)(const char *filename);
92
93 /* Any driver implementing this callback is expected to be able to handle
94 * NULL file names in its .bdrv_open() implementation */
95 void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp);
96 /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have
97 * this field set to true, except ones that are defined only by their
98 * child's bs.
99 * An example of the last type will be the quorum block driver.
100 */
101 bool bdrv_needs_filename;
102
103 /* For handling image reopen for split or non-split files */
104 int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,
105 BlockReopenQueue *queue, Error **errp);
106 void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);
107 void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state);
108
109 int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags,
110 Error **errp);
111 int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags,
112 Error **errp);
113 int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
114 uint8_t *buf, int nb_sectors);
115 int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
116 const uint8_t *buf, int nb_sectors);
117 void (*bdrv_close)(BlockDriverState *bs);
118 void (*bdrv_rebind)(BlockDriverState *bs);
119 int (*bdrv_create)(const char *filename, QEMUOptionParameter *options,
120 Error **errp);
121 int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
122 int (*bdrv_make_empty)(BlockDriverState *bs);
123 /* aio */
124 BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
125 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
126 BlockDriverCompletionFunc *cb, void *opaque);
127 BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
128 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
129 BlockDriverCompletionFunc *cb, void *opaque);
130 BlockDriverAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
131 BlockDriverCompletionFunc *cb, void *opaque);
132 BlockDriverAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs,
133 int64_t sector_num, int nb_sectors,
134 BlockDriverCompletionFunc *cb, void *opaque);
135
136 int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
137 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
138 int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
139 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
140 /*
141 * Efficiently zero a region of the disk image. Typically an image format
142 * would use a compact metadata representation to implement this. This
143 * function pointer may be NULL and .bdrv_co_writev() will be called
144 * instead.
145 */
146 int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs,
147 int64_t sector_num, int nb_sectors, BdrvRequestFlags flags);
148 int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
149 int64_t sector_num, int nb_sectors);
150 int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs,
151 int64_t sector_num, int nb_sectors, int *pnum);
152
153 /*
154 * Invalidate any cached meta-data.
155 */
156 void (*bdrv_invalidate_cache)(BlockDriverState *bs, Error **errp);
157
158 /*
159 * Flushes all data that was already written to the OS all the way down to
160 * the disk (for example raw-posix calls fsync()).
161 */
162 int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
163
164 /*
165 * Flushes all internal caches to the OS. The data may still sit in a
166 * writeback cache of the host OS, but it will survive a crash of the qemu
167 * process.
168 */
169 int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
170
171 const char *protocol_name;
172 int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
173
174 int64_t (*bdrv_getlength)(BlockDriverState *bs);
175 bool has_variable_length;
176 int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
177
178 int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
179 const uint8_t *buf, int nb_sectors);
180
181 int (*bdrv_snapshot_create)(BlockDriverState *bs,
182 QEMUSnapshotInfo *sn_info);
183 int (*bdrv_snapshot_goto)(BlockDriverState *bs,
184 const char *snapshot_id);
185 int (*bdrv_snapshot_delete)(BlockDriverState *bs,
186 const char *snapshot_id,
187 const char *name,
188 Error **errp);
189 int (*bdrv_snapshot_list)(BlockDriverState *bs,
190 QEMUSnapshotInfo **psn_info);
191 int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
192 const char *snapshot_id,
193 const char *name,
194 Error **errp);
195 int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
196 ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs);
197
198 int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov,
199 int64_t pos);
200 int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
201 int64_t pos, int size);
202
203 int (*bdrv_change_backing_file)(BlockDriverState *bs,
204 const char *backing_file, const char *backing_fmt);
205
206 /* removable device specific */
207 int (*bdrv_is_inserted)(BlockDriverState *bs);
208 int (*bdrv_media_changed)(BlockDriverState *bs);
209 void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
210 void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
211
212 /* to control generic scsi devices */
213 int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf);
214 BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
215 unsigned long int req, void *buf,
216 BlockDriverCompletionFunc *cb, void *opaque);
217
218 /* List of options for creating images, terminated by name == NULL */
219 QEMUOptionParameter *create_options;
220
221
222 /*
223 * Returns 0 for completed check, -errno for internal errors.
224 * The check results are stored in result.
225 */
226 int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result,
227 BdrvCheckMode fix);
228
229 int (*bdrv_amend_options)(BlockDriverState *bs,
230 QEMUOptionParameter *options);
231
232 void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event);
233
234 /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
235 int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
236 const char *tag);
237 int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs,
238 const char *tag);
239 int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);
240 bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);
241
242 int (*bdrv_refresh_limits)(BlockDriverState *bs);
243
244 /*
245 * Returns 1 if newly created images are guaranteed to contain only
246 * zeros, 0 otherwise.
247 */
248 int (*bdrv_has_zero_init)(BlockDriverState *bs);
249
250 QLIST_ENTRY(BlockDriver) list;
251 };
252
253 typedef struct BlockLimits {
254 /* maximum number of sectors that can be discarded at once */
255 int max_discard;
256
257 /* optimal alignment for discard requests in sectors */
258 int64_t discard_alignment;
259
260 /* maximum number of sectors that can zeroized at once */
261 int max_write_zeroes;
262
263 /* optimal alignment for write zeroes requests in sectors */
264 int64_t write_zeroes_alignment;
265
266 /* optimal transfer length in sectors */
267 int opt_transfer_length;
268
269 /* memory alignment so that no bounce buffer is needed */
270 size_t opt_mem_alignment;
271 } BlockLimits;
272
273 /*
274 * Note: the function bdrv_append() copies and swaps contents of
275 * BlockDriverStates, so if you add new fields to this struct, please
276 * inspect bdrv_append() to determine if the new fields need to be
277 * copied as well.
278 */
279 struct BlockDriverState {
280 int64_t total_sectors; /* if we are reading a disk image, give its
281 size in sectors */
282 int read_only; /* if true, the media is read only */
283 int open_flags; /* flags used to open the file, re-used for re-open */
284 int encrypted; /* if true, the media is encrypted */
285 int valid_key; /* if true, a valid encryption key has been set */
286 int sg; /* if true, the device is a /dev/sg* */
287 int copy_on_read; /* if true, copy read backing sectors into image
288 note this is a reference count */
289
290 BlockDriver *drv; /* NULL means no media */
291 void *opaque;
292
293 void *dev; /* attached device model, if any */
294 /* TODO change to DeviceState when all users are qdevified */
295 const BlockDevOps *dev_ops;
296 void *dev_opaque;
297
298 char filename[1024];
299 char backing_file[1024]; /* if non zero, the image is a diff of
300 this file image */
301 char backing_format[16]; /* if non-zero and backing_file exists */
302 int is_temporary;
303
304 BlockDriverState *backing_hd;
305 BlockDriverState *file;
306
307 NotifierList close_notifiers;
308
309 /* Callback before write request is processed */
310 NotifierWithReturnList before_write_notifiers;
311
312 /* number of in-flight serialising requests */
313 unsigned int serialising_in_flight;
314
315 /* I/O throttling */
316 ThrottleState throttle_state;
317 CoQueue throttled_reqs[2];
318 bool io_limits_enabled;
319
320 /* I/O stats (display with "info blockstats"). */
321 uint64_t nr_bytes[BDRV_MAX_IOTYPE];
322 uint64_t nr_ops[BDRV_MAX_IOTYPE];
323 uint64_t total_time_ns[BDRV_MAX_IOTYPE];
324 uint64_t wr_highest_sector;
325
326 /* I/O Limits */
327 BlockLimits bl;
328
329 /* Whether the disk can expand beyond total_sectors */
330 int growable;
331
332 /* Whether produces zeros when read beyond eof */
333 bool zero_beyond_eof;
334
335 /* Alignment requirement for offset/length of I/O requests */
336 unsigned int request_alignment;
337
338 /* the block size for which the guest device expects atomicity */
339 int guest_block_size;
340
341 /* do we need to tell the quest if we have a volatile write cache? */
342 int enable_write_cache;
343
344 /* NOTE: the following infos are only hints for real hardware
345 drivers. They are not used by the block driver */
346 BlockdevOnError on_read_error, on_write_error;
347 bool iostatus_enabled;
348 BlockDeviceIoStatus iostatus;
349
350 /* the following member gives a name to every node on the bs graph. */
351 char node_name[32];
352 /* element of the list of named nodes building the graph */
353 QTAILQ_ENTRY(BlockDriverState) node_list;
354 /* Device name is the name associated with the "drive" the guest sees */
355 char device_name[32];
356 /* element of the list of "drives" the guest sees */
357 QTAILQ_ENTRY(BlockDriverState) device_list;
358 QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
359 int refcnt;
360 int in_use; /* users other than guest access, eg. block migration */
361
362 QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
363
364 /* long-running background operation */
365 BlockJob *job;
366
367 QDict *options;
368 };
369
370 int get_tmp_filename(char *filename, int size);
371
372 void bdrv_set_io_limits(BlockDriverState *bs,
373 ThrottleConfig *cfg);
374
375
376 /**
377 * bdrv_add_before_write_notifier:
378 *
379 * Register a callback that is invoked before write requests are processed but
380 * after any throttling or waiting for overlapping requests.
381 */
382 void bdrv_add_before_write_notifier(BlockDriverState *bs,
383 NotifierWithReturn *notifier);
384
385 /**
386 * bdrv_get_aio_context:
387 *
388 * Returns: the currently bound #AioContext
389 */
390 AioContext *bdrv_get_aio_context(BlockDriverState *bs);
391
392 #ifdef _WIN32
393 int is_windows_drive(const char *filename);
394 #endif
395 void bdrv_emit_qmp_error_event(const BlockDriverState *bdrv,
396 enum MonitorEvent ev,
397 BlockErrorAction action, bool is_read);
398
399 /**
400 * stream_start:
401 * @bs: Block device to operate on.
402 * @base: Block device that will become the new base, or %NULL to
403 * flatten the whole backing file chain onto @bs.
404 * @base_id: The file name that will be written to @bs as the new
405 * backing file if the job completes. Ignored if @base is %NULL.
406 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
407 * @on_error: The action to take upon error.
408 * @cb: Completion function for the job.
409 * @opaque: Opaque pointer value passed to @cb.
410 * @errp: Error object.
411 *
412 * Start a streaming operation on @bs. Clusters that are unallocated
413 * in @bs, but allocated in any image between @base and @bs (both
414 * exclusive) will be written to @bs. At the end of a successful
415 * streaming job, the backing file of @bs will be changed to
416 * @base_id in the written image and to @base in the live BlockDriverState.
417 */
418 void stream_start(BlockDriverState *bs, BlockDriverState *base,
419 const char *base_id, int64_t speed, BlockdevOnError on_error,
420 BlockDriverCompletionFunc *cb,
421 void *opaque, Error **errp);
422
423 /**
424 * commit_start:
425 * @bs: Active block device.
426 * @top: Top block device to be committed.
427 * @base: Block device that will be written into, and become the new top.
428 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
429 * @on_error: The action to take upon error.
430 * @cb: Completion function for the job.
431 * @opaque: Opaque pointer value passed to @cb.
432 * @errp: Error object.
433 *
434 */
435 void commit_start(BlockDriverState *bs, BlockDriverState *base,
436 BlockDriverState *top, int64_t speed,
437 BlockdevOnError on_error, BlockDriverCompletionFunc *cb,
438 void *opaque, Error **errp);
439 /**
440 * commit_active_start:
441 * @bs: Active block device to be committed.
442 * @base: Block device that will be written into, and become the new top.
443 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
444 * @on_error: The action to take upon error.
445 * @cb: Completion function for the job.
446 * @opaque: Opaque pointer value passed to @cb.
447 * @errp: Error object.
448 *
449 */
450 void commit_active_start(BlockDriverState *bs, BlockDriverState *base,
451 int64_t speed,
452 BlockdevOnError on_error,
453 BlockDriverCompletionFunc *cb,
454 void *opaque, Error **errp);
455 /*
456 * mirror_start:
457 * @bs: Block device to operate on.
458 * @target: Block device to write to.
459 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
460 * @granularity: The chosen granularity for the dirty bitmap.
461 * @buf_size: The amount of data that can be in flight at one time.
462 * @mode: Whether to collapse all images in the chain to the target.
463 * @on_source_error: The action to take upon error reading from the source.
464 * @on_target_error: The action to take upon error writing to the target.
465 * @cb: Completion function for the job.
466 * @opaque: Opaque pointer value passed to @cb.
467 * @errp: Error object.
468 *
469 * Start a mirroring operation on @bs. Clusters that are allocated
470 * in @bs will be written to @bs until the job is cancelled or
471 * manually completed. At the end of a successful mirroring job,
472 * @bs will be switched to read from @target.
473 */
474 void mirror_start(BlockDriverState *bs, BlockDriverState *target,
475 int64_t speed, int64_t granularity, int64_t buf_size,
476 MirrorSyncMode mode, BlockdevOnError on_source_error,
477 BlockdevOnError on_target_error,
478 BlockDriverCompletionFunc *cb,
479 void *opaque, Error **errp);
480
481 /*
482 * backup_start:
483 * @bs: Block device to operate on.
484 * @target: Block device to write to.
485 * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
486 * @sync_mode: What parts of the disk image should be copied to the destination.
487 * @on_source_error: The action to take upon error reading from the source.
488 * @on_target_error: The action to take upon error writing to the target.
489 * @cb: Completion function for the job.
490 * @opaque: Opaque pointer value passed to @cb.
491 *
492 * Start a backup operation on @bs. Clusters in @bs are written to @target
493 * until the job is cancelled or manually completed.
494 */
495 void backup_start(BlockDriverState *bs, BlockDriverState *target,
496 int64_t speed, MirrorSyncMode sync_mode,
497 BlockdevOnError on_source_error,
498 BlockdevOnError on_target_error,
499 BlockDriverCompletionFunc *cb, void *opaque,
500 Error **errp);
501
502 #endif /* BLOCK_INT_H */