xref: /openbmc/qemu/include/block/block_int.h (revision 2d7fedeb)
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/accounting.h"
28 #include "block/block.h"
29 #include "qemu/option.h"
30 #include "qemu/queue.h"
31 #include "qemu/coroutine.h"
32 #include "qemu/timer.h"
33 #include "qapi-types.h"
34 #include "qemu/hbitmap.h"
35 #include "block/snapshot.h"
36 #include "qemu/main-loop.h"
37 #include "qemu/throttle.h"
38 
39 #define BLOCK_FLAG_ENCRYPT          1
40 #define BLOCK_FLAG_LAZY_REFCOUNTS   8
41 
42 #define BLOCK_OPT_SIZE              "size"
43 #define BLOCK_OPT_ENCRYPT           "encryption"
44 #define BLOCK_OPT_COMPAT6           "compat6"
45 #define BLOCK_OPT_HWVERSION         "hwversion"
46 #define BLOCK_OPT_BACKING_FILE      "backing_file"
47 #define BLOCK_OPT_BACKING_FMT       "backing_fmt"
48 #define BLOCK_OPT_CLUSTER_SIZE      "cluster_size"
49 #define BLOCK_OPT_TABLE_SIZE        "table_size"
50 #define BLOCK_OPT_PREALLOC          "preallocation"
51 #define BLOCK_OPT_SUBFMT            "subformat"
52 #define BLOCK_OPT_COMPAT_LEVEL      "compat"
53 #define BLOCK_OPT_LAZY_REFCOUNTS    "lazy_refcounts"
54 #define BLOCK_OPT_ADAPTER_TYPE      "adapter_type"
55 #define BLOCK_OPT_REDUNDANCY        "redundancy"
56 #define BLOCK_OPT_NOCOW             "nocow"
57 #define BLOCK_OPT_OBJECT_SIZE       "object_size"
58 #define BLOCK_OPT_REFCOUNT_BITS     "refcount_bits"
59 
60 #define BLOCK_PROBE_BUF_SIZE        512
61 
62 enum BdrvTrackedRequestType {
63     BDRV_TRACKED_READ,
64     BDRV_TRACKED_WRITE,
65     BDRV_TRACKED_FLUSH,
66     BDRV_TRACKED_IOCTL,
67     BDRV_TRACKED_DISCARD,
68 };
69 
70 typedef struct BdrvTrackedRequest {
71     BlockDriverState *bs;
72     int64_t offset;
73     unsigned int bytes;
74     enum BdrvTrackedRequestType type;
75 
76     bool serialising;
77     int64_t overlap_offset;
78     unsigned int overlap_bytes;
79 
80     QLIST_ENTRY(BdrvTrackedRequest) list;
81     Coroutine *co; /* owner, used for deadlock detection */
82     CoQueue wait_queue; /* coroutines blocked on this request */
83 
84     struct BdrvTrackedRequest *waiting_for;
85 } BdrvTrackedRequest;
86 
87 struct BlockDriver {
88     const char *format_name;
89     int instance_size;
90 
91     /* set to true if the BlockDriver is a block filter */
92     bool is_filter;
93     /* for snapshots block filter like Quorum can implement the
94      * following recursive callback.
95      * It's purpose is to recurse on the filter children while calling
96      * bdrv_recurse_is_first_non_filter on them.
97      * For a sample implementation look in the future Quorum block filter.
98      */
99     bool (*bdrv_recurse_is_first_non_filter)(BlockDriverState *bs,
100                                              BlockDriverState *candidate);
101 
102     int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
103     int (*bdrv_probe_device)(const char *filename);
104 
105     /* Any driver implementing this callback is expected to be able to handle
106      * NULL file names in its .bdrv_open() implementation */
107     void (*bdrv_parse_filename)(const char *filename, QDict *options, Error **errp);
108     /* Drivers not implementing bdrv_parse_filename nor bdrv_open should have
109      * this field set to true, except ones that are defined only by their
110      * child's bs.
111      * An example of the last type will be the quorum block driver.
112      */
113     bool bdrv_needs_filename;
114 
115     /* Set if a driver can support backing files */
116     bool supports_backing;
117 
118     /* For handling image reopen for split or non-split files */
119     int (*bdrv_reopen_prepare)(BDRVReopenState *reopen_state,
120                                BlockReopenQueue *queue, Error **errp);
121     void (*bdrv_reopen_commit)(BDRVReopenState *reopen_state);
122     void (*bdrv_reopen_abort)(BDRVReopenState *reopen_state);
123     void (*bdrv_join_options)(QDict *options, QDict *old_options);
124 
125     int (*bdrv_open)(BlockDriverState *bs, QDict *options, int flags,
126                      Error **errp);
127     int (*bdrv_file_open)(BlockDriverState *bs, QDict *options, int flags,
128                           Error **errp);
129     void (*bdrv_close)(BlockDriverState *bs);
130     int (*bdrv_create)(const char *filename, QemuOpts *opts, Error **errp);
131     int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
132     int (*bdrv_make_empty)(BlockDriverState *bs);
133 
134     void (*bdrv_refresh_filename)(BlockDriverState *bs, QDict *options);
135 
136     /* aio */
137     BlockAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
138         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
139         BlockCompletionFunc *cb, void *opaque);
140     BlockAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
141         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
142         BlockCompletionFunc *cb, void *opaque);
143     BlockAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
144         BlockCompletionFunc *cb, void *opaque);
145     BlockAIOCB *(*bdrv_aio_discard)(BlockDriverState *bs,
146         int64_t sector_num, int nb_sectors,
147         BlockCompletionFunc *cb, void *opaque);
148 
149     int coroutine_fn (*bdrv_co_readv)(BlockDriverState *bs,
150         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
151     int coroutine_fn (*bdrv_co_preadv)(BlockDriverState *bs,
152         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags);
153     int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
154         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
155     int coroutine_fn (*bdrv_co_writev_flags)(BlockDriverState *bs,
156         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int flags);
157     int coroutine_fn (*bdrv_co_pwritev)(BlockDriverState *bs,
158         uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags);
159 
160     /*
161      * Efficiently zero a region of the disk image.  Typically an image format
162      * would use a compact metadata representation to implement this.  This
163      * function pointer may be NULL or return -ENOSUP and .bdrv_co_writev()
164      * will be called instead.
165      */
166     int coroutine_fn (*bdrv_co_write_zeroes)(BlockDriverState *bs,
167         int64_t sector_num, int nb_sectors, BdrvRequestFlags flags);
168     int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
169         int64_t sector_num, int nb_sectors);
170     int64_t coroutine_fn (*bdrv_co_get_block_status)(BlockDriverState *bs,
171         int64_t sector_num, int nb_sectors, int *pnum,
172         BlockDriverState **file);
173 
174     /*
175      * Invalidate any cached meta-data.
176      */
177     void (*bdrv_invalidate_cache)(BlockDriverState *bs, Error **errp);
178     int (*bdrv_inactivate)(BlockDriverState *bs);
179 
180     /*
181      * Flushes all data for all layers by calling bdrv_co_flush for underlying
182      * layers, if needed. This function is needed for deterministic
183      * synchronization of the flush finishing callback.
184      */
185     int coroutine_fn (*bdrv_co_flush)(BlockDriverState *bs);
186 
187     /*
188      * Flushes all data that was already written to the OS all the way down to
189      * the disk (for example raw-posix calls fsync()).
190      */
191     int coroutine_fn (*bdrv_co_flush_to_disk)(BlockDriverState *bs);
192 
193     /*
194      * Flushes all internal caches to the OS. The data may still sit in a
195      * writeback cache of the host OS, but it will survive a crash of the qemu
196      * process.
197      */
198     int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
199 
200     const char *protocol_name;
201     int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
202 
203     int64_t (*bdrv_getlength)(BlockDriverState *bs);
204     bool has_variable_length;
205     int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs);
206 
207     int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
208                                  const uint8_t *buf, int nb_sectors);
209 
210     int (*bdrv_snapshot_create)(BlockDriverState *bs,
211                                 QEMUSnapshotInfo *sn_info);
212     int (*bdrv_snapshot_goto)(BlockDriverState *bs,
213                               const char *snapshot_id);
214     int (*bdrv_snapshot_delete)(BlockDriverState *bs,
215                                 const char *snapshot_id,
216                                 const char *name,
217                                 Error **errp);
218     int (*bdrv_snapshot_list)(BlockDriverState *bs,
219                               QEMUSnapshotInfo **psn_info);
220     int (*bdrv_snapshot_load_tmp)(BlockDriverState *bs,
221                                   const char *snapshot_id,
222                                   const char *name,
223                                   Error **errp);
224     int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
225     ImageInfoSpecific *(*bdrv_get_specific_info)(BlockDriverState *bs);
226 
227     int (*bdrv_save_vmstate)(BlockDriverState *bs, QEMUIOVector *qiov,
228                              int64_t pos);
229     int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
230                              int64_t pos, int size);
231 
232     int (*bdrv_change_backing_file)(BlockDriverState *bs,
233         const char *backing_file, const char *backing_fmt);
234 
235     /* removable device specific */
236     bool (*bdrv_is_inserted)(BlockDriverState *bs);
237     int (*bdrv_media_changed)(BlockDriverState *bs);
238     void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
239     void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
240 
241     /* to control generic scsi devices */
242     BlockAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
243         unsigned long int req, void *buf,
244         BlockCompletionFunc *cb, void *opaque);
245 
246     /* List of options for creating images, terminated by name == NULL */
247     QemuOptsList *create_opts;
248 
249     /*
250      * Returns 0 for completed check, -errno for internal errors.
251      * The check results are stored in result.
252      */
253     int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result,
254         BdrvCheckMode fix);
255 
256     int (*bdrv_amend_options)(BlockDriverState *bs, QemuOpts *opts,
257                               BlockDriverAmendStatusCB *status_cb,
258                               void *cb_opaque);
259 
260     void (*bdrv_debug_event)(BlockDriverState *bs, BlkdebugEvent event);
261 
262     /* TODO Better pass a option string/QDict/QemuOpts to add any rule? */
263     int (*bdrv_debug_breakpoint)(BlockDriverState *bs, const char *event,
264         const char *tag);
265     int (*bdrv_debug_remove_breakpoint)(BlockDriverState *bs,
266         const char *tag);
267     int (*bdrv_debug_resume)(BlockDriverState *bs, const char *tag);
268     bool (*bdrv_debug_is_suspended)(BlockDriverState *bs, const char *tag);
269 
270     void (*bdrv_refresh_limits)(BlockDriverState *bs, Error **errp);
271 
272     /*
273      * Returns 1 if newly created images are guaranteed to contain only
274      * zeros, 0 otherwise.
275      */
276     int (*bdrv_has_zero_init)(BlockDriverState *bs);
277 
278     /* Remove fd handlers, timers, and other event loop callbacks so the event
279      * loop is no longer in use.  Called with no in-flight requests and in
280      * depth-first traversal order with parents before child nodes.
281      */
282     void (*bdrv_detach_aio_context)(BlockDriverState *bs);
283 
284     /* Add fd handlers, timers, and other event loop callbacks so I/O requests
285      * can be processed again.  Called with no in-flight requests and in
286      * depth-first traversal order with child nodes before parent nodes.
287      */
288     void (*bdrv_attach_aio_context)(BlockDriverState *bs,
289                                     AioContext *new_context);
290 
291     /* io queue for linux-aio */
292     void (*bdrv_io_plug)(BlockDriverState *bs);
293     void (*bdrv_io_unplug)(BlockDriverState *bs);
294 
295     /**
296      * Try to get @bs's logical and physical block size.
297      * On success, store them in @bsz and return zero.
298      * On failure, return negative errno.
299      */
300     int (*bdrv_probe_blocksizes)(BlockDriverState *bs, BlockSizes *bsz);
301     /**
302      * Try to get @bs's geometry (cyls, heads, sectors)
303      * On success, store them in @geo and return 0.
304      * On failure return -errno.
305      * Only drivers that want to override guest geometry implement this
306      * callback; see hd_geometry_guess().
307      */
308     int (*bdrv_probe_geometry)(BlockDriverState *bs, HDGeometry *geo);
309 
310     /**
311      * Drain and stop any internal sources of requests in the driver, and
312      * remain so until next I/O callback (e.g. bdrv_co_writev) is called.
313      */
314     void (*bdrv_drain)(BlockDriverState *bs);
315 
316     void (*bdrv_add_child)(BlockDriverState *parent, BlockDriverState *child,
317                            Error **errp);
318     void (*bdrv_del_child)(BlockDriverState *parent, BdrvChild *child,
319                            Error **errp);
320 
321     QLIST_ENTRY(BlockDriver) list;
322 };
323 
324 typedef struct BlockLimits {
325     /* maximum number of sectors that can be discarded at once */
326     int max_discard;
327 
328     /* optimal alignment for discard requests in sectors */
329     int64_t discard_alignment;
330 
331     /* maximum number of sectors that can zeroized at once */
332     int max_write_zeroes;
333 
334     /* optimal alignment for write zeroes requests in sectors */
335     int64_t write_zeroes_alignment;
336 
337     /* optimal transfer length in sectors */
338     int opt_transfer_length;
339 
340     /* maximal transfer length in sectors */
341     int max_transfer_length;
342 
343     /* memory alignment so that no bounce buffer is needed */
344     size_t min_mem_alignment;
345 
346     /* memory alignment for bounce buffer */
347     size_t opt_mem_alignment;
348 
349     /* maximum number of iovec elements */
350     int max_iov;
351 } BlockLimits;
352 
353 typedef struct BdrvOpBlocker BdrvOpBlocker;
354 
355 typedef struct BdrvAioNotifier {
356     void (*attached_aio_context)(AioContext *new_context, void *opaque);
357     void (*detach_aio_context)(void *opaque);
358 
359     void *opaque;
360 
361     QLIST_ENTRY(BdrvAioNotifier) list;
362 } BdrvAioNotifier;
363 
364 struct BdrvChildRole {
365     void (*inherit_options)(int *child_flags, QDict *child_options,
366                             int parent_flags, QDict *parent_options);
367 
368     void (*change_media)(BdrvChild *child, bool load);
369     void (*resize)(BdrvChild *child);
370 
371     /* Returns a name that is supposedly more useful for human users than the
372      * node name for identifying the node in question (in particular, a BB
373      * name), or NULL if the parent can't provide a better name. */
374     const char* (*get_name)(BdrvChild *child);
375 
376     /*
377      * If this pair of functions is implemented, the parent doesn't issue new
378      * requests after returning from .drained_begin() until .drained_end() is
379      * called.
380      *
381      * Note that this can be nested. If drained_begin() was called twice, new
382      * I/O is allowed only after drained_end() was called twice, too.
383      */
384     void (*drained_begin)(BdrvChild *child);
385     void (*drained_end)(BdrvChild *child);
386 };
387 
388 extern const BdrvChildRole child_file;
389 extern const BdrvChildRole child_format;
390 
391 struct BdrvChild {
392     BlockDriverState *bs;
393     char *name;
394     const BdrvChildRole *role;
395     void *opaque;
396     QLIST_ENTRY(BdrvChild) next;
397     QLIST_ENTRY(BdrvChild) next_parent;
398 };
399 
400 /*
401  * Note: the function bdrv_append() copies and swaps contents of
402  * BlockDriverStates, so if you add new fields to this struct, please
403  * inspect bdrv_append() to determine if the new fields need to be
404  * copied as well.
405  */
406 struct BlockDriverState {
407     int64_t total_sectors; /* if we are reading a disk image, give its
408                               size in sectors */
409     int read_only; /* if true, the media is read only */
410     int open_flags; /* flags used to open the file, re-used for re-open */
411     int encrypted; /* if true, the media is encrypted */
412     int valid_key; /* if true, a valid encryption key has been set */
413     int sg;        /* if true, the device is a /dev/sg* */
414     int copy_on_read; /* if true, copy read backing sectors into image
415                          note this is a reference count */
416     bool probed;
417 
418     BlockDriver *drv; /* NULL means no media */
419     void *opaque;
420 
421     AioContext *aio_context; /* event loop used for fd handlers, timers, etc */
422     /* long-running tasks intended to always use the same AioContext as this
423      * BDS may register themselves in this list to be notified of changes
424      * regarding this BDS's context */
425     QLIST_HEAD(, BdrvAioNotifier) aio_notifiers;
426 
427     char filename[PATH_MAX];
428     char backing_file[PATH_MAX]; /* if non zero, the image is a diff of
429                                     this file image */
430     char backing_format[16]; /* if non-zero and backing_file exists */
431 
432     QDict *full_open_options;
433     char exact_filename[PATH_MAX];
434 
435     BdrvChild *backing;
436     BdrvChild *file;
437 
438     /* Callback before write request is processed */
439     NotifierWithReturnList before_write_notifiers;
440 
441     /* number of in-flight serialising requests */
442     unsigned int serialising_in_flight;
443 
444     /* Offset after the highest byte written to */
445     uint64_t wr_highest_offset;
446 
447     /* I/O Limits */
448     BlockLimits bl;
449 
450     /* Whether produces zeros when read beyond eof */
451     bool zero_beyond_eof;
452 
453     /* Alignment requirement for offset/length of I/O requests */
454     unsigned int request_alignment;
455     /* Flags honored during pwrite (so far: BDRV_REQ_FUA) */
456     unsigned int supported_write_flags;
457     /* Flags honored during write_zeroes (so far: BDRV_REQ_FUA,
458      * BDRV_REQ_MAY_UNMAP) */
459     unsigned int supported_zero_flags;
460 
461     /* the following member gives a name to every node on the bs graph. */
462     char node_name[32];
463     /* element of the list of named nodes building the graph */
464     QTAILQ_ENTRY(BlockDriverState) node_list;
465     /* element of the list of all BlockDriverStates (all_bdrv_states) */
466     QTAILQ_ENTRY(BlockDriverState) bs_list;
467     /* element of the list of monitor-owned BDS */
468     QTAILQ_ENTRY(BlockDriverState) monitor_list;
469     QLIST_HEAD(, BdrvDirtyBitmap) dirty_bitmaps;
470     int refcnt;
471 
472     QLIST_HEAD(, BdrvTrackedRequest) tracked_requests;
473 
474     /* operation blockers */
475     QLIST_HEAD(, BdrvOpBlocker) op_blockers[BLOCK_OP_TYPE_MAX];
476 
477     /* long-running background operation */
478     BlockJob *job;
479 
480     /* The node that this node inherited default options from (and a reopen on
481      * which can affect this node by changing these defaults). This is always a
482      * parent node of this node. */
483     BlockDriverState *inherits_from;
484     QLIST_HEAD(, BdrvChild) children;
485     QLIST_HEAD(, BdrvChild) parents;
486 
487     QDict *options;
488     QDict *explicit_options;
489     BlockdevDetectZeroesOptions detect_zeroes;
490 
491     /* The error object in use for blocking operations on backing_hd */
492     Error *backing_blocker;
493 
494     /* threshold limit for writes, in bytes. "High water mark". */
495     uint64_t write_threshold_offset;
496     NotifierWithReturn write_threshold_notifier;
497 
498     /* counters for nested bdrv_io_plug and bdrv_io_unplugged_begin */
499     unsigned io_plugged;
500     unsigned io_plug_disabled;
501 
502     int quiesce_counter;
503 };
504 
505 struct BlockBackendRootState {
506     int open_flags;
507     bool read_only;
508     BlockdevDetectZeroesOptions detect_zeroes;
509 };
510 
511 static inline BlockDriverState *backing_bs(BlockDriverState *bs)
512 {
513     return bs->backing ? bs->backing->bs : NULL;
514 }
515 
516 
517 /* Essential block drivers which must always be statically linked into qemu, and
518  * which therefore can be accessed without using bdrv_find_format() */
519 extern BlockDriver bdrv_file;
520 extern BlockDriver bdrv_raw;
521 extern BlockDriver bdrv_qcow2;
522 
523 /**
524  * bdrv_setup_io_funcs:
525  *
526  * Prepare a #BlockDriver for I/O request processing by populating
527  * unimplemented coroutine and AIO interfaces with generic wrapper functions
528  * that fall back to implemented interfaces.
529  */
530 void bdrv_setup_io_funcs(BlockDriver *bdrv);
531 
532 int coroutine_fn bdrv_co_preadv(BlockDriverState *bs,
533     int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
534     BdrvRequestFlags flags);
535 int coroutine_fn bdrv_co_pwritev(BlockDriverState *bs,
536     int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
537     BdrvRequestFlags flags);
538 
539 int get_tmp_filename(char *filename, int size);
540 BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
541                             const char *filename);
542 
543 
544 /**
545  * bdrv_add_before_write_notifier:
546  *
547  * Register a callback that is invoked before write requests are processed but
548  * after any throttling or waiting for overlapping requests.
549  */
550 void bdrv_add_before_write_notifier(BlockDriverState *bs,
551                                     NotifierWithReturn *notifier);
552 
553 /**
554  * bdrv_detach_aio_context:
555  *
556  * May be called from .bdrv_detach_aio_context() to detach children from the
557  * current #AioContext.  This is only needed by block drivers that manage their
558  * own children.  Both ->file and ->backing are automatically handled and
559  * block drivers should not call this function on them explicitly.
560  */
561 void bdrv_detach_aio_context(BlockDriverState *bs);
562 
563 /**
564  * bdrv_attach_aio_context:
565  *
566  * May be called from .bdrv_attach_aio_context() to attach children to the new
567  * #AioContext.  This is only needed by block drivers that manage their own
568  * children.  Both ->file and ->backing are automatically handled and block
569  * drivers should not call this function on them explicitly.
570  */
571 void bdrv_attach_aio_context(BlockDriverState *bs,
572                              AioContext *new_context);
573 
574 /**
575  * bdrv_add_aio_context_notifier:
576  *
577  * If a long-running job intends to be always run in the same AioContext as a
578  * certain BDS, it may use this function to be notified of changes regarding the
579  * association of the BDS to an AioContext.
580  *
581  * attached_aio_context() is called after the target BDS has been attached to a
582  * new AioContext; detach_aio_context() is called before the target BDS is being
583  * detached from its old AioContext.
584  */
585 void bdrv_add_aio_context_notifier(BlockDriverState *bs,
586         void (*attached_aio_context)(AioContext *new_context, void *opaque),
587         void (*detach_aio_context)(void *opaque), void *opaque);
588 
589 /**
590  * bdrv_remove_aio_context_notifier:
591  *
592  * Unsubscribe of change notifications regarding the BDS's AioContext. The
593  * parameters given here have to be the same as those given to
594  * bdrv_add_aio_context_notifier().
595  */
596 void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
597                                       void (*aio_context_attached)(AioContext *,
598                                                                    void *),
599                                       void (*aio_context_detached)(void *),
600                                       void *opaque);
601 
602 #ifdef _WIN32
603 int is_windows_drive(const char *filename);
604 #endif
605 
606 /**
607  * stream_start:
608  * @bs: Block device to operate on.
609  * @base: Block device that will become the new base, or %NULL to
610  * flatten the whole backing file chain onto @bs.
611  * @base_id: The file name that will be written to @bs as the new
612  * backing file if the job completes.  Ignored if @base is %NULL.
613  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
614  * @on_error: The action to take upon error.
615  * @cb: Completion function for the job.
616  * @opaque: Opaque pointer value passed to @cb.
617  * @errp: Error object.
618  *
619  * Start a streaming operation on @bs.  Clusters that are unallocated
620  * in @bs, but allocated in any image between @base and @bs (both
621  * exclusive) will be written to @bs.  At the end of a successful
622  * streaming job, the backing file of @bs will be changed to
623  * @base_id in the written image and to @base in the live BlockDriverState.
624  */
625 void stream_start(BlockDriverState *bs, BlockDriverState *base,
626                   const char *base_id, int64_t speed, BlockdevOnError on_error,
627                   BlockCompletionFunc *cb,
628                   void *opaque, Error **errp);
629 
630 /**
631  * commit_start:
632  * @bs: Active block device.
633  * @top: Top block device to be committed.
634  * @base: Block device that will be written into, and become the new top.
635  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
636  * @on_error: The action to take upon error.
637  * @cb: Completion function for the job.
638  * @opaque: Opaque pointer value passed to @cb.
639  * @backing_file_str: String to use as the backing file in @top's overlay
640  * @errp: Error object.
641  *
642  */
643 void commit_start(BlockDriverState *bs, BlockDriverState *base,
644                  BlockDriverState *top, int64_t speed,
645                  BlockdevOnError on_error, BlockCompletionFunc *cb,
646                  void *opaque, const char *backing_file_str, Error **errp);
647 /**
648  * commit_active_start:
649  * @bs: Active block device to be committed.
650  * @base: Block device that will be written into, and become the new top.
651  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
652  * @on_error: The action to take upon error.
653  * @cb: Completion function for the job.
654  * @opaque: Opaque pointer value passed to @cb.
655  * @errp: Error object.
656  *
657  */
658 void commit_active_start(BlockDriverState *bs, BlockDriverState *base,
659                          int64_t speed,
660                          BlockdevOnError on_error,
661                          BlockCompletionFunc *cb,
662                          void *opaque, Error **errp);
663 /*
664  * mirror_start:
665  * @bs: Block device to operate on.
666  * @target: Block device to write to.
667  * @replaces: Block graph node name to replace once the mirror is done. Can
668  *            only be used when full mirroring is selected.
669  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
670  * @granularity: The chosen granularity for the dirty bitmap.
671  * @buf_size: The amount of data that can be in flight at one time.
672  * @mode: Whether to collapse all images in the chain to the target.
673  * @on_source_error: The action to take upon error reading from the source.
674  * @on_target_error: The action to take upon error writing to the target.
675  * @unmap: Whether to unmap target where source sectors only contain zeroes.
676  * @cb: Completion function for the job.
677  * @opaque: Opaque pointer value passed to @cb.
678  * @errp: Error object.
679  *
680  * Start a mirroring operation on @bs.  Clusters that are allocated
681  * in @bs will be written to @bs until the job is cancelled or
682  * manually completed.  At the end of a successful mirroring job,
683  * @bs will be switched to read from @target.
684  */
685 void mirror_start(BlockDriverState *bs, BlockDriverState *target,
686                   const char *replaces,
687                   int64_t speed, uint32_t granularity, int64_t buf_size,
688                   MirrorSyncMode mode, BlockdevOnError on_source_error,
689                   BlockdevOnError on_target_error,
690                   bool unmap,
691                   BlockCompletionFunc *cb,
692                   void *opaque, Error **errp);
693 
694 /*
695  * backup_start:
696  * @bs: Block device to operate on.
697  * @target: Block device to write to.
698  * @speed: The maximum speed, in bytes per second, or 0 for unlimited.
699  * @sync_mode: What parts of the disk image should be copied to the destination.
700  * @sync_bitmap: The dirty bitmap if sync_mode is MIRROR_SYNC_MODE_INCREMENTAL.
701  * @on_source_error: The action to take upon error reading from the source.
702  * @on_target_error: The action to take upon error writing to the target.
703  * @cb: Completion function for the job.
704  * @opaque: Opaque pointer value passed to @cb.
705  * @txn: Transaction that this job is part of (may be NULL).
706  *
707  * Start a backup operation on @bs.  Clusters in @bs are written to @target
708  * until the job is cancelled or manually completed.
709  */
710 void backup_start(BlockDriverState *bs, BlockDriverState *target,
711                   int64_t speed, MirrorSyncMode sync_mode,
712                   BdrvDirtyBitmap *sync_bitmap,
713                   BlockdevOnError on_source_error,
714                   BlockdevOnError on_target_error,
715                   BlockCompletionFunc *cb, void *opaque,
716                   BlockJobTxn *txn, Error **errp);
717 
718 void hmp_drive_add_node(Monitor *mon, const char *optstr);
719 
720 BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
721                                   const char *child_name,
722                                   const BdrvChildRole *child_role,
723                                   void *opaque);
724 void bdrv_root_unref_child(BdrvChild *child);
725 
726 const char *bdrv_get_parent_name(const BlockDriverState *bs);
727 void blk_dev_change_media_cb(BlockBackend *blk, bool load);
728 bool blk_dev_has_removable_media(BlockBackend *blk);
729 bool blk_dev_has_tray(BlockBackend *blk);
730 void blk_dev_eject_request(BlockBackend *blk, bool force);
731 bool blk_dev_is_tray_open(BlockBackend *blk);
732 bool blk_dev_is_medium_locked(BlockBackend *blk);
733 
734 void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, int nr_sectors);
735 bool bdrv_requests_pending(BlockDriverState *bs);
736 
737 void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out);
738 void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in);
739 
740 void blockdev_close_all_bdrv_states(void);
741 
742 #endif /* BLOCK_INT_H */
743