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3b491a90 EGE |
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_IO_H | |
25 | #define BLOCK_IO_H | |
26 | ||
e2c1c34f MA |
27 | #include "block/aio-wait.h" |
28 | #include "block/block-common.h" | |
29 | #include "qemu/coroutine.h" | |
30 | #include "qemu/iov.h" | |
3b491a90 EGE |
31 | |
32 | /* | |
33 | * I/O API functions. These functions are thread-safe, and therefore | |
34 | * can run in any thread as long as the thread has called | |
35 | * aio_context_acquire/release(). | |
36 | * | |
37 | * These functions can only call functions from I/O and Common categories, | |
38 | * but can be invoked by GS, "I/O or GS" and I/O APIs. | |
39 | * | |
40 | * All functions in this category must use the macro | |
41 | * IO_CODE(); | |
42 | * to catch when they are accidentally called by the wrong API. | |
43 | */ | |
44 | ||
90830f59 EGE |
45 | int co_wrapper_mixed_bdrv_rdlock |
46 | bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset, int64_t bytes, | |
47 | BdrvRequestFlags flags); | |
48 | ||
3b491a90 | 49 | int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags); |
90830f59 EGE |
50 | |
51 | int co_wrapper_mixed_bdrv_rdlock | |
52 | bdrv_pread(BdrvChild *child, int64_t offset, int64_t bytes, void *buf, | |
53 | BdrvRequestFlags flags); | |
54 | ||
55 | int co_wrapper_mixed_bdrv_rdlock | |
56 | bdrv_pwrite(BdrvChild *child, int64_t offset,int64_t bytes, | |
57 | const void *buf, BdrvRequestFlags flags); | |
58 | ||
59 | int co_wrapper_mixed_bdrv_rdlock | |
60 | bdrv_pwrite_sync(BdrvChild *child, int64_t offset, int64_t bytes, | |
61 | const void *buf, BdrvRequestFlags flags); | |
62 | ||
e97190a4 AF |
63 | int coroutine_fn bdrv_co_pwrite_sync(BdrvChild *child, int64_t offset, |
64 | int64_t bytes, const void *buf, | |
65 | BdrvRequestFlags flags); | |
3b491a90 EGE |
66 | /* |
67 | * Efficiently zero a region of the disk image. Note that this is a regular | |
68 | * I/O request like read or write and should have a reasonable size. This | |
69 | * function is not suitable for zeroing the entire image in a single request | |
70 | * because it may allocate memory for the entire region. | |
71 | */ | |
72 | int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset, | |
73 | int64_t bytes, BdrvRequestFlags flags); | |
74 | ||
75 | int coroutine_fn bdrv_co_truncate(BdrvChild *child, int64_t offset, bool exact, | |
76 | PreallocMode prealloc, BdrvRequestFlags flags, | |
77 | Error **errp); | |
78 | ||
79 | int64_t bdrv_nb_sectors(BlockDriverState *bs); | |
80 | int64_t bdrv_getlength(BlockDriverState *bs); | |
81 | int64_t bdrv_get_allocated_file_size(BlockDriverState *bs); | |
82 | BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts, | |
83 | BlockDriverState *in_bs, Error **errp); | |
84 | void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr); | |
85 | int coroutine_fn bdrv_co_delete_file(BlockDriverState *bs, Error **errp); | |
86 | void coroutine_fn bdrv_co_delete_file_noerr(BlockDriverState *bs); | |
87 | ||
88 | ||
89 | /* async block I/O */ | |
90 | void bdrv_aio_cancel(BlockAIOCB *acb); | |
91 | void bdrv_aio_cancel_async(BlockAIOCB *acb); | |
92 | ||
93 | /* sg packet commands */ | |
16bb776f | 94 | int coroutine_fn bdrv_co_ioctl(BlockDriverState *bs, int req, void *buf); |
3b491a90 EGE |
95 | |
96 | /* Ensure contents are flushed to disk. */ | |
97 | int coroutine_fn bdrv_co_flush(BlockDriverState *bs); | |
98 | ||
16bb776f AF |
99 | int coroutine_fn bdrv_co_pdiscard(BdrvChild *child, int64_t offset, |
100 | int64_t bytes); | |
3b491a90 EGE |
101 | bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs); |
102 | int bdrv_block_status(BlockDriverState *bs, int64_t offset, | |
103 | int64_t bytes, int64_t *pnum, int64_t *map, | |
104 | BlockDriverState **file); | |
7b52a921 EGE |
105 | |
106 | int coroutine_fn bdrv_co_block_status_above(BlockDriverState *bs, | |
107 | BlockDriverState *base, | |
108 | int64_t offset, int64_t bytes, | |
109 | int64_t *pnum, int64_t *map, | |
110 | BlockDriverState **file); | |
3b491a90 EGE |
111 | int bdrv_block_status_above(BlockDriverState *bs, BlockDriverState *base, |
112 | int64_t offset, int64_t bytes, int64_t *pnum, | |
113 | int64_t *map, BlockDriverState **file); | |
7b52a921 EGE |
114 | |
115 | int coroutine_fn bdrv_co_is_allocated(BlockDriverState *bs, int64_t offset, | |
116 | int64_t bytes, int64_t *pnum); | |
3b491a90 EGE |
117 | int bdrv_is_allocated(BlockDriverState *bs, int64_t offset, int64_t bytes, |
118 | int64_t *pnum); | |
7b52a921 EGE |
119 | |
120 | int coroutine_fn bdrv_co_is_allocated_above(BlockDriverState *top, | |
121 | BlockDriverState *base, | |
122 | bool include_base, int64_t offset, | |
123 | int64_t bytes, int64_t *pnum); | |
3b491a90 EGE |
124 | int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base, |
125 | bool include_base, int64_t offset, int64_t bytes, | |
126 | int64_t *pnum); | |
7b52a921 | 127 | |
3b491a90 EGE |
128 | int coroutine_fn bdrv_co_is_zero_fast(BlockDriverState *bs, int64_t offset, |
129 | int64_t bytes); | |
130 | ||
131 | int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only, | |
132 | bool ignore_allow_rdw, Error **errp); | |
133 | int bdrv_apply_auto_read_only(BlockDriverState *bs, const char *errmsg, | |
134 | Error **errp); | |
135 | bool bdrv_is_read_only(BlockDriverState *bs); | |
136 | bool bdrv_is_writable(BlockDriverState *bs); | |
137 | bool bdrv_is_sg(BlockDriverState *bs); | |
15aee7ac | 138 | int bdrv_get_flags(BlockDriverState *bs); |
1e97be91 EGE |
139 | |
140 | bool coroutine_fn bdrv_co_is_inserted(BlockDriverState *bs); | |
141 | bool co_wrapper bdrv_is_inserted(BlockDriverState *bs); | |
142 | ||
3b491a90 EGE |
143 | void bdrv_lock_medium(BlockDriverState *bs, bool locked); |
144 | void bdrv_eject(BlockDriverState *bs, bool eject_flag); | |
145 | const char *bdrv_get_format_name(BlockDriverState *bs); | |
146 | ||
147 | bool bdrv_supports_compressed_writes(BlockDriverState *bs); | |
148 | const char *bdrv_get_node_name(const BlockDriverState *bs); | |
149 | const char *bdrv_get_device_name(const BlockDriverState *bs); | |
150 | const char *bdrv_get_device_or_node_name(const BlockDriverState *bs); | |
151 | int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi); | |
152 | ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs, | |
153 | Error **errp); | |
154 | BlockStatsSpecific *bdrv_get_specific_stats(BlockDriverState *bs); | |
155 | void bdrv_round_to_clusters(BlockDriverState *bs, | |
156 | int64_t offset, int64_t bytes, | |
157 | int64_t *cluster_offset, | |
158 | int64_t *cluster_bytes); | |
159 | ||
160 | void bdrv_get_backing_filename(BlockDriverState *bs, | |
161 | char *filename, int filename_size); | |
162 | ||
163 | int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf, | |
164 | int64_t pos, int size); | |
165 | ||
166 | int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf, | |
167 | int64_t pos, int size); | |
168 | ||
169 | /* | |
170 | * Returns the alignment in bytes that is required so that no bounce buffer | |
171 | * is required throughout the stack | |
172 | */ | |
173 | size_t bdrv_min_mem_align(BlockDriverState *bs); | |
174 | /* Returns optimal alignment in bytes for bounce buffer */ | |
175 | size_t bdrv_opt_mem_align(BlockDriverState *bs); | |
176 | void *qemu_blockalign(BlockDriverState *bs, size_t size); | |
177 | void *qemu_blockalign0(BlockDriverState *bs, size_t size); | |
178 | void *qemu_try_blockalign(BlockDriverState *bs, size_t size); | |
179 | void *qemu_try_blockalign0(BlockDriverState *bs, size_t size); | |
3b491a90 EGE |
180 | |
181 | void bdrv_enable_copy_on_read(BlockDriverState *bs); | |
182 | void bdrv_disable_copy_on_read(BlockDriverState *bs); | |
183 | ||
184 | void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event); | |
185 | ||
186 | #define BLKDBG_EVENT(child, evt) \ | |
187 | do { \ | |
188 | if (child) { \ | |
189 | bdrv_debug_event(child->bs, evt); \ | |
190 | } \ | |
191 | } while (0) | |
192 | ||
193 | /** | |
194 | * bdrv_get_aio_context: | |
195 | * | |
196 | * Returns: the currently bound #AioContext | |
197 | */ | |
198 | AioContext *bdrv_get_aio_context(BlockDriverState *bs); | |
199 | ||
d5f8d79c HR |
200 | AioContext *bdrv_child_get_parent_aio_context(BdrvChild *c); |
201 | ||
3b491a90 EGE |
202 | /** |
203 | * Move the current coroutine to the AioContext of @bs and return the old | |
204 | * AioContext of the coroutine. Increase bs->in_flight so that draining @bs | |
205 | * will wait for the operation to proceed until the corresponding | |
206 | * bdrv_co_leave(). | |
207 | * | |
208 | * Consequently, you can't call drain inside a bdrv_co_enter/leave() section as | |
209 | * this will deadlock. | |
210 | */ | |
211 | AioContext *coroutine_fn bdrv_co_enter(BlockDriverState *bs); | |
212 | ||
213 | /** | |
214 | * Ends a section started by bdrv_co_enter(). Move the current coroutine back | |
215 | * to old_ctx and decrease bs->in_flight again. | |
216 | */ | |
217 | void coroutine_fn bdrv_co_leave(BlockDriverState *bs, AioContext *old_ctx); | |
218 | ||
3b491a90 EGE |
219 | AioContext *child_of_bds_get_parent_aio_context(BdrvChild *c); |
220 | ||
8f497454 | 221 | void coroutine_fn bdrv_co_io_plug(BlockDriverState *bs); |
09d9fc97 | 222 | void coroutine_fn bdrv_co_io_unplug(BlockDriverState *bs); |
3b491a90 | 223 | |
0508d0be EGE |
224 | bool coroutine_fn bdrv_co_can_store_new_dirty_bitmap(BlockDriverState *bs, |
225 | const char *name, | |
226 | uint32_t granularity, | |
227 | Error **errp); | |
228 | bool co_wrapper bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, | |
229 | const char *name, | |
230 | uint32_t granularity, | |
231 | Error **errp); | |
3b491a90 EGE |
232 | |
233 | /** | |
234 | * | |
235 | * bdrv_co_copy_range: | |
236 | * | |
237 | * Do offloaded copy between two children. If the operation is not implemented | |
238 | * by the driver, or if the backend storage doesn't support it, a negative | |
239 | * error code will be returned. | |
240 | * | |
241 | * Note: block layer doesn't emulate or fallback to a bounce buffer approach | |
242 | * because usually the caller shouldn't attempt offloaded copy any more (e.g. | |
243 | * calling copy_file_range(2)) after the first error, thus it should fall back | |
244 | * to a read+write path in the caller level. | |
245 | * | |
246 | * @src: Source child to copy data from | |
247 | * @src_offset: offset in @src image to read data | |
248 | * @dst: Destination child to copy data to | |
249 | * @dst_offset: offset in @dst image to write data | |
250 | * @bytes: number of bytes to copy | |
251 | * @flags: request flags. Supported flags: | |
252 | * BDRV_REQ_ZERO_WRITE - treat the @src range as zero data and do zero | |
253 | * write on @dst as if bdrv_co_pwrite_zeroes is | |
254 | * called. Used to simplify caller code, or | |
255 | * during BlockDriver.bdrv_co_copy_range_from() | |
256 | * recursion. | |
257 | * BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping | |
258 | * requests currently in flight. | |
259 | * | |
260 | * Returns: 0 if succeeded; negative error code if failed. | |
261 | **/ | |
262 | int coroutine_fn bdrv_co_copy_range(BdrvChild *src, int64_t src_offset, | |
263 | BdrvChild *dst, int64_t dst_offset, | |
264 | int64_t bytes, BdrvRequestFlags read_flags, | |
265 | BdrvRequestFlags write_flags); | |
266 | ||
3b491a90 EGE |
267 | /* |
268 | * "I/O or GS" API functions. These functions can run without | |
269 | * the BQL, but only in one specific iothread/main loop. | |
270 | * | |
271 | * More specifically, these functions use BDRV_POLL_WHILE(bs), which | |
272 | * requires the caller to be either in the main thread and hold | |
273 | * the BlockdriverState (bs) AioContext lock, or directly in the | |
274 | * home thread that runs the bs AioContext. Calling them from | |
275 | * another thread in another AioContext would cause deadlocks. | |
276 | * | |
277 | * Therefore, these functions are not proper I/O, because they | |
278 | * can't run in *any* iothreads, but only in a specific one. | |
279 | * | |
280 | * These functions can call any function from I/O, Common and this | |
281 | * categories, but must be invoked only by other "I/O or GS" and GS APIs. | |
282 | * | |
283 | * All functions in this category must use the macro | |
284 | * IO_OR_GS_CODE(); | |
285 | * to catch when they are accidentally called by the wrong API. | |
286 | */ | |
287 | ||
288 | #define BDRV_POLL_WHILE(bs, cond) ({ \ | |
289 | BlockDriverState *bs_ = (bs); \ | |
384a48fb | 290 | IO_OR_GS_CODE(); \ |
3b491a90 EGE |
291 | AIO_WAIT_WHILE(bdrv_get_aio_context(bs_), \ |
292 | cond); }) | |
293 | ||
294 | void bdrv_drain(BlockDriverState *bs); | |
3b491a90 | 295 | |
90830f59 | 296 | int co_wrapper_mixed_bdrv_rdlock |
3b491a90 EGE |
297 | bdrv_truncate(BdrvChild *child, int64_t offset, bool exact, |
298 | PreallocMode prealloc, BdrvRequestFlags flags, Error **errp); | |
299 | ||
90830f59 EGE |
300 | int co_wrapper_mixed_bdrv_rdlock |
301 | bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix); | |
3b491a90 EGE |
302 | |
303 | /* Invalidate any cached metadata used by image formats */ | |
90830f59 EGE |
304 | int co_wrapper_mixed_bdrv_rdlock |
305 | bdrv_invalidate_cache(BlockDriverState *bs, Error **errp); | |
306 | ||
307 | int co_wrapper_mixed_bdrv_rdlock bdrv_flush(BlockDriverState *bs); | |
308 | ||
309 | int co_wrapper_mixed_bdrv_rdlock | |
310 | bdrv_pdiscard(BdrvChild *child, int64_t offset, int64_t bytes); | |
311 | ||
312 | int co_wrapper_mixed_bdrv_rdlock | |
3b491a90 | 313 | bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos); |
90830f59 EGE |
314 | |
315 | int co_wrapper_mixed_bdrv_rdlock | |
3b491a90 EGE |
316 | bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos); |
317 | ||
318 | /** | |
319 | * bdrv_parent_drained_begin_single: | |
320 | * | |
606ed756 | 321 | * Begin a quiesced section for the parent of @c. |
3b491a90 | 322 | */ |
606ed756 | 323 | void bdrv_parent_drained_begin_single(BdrvChild *c); |
3b491a90 | 324 | |
23987471 KW |
325 | /** |
326 | * bdrv_parent_drained_poll_single: | |
327 | * | |
328 | * Returns true if there is any pending activity to cease before @c can be | |
329 | * called quiesced, false otherwise. | |
330 | */ | |
331 | bool bdrv_parent_drained_poll_single(BdrvChild *c); | |
332 | ||
3b491a90 EGE |
333 | /** |
334 | * bdrv_parent_drained_end_single: | |
335 | * | |
336 | * End a quiesced section for the parent of @c. | |
3b491a90 EGE |
337 | */ |
338 | void bdrv_parent_drained_end_single(BdrvChild *c); | |
339 | ||
340 | /** | |
341 | * bdrv_drain_poll: | |
342 | * | |
299403ae | 343 | * Poll for pending requests in @bs and its parents (except for @ignore_parent). |
3b491a90 EGE |
344 | * |
345 | * If @ignore_bds_parents is true, parents that are BlockDriverStates must | |
346 | * ignore the drain request because they will be drained separately (used for | |
347 | * drain_all). | |
348 | * | |
349 | * This is part of bdrv_drained_begin. | |
350 | */ | |
299403ae KW |
351 | bool bdrv_drain_poll(BlockDriverState *bs, BdrvChild *ignore_parent, |
352 | bool ignore_bds_parents); | |
3b491a90 EGE |
353 | |
354 | /** | |
355 | * bdrv_drained_begin: | |
356 | * | |
357 | * Begin a quiesced section for exclusive access to the BDS, by disabling | |
358 | * external request sources including NBD server, block jobs, and device model. | |
359 | * | |
360 | * This function can be recursive. | |
361 | */ | |
362 | void bdrv_drained_begin(BlockDriverState *bs); | |
363 | ||
364 | /** | |
365 | * bdrv_do_drained_begin_quiesce: | |
366 | * | |
367 | * Quiesces a BDS like bdrv_drained_begin(), but does not wait for already | |
368 | * running requests to complete. | |
369 | */ | |
a82a3bd1 | 370 | void bdrv_do_drained_begin_quiesce(BlockDriverState *bs, BdrvChild *parent); |
3b491a90 | 371 | |
3b491a90 EGE |
372 | /** |
373 | * bdrv_drained_end: | |
374 | * | |
375 | * End a quiescent section started by bdrv_drained_begin(). | |
3b491a90 EGE |
376 | */ |
377 | void bdrv_drained_end(BlockDriverState *bs); | |
378 | ||
3b491a90 | 379 | #endif /* BLOCK_IO_H */ |