Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 1 | /* |
Vladimir Sementsov-Ogievskiy | d003e0a | 2021-08-24 11:38:27 +0300 | [diff] [blame] | 2 | * copy-before-write filter driver |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 3 | * |
| 4 | * The driver performs Copy-Before-Write (CBW) operation: it is injected above |
| 5 | * some node, and before each write it copies _old_ data to the target node. |
| 6 | * |
Vladimir Sementsov-Ogievskiy | d003e0a | 2021-08-24 11:38:27 +0300 | [diff] [blame] | 7 | * Copyright (c) 2018-2021 Virtuozzo International GmbH. |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 8 | * |
| 9 | * Author: |
| 10 | * Sementsov-Ogievskiy Vladimir <vsementsov@virtuozzo.com> |
| 11 | * |
| 12 | * This program is free software; you can redistribute it and/or modify |
| 13 | * it under the terms of the GNU General Public License as published by |
| 14 | * the Free Software Foundation; either version 2 of the License, or |
| 15 | * (at your option) any later version. |
| 16 | * |
| 17 | * This program is distributed in the hope that it will be useful, |
| 18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | * GNU General Public License for more details. |
| 21 | * |
| 22 | * You should have received a copy of the GNU General Public License |
| 23 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 24 | */ |
| 25 | |
| 26 | #include "qemu/osdep.h" |
Vladimir Sementsov-Ogievskiy | 79ef0ce | 2022-04-07 16:27:20 +0300 | [diff] [blame] | 27 | #include "qapi/qmp/qjson.h" |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 28 | |
| 29 | #include "sysemu/block-backend.h" |
| 30 | #include "qemu/cutils.h" |
| 31 | #include "qapi/error.h" |
| 32 | #include "block/block_int.h" |
| 33 | #include "block/qdict.h" |
| 34 | #include "block/block-copy.h" |
Markus Armbruster | e2c1c34 | 2022-12-21 14:35:49 +0100 | [diff] [blame] | 35 | #include "block/dirty-bitmap.h" |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 36 | |
Vladimir Sementsov-Ogievskiy | d003e0a | 2021-08-24 11:38:27 +0300 | [diff] [blame] | 37 | #include "block/copy-before-write.h" |
Vladimir Sementsov-Ogievskiy | af5bcd7 | 2022-03-03 20:43:45 +0100 | [diff] [blame] | 38 | #include "block/reqlist.h" |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 39 | |
Vladimir Sementsov-Ogievskiy | 5f3a3cd | 2022-03-03 20:43:37 +0100 | [diff] [blame] | 40 | #include "qapi/qapi-visit-block-core.h" |
| 41 | |
Vladimir Sementsov-Ogievskiy | d003e0a | 2021-08-24 11:38:27 +0300 | [diff] [blame] | 42 | typedef struct BDRVCopyBeforeWriteState { |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 43 | BlockCopyState *bcs; |
| 44 | BdrvChild *target; |
Vladimir Sementsov-Ogievskiy | f1bb39a | 2022-04-07 16:27:21 +0300 | [diff] [blame] | 45 | OnCbwError on_cbw_error; |
Vladimir Sementsov-Ogievskiy | 6db7fd1 | 2022-04-07 16:27:25 +0300 | [diff] [blame] | 46 | uint32_t cbw_timeout_ns; |
Vladimir Sementsov-Ogievskiy | af5bcd7 | 2022-03-03 20:43:45 +0100 | [diff] [blame] | 47 | |
| 48 | /* |
| 49 | * @lock: protects access to @access_bitmap, @done_bitmap and |
| 50 | * @frozen_read_reqs |
| 51 | */ |
| 52 | CoMutex lock; |
| 53 | |
| 54 | /* |
| 55 | * @access_bitmap: represents areas allowed for reading by fleecing user. |
| 56 | * Reading from non-dirty areas leads to -EACCES. |
| 57 | */ |
| 58 | BdrvDirtyBitmap *access_bitmap; |
| 59 | |
| 60 | /* |
| 61 | * @done_bitmap: represents areas that was successfully copied to @target by |
| 62 | * copy-before-write operations. |
| 63 | */ |
| 64 | BdrvDirtyBitmap *done_bitmap; |
| 65 | |
| 66 | /* |
| 67 | * @frozen_read_reqs: current read requests for fleecing user in bs->file |
| 68 | * node. These areas must not be rewritten by guest. |
| 69 | */ |
| 70 | BlockReqList frozen_read_reqs; |
Vladimir Sementsov-Ogievskiy | f1bb39a | 2022-04-07 16:27:21 +0300 | [diff] [blame] | 71 | |
| 72 | /* |
| 73 | * @snapshot_error is normally zero. But on first copy-before-write failure |
| 74 | * when @on_cbw_error == ON_CBW_ERROR_BREAK_SNAPSHOT, @snapshot_error takes |
| 75 | * value of this error (<0). After that all in-flight and further |
| 76 | * snapshot-API requests will fail with that error. |
| 77 | */ |
| 78 | int snapshot_error; |
Vladimir Sementsov-Ogievskiy | d003e0a | 2021-08-24 11:38:27 +0300 | [diff] [blame] | 79 | } BDRVCopyBeforeWriteState; |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 80 | |
Kevin Wolf | b9b10c3 | 2023-02-03 16:21:50 +0100 | [diff] [blame] | 81 | static int coroutine_fn GRAPH_RDLOCK |
| 82 | cbw_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes, |
| 83 | QEMUIOVector *qiov, BdrvRequestFlags flags) |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 84 | { |
Vladimir Sementsov-Ogievskiy | 3c1e632 | 2021-08-24 11:38:34 +0300 | [diff] [blame] | 85 | return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags); |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 86 | } |
| 87 | |
Vladimir Sementsov-Ogievskiy | 6db7fd1 | 2022-04-07 16:27:25 +0300 | [diff] [blame] | 88 | static void block_copy_cb(void *opaque) |
| 89 | { |
| 90 | BlockDriverState *bs = opaque; |
| 91 | |
| 92 | bdrv_dec_in_flight(bs); |
| 93 | } |
| 94 | |
Vladimir Sementsov-Ogievskiy | af5bcd7 | 2022-03-03 20:43:45 +0100 | [diff] [blame] | 95 | /* |
| 96 | * Do copy-before-write operation. |
| 97 | * |
| 98 | * On failure guest request must be failed too. |
| 99 | * |
| 100 | * On success, we also wait for all in-flight fleecing read requests in source |
| 101 | * node, and it's guaranteed that after cbw_do_copy_before_write() successful |
| 102 | * return there are no such requests and they will never appear. |
| 103 | */ |
Vladimir Sementsov-Ogievskiy | d003e0a | 2021-08-24 11:38:27 +0300 | [diff] [blame] | 104 | static coroutine_fn int cbw_do_copy_before_write(BlockDriverState *bs, |
| 105 | uint64_t offset, uint64_t bytes, BdrvRequestFlags flags) |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 106 | { |
Vladimir Sementsov-Ogievskiy | d003e0a | 2021-08-24 11:38:27 +0300 | [diff] [blame] | 107 | BDRVCopyBeforeWriteState *s = bs->opaque; |
Vladimir Sementsov-Ogievskiy | af5bcd7 | 2022-03-03 20:43:45 +0100 | [diff] [blame] | 108 | int ret; |
Vladimir Sementsov-Ogievskiy | 4bc267a | 2020-02-07 19:12:31 +0300 | [diff] [blame] | 109 | uint64_t off, end; |
Vladimir Sementsov-Ogievskiy | b518e9e | 2021-08-24 11:38:31 +0300 | [diff] [blame] | 110 | int64_t cluster_size = block_copy_cluster_size(s->bcs); |
Vladimir Sementsov-Ogievskiy | 4bc267a | 2020-02-07 19:12:31 +0300 | [diff] [blame] | 111 | |
| 112 | if (flags & BDRV_REQ_WRITE_UNCHANGED) { |
| 113 | return 0; |
| 114 | } |
| 115 | |
Vladimir Sementsov-Ogievskiy | f1bb39a | 2022-04-07 16:27:21 +0300 | [diff] [blame] | 116 | if (s->snapshot_error) { |
| 117 | return 0; |
| 118 | } |
| 119 | |
Vladimir Sementsov-Ogievskiy | b518e9e | 2021-08-24 11:38:31 +0300 | [diff] [blame] | 120 | off = QEMU_ALIGN_DOWN(offset, cluster_size); |
| 121 | end = QEMU_ALIGN_UP(offset + bytes, cluster_size); |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 122 | |
Vladimir Sementsov-Ogievskiy | 6db7fd1 | 2022-04-07 16:27:25 +0300 | [diff] [blame] | 123 | /* |
| 124 | * Increase in_flight, so that in case of timed-out block-copy, the |
| 125 | * remaining background block_copy() request (which can't be immediately |
| 126 | * cancelled by timeout) is presented in bs->in_flight. This way we are |
| 127 | * sure that on bs close() we'll previously wait for all timed-out but yet |
| 128 | * running block_copy calls. |
| 129 | */ |
| 130 | bdrv_inc_in_flight(bs); |
| 131 | ret = block_copy(s->bcs, off, end - off, true, s->cbw_timeout_ns, |
| 132 | block_copy_cb, bs); |
Vladimir Sementsov-Ogievskiy | f1bb39a | 2022-04-07 16:27:21 +0300 | [diff] [blame] | 133 | if (ret < 0 && s->on_cbw_error == ON_CBW_ERROR_BREAK_GUEST_WRITE) { |
Vladimir Sementsov-Ogievskiy | af5bcd7 | 2022-03-03 20:43:45 +0100 | [diff] [blame] | 134 | return ret; |
| 135 | } |
| 136 | |
| 137 | WITH_QEMU_LOCK_GUARD(&s->lock) { |
Vladimir Sementsov-Ogievskiy | f1bb39a | 2022-04-07 16:27:21 +0300 | [diff] [blame] | 138 | if (ret < 0) { |
| 139 | assert(s->on_cbw_error == ON_CBW_ERROR_BREAK_SNAPSHOT); |
| 140 | if (!s->snapshot_error) { |
| 141 | s->snapshot_error = ret; |
| 142 | } |
| 143 | } else { |
| 144 | bdrv_set_dirty_bitmap(s->done_bitmap, off, end - off); |
| 145 | } |
Vladimir Sementsov-Ogievskiy | af5bcd7 | 2022-03-03 20:43:45 +0100 | [diff] [blame] | 146 | reqlist_wait_all(&s->frozen_read_reqs, off, end - off, &s->lock); |
| 147 | } |
| 148 | |
| 149 | return 0; |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 150 | } |
| 151 | |
Emanuele Giuseppe Esposito | 9a5a1c6 | 2023-02-03 16:21:47 +0100 | [diff] [blame] | 152 | static int coroutine_fn GRAPH_RDLOCK |
| 153 | cbw_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes) |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 154 | { |
Vladimir Sementsov-Ogievskiy | d003e0a | 2021-08-24 11:38:27 +0300 | [diff] [blame] | 155 | int ret = cbw_do_copy_before_write(bs, offset, bytes, 0); |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 156 | if (ret < 0) { |
| 157 | return ret; |
| 158 | } |
| 159 | |
Vladimir Sementsov-Ogievskiy | 3c1e632 | 2021-08-24 11:38:34 +0300 | [diff] [blame] | 160 | return bdrv_co_pdiscard(bs->file, offset, bytes); |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 161 | } |
| 162 | |
Kevin Wolf | abaf8b7 | 2023-02-03 16:21:48 +0100 | [diff] [blame] | 163 | static int coroutine_fn GRAPH_RDLOCK |
| 164 | cbw_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes, |
| 165 | BdrvRequestFlags flags) |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 166 | { |
Vladimir Sementsov-Ogievskiy | d003e0a | 2021-08-24 11:38:27 +0300 | [diff] [blame] | 167 | int ret = cbw_do_copy_before_write(bs, offset, bytes, flags); |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 168 | if (ret < 0) { |
| 169 | return ret; |
| 170 | } |
| 171 | |
Vladimir Sementsov-Ogievskiy | 3c1e632 | 2021-08-24 11:38:34 +0300 | [diff] [blame] | 172 | return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags); |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 173 | } |
| 174 | |
Kevin Wolf | b9b10c3 | 2023-02-03 16:21:50 +0100 | [diff] [blame] | 175 | static coroutine_fn GRAPH_RDLOCK |
| 176 | int cbw_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes, |
| 177 | QEMUIOVector *qiov, BdrvRequestFlags flags) |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 178 | { |
Vladimir Sementsov-Ogievskiy | d003e0a | 2021-08-24 11:38:27 +0300 | [diff] [blame] | 179 | int ret = cbw_do_copy_before_write(bs, offset, bytes, flags); |
Vladimir Sementsov-Ogievskiy | 4bc267a | 2020-02-07 19:12:31 +0300 | [diff] [blame] | 180 | if (ret < 0) { |
| 181 | return ret; |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 182 | } |
| 183 | |
Vladimir Sementsov-Ogievskiy | 3c1e632 | 2021-08-24 11:38:34 +0300 | [diff] [blame] | 184 | return bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags); |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 185 | } |
| 186 | |
Emanuele Giuseppe Esposito | 8809534 | 2023-02-03 16:21:46 +0100 | [diff] [blame] | 187 | static int coroutine_fn GRAPH_RDLOCK cbw_co_flush(BlockDriverState *bs) |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 188 | { |
Vladimir Sementsov-Ogievskiy | 3c1e632 | 2021-08-24 11:38:34 +0300 | [diff] [blame] | 189 | if (!bs->file) { |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 190 | return 0; |
| 191 | } |
| 192 | |
Vladimir Sementsov-Ogievskiy | 3c1e632 | 2021-08-24 11:38:34 +0300 | [diff] [blame] | 193 | return bdrv_co_flush(bs->file->bs); |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 194 | } |
| 195 | |
Vladimir Sementsov-Ogievskiy | af5bcd7 | 2022-03-03 20:43:45 +0100 | [diff] [blame] | 196 | /* |
| 197 | * If @offset not accessible - return NULL. |
| 198 | * |
| 199 | * Otherwise, set @pnum to some bytes that accessible from @file (@file is set |
| 200 | * to bs->file or to s->target). Return newly allocated BlockReq object that |
| 201 | * should be than passed to cbw_snapshot_read_unlock(). |
| 202 | * |
| 203 | * It's guaranteed that guest writes will not interact in the region until |
| 204 | * cbw_snapshot_read_unlock() called. |
| 205 | */ |
Paolo Bonzini | 3e61404 | 2022-09-22 10:49:13 +0200 | [diff] [blame] | 206 | static coroutine_fn BlockReq * |
| 207 | cbw_snapshot_read_lock(BlockDriverState *bs, int64_t offset, int64_t bytes, |
| 208 | int64_t *pnum, BdrvChild **file) |
Vladimir Sementsov-Ogievskiy | af5bcd7 | 2022-03-03 20:43:45 +0100 | [diff] [blame] | 209 | { |
| 210 | BDRVCopyBeforeWriteState *s = bs->opaque; |
| 211 | BlockReq *req = g_new(BlockReq, 1); |
| 212 | bool done; |
| 213 | |
| 214 | QEMU_LOCK_GUARD(&s->lock); |
| 215 | |
Vladimir Sementsov-Ogievskiy | f1bb39a | 2022-04-07 16:27:21 +0300 | [diff] [blame] | 216 | if (s->snapshot_error) { |
| 217 | g_free(req); |
| 218 | return NULL; |
| 219 | } |
| 220 | |
Vladimir Sementsov-Ogievskiy | af5bcd7 | 2022-03-03 20:43:45 +0100 | [diff] [blame] | 221 | if (bdrv_dirty_bitmap_next_zero(s->access_bitmap, offset, bytes) != -1) { |
| 222 | g_free(req); |
| 223 | return NULL; |
| 224 | } |
| 225 | |
| 226 | done = bdrv_dirty_bitmap_status(s->done_bitmap, offset, bytes, pnum); |
| 227 | if (done) { |
| 228 | /* |
| 229 | * Special invalid BlockReq, that is handled in |
| 230 | * cbw_snapshot_read_unlock(). We don't need to lock something to read |
| 231 | * from s->target. |
| 232 | */ |
| 233 | *req = (BlockReq) {.offset = -1, .bytes = -1}; |
| 234 | *file = s->target; |
| 235 | } else { |
| 236 | reqlist_init_req(&s->frozen_read_reqs, req, offset, bytes); |
| 237 | *file = bs->file; |
| 238 | } |
| 239 | |
| 240 | return req; |
| 241 | } |
| 242 | |
Paolo Bonzini | 3e61404 | 2022-09-22 10:49:13 +0200 | [diff] [blame] | 243 | static coroutine_fn void |
| 244 | cbw_snapshot_read_unlock(BlockDriverState *bs, BlockReq *req) |
Vladimir Sementsov-Ogievskiy | af5bcd7 | 2022-03-03 20:43:45 +0100 | [diff] [blame] | 245 | { |
| 246 | BDRVCopyBeforeWriteState *s = bs->opaque; |
| 247 | |
| 248 | if (req->offset == -1 && req->bytes == -1) { |
| 249 | g_free(req); |
| 250 | return; |
| 251 | } |
| 252 | |
| 253 | QEMU_LOCK_GUARD(&s->lock); |
| 254 | |
| 255 | reqlist_remove_req(req); |
| 256 | g_free(req); |
| 257 | } |
| 258 | |
Kevin Wolf | 7b9e8b2 | 2023-02-03 16:21:54 +0100 | [diff] [blame] | 259 | static int coroutine_fn GRAPH_RDLOCK |
Vladimir Sementsov-Ogievskiy | af5bcd7 | 2022-03-03 20:43:45 +0100 | [diff] [blame] | 260 | cbw_co_preadv_snapshot(BlockDriverState *bs, int64_t offset, int64_t bytes, |
| 261 | QEMUIOVector *qiov, size_t qiov_offset) |
| 262 | { |
| 263 | BlockReq *req; |
| 264 | BdrvChild *file; |
| 265 | int ret; |
| 266 | |
| 267 | /* TODO: upgrade to async loop using AioTask */ |
| 268 | while (bytes) { |
| 269 | int64_t cur_bytes; |
| 270 | |
| 271 | req = cbw_snapshot_read_lock(bs, offset, bytes, &cur_bytes, &file); |
| 272 | if (!req) { |
| 273 | return -EACCES; |
| 274 | } |
| 275 | |
| 276 | ret = bdrv_co_preadv_part(file, offset, cur_bytes, |
| 277 | qiov, qiov_offset, 0); |
| 278 | cbw_snapshot_read_unlock(bs, req); |
| 279 | if (ret < 0) { |
| 280 | return ret; |
| 281 | } |
| 282 | |
| 283 | bytes -= cur_bytes; |
| 284 | offset += cur_bytes; |
| 285 | qiov_offset += cur_bytes; |
| 286 | } |
| 287 | |
| 288 | return 0; |
| 289 | } |
| 290 | |
Kevin Wolf | 7b9e8b2 | 2023-02-03 16:21:54 +0100 | [diff] [blame] | 291 | static int coroutine_fn GRAPH_RDLOCK |
Vladimir Sementsov-Ogievskiy | af5bcd7 | 2022-03-03 20:43:45 +0100 | [diff] [blame] | 292 | cbw_co_snapshot_block_status(BlockDriverState *bs, |
| 293 | bool want_zero, int64_t offset, int64_t bytes, |
| 294 | int64_t *pnum, int64_t *map, |
| 295 | BlockDriverState **file) |
| 296 | { |
| 297 | BDRVCopyBeforeWriteState *s = bs->opaque; |
| 298 | BlockReq *req; |
| 299 | int ret; |
| 300 | int64_t cur_bytes; |
| 301 | BdrvChild *child; |
| 302 | |
| 303 | req = cbw_snapshot_read_lock(bs, offset, bytes, &cur_bytes, &child); |
| 304 | if (!req) { |
| 305 | return -EACCES; |
| 306 | } |
| 307 | |
| 308 | ret = bdrv_block_status(child->bs, offset, cur_bytes, pnum, map, file); |
| 309 | if (child == s->target) { |
| 310 | /* |
| 311 | * We refer to s->target only for areas that we've written to it. |
| 312 | * And we can not report unallocated blocks in s->target: this will |
| 313 | * break generic block-status-above logic, that will go to |
| 314 | * copy-before-write filtered child in this case. |
| 315 | */ |
| 316 | assert(ret & BDRV_BLOCK_ALLOCATED); |
| 317 | } |
| 318 | |
| 319 | cbw_snapshot_read_unlock(bs, req); |
| 320 | |
| 321 | return ret; |
| 322 | } |
| 323 | |
Emanuele Giuseppe Esposito | 9a5a1c6 | 2023-02-03 16:21:47 +0100 | [diff] [blame] | 324 | static int coroutine_fn GRAPH_RDLOCK |
| 325 | cbw_co_pdiscard_snapshot(BlockDriverState *bs, int64_t offset, int64_t bytes) |
Vladimir Sementsov-Ogievskiy | af5bcd7 | 2022-03-03 20:43:45 +0100 | [diff] [blame] | 326 | { |
| 327 | BDRVCopyBeforeWriteState *s = bs->opaque; |
| 328 | |
| 329 | WITH_QEMU_LOCK_GUARD(&s->lock) { |
| 330 | bdrv_reset_dirty_bitmap(s->access_bitmap, offset, bytes); |
| 331 | } |
| 332 | |
| 333 | block_copy_reset(s->bcs, offset, bytes); |
| 334 | |
| 335 | return bdrv_co_pdiscard(s->target, offset, bytes); |
| 336 | } |
| 337 | |
Vladimir Sementsov-Ogievskiy | d003e0a | 2021-08-24 11:38:27 +0300 | [diff] [blame] | 338 | static void cbw_refresh_filename(BlockDriverState *bs) |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 339 | { |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 340 | pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), |
Vladimir Sementsov-Ogievskiy | 3c1e632 | 2021-08-24 11:38:34 +0300 | [diff] [blame] | 341 | bs->file->bs->filename); |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 342 | } |
| 343 | |
Vladimir Sementsov-Ogievskiy | d003e0a | 2021-08-24 11:38:27 +0300 | [diff] [blame] | 344 | static void cbw_child_perm(BlockDriverState *bs, BdrvChild *c, |
| 345 | BdrvChildRole role, |
| 346 | BlockReopenQueue *reopen_queue, |
| 347 | uint64_t perm, uint64_t shared, |
| 348 | uint64_t *nperm, uint64_t *nshared) |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 349 | { |
Max Reitz | 25191e5 | 2020-05-13 13:05:33 +0200 | [diff] [blame] | 350 | if (!(role & BDRV_CHILD_FILTERED)) { |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 351 | /* |
| 352 | * Target child |
| 353 | * |
| 354 | * Share write to target (child_file), to not interfere |
| 355 | * with guest writes to its disk which may be in target backing chain. |
Kevin Wolf | 958a04b | 2020-04-30 16:27:54 +0200 | [diff] [blame] | 356 | * Can't resize during a backup block job because we check the size |
| 357 | * only upfront. |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 358 | */ |
Kevin Wolf | 958a04b | 2020-04-30 16:27:54 +0200 | [diff] [blame] | 359 | *nshared = BLK_PERM_ALL & ~BLK_PERM_RESIZE; |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 360 | *nperm = BLK_PERM_WRITE; |
| 361 | } else { |
| 362 | /* Source child */ |
Max Reitz | e5d8a40 | 2020-05-13 13:05:44 +0200 | [diff] [blame] | 363 | bdrv_default_perms(bs, c, role, reopen_queue, |
Max Reitz | 69dca43 | 2020-05-13 13:05:39 +0200 | [diff] [blame] | 364 | perm, shared, nperm, nshared); |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 365 | |
Vladimir Sementsov-Ogievskiy | 3860c02 | 2021-08-24 11:38:32 +0300 | [diff] [blame] | 366 | if (!QLIST_EMPTY(&bs->parents)) { |
| 367 | if (perm & BLK_PERM_WRITE) { |
| 368 | *nperm = *nperm | BLK_PERM_CONSISTENT_READ; |
| 369 | } |
| 370 | *nshared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE); |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 371 | } |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 372 | } |
| 373 | } |
| 374 | |
Vladimir Sementsov-Ogievskiy | 79ef0ce | 2022-04-07 16:27:20 +0300 | [diff] [blame] | 375 | static BlockdevOptions *cbw_parse_options(QDict *options, Error **errp) |
Vladimir Sementsov-Ogievskiy | 5f3a3cd | 2022-03-03 20:43:37 +0100 | [diff] [blame] | 376 | { |
Vladimir Sementsov-Ogievskiy | 79ef0ce | 2022-04-07 16:27:20 +0300 | [diff] [blame] | 377 | BlockdevOptions *opts = NULL; |
Vladimir Sementsov-Ogievskiy | 5f3a3cd | 2022-03-03 20:43:37 +0100 | [diff] [blame] | 378 | Visitor *v = NULL; |
Vladimir Sementsov-Ogievskiy | 5f3a3cd | 2022-03-03 20:43:37 +0100 | [diff] [blame] | 379 | |
Vladimir Sementsov-Ogievskiy | 79ef0ce | 2022-04-07 16:27:20 +0300 | [diff] [blame] | 380 | qdict_put_str(options, "driver", "copy-before-write"); |
Vladimir Sementsov-Ogievskiy | 5f3a3cd | 2022-03-03 20:43:37 +0100 | [diff] [blame] | 381 | |
Vladimir Sementsov-Ogievskiy | 79ef0ce | 2022-04-07 16:27:20 +0300 | [diff] [blame] | 382 | v = qobject_input_visitor_new_flat_confused(options, errp); |
Vladimir Sementsov-Ogievskiy | 5f3a3cd | 2022-03-03 20:43:37 +0100 | [diff] [blame] | 383 | if (!v) { |
| 384 | goto out; |
| 385 | } |
| 386 | |
Vladimir Sementsov-Ogievskiy | 79ef0ce | 2022-04-07 16:27:20 +0300 | [diff] [blame] | 387 | visit_type_BlockdevOptions(v, NULL, &opts, errp); |
| 388 | if (!opts) { |
Vladimir Sementsov-Ogievskiy | 5f3a3cd | 2022-03-03 20:43:37 +0100 | [diff] [blame] | 389 | goto out; |
| 390 | } |
| 391 | |
Vladimir Sementsov-Ogievskiy | 79ef0ce | 2022-04-07 16:27:20 +0300 | [diff] [blame] | 392 | /* |
| 393 | * Delete options which we are going to parse through BlockdevOptions |
| 394 | * object for original options. |
| 395 | */ |
| 396 | qdict_extract_subqdict(options, NULL, "bitmap"); |
Vladimir Sementsov-Ogievskiy | f1bb39a | 2022-04-07 16:27:21 +0300 | [diff] [blame] | 397 | qdict_del(options, "on-cbw-error"); |
Vladimir Sementsov-Ogievskiy | 6db7fd1 | 2022-04-07 16:27:25 +0300 | [diff] [blame] | 398 | qdict_del(options, "cbw-timeout"); |
Vladimir Sementsov-Ogievskiy | 5f3a3cd | 2022-03-03 20:43:37 +0100 | [diff] [blame] | 399 | |
| 400 | out: |
Vladimir Sementsov-Ogievskiy | 5f3a3cd | 2022-03-03 20:43:37 +0100 | [diff] [blame] | 401 | visit_free(v); |
Vladimir Sementsov-Ogievskiy | 79ef0ce | 2022-04-07 16:27:20 +0300 | [diff] [blame] | 402 | qdict_del(options, "driver"); |
Vladimir Sementsov-Ogievskiy | 5f3a3cd | 2022-03-03 20:43:37 +0100 | [diff] [blame] | 403 | |
Vladimir Sementsov-Ogievskiy | 79ef0ce | 2022-04-07 16:27:20 +0300 | [diff] [blame] | 404 | return opts; |
Vladimir Sementsov-Ogievskiy | 5f3a3cd | 2022-03-03 20:43:37 +0100 | [diff] [blame] | 405 | } |
| 406 | |
Vladimir Sementsov-Ogievskiy | 751cec7 | 2021-08-24 11:38:43 +0300 | [diff] [blame] | 407 | static int cbw_open(BlockDriverState *bs, QDict *options, int flags, |
| 408 | Error **errp) |
Vladimir Sementsov-Ogievskiy | 1f0cacb | 2021-08-24 11:38:36 +0300 | [diff] [blame] | 409 | { |
Vladimir Sementsov-Ogievskiy | fe7ea40 | 2021-08-24 11:38:37 +0300 | [diff] [blame] | 410 | BDRVCopyBeforeWriteState *s = bs->opaque; |
Vladimir Sementsov-Ogievskiy | 5f3a3cd | 2022-03-03 20:43:37 +0100 | [diff] [blame] | 411 | BdrvDirtyBitmap *bitmap = NULL; |
Vladimir Sementsov-Ogievskiy | af5bcd7 | 2022-03-03 20:43:45 +0100 | [diff] [blame] | 412 | int64_t cluster_size; |
Vladimir Sementsov-Ogievskiy | 79ef0ce | 2022-04-07 16:27:20 +0300 | [diff] [blame] | 413 | g_autoptr(BlockdevOptions) full_opts = NULL; |
| 414 | BlockdevOptionsCbw *opts; |
Kevin Wolf | 9102f2e | 2023-05-25 14:47:09 +0200 | [diff] [blame] | 415 | AioContext *ctx; |
Vladimir Sementsov-Ogievskiy | 8393078 | 2022-07-26 23:11:21 +0300 | [diff] [blame] | 416 | int ret; |
Vladimir Sementsov-Ogievskiy | 79ef0ce | 2022-04-07 16:27:20 +0300 | [diff] [blame] | 417 | |
| 418 | full_opts = cbw_parse_options(options, errp); |
| 419 | if (!full_opts) { |
| 420 | return -EINVAL; |
| 421 | } |
| 422 | assert(full_opts->driver == BLOCKDEV_DRIVER_COPY_BEFORE_WRITE); |
| 423 | opts = &full_opts->u.copy_before_write; |
Vladimir Sementsov-Ogievskiy | 1f0cacb | 2021-08-24 11:38:36 +0300 | [diff] [blame] | 424 | |
Vladimir Sementsov-Ogievskiy | 8393078 | 2022-07-26 23:11:21 +0300 | [diff] [blame] | 425 | ret = bdrv_open_file_child(NULL, options, "file", bs, errp); |
| 426 | if (ret < 0) { |
| 427 | return ret; |
Vladimir Sementsov-Ogievskiy | 1f0cacb | 2021-08-24 11:38:36 +0300 | [diff] [blame] | 428 | } |
| 429 | |
Vladimir Sementsov-Ogievskiy | f44fd73 | 2021-08-24 11:38:40 +0300 | [diff] [blame] | 430 | s->target = bdrv_open_child(NULL, options, "target", bs, &child_of_bds, |
| 431 | BDRV_CHILD_DATA, false, errp); |
| 432 | if (!s->target) { |
Vladimir Sementsov-Ogievskiy | 1f0cacb | 2021-08-24 11:38:36 +0300 | [diff] [blame] | 433 | return -EINVAL; |
| 434 | } |
| 435 | |
Kevin Wolf | 9102f2e | 2023-05-25 14:47:09 +0200 | [diff] [blame] | 436 | ctx = bdrv_get_aio_context(bs); |
| 437 | aio_context_acquire(ctx); |
| 438 | |
Markus Armbruster | 54fde4f | 2022-11-04 17:06:52 +0100 | [diff] [blame] | 439 | if (opts->bitmap) { |
Vladimir Sementsov-Ogievskiy | 79ef0ce | 2022-04-07 16:27:20 +0300 | [diff] [blame] | 440 | bitmap = block_dirty_bitmap_lookup(opts->bitmap->node, |
| 441 | opts->bitmap->name, NULL, errp); |
| 442 | if (!bitmap) { |
Kevin Wolf | 9102f2e | 2023-05-25 14:47:09 +0200 | [diff] [blame] | 443 | ret = -EINVAL; |
| 444 | goto out; |
Vladimir Sementsov-Ogievskiy | 79ef0ce | 2022-04-07 16:27:20 +0300 | [diff] [blame] | 445 | } |
Vladimir Sementsov-Ogievskiy | 5f3a3cd | 2022-03-03 20:43:37 +0100 | [diff] [blame] | 446 | } |
Vladimir Sementsov-Ogievskiy | f1bb39a | 2022-04-07 16:27:21 +0300 | [diff] [blame] | 447 | s->on_cbw_error = opts->has_on_cbw_error ? opts->on_cbw_error : |
| 448 | ON_CBW_ERROR_BREAK_GUEST_WRITE; |
Vladimir Sementsov-Ogievskiy | 6db7fd1 | 2022-04-07 16:27:25 +0300 | [diff] [blame] | 449 | s->cbw_timeout_ns = opts->has_cbw_timeout ? |
| 450 | opts->cbw_timeout * NANOSECONDS_PER_SECOND : 0; |
Vladimir Sementsov-Ogievskiy | 5f3a3cd | 2022-03-03 20:43:37 +0100 | [diff] [blame] | 451 | |
Vladimir Sementsov-Ogievskiy | 5a50742 | 2021-08-24 11:38:38 +0300 | [diff] [blame] | 452 | bs->total_sectors = bs->file->bs->total_sectors; |
| 453 | bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED | |
| 454 | (BDRV_REQ_FUA & bs->file->bs->supported_write_flags); |
| 455 | bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED | |
| 456 | ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK) & |
| 457 | bs->file->bs->supported_zero_flags); |
| 458 | |
Vladimir Sementsov-Ogievskiy | 5f3a3cd | 2022-03-03 20:43:37 +0100 | [diff] [blame] | 459 | s->bcs = block_copy_state_new(bs->file, s->target, bitmap, errp); |
Vladimir Sementsov-Ogievskiy | fe7ea40 | 2021-08-24 11:38:37 +0300 | [diff] [blame] | 460 | if (!s->bcs) { |
Vladimir Sementsov-Ogievskiy | 1f0cacb | 2021-08-24 11:38:36 +0300 | [diff] [blame] | 461 | error_prepend(errp, "Cannot create block-copy-state: "); |
Kevin Wolf | 9102f2e | 2023-05-25 14:47:09 +0200 | [diff] [blame] | 462 | ret = -EINVAL; |
| 463 | goto out; |
Vladimir Sementsov-Ogievskiy | 1f0cacb | 2021-08-24 11:38:36 +0300 | [diff] [blame] | 464 | } |
| 465 | |
Vladimir Sementsov-Ogievskiy | af5bcd7 | 2022-03-03 20:43:45 +0100 | [diff] [blame] | 466 | cluster_size = block_copy_cluster_size(s->bcs); |
| 467 | |
| 468 | s->done_bitmap = bdrv_create_dirty_bitmap(bs, cluster_size, NULL, errp); |
| 469 | if (!s->done_bitmap) { |
Kevin Wolf | 9102f2e | 2023-05-25 14:47:09 +0200 | [diff] [blame] | 470 | ret = -EINVAL; |
| 471 | goto out; |
Vladimir Sementsov-Ogievskiy | af5bcd7 | 2022-03-03 20:43:45 +0100 | [diff] [blame] | 472 | } |
| 473 | bdrv_disable_dirty_bitmap(s->done_bitmap); |
| 474 | |
| 475 | /* s->access_bitmap starts equal to bcs bitmap */ |
| 476 | s->access_bitmap = bdrv_create_dirty_bitmap(bs, cluster_size, NULL, errp); |
| 477 | if (!s->access_bitmap) { |
Kevin Wolf | 9102f2e | 2023-05-25 14:47:09 +0200 | [diff] [blame] | 478 | ret = -EINVAL; |
| 479 | goto out; |
Vladimir Sementsov-Ogievskiy | af5bcd7 | 2022-03-03 20:43:45 +0100 | [diff] [blame] | 480 | } |
| 481 | bdrv_disable_dirty_bitmap(s->access_bitmap); |
| 482 | bdrv_dirty_bitmap_merge_internal(s->access_bitmap, |
| 483 | block_copy_dirty_bitmap(s->bcs), NULL, |
| 484 | true); |
| 485 | |
| 486 | qemu_co_mutex_init(&s->lock); |
| 487 | QLIST_INIT(&s->frozen_read_reqs); |
| 488 | |
Kevin Wolf | 9102f2e | 2023-05-25 14:47:09 +0200 | [diff] [blame] | 489 | ret = 0; |
| 490 | out: |
| 491 | aio_context_release(ctx); |
| 492 | return ret; |
Vladimir Sementsov-Ogievskiy | 1f0cacb | 2021-08-24 11:38:36 +0300 | [diff] [blame] | 493 | } |
| 494 | |
Vladimir Sementsov-Ogievskiy | 751cec7 | 2021-08-24 11:38:43 +0300 | [diff] [blame] | 495 | static void cbw_close(BlockDriverState *bs) |
| 496 | { |
| 497 | BDRVCopyBeforeWriteState *s = bs->opaque; |
| 498 | |
Vladimir Sementsov-Ogievskiy | af5bcd7 | 2022-03-03 20:43:45 +0100 | [diff] [blame] | 499 | bdrv_release_dirty_bitmap(s->access_bitmap); |
| 500 | bdrv_release_dirty_bitmap(s->done_bitmap); |
| 501 | |
Vladimir Sementsov-Ogievskiy | 751cec7 | 2021-08-24 11:38:43 +0300 | [diff] [blame] | 502 | block_copy_state_free(s->bcs); |
| 503 | s->bcs = NULL; |
| 504 | } |
| 505 | |
Vladimir Sementsov-Ogievskiy | d003e0a | 2021-08-24 11:38:27 +0300 | [diff] [blame] | 506 | BlockDriver bdrv_cbw_filter = { |
| 507 | .format_name = "copy-before-write", |
| 508 | .instance_size = sizeof(BDRVCopyBeforeWriteState), |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 509 | |
Vladimir Sementsov-Ogievskiy | 751cec7 | 2021-08-24 11:38:43 +0300 | [diff] [blame] | 510 | .bdrv_open = cbw_open, |
| 511 | .bdrv_close = cbw_close, |
| 512 | |
Vladimir Sementsov-Ogievskiy | d003e0a | 2021-08-24 11:38:27 +0300 | [diff] [blame] | 513 | .bdrv_co_preadv = cbw_co_preadv, |
| 514 | .bdrv_co_pwritev = cbw_co_pwritev, |
| 515 | .bdrv_co_pwrite_zeroes = cbw_co_pwrite_zeroes, |
| 516 | .bdrv_co_pdiscard = cbw_co_pdiscard, |
| 517 | .bdrv_co_flush = cbw_co_flush, |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 518 | |
Vladimir Sementsov-Ogievskiy | af5bcd7 | 2022-03-03 20:43:45 +0100 | [diff] [blame] | 519 | .bdrv_co_preadv_snapshot = cbw_co_preadv_snapshot, |
| 520 | .bdrv_co_pdiscard_snapshot = cbw_co_pdiscard_snapshot, |
| 521 | .bdrv_co_snapshot_block_status = cbw_co_snapshot_block_status, |
| 522 | |
Vladimir Sementsov-Ogievskiy | d003e0a | 2021-08-24 11:38:27 +0300 | [diff] [blame] | 523 | .bdrv_refresh_filename = cbw_refresh_filename, |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 524 | |
Vladimir Sementsov-Ogievskiy | d003e0a | 2021-08-24 11:38:27 +0300 | [diff] [blame] | 525 | .bdrv_child_perm = cbw_child_perm, |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 526 | |
| 527 | .is_filter = true, |
| 528 | }; |
| 529 | |
Vladimir Sementsov-Ogievskiy | d003e0a | 2021-08-24 11:38:27 +0300 | [diff] [blame] | 530 | BlockDriverState *bdrv_cbw_append(BlockDriverState *source, |
| 531 | BlockDriverState *target, |
| 532 | const char *filter_node_name, |
Vladimir Sementsov-Ogievskiy | d003e0a | 2021-08-24 11:38:27 +0300 | [diff] [blame] | 533 | BlockCopyState **bcs, |
| 534 | Error **errp) |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 535 | { |
Vladimir Sementsov-Ogievskiy | d003e0a | 2021-08-24 11:38:27 +0300 | [diff] [blame] | 536 | BDRVCopyBeforeWriteState *state; |
Kevin Wolf | 958a04b | 2020-04-30 16:27:54 +0200 | [diff] [blame] | 537 | BlockDriverState *top; |
Vladimir Sementsov-Ogievskiy | f44fd73 | 2021-08-24 11:38:40 +0300 | [diff] [blame] | 538 | QDict *opts; |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 539 | |
Kevin Wolf | 958a04b | 2020-04-30 16:27:54 +0200 | [diff] [blame] | 540 | assert(source->total_sectors == target->total_sectors); |
Emanuele Giuseppe Esposito | 377cc15 | 2022-03-03 10:16:08 -0500 | [diff] [blame] | 541 | GLOBAL_STATE_CODE(); |
Kevin Wolf | 958a04b | 2020-04-30 16:27:54 +0200 | [diff] [blame] | 542 | |
Vladimir Sementsov-Ogievskiy | f44fd73 | 2021-08-24 11:38:40 +0300 | [diff] [blame] | 543 | opts = qdict_new(); |
Vladimir Sementsov-Ogievskiy | 751cec7 | 2021-08-24 11:38:43 +0300 | [diff] [blame] | 544 | qdict_put_str(opts, "driver", "copy-before-write"); |
| 545 | if (filter_node_name) { |
| 546 | qdict_put_str(opts, "node-name", filter_node_name); |
| 547 | } |
Vladimir Sementsov-Ogievskiy | f44fd73 | 2021-08-24 11:38:40 +0300 | [diff] [blame] | 548 | qdict_put_str(opts, "file", bdrv_get_node_name(source)); |
| 549 | qdict_put_str(opts, "target", bdrv_get_node_name(target)); |
| 550 | |
Vladimir Sementsov-Ogievskiy | 751cec7 | 2021-08-24 11:38:43 +0300 | [diff] [blame] | 551 | top = bdrv_insert_node(source, opts, BDRV_O_RDWR, errp); |
| 552 | if (!top) { |
| 553 | return NULL; |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 554 | } |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 555 | |
Vladimir Sementsov-Ogievskiy | 751cec7 | 2021-08-24 11:38:43 +0300 | [diff] [blame] | 556 | state = top->opaque; |
Vladimir Sementsov-Ogievskiy | 7ddbce2 | 2021-08-24 11:38:35 +0300 | [diff] [blame] | 557 | *bcs = state->bcs; |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 558 | |
| 559 | return top; |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 560 | } |
| 561 | |
Vladimir Sementsov-Ogievskiy | d003e0a | 2021-08-24 11:38:27 +0300 | [diff] [blame] | 562 | void bdrv_cbw_drop(BlockDriverState *bs) |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 563 | { |
Emanuele Giuseppe Esposito | 377cc15 | 2022-03-03 10:16:08 -0500 | [diff] [blame] | 564 | GLOBAL_STATE_CODE(); |
Vladimir Sementsov-Ogievskiy | b75d64b | 2021-04-28 18:17:52 +0300 | [diff] [blame] | 565 | bdrv_drop_filter(bs, &error_abort); |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 566 | bdrv_unref(bs); |
Vladimir Sementsov-Ogievskiy | 7df7868 | 2019-10-01 16:14:08 +0300 | [diff] [blame] | 567 | } |
Vladimir Sementsov-Ogievskiy | 751cec7 | 2021-08-24 11:38:43 +0300 | [diff] [blame] | 568 | |
| 569 | static void cbw_init(void) |
| 570 | { |
| 571 | bdrv_register(&bdrv_cbw_filter); |
| 572 | } |
| 573 | |
| 574 | block_init(cbw_init); |