Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 1 | /* |
| 2 | * preallocate filter driver |
| 3 | * |
| 4 | * The driver performs preallocate operation: it is injected above |
| 5 | * some node, and before each write over EOF it does additional preallocating |
| 6 | * write-zeroes request. |
| 7 | * |
| 8 | * Copyright (c) 2020 Virtuozzo International GmbH. |
| 9 | * |
| 10 | * Author: |
| 11 | * Sementsov-Ogievskiy Vladimir <vsementsov@virtuozzo.com> |
| 12 | * |
| 13 | * This program is free software; you can redistribute it and/or modify |
| 14 | * it under the terms of the GNU General Public License as published by |
| 15 | * the Free Software Foundation; either version 2 of the License, or |
| 16 | * (at your option) any later version. |
| 17 | * |
| 18 | * This program is distributed in the hope that it will be useful, |
| 19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 21 | * GNU General Public License for more details. |
| 22 | * |
| 23 | * You should have received a copy of the GNU General Public License |
| 24 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 25 | */ |
| 26 | |
| 27 | #include "qemu/osdep.h" |
| 28 | |
| 29 | #include "qapi/error.h" |
| 30 | #include "qemu/module.h" |
| 31 | #include "qemu/option.h" |
| 32 | #include "qemu/units.h" |
Markus Armbruster | e2c1c34 | 2022-12-21 14:35:49 +0100 | [diff] [blame] | 33 | #include "block/block-io.h" |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 34 | #include "block/block_int.h" |
| 35 | |
| 36 | |
| 37 | typedef struct PreallocateOpts { |
| 38 | int64_t prealloc_size; |
| 39 | int64_t prealloc_align; |
| 40 | } PreallocateOpts; |
| 41 | |
| 42 | typedef struct BDRVPreallocateState { |
| 43 | PreallocateOpts opts; |
| 44 | |
| 45 | /* |
| 46 | * Track real data end, to crop preallocation on close. If < 0 the status is |
| 47 | * unknown. |
| 48 | * |
| 49 | * @data_end is a maximum of file size on open (or when we get write/resize |
| 50 | * permissions) and all write request ends after it. So it's safe to |
| 51 | * truncate to data_end if it is valid. |
| 52 | */ |
| 53 | int64_t data_end; |
| 54 | |
| 55 | /* |
| 56 | * Start of trailing preallocated area which reads as zero. May be smaller |
| 57 | * than data_end, if user does over-EOF write zero operation. If < 0 the |
| 58 | * status is unknown. |
| 59 | * |
| 60 | * If both @zero_start and @file_end are valid, the region |
| 61 | * [@zero_start, @file_end) is known to be preallocated zeroes. If @file_end |
| 62 | * is not valid, @zero_start doesn't make much sense. |
| 63 | */ |
| 64 | int64_t zero_start; |
| 65 | |
| 66 | /* |
| 67 | * Real end of file. Actually the cache for bdrv_getlength(bs->file->bs), |
| 68 | * to avoid extra lseek() calls on each write operation. If < 0 the status |
| 69 | * is unknown. |
| 70 | */ |
| 71 | int64_t file_end; |
| 72 | |
| 73 | /* |
| 74 | * All three states @data_end, @zero_start and @file_end are guaranteed to |
| 75 | * be invalid (< 0) when we don't have both exclusive BLK_PERM_RESIZE and |
| 76 | * BLK_PERM_WRITE permissions on file child. |
| 77 | */ |
Kevin Wolf | edcce17 | 2023-09-11 11:46:02 +0200 | [diff] [blame] | 78 | |
| 79 | /* Gives up the resize permission on children when parents don't need it */ |
| 80 | QEMUBH *drop_resize_bh; |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 81 | } BDRVPreallocateState; |
| 82 | |
Kevin Wolf | edcce17 | 2023-09-11 11:46:02 +0200 | [diff] [blame] | 83 | static int preallocate_drop_resize(BlockDriverState *bs, Error **errp); |
| 84 | static void preallocate_drop_resize_bh(void *opaque); |
| 85 | |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 86 | #define PREALLOCATE_OPT_PREALLOC_ALIGN "prealloc-align" |
| 87 | #define PREALLOCATE_OPT_PREALLOC_SIZE "prealloc-size" |
| 88 | static QemuOptsList runtime_opts = { |
| 89 | .name = "preallocate", |
| 90 | .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head), |
| 91 | .desc = { |
| 92 | { |
| 93 | .name = PREALLOCATE_OPT_PREALLOC_ALIGN, |
| 94 | .type = QEMU_OPT_SIZE, |
| 95 | .help = "on preallocation, align file length to this number, " |
| 96 | "default 1M", |
| 97 | }, |
| 98 | { |
| 99 | .name = PREALLOCATE_OPT_PREALLOC_SIZE, |
| 100 | .type = QEMU_OPT_SIZE, |
| 101 | .help = "how much to preallocate, default 128M", |
| 102 | }, |
| 103 | { /* end of list */ } |
| 104 | }, |
| 105 | }; |
| 106 | |
| 107 | static bool preallocate_absorb_opts(PreallocateOpts *dest, QDict *options, |
| 108 | BlockDriverState *child_bs, Error **errp) |
| 109 | { |
| 110 | QemuOpts *opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort); |
| 111 | |
| 112 | if (!qemu_opts_absorb_qdict(opts, options, errp)) { |
| 113 | return false; |
| 114 | } |
| 115 | |
| 116 | dest->prealloc_align = |
| 117 | qemu_opt_get_size(opts, PREALLOCATE_OPT_PREALLOC_ALIGN, 1 * MiB); |
| 118 | dest->prealloc_size = |
| 119 | qemu_opt_get_size(opts, PREALLOCATE_OPT_PREALLOC_SIZE, 128 * MiB); |
| 120 | |
| 121 | qemu_opts_del(opts); |
| 122 | |
| 123 | if (!QEMU_IS_ALIGNED(dest->prealloc_align, BDRV_SECTOR_SIZE)) { |
| 124 | error_setg(errp, "prealloc-align parameter of preallocate filter " |
| 125 | "is not aligned to %llu", BDRV_SECTOR_SIZE); |
| 126 | return false; |
| 127 | } |
| 128 | |
| 129 | if (!QEMU_IS_ALIGNED(dest->prealloc_align, |
| 130 | child_bs->bl.request_alignment)) { |
| 131 | error_setg(errp, "prealloc-align parameter of preallocate filter " |
| 132 | "is not aligned to underlying node request alignment " |
| 133 | "(%" PRIi32 ")", child_bs->bl.request_alignment); |
| 134 | return false; |
| 135 | } |
| 136 | |
| 137 | return true; |
| 138 | } |
| 139 | |
| 140 | static int preallocate_open(BlockDriverState *bs, QDict *options, int flags, |
| 141 | Error **errp) |
| 142 | { |
| 143 | BDRVPreallocateState *s = bs->opaque; |
Vladimir Sementsov-Ogievskiy | 8393078 | 2022-07-26 23:11:21 +0300 | [diff] [blame] | 144 | int ret; |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 145 | |
Kevin Wolf | a4b740d | 2023-10-27 17:53:32 +0200 | [diff] [blame] | 146 | GLOBAL_STATE_CODE(); |
| 147 | |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 148 | /* |
| 149 | * s->data_end and friends should be initialized on permission update. |
| 150 | * For this to work, mark them invalid. |
| 151 | */ |
| 152 | s->file_end = s->zero_start = s->data_end = -EINVAL; |
Kevin Wolf | edcce17 | 2023-09-11 11:46:02 +0200 | [diff] [blame] | 153 | s->drop_resize_bh = qemu_bh_new(preallocate_drop_resize_bh, bs); |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 154 | |
Vladimir Sementsov-Ogievskiy | 8393078 | 2022-07-26 23:11:21 +0300 | [diff] [blame] | 155 | ret = bdrv_open_file_child(NULL, options, "file", bs, errp); |
| 156 | if (ret < 0) { |
| 157 | return ret; |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 158 | } |
| 159 | |
Kevin Wolf | a4b740d | 2023-10-27 17:53:32 +0200 | [diff] [blame] | 160 | GRAPH_RDLOCK_GUARD_MAINLOOP(); |
| 161 | |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 162 | if (!preallocate_absorb_opts(&s->opts, options, bs->file->bs, errp)) { |
| 163 | return -EINVAL; |
| 164 | } |
| 165 | |
| 166 | bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED | |
| 167 | (BDRV_REQ_FUA & bs->file->bs->supported_write_flags); |
| 168 | |
| 169 | bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED | |
| 170 | ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK) & |
| 171 | bs->file->bs->supported_zero_flags); |
| 172 | |
| 173 | return 0; |
| 174 | } |
| 175 | |
Kevin Wolf | 1f051dc | 2023-10-27 17:53:33 +0200 | [diff] [blame] | 176 | static int GRAPH_RDLOCK |
| 177 | preallocate_truncate_to_real_size(BlockDriverState *bs, Error **errp) |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 178 | { |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 179 | BDRVPreallocateState *s = bs->opaque; |
Kevin Wolf | 01e28f6 | 2023-09-11 11:46:01 +0200 | [diff] [blame] | 180 | int ret; |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 181 | |
| 182 | if (s->file_end < 0) { |
| 183 | s->file_end = bdrv_getlength(bs->file->bs); |
| 184 | if (s->file_end < 0) { |
Kevin Wolf | 01e28f6 | 2023-09-11 11:46:01 +0200 | [diff] [blame] | 185 | error_setg_errno(errp, -s->file_end, "Failed to get file length"); |
| 186 | return s->file_end; |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 187 | } |
| 188 | } |
| 189 | |
| 190 | if (s->data_end < s->file_end) { |
| 191 | ret = bdrv_truncate(bs->file, s->data_end, true, PREALLOC_MODE_OFF, 0, |
| 192 | NULL); |
Kevin Wolf | 01e28f6 | 2023-09-11 11:46:01 +0200 | [diff] [blame] | 193 | if (ret < 0) { |
| 194 | error_setg_errno(errp, -ret, "Failed to drop preallocation"); |
| 195 | s->file_end = ret; |
| 196 | return ret; |
| 197 | } |
| 198 | s->file_end = s->data_end; |
| 199 | } |
| 200 | |
| 201 | return 0; |
| 202 | } |
| 203 | |
| 204 | static void preallocate_close(BlockDriverState *bs) |
| 205 | { |
| 206 | BDRVPreallocateState *s = bs->opaque; |
| 207 | |
Kevin Wolf | 1f051dc | 2023-10-27 17:53:33 +0200 | [diff] [blame] | 208 | GLOBAL_STATE_CODE(); |
| 209 | GRAPH_RDLOCK_GUARD_MAINLOOP(); |
| 210 | |
Kevin Wolf | edcce17 | 2023-09-11 11:46:02 +0200 | [diff] [blame] | 211 | qemu_bh_cancel(s->drop_resize_bh); |
| 212 | qemu_bh_delete(s->drop_resize_bh); |
| 213 | |
Kevin Wolf | 01e28f6 | 2023-09-11 11:46:01 +0200 | [diff] [blame] | 214 | if (s->data_end >= 0) { |
| 215 | preallocate_truncate_to_real_size(bs, NULL); |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 216 | } |
| 217 | } |
| 218 | |
| 219 | |
| 220 | /* |
| 221 | * Handle reopen. |
| 222 | * |
| 223 | * We must implement reopen handlers, otherwise reopen just don't work. Handle |
| 224 | * new options and don't care about preallocation state, as it is handled in |
| 225 | * set/check permission handlers. |
| 226 | */ |
| 227 | |
| 228 | static int preallocate_reopen_prepare(BDRVReopenState *reopen_state, |
| 229 | BlockReopenQueue *queue, Error **errp) |
| 230 | { |
| 231 | PreallocateOpts *opts = g_new0(PreallocateOpts, 1); |
Kevin Wolf | edcce17 | 2023-09-11 11:46:02 +0200 | [diff] [blame] | 232 | int ret; |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 233 | |
Kevin Wolf | 1f051dc | 2023-10-27 17:53:33 +0200 | [diff] [blame] | 234 | GLOBAL_STATE_CODE(); |
| 235 | GRAPH_RDLOCK_GUARD_MAINLOOP(); |
| 236 | |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 237 | if (!preallocate_absorb_opts(opts, reopen_state->options, |
| 238 | reopen_state->bs->file->bs, errp)) { |
| 239 | g_free(opts); |
| 240 | return -EINVAL; |
| 241 | } |
| 242 | |
Kevin Wolf | edcce17 | 2023-09-11 11:46:02 +0200 | [diff] [blame] | 243 | /* |
| 244 | * Drop the preallocation already here if reopening read-only. The child |
| 245 | * might also be reopened read-only and then scheduling a BH during the |
| 246 | * permission update is too late. |
| 247 | */ |
| 248 | if ((reopen_state->flags & BDRV_O_RDWR) == 0) { |
| 249 | ret = preallocate_drop_resize(reopen_state->bs, errp); |
| 250 | if (ret < 0) { |
| 251 | g_free(opts); |
| 252 | return ret; |
| 253 | } |
| 254 | } |
| 255 | |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 256 | reopen_state->opaque = opts; |
| 257 | |
| 258 | return 0; |
| 259 | } |
| 260 | |
| 261 | static void preallocate_reopen_commit(BDRVReopenState *state) |
| 262 | { |
| 263 | BDRVPreallocateState *s = state->bs->opaque; |
| 264 | |
| 265 | s->opts = *(PreallocateOpts *)state->opaque; |
| 266 | |
| 267 | g_free(state->opaque); |
| 268 | state->opaque = NULL; |
| 269 | } |
| 270 | |
| 271 | static void preallocate_reopen_abort(BDRVReopenState *state) |
| 272 | { |
| 273 | g_free(state->opaque); |
| 274 | state->opaque = NULL; |
| 275 | } |
| 276 | |
Kevin Wolf | b9b10c3 | 2023-02-03 16:21:50 +0100 | [diff] [blame] | 277 | static int coroutine_fn GRAPH_RDLOCK |
| 278 | preallocate_co_preadv_part(BlockDriverState *bs, int64_t offset, int64_t bytes, |
| 279 | QEMUIOVector *qiov, size_t qiov_offset, |
| 280 | BdrvRequestFlags flags) |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 281 | { |
| 282 | return bdrv_co_preadv_part(bs->file, offset, bytes, qiov, qiov_offset, |
| 283 | flags); |
| 284 | } |
| 285 | |
Emanuele Giuseppe Esposito | 9a5a1c6 | 2023-02-03 16:21:47 +0100 | [diff] [blame] | 286 | static int coroutine_fn GRAPH_RDLOCK |
| 287 | preallocate_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes) |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 288 | { |
| 289 | return bdrv_co_pdiscard(bs->file, offset, bytes); |
| 290 | } |
| 291 | |
| 292 | static bool can_write_resize(uint64_t perm) |
| 293 | { |
| 294 | return (perm & BLK_PERM_WRITE) && (perm & BLK_PERM_RESIZE); |
| 295 | } |
| 296 | |
Kevin Wolf | 1f051dc | 2023-10-27 17:53:33 +0200 | [diff] [blame] | 297 | static bool GRAPH_RDLOCK has_prealloc_perms(BlockDriverState *bs) |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 298 | { |
| 299 | BDRVPreallocateState *s = bs->opaque; |
| 300 | |
| 301 | if (can_write_resize(bs->file->perm)) { |
| 302 | assert(!(bs->file->shared_perm & BLK_PERM_WRITE)); |
| 303 | assert(!(bs->file->shared_perm & BLK_PERM_RESIZE)); |
| 304 | return true; |
| 305 | } |
| 306 | |
| 307 | assert(s->data_end < 0); |
| 308 | assert(s->zero_start < 0); |
| 309 | assert(s->file_end < 0); |
| 310 | return false; |
| 311 | } |
| 312 | |
| 313 | /* |
| 314 | * Call on each write. Returns true if @want_merge_zero is true and the region |
| 315 | * [offset, offset + bytes) is zeroed (as a result of this call or earlier |
| 316 | * preallocation). |
| 317 | * |
| 318 | * want_merge_zero is used to merge write-zero request with preallocation in |
| 319 | * one bdrv_co_pwrite_zeroes() call. |
| 320 | */ |
Kevin Wolf | abaf8b7 | 2023-02-03 16:21:48 +0100 | [diff] [blame] | 321 | static bool coroutine_fn GRAPH_RDLOCK |
| 322 | handle_write(BlockDriverState *bs, int64_t offset, int64_t bytes, |
| 323 | bool want_merge_zero) |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 324 | { |
| 325 | BDRVPreallocateState *s = bs->opaque; |
| 326 | int64_t end = offset + bytes; |
| 327 | int64_t prealloc_start, prealloc_end; |
| 328 | int ret; |
Vladimir Sementsov-Ogievskiy | 45e62b4 | 2022-02-15 13:16:09 +0100 | [diff] [blame] | 329 | uint32_t file_align = bs->file->bs->bl.request_alignment; |
| 330 | uint32_t prealloc_align = MAX(s->opts.prealloc_align, file_align); |
| 331 | |
| 332 | assert(QEMU_IS_ALIGNED(prealloc_align, file_align)); |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 333 | |
| 334 | if (!has_prealloc_perms(bs)) { |
| 335 | /* We don't have state neither should try to recover it */ |
| 336 | return false; |
| 337 | } |
| 338 | |
| 339 | if (s->data_end < 0) { |
Emanuele Giuseppe Esposito | bd53086 | 2023-01-13 21:42:06 +0100 | [diff] [blame] | 340 | s->data_end = bdrv_co_getlength(bs->file->bs); |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 341 | if (s->data_end < 0) { |
| 342 | return false; |
| 343 | } |
| 344 | |
| 345 | if (s->file_end < 0) { |
| 346 | s->file_end = s->data_end; |
| 347 | } |
| 348 | } |
| 349 | |
| 350 | if (end <= s->data_end) { |
| 351 | return false; |
| 352 | } |
| 353 | |
| 354 | /* We have valid s->data_end, and request writes beyond it. */ |
| 355 | |
| 356 | s->data_end = end; |
| 357 | if (s->zero_start < 0 || !want_merge_zero) { |
| 358 | s->zero_start = end; |
| 359 | } |
| 360 | |
| 361 | if (s->file_end < 0) { |
Emanuele Giuseppe Esposito | bd53086 | 2023-01-13 21:42:06 +0100 | [diff] [blame] | 362 | s->file_end = bdrv_co_getlength(bs->file->bs); |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 363 | if (s->file_end < 0) { |
| 364 | return false; |
| 365 | } |
| 366 | } |
| 367 | |
| 368 | /* Now s->data_end, s->zero_start and s->file_end are valid. */ |
| 369 | |
| 370 | if (end <= s->file_end) { |
| 371 | /* No preallocation needed. */ |
| 372 | return want_merge_zero && offset >= s->zero_start; |
| 373 | } |
| 374 | |
| 375 | /* Now we want new preallocation, as request writes beyond s->file_end. */ |
| 376 | |
Vladimir Sementsov-Ogievskiy | 45e62b4 | 2022-02-15 13:16:09 +0100 | [diff] [blame] | 377 | prealloc_start = QEMU_ALIGN_UP( |
| 378 | want_merge_zero ? MIN(offset, s->file_end) : s->file_end, |
| 379 | file_align); |
| 380 | prealloc_end = QEMU_ALIGN_UP( |
| 381 | MAX(prealloc_start, end) + s->opts.prealloc_size, |
| 382 | prealloc_align); |
| 383 | |
| 384 | want_merge_zero = want_merge_zero && (prealloc_start <= offset); |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 385 | |
| 386 | ret = bdrv_co_pwrite_zeroes( |
| 387 | bs->file, prealloc_start, prealloc_end - prealloc_start, |
| 388 | BDRV_REQ_NO_FALLBACK | BDRV_REQ_SERIALISING | BDRV_REQ_NO_WAIT); |
| 389 | if (ret < 0) { |
| 390 | s->file_end = ret; |
| 391 | return false; |
| 392 | } |
| 393 | |
| 394 | s->file_end = prealloc_end; |
| 395 | return want_merge_zero; |
| 396 | } |
| 397 | |
Kevin Wolf | abaf8b7 | 2023-02-03 16:21:48 +0100 | [diff] [blame] | 398 | static int coroutine_fn GRAPH_RDLOCK |
| 399 | preallocate_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, |
| 400 | int64_t bytes, BdrvRequestFlags flags) |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 401 | { |
| 402 | bool want_merge_zero = |
| 403 | !(flags & ~(BDRV_REQ_ZERO_WRITE | BDRV_REQ_NO_FALLBACK)); |
| 404 | if (handle_write(bs, offset, bytes, want_merge_zero)) { |
| 405 | return 0; |
| 406 | } |
| 407 | |
| 408 | return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags); |
| 409 | } |
| 410 | |
Kevin Wolf | b9b10c3 | 2023-02-03 16:21:50 +0100 | [diff] [blame] | 411 | static int coroutine_fn GRAPH_RDLOCK |
| 412 | preallocate_co_pwritev_part(BlockDriverState *bs, int64_t offset, int64_t bytes, |
| 413 | QEMUIOVector *qiov, size_t qiov_offset, |
| 414 | BdrvRequestFlags flags) |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 415 | { |
| 416 | handle_write(bs, offset, bytes, false); |
| 417 | |
| 418 | return bdrv_co_pwritev_part(bs->file, offset, bytes, qiov, qiov_offset, |
| 419 | flags); |
| 420 | } |
| 421 | |
Kevin Wolf | c2b8e31 | 2023-02-03 16:21:42 +0100 | [diff] [blame] | 422 | static int coroutine_fn GRAPH_RDLOCK |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 423 | preallocate_co_truncate(BlockDriverState *bs, int64_t offset, |
| 424 | bool exact, PreallocMode prealloc, |
| 425 | BdrvRequestFlags flags, Error **errp) |
| 426 | { |
| 427 | ERRP_GUARD(); |
| 428 | BDRVPreallocateState *s = bs->opaque; |
| 429 | int ret; |
| 430 | |
| 431 | if (s->data_end >= 0 && offset > s->data_end) { |
| 432 | if (s->file_end < 0) { |
Emanuele Giuseppe Esposito | bd53086 | 2023-01-13 21:42:06 +0100 | [diff] [blame] | 433 | s->file_end = bdrv_co_getlength(bs->file->bs); |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 434 | if (s->file_end < 0) { |
| 435 | error_setg(errp, "failed to get file length"); |
| 436 | return s->file_end; |
| 437 | } |
| 438 | } |
| 439 | |
| 440 | if (prealloc == PREALLOC_MODE_FALLOC) { |
| 441 | /* |
| 442 | * If offset <= s->file_end, the task is already done, just |
| 443 | * update s->data_end, to move part of "filter preallocation" |
| 444 | * to "preallocation requested by user". |
| 445 | * Otherwise just proceed to preallocate missing part. |
| 446 | */ |
| 447 | if (offset <= s->file_end) { |
| 448 | s->data_end = offset; |
| 449 | return 0; |
| 450 | } |
| 451 | } else { |
| 452 | /* |
| 453 | * We have to drop our preallocation, to |
| 454 | * - avoid "Cannot use preallocation for shrinking files" in |
| 455 | * case of offset < file_end |
| 456 | * - give PREALLOC_MODE_OFF a chance to keep small disk |
| 457 | * usage |
| 458 | * - give PREALLOC_MODE_FULL a chance to actually write the |
| 459 | * whole region as user expects |
| 460 | */ |
| 461 | if (s->file_end > s->data_end) { |
| 462 | ret = bdrv_co_truncate(bs->file, s->data_end, true, |
| 463 | PREALLOC_MODE_OFF, 0, errp); |
| 464 | if (ret < 0) { |
| 465 | s->file_end = ret; |
| 466 | error_prepend(errp, "preallocate-filter: failed to drop " |
| 467 | "write-zero preallocation: "); |
| 468 | return ret; |
| 469 | } |
| 470 | s->file_end = s->data_end; |
| 471 | } |
| 472 | } |
| 473 | |
| 474 | s->data_end = offset; |
| 475 | } |
| 476 | |
| 477 | ret = bdrv_co_truncate(bs->file, offset, exact, prealloc, flags, errp); |
| 478 | if (ret < 0) { |
| 479 | s->file_end = s->zero_start = s->data_end = ret; |
| 480 | return ret; |
| 481 | } |
| 482 | |
| 483 | if (has_prealloc_perms(bs)) { |
| 484 | s->file_end = s->zero_start = s->data_end = offset; |
| 485 | } |
| 486 | return 0; |
| 487 | } |
| 488 | |
Emanuele Giuseppe Esposito | 8809534 | 2023-02-03 16:21:46 +0100 | [diff] [blame] | 489 | static int coroutine_fn GRAPH_RDLOCK preallocate_co_flush(BlockDriverState *bs) |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 490 | { |
| 491 | return bdrv_co_flush(bs->file->bs); |
| 492 | } |
| 493 | |
Kevin Wolf | 8ab8140 | 2023-02-03 16:22:02 +0100 | [diff] [blame] | 494 | static int64_t coroutine_fn GRAPH_RDLOCK |
| 495 | preallocate_co_getlength(BlockDriverState *bs) |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 496 | { |
| 497 | int64_t ret; |
| 498 | BDRVPreallocateState *s = bs->opaque; |
| 499 | |
| 500 | if (s->data_end >= 0) { |
| 501 | return s->data_end; |
| 502 | } |
| 503 | |
Emanuele Giuseppe Esposito | c86422c | 2023-01-13 21:42:04 +0100 | [diff] [blame] | 504 | ret = bdrv_co_getlength(bs->file->bs); |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 505 | |
| 506 | if (has_prealloc_perms(bs)) { |
| 507 | s->file_end = s->zero_start = s->data_end = ret; |
| 508 | } |
| 509 | |
| 510 | return ret; |
| 511 | } |
| 512 | |
Kevin Wolf | 1f051dc | 2023-10-27 17:53:33 +0200 | [diff] [blame] | 513 | static int GRAPH_RDLOCK |
| 514 | preallocate_drop_resize(BlockDriverState *bs, Error **errp) |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 515 | { |
| 516 | BDRVPreallocateState *s = bs->opaque; |
Kevin Wolf | edcce17 | 2023-09-11 11:46:02 +0200 | [diff] [blame] | 517 | int ret; |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 518 | |
Kevin Wolf | edcce17 | 2023-09-11 11:46:02 +0200 | [diff] [blame] | 519 | if (s->data_end < 0) { |
| 520 | return 0; |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 521 | } |
| 522 | |
Kevin Wolf | edcce17 | 2023-09-11 11:46:02 +0200 | [diff] [blame] | 523 | /* |
| 524 | * Before switching children to be read-only, truncate them to remove |
| 525 | * the preallocation and let them have the real size. |
| 526 | */ |
| 527 | ret = preallocate_truncate_to_real_size(bs, errp); |
| 528 | if (ret < 0) { |
| 529 | return ret; |
| 530 | } |
| 531 | |
| 532 | /* |
| 533 | * We'll drop our permissions and will allow other users to take write and |
| 534 | * resize permissions (see preallocate_child_perm). Anyone will be able to |
| 535 | * change the child, so mark all states invalid. We'll regain control if a |
| 536 | * parent requests write access again. |
| 537 | */ |
| 538 | s->data_end = s->file_end = s->zero_start = -EINVAL; |
| 539 | |
Kevin Wolf | edcce17 | 2023-09-11 11:46:02 +0200 | [diff] [blame] | 540 | bdrv_child_refresh_perms(bs, bs->file, NULL); |
Kevin Wolf | edcce17 | 2023-09-11 11:46:02 +0200 | [diff] [blame] | 541 | |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 542 | return 0; |
| 543 | } |
| 544 | |
Kevin Wolf | edcce17 | 2023-09-11 11:46:02 +0200 | [diff] [blame] | 545 | static void preallocate_drop_resize_bh(void *opaque) |
| 546 | { |
Kevin Wolf | 1f051dc | 2023-10-27 17:53:33 +0200 | [diff] [blame] | 547 | GLOBAL_STATE_CODE(); |
| 548 | GRAPH_RDLOCK_GUARD_MAINLOOP(); |
| 549 | |
Kevin Wolf | edcce17 | 2023-09-11 11:46:02 +0200 | [diff] [blame] | 550 | /* |
| 551 | * In case of errors, we'll simply keep the exclusive lock on the image |
| 552 | * indefinitely. |
| 553 | */ |
| 554 | preallocate_drop_resize(opaque, NULL); |
| 555 | } |
| 556 | |
Kevin Wolf | 79a5586 | 2023-10-27 17:53:29 +0200 | [diff] [blame] | 557 | static void GRAPH_RDLOCK |
| 558 | preallocate_set_perm(BlockDriverState *bs, uint64_t perm, uint64_t shared) |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 559 | { |
| 560 | BDRVPreallocateState *s = bs->opaque; |
| 561 | |
| 562 | if (can_write_resize(perm)) { |
Kevin Wolf | edcce17 | 2023-09-11 11:46:02 +0200 | [diff] [blame] | 563 | qemu_bh_cancel(s->drop_resize_bh); |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 564 | if (s->data_end < 0) { |
| 565 | s->data_end = s->file_end = s->zero_start = |
Kevin Wolf | edcce17 | 2023-09-11 11:46:02 +0200 | [diff] [blame] | 566 | bs->file->bs->total_sectors * BDRV_SECTOR_SIZE; |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 567 | } |
| 568 | } else { |
Kevin Wolf | edcce17 | 2023-09-11 11:46:02 +0200 | [diff] [blame] | 569 | qemu_bh_schedule(s->drop_resize_bh); |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 570 | } |
| 571 | } |
| 572 | |
| 573 | static void preallocate_child_perm(BlockDriverState *bs, BdrvChild *c, |
| 574 | BdrvChildRole role, BlockReopenQueue *reopen_queue, |
| 575 | uint64_t perm, uint64_t shared, uint64_t *nperm, uint64_t *nshared) |
| 576 | { |
Kevin Wolf | edcce17 | 2023-09-11 11:46:02 +0200 | [diff] [blame] | 577 | BDRVPreallocateState *s = bs->opaque; |
| 578 | |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 579 | bdrv_default_perms(bs, c, role, reopen_queue, perm, shared, nperm, nshared); |
| 580 | |
Kevin Wolf | edcce17 | 2023-09-11 11:46:02 +0200 | [diff] [blame] | 581 | /* |
| 582 | * We need exclusive write and resize permissions on the child not only when |
| 583 | * the parent can write to it, but also after the parent gave up write |
| 584 | * permissions until preallocate_drop_resize() has completed. |
| 585 | */ |
| 586 | if (can_write_resize(perm) || s->data_end != -EINVAL) { |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 587 | *nperm |= BLK_PERM_WRITE | BLK_PERM_RESIZE; |
| 588 | |
| 589 | /* |
| 590 | * Don't share, to keep our states s->file_end, s->data_end and |
| 591 | * s->zero_start valid. |
| 592 | */ |
| 593 | *nshared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE); |
| 594 | } |
| 595 | } |
| 596 | |
Kevin Wolf | 9ea473f | 2023-09-05 15:06:07 +0200 | [diff] [blame] | 597 | static BlockDriver bdrv_preallocate_filter = { |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 598 | .format_name = "preallocate", |
| 599 | .instance_size = sizeof(BDRVPreallocateState), |
| 600 | |
Emanuele Giuseppe Esposito | c86422c | 2023-01-13 21:42:04 +0100 | [diff] [blame] | 601 | .bdrv_co_getlength = preallocate_co_getlength, |
| 602 | .bdrv_open = preallocate_open, |
| 603 | .bdrv_close = preallocate_close, |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 604 | |
| 605 | .bdrv_reopen_prepare = preallocate_reopen_prepare, |
| 606 | .bdrv_reopen_commit = preallocate_reopen_commit, |
| 607 | .bdrv_reopen_abort = preallocate_reopen_abort, |
| 608 | |
| 609 | .bdrv_co_preadv_part = preallocate_co_preadv_part, |
| 610 | .bdrv_co_pwritev_part = preallocate_co_pwritev_part, |
| 611 | .bdrv_co_pwrite_zeroes = preallocate_co_pwrite_zeroes, |
| 612 | .bdrv_co_pdiscard = preallocate_co_pdiscard, |
| 613 | .bdrv_co_flush = preallocate_co_flush, |
| 614 | .bdrv_co_truncate = preallocate_co_truncate, |
| 615 | |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 616 | .bdrv_set_perm = preallocate_set_perm, |
| 617 | .bdrv_child_perm = preallocate_child_perm, |
| 618 | |
Vladimir Sementsov-Ogievskiy | 33fa222 | 2020-10-21 17:58:46 +0300 | [diff] [blame] | 619 | .is_filter = true, |
| 620 | }; |
| 621 | |
| 622 | static void bdrv_preallocate_init(void) |
| 623 | { |
| 624 | bdrv_register(&bdrv_preallocate_filter); |
| 625 | } |
| 626 | |
| 627 | block_init(bdrv_preallocate_init); |