1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2016-present, Facebook, Inc. 4 * All rights reserved. 5 * 6 */ 7 8 #include <linux/bio.h> 9 #include <linux/bitmap.h> 10 #include <linux/err.h> 11 #include <linux/init.h> 12 #include <linux/kernel.h> 13 #include <linux/mm.h> 14 #include <linux/sched/mm.h> 15 #include <linux/pagemap.h> 16 #include <linux/refcount.h> 17 #include <linux/sched.h> 18 #include <linux/slab.h> 19 #include <linux/zstd.h> 20 #include "misc.h" 21 #include "fs.h" 22 #include "btrfs_inode.h" 23 #include "compression.h" 24 #include "super.h" 25 26 #define ZSTD_BTRFS_MAX_WINDOWLOG 17 27 #define ZSTD_BTRFS_MAX_INPUT (1U << ZSTD_BTRFS_MAX_WINDOWLOG) 28 #define ZSTD_BTRFS_DEFAULT_LEVEL 3 29 #define ZSTD_BTRFS_MIN_LEVEL -15 30 #define ZSTD_BTRFS_MAX_LEVEL 15 31 /* 307s to avoid pathologically clashing with transaction commit */ 32 #define ZSTD_BTRFS_RECLAIM_JIFFIES (307 * HZ) 33 34 static zstd_parameters zstd_get_btrfs_parameters(int level, 35 size_t src_len) 36 { 37 zstd_parameters params = zstd_get_params(level, src_len); 38 39 if (params.cParams.windowLog > ZSTD_BTRFS_MAX_WINDOWLOG) 40 params.cParams.windowLog = ZSTD_BTRFS_MAX_WINDOWLOG; 41 WARN_ON(src_len > ZSTD_BTRFS_MAX_INPUT); 42 return params; 43 } 44 45 struct workspace { 46 void *mem; 47 size_t size; 48 char *buf; 49 int level; 50 int req_level; 51 unsigned long last_used; /* jiffies */ 52 struct list_head list; 53 struct list_head lru_list; 54 zstd_in_buffer in_buf; 55 zstd_out_buffer out_buf; 56 zstd_parameters params; 57 }; 58 59 /* 60 * Zstd Workspace Management 61 * 62 * Zstd workspaces have different memory requirements depending on the level. 63 * The zstd workspaces are managed by having individual lists for each level 64 * and a global lru. Forward progress is maintained by protecting a max level 65 * workspace. 66 * 67 * Getting a workspace is done by using the bitmap to identify the levels that 68 * have available workspaces and scans up. This lets us recycle higher level 69 * workspaces because of the monotonic memory guarantee. A workspace's 70 * last_used is only updated if it is being used by the corresponding memory 71 * level. Putting a workspace involves adding it back to the appropriate places 72 * and adding it back to the lru if necessary. 73 * 74 * A timer is used to reclaim workspaces if they have not been used for 75 * ZSTD_BTRFS_RECLAIM_JIFFIES. This helps keep only active workspaces around. 76 * The upper bound is provided by the workqueue limit which is 2 (percpu limit). 77 */ 78 79 struct zstd_workspace_manager { 80 const struct btrfs_compress_op *ops; 81 spinlock_t lock; 82 struct list_head lru_list; 83 struct list_head idle_ws[ZSTD_BTRFS_MAX_LEVEL]; 84 unsigned long active_map; 85 wait_queue_head_t wait; 86 struct timer_list timer; 87 }; 88 89 static struct zstd_workspace_manager wsm; 90 91 static size_t zstd_ws_mem_sizes[ZSTD_BTRFS_MAX_LEVEL]; 92 93 static inline struct workspace *list_to_workspace(struct list_head *list) 94 { 95 return container_of(list, struct workspace, list); 96 } 97 98 static inline int clip_level(int level) 99 { 100 return max(0, level - 1); 101 } 102 103 /* 104 * Timer callback to free unused workspaces. 105 * 106 * @t: timer 107 * 108 * This scans the lru_list and attempts to reclaim any workspace that hasn't 109 * been used for ZSTD_BTRFS_RECLAIM_JIFFIES. 110 * 111 * The context is softirq and does not need the _bh locking primitives. 112 */ 113 static void zstd_reclaim_timer_fn(struct timer_list *timer) 114 { 115 unsigned long reclaim_threshold = jiffies - ZSTD_BTRFS_RECLAIM_JIFFIES; 116 struct list_head *pos, *next; 117 118 ASSERT(timer == &wsm.timer); 119 120 spin_lock(&wsm.lock); 121 122 if (list_empty(&wsm.lru_list)) { 123 spin_unlock(&wsm.lock); 124 return; 125 } 126 127 list_for_each_prev_safe(pos, next, &wsm.lru_list) { 128 struct workspace *victim = container_of(pos, struct workspace, 129 lru_list); 130 int level; 131 132 if (time_after(victim->last_used, reclaim_threshold)) 133 break; 134 135 /* workspace is in use */ 136 if (victim->req_level) 137 continue; 138 139 level = victim->level; 140 list_del(&victim->lru_list); 141 list_del(&victim->list); 142 zstd_free_workspace(&victim->list); 143 144 if (list_empty(&wsm.idle_ws[level])) 145 clear_bit(level, &wsm.active_map); 146 147 } 148 149 if (!list_empty(&wsm.lru_list)) 150 mod_timer(&wsm.timer, jiffies + ZSTD_BTRFS_RECLAIM_JIFFIES); 151 152 spin_unlock(&wsm.lock); 153 } 154 155 /* 156 * Calculate monotonic memory bounds. 157 * 158 * It is possible based on the level configurations that a higher level 159 * workspace uses less memory than a lower level workspace. In order to reuse 160 * workspaces, this must be made a monotonic relationship. This precomputes 161 * the required memory for each level and enforces the monotonicity between 162 * level and memory required. 163 */ 164 static void zstd_calc_ws_mem_sizes(void) 165 { 166 size_t max_size = 0; 167 int level; 168 169 for (level = ZSTD_BTRFS_MIN_LEVEL; level <= ZSTD_BTRFS_MAX_LEVEL; level++) { 170 if (level == 0) 171 continue; 172 zstd_parameters params = 173 zstd_get_btrfs_parameters(level, ZSTD_BTRFS_MAX_INPUT); 174 size_t level_size = 175 max_t(size_t, 176 zstd_cstream_workspace_bound(¶ms.cParams), 177 zstd_dstream_workspace_bound(ZSTD_BTRFS_MAX_INPUT)); 178 179 max_size = max_t(size_t, max_size, level_size); 180 /* Use level 1 workspace size for all the fast mode negative levels. */ 181 zstd_ws_mem_sizes[clip_level(level)] = max_size; 182 } 183 } 184 185 void zstd_init_workspace_manager(void) 186 { 187 struct list_head *ws; 188 int i; 189 190 zstd_calc_ws_mem_sizes(); 191 192 wsm.ops = &btrfs_zstd_compress; 193 spin_lock_init(&wsm.lock); 194 init_waitqueue_head(&wsm.wait); 195 timer_setup(&wsm.timer, zstd_reclaim_timer_fn, 0); 196 197 INIT_LIST_HEAD(&wsm.lru_list); 198 for (i = 0; i < ZSTD_BTRFS_MAX_LEVEL; i++) 199 INIT_LIST_HEAD(&wsm.idle_ws[i]); 200 201 ws = zstd_alloc_workspace(ZSTD_BTRFS_MAX_LEVEL); 202 if (IS_ERR(ws)) { 203 btrfs_warn(NULL, "cannot preallocate zstd compression workspace"); 204 } else { 205 set_bit(ZSTD_BTRFS_MAX_LEVEL - 1, &wsm.active_map); 206 list_add(ws, &wsm.idle_ws[ZSTD_BTRFS_MAX_LEVEL - 1]); 207 } 208 } 209 210 void zstd_cleanup_workspace_manager(void) 211 { 212 struct workspace *workspace; 213 int i; 214 215 spin_lock_bh(&wsm.lock); 216 for (i = 0; i < ZSTD_BTRFS_MAX_LEVEL; i++) { 217 while (!list_empty(&wsm.idle_ws[i])) { 218 workspace = container_of(wsm.idle_ws[i].next, 219 struct workspace, list); 220 list_del(&workspace->list); 221 list_del(&workspace->lru_list); 222 zstd_free_workspace(&workspace->list); 223 } 224 } 225 spin_unlock_bh(&wsm.lock); 226 227 timer_delete_sync(&wsm.timer); 228 } 229 230 /* 231 * Find workspace for given level. 232 * 233 * @level: compression level 234 * 235 * This iterates over the set bits in the active_map beginning at the requested 236 * compression level. This lets us utilize already allocated workspaces before 237 * allocating a new one. If the workspace is of a larger size, it is used, but 238 * the place in the lru_list and last_used times are not updated. This is to 239 * offer the opportunity to reclaim the workspace in favor of allocating an 240 * appropriately sized one in the future. 241 */ 242 static struct list_head *zstd_find_workspace(int level) 243 { 244 struct list_head *ws; 245 struct workspace *workspace; 246 int i = clip_level(level); 247 248 spin_lock_bh(&wsm.lock); 249 for_each_set_bit_from(i, &wsm.active_map, ZSTD_BTRFS_MAX_LEVEL) { 250 if (!list_empty(&wsm.idle_ws[i])) { 251 ws = wsm.idle_ws[i].next; 252 workspace = list_to_workspace(ws); 253 list_del_init(ws); 254 /* keep its place if it's a lower level using this */ 255 workspace->req_level = level; 256 if (clip_level(level) == workspace->level) 257 list_del(&workspace->lru_list); 258 if (list_empty(&wsm.idle_ws[i])) 259 clear_bit(i, &wsm.active_map); 260 spin_unlock_bh(&wsm.lock); 261 return ws; 262 } 263 } 264 spin_unlock_bh(&wsm.lock); 265 266 return NULL; 267 } 268 269 /* 270 * Zstd get_workspace for level. 271 * 272 * @level: compression level 273 * 274 * If @level is 0, then any compression level can be used. Therefore, we begin 275 * scanning from 1. We first scan through possible workspaces and then after 276 * attempt to allocate a new workspace. If we fail to allocate one due to 277 * memory pressure, go to sleep waiting for the max level workspace to free up. 278 */ 279 struct list_head *zstd_get_workspace(int level) 280 { 281 struct list_head *ws; 282 unsigned int nofs_flag; 283 284 /* level == 0 means we can use any workspace */ 285 if (!level) 286 level = 1; 287 288 again: 289 ws = zstd_find_workspace(level); 290 if (ws) 291 return ws; 292 293 nofs_flag = memalloc_nofs_save(); 294 ws = zstd_alloc_workspace(level); 295 memalloc_nofs_restore(nofs_flag); 296 297 if (IS_ERR(ws)) { 298 DEFINE_WAIT(wait); 299 300 prepare_to_wait(&wsm.wait, &wait, TASK_UNINTERRUPTIBLE); 301 schedule(); 302 finish_wait(&wsm.wait, &wait); 303 304 goto again; 305 } 306 307 return ws; 308 } 309 310 /* 311 * Zstd put_workspace. 312 * 313 * @ws: list_head for the workspace 314 * 315 * When putting back a workspace, we only need to update the LRU if we are of 316 * the requested compression level. Here is where we continue to protect the 317 * max level workspace or update last_used accordingly. If the reclaim timer 318 * isn't set, it is also set here. Only the max level workspace tries and wakes 319 * up waiting workspaces. 320 */ 321 void zstd_put_workspace(struct list_head *ws) 322 { 323 struct workspace *workspace = list_to_workspace(ws); 324 325 spin_lock_bh(&wsm.lock); 326 327 /* A node is only taken off the lru if we are the corresponding level */ 328 if (clip_level(workspace->req_level) == workspace->level) { 329 /* Hide a max level workspace from reclaim */ 330 if (list_empty(&wsm.idle_ws[ZSTD_BTRFS_MAX_LEVEL - 1])) { 331 INIT_LIST_HEAD(&workspace->lru_list); 332 } else { 333 workspace->last_used = jiffies; 334 list_add(&workspace->lru_list, &wsm.lru_list); 335 if (!timer_pending(&wsm.timer)) 336 mod_timer(&wsm.timer, 337 jiffies + ZSTD_BTRFS_RECLAIM_JIFFIES); 338 } 339 } 340 341 set_bit(workspace->level, &wsm.active_map); 342 list_add(&workspace->list, &wsm.idle_ws[workspace->level]); 343 workspace->req_level = 0; 344 345 spin_unlock_bh(&wsm.lock); 346 347 if (workspace->level == clip_level(ZSTD_BTRFS_MAX_LEVEL)) 348 cond_wake_up(&wsm.wait); 349 } 350 351 void zstd_free_workspace(struct list_head *ws) 352 { 353 struct workspace *workspace = list_entry(ws, struct workspace, list); 354 355 kvfree(workspace->mem); 356 kfree(workspace->buf); 357 kfree(workspace); 358 } 359 360 struct list_head *zstd_alloc_workspace(int level) 361 { 362 struct workspace *workspace; 363 364 workspace = kzalloc(sizeof(*workspace), GFP_KERNEL); 365 if (!workspace) 366 return ERR_PTR(-ENOMEM); 367 368 /* Use level 1 workspace size for all the fast mode negative levels. */ 369 workspace->size = zstd_ws_mem_sizes[clip_level(level)]; 370 workspace->level = clip_level(level); 371 workspace->req_level = level; 372 workspace->last_used = jiffies; 373 workspace->mem = kvmalloc(workspace->size, GFP_KERNEL | __GFP_NOWARN); 374 workspace->buf = kmalloc(PAGE_SIZE, GFP_KERNEL); 375 if (!workspace->mem || !workspace->buf) 376 goto fail; 377 378 INIT_LIST_HEAD(&workspace->list); 379 INIT_LIST_HEAD(&workspace->lru_list); 380 381 return &workspace->list; 382 fail: 383 zstd_free_workspace(&workspace->list); 384 return ERR_PTR(-ENOMEM); 385 } 386 387 int zstd_compress_folios(struct list_head *ws, struct address_space *mapping, 388 u64 start, struct folio **folios, unsigned long *out_folios, 389 unsigned long *total_in, unsigned long *total_out) 390 { 391 struct workspace *workspace = list_entry(ws, struct workspace, list); 392 zstd_cstream *stream; 393 int ret = 0; 394 int nr_folios = 0; 395 struct folio *in_folio = NULL; /* The current folio to read. */ 396 struct folio *out_folio = NULL; /* The current folio to write to. */ 397 unsigned long tot_in = 0; 398 unsigned long tot_out = 0; 399 unsigned long len = *total_out; 400 const unsigned long nr_dest_folios = *out_folios; 401 const u64 orig_end = start + len; 402 unsigned long max_out = nr_dest_folios * PAGE_SIZE; 403 unsigned int cur_len; 404 405 workspace->params = zstd_get_btrfs_parameters(workspace->req_level, len); 406 *out_folios = 0; 407 *total_out = 0; 408 *total_in = 0; 409 410 /* Initialize the stream */ 411 stream = zstd_init_cstream(&workspace->params, len, workspace->mem, 412 workspace->size); 413 if (unlikely(!stream)) { 414 struct btrfs_inode *inode = BTRFS_I(mapping->host); 415 416 btrfs_err(inode->root->fs_info, 417 "zstd compression init level %d failed, root %llu inode %llu offset %llu", 418 workspace->req_level, btrfs_root_id(inode->root), 419 btrfs_ino(inode), start); 420 ret = -EIO; 421 goto out; 422 } 423 424 /* map in the first page of input data */ 425 ret = btrfs_compress_filemap_get_folio(mapping, start, &in_folio); 426 if (ret < 0) 427 goto out; 428 cur_len = btrfs_calc_input_length(in_folio, orig_end, start); 429 workspace->in_buf.src = kmap_local_folio(in_folio, offset_in_folio(in_folio, start)); 430 workspace->in_buf.pos = 0; 431 workspace->in_buf.size = cur_len; 432 433 /* Allocate and map in the output buffer */ 434 out_folio = btrfs_alloc_compr_folio(); 435 if (out_folio == NULL) { 436 ret = -ENOMEM; 437 goto out; 438 } 439 folios[nr_folios++] = out_folio; 440 workspace->out_buf.dst = folio_address(out_folio); 441 workspace->out_buf.pos = 0; 442 workspace->out_buf.size = min_t(size_t, max_out, PAGE_SIZE); 443 444 while (1) { 445 size_t ret2; 446 447 ret2 = zstd_compress_stream(stream, &workspace->out_buf, 448 &workspace->in_buf); 449 if (unlikely(zstd_is_error(ret2))) { 450 struct btrfs_inode *inode = BTRFS_I(mapping->host); 451 452 btrfs_warn(inode->root->fs_info, 453 "zstd compression level %d failed, error %d root %llu inode %llu offset %llu", 454 workspace->req_level, zstd_get_error_code(ret2), 455 btrfs_root_id(inode->root), btrfs_ino(inode), 456 start); 457 ret = -EIO; 458 goto out; 459 } 460 461 /* Check to see if we are making it bigger */ 462 if (tot_in + workspace->in_buf.pos > 8192 && 463 tot_in + workspace->in_buf.pos < 464 tot_out + workspace->out_buf.pos) { 465 ret = -E2BIG; 466 goto out; 467 } 468 469 /* We've reached the end of our output range */ 470 if (workspace->out_buf.pos >= max_out) { 471 tot_out += workspace->out_buf.pos; 472 ret = -E2BIG; 473 goto out; 474 } 475 476 /* Check if we need more output space */ 477 if (workspace->out_buf.pos == workspace->out_buf.size) { 478 tot_out += PAGE_SIZE; 479 max_out -= PAGE_SIZE; 480 if (nr_folios == nr_dest_folios) { 481 ret = -E2BIG; 482 goto out; 483 } 484 out_folio = btrfs_alloc_compr_folio(); 485 if (out_folio == NULL) { 486 ret = -ENOMEM; 487 goto out; 488 } 489 folios[nr_folios++] = out_folio; 490 workspace->out_buf.dst = folio_address(out_folio); 491 workspace->out_buf.pos = 0; 492 workspace->out_buf.size = min_t(size_t, max_out, 493 PAGE_SIZE); 494 } 495 496 /* We've reached the end of the input */ 497 if (workspace->in_buf.pos >= len) { 498 tot_in += workspace->in_buf.pos; 499 break; 500 } 501 502 /* Check if we need more input */ 503 if (workspace->in_buf.pos == workspace->in_buf.size) { 504 tot_in += workspace->in_buf.size; 505 kunmap_local(workspace->in_buf.src); 506 workspace->in_buf.src = NULL; 507 folio_put(in_folio); 508 start += cur_len; 509 len -= cur_len; 510 ret = btrfs_compress_filemap_get_folio(mapping, start, &in_folio); 511 if (ret < 0) 512 goto out; 513 cur_len = btrfs_calc_input_length(in_folio, orig_end, start); 514 workspace->in_buf.src = kmap_local_folio(in_folio, 515 offset_in_folio(in_folio, start)); 516 workspace->in_buf.pos = 0; 517 workspace->in_buf.size = cur_len; 518 } 519 } 520 while (1) { 521 size_t ret2; 522 523 ret2 = zstd_end_stream(stream, &workspace->out_buf); 524 if (unlikely(zstd_is_error(ret2))) { 525 struct btrfs_inode *inode = BTRFS_I(mapping->host); 526 527 btrfs_err(inode->root->fs_info, 528 "zstd compression end level %d failed, error %d root %llu inode %llu offset %llu", 529 workspace->req_level, zstd_get_error_code(ret2), 530 btrfs_root_id(inode->root), btrfs_ino(inode), 531 start); 532 ret = -EIO; 533 goto out; 534 } 535 if (ret2 == 0) { 536 tot_out += workspace->out_buf.pos; 537 break; 538 } 539 if (workspace->out_buf.pos >= max_out) { 540 tot_out += workspace->out_buf.pos; 541 ret = -E2BIG; 542 goto out; 543 } 544 545 tot_out += PAGE_SIZE; 546 max_out -= PAGE_SIZE; 547 if (nr_folios == nr_dest_folios) { 548 ret = -E2BIG; 549 goto out; 550 } 551 out_folio = btrfs_alloc_compr_folio(); 552 if (out_folio == NULL) { 553 ret = -ENOMEM; 554 goto out; 555 } 556 folios[nr_folios++] = out_folio; 557 workspace->out_buf.dst = folio_address(out_folio); 558 workspace->out_buf.pos = 0; 559 workspace->out_buf.size = min_t(size_t, max_out, PAGE_SIZE); 560 } 561 562 if (tot_out >= tot_in) { 563 ret = -E2BIG; 564 goto out; 565 } 566 567 ret = 0; 568 *total_in = tot_in; 569 *total_out = tot_out; 570 out: 571 *out_folios = nr_folios; 572 if (workspace->in_buf.src) { 573 kunmap_local(workspace->in_buf.src); 574 folio_put(in_folio); 575 } 576 return ret; 577 } 578 579 int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb) 580 { 581 struct workspace *workspace = list_entry(ws, struct workspace, list); 582 struct folio **folios_in = cb->compressed_folios; 583 size_t srclen = cb->compressed_len; 584 zstd_dstream *stream; 585 int ret = 0; 586 unsigned long folio_in_index = 0; 587 unsigned long total_folios_in = DIV_ROUND_UP(srclen, PAGE_SIZE); 588 unsigned long buf_start; 589 unsigned long total_out = 0; 590 591 stream = zstd_init_dstream( 592 ZSTD_BTRFS_MAX_INPUT, workspace->mem, workspace->size); 593 if (unlikely(!stream)) { 594 struct btrfs_inode *inode = cb->bbio.inode; 595 596 btrfs_err(inode->root->fs_info, 597 "zstd decompression init failed, root %llu inode %llu offset %llu", 598 btrfs_root_id(inode->root), btrfs_ino(inode), cb->start); 599 ret = -EIO; 600 goto done; 601 } 602 603 workspace->in_buf.src = kmap_local_folio(folios_in[folio_in_index], 0); 604 workspace->in_buf.pos = 0; 605 workspace->in_buf.size = min_t(size_t, srclen, PAGE_SIZE); 606 607 workspace->out_buf.dst = workspace->buf; 608 workspace->out_buf.pos = 0; 609 workspace->out_buf.size = PAGE_SIZE; 610 611 while (1) { 612 size_t ret2; 613 614 ret2 = zstd_decompress_stream(stream, &workspace->out_buf, 615 &workspace->in_buf); 616 if (unlikely(zstd_is_error(ret2))) { 617 struct btrfs_inode *inode = cb->bbio.inode; 618 619 btrfs_err(inode->root->fs_info, 620 "zstd decompression failed, error %d root %llu inode %llu offset %llu", 621 zstd_get_error_code(ret2), btrfs_root_id(inode->root), 622 btrfs_ino(inode), cb->start); 623 ret = -EIO; 624 goto done; 625 } 626 buf_start = total_out; 627 total_out += workspace->out_buf.pos; 628 workspace->out_buf.pos = 0; 629 630 ret = btrfs_decompress_buf2page(workspace->out_buf.dst, 631 total_out - buf_start, cb, buf_start); 632 if (ret == 0) 633 break; 634 635 if (workspace->in_buf.pos >= srclen) 636 break; 637 638 /* Check if we've hit the end of a frame */ 639 if (ret2 == 0) 640 break; 641 642 if (workspace->in_buf.pos == workspace->in_buf.size) { 643 kunmap_local(workspace->in_buf.src); 644 folio_in_index++; 645 if (folio_in_index >= total_folios_in) { 646 workspace->in_buf.src = NULL; 647 ret = -EIO; 648 goto done; 649 } 650 srclen -= PAGE_SIZE; 651 workspace->in_buf.src = 652 kmap_local_folio(folios_in[folio_in_index], 0); 653 workspace->in_buf.pos = 0; 654 workspace->in_buf.size = min_t(size_t, srclen, PAGE_SIZE); 655 } 656 } 657 ret = 0; 658 done: 659 if (workspace->in_buf.src) 660 kunmap_local(workspace->in_buf.src); 661 return ret; 662 } 663 664 int zstd_decompress(struct list_head *ws, const u8 *data_in, 665 struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen, 666 size_t destlen) 667 { 668 struct workspace *workspace = list_entry(ws, struct workspace, list); 669 struct btrfs_fs_info *fs_info = btrfs_sb(folio_inode(dest_folio)->i_sb); 670 const u32 sectorsize = fs_info->sectorsize; 671 zstd_dstream *stream; 672 int ret = 0; 673 unsigned long to_copy = 0; 674 675 stream = zstd_init_dstream( 676 ZSTD_BTRFS_MAX_INPUT, workspace->mem, workspace->size); 677 if (unlikely(!stream)) { 678 struct btrfs_inode *inode = folio_to_inode(dest_folio); 679 680 btrfs_err(inode->root->fs_info, 681 "zstd decompression init failed, root %llu inode %llu offset %llu", 682 btrfs_root_id(inode->root), btrfs_ino(inode), 683 folio_pos(dest_folio)); 684 ret = -EIO; 685 goto finish; 686 } 687 688 workspace->in_buf.src = data_in; 689 workspace->in_buf.pos = 0; 690 workspace->in_buf.size = srclen; 691 692 workspace->out_buf.dst = workspace->buf; 693 workspace->out_buf.pos = 0; 694 workspace->out_buf.size = sectorsize; 695 696 /* 697 * Since both input and output buffers should not exceed one sector, 698 * one call should end the decompression. 699 */ 700 ret = zstd_decompress_stream(stream, &workspace->out_buf, &workspace->in_buf); 701 if (unlikely(zstd_is_error(ret))) { 702 struct btrfs_inode *inode = folio_to_inode(dest_folio); 703 704 btrfs_err(inode->root->fs_info, 705 "zstd decompression failed, error %d root %llu inode %llu offset %llu", 706 zstd_get_error_code(ret), btrfs_root_id(inode->root), 707 btrfs_ino(inode), folio_pos(dest_folio)); 708 goto finish; 709 } 710 to_copy = workspace->out_buf.pos; 711 memcpy_to_folio(dest_folio, dest_pgoff, workspace->out_buf.dst, to_copy); 712 finish: 713 /* Error or early end. */ 714 if (unlikely(to_copy < destlen)) { 715 ret = -EIO; 716 folio_zero_range(dest_folio, dest_pgoff + to_copy, destlen - to_copy); 717 } 718 return ret; 719 } 720 721 const struct btrfs_compress_op btrfs_zstd_compress = { 722 /* ZSTD uses own workspace manager */ 723 .workspace_manager = NULL, 724 .min_level = ZSTD_BTRFS_MIN_LEVEL, 725 .max_level = ZSTD_BTRFS_MAX_LEVEL, 726 .default_level = ZSTD_BTRFS_DEFAULT_LEVEL, 727 }; 728