drivers/lightnvm/pblk-read.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2016 CNEX Labs
   4  * Initial release: Javier Gonzalez <javier@cnexlabs.com>
   5  *                  Matias Bjorling <matias@cnexlabs.com>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License version
   9  * 2 as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * pblk-read.c - pblk's read path
  17  */
  18
  19 #include "pblk.h"
  20
  21 /*
  22  * There is no guarantee that the value read from cache has not been updated and
  23  * resides at another location in the cache. We guarantee though that if the
  24  * value is read from the cache, it belongs to the mapped lba. In order to
  25  * guarantee and order between writes and reads are ordered, a flush must be
  26  * issued.
  27  */
  28 static int pblk_read_from_cache(struct pblk *pblk, struct bio *bio,
  29                                 sector_t lba, struct ppa_addr ppa,
  30                                 int bio_iter, bool advanced_bio)
  31 {
  32 #ifdef CONFIG_NVM_PBLK_DEBUG
  33         /* Callers must ensure that the ppa points to a cache address */
  34         BUG_ON(pblk_ppa_empty(ppa));
  35         BUG_ON(!pblk_addr_in_cache(ppa));
  36 #endif
  37
  38         return pblk_rb_copy_to_bio(&pblk->rwb, bio, lba, ppa,
  39                                                 bio_iter, advanced_bio);
  40 }
  41
  42 static void pblk_read_ppalist_rq(struct pblk *pblk, struct nvm_rq *rqd,
  43                                  struct bio *bio, sector_t blba,
  44                                  unsigned long *read_bitmap)
  45 {
  46         struct pblk_sec_meta *meta_list = rqd->meta_list;
  47         struct ppa_addr ppas[NVM_MAX_VLBA];
  48         int nr_secs = rqd->nr_ppas;
  49         bool advanced_bio = false;
  50         int i, j = 0;
  51
  52         pblk_lookup_l2p_seq(pblk, ppas, blba, nr_secs);
  53
  54         for (i = 0; i < nr_secs; i++) {
  55                 struct ppa_addr p = ppas[i];
  56                 sector_t lba = blba + i;
  57
  58 retry:
  59                 if (pblk_ppa_empty(p)) {
  60                         WARN_ON(test_and_set_bit(i, read_bitmap));
  61                         meta_list[i].lba = cpu_to_le64(ADDR_EMPTY);
  62
  63                         if (unlikely(!advanced_bio)) {
  64                                 bio_advance(bio, (i) * PBLK_EXPOSED_PAGE_SIZE);
  65                                 advanced_bio = true;
  66                         }
  67
  68                         goto next;
  69                 }
  70
  71                 /* Try to read from write buffer. The address is later checked
  72                  * on the write buffer to prevent retrieving overwritten data.
  73                  */
  74                 if (pblk_addr_in_cache(p)) {
  75                         if (!pblk_read_from_cache(pblk, bio, lba, p, i,
  76                                                                 advanced_bio)) {
  77                                 pblk_lookup_l2p_seq(pblk, &p, lba, 1);
  78                                 goto retry;
  79                         }
  80                         WARN_ON(test_and_set_bit(i, read_bitmap));
  81                         meta_list[i].lba = cpu_to_le64(lba);
  82                         advanced_bio = true;
  83 #ifdef CONFIG_NVM_PBLK_DEBUG
  84                         atomic_long_inc(&pblk->cache_reads);
  85 #endif
  86                 } else {
  87                         /* Read from media non-cached sectors */
  88                         rqd->ppa_list[j++] = p;
  89                 }
  90
  91 next:
  92                 if (advanced_bio)
  93                         bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
  94         }
  95
  96         if (pblk_io_aligned(pblk, nr_secs))
  97                 rqd->is_seq = 1;
  98
  99 #ifdef CONFIG_NVM_PBLK_DEBUG
 100         atomic_long_add(nr_secs, &pblk->inflight_reads);
 101 #endif
 102 }
 103
 104
 105 static void pblk_read_check_seq(struct pblk *pblk, struct nvm_rq *rqd,
 106                                 sector_t blba)
 107 {
 108         struct pblk_sec_meta *meta_lba_list = rqd->meta_list;
 109         int nr_lbas = rqd->nr_ppas;
 110         int i;
 111
 112         for (i = 0; i < nr_lbas; i++) {
 113                 u64 lba = le64_to_cpu(meta_lba_list[i].lba);
 114
 115                 if (lba == ADDR_EMPTY)
 116                         continue;
 117
 118                 if (lba != blba + i) {
 119 #ifdef CONFIG_NVM_PBLK_DEBUG
 120                         struct ppa_addr *ppa_list = nvm_rq_to_ppa_list(rqd);
 121
 122                         print_ppa(pblk, &ppa_list[i], "seq", i);
 123 #endif
 124                         pblk_err(pblk, "corrupted read LBA (%llu/%llu)\n",
 125                                                         lba, (u64)blba + i);
 126                         WARN_ON(1);
 127                 }
 128         }
 129 }
 130
 131 /*
 132  * There can be holes in the lba list.
 133  */
 134 static void pblk_read_check_rand(struct pblk *pblk, struct nvm_rq *rqd,
 135                                  u64 *lba_list, int nr_lbas)
 136 {
 137         struct pblk_sec_meta *meta_lba_list = rqd->meta_list;
 138         int i, j;
 139
 140         for (i = 0, j = 0; i < nr_lbas; i++) {
 141                 u64 lba = lba_list[i];
 142                 u64 meta_lba;
 143
 144                 if (lba == ADDR_EMPTY)
 145                         continue;
 146
 147                 meta_lba = le64_to_cpu(meta_lba_list[j].lba);
 148
 149                 if (lba != meta_lba) {
 150 #ifdef CONFIG_NVM_PBLK_DEBUG
 151                         struct ppa_addr *ppa_list = nvm_rq_to_ppa_list(rqd);
 152
 153                         print_ppa(pblk, &ppa_list[j], "rnd", j);
 154 #endif
 155                         pblk_err(pblk, "corrupted read LBA (%llu/%llu)\n",
 156                                                         meta_lba, lba);
 157                         WARN_ON(1);
 158                 }
 159
 160                 j++;
 161         }
 162
 163         WARN_ONCE(j != rqd->nr_ppas, "pblk: corrupted random request\n");
 164 }
 165
 166 static void pblk_end_user_read(struct bio *bio)
 167 {
 168 #ifdef CONFIG_NVM_PBLK_DEBUG
 169         WARN_ONCE(bio->bi_status, "pblk: corrupted read bio\n");
 170 #endif
 171         bio_endio(bio);
 172 }
 173
 174 static void __pblk_end_io_read(struct pblk *pblk, struct nvm_rq *rqd,
 175                                bool put_line)
 176 {
 177         struct nvm_tgt_dev *dev = pblk->dev;
 178         struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd);
 179         struct bio *int_bio = rqd->bio;
 180         unsigned long start_time = r_ctx->start_time;
 181
 182         generic_end_io_acct(dev->q, REQ_OP_READ, &pblk->disk->part0, start_time);
 183
 184         if (rqd->error)
 185                 pblk_log_read_err(pblk, rqd);
 186
 187         pblk_read_check_seq(pblk, rqd, r_ctx->lba);
 188
 189         if (int_bio)
 190                 bio_put(int_bio);
 191
 192         if (put_line)
 193                 pblk_rq_to_line_put(pblk, rqd);
 194
 195 #ifdef CONFIG_NVM_PBLK_DEBUG
 196         atomic_long_add(rqd->nr_ppas, &pblk->sync_reads);
 197         atomic_long_sub(rqd->nr_ppas, &pblk->inflight_reads);
 198 #endif
 199
 200         pblk_free_rqd(pblk, rqd, PBLK_READ);
 201         atomic_dec(&pblk->inflight_io);
 202 }
 203
 204 static void pblk_end_io_read(struct nvm_rq *rqd)
 205 {
 206         struct pblk *pblk = rqd->private;
 207         struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd);
 208         struct bio *bio = (struct bio *)r_ctx->private;
 209
 210         pblk_end_user_read(bio);
 211         __pblk_end_io_read(pblk, rqd, true);
 212 }
 213
 214 static void pblk_end_partial_read(struct nvm_rq *rqd)
 215 {
 216         struct pblk *pblk = rqd->private;
 217         struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd);
 218         struct pblk_pr_ctx *pr_ctx = r_ctx->private;
 219         struct bio *new_bio = rqd->bio;
 220         struct bio *bio = pr_ctx->orig_bio;
 221         struct bio_vec src_bv, dst_bv;
 222         struct pblk_sec_meta *meta_list = rqd->meta_list;
 223         int bio_init_idx = pr_ctx->bio_init_idx;
 224         unsigned long *read_bitmap = pr_ctx->bitmap;
 225         int nr_secs = pr_ctx->orig_nr_secs;
 226         int nr_holes = nr_secs - bitmap_weight(read_bitmap, nr_secs);
 227         void *src_p, *dst_p;
 228         int hole, i;
 229
 230         if (unlikely(nr_holes == 1)) {
 231                 struct ppa_addr ppa;
 232
 233                 ppa = rqd->ppa_addr;
 234                 rqd->ppa_list = pr_ctx->ppa_ptr;
 235                 rqd->dma_ppa_list = pr_ctx->dma_ppa_list;
 236                 rqd->ppa_list[0] = ppa;
 237         }
 238
 239         for (i = 0; i < nr_secs; i++) {
 240                 pr_ctx->lba_list_media[i] = meta_list[i].lba;
 241                 meta_list[i].lba = pr_ctx->lba_list_mem[i];
 242         }
 243
 244         /* Fill the holes in the original bio */
 245         i = 0;
 246         hole = find_first_zero_bit(read_bitmap, nr_secs);
 247         do {
 248                 struct pblk_line *line;
 249
 250                 line = pblk_ppa_to_line(pblk, rqd->ppa_list[i]);
 251                 kref_put(&line->ref, pblk_line_put);
 252
 253                 meta_list[hole].lba = pr_ctx->lba_list_media[i];
 254
 255                 src_bv = new_bio->bi_io_vec[i++];
 256                 dst_bv = bio->bi_io_vec[bio_init_idx + hole];
 257
 258                 src_p = kmap_atomic(src_bv.bv_page);
 259                 dst_p = kmap_atomic(dst_bv.bv_page);
 260
 261                 memcpy(dst_p + dst_bv.bv_offset,
 262                         src_p + src_bv.bv_offset,
 263                         PBLK_EXPOSED_PAGE_SIZE);
 264
 265                 kunmap_atomic(src_p);
 266                 kunmap_atomic(dst_p);
 267
 268                 mempool_free(src_bv.bv_page, &pblk->page_bio_pool);
 269
 270                 hole = find_next_zero_bit(read_bitmap, nr_secs, hole + 1);
 271         } while (hole < nr_secs);
 272
 273         bio_put(new_bio);
 274         kfree(pr_ctx);
 275
 276         /* restore original request */
 277         rqd->bio = NULL;
 278         rqd->nr_ppas = nr_secs;
 279
 280         bio_endio(bio);
 281         __pblk_end_io_read(pblk, rqd, false);
 282 }
 283
 284 static int pblk_setup_partial_read(struct pblk *pblk, struct nvm_rq *rqd,
 285                             unsigned int bio_init_idx,
 286                             unsigned long *read_bitmap,
 287                             int nr_holes)
 288 {
 289         struct pblk_sec_meta *meta_list = rqd->meta_list;
 290         struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd);
 291         struct pblk_pr_ctx *pr_ctx;
 292         struct bio *new_bio, *bio = r_ctx->private;
 293         int nr_secs = rqd->nr_ppas;
 294         int i;
 295
 296         new_bio = bio_alloc(GFP_KERNEL, nr_holes);
 297
 298         if (pblk_bio_add_pages(pblk, new_bio, GFP_KERNEL, nr_holes))
 299                 goto fail_bio_put;
 300
 301         if (nr_holes != new_bio->bi_vcnt) {
 302                 WARN_ONCE(1, "pblk: malformed bio\n");
 303                 goto fail_free_pages;
 304         }
 305
 306         pr_ctx = kzalloc(sizeof(struct pblk_pr_ctx), GFP_KERNEL);
 307         if (!pr_ctx)
 308                 goto fail_free_pages;
 309
 310         for (i = 0; i < nr_secs; i++)
 311                 pr_ctx->lba_list_mem[i] = meta_list[i].lba;
 312
 313         new_bio->bi_iter.bi_sector = 0; /* internal bio */
 314         bio_set_op_attrs(new_bio, REQ_OP_READ, 0);
 315
 316         rqd->bio = new_bio;
 317         rqd->nr_ppas = nr_holes;
 318
 319         pr_ctx->orig_bio = bio;
 320         bitmap_copy(pr_ctx->bitmap, read_bitmap, NVM_MAX_VLBA);
 321         pr_ctx->bio_init_idx = bio_init_idx;
 322         pr_ctx->orig_nr_secs = nr_secs;
 323         r_ctx->private = pr_ctx;
 324
 325         if (unlikely(nr_holes == 1)) {
 326                 pr_ctx->ppa_ptr = rqd->ppa_list;
 327                 pr_ctx->dma_ppa_list = rqd->dma_ppa_list;
 328                 rqd->ppa_addr = rqd->ppa_list[0];
 329         }
 330         return 0;
 331
 332 fail_free_pages:
 333         pblk_bio_free_pages(pblk, new_bio, 0, new_bio->bi_vcnt);
 334 fail_bio_put:
 335         bio_put(new_bio);
 336
 337         return -ENOMEM;
 338 }
 339
 340 static int pblk_partial_read_bio(struct pblk *pblk, struct nvm_rq *rqd,
 341                                  unsigned int bio_init_idx,
 342                                  unsigned long *read_bitmap, int nr_secs)
 343 {
 344         int nr_holes;
 345         int ret;
 346
 347         nr_holes = nr_secs - bitmap_weight(read_bitmap, nr_secs);
 348
 349         if (pblk_setup_partial_read(pblk, rqd, bio_init_idx, read_bitmap,
 350                                     nr_holes))
 351                 return NVM_IO_ERR;
 352
 353         rqd->end_io = pblk_end_partial_read;
 354
 355         ret = pblk_submit_io(pblk, rqd);
 356         if (ret) {
 357                 bio_put(rqd->bio);
 358                 pblk_err(pblk, "partial read IO submission failed\n");
 359                 goto err;
 360         }
 361
 362         return NVM_IO_OK;
 363
 364 err:
 365         pblk_err(pblk, "failed to perform partial read\n");
 366
 367         /* Free allocated pages in new bio */
 368         pblk_bio_free_pages(pblk, rqd->bio, 0, rqd->bio->bi_vcnt);
 369         __pblk_end_io_read(pblk, rqd, false);
 370         return NVM_IO_ERR;
 371 }
 372
 373 static void pblk_read_rq(struct pblk *pblk, struct nvm_rq *rqd, struct bio *bio,
 374                          sector_t lba, unsigned long *read_bitmap)
 375 {
 376         struct pblk_sec_meta *meta_list = rqd->meta_list;
 377         struct ppa_addr ppa;
 378
 379         pblk_lookup_l2p_seq(pblk, &ppa, lba, 1);
 380
 381 #ifdef CONFIG_NVM_PBLK_DEBUG
 382         atomic_long_inc(&pblk->inflight_reads);
 383 #endif
 384
 385 retry:
 386         if (pblk_ppa_empty(ppa)) {
 387                 WARN_ON(test_and_set_bit(0, read_bitmap));
 388                 meta_list[0].lba = cpu_to_le64(ADDR_EMPTY);
 389                 return;
 390         }
 391
 392         /* Try to read from write buffer. The address is later checked on the
 393          * write buffer to prevent retrieving overwritten data.
 394          */
 395         if (pblk_addr_in_cache(ppa)) {
 396                 if (!pblk_read_from_cache(pblk, bio, lba, ppa, 0, 1)) {
 397                         pblk_lookup_l2p_seq(pblk, &ppa, lba, 1);
 398                         goto retry;
 399                 }
 400
 401                 WARN_ON(test_and_set_bit(0, read_bitmap));
 402                 meta_list[0].lba = cpu_to_le64(lba);
 403
 404 #ifdef CONFIG_NVM_PBLK_DEBUG
 405                 atomic_long_inc(&pblk->cache_reads);
 406 #endif
 407         } else {
 408                 rqd->ppa_addr = ppa;
 409         }
 410 }
 411
 412 int pblk_submit_read(struct pblk *pblk, struct bio *bio)
 413 {
 414         struct nvm_tgt_dev *dev = pblk->dev;
 415         struct request_queue *q = dev->q;
 416         sector_t blba = pblk_get_lba(bio);
 417         unsigned int nr_secs = pblk_get_secs(bio);
 418         struct pblk_g_ctx *r_ctx;
 419         struct nvm_rq *rqd;
 420         unsigned int bio_init_idx;
 421         DECLARE_BITMAP(read_bitmap, NVM_MAX_VLBA);
 422         int ret = NVM_IO_ERR;
 423
 424         generic_start_io_acct(q, REQ_OP_READ, bio_sectors(bio),
 425                               &pblk->disk->part0);
 426
 427         bitmap_zero(read_bitmap, nr_secs);
 428
 429         rqd = pblk_alloc_rqd(pblk, PBLK_READ);
 430
 431         rqd->opcode = NVM_OP_PREAD;
 432         rqd->nr_ppas = nr_secs;
 433         rqd->bio = NULL; /* cloned bio if needed */
 434         rqd->private = pblk;
 435         rqd->end_io = pblk_end_io_read;
 436
 437         r_ctx = nvm_rq_to_pdu(rqd);
 438         r_ctx->start_time = jiffies;
 439         r_ctx->lba = blba;
 440         r_ctx->private = bio; /* original bio */
 441
 442         /* Save the index for this bio's start. This is needed in case
 443          * we need to fill a partial read.
 444          */
 445         bio_init_idx = pblk_get_bi_idx(bio);
 446
 447         if (pblk_alloc_rqd_meta(pblk, rqd))
 448                 goto fail_rqd_free;
 449
 450         if (nr_secs > 1)
 451                 pblk_read_ppalist_rq(pblk, rqd, bio, blba, read_bitmap);
 452         else
 453                 pblk_read_rq(pblk, rqd, bio, blba, read_bitmap);
 454
 455         if (bitmap_full(read_bitmap, nr_secs)) {
 456                 atomic_inc(&pblk->inflight_io);
 457                 __pblk_end_io_read(pblk, rqd, false);
 458                 return NVM_IO_DONE;
 459         }
 460
 461         /* All sectors are to be read from the device */
 462         if (bitmap_empty(read_bitmap, rqd->nr_ppas)) {
 463                 struct bio *int_bio = NULL;
 464
 465                 /* Clone read bio to deal with read errors internally */
 466                 int_bio = bio_clone_fast(bio, GFP_KERNEL, &pblk_bio_set);
 467                 if (!int_bio) {
 468                         pblk_err(pblk, "could not clone read bio\n");
 469                         goto fail_end_io;
 470                 }
 471
 472                 rqd->bio = int_bio;
 473
 474                 if (pblk_submit_io(pblk, rqd)) {
 475                         pblk_err(pblk, "read IO submission failed\n");
 476                         ret = NVM_IO_ERR;
 477                         goto fail_end_io;
 478                 }
 479
 480                 return NVM_IO_OK;
 481         }
 482
 483         /* The read bio request could be partially filled by the write buffer,
 484          * but there are some holes that need to be read from the drive.
 485          */
 486         ret = pblk_partial_read_bio(pblk, rqd, bio_init_idx, read_bitmap,
 487                                     nr_secs);
 488         if (ret)
 489                 goto fail_meta_free;
 490
 491         return NVM_IO_OK;
 492
 493 fail_meta_free:
 494         nvm_dev_dma_free(dev->parent, rqd->meta_list, rqd->dma_meta_list);
 495 fail_rqd_free:
 496         pblk_free_rqd(pblk, rqd, PBLK_READ);
 497         return ret;
 498 fail_end_io:
 499         __pblk_end_io_read(pblk, rqd, false);
 500         return ret;
 501 }
 502
 503 static int read_ppalist_rq_gc(struct pblk *pblk, struct nvm_rq *rqd,
 504                               struct pblk_line *line, u64 *lba_list,
 505                               u64 *paddr_list_gc, unsigned int nr_secs)
 506 {
 507         struct ppa_addr ppa_list_l2p[NVM_MAX_VLBA];
 508         struct ppa_addr ppa_gc;
 509         int valid_secs = 0;
 510         int i;
 511
 512         pblk_lookup_l2p_rand(pblk, ppa_list_l2p, lba_list, nr_secs);
 513
 514         for (i = 0; i < nr_secs; i++) {
 515                 if (lba_list[i] == ADDR_EMPTY)
 516                         continue;
 517
 518                 ppa_gc = addr_to_gen_ppa(pblk, paddr_list_gc[i], line->id);
 519                 if (!pblk_ppa_comp(ppa_list_l2p[i], ppa_gc)) {
 520                         paddr_list_gc[i] = lba_list[i] = ADDR_EMPTY;
 521                         continue;
 522                 }
 523
 524                 rqd->ppa_list[valid_secs++] = ppa_list_l2p[i];
 525         }
 526
 527 #ifdef CONFIG_NVM_PBLK_DEBUG
 528         atomic_long_add(valid_secs, &pblk->inflight_reads);
 529 #endif
 530
 531         return valid_secs;
 532 }
 533
 534 static int read_rq_gc(struct pblk *pblk, struct nvm_rq *rqd,
 535                       struct pblk_line *line, sector_t lba,
 536                       u64 paddr_gc)
 537 {
 538         struct ppa_addr ppa_l2p, ppa_gc;
 539         int valid_secs = 0;
 540
 541         if (lba == ADDR_EMPTY)
 542                 goto out;
 543
 544         /* logic error: lba out-of-bounds */
 545         if (lba >= pblk->rl.nr_secs) {
 546                 WARN(1, "pblk: read lba out of bounds\n");
 547                 goto out;
 548         }
 549
 550         spin_lock(&pblk->trans_lock);
 551         ppa_l2p = pblk_trans_map_get(pblk, lba);
 552         spin_unlock(&pblk->trans_lock);
 553
 554         ppa_gc = addr_to_gen_ppa(pblk, paddr_gc, line->id);
 555         if (!pblk_ppa_comp(ppa_l2p, ppa_gc))
 556                 goto out;
 557
 558         rqd->ppa_addr = ppa_l2p;
 559         valid_secs = 1;
 560
 561 #ifdef CONFIG_NVM_PBLK_DEBUG
 562         atomic_long_inc(&pblk->inflight_reads);
 563 #endif
 564
 565 out:
 566         return valid_secs;
 567 }
 568
 569 int pblk_submit_read_gc(struct pblk *pblk, struct pblk_gc_rq *gc_rq)
 570 {
 571         struct nvm_tgt_dev *dev = pblk->dev;
 572         struct nvm_geo *geo = &dev->geo;
 573         struct bio *bio;
 574         struct nvm_rq rqd;
 575         int data_len;
 576         int ret = NVM_IO_OK;
 577
 578         memset(&rqd, 0, sizeof(struct nvm_rq));
 579
 580         ret = pblk_alloc_rqd_meta(pblk, &rqd);
 581         if (ret)
 582                 return ret;
 583
 584         if (gc_rq->nr_secs > 1) {
 585                 gc_rq->secs_to_gc = read_ppalist_rq_gc(pblk, &rqd, gc_rq->line,
 586                                                         gc_rq->lba_list,
 587                                                         gc_rq->paddr_list,
 588                                                         gc_rq->nr_secs);
 589                 if (gc_rq->secs_to_gc == 1)
 590                         rqd.ppa_addr = rqd.ppa_list[0];
 591         } else {
 592                 gc_rq->secs_to_gc = read_rq_gc(pblk, &rqd, gc_rq->line,
 593                                                         gc_rq->lba_list[0],
 594                                                         gc_rq->paddr_list[0]);
 595         }
 596
 597         if (!(gc_rq->secs_to_gc))
 598                 goto out;
 599
 600         data_len = (gc_rq->secs_to_gc) * geo->csecs;
 601         bio = pblk_bio_map_addr(pblk, gc_rq->data, gc_rq->secs_to_gc, data_len,
 602                                                 PBLK_VMALLOC_META, GFP_KERNEL);
 603         if (IS_ERR(bio)) {
 604                 pblk_err(pblk, "could not allocate GC bio (%lu)\n",
 605                                                                 PTR_ERR(bio));
 606                 ret = PTR_ERR(bio);
 607                 goto err_free_dma;
 608         }
 609
 610         bio->bi_iter.bi_sector = 0; /* internal bio */
 611         bio_set_op_attrs(bio, REQ_OP_READ, 0);
 612
 613         rqd.opcode = NVM_OP_PREAD;
 614         rqd.nr_ppas = gc_rq->secs_to_gc;
 615         rqd.bio = bio;
 616
 617         if (pblk_submit_io_sync(pblk, &rqd)) {
 618                 ret = -EIO;
 619                 pblk_err(pblk, "GC read request failed\n");
 620                 goto err_free_bio;
 621         }
 622
 623         pblk_read_check_rand(pblk, &rqd, gc_rq->lba_list, gc_rq->nr_secs);
 624
 625         atomic_dec(&pblk->inflight_io);
 626
 627         if (rqd.error) {
 628                 atomic_long_inc(&pblk->read_failed_gc);
 629 #ifdef CONFIG_NVM_PBLK_DEBUG
 630                 pblk_print_failed_rqd(pblk, &rqd, rqd.error);
 631 #endif
 632         }
 633
 634 #ifdef CONFIG_NVM_PBLK_DEBUG
 635         atomic_long_add(gc_rq->secs_to_gc, &pblk->sync_reads);
 636         atomic_long_add(gc_rq->secs_to_gc, &pblk->recov_gc_reads);
 637         atomic_long_sub(gc_rq->secs_to_gc, &pblk->inflight_reads);
 638 #endif
 639
 640 out:
 641         pblk_free_rqd_meta(pblk, &rqd);
 642         return ret;
 643
 644 err_free_bio:
 645         bio_put(bio);
 646 err_free_dma:
 647         pblk_free_rqd_meta(pblk, &rqd);
 648         return ret;
 649 }