drivers/lightnvm/pblk-write.c

   1 /*
   2  * Copyright (C) 2016 CNEX Labs
   3  * Initial release: Javier Gonzalez <javier@cnexlabs.com>
   4  *                  Matias Bjorling <matias@cnexlabs.com>
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License version
   8  * 2 as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  *
  15  * pblk-write.c - pblk's write path from write buffer to media
  16  */
  17
  18 #include "pblk.h"
  19
  20 static unsigned long pblk_end_w_bio(struct pblk *pblk, struct nvm_rq *rqd,
  21                                     struct pblk_c_ctx *c_ctx)
  22 {
  23         struct nvm_tgt_dev *dev = pblk->dev;
  24         struct bio *original_bio;
  25         unsigned long ret;
  26         int i;
  27
  28         for (i = 0; i < c_ctx->nr_valid; i++) {
  29                 struct pblk_w_ctx *w_ctx;
  30
  31                 w_ctx = pblk_rb_w_ctx(&pblk->rwb, c_ctx->sentry + i);
  32                 while ((original_bio = bio_list_pop(&w_ctx->bios)))
  33                         bio_endio(original_bio);
  34         }
  35
  36 #ifdef CONFIG_NVM_DEBUG
  37         atomic_long_add(c_ctx->nr_valid, &pblk->sync_writes);
  38 #endif
  39
  40         ret = pblk_rb_sync_advance(&pblk->rwb, c_ctx->nr_valid);
  41
  42         nvm_dev_dma_free(dev->parent, rqd->meta_list, rqd->dma_meta_list);
  43
  44         bio_put(rqd->bio);
  45         pblk_free_rqd(pblk, rqd, WRITE);
  46
  47         return ret;
  48 }
  49
  50 static unsigned long pblk_end_queued_w_bio(struct pblk *pblk,
  51                                            struct nvm_rq *rqd,
  52                                            struct pblk_c_ctx *c_ctx)
  53 {
  54         list_del(&c_ctx->list);
  55         return pblk_end_w_bio(pblk, rqd, c_ctx);
  56 }
  57
  58 static void pblk_complete_write(struct pblk *pblk, struct nvm_rq *rqd,
  59                                 struct pblk_c_ctx *c_ctx)
  60 {
  61         struct pblk_c_ctx *c, *r;
  62         unsigned long flags;
  63         unsigned long pos;
  64
  65 #ifdef CONFIG_NVM_DEBUG
  66         atomic_long_sub(c_ctx->nr_valid, &pblk->inflight_writes);
  67 #endif
  68
  69         pblk_up_rq(pblk, rqd->ppa_list, rqd->nr_ppas, c_ctx->lun_bitmap);
  70
  71         pos = pblk_rb_sync_init(&pblk->rwb, &flags);
  72         if (pos == c_ctx->sentry) {
  73                 pos = pblk_end_w_bio(pblk, rqd, c_ctx);
  74
  75 retry:
  76                 list_for_each_entry_safe(c, r, &pblk->compl_list, list) {
  77                         rqd = nvm_rq_from_c_ctx(c);
  78                         if (c->sentry == pos) {
  79                                 pos = pblk_end_queued_w_bio(pblk, rqd, c);
  80                                 goto retry;
  81                         }
  82                 }
  83         } else {
  84                 WARN_ON(nvm_rq_from_c_ctx(c_ctx) != rqd);
  85                 list_add_tail(&c_ctx->list, &pblk->compl_list);
  86         }
  87         pblk_rb_sync_end(&pblk->rwb, &flags);
  88 }
  89
  90 /* When a write fails, we are not sure whether the block has grown bad or a page
  91  * range is more susceptible to write errors. If a high number of pages fail, we
  92  * assume that the block is bad and we mark it accordingly. In all cases, we
  93  * remap and resubmit the failed entries as fast as possible; if a flush is
  94  * waiting on a completion, the whole stack would stall otherwise.
  95  */
  96 static void pblk_end_w_fail(struct pblk *pblk, struct nvm_rq *rqd)
  97 {
  98         void *comp_bits = &rqd->ppa_status;
  99         struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
 100         struct pblk_rec_ctx *recovery;
 101         struct ppa_addr *ppa_list = rqd->ppa_list;
 102         int nr_ppas = rqd->nr_ppas;
 103         unsigned int c_entries;
 104         int bit, ret;
 105
 106         if (unlikely(nr_ppas == 1))
 107                 ppa_list = &rqd->ppa_addr;
 108
 109         recovery = mempool_alloc(pblk->rec_pool, GFP_ATOMIC);
 110         if (!recovery) {
 111                 pr_err("pblk: could not allocate recovery context\n");
 112                 return;
 113         }
 114         INIT_LIST_HEAD(&recovery->failed);
 115
 116         bit = -1;
 117         while ((bit = find_next_bit(comp_bits, nr_ppas, bit + 1)) < nr_ppas) {
 118                 struct pblk_rb_entry *entry;
 119                 struct ppa_addr ppa;
 120
 121                 /* Logic error */
 122                 if (bit > c_ctx->nr_valid) {
 123                         WARN_ONCE(1, "pblk: corrupted write request\n");
 124                         mempool_free(recovery, pblk->rec_pool);
 125                         goto out;
 126                 }
 127
 128                 ppa = ppa_list[bit];
 129                 entry = pblk_rb_sync_scan_entry(&pblk->rwb, &ppa);
 130                 if (!entry) {
 131                         pr_err("pblk: could not scan entry on write failure\n");
 132                         mempool_free(recovery, pblk->rec_pool);
 133                         goto out;
 134                 }
 135
 136                 /* The list is filled first and emptied afterwards. No need for
 137                  * protecting it with a lock
 138                  */
 139                 list_add_tail(&entry->index, &recovery->failed);
 140         }
 141
 142         c_entries = find_first_bit(comp_bits, nr_ppas);
 143         ret = pblk_recov_setup_rq(pblk, c_ctx, recovery, comp_bits, c_entries);
 144         if (ret) {
 145                 pr_err("pblk: could not recover from write failure\n");
 146                 mempool_free(recovery, pblk->rec_pool);
 147                 goto out;
 148         }
 149
 150         INIT_WORK(&recovery->ws_rec, pblk_submit_rec);
 151         queue_work(pblk->close_wq, &recovery->ws_rec);
 152
 153 out:
 154         pblk_complete_write(pblk, rqd, c_ctx);
 155 }
 156
 157 static void pblk_end_io_write(struct nvm_rq *rqd)
 158 {
 159         struct pblk *pblk = rqd->private;
 160         struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
 161
 162         if (rqd->error) {
 163                 pblk_log_write_err(pblk, rqd);
 164                 return pblk_end_w_fail(pblk, rqd);
 165         }
 166 #ifdef CONFIG_NVM_DEBUG
 167         else
 168                 WARN_ONCE(rqd->bio->bi_status, "pblk: corrupted write error\n");
 169 #endif
 170
 171         pblk_complete_write(pblk, rqd, c_ctx);
 172         atomic_dec(&pblk->inflight_io);
 173 }
 174
 175 static void pblk_end_io_write_meta(struct nvm_rq *rqd)
 176 {
 177         struct pblk *pblk = rqd->private;
 178         struct nvm_tgt_dev *dev = pblk->dev;
 179         struct pblk_g_ctx *m_ctx = nvm_rq_to_pdu(rqd);
 180         struct pblk_line *line = m_ctx->private;
 181         struct pblk_emeta *emeta = line->emeta;
 182         int sync;
 183
 184         pblk_up_page(pblk, rqd->ppa_list, rqd->nr_ppas);
 185
 186         if (rqd->error) {
 187                 pblk_log_write_err(pblk, rqd);
 188                 pr_err("pblk: metadata I/O failed. Line %d\n", line->id);
 189         }
 190 #ifdef CONFIG_NVM_DEBUG
 191         else
 192                 WARN_ONCE(rqd->bio->bi_status, "pblk: corrupted write error\n");
 193 #endif
 194
 195         sync = atomic_add_return(rqd->nr_ppas, &emeta->sync);
 196         if (sync == emeta->nr_entries)
 197                 pblk_line_run_ws(pblk, line, NULL, pblk_line_close_ws,
 198                                                                 pblk->close_wq);
 199
 200         bio_put(rqd->bio);
 201         nvm_dev_dma_free(dev->parent, rqd->meta_list, rqd->dma_meta_list);
 202         pblk_free_rqd(pblk, rqd, READ);
 203
 204         atomic_dec(&pblk->inflight_io);
 205 }
 206
 207 static int pblk_alloc_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
 208                            unsigned int nr_secs,
 209                            nvm_end_io_fn(*end_io))
 210 {
 211         struct nvm_tgt_dev *dev = pblk->dev;
 212
 213         /* Setup write request */
 214         rqd->opcode = NVM_OP_PWRITE;
 215         rqd->nr_ppas = nr_secs;
 216         rqd->flags = pblk_set_progr_mode(pblk, WRITE);
 217         rqd->private = pblk;
 218         rqd->end_io = end_io;
 219
 220         rqd->meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
 221                                                         &rqd->dma_meta_list);
 222         if (!rqd->meta_list)
 223                 return -ENOMEM;
 224
 225         rqd->ppa_list = rqd->meta_list + pblk_dma_meta_size;
 226         rqd->dma_ppa_list = rqd->dma_meta_list + pblk_dma_meta_size;
 227
 228         return 0;
 229 }
 230
 231 static int pblk_setup_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
 232                            struct pblk_c_ctx *c_ctx, struct ppa_addr *erase_ppa)
 233 {
 234         struct pblk_line_meta *lm = &pblk->lm;
 235         struct pblk_line *e_line = pblk_line_get_erase(pblk);
 236         unsigned int valid = c_ctx->nr_valid;
 237         unsigned int padded = c_ctx->nr_padded;
 238         unsigned int nr_secs = valid + padded;
 239         unsigned long *lun_bitmap;
 240         int ret = 0;
 241
 242         lun_bitmap = kzalloc(lm->lun_bitmap_len, GFP_KERNEL);
 243         if (!lun_bitmap)
 244                 return -ENOMEM;
 245         c_ctx->lun_bitmap = lun_bitmap;
 246
 247         ret = pblk_alloc_w_rq(pblk, rqd, nr_secs, pblk_end_io_write);
 248         if (ret) {
 249                 kfree(lun_bitmap);
 250                 return ret;
 251         }
 252
 253         if (likely(!e_line || !atomic_read(&e_line->left_eblks)))
 254                 pblk_map_rq(pblk, rqd, c_ctx->sentry, lun_bitmap, valid, 0);
 255         else
 256                 pblk_map_erase_rq(pblk, rqd, c_ctx->sentry, lun_bitmap,
 257                                                         valid, erase_ppa);
 258
 259         return 0;
 260 }
 261
 262 int pblk_setup_w_rec_rq(struct pblk *pblk, struct nvm_rq *rqd,
 263                         struct pblk_c_ctx *c_ctx)
 264 {
 265         struct pblk_line_meta *lm = &pblk->lm;
 266         unsigned long *lun_bitmap;
 267         int ret;
 268
 269         lun_bitmap = kzalloc(lm->lun_bitmap_len, GFP_KERNEL);
 270         if (!lun_bitmap)
 271                 return -ENOMEM;
 272
 273         c_ctx->lun_bitmap = lun_bitmap;
 274
 275         ret = pblk_alloc_w_rq(pblk, rqd, rqd->nr_ppas, pblk_end_io_write);
 276         if (ret)
 277                 return ret;
 278
 279         pblk_map_rq(pblk, rqd, c_ctx->sentry, lun_bitmap, c_ctx->nr_valid, 0);
 280
 281         rqd->ppa_status = (u64)0;
 282         rqd->flags = pblk_set_progr_mode(pblk, WRITE);
 283
 284         return ret;
 285 }
 286
 287 static int pblk_calc_secs_to_sync(struct pblk *pblk, unsigned int secs_avail,
 288                                   unsigned int secs_to_flush)
 289 {
 290         int secs_to_sync;
 291
 292         secs_to_sync = pblk_calc_secs(pblk, secs_avail, secs_to_flush);
 293
 294 #ifdef CONFIG_NVM_DEBUG
 295         if ((!secs_to_sync && secs_to_flush)
 296                         || (secs_to_sync < 0)
 297                         || (secs_to_sync > secs_avail && !secs_to_flush)) {
 298                 pr_err("pblk: bad sector calculation (a:%d,s:%d,f:%d)\n",
 299                                 secs_avail, secs_to_sync, secs_to_flush);
 300         }
 301 #endif
 302
 303         return secs_to_sync;
 304 }
 305
 306 static inline int pblk_valid_meta_ppa(struct pblk *pblk,
 307                                       struct pblk_line *meta_line,
 308                                       struct ppa_addr *ppa_list, int nr_ppas)
 309 {
 310         struct nvm_tgt_dev *dev = pblk->dev;
 311         struct nvm_geo *geo = &dev->geo;
 312         struct pblk_line *data_line;
 313         struct ppa_addr ppa, ppa_opt;
 314         u64 paddr;
 315         int i;
 316
 317         data_line = &pblk->lines[pblk_dev_ppa_to_line(ppa_list[0])];
 318         paddr = pblk_lookup_page(pblk, meta_line);
 319         ppa = addr_to_gen_ppa(pblk, paddr, 0);
 320
 321         if (test_bit(pblk_ppa_to_pos(geo, ppa), data_line->blk_bitmap))
 322                 return 1;
 323
 324         /* Schedule a metadata I/O that is half the distance from the data I/O
 325          * with regards to the number of LUNs forming the pblk instance. This
 326          * balances LUN conflicts across every I/O.
 327          *
 328          * When the LUN configuration changes (e.g., due to GC), this distance
 329          * can align, which would result on a LUN deadlock. In this case, modify
 330          * the distance to not be optimal, but allow metadata I/Os to succeed.
 331          */
 332         ppa_opt = addr_to_gen_ppa(pblk, paddr + data_line->meta_distance, 0);
 333         if (unlikely(ppa_opt.ppa == ppa.ppa)) {
 334                 data_line->meta_distance--;
 335                 return 0;
 336         }
 337
 338         for (i = 0; i < nr_ppas; i += pblk->min_write_pgs)
 339                 if (ppa_list[i].g.ch == ppa_opt.g.ch &&
 340                                         ppa_list[i].g.lun == ppa_opt.g.lun)
 341                         return 1;
 342
 343         if (test_bit(pblk_ppa_to_pos(geo, ppa_opt), data_line->blk_bitmap)) {
 344                 for (i = 0; i < nr_ppas; i += pblk->min_write_pgs)
 345                         if (ppa_list[i].g.ch == ppa.g.ch &&
 346                                                 ppa_list[i].g.lun == ppa.g.lun)
 347                                 return 0;
 348
 349                 return 1;
 350         }
 351
 352         return 0;
 353 }
 354
 355 int pblk_submit_meta_io(struct pblk *pblk, struct pblk_line *meta_line)
 356 {
 357         struct nvm_tgt_dev *dev = pblk->dev;
 358         struct nvm_geo *geo = &dev->geo;
 359         struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 360         struct pblk_line_meta *lm = &pblk->lm;
 361         struct pblk_emeta *emeta = meta_line->emeta;
 362         struct pblk_g_ctx *m_ctx;
 363         struct bio *bio;
 364         struct nvm_rq *rqd;
 365         void *data;
 366         u64 paddr;
 367         int rq_ppas = pblk->min_write_pgs;
 368         int id = meta_line->id;
 369         int rq_len;
 370         int i, j;
 371         int ret;
 372
 373         rqd = pblk_alloc_rqd(pblk, READ);
 374         if (IS_ERR(rqd)) {
 375                 pr_err("pblk: cannot allocate write req.\n");
 376                 return PTR_ERR(rqd);
 377         }
 378         m_ctx = nvm_rq_to_pdu(rqd);
 379         m_ctx->private = meta_line;
 380
 381         rq_len = rq_ppas * geo->sec_size;
 382         data = ((void *)emeta->buf) + emeta->mem;
 383
 384         bio = pblk_bio_map_addr(pblk, data, rq_ppas, rq_len,
 385                                         l_mg->emeta_alloc_type, GFP_KERNEL);
 386         if (IS_ERR(bio)) {
 387                 ret = PTR_ERR(bio);
 388                 goto fail_free_rqd;
 389         }
 390         bio->bi_iter.bi_sector = 0; /* internal bio */
 391         bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
 392         rqd->bio = bio;
 393
 394         ret = pblk_alloc_w_rq(pblk, rqd, rq_ppas, pblk_end_io_write_meta);
 395         if (ret)
 396                 goto fail_free_bio;
 397
 398         for (i = 0; i < rqd->nr_ppas; ) {
 399                 spin_lock(&meta_line->lock);
 400                 paddr = __pblk_alloc_page(pblk, meta_line, rq_ppas);
 401                 spin_unlock(&meta_line->lock);
 402                 for (j = 0; j < rq_ppas; j++, i++, paddr++)
 403                         rqd->ppa_list[i] = addr_to_gen_ppa(pblk, paddr, id);
 404         }
 405
 406         emeta->mem += rq_len;
 407         if (emeta->mem >= lm->emeta_len[0]) {
 408                 spin_lock(&l_mg->close_lock);
 409                 list_del(&meta_line->list);
 410                 WARN(!bitmap_full(meta_line->map_bitmap, lm->sec_per_line),
 411                                 "pblk: corrupt meta line %d\n", meta_line->id);
 412                 spin_unlock(&l_mg->close_lock);
 413         }
 414
 415         pblk_down_page(pblk, rqd->ppa_list, rqd->nr_ppas);
 416
 417         ret = pblk_submit_io(pblk, rqd);
 418         if (ret) {
 419                 pr_err("pblk: emeta I/O submission failed: %d\n", ret);
 420                 goto fail_rollback;
 421         }
 422
 423         return NVM_IO_OK;
 424
 425 fail_rollback:
 426         pblk_up_page(pblk, rqd->ppa_list, rqd->nr_ppas);
 427         spin_lock(&l_mg->close_lock);
 428         pblk_dealloc_page(pblk, meta_line, rq_ppas);
 429         list_add(&meta_line->list, &meta_line->list);
 430         spin_unlock(&l_mg->close_lock);
 431
 432         nvm_dev_dma_free(dev->parent, rqd->meta_list, rqd->dma_meta_list);
 433 fail_free_bio:
 434         if (likely(l_mg->emeta_alloc_type == PBLK_VMALLOC_META))
 435                 bio_put(bio);
 436 fail_free_rqd:
 437         pblk_free_rqd(pblk, rqd, READ);
 438         return ret;
 439 }
 440
 441 static int pblk_sched_meta_io(struct pblk *pblk, struct ppa_addr *prev_list,
 442                                int prev_n)
 443 {
 444         struct pblk_line_meta *lm = &pblk->lm;
 445         struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 446         struct pblk_line *meta_line;
 447
 448         spin_lock(&l_mg->close_lock);
 449 retry:
 450         if (list_empty(&l_mg->emeta_list)) {
 451                 spin_unlock(&l_mg->close_lock);
 452                 return 0;
 453         }
 454         meta_line = list_first_entry(&l_mg->emeta_list, struct pblk_line, list);
 455         if (bitmap_full(meta_line->map_bitmap, lm->sec_per_line))
 456                 goto retry;
 457         spin_unlock(&l_mg->close_lock);
 458
 459         if (!pblk_valid_meta_ppa(pblk, meta_line, prev_list, prev_n))
 460                 return 0;
 461
 462         return pblk_submit_meta_io(pblk, meta_line);
 463 }
 464
 465 static int pblk_submit_io_set(struct pblk *pblk, struct nvm_rq *rqd)
 466 {
 467         struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
 468         struct ppa_addr erase_ppa;
 469         int err;
 470
 471         ppa_set_empty(&erase_ppa);
 472
 473         /* Assign lbas to ppas and populate request structure */
 474         err = pblk_setup_w_rq(pblk, rqd, c_ctx, &erase_ppa);
 475         if (err) {
 476                 pr_err("pblk: could not setup write request: %d\n", err);
 477                 return NVM_IO_ERR;
 478         }
 479
 480         if (likely(ppa_empty(erase_ppa))) {
 481                 /* Submit metadata write for previous data line */
 482                 err = pblk_sched_meta_io(pblk, rqd->ppa_list, rqd->nr_ppas);
 483                 if (err) {
 484                         pr_err("pblk: metadata I/O submission failed: %d", err);
 485                         return NVM_IO_ERR;
 486                 }
 487
 488                 /* Submit data write for current data line */
 489                 err = pblk_submit_io(pblk, rqd);
 490                 if (err) {
 491                         pr_err("pblk: data I/O submission failed: %d\n", err);
 492                         return NVM_IO_ERR;
 493                 }
 494         } else {
 495                 /* Submit data write for current data line */
 496                 err = pblk_submit_io(pblk, rqd);
 497                 if (err) {
 498                         pr_err("pblk: data I/O submission failed: %d\n", err);
 499                         return NVM_IO_ERR;
 500                 }
 501
 502                 /* Submit available erase for next data line */
 503                 if (pblk_blk_erase_async(pblk, erase_ppa)) {
 504                         struct pblk_line *e_line = pblk_line_get_erase(pblk);
 505                         struct nvm_tgt_dev *dev = pblk->dev;
 506                         struct nvm_geo *geo = &dev->geo;
 507                         int bit;
 508
 509                         atomic_inc(&e_line->left_eblks);
 510                         bit = pblk_ppa_to_pos(geo, erase_ppa);
 511                         WARN_ON(!test_and_clear_bit(bit, e_line->erase_bitmap));
 512                 }
 513         }
 514
 515         return NVM_IO_OK;
 516 }
 517
 518 static void pblk_free_write_rqd(struct pblk *pblk, struct nvm_rq *rqd)
 519 {
 520         struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
 521         struct bio *bio = rqd->bio;
 522
 523         if (c_ctx->nr_padded)
 524                 pblk_bio_free_pages(pblk, bio, rqd->nr_ppas, c_ctx->nr_padded);
 525 }
 526
 527 static int pblk_submit_write(struct pblk *pblk)
 528 {
 529         struct bio *bio;
 530         struct nvm_rq *rqd;
 531         unsigned int secs_avail, secs_to_sync, secs_to_com;
 532         unsigned int secs_to_flush;
 533         unsigned long pos;
 534
 535         /* If there are no sectors in the cache, flushes (bios without data)
 536          * will be cleared on the cache threads
 537          */
 538         secs_avail = pblk_rb_read_count(&pblk->rwb);
 539         if (!secs_avail)
 540                 return 1;
 541
 542         secs_to_flush = pblk_rb_sync_point_count(&pblk->rwb);
 543         if (!secs_to_flush && secs_avail < pblk->min_write_pgs)
 544                 return 1;
 545
 546         rqd = pblk_alloc_rqd(pblk, WRITE);
 547         if (IS_ERR(rqd)) {
 548                 pr_err("pblk: cannot allocate write req.\n");
 549                 return 1;
 550         }
 551
 552         bio = bio_alloc(GFP_KERNEL, pblk->max_write_pgs);
 553         if (!bio) {
 554                 pr_err("pblk: cannot allocate write bio\n");
 555                 goto fail_free_rqd;
 556         }
 557         bio->bi_iter.bi_sector = 0; /* internal bio */
 558         bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
 559         rqd->bio = bio;
 560
 561         secs_to_sync = pblk_calc_secs_to_sync(pblk, secs_avail, secs_to_flush);
 562         if (secs_to_sync > pblk->max_write_pgs) {
 563                 pr_err("pblk: bad buffer sync calculation\n");
 564                 goto fail_put_bio;
 565         }
 566
 567         secs_to_com = (secs_to_sync > secs_avail) ? secs_avail : secs_to_sync;
 568         pos = pblk_rb_read_commit(&pblk->rwb, secs_to_com);
 569
 570         if (pblk_rb_read_to_bio(&pblk->rwb, rqd, bio, pos, secs_to_sync,
 571                                                                 secs_avail)) {
 572                 pr_err("pblk: corrupted write bio\n");
 573                 goto fail_put_bio;
 574         }
 575
 576         if (pblk_submit_io_set(pblk, rqd))
 577                 goto fail_free_bio;
 578
 579 #ifdef CONFIG_NVM_DEBUG
 580         atomic_long_add(secs_to_sync, &pblk->sub_writes);
 581 #endif
 582
 583         return 0;
 584
 585 fail_free_bio:
 586         pblk_free_write_rqd(pblk, rqd);
 587 fail_put_bio:
 588         bio_put(bio);
 589 fail_free_rqd:
 590         pblk_free_rqd(pblk, rqd, WRITE);
 591
 592         return 1;
 593 }
 594
 595 int pblk_write_ts(void *data)
 596 {
 597         struct pblk *pblk = data;
 598
 599         while (!kthread_should_stop()) {
 600                 if (!pblk_submit_write(pblk))
 601                         continue;
 602                 set_current_state(TASK_INTERRUPTIBLE);
 603                 io_schedule();
 604         }
 605
 606         return 0;
 607 }