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         if (rqd->meta_list)
  43                 nvm_dev_dma_free(dev->parent, rqd->meta_list,
  44                                                         rqd->dma_meta_list);
  45
  46         bio_put(rqd->bio);
  47         pblk_free_rqd(pblk, rqd, WRITE);
  48
  49         return ret;
  50 }
  51
  52 static unsigned long pblk_end_queued_w_bio(struct pblk *pblk,
  53                                            struct nvm_rq *rqd,
  54                                            struct pblk_c_ctx *c_ctx)
  55 {
  56         list_del(&c_ctx->list);
  57         return pblk_end_w_bio(pblk, rqd, c_ctx);
  58 }
  59
  60 static void pblk_complete_write(struct pblk *pblk, struct nvm_rq *rqd,
  61                                 struct pblk_c_ctx *c_ctx)
  62 {
  63         struct pblk_c_ctx *c, *r;
  64         unsigned long flags;
  65         unsigned long pos;
  66
  67 #ifdef CONFIG_NVM_DEBUG
  68         atomic_long_sub(c_ctx->nr_valid, &pblk->inflight_writes);
  69 #endif
  70
  71         pblk_up_rq(pblk, rqd->ppa_list, rqd->nr_ppas, c_ctx->lun_bitmap);
  72
  73         pos = pblk_rb_sync_init(&pblk->rwb, &flags);
  74         if (pos == c_ctx->sentry) {
  75                 pos = pblk_end_w_bio(pblk, rqd, c_ctx);
  76
  77 retry:
  78                 list_for_each_entry_safe(c, r, &pblk->compl_list, list) {
  79                         rqd = nvm_rq_from_c_ctx(c);
  80                         if (c->sentry == pos) {
  81                                 pos = pblk_end_queued_w_bio(pblk, rqd, c);
  82                                 goto retry;
  83                         }
  84                 }
  85         } else {
  86                 WARN_ON(nvm_rq_from_c_ctx(c_ctx) != rqd);
  87                 list_add_tail(&c_ctx->list, &pblk->compl_list);
  88         }
  89         pblk_rb_sync_end(&pblk->rwb, &flags);
  90 }
  91
  92 /* When a write fails, we are not sure whether the block has grown bad or a page
  93  * range is more susceptible to write errors. If a high number of pages fail, we
  94  * assume that the block is bad and we mark it accordingly. In all cases, we
  95  * remap and resubmit the failed entries as fast as possible; if a flush is
  96  * waiting on a completion, the whole stack would stall otherwise.
  97  */
  98 static void pblk_end_w_fail(struct pblk *pblk, struct nvm_rq *rqd)
  99 {
 100         void *comp_bits = &rqd->ppa_status;
 101         struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
 102         struct pblk_rec_ctx *recovery;
 103         struct ppa_addr *ppa_list = rqd->ppa_list;
 104         int nr_ppas = rqd->nr_ppas;
 105         unsigned int c_entries;
 106         int bit, ret;
 107
 108         if (unlikely(nr_ppas == 1))
 109                 ppa_list = &rqd->ppa_addr;
 110
 111         recovery = mempool_alloc(pblk->rec_pool, GFP_ATOMIC);
 112         if (!recovery) {
 113                 pr_err("pblk: could not allocate recovery context\n");
 114                 return;
 115         }
 116         INIT_LIST_HEAD(&recovery->failed);
 117
 118         bit = -1;
 119         while ((bit = find_next_bit(comp_bits, nr_ppas, bit + 1)) < nr_ppas) {
 120                 struct pblk_rb_entry *entry;
 121                 struct ppa_addr ppa;
 122
 123                 /* Logic error */
 124                 if (bit > c_ctx->nr_valid) {
 125                         WARN_ONCE(1, "pblk: corrupted write request\n");
 126                         mempool_free(recovery, pblk->rec_pool);
 127                         goto out;
 128                 }
 129
 130                 ppa = ppa_list[bit];
 131                 entry = pblk_rb_sync_scan_entry(&pblk->rwb, &ppa);
 132                 if (!entry) {
 133                         pr_err("pblk: could not scan entry on write failure\n");
 134                         mempool_free(recovery, pblk->rec_pool);
 135                         goto out;
 136                 }
 137
 138                 /* The list is filled first and emptied afterwards. No need for
 139                  * protecting it with a lock
 140                  */
 141                 list_add_tail(&entry->index, &recovery->failed);
 142         }
 143
 144         c_entries = find_first_bit(comp_bits, nr_ppas);
 145         ret = pblk_recov_setup_rq(pblk, c_ctx, recovery, comp_bits, c_entries);
 146         if (ret) {
 147                 pr_err("pblk: could not recover from write failure\n");
 148                 mempool_free(recovery, pblk->rec_pool);
 149                 goto out;
 150         }
 151
 152         INIT_WORK(&recovery->ws_rec, pblk_submit_rec);
 153         queue_work(pblk->kw_wq, &recovery->ws_rec);
 154
 155 out:
 156         pblk_complete_write(pblk, rqd, c_ctx);
 157 }
 158
 159 static void pblk_end_io_write(struct nvm_rq *rqd)
 160 {
 161         struct pblk *pblk = rqd->private;
 162         struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
 163
 164         if (rqd->error) {
 165                 pblk_log_write_err(pblk, rqd);
 166                 return pblk_end_w_fail(pblk, rqd);
 167         }
 168 #ifdef CONFIG_NVM_DEBUG
 169         else
 170                 WARN_ONCE(rqd->bio->bi_status, "pblk: corrupted write error\n");
 171 #endif
 172
 173         pblk_complete_write(pblk, rqd, c_ctx);
 174 }
 175
 176 static void pblk_end_io_write_meta(struct nvm_rq *rqd)
 177 {
 178         struct pblk *pblk = rqd->private;
 179         struct nvm_tgt_dev *dev = pblk->dev;
 180         struct nvm_geo *geo = &dev->geo;
 181         struct pblk_g_ctx *m_ctx = nvm_rq_to_pdu(rqd);
 182         struct pblk_line *line = m_ctx->private;
 183         struct pblk_emeta *emeta = line->emeta;
 184         int pos = pblk_ppa_to_pos(geo, rqd->ppa_list[0]);
 185         struct pblk_lun *rlun = &pblk->luns[pos];
 186         int sync;
 187
 188         up(&rlun->wr_sem);
 189
 190         if (rqd->error) {
 191                 pblk_log_write_err(pblk, rqd);
 192                 pr_err("pblk: metadata I/O failed\n");
 193         }
 194 #ifdef CONFIG_NVM_DEBUG
 195         else
 196                 WARN_ONCE(rqd->bio->bi_status, "pblk: corrupted write error\n");
 197 #endif
 198
 199         sync = atomic_add_return(rqd->nr_ppas, &emeta->sync);
 200         if (sync == emeta->nr_entries)
 201                 pblk_line_run_ws(pblk, line, NULL, pblk_line_close_ws);
 202
 203         bio_put(rqd->bio);
 204         pblk_free_rqd(pblk, rqd, READ);
 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         if (unlikely(nr_secs == 1))
 226                 return 0;
 227
 228         rqd->ppa_list = rqd->meta_list + pblk_dma_meta_size;
 229         rqd->dma_ppa_list = rqd->dma_meta_list + pblk_dma_meta_size;
 230
 231         return 0;
 232 }
 233
 234 static int pblk_setup_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
 235                            struct pblk_c_ctx *c_ctx, struct ppa_addr *erase_ppa)
 236 {
 237         struct pblk_line_meta *lm = &pblk->lm;
 238         struct pblk_line *e_line = pblk_line_get_erase(pblk);
 239         unsigned int valid = c_ctx->nr_valid;
 240         unsigned int padded = c_ctx->nr_padded;
 241         unsigned int nr_secs = valid + padded;
 242         unsigned long *lun_bitmap;
 243         int ret = 0;
 244
 245         lun_bitmap = kzalloc(lm->lun_bitmap_len, GFP_KERNEL);
 246         if (!lun_bitmap)
 247                 return -ENOMEM;
 248         c_ctx->lun_bitmap = lun_bitmap;
 249
 250         ret = pblk_alloc_w_rq(pblk, rqd, nr_secs, pblk_end_io_write);
 251         if (ret) {
 252                 kfree(lun_bitmap);
 253                 return ret;
 254         }
 255
 256         if (likely(!atomic_read(&e_line->left_eblks) || !e_line))
 257                 pblk_map_rq(pblk, rqd, c_ctx->sentry, lun_bitmap, valid, 0);
 258         else
 259                 pblk_map_erase_rq(pblk, rqd, c_ctx->sentry, lun_bitmap,
 260                                                         valid, erase_ppa);
 261
 262         return 0;
 263 }
 264
 265 int pblk_setup_w_rec_rq(struct pblk *pblk, struct nvm_rq *rqd,
 266                         struct pblk_c_ctx *c_ctx)
 267 {
 268         struct pblk_line_meta *lm = &pblk->lm;
 269         unsigned long *lun_bitmap;
 270         int ret;
 271
 272         lun_bitmap = kzalloc(lm->lun_bitmap_len, GFP_KERNEL);
 273         if (!lun_bitmap)
 274                 return -ENOMEM;
 275
 276         c_ctx->lun_bitmap = lun_bitmap;
 277
 278         ret = pblk_alloc_w_rq(pblk, rqd, rqd->nr_ppas, pblk_end_io_write);
 279         if (ret)
 280                 return ret;
 281
 282         pblk_map_rq(pblk, rqd, c_ctx->sentry, lun_bitmap, c_ctx->nr_valid, 0);
 283
 284         rqd->ppa_status = (u64)0;
 285         rqd->flags = pblk_set_progr_mode(pblk, WRITE);
 286
 287         return ret;
 288 }
 289
 290 static int pblk_calc_secs_to_sync(struct pblk *pblk, unsigned int secs_avail,
 291                                   unsigned int secs_to_flush)
 292 {
 293         int secs_to_sync;
 294
 295         secs_to_sync = pblk_calc_secs(pblk, secs_avail, secs_to_flush);
 296
 297 #ifdef CONFIG_NVM_DEBUG
 298         if ((!secs_to_sync && secs_to_flush)
 299                         || (secs_to_sync < 0)
 300                         || (secs_to_sync > secs_avail && !secs_to_flush)) {
 301                 pr_err("pblk: bad sector calculation (a:%d,s:%d,f:%d)\n",
 302                                 secs_avail, secs_to_sync, secs_to_flush);
 303         }
 304 #endif
 305
 306         return secs_to_sync;
 307 }
 308
 309 static inline int pblk_valid_meta_ppa(struct pblk *pblk,
 310                                       struct pblk_line *meta_line,
 311                                       struct ppa_addr *ppa_list, int nr_ppas)
 312 {
 313         struct nvm_tgt_dev *dev = pblk->dev;
 314         struct nvm_geo *geo = &dev->geo;
 315         struct pblk_line *data_line;
 316         struct ppa_addr ppa, ppa_opt;
 317         u64 paddr;
 318         int i;
 319
 320         data_line = &pblk->lines[pblk_dev_ppa_to_line(ppa_list[0])];
 321         paddr = pblk_lookup_page(pblk, meta_line);
 322         ppa = addr_to_gen_ppa(pblk, paddr, 0);
 323
 324         if (test_bit(pblk_ppa_to_pos(geo, ppa), data_line->blk_bitmap))
 325                 return 1;
 326
 327         /* Schedule a metadata I/O that is half the distance from the data I/O
 328          * with regards to the number of LUNs forming the pblk instance. This
 329          * balances LUN conflicts across every I/O.
 330          *
 331          * When the LUN configuration changes (e.g., due to GC), this distance
 332          * can align, which would result on a LUN deadlock. In this case, modify
 333          * the distance to not be optimal, but allow metadata I/Os to succeed.
 334          */
 335         ppa_opt = addr_to_gen_ppa(pblk, paddr + data_line->meta_distance, 0);
 336         if (unlikely(ppa_opt.ppa == ppa.ppa)) {
 337                 data_line->meta_distance--;
 338                 return 0;
 339         }
 340
 341         for (i = 0; i < nr_ppas; i += pblk->min_write_pgs)
 342                 if (ppa_list[i].g.ch == ppa_opt.g.ch &&
 343                                         ppa_list[i].g.lun == ppa_opt.g.lun)
 344                         return 1;
 345
 346         if (test_bit(pblk_ppa_to_pos(geo, ppa_opt), data_line->blk_bitmap)) {
 347                 for (i = 0; i < nr_ppas; i += pblk->min_write_pgs)
 348                         if (ppa_list[i].g.ch == ppa.g.ch &&
 349                                                 ppa_list[i].g.lun == ppa.g.lun)
 350                                 return 0;
 351
 352                 return 1;
 353         }
 354
 355         return 0;
 356 }
 357
 358 int pblk_submit_meta_io(struct pblk *pblk, struct pblk_line *meta_line)
 359 {
 360         struct nvm_tgt_dev *dev = pblk->dev;
 361         struct nvm_geo *geo = &dev->geo;
 362         struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 363         struct pblk_line_meta *lm = &pblk->lm;
 364         struct pblk_emeta *emeta = meta_line->emeta;
 365         struct pblk_g_ctx *m_ctx;
 366         struct pblk_lun *rlun;
 367         struct bio *bio;
 368         struct nvm_rq *rqd;
 369         void *data;
 370         u64 paddr;
 371         int rq_ppas = pblk->min_write_pgs;
 372         int id = meta_line->id;
 373         int rq_len;
 374         int i, j;
 375         int ret;
 376
 377         rqd = pblk_alloc_rqd(pblk, READ);
 378         if (IS_ERR(rqd)) {
 379                 pr_err("pblk: cannot allocate write req.\n");
 380                 return PTR_ERR(rqd);
 381         }
 382         m_ctx = nvm_rq_to_pdu(rqd);
 383         m_ctx->private = meta_line;
 384
 385         rq_len = rq_ppas * geo->sec_size;
 386         data = ((void *)emeta->buf) + emeta->mem;
 387
 388         bio = pblk_bio_map_addr(pblk, data, rq_ppas, rq_len, GFP_KERNEL);
 389         if (IS_ERR(bio)) {
 390                 ret = PTR_ERR(bio);
 391                 goto fail_free_rqd;
 392         }
 393         bio->bi_iter.bi_sector = 0; /* internal bio */
 394         bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
 395         rqd->bio = bio;
 396
 397         ret = pblk_alloc_w_rq(pblk, rqd, rq_ppas, pblk_end_io_write_meta);
 398         if (ret)
 399                 goto fail_free_bio;
 400
 401         for (i = 0; i < rqd->nr_ppas; ) {
 402                 spin_lock(&meta_line->lock);
 403                 paddr = __pblk_alloc_page(pblk, meta_line, rq_ppas);
 404                 spin_unlock(&meta_line->lock);
 405                 for (j = 0; j < rq_ppas; j++, i++, paddr++)
 406                         rqd->ppa_list[i] = addr_to_gen_ppa(pblk, paddr, id);
 407         }
 408
 409         rlun = &pblk->luns[pblk_ppa_to_pos(geo, rqd->ppa_list[0])];
 410         ret = down_timeout(&rlun->wr_sem, msecs_to_jiffies(5000));
 411         if (ret) {
 412                 pr_err("pblk: lun semaphore timed out (%d)\n", ret);
 413                 goto fail_free_bio;
 414         }
 415
 416         emeta->mem += rq_len;
 417         if (emeta->mem >= lm->emeta_len[0]) {
 418                 spin_lock(&l_mg->close_lock);
 419                 list_del(&meta_line->list);
 420                 WARN(!bitmap_full(meta_line->map_bitmap, lm->sec_per_line),
 421                                 "pblk: corrupt meta line %d\n", meta_line->id);
 422                 spin_unlock(&l_mg->close_lock);
 423         }
 424
 425         ret = pblk_submit_io(pblk, rqd);
 426         if (ret) {
 427                 pr_err("pblk: emeta I/O submission failed: %d\n", ret);
 428                 goto fail_rollback;
 429         }
 430
 431         return NVM_IO_OK;
 432
 433 fail_rollback:
 434         spin_lock(&l_mg->close_lock);
 435         pblk_dealloc_page(pblk, meta_line, rq_ppas);
 436         list_add(&meta_line->list, &meta_line->list);
 437         spin_unlock(&l_mg->close_lock);
 438 fail_free_bio:
 439         if (likely(l_mg->emeta_alloc_type == PBLK_VMALLOC_META))
 440                 bio_put(bio);
 441 fail_free_rqd:
 442         pblk_free_rqd(pblk, rqd, READ);
 443         return ret;
 444 }
 445
 446 static int pblk_sched_meta_io(struct pblk *pblk, struct ppa_addr *prev_list,
 447                                int prev_n)
 448 {
 449         struct pblk_line_meta *lm = &pblk->lm;
 450         struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 451         struct pblk_line *meta_line;
 452
 453         spin_lock(&l_mg->close_lock);
 454 retry:
 455         if (list_empty(&l_mg->emeta_list)) {
 456                 spin_unlock(&l_mg->close_lock);
 457                 return 0;
 458         }
 459         meta_line = list_first_entry(&l_mg->emeta_list, struct pblk_line, list);
 460         if (bitmap_full(meta_line->map_bitmap, lm->sec_per_line))
 461                 goto retry;
 462         spin_unlock(&l_mg->close_lock);
 463
 464         if (!pblk_valid_meta_ppa(pblk, meta_line, prev_list, prev_n))
 465                 return 0;
 466
 467         return pblk_submit_meta_io(pblk, meta_line);
 468 }
 469
 470 static int pblk_submit_io_set(struct pblk *pblk, struct nvm_rq *rqd)
 471 {
 472         struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
 473         struct ppa_addr erase_ppa;
 474         int err;
 475
 476         ppa_set_empty(&erase_ppa);
 477
 478         /* Assign lbas to ppas and populate request structure */
 479         err = pblk_setup_w_rq(pblk, rqd, c_ctx, &erase_ppa);
 480         if (err) {
 481                 pr_err("pblk: could not setup write request: %d\n", err);
 482                 return NVM_IO_ERR;
 483         }
 484
 485         if (likely(ppa_empty(erase_ppa))) {
 486                 /* Submit metadata write for previous data line */
 487                 err = pblk_sched_meta_io(pblk, rqd->ppa_list, rqd->nr_ppas);
 488                 if (err) {
 489                         pr_err("pblk: metadata I/O submission failed: %d", err);
 490                         return NVM_IO_ERR;
 491                 }
 492
 493                 /* Submit data write for current data line */
 494                 err = pblk_submit_io(pblk, rqd);
 495                 if (err) {
 496                         pr_err("pblk: data I/O submission failed: %d\n", err);
 497                         return NVM_IO_ERR;
 498                 }
 499         } else {
 500                 /* Submit data write for current data line */
 501                 err = pblk_submit_io(pblk, rqd);
 502                 if (err) {
 503                         pr_err("pblk: data I/O submission failed: %d\n", err);
 504                         return NVM_IO_ERR;
 505                 }
 506
 507                 /* Submit available erase for next data line */
 508                 if (pblk_blk_erase_async(pblk, erase_ppa)) {
 509                         struct pblk_line *e_line = pblk_line_get_erase(pblk);
 510                         struct nvm_tgt_dev *dev = pblk->dev;
 511                         struct nvm_geo *geo = &dev->geo;
 512                         int bit;
 513
 514                         atomic_inc(&e_line->left_eblks);
 515                         bit = pblk_ppa_to_pos(geo, erase_ppa);
 516                         WARN_ON(!test_and_clear_bit(bit, e_line->erase_bitmap));
 517                 }
 518         }
 519
 520         return NVM_IO_OK;
 521 }
 522
 523 static void pblk_free_write_rqd(struct pblk *pblk, struct nvm_rq *rqd)
 524 {
 525         struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
 526         struct bio *bio = rqd->bio;
 527
 528         if (c_ctx->nr_padded)
 529                 pblk_bio_free_pages(pblk, bio, rqd->nr_ppas, c_ctx->nr_padded);
 530 }
 531
 532 static int pblk_submit_write(struct pblk *pblk)
 533 {
 534         struct bio *bio;
 535         struct nvm_rq *rqd;
 536         unsigned int secs_avail, secs_to_sync, secs_to_com;
 537         unsigned int secs_to_flush;
 538         unsigned long pos;
 539
 540         /* If there are no sectors in the cache, flushes (bios without data)
 541          * will be cleared on the cache threads
 542          */
 543         secs_avail = pblk_rb_read_count(&pblk->rwb);
 544         if (!secs_avail)
 545                 return 1;
 546
 547         secs_to_flush = pblk_rb_sync_point_count(&pblk->rwb);
 548         if (!secs_to_flush && secs_avail < pblk->min_write_pgs)
 549                 return 1;
 550
 551         rqd = pblk_alloc_rqd(pblk, WRITE);
 552         if (IS_ERR(rqd)) {
 553                 pr_err("pblk: cannot allocate write req.\n");
 554                 return 1;
 555         }
 556
 557         bio = bio_alloc(GFP_KERNEL, pblk->max_write_pgs);
 558         if (!bio) {
 559                 pr_err("pblk: cannot allocate write bio\n");
 560                 goto fail_free_rqd;
 561         }
 562         bio->bi_iter.bi_sector = 0; /* internal bio */
 563         bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
 564         rqd->bio = bio;
 565
 566         secs_to_sync = pblk_calc_secs_to_sync(pblk, secs_avail, secs_to_flush);
 567         if (secs_to_sync > pblk->max_write_pgs) {
 568                 pr_err("pblk: bad buffer sync calculation\n");
 569                 goto fail_put_bio;
 570         }
 571
 572         secs_to_com = (secs_to_sync > secs_avail) ? secs_avail : secs_to_sync;
 573         pos = pblk_rb_read_commit(&pblk->rwb, secs_to_com);
 574
 575         if (pblk_rb_read_to_bio(&pblk->rwb, rqd, bio, pos, secs_to_sync,
 576                                                                 secs_avail)) {
 577                 pr_err("pblk: corrupted write bio\n");
 578                 goto fail_put_bio;
 579         }
 580
 581         if (pblk_submit_io_set(pblk, rqd))
 582                 goto fail_free_bio;
 583
 584 #ifdef CONFIG_NVM_DEBUG
 585         atomic_long_add(secs_to_sync, &pblk->sub_writes);
 586 #endif
 587
 588         return 0;
 589
 590 fail_free_bio:
 591         pblk_free_write_rqd(pblk, rqd);
 592 fail_put_bio:
 593         bio_put(bio);
 594 fail_free_rqd:
 595         pblk_free_rqd(pblk, rqd, WRITE);
 596
 597         return 1;
 598 }
 599
 600 int pblk_write_ts(void *data)
 601 {
 602         struct pblk *pblk = data;
 603
 604         while (!kthread_should_stop()) {
 605                 if (!pblk_submit_write(pblk))
 606                         continue;
 607                 set_current_state(TASK_INTERRUPTIBLE);
 608                 io_schedule();
 609         }
 610
 611         return 0;
 612 }