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->close_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                                                                 pblk->close_wq);
 203
 204         bio_put(rqd->bio);
 205         pblk_free_rqd(pblk, rqd, READ);
 206 }
 207
 208 static int pblk_alloc_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
 209                            unsigned int nr_secs,
 210                            nvm_end_io_fn(*end_io))
 211 {
 212         struct nvm_tgt_dev *dev = pblk->dev;
 213
 214         /* Setup write request */
 215         rqd->opcode = NVM_OP_PWRITE;
 216         rqd->nr_ppas = nr_secs;
 217         rqd->flags = pblk_set_progr_mode(pblk, WRITE);
 218         rqd->private = pblk;
 219         rqd->end_io = end_io;
 220
 221         rqd->meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
 222                                                         &rqd->dma_meta_list);
 223         if (!rqd->meta_list)
 224                 return -ENOMEM;
 225
 226         if (unlikely(nr_secs == 1))
 227                 return 0;
 228
 229         rqd->ppa_list = rqd->meta_list + pblk_dma_meta_size;
 230         rqd->dma_ppa_list = rqd->dma_meta_list + pblk_dma_meta_size;
 231
 232         return 0;
 233 }
 234
 235 static int pblk_setup_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
 236                            struct pblk_c_ctx *c_ctx, struct ppa_addr *erase_ppa)
 237 {
 238         struct pblk_line_meta *lm = &pblk->lm;
 239         struct pblk_line *e_line = pblk_line_get_erase(pblk);
 240         unsigned int valid = c_ctx->nr_valid;
 241         unsigned int padded = c_ctx->nr_padded;
 242         unsigned int nr_secs = valid + padded;
 243         unsigned long *lun_bitmap;
 244         int ret = 0;
 245
 246         lun_bitmap = kzalloc(lm->lun_bitmap_len, GFP_KERNEL);
 247         if (!lun_bitmap)
 248                 return -ENOMEM;
 249         c_ctx->lun_bitmap = lun_bitmap;
 250
 251         ret = pblk_alloc_w_rq(pblk, rqd, nr_secs, pblk_end_io_write);
 252         if (ret) {
 253                 kfree(lun_bitmap);
 254                 return ret;
 255         }
 256
 257         if (likely(!atomic_read(&e_line->left_eblks) || !e_line))
 258                 pblk_map_rq(pblk, rqd, c_ctx->sentry, lun_bitmap, valid, 0);
 259         else
 260                 pblk_map_erase_rq(pblk, rqd, c_ctx->sentry, lun_bitmap,
 261                                                         valid, erase_ppa);
 262
 263         return 0;
 264 }
 265
 266 int pblk_setup_w_rec_rq(struct pblk *pblk, struct nvm_rq *rqd,
 267                         struct pblk_c_ctx *c_ctx)
 268 {
 269         struct pblk_line_meta *lm = &pblk->lm;
 270         unsigned long *lun_bitmap;
 271         int ret;
 272
 273         lun_bitmap = kzalloc(lm->lun_bitmap_len, GFP_KERNEL);
 274         if (!lun_bitmap)
 275                 return -ENOMEM;
 276
 277         c_ctx->lun_bitmap = lun_bitmap;
 278
 279         ret = pblk_alloc_w_rq(pblk, rqd, rqd->nr_ppas, pblk_end_io_write);
 280         if (ret)
 281                 return ret;
 282
 283         pblk_map_rq(pblk, rqd, c_ctx->sentry, lun_bitmap, c_ctx->nr_valid, 0);
 284
 285         rqd->ppa_status = (u64)0;
 286         rqd->flags = pblk_set_progr_mode(pblk, WRITE);
 287
 288         return ret;
 289 }
 290
 291 static int pblk_calc_secs_to_sync(struct pblk *pblk, unsigned int secs_avail,
 292                                   unsigned int secs_to_flush)
 293 {
 294         int secs_to_sync;
 295
 296         secs_to_sync = pblk_calc_secs(pblk, secs_avail, secs_to_flush);
 297
 298 #ifdef CONFIG_NVM_DEBUG
 299         if ((!secs_to_sync && secs_to_flush)
 300                         || (secs_to_sync < 0)
 301                         || (secs_to_sync > secs_avail && !secs_to_flush)) {
 302                 pr_err("pblk: bad sector calculation (a:%d,s:%d,f:%d)\n",
 303                                 secs_avail, secs_to_sync, secs_to_flush);
 304         }
 305 #endif
 306
 307         return secs_to_sync;
 308 }
 309
 310 static inline int pblk_valid_meta_ppa(struct pblk *pblk,
 311                                       struct pblk_line *meta_line,
 312                                       struct ppa_addr *ppa_list, int nr_ppas)
 313 {
 314         struct nvm_tgt_dev *dev = pblk->dev;
 315         struct nvm_geo *geo = &dev->geo;
 316         struct pblk_line *data_line;
 317         struct ppa_addr ppa, ppa_opt;
 318         u64 paddr;
 319         int i;
 320
 321         data_line = &pblk->lines[pblk_dev_ppa_to_line(ppa_list[0])];
 322         paddr = pblk_lookup_page(pblk, meta_line);
 323         ppa = addr_to_gen_ppa(pblk, paddr, 0);
 324
 325         if (test_bit(pblk_ppa_to_pos(geo, ppa), data_line->blk_bitmap))
 326                 return 1;
 327
 328         /* Schedule a metadata I/O that is half the distance from the data I/O
 329          * with regards to the number of LUNs forming the pblk instance. This
 330          * balances LUN conflicts across every I/O.
 331          *
 332          * When the LUN configuration changes (e.g., due to GC), this distance
 333          * can align, which would result on a LUN deadlock. In this case, modify
 334          * the distance to not be optimal, but allow metadata I/Os to succeed.
 335          */
 336         ppa_opt = addr_to_gen_ppa(pblk, paddr + data_line->meta_distance, 0);
 337         if (unlikely(ppa_opt.ppa == ppa.ppa)) {
 338                 data_line->meta_distance--;
 339                 return 0;
 340         }
 341
 342         for (i = 0; i < nr_ppas; i += pblk->min_write_pgs)
 343                 if (ppa_list[i].g.ch == ppa_opt.g.ch &&
 344                                         ppa_list[i].g.lun == ppa_opt.g.lun)
 345                         return 1;
 346
 347         if (test_bit(pblk_ppa_to_pos(geo, ppa_opt), data_line->blk_bitmap)) {
 348                 for (i = 0; i < nr_ppas; i += pblk->min_write_pgs)
 349                         if (ppa_list[i].g.ch == ppa.g.ch &&
 350                                                 ppa_list[i].g.lun == ppa.g.lun)
 351                                 return 0;
 352
 353                 return 1;
 354         }
 355
 356         return 0;
 357 }
 358
 359 int pblk_submit_meta_io(struct pblk *pblk, struct pblk_line *meta_line)
 360 {
 361         struct nvm_tgt_dev *dev = pblk->dev;
 362         struct nvm_geo *geo = &dev->geo;
 363         struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 364         struct pblk_line_meta *lm = &pblk->lm;
 365         struct pblk_emeta *emeta = meta_line->emeta;
 366         struct pblk_g_ctx *m_ctx;
 367         struct pblk_lun *rlun;
 368         struct bio *bio;
 369         struct nvm_rq *rqd;
 370         void *data;
 371         u64 paddr;
 372         int rq_ppas = pblk->min_write_pgs;
 373         int id = meta_line->id;
 374         int rq_len;
 375         int i, j;
 376         int ret;
 377
 378         rqd = pblk_alloc_rqd(pblk, READ);
 379         if (IS_ERR(rqd)) {
 380                 pr_err("pblk: cannot allocate write req.\n");
 381                 return PTR_ERR(rqd);
 382         }
 383         m_ctx = nvm_rq_to_pdu(rqd);
 384         m_ctx->private = meta_line;
 385
 386         rq_len = rq_ppas * geo->sec_size;
 387         data = ((void *)emeta->buf) + emeta->mem;
 388
 389         bio = pblk_bio_map_addr(pblk, data, rq_ppas, rq_len, GFP_KERNEL);
 390         if (IS_ERR(bio)) {
 391                 ret = PTR_ERR(bio);
 392                 goto fail_free_rqd;
 393         }
 394         bio->bi_iter.bi_sector = 0; /* internal bio */
 395         bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
 396         rqd->bio = bio;
 397
 398         ret = pblk_alloc_w_rq(pblk, rqd, rq_ppas, pblk_end_io_write_meta);
 399         if (ret)
 400                 goto fail_free_bio;
 401
 402         for (i = 0; i < rqd->nr_ppas; ) {
 403                 spin_lock(&meta_line->lock);
 404                 paddr = __pblk_alloc_page(pblk, meta_line, rq_ppas);
 405                 spin_unlock(&meta_line->lock);
 406                 for (j = 0; j < rq_ppas; j++, i++, paddr++)
 407                         rqd->ppa_list[i] = addr_to_gen_ppa(pblk, paddr, id);
 408         }
 409
 410         rlun = &pblk->luns[pblk_ppa_to_pos(geo, rqd->ppa_list[0])];
 411         ret = down_timeout(&rlun->wr_sem, msecs_to_jiffies(5000));
 412         if (ret) {
 413                 pr_err("pblk: lun semaphore timed out (%d)\n", ret);
 414                 goto fail_free_bio;
 415         }
 416
 417         emeta->mem += rq_len;
 418         if (emeta->mem >= lm->emeta_len[0]) {
 419                 spin_lock(&l_mg->close_lock);
 420                 list_del(&meta_line->list);
 421                 WARN(!bitmap_full(meta_line->map_bitmap, lm->sec_per_line),
 422                                 "pblk: corrupt meta line %d\n", meta_line->id);
 423                 spin_unlock(&l_mg->close_lock);
 424         }
 425
 426         ret = pblk_submit_io(pblk, rqd);
 427         if (ret) {
 428                 pr_err("pblk: emeta I/O submission failed: %d\n", ret);
 429                 goto fail_rollback;
 430         }
 431
 432         return NVM_IO_OK;
 433
 434 fail_rollback:
 435         spin_lock(&l_mg->close_lock);
 436         pblk_dealloc_page(pblk, meta_line, rq_ppas);
 437         list_add(&meta_line->list, &meta_line->list);
 438         spin_unlock(&l_mg->close_lock);
 439 fail_free_bio:
 440         if (likely(l_mg->emeta_alloc_type == PBLK_VMALLOC_META))
 441                 bio_put(bio);
 442 fail_free_rqd:
 443         pblk_free_rqd(pblk, rqd, READ);
 444         return ret;
 445 }
 446
 447 static int pblk_sched_meta_io(struct pblk *pblk, struct ppa_addr *prev_list,
 448                                int prev_n)
 449 {
 450         struct pblk_line_meta *lm = &pblk->lm;
 451         struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 452         struct pblk_line *meta_line;
 453
 454         spin_lock(&l_mg->close_lock);
 455 retry:
 456         if (list_empty(&l_mg->emeta_list)) {
 457                 spin_unlock(&l_mg->close_lock);
 458                 return 0;
 459         }
 460         meta_line = list_first_entry(&l_mg->emeta_list, struct pblk_line, list);
 461         if (bitmap_full(meta_line->map_bitmap, lm->sec_per_line))
 462                 goto retry;
 463         spin_unlock(&l_mg->close_lock);
 464
 465         if (!pblk_valid_meta_ppa(pblk, meta_line, prev_list, prev_n))
 466                 return 0;
 467
 468         return pblk_submit_meta_io(pblk, meta_line);
 469 }
 470
 471 static int pblk_submit_io_set(struct pblk *pblk, struct nvm_rq *rqd)
 472 {
 473         struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
 474         struct ppa_addr erase_ppa;
 475         int err;
 476
 477         ppa_set_empty(&erase_ppa);
 478
 479         /* Assign lbas to ppas and populate request structure */
 480         err = pblk_setup_w_rq(pblk, rqd, c_ctx, &erase_ppa);
 481         if (err) {
 482                 pr_err("pblk: could not setup write request: %d\n", err);
 483                 return NVM_IO_ERR;
 484         }
 485
 486         if (likely(ppa_empty(erase_ppa))) {
 487                 /* Submit metadata write for previous data line */
 488                 err = pblk_sched_meta_io(pblk, rqd->ppa_list, rqd->nr_ppas);
 489                 if (err) {
 490                         pr_err("pblk: metadata I/O submission failed: %d", err);
 491                         return NVM_IO_ERR;
 492                 }
 493
 494                 /* Submit data write for current data line */
 495                 err = pblk_submit_io(pblk, rqd);
 496                 if (err) {
 497                         pr_err("pblk: data I/O submission failed: %d\n", err);
 498                         return NVM_IO_ERR;
 499                 }
 500         } else {
 501                 /* Submit data write for current data line */
 502                 err = pblk_submit_io(pblk, rqd);
 503                 if (err) {
 504                         pr_err("pblk: data I/O submission failed: %d\n", err);
 505                         return NVM_IO_ERR;
 506                 }
 507
 508                 /* Submit available erase for next data line */
 509                 if (pblk_blk_erase_async(pblk, erase_ppa)) {
 510                         struct pblk_line *e_line = pblk_line_get_erase(pblk);
 511                         struct nvm_tgt_dev *dev = pblk->dev;
 512                         struct nvm_geo *geo = &dev->geo;
 513                         int bit;
 514
 515                         atomic_inc(&e_line->left_eblks);
 516                         bit = pblk_ppa_to_pos(geo, erase_ppa);
 517                         WARN_ON(!test_and_clear_bit(bit, e_line->erase_bitmap));
 518                 }
 519         }
 520
 521         return NVM_IO_OK;
 522 }
 523
 524 static void pblk_free_write_rqd(struct pblk *pblk, struct nvm_rq *rqd)
 525 {
 526         struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
 527         struct bio *bio = rqd->bio;
 528
 529         if (c_ctx->nr_padded)
 530                 pblk_bio_free_pages(pblk, bio, rqd->nr_ppas, c_ctx->nr_padded);
 531 }
 532
 533 static int pblk_submit_write(struct pblk *pblk)
 534 {
 535         struct bio *bio;
 536         struct nvm_rq *rqd;
 537         unsigned int secs_avail, secs_to_sync, secs_to_com;
 538         unsigned int secs_to_flush;
 539         unsigned long pos;
 540
 541         /* If there are no sectors in the cache, flushes (bios without data)
 542          * will be cleared on the cache threads
 543          */
 544         secs_avail = pblk_rb_read_count(&pblk->rwb);
 545         if (!secs_avail)
 546                 return 1;
 547
 548         secs_to_flush = pblk_rb_sync_point_count(&pblk->rwb);
 549         if (!secs_to_flush && secs_avail < pblk->min_write_pgs)
 550                 return 1;
 551
 552         rqd = pblk_alloc_rqd(pblk, WRITE);
 553         if (IS_ERR(rqd)) {
 554                 pr_err("pblk: cannot allocate write req.\n");
 555                 return 1;
 556         }
 557
 558         bio = bio_alloc(GFP_KERNEL, pblk->max_write_pgs);
 559         if (!bio) {
 560                 pr_err("pblk: cannot allocate write bio\n");
 561                 goto fail_free_rqd;
 562         }
 563         bio->bi_iter.bi_sector = 0; /* internal bio */
 564         bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
 565         rqd->bio = bio;
 566
 567         secs_to_sync = pblk_calc_secs_to_sync(pblk, secs_avail, secs_to_flush);
 568         if (secs_to_sync > pblk->max_write_pgs) {
 569                 pr_err("pblk: bad buffer sync calculation\n");
 570                 goto fail_put_bio;
 571         }
 572
 573         secs_to_com = (secs_to_sync > secs_avail) ? secs_avail : secs_to_sync;
 574         pos = pblk_rb_read_commit(&pblk->rwb, secs_to_com);
 575
 576         if (pblk_rb_read_to_bio(&pblk->rwb, rqd, bio, pos, secs_to_sync,
 577                                                                 secs_avail)) {
 578                 pr_err("pblk: corrupted write bio\n");
 579                 goto fail_put_bio;
 580         }
 581
 582         if (pblk_submit_io_set(pblk, rqd))
 583                 goto fail_free_bio;
 584
 585 #ifdef CONFIG_NVM_DEBUG
 586         atomic_long_add(secs_to_sync, &pblk->sub_writes);
 587 #endif
 588
 589         return 0;
 590
 591 fail_free_bio:
 592         pblk_free_write_rqd(pblk, rqd);
 593 fail_put_bio:
 594         bio_put(bio);
 595 fail_free_rqd:
 596         pblk_free_rqd(pblk, rqd, WRITE);
 597
 598         return 1;
 599 }
 600
 601 int pblk_write_ts(void *data)
 602 {
 603         struct pblk *pblk = data;
 604
 605         while (!kthread_should_stop()) {
 606                 if (!pblk_submit_write(pblk))
 607                         continue;
 608                 set_current_state(TASK_INTERRUPTIBLE);
 609                 io_schedule();
 610         }
 611
 612         return 0;
 613 }