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         atomic_dec(&pblk->inflight_io);
 175 }
 176
 177 static void pblk_end_io_write_meta(struct nvm_rq *rqd)
 178 {
 179         struct pblk *pblk = rqd->private;
 180         struct nvm_tgt_dev *dev = pblk->dev;
 181         struct nvm_geo *geo = &dev->geo;
 182         struct pblk_g_ctx *m_ctx = nvm_rq_to_pdu(rqd);
 183         struct pblk_line *line = m_ctx->private;
 184         struct pblk_emeta *emeta = line->emeta;
 185         int pos = pblk_ppa_to_pos(geo, rqd->ppa_list[0]);
 186         struct pblk_lun *rlun = &pblk->luns[pos];
 187         int sync;
 188
 189         up(&rlun->wr_sem);
 190
 191         if (rqd->error) {
 192                 pblk_log_write_err(pblk, rqd);
 193                 pr_err("pblk: metadata I/O failed. Line %d\n", line->id);
 194         }
 195 #ifdef CONFIG_NVM_DEBUG
 196         else
 197                 WARN_ONCE(rqd->bio->bi_status, "pblk: corrupted write error\n");
 198 #endif
 199
 200         sync = atomic_add_return(rqd->nr_ppas, &emeta->sync);
 201         if (sync == emeta->nr_entries)
 202                 pblk_line_run_ws(pblk, line, NULL, pblk_line_close_ws,
 203                                                                 pblk->close_wq);
 204
 205         bio_put(rqd->bio);
 206         pblk_free_rqd(pblk, rqd, READ);
 207
 208         atomic_dec(&pblk->inflight_io);
 209 }
 210
 211 static int pblk_alloc_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
 212                            unsigned int nr_secs,
 213                            nvm_end_io_fn(*end_io))
 214 {
 215         struct nvm_tgt_dev *dev = pblk->dev;
 216
 217         /* Setup write request */
 218         rqd->opcode = NVM_OP_PWRITE;
 219         rqd->nr_ppas = nr_secs;
 220         rqd->flags = pblk_set_progr_mode(pblk, WRITE);
 221         rqd->private = pblk;
 222         rqd->end_io = end_io;
 223
 224         rqd->meta_list = nvm_dev_dma_alloc(dev->parent, GFP_KERNEL,
 225                                                         &rqd->dma_meta_list);
 226         if (!rqd->meta_list)
 227                 return -ENOMEM;
 228
 229         if (unlikely(nr_secs == 1))
 230                 return 0;
 231
 232         rqd->ppa_list = rqd->meta_list + pblk_dma_meta_size;
 233         rqd->dma_ppa_list = rqd->dma_meta_list + pblk_dma_meta_size;
 234
 235         return 0;
 236 }
 237
 238 static int pblk_setup_w_rq(struct pblk *pblk, struct nvm_rq *rqd,
 239                            struct pblk_c_ctx *c_ctx, struct ppa_addr *erase_ppa)
 240 {
 241         struct pblk_line_meta *lm = &pblk->lm;
 242         struct pblk_line *e_line = pblk_line_get_erase(pblk);
 243         unsigned int valid = c_ctx->nr_valid;
 244         unsigned int padded = c_ctx->nr_padded;
 245         unsigned int nr_secs = valid + padded;
 246         unsigned long *lun_bitmap;
 247         int ret = 0;
 248
 249         lun_bitmap = kzalloc(lm->lun_bitmap_len, GFP_KERNEL);
 250         if (!lun_bitmap)
 251                 return -ENOMEM;
 252         c_ctx->lun_bitmap = lun_bitmap;
 253
 254         ret = pblk_alloc_w_rq(pblk, rqd, nr_secs, pblk_end_io_write);
 255         if (ret) {
 256                 kfree(lun_bitmap);
 257                 return ret;
 258         }
 259
 260         if (likely(!e_line || !atomic_read(&e_line->left_eblks)))
 261                 pblk_map_rq(pblk, rqd, c_ctx->sentry, lun_bitmap, valid, 0);
 262         else
 263                 pblk_map_erase_rq(pblk, rqd, c_ctx->sentry, lun_bitmap,
 264                                                         valid, erase_ppa);
 265
 266         return 0;
 267 }
 268
 269 int pblk_setup_w_rec_rq(struct pblk *pblk, struct nvm_rq *rqd,
 270                         struct pblk_c_ctx *c_ctx)
 271 {
 272         struct pblk_line_meta *lm = &pblk->lm;
 273         unsigned long *lun_bitmap;
 274         int ret;
 275
 276         lun_bitmap = kzalloc(lm->lun_bitmap_len, GFP_KERNEL);
 277         if (!lun_bitmap)
 278                 return -ENOMEM;
 279
 280         c_ctx->lun_bitmap = lun_bitmap;
 281
 282         ret = pblk_alloc_w_rq(pblk, rqd, rqd->nr_ppas, pblk_end_io_write);
 283         if (ret)
 284                 return ret;
 285
 286         pblk_map_rq(pblk, rqd, c_ctx->sentry, lun_bitmap, c_ctx->nr_valid, 0);
 287
 288         rqd->ppa_status = (u64)0;
 289         rqd->flags = pblk_set_progr_mode(pblk, WRITE);
 290
 291         return ret;
 292 }
 293
 294 static int pblk_calc_secs_to_sync(struct pblk *pblk, unsigned int secs_avail,
 295                                   unsigned int secs_to_flush)
 296 {
 297         int secs_to_sync;
 298
 299         secs_to_sync = pblk_calc_secs(pblk, secs_avail, secs_to_flush);
 300
 301 #ifdef CONFIG_NVM_DEBUG
 302         if ((!secs_to_sync && secs_to_flush)
 303                         || (secs_to_sync < 0)
 304                         || (secs_to_sync > secs_avail && !secs_to_flush)) {
 305                 pr_err("pblk: bad sector calculation (a:%d,s:%d,f:%d)\n",
 306                                 secs_avail, secs_to_sync, secs_to_flush);
 307         }
 308 #endif
 309
 310         return secs_to_sync;
 311 }
 312
 313 static inline int pblk_valid_meta_ppa(struct pblk *pblk,
 314                                       struct pblk_line *meta_line,
 315                                       struct ppa_addr *ppa_list, int nr_ppas)
 316 {
 317         struct nvm_tgt_dev *dev = pblk->dev;
 318         struct nvm_geo *geo = &dev->geo;
 319         struct pblk_line *data_line;
 320         struct ppa_addr ppa, ppa_opt;
 321         u64 paddr;
 322         int i;
 323
 324         data_line = &pblk->lines[pblk_dev_ppa_to_line(ppa_list[0])];
 325         paddr = pblk_lookup_page(pblk, meta_line);
 326         ppa = addr_to_gen_ppa(pblk, paddr, 0);
 327
 328         if (test_bit(pblk_ppa_to_pos(geo, ppa), data_line->blk_bitmap))
 329                 return 1;
 330
 331         /* Schedule a metadata I/O that is half the distance from the data I/O
 332          * with regards to the number of LUNs forming the pblk instance. This
 333          * balances LUN conflicts across every I/O.
 334          *
 335          * When the LUN configuration changes (e.g., due to GC), this distance
 336          * can align, which would result on a LUN deadlock. In this case, modify
 337          * the distance to not be optimal, but allow metadata I/Os to succeed.
 338          */
 339         ppa_opt = addr_to_gen_ppa(pblk, paddr + data_line->meta_distance, 0);
 340         if (unlikely(ppa_opt.ppa == ppa.ppa)) {
 341                 data_line->meta_distance--;
 342                 return 0;
 343         }
 344
 345         for (i = 0; i < nr_ppas; i += pblk->min_write_pgs)
 346                 if (ppa_list[i].g.ch == ppa_opt.g.ch &&
 347                                         ppa_list[i].g.lun == ppa_opt.g.lun)
 348                         return 1;
 349
 350         if (test_bit(pblk_ppa_to_pos(geo, ppa_opt), data_line->blk_bitmap)) {
 351                 for (i = 0; i < nr_ppas; i += pblk->min_write_pgs)
 352                         if (ppa_list[i].g.ch == ppa.g.ch &&
 353                                                 ppa_list[i].g.lun == ppa.g.lun)
 354                                 return 0;
 355
 356                 return 1;
 357         }
 358
 359         return 0;
 360 }
 361
 362 int pblk_submit_meta_io(struct pblk *pblk, struct pblk_line *meta_line)
 363 {
 364         struct nvm_tgt_dev *dev = pblk->dev;
 365         struct nvm_geo *geo = &dev->geo;
 366         struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 367         struct pblk_line_meta *lm = &pblk->lm;
 368         struct pblk_emeta *emeta = meta_line->emeta;
 369         struct pblk_g_ctx *m_ctx;
 370         struct pblk_lun *rlun;
 371         struct bio *bio;
 372         struct nvm_rq *rqd;
 373         void *data;
 374         u64 paddr;
 375         int rq_ppas = pblk->min_write_pgs;
 376         int id = meta_line->id;
 377         int rq_len;
 378         int i, j;
 379         int ret;
 380
 381         rqd = pblk_alloc_rqd(pblk, READ);
 382         if (IS_ERR(rqd)) {
 383                 pr_err("pblk: cannot allocate write req.\n");
 384                 return PTR_ERR(rqd);
 385         }
 386         m_ctx = nvm_rq_to_pdu(rqd);
 387         m_ctx->private = meta_line;
 388
 389         rq_len = rq_ppas * geo->sec_size;
 390         data = ((void *)emeta->buf) + emeta->mem;
 391
 392         bio = pblk_bio_map_addr(pblk, data, rq_ppas, rq_len,
 393                                         l_mg->emeta_alloc_type, GFP_KERNEL);
 394         if (IS_ERR(bio)) {
 395                 ret = PTR_ERR(bio);
 396                 goto fail_free_rqd;
 397         }
 398         bio->bi_iter.bi_sector = 0; /* internal bio */
 399         bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
 400         rqd->bio = bio;
 401
 402         ret = pblk_alloc_w_rq(pblk, rqd, rq_ppas, pblk_end_io_write_meta);
 403         if (ret)
 404                 goto fail_free_bio;
 405
 406         for (i = 0; i < rqd->nr_ppas; ) {
 407                 spin_lock(&meta_line->lock);
 408                 paddr = __pblk_alloc_page(pblk, meta_line, rq_ppas);
 409                 spin_unlock(&meta_line->lock);
 410                 for (j = 0; j < rq_ppas; j++, i++, paddr++)
 411                         rqd->ppa_list[i] = addr_to_gen_ppa(pblk, paddr, id);
 412         }
 413
 414         rlun = &pblk->luns[pblk_ppa_to_pos(geo, rqd->ppa_list[0])];
 415         ret = down_timeout(&rlun->wr_sem, msecs_to_jiffies(5000));
 416         if (ret) {
 417                 pr_err("pblk: lun semaphore timed out (%d)\n", ret);
 418                 goto fail_free_bio;
 419         }
 420
 421         emeta->mem += rq_len;
 422         if (emeta->mem >= lm->emeta_len[0]) {
 423                 spin_lock(&l_mg->close_lock);
 424                 list_del(&meta_line->list);
 425                 WARN(!bitmap_full(meta_line->map_bitmap, lm->sec_per_line),
 426                                 "pblk: corrupt meta line %d\n", meta_line->id);
 427                 spin_unlock(&l_mg->close_lock);
 428         }
 429
 430         ret = pblk_submit_io(pblk, rqd);
 431         if (ret) {
 432                 pr_err("pblk: emeta I/O submission failed: %d\n", ret);
 433                 goto fail_rollback;
 434         }
 435
 436         return NVM_IO_OK;
 437
 438 fail_rollback:
 439         spin_lock(&l_mg->close_lock);
 440         pblk_dealloc_page(pblk, meta_line, rq_ppas);
 441         list_add(&meta_line->list, &meta_line->list);
 442         spin_unlock(&l_mg->close_lock);
 443 fail_free_bio:
 444         if (likely(l_mg->emeta_alloc_type == PBLK_VMALLOC_META))
 445                 bio_put(bio);
 446 fail_free_rqd:
 447         pblk_free_rqd(pblk, rqd, READ);
 448         return ret;
 449 }
 450
 451 static int pblk_sched_meta_io(struct pblk *pblk, struct ppa_addr *prev_list,
 452                                int prev_n)
 453 {
 454         struct pblk_line_meta *lm = &pblk->lm;
 455         struct pblk_line_mgmt *l_mg = &pblk->l_mg;
 456         struct pblk_line *meta_line;
 457
 458         spin_lock(&l_mg->close_lock);
 459 retry:
 460         if (list_empty(&l_mg->emeta_list)) {
 461                 spin_unlock(&l_mg->close_lock);
 462                 return 0;
 463         }
 464         meta_line = list_first_entry(&l_mg->emeta_list, struct pblk_line, list);
 465         if (bitmap_full(meta_line->map_bitmap, lm->sec_per_line))
 466                 goto retry;
 467         spin_unlock(&l_mg->close_lock);
 468
 469         if (!pblk_valid_meta_ppa(pblk, meta_line, prev_list, prev_n))
 470                 return 0;
 471
 472         return pblk_submit_meta_io(pblk, meta_line);
 473 }
 474
 475 static int pblk_submit_io_set(struct pblk *pblk, struct nvm_rq *rqd)
 476 {
 477         struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
 478         struct ppa_addr erase_ppa;
 479         int err;
 480
 481         ppa_set_empty(&erase_ppa);
 482
 483         /* Assign lbas to ppas and populate request structure */
 484         err = pblk_setup_w_rq(pblk, rqd, c_ctx, &erase_ppa);
 485         if (err) {
 486                 pr_err("pblk: could not setup write request: %d\n", err);
 487                 return NVM_IO_ERR;
 488         }
 489
 490         if (likely(ppa_empty(erase_ppa))) {
 491                 /* Submit metadata write for previous data line */
 492                 err = pblk_sched_meta_io(pblk, rqd->ppa_list, rqd->nr_ppas);
 493                 if (err) {
 494                         pr_err("pblk: metadata I/O submission failed: %d", err);
 495                         return NVM_IO_ERR;
 496                 }
 497
 498                 /* Submit data write for current data line */
 499                 err = pblk_submit_io(pblk, rqd);
 500                 if (err) {
 501                         pr_err("pblk: data I/O submission failed: %d\n", err);
 502                         return NVM_IO_ERR;
 503                 }
 504         } else {
 505                 /* Submit data write for current data line */
 506                 err = pblk_submit_io(pblk, rqd);
 507                 if (err) {
 508                         pr_err("pblk: data I/O submission failed: %d\n", err);
 509                         return NVM_IO_ERR;
 510                 }
 511
 512                 /* Submit available erase for next data line */
 513                 if (pblk_blk_erase_async(pblk, erase_ppa)) {
 514                         struct pblk_line *e_line = pblk_line_get_erase(pblk);
 515                         struct nvm_tgt_dev *dev = pblk->dev;
 516                         struct nvm_geo *geo = &dev->geo;
 517                         int bit;
 518
 519                         atomic_inc(&e_line->left_eblks);
 520                         bit = pblk_ppa_to_pos(geo, erase_ppa);
 521                         WARN_ON(!test_and_clear_bit(bit, e_line->erase_bitmap));
 522                 }
 523         }
 524
 525         return NVM_IO_OK;
 526 }
 527
 528 static void pblk_free_write_rqd(struct pblk *pblk, struct nvm_rq *rqd)
 529 {
 530         struct pblk_c_ctx *c_ctx = nvm_rq_to_pdu(rqd);
 531         struct bio *bio = rqd->bio;
 532
 533         if (c_ctx->nr_padded)
 534                 pblk_bio_free_pages(pblk, bio, rqd->nr_ppas, c_ctx->nr_padded);
 535 }
 536
 537 static int pblk_submit_write(struct pblk *pblk)
 538 {
 539         struct bio *bio;
 540         struct nvm_rq *rqd;
 541         unsigned int secs_avail, secs_to_sync, secs_to_com;
 542         unsigned int secs_to_flush;
 543         unsigned long pos;
 544
 545         /* If there are no sectors in the cache, flushes (bios without data)
 546          * will be cleared on the cache threads
 547          */
 548         secs_avail = pblk_rb_read_count(&pblk->rwb);
 549         if (!secs_avail)
 550                 return 1;
 551
 552         secs_to_flush = pblk_rb_sync_point_count(&pblk->rwb);
 553         if (!secs_to_flush && secs_avail < pblk->min_write_pgs)
 554                 return 1;
 555
 556         rqd = pblk_alloc_rqd(pblk, WRITE);
 557         if (IS_ERR(rqd)) {
 558                 pr_err("pblk: cannot allocate write req.\n");
 559                 return 1;
 560         }
 561
 562         bio = bio_alloc(GFP_KERNEL, pblk->max_write_pgs);
 563         if (!bio) {
 564                 pr_err("pblk: cannot allocate write bio\n");
 565                 goto fail_free_rqd;
 566         }
 567         bio->bi_iter.bi_sector = 0; /* internal bio */
 568         bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
 569         rqd->bio = bio;
 570
 571         secs_to_sync = pblk_calc_secs_to_sync(pblk, secs_avail, secs_to_flush);
 572         if (secs_to_sync > pblk->max_write_pgs) {
 573                 pr_err("pblk: bad buffer sync calculation\n");
 574                 goto fail_put_bio;
 575         }
 576
 577         secs_to_com = (secs_to_sync > secs_avail) ? secs_avail : secs_to_sync;
 578         pos = pblk_rb_read_commit(&pblk->rwb, secs_to_com);
 579
 580         if (pblk_rb_read_to_bio(&pblk->rwb, rqd, bio, pos, secs_to_sync,
 581                                                                 secs_avail)) {
 582                 pr_err("pblk: corrupted write bio\n");
 583                 goto fail_put_bio;
 584         }
 585
 586         if (pblk_submit_io_set(pblk, rqd))
 587                 goto fail_free_bio;
 588
 589 #ifdef CONFIG_NVM_DEBUG
 590         atomic_long_add(secs_to_sync, &pblk->sub_writes);
 591 #endif
 592
 593         return 0;
 594
 595 fail_free_bio:
 596         pblk_free_write_rqd(pblk, rqd);
 597 fail_put_bio:
 598         bio_put(bio);
 599 fail_free_rqd:
 600         pblk_free_rqd(pblk, rqd, WRITE);
 601
 602         return 1;
 603 }
 604
 605 int pblk_write_ts(void *data)
 606 {
 607         struct pblk *pblk = data;
 608
 609         while (!kthread_should_stop()) {
 610                 if (!pblk_submit_write(pblk))
 611                         continue;
 612                 set_current_state(TASK_INTERRUPTIBLE);
 613                 io_schedule();
 614         }
 615
 616         return 0;
 617 }