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