drivers/lightnvm/pblk-cache.c

   1 /*
   2  * Copyright (C) 2016 CNEX Labs
   3  * Initial release: Javier Gonzalez <[email protected]>
   4  *                  Matias Bjorling <[email protected]>
   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-cache.c - pblk's write cache
  16  */
  17
  18 #include "pblk.h"
  19
  20 int pblk_write_to_cache(struct pblk *pblk, struct bio *bio, unsigned long flags)
  21 {
  22         struct pblk_w_ctx w_ctx;
  23         sector_t lba = pblk_get_lba(bio);
  24         unsigned int bpos, pos;
  25         int nr_entries = pblk_get_secs(bio);
  26         int i, ret;
  27
  28         /* Update the write buffer head (mem) with the entries that we can
  29          * write. The write in itself cannot fail, so there is no need to
  30          * rollback from here on.
  31          */
  32 retry:
  33         ret = pblk_rb_may_write_user(&pblk->rwb, bio, nr_entries, &bpos);
  34         switch (ret) {
  35         case NVM_IO_REQUEUE:
  36                 io_schedule();
  37                 goto retry;
  38         case NVM_IO_ERR:
  39                 pblk_pipeline_stop(pblk);
  40                 goto out;
  41         }
  42
  43         if (unlikely(!bio_has_data(bio)))
  44                 goto out;
  45
  46         pblk_ppa_set_empty(&w_ctx.ppa);
  47         w_ctx.flags = flags;
  48         if (bio->bi_opf & REQ_PREFLUSH)
  49                 w_ctx.flags |= PBLK_FLUSH_ENTRY;
  50
  51         for (i = 0; i < nr_entries; i++) {
  52                 void *data = bio_data(bio);
  53
  54                 w_ctx.lba = lba + i;
  55
  56                 pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + i);
  57                 pblk_rb_write_entry_user(&pblk->rwb, data, w_ctx, pos);
  58
  59                 bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
  60         }
  61
  62 #ifdef CONFIG_NVM_DEBUG
  63         atomic_long_add(nr_entries, &pblk->inflight_writes);
  64         atomic_long_add(nr_entries, &pblk->req_writes);
  65 #endif
  66
  67         pblk_rl_inserted(&pblk->rl, nr_entries);
  68
  69 out:
  70         pblk_write_should_kick(pblk);
  71         return ret;
  72 }
  73
  74 /*
  75  * On GC the incoming lbas are not necessarily sequential. Also, some of the
  76  * lbas might not be valid entries, which are marked as empty by the GC thread
  77  */
  78 int pblk_write_gc_to_cache(struct pblk *pblk, struct pblk_gc_rq *gc_rq)
  79 {
  80         struct pblk_w_ctx w_ctx;
  81         unsigned int bpos, pos;
  82         void *data = gc_rq->data;
  83         int i, valid_entries;
  84
  85         /* Update the write buffer head (mem) with the entries that we can
  86          * write. The write in itself cannot fail, so there is no need to
  87          * rollback from here on.
  88          */
  89 retry:
  90         if (!pblk_rb_may_write_gc(&pblk->rwb, gc_rq->secs_to_gc, &bpos)) {
  91                 io_schedule();
  92                 goto retry;
  93         }
  94
  95         w_ctx.flags = PBLK_IOTYPE_GC;
  96         pblk_ppa_set_empty(&w_ctx.ppa);
  97
  98         for (i = 0, valid_entries = 0; i < gc_rq->nr_secs; i++) {
  99                 if (gc_rq->lba_list[i] == ADDR_EMPTY)
 100                         continue;
 101
 102                 w_ctx.lba = gc_rq->lba_list[i];
 103
 104                 pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + valid_entries);
 105                 pblk_rb_write_entry_gc(&pblk->rwb, data, w_ctx, gc_rq->line,
 106                                                 gc_rq->paddr_list[i], pos);
 107
 108                 data += PBLK_EXPOSED_PAGE_SIZE;
 109                 valid_entries++;
 110         }
 111
 112         WARN_ONCE(gc_rq->secs_to_gc != valid_entries,
 113                                         "pblk: inconsistent GC write\n");
 114
 115 #ifdef CONFIG_NVM_DEBUG
 116         atomic_long_add(valid_entries, &pblk->inflight_writes);
 117         atomic_long_add(valid_entries, &pblk->recov_gc_writes);
 118 #endif
 119
 120         pblk_write_should_kick(pblk);
 121         return NVM_IO_OK;
 122 }