drivers/lightnvm/pblk-cache.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-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         if (ret == NVM_IO_REQUEUE) {
  35                 io_schedule();
  36                 goto retry;
  37         }
  38
  39         if (unlikely(!bio_has_data(bio)))
  40                 goto out;
  41
  42         w_ctx.flags = flags;
  43         pblk_ppa_set_empty(&w_ctx.ppa);
  44
  45         for (i = 0; i < nr_entries; i++) {
  46                 void *data = bio_data(bio);
  47
  48                 w_ctx.lba = lba + i;
  49
  50                 pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + i);
  51                 pblk_rb_write_entry_user(&pblk->rwb, data, w_ctx, pos);
  52
  53                 bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
  54         }
  55
  56 #ifdef CONFIG_NVM_DEBUG
  57         atomic_long_add(nr_entries, &pblk->inflight_writes);
  58         atomic_long_add(nr_entries, &pblk->req_writes);
  59 #endif
  60
  61 out:
  62         pblk_write_should_kick(pblk);
  63         return ret;
  64 }
  65
  66 /*
  67  * On GC the incoming lbas are not necessarily sequential. Also, some of the
  68  * lbas might not be valid entries, which are marked as empty by the GC thread
  69  */
  70 int pblk_write_gc_to_cache(struct pblk *pblk, void *data, u64 *lba_list,
  71                            unsigned int nr_entries, unsigned int nr_rec_entries,
  72                            struct pblk_line *gc_line, unsigned long flags)
  73 {
  74         struct pblk_w_ctx w_ctx;
  75         unsigned int bpos, pos;
  76         int i, valid_entries;
  77
  78         /* Update the write buffer head (mem) with the entries that we can
  79          * write. The write in itself cannot fail, so there is no need to
  80          * rollback from here on.
  81          */
  82 retry:
  83         if (!pblk_rb_may_write_gc(&pblk->rwb, nr_rec_entries, &bpos)) {
  84                 io_schedule();
  85                 goto retry;
  86         }
  87
  88         w_ctx.flags = flags;
  89         pblk_ppa_set_empty(&w_ctx.ppa);
  90
  91         for (i = 0, valid_entries = 0; i < nr_entries; i++) {
  92                 if (lba_list[i] == ADDR_EMPTY)
  93                         continue;
  94
  95                 w_ctx.lba = lba_list[i];
  96
  97                 pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + valid_entries);
  98                 pblk_rb_write_entry_gc(&pblk->rwb, data, w_ctx, gc_line, pos);
  99
 100                 data += PBLK_EXPOSED_PAGE_SIZE;
 101                 valid_entries++;
 102         }
 103
 104         WARN_ONCE(nr_rec_entries != valid_entries,
 105                                         "pblk: inconsistent GC write\n");
 106
 107 #ifdef CONFIG_NVM_DEBUG
 108         atomic_long_add(valid_entries, &pblk->inflight_writes);
 109         atomic_long_add(valid_entries, &pblk->recov_gc_writes);
 110 #endif
 111
 112         pblk_write_should_kick(pblk);
 113         return NVM_IO_OK;
 114 }