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         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         w_ctx.flags = flags;
  47         pblk_ppa_set_empty(&w_ctx.ppa);
  48
  49         for (i = 0; i < nr_entries; i++) {
  50                 void *data = bio_data(bio);
  51
  52                 w_ctx.lba = lba + i;
  53
  54                 pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + i);
  55                 pblk_rb_write_entry_user(&pblk->rwb, data, w_ctx, pos);
  56
  57                 bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
  58         }
  59
  60 #ifdef CONFIG_NVM_DEBUG
  61         atomic_long_add(nr_entries, &pblk->inflight_writes);
  62         atomic_long_add(nr_entries, &pblk->req_writes);
  63 #endif
  64
  65         pblk_rl_inserted(&pblk->rl, nr_entries);
  66
  67 out:
  68         pblk_write_should_kick(pblk);
  69         return ret;
  70 }
  71
  72 /*
  73  * On GC the incoming lbas are not necessarily sequential. Also, some of the
  74  * lbas might not be valid entries, which are marked as empty by the GC thread
  75  */
  76 int pblk_write_gc_to_cache(struct pblk *pblk, void *data, u64 *lba_list,
  77                            unsigned int nr_entries, unsigned int nr_rec_entries,
  78                            struct pblk_line *gc_line, unsigned long flags)
  79 {
  80         struct pblk_w_ctx w_ctx;
  81         unsigned int bpos, pos;
  82         int i, valid_entries;
  83
  84         /* Update the write buffer head (mem) with the entries that we can
  85          * write. The write in itself cannot fail, so there is no need to
  86          * rollback from here on.
  87          */
  88 retry:
  89         if (!pblk_rb_may_write_gc(&pblk->rwb, nr_rec_entries, &bpos)) {
  90                 io_schedule();
  91                 goto retry;
  92         }
  93
  94         w_ctx.flags = flags;
  95         pblk_ppa_set_empty(&w_ctx.ppa);
  96
  97         for (i = 0, valid_entries = 0; i < nr_entries; i++) {
  98                 if (lba_list[i] == ADDR_EMPTY)
  99                         continue;
 100
 101                 w_ctx.lba = lba_list[i];
 102
 103                 pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + valid_entries);
 104                 pblk_rb_write_entry_gc(&pblk->rwb, data, w_ctx, gc_line, pos);
 105
 106                 data += PBLK_EXPOSED_PAGE_SIZE;
 107                 valid_entries++;
 108         }
 109
 110         WARN_ONCE(nr_rec_entries != valid_entries,
 111                                         "pblk: inconsistent GC write\n");
 112
 113 #ifdef CONFIG_NVM_DEBUG
 114         atomic_long_add(valid_entries, &pblk->inflight_writes);
 115         atomic_long_add(valid_entries, &pblk->recov_gc_writes);
 116 #endif
 117
 118         pblk_write_should_kick(pblk);
 119         return NVM_IO_OK;
 120 }