LXR linux/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
  20int 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         */
  32retry:
  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
  67out:
  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 */
  76int 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         */
  88retry:
  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}
 121