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 request_queue *q = pblk->dev->q;
  23         struct pblk_w_ctx w_ctx;
  24         sector_t lba = pblk_get_lba(bio);
  25         unsigned long start_time = jiffies;
  26         unsigned int bpos, pos;
  27         int nr_entries = pblk_get_secs(bio);
  28         int i, ret;
  29
  30         generic_start_io_acct(q, REQ_OP_WRITE, bio_sectors(bio),
  31                               &pblk->disk->part0);
  32
  33         /* Update the write buffer head (mem) with the entries that we can
  34          * write. The write in itself cannot fail, so there is no need to
  35          * rollback from here on.
  36          */
  37 retry:
  38         ret = pblk_rb_may_write_user(&pblk->rwb, bio, nr_entries, &bpos);
  39         switch (ret) {
  40         case NVM_IO_REQUEUE:
  41                 io_schedule();
  42                 goto retry;
  43         case NVM_IO_ERR:
  44                 pblk_pipeline_stop(pblk);
  45                 goto out;
  46         }
  47
  48         pblk_ppa_set_empty(&w_ctx.ppa);
  49         w_ctx.flags = flags;
  50         if (bio->bi_opf & REQ_PREFLUSH) {
  51                 w_ctx.flags |= PBLK_FLUSH_ENTRY;
  52                 pblk_write_kick(pblk);
  53         }
  54
  55         if (unlikely(!bio_has_data(bio)))
  56                 goto out;
  57
  58         for (i = 0; i < nr_entries; i++) {
  59                 void *data = bio_data(bio);
  60
  61                 w_ctx.lba = lba + i;
  62
  63                 pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + i);
  64                 pblk_rb_write_entry_user(&pblk->rwb, data, w_ctx, pos);
  65
  66                 bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
  67         }
  68
  69         atomic64_add(nr_entries, &pblk->user_wa);
  70
  71 #ifdef CONFIG_NVM_PBLK_DEBUG
  72         atomic_long_add(nr_entries, &pblk->inflight_writes);
  73         atomic_long_add(nr_entries, &pblk->req_writes);
  74 #endif
  75
  76         pblk_rl_inserted(&pblk->rl, nr_entries);
  77
  78 out:
  79         generic_end_io_acct(q, REQ_OP_WRITE, &pblk->disk->part0, start_time);
  80         pblk_write_should_kick(pblk);
  81         return ret;
  82 }
  83
  84 /*
  85  * On GC the incoming lbas are not necessarily sequential. Also, some of the
  86  * lbas might not be valid entries, which are marked as empty by the GC thread
  87  */
  88 int pblk_write_gc_to_cache(struct pblk *pblk, struct pblk_gc_rq *gc_rq)
  89 {
  90         struct pblk_w_ctx w_ctx;
  91         unsigned int bpos, pos;
  92         void *data = gc_rq->data;
  93         int i, valid_entries;
  94
  95         /* Update the write buffer head (mem) with the entries that we can
  96          * write. The write in itself cannot fail, so there is no need to
  97          * rollback from here on.
  98          */
  99 retry:
 100         if (!pblk_rb_may_write_gc(&pblk->rwb, gc_rq->secs_to_gc, &bpos)) {
 101                 io_schedule();
 102                 goto retry;
 103         }
 104
 105         w_ctx.flags = PBLK_IOTYPE_GC;
 106         pblk_ppa_set_empty(&w_ctx.ppa);
 107
 108         for (i = 0, valid_entries = 0; i < gc_rq->nr_secs; i++) {
 109                 if (gc_rq->lba_list[i] == ADDR_EMPTY)
 110                         continue;
 111
 112                 w_ctx.lba = gc_rq->lba_list[i];
 113
 114                 pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + valid_entries);
 115                 pblk_rb_write_entry_gc(&pblk->rwb, data, w_ctx, gc_rq->line,
 116                                                 gc_rq->paddr_list[i], pos);
 117
 118                 data += PBLK_EXPOSED_PAGE_SIZE;
 119                 valid_entries++;
 120         }
 121
 122         WARN_ONCE(gc_rq->secs_to_gc != valid_entries,
 123                                         "pblk: inconsistent GC write\n");
 124
 125         atomic64_add(valid_entries, &pblk->gc_wa);
 126
 127 #ifdef CONFIG_NVM_PBLK_DEBUG
 128         atomic_long_add(valid_entries, &pblk->inflight_writes);
 129         atomic_long_add(valid_entries, &pblk->recov_gc_writes);
 130 #endif
 131
 132         pblk_write_should_kick(pblk);
 133         return NVM_IO_OK;
 134 }