drivers/lightnvm/pblk-cache.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2016 CNEX Labs
   4  * Initial release: Javier Gonzalez <javier@cnexlabs.com>
   5  *                  Matias Bjorling <matias@cnexlabs.com>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License version
   9  * 2 as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * pblk-cache.c - pblk's write cache
  17  */
  18
  19 #include "pblk.h"
  20
  21 int pblk_write_to_cache(struct pblk *pblk, struct bio *bio, unsigned long flags)
  22 {
  23         struct request_queue *q = pblk->dev->q;
  24         struct pblk_w_ctx w_ctx;
  25         sector_t lba = pblk_get_lba(bio);
  26         unsigned long start_time = jiffies;
  27         unsigned int bpos, pos;
  28         int nr_entries = pblk_get_secs(bio);
  29         int i, ret;
  30
  31         generic_start_io_acct(q, REQ_OP_WRITE, bio_sectors(bio),
  32                               &pblk->disk->part0);
  33
  34         /* Update the write buffer head (mem) with the entries that we can
  35          * write. The write in itself cannot fail, so there is no need to
  36          * rollback from here on.
  37          */
  38 retry:
  39         ret = pblk_rb_may_write_user(&pblk->rwb, bio, nr_entries, &bpos);
  40         switch (ret) {
  41         case NVM_IO_REQUEUE:
  42                 io_schedule();
  43                 goto retry;
  44         case NVM_IO_ERR:
  45                 pblk_pipeline_stop(pblk);
  46                 goto out;
  47         }
  48
  49         pblk_ppa_set_empty(&w_ctx.ppa);
  50         w_ctx.flags = flags;
  51         if (bio->bi_opf & REQ_PREFLUSH) {
  52                 w_ctx.flags |= PBLK_FLUSH_ENTRY;
  53                 pblk_write_kick(pblk);
  54         }
  55
  56         if (unlikely(!bio_has_data(bio)))
  57                 goto out;
  58
  59         for (i = 0; i < nr_entries; i++) {
  60                 void *data = bio_data(bio);
  61
  62                 w_ctx.lba = lba + i;
  63
  64                 pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + i);
  65                 pblk_rb_write_entry_user(&pblk->rwb, data, w_ctx, pos);
  66
  67                 bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
  68         }
  69
  70         atomic64_add(nr_entries, &pblk->user_wa);
  71
  72 #ifdef CONFIG_NVM_PBLK_DEBUG
  73         atomic_long_add(nr_entries, &pblk->inflight_writes);
  74         atomic_long_add(nr_entries, &pblk->req_writes);
  75 #endif
  76
  77         pblk_rl_inserted(&pblk->rl, nr_entries);
  78
  79 out:
  80         generic_end_io_acct(q, REQ_OP_WRITE, &pblk->disk->part0, start_time);
  81         pblk_write_should_kick(pblk);
  82         return ret;
  83 }
  84
  85 /*
  86  * On GC the incoming lbas are not necessarily sequential. Also, some of the
  87  * lbas might not be valid entries, which are marked as empty by the GC thread
  88  */
  89 int pblk_write_gc_to_cache(struct pblk *pblk, struct pblk_gc_rq *gc_rq)
  90 {
  91         struct pblk_w_ctx w_ctx;
  92         unsigned int bpos, pos;
  93         void *data = gc_rq->data;
  94         int i, valid_entries;
  95
  96         /* Update the write buffer head (mem) with the entries that we can
  97          * write. The write in itself cannot fail, so there is no need to
  98          * rollback from here on.
  99          */
 100 retry:
 101         if (!pblk_rb_may_write_gc(&pblk->rwb, gc_rq->secs_to_gc, &bpos)) {
 102                 io_schedule();
 103                 goto retry;
 104         }
 105
 106         w_ctx.flags = PBLK_IOTYPE_GC;
 107         pblk_ppa_set_empty(&w_ctx.ppa);
 108
 109         for (i = 0, valid_entries = 0; i < gc_rq->nr_secs; i++) {
 110                 if (gc_rq->lba_list[i] == ADDR_EMPTY)
 111                         continue;
 112
 113                 w_ctx.lba = gc_rq->lba_list[i];
 114
 115                 pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + valid_entries);
 116                 pblk_rb_write_entry_gc(&pblk->rwb, data, w_ctx, gc_rq->line,
 117                                                 gc_rq->paddr_list[i], pos);
 118
 119                 data += PBLK_EXPOSED_PAGE_SIZE;
 120                 valid_entries++;
 121         }
 122
 123         WARN_ONCE(gc_rq->secs_to_gc != valid_entries,
 124                                         "pblk: inconsistent GC write\n");
 125
 126         atomic64_add(valid_entries, &pblk->gc_wa);
 127
 128 #ifdef CONFIG_NVM_PBLK_DEBUG
 129         atomic_long_add(valid_entries, &pblk->inflight_writes);
 130         atomic_long_add(valid_entries, &pblk->recov_gc_writes);
 131 #endif
 132
 133         pblk_write_should_kick(pblk);
 134         return NVM_IO_OK;
 135 }