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 void pblk_write_to_cache(struct pblk *pblk, struct bio *bio,
  22                                 unsigned long flags)
  23 {
  24         struct request_queue *q = pblk->dev->q;
  25         struct pblk_w_ctx w_ctx;
  26         sector_t lba = pblk_get_lba(bio);
  27         unsigned long start_time = jiffies;
  28         unsigned int bpos, pos;
  29         int nr_entries = pblk_get_secs(bio);
  30         int i, ret;
  31
  32         generic_start_io_acct(q, REQ_OP_WRITE, bio_sectors(bio),
  33                               &pblk->disk->part0);
  34
  35         /* Update the write buffer head (mem) with the entries that we can
  36          * write. The write in itself cannot fail, so there is no need to
  37          * rollback from here on.
  38          */
  39 retry:
  40         ret = pblk_rb_may_write_user(&pblk->rwb, bio, nr_entries, &bpos);
  41         switch (ret) {
  42         case NVM_IO_REQUEUE:
  43                 io_schedule();
  44                 goto retry;
  45         case NVM_IO_ERR:
  46                 pblk_pipeline_stop(pblk);
  47                 bio_io_error(bio);
  48                 goto out;
  49         }
  50
  51         pblk_ppa_set_empty(&w_ctx.ppa);
  52         w_ctx.flags = flags;
  53         if (bio->bi_opf & REQ_PREFLUSH) {
  54                 w_ctx.flags |= PBLK_FLUSH_ENTRY;
  55                 pblk_write_kick(pblk);
  56         }
  57
  58         if (unlikely(!bio_has_data(bio)))
  59                 goto out;
  60
  61         for (i = 0; i < nr_entries; i++) {
  62                 void *data = bio_data(bio);
  63
  64                 w_ctx.lba = lba + i;
  65
  66                 pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + i);
  67                 pblk_rb_write_entry_user(&pblk->rwb, data, w_ctx, pos);
  68
  69                 bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
  70         }
  71
  72         atomic64_add(nr_entries, &pblk->user_wa);
  73
  74 #ifdef CONFIG_NVM_PBLK_DEBUG
  75         atomic_long_add(nr_entries, &pblk->inflight_writes);
  76         atomic_long_add(nr_entries, &pblk->req_writes);
  77 #endif
  78
  79         pblk_rl_inserted(&pblk->rl, nr_entries);
  80
  81 out:
  82         generic_end_io_acct(q, REQ_OP_WRITE, &pblk->disk->part0, start_time);
  83         pblk_write_should_kick(pblk);
  84
  85         if (ret == NVM_IO_DONE)
  86                 bio_endio(bio);
  87 }
  88
  89 /*
  90  * On GC the incoming lbas are not necessarily sequential. Also, some of the
  91  * lbas might not be valid entries, which are marked as empty by the GC thread
  92  */
  93 int pblk_write_gc_to_cache(struct pblk *pblk, struct pblk_gc_rq *gc_rq)
  94 {
  95         struct pblk_w_ctx w_ctx;
  96         unsigned int bpos, pos;
  97         void *data = gc_rq->data;
  98         int i, valid_entries;
  99
 100         /* Update the write buffer head (mem) with the entries that we can
 101          * write. The write in itself cannot fail, so there is no need to
 102          * rollback from here on.
 103          */
 104 retry:
 105         if (!pblk_rb_may_write_gc(&pblk->rwb, gc_rq->secs_to_gc, &bpos)) {
 106                 io_schedule();
 107                 goto retry;
 108         }
 109
 110         w_ctx.flags = PBLK_IOTYPE_GC;
 111         pblk_ppa_set_empty(&w_ctx.ppa);
 112
 113         for (i = 0, valid_entries = 0; i < gc_rq->nr_secs; i++) {
 114                 if (gc_rq->lba_list[i] == ADDR_EMPTY)
 115                         continue;
 116
 117                 w_ctx.lba = gc_rq->lba_list[i];
 118
 119                 pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + valid_entries);
 120                 pblk_rb_write_entry_gc(&pblk->rwb, data, w_ctx, gc_rq->line,
 121                                                 gc_rq->paddr_list[i], pos);
 122
 123                 data += PBLK_EXPOSED_PAGE_SIZE;
 124                 valid_entries++;
 125         }
 126
 127         WARN_ONCE(gc_rq->secs_to_gc != valid_entries,
 128                                         "pblk: inconsistent GC write\n");
 129
 130         atomic64_add(valid_entries, &pblk->gc_wa);
 131
 132 #ifdef CONFIG_NVM_PBLK_DEBUG
 133         atomic_long_add(valid_entries, &pblk->inflight_writes);
 134         atomic_long_add(valid_entries, &pblk->recov_gc_writes);
 135 #endif
 136
 137         pblk_write_should_kick(pblk);
 138         return NVM_IO_OK;
 139 }