linux/drivers/lightnvm/pblk-cache.c
Igor Konopko 3e03f6322a lightnvm: pblk: IO path reorganization
This patch is made in order to prepare read path for new approach to
partial read handling, which is simpler in compare with previous one.

The most important change is to move the handling of completed and
failed bio from the pblk_make_rq() to particular read and write
functions. This is needed, since after partial read path changes,
sometimes completed/failed bio will be different from original one, so
we cannot do this any longer in pblk_make_rq().

Other changes are small read path refactor in order to reduce the size
of the following patch with partial read changes.

Generally the goal of this patch is not to change the functionality,
but just to prepare the code for the following changes.

Signed-off-by: Igor Konopko <igor.j.konopko@intel.com>
Reviewed-by: Javier González <javier@javigon.com>
Signed-off-by: Matias Bjørling <mb@lightnvm.io>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-05-06 10:19:19 -06:00

140 lines
3.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2016 CNEX Labs
* Initial release: Javier Gonzalez <javier@cnexlabs.com>
* Matias Bjorling <matias@cnexlabs.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* pblk-cache.c - pblk's write cache
*/
#include "pblk.h"
void pblk_write_to_cache(struct pblk *pblk, struct bio *bio,
unsigned long flags)
{
struct request_queue *q = pblk->dev->q;
struct pblk_w_ctx w_ctx;
sector_t lba = pblk_get_lba(bio);
unsigned long start_time = jiffies;
unsigned int bpos, pos;
int nr_entries = pblk_get_secs(bio);
int i, ret;
generic_start_io_acct(q, REQ_OP_WRITE, bio_sectors(bio),
&pblk->disk->part0);
/* Update the write buffer head (mem) with the entries that we can
* write. The write in itself cannot fail, so there is no need to
* rollback from here on.
*/
retry:
ret = pblk_rb_may_write_user(&pblk->rwb, bio, nr_entries, &bpos);
switch (ret) {
case NVM_IO_REQUEUE:
io_schedule();
goto retry;
case NVM_IO_ERR:
pblk_pipeline_stop(pblk);
bio_io_error(bio);
goto out;
}
pblk_ppa_set_empty(&w_ctx.ppa);
w_ctx.flags = flags;
if (bio->bi_opf & REQ_PREFLUSH) {
w_ctx.flags |= PBLK_FLUSH_ENTRY;
pblk_write_kick(pblk);
}
if (unlikely(!bio_has_data(bio)))
goto out;
for (i = 0; i < nr_entries; i++) {
void *data = bio_data(bio);
w_ctx.lba = lba + i;
pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + i);
pblk_rb_write_entry_user(&pblk->rwb, data, w_ctx, pos);
bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
}
atomic64_add(nr_entries, &pblk->user_wa);
#ifdef CONFIG_NVM_PBLK_DEBUG
atomic_long_add(nr_entries, &pblk->inflight_writes);
atomic_long_add(nr_entries, &pblk->req_writes);
#endif
pblk_rl_inserted(&pblk->rl, nr_entries);
out:
generic_end_io_acct(q, REQ_OP_WRITE, &pblk->disk->part0, start_time);
pblk_write_should_kick(pblk);
if (ret == NVM_IO_DONE)
bio_endio(bio);
}
/*
* On GC the incoming lbas are not necessarily sequential. Also, some of the
* lbas might not be valid entries, which are marked as empty by the GC thread
*/
int pblk_write_gc_to_cache(struct pblk *pblk, struct pblk_gc_rq *gc_rq)
{
struct pblk_w_ctx w_ctx;
unsigned int bpos, pos;
void *data = gc_rq->data;
int i, valid_entries;
/* Update the write buffer head (mem) with the entries that we can
* write. The write in itself cannot fail, so there is no need to
* rollback from here on.
*/
retry:
if (!pblk_rb_may_write_gc(&pblk->rwb, gc_rq->secs_to_gc, &bpos)) {
io_schedule();
goto retry;
}
w_ctx.flags = PBLK_IOTYPE_GC;
pblk_ppa_set_empty(&w_ctx.ppa);
for (i = 0, valid_entries = 0; i < gc_rq->nr_secs; i++) {
if (gc_rq->lba_list[i] == ADDR_EMPTY)
continue;
w_ctx.lba = gc_rq->lba_list[i];
pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + valid_entries);
pblk_rb_write_entry_gc(&pblk->rwb, data, w_ctx, gc_rq->line,
gc_rq->paddr_list[i], pos);
data += PBLK_EXPOSED_PAGE_SIZE;
valid_entries++;
}
WARN_ONCE(gc_rq->secs_to_gc != valid_entries,
"pblk: inconsistent GC write\n");
atomic64_add(valid_entries, &pblk->gc_wa);
#ifdef CONFIG_NVM_PBLK_DEBUG
atomic_long_add(valid_entries, &pblk->inflight_writes);
atomic_long_add(valid_entries, &pblk->recov_gc_writes);
#endif
pblk_write_should_kick(pblk);
return NVM_IO_OK;
}