/*
* Copyright (C) 2015 IT University of Copenhagen (rrpc.c)
* 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.
*
* Implementation of a physical block-device target for Open-channel SSDs.
*
* pblk-init.c - pblk's initialization.
*/
#include "pblk.h"
static unsigned int write_buffer_size;
module_param(write_buffer_size, uint, 0644);
MODULE_PARM_DESC(write_buffer_size, "number of entries in a write buffer");
static struct kmem_cache *pblk_ws_cache, *pblk_rec_cache, *pblk_g_rq_cache,
*pblk_w_rq_cache;
static DECLARE_RWSEM(pblk_lock);
struct bio_set pblk_bio_set;
static int pblk_rw_io(struct request_queue *q, struct pblk *pblk,
struct bio *bio)
{
int ret;
/* Read requests must be <= 256kb due to NVMe's 64 bit completion bitmap
* constraint. Writes can be of arbitrary size.
*/
if (bio_data_dir(bio) == READ) {
blk_queue_split(q, &bio);
ret = pblk_submit_read(pblk, bio);
if (ret == NVM_IO_DONE && bio_flagged(bio, BIO_CLONED))
bio_put(bio);
return ret;
}
/* Prevent deadlock in the case of a modest LUN configuration and large
* user I/Os. Unless stalled, the rate limiter leaves at least 256KB
* available for user I/O.
*/
if (pblk_get_secs(bio) > pblk_rl_max_io(&pblk->rl))
blk_queue_split(q, &bio);
return pblk_write_to_cache(pblk, bio, PBLK_IOTYPE_USER);
}
static blk_qc_t pblk_make_rq(struct request_queue *q, struct bio *bio)
{
struct pblk *pblk = q->queuedata;
if (bio_op(bio) == REQ_OP_DISCARD) {
pblk_discard(pblk, bio);
if (!(bio->bi_opf & REQ_PREFLUSH)) {
bio_endio(bio);
return BLK_QC_T_NONE;
}