/*
drbd_req.c
This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
Copyright (C) 2001-2008, LINBIT Information Technologies GmbH.
Copyright (C) 1999-2008, Philipp Reisner <philipp.reisner@linbit.com>.
Copyright (C) 2002-2008, Lars Ellenberg <lars.ellenberg@linbit.com>.
drbd is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
drbd 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.
You should have received a copy of the GNU General Public License
along with drbd; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/drbd.h>
#include "drbd_int.h"
#include "drbd_req.h"
static bool drbd_may_do_local_read(struct drbd_conf *mdev, sector_t sector, int size);
/* Update disk stats at start of I/O request */
static void _drbd_start_io_acct(struct drbd_conf *mdev, struct drbd_request *req, struct bio *bio)
{
const int rw = bio_data_dir(bio);
int cpu;
cpu = part_stat_lock();
part_round_stats(cpu, &mdev->vdisk->part0);
part_stat_inc(cpu, &mdev->vdisk->part0, ios[rw]);
part_stat_add(cpu, &mdev->vdisk->part0, sectors[rw], bio_sectors(bio));
(void) cpu; /* The macro invocations above want the cpu argument, I do not like
the compiler warning about cpu only assigned but never used... */
part_inc_in_flight(&mdev->vdisk->part0, rw);
part_stat_unlock();
}
/* Update disk stats when completing request upwards */
static void _drbd_end_io_acct(struct drbd_conf *mdev, struct drbd_request *req)
{
int rw = bio_data_dir(req->master_bio);
unsigned long duration = jiffies - req->start_time;
int cpu;
cpu = part_stat_lock();
part_stat_add(cpu, &mdev->vdisk->part0, ticks[rw], duration);
part_round_stats(cpu, &mdev->vdisk->part0);
part_dec_in_flight(&mdev->vdisk->part0, rw);
part_stat_unlock();
}
static struct drbd_request *drbd_req_new(struct drbd_conf *mdev,
struct bio *bio_src)
{
struct drbd_request *req;
req = mempool_alloc(drbd_request_mempool, GFP_NOIO);
if (!req)
return NULL;
drbd_req_make_private_bio(req, bio_src);
req->rq_state = bio_data_dir(bio_src) == WRITE ? RQ_WRITE : 0;
req->w.mdev = mdev;
req->master_bio = bio_src;
req->epoch = 0;
drbd_clear_interval(&req->i);
req->i.sector = 