NetBSD/sys/dev/raidframe/rf_paritymap.h

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/* $NetBSD: rf_paritymap.h,v 1.1 2009/11/17 18:54:26 jld Exp $ */
/*-
* Copyright (c) 2009 Jed Davis.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/mutex.h>
#include <sys/param.h>
#include <sys/rwlock.h>
#include <sys/types.h>
#include <dev/raidframe/raidframevar.h>
/* RF_PARITYMAP_N* in raidframevar.h */
#define RF_PMLABEL_VALID 1
#define RF_PMLABEL_WASUSED 2
#define RF_PMLABEL_DISABLE 4
/*
* On-disk format: a single bit for each region; if the bit is clear,
* then the parity is clean.
*/
struct rf_paritymap_ondisk
{
/* XXX Do these really need to be volatile? */
volatile char bits[RF_PARITYMAP_NBYTE];
};
/* In-core per-region state: a byte for each, encoded as follows. */
struct rf_paritymap_current
{
volatile int8_t state[RF_PARITYMAP_NREG];
/*
* Values:
* if x == 0, the region may be written out as clean
* if x > 0, then x outstanding IOs to that region
* if x < 0, then there was recently IO; periodically increment x
*/
};
/* The entire state. */
struct rf_paritymap
{
struct rf_paritymap_ondisk *disk_boot, *disk_now;
struct rf_paritymap_current *current;
/*
* This lock will be held while component disks' caches are
* flushed, which could take many milliseconds, so it should
* not be taken where that kind of delay is unacceptable.
* Contention on this lock is not, however, expected to be a
* performance bottleneck.
*/
kmutex_t lock;
/*
* The flags field, below, has its own lock so that
* inter-thread communication can occur without taking the
* overall lock. Ordering is lock -> lk_flags.
*/
kmutex_t lk_flags;
RF_Raid_t *raid;
daddr_t region_size;
callout_t ticker;
struct rf_pmparams params;
volatile int flags;
struct rf_pmctrs ctrs;
};
void rf_paritymap_status(struct rf_paritymap *, struct rf_pmstat *);
int rf_paritymap_test(struct rf_paritymap *, daddr_t);
void rf_paritymap_begin_region(struct rf_paritymap *, unsigned);
void rf_paritymap_begin(struct rf_paritymap *, daddr_t, daddr_t);
void rf_paritymap_end_region(struct rf_paritymap *, unsigned);
void rf_paritymap_end(struct rf_paritymap *, daddr_t, daddr_t);
void rf_paritymap_checkwork(struct rf_paritymap *);
void rf_paritymap_invalidate(struct rf_paritymap *);
void rf_paritymap_forceclean(struct rf_paritymap *);
void rf_paritymap_write(struct rf_paritymap *);
int rf_paritymap_init(struct rf_paritymap *, RF_Raid_t *,
const struct rf_pmparams *);
void rf_paritymap_destroy(struct rf_paritymap *, int);
int rf_paritymap_rewrite(struct rf_paritymap *);
int rf_paritymap_merge(struct rf_paritymap_ondisk *,
struct rf_paritymap_ondisk *);
void rf_paritymap_attach(RF_Raid_t *, int);
void rf_paritymap_detach(RF_Raid_t *); /* Not while the RAID is live! */
int rf_paritymap_get_disable(RF_Raid_t *);
void rf_paritymap_set_disable(RF_Raid_t *, int);
int rf_paritymap_set_params(struct rf_paritymap *,
const struct rf_pmparams *, int);
void rf_paritymap_init_label(struct rf_paritymap *,
RF_ComponentLabel_t *);