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/* $NetBSD: fssvar.h,v 1.1 2003/12/10 11:40:11 hannken Exp $ */
/*-
* Copyright (c) 2003 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Juergen Hannken-Illjes.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* 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.
*/
#ifndef _SYS_DEV_FSSVAR_H
#define _SYS_DEV_FSSVAR_H
struct fss_set {
char *fss_mount; /* Mount point of file system */
char *fss_bstore; /* Path of backing store */
blksize_t fss_csize; /* Preferred cluster size */
};
struct fss_get {
char fsg_mount[MNAMELEN]; /* Mount point of file system */
struct timeval fsg_time; /* Time this snapshot was taken */
blksize_t fsg_csize; /* Current cluster size */
blkcnt_t fsg_mount_size; /* # clusters on file system */
blkcnt_t fsg_bs_size; /* # clusters on backing store */
};
#define FSSIOCSET _IOW('F', 0, struct fss_set) /* Configure */
#define FSSIOCGET _IOR('F', 1, struct fss_get) /* Status */
#define FSSIOCCLR _IO('F', 2) /* Unconfigure */
#ifdef _KERNEL
#define FSS_CLUSTER_MAX (1<<24) /* Upper bound of clusters. The
sc_copied map uses
FSS_CLUSTER_MAX/NBBY bytes */
typedef enum {
FSS_CACHE_FREE = 0, /* Cache entry is free */
FSS_CACHE_BUSY = 1, /* Cache entry is read from device */
FSS_CACHE_VALID = 2 /* Cache entry contains valid data */
} fss_cache_type;
struct fss_cache {
fss_cache_type fc_type; /* Current state */
struct fss_softc *fc_softc; /* Backlink to our softc */
volatile int fc_xfercount; /* Number of outstanding transfers */
u_int32_t fc_cluster; /* Cluster number of this entry */
caddr_t fc_data; /* Data */
};
struct fss_softc {
int sc_unit; /* Logical unit number */
struct lock sc_lock; /* Get exclusive access to device */
volatile int sc_flags; /* Flags */
#define FSS_ACTIVE 0x01 /* Snapshot is active */
#define FSS_ERROR 0x02 /* I/o error occured */
#define FSS_BS_THREAD 0x04 /* Kernel thread is running */
struct mount *sc_mount; /* Mount point */
char sc_mntname[MNAMELEN]; /* Mount point */
struct timeval sc_time; /* Time this snapshot was taken */
dev_t sc_bdev; /* Underlying block device */
void (*sc_strategy)(struct buf *); /* And its strategy */
struct vnode *sc_bs_vp; /* Our backing store */
int sc_bs_bsize; /* Its bsize */
struct proc *sc_bs_proc; /* Our kernel thread */
u_int32_t sc_clsize; /* Size of cluster */
u_int32_t sc_clcount; /* # clusters in file system */
u_int8_t *sc_copied; /* Map of clusters already copied */
long sc_cllast; /* Bytes in last cluster */
int sc_cowcount; /* Number of cow in progress */
int sc_cache_size; /* Number of entries in sc_cache */
struct fss_cache *sc_cache; /* Cluster cache */
struct bufq_state sc_bufq; /* Transfer queue */
u_int32_t sc_clnext; /* Next free cluster on backing store */
int sc_indir_size; /* # clusters for indirect mapping */
u_int8_t *sc_indir_valid; /* Map of valid indirect clusters */
u_int32_t sc_indir_cur; /* Current indir cluster number */
int sc_indir_dirty; /* Current indir cluster modified */
u_int32_t *sc_indir_data; /* Current indir cluster data */
};
struct fss_softc fss_softc[NFSS];
void fss_copy_on_write(struct fss_softc *, struct buf *);
int fss_umount_hook(struct mount *, int);
/*
* Get this dev's softc if it is a valid device.
* Return a pointer to its softc.
*/
static inline int
fss_dev_to_softc(dev_t dev, struct fss_softc **scp)
{
int unit;
struct fss_softc *sc;
unit = minor(dev);
if (unit < 0 || unit >= NFSS)
return ENODEV;
sc = &fss_softc[unit];
*scp = sc;
return 0;
}
/*
* Check if this buf needs to be copied on write.
* Unroll the loop for small NFSS.
*/
static inline void
fss_cow_hook(struct buf *bp)
{
int i;
if (bp->b_flags & B_READ)
return;
if (NFSS <= 4) {
if (__predict_false(fss_softc[0].sc_bdev == bp->b_dev ||
(NFSS > 1 && fss_softc[1].sc_bdev == bp->b_dev) ||
(NFSS > 2 && fss_softc[2].sc_bdev == bp->b_dev) ||
(NFSS > 3 && fss_softc[3].sc_bdev == bp->b_dev)))
for (i = 0; i < NFSS; i++)
if (fss_softc[i].sc_bdev == bp->b_dev)
fss_copy_on_write(&fss_softc[i], bp);
} else {
for (i = 0; i < NFSS; i++)
if (__predict_false(fss_softc[i].sc_bdev == bp->b_dev))
fss_copy_on_write(&fss_softc[i], bp);
}
}
#endif /* _KERNEL */
#endif /* !_SYS_DEV_FSSVAR_H */
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