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/*
* Copyright (c) 1991, 1993
* The Regents of the University of California. 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
*
* @(#)lfs_subr.c 8.2 (Berkeley) 9/21/93
* $Id: lfs_subr.c,v 1.6 1995/01/09 16:05:23 davidg Exp $
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/buf.h>
#include <sys/mount.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <ufs/ufs/quota.h>
#include <ufs/ufs/inode.h>
#include <ufs/lfs/lfs.h>
#include <ufs/lfs/lfs_extern.h>
/*
* Return buffer with the contents of block "offset" from the beginning of
* directory "ip". If "res" is non-zero, fill it in with a pointer to the
* remaining space in the directory.
*/
int
lfs_blkatoff(ap)
struct vop_blkatoff_args /* {
struct vnode *a_vp;
off_t a_offset;
char **a_res;
struct buf **a_bpp;
} */ *ap;
{
register struct lfs *fs;
struct inode *ip;
struct buf *bp;
daddr_t lbn;
int bsize, error;
ip = VTOI(ap->a_vp);
fs = ip->i_lfs;
lbn = lblkno(fs, ap->a_offset);
bsize = blksize(fs);
*ap->a_bpp = NULL;
if (error = bread(ap->a_vp, lbn, bsize, NOCRED, &bp)) {
brelse(bp);
return (error);
}
if (ap->a_res)
*ap->a_res = (char *)bp->b_data + blkoff(fs, ap->a_offset);
*ap->a_bpp = bp;
return (0);
}
/*
* lfs_seglock --
* Single thread the segment writer.
*/
void
lfs_seglock(fs, flags)
struct lfs *fs;
unsigned long flags;
{
struct segment *sp;
int s;
if (fs->lfs_seglock)
if (fs->lfs_lockpid == curproc->p_pid) {
++fs->lfs_seglock;
fs->lfs_sp->seg_flags |= flags;
return;
} else while (fs->lfs_seglock)
(void)tsleep(&fs->lfs_seglock, PRIBIO + 1,
"lfs seglock", 0);
/* XXX RACE CONDITION????? */
fs->lfs_seglock = 1;
fs->lfs_lockpid = curproc->p_pid;
sp = fs->lfs_sp = malloc(sizeof(struct segment), M_SEGMENT, M_WAITOK);
sp->bpp = malloc(((LFS_SUMMARY_SIZE - sizeof(SEGSUM)) /
sizeof(daddr_t) + 1) * sizeof(struct buf *), M_SEGMENT, M_WAITOK);
sp->seg_flags = flags;
sp->vp = NULL;
(void) lfs_initseg(fs);
/*
* Keep a cumulative count of the outstanding I/O operations. If the
* disk drive catches up with us it could go to zero before we finish,
* so we artificially increment it by one until we've scheduled all of
* the writes we intend to do.
*/
s = splbio();
++fs->lfs_iocount;
splx(s);
}
/*
* lfs_segunlock --
* Single thread the segment writer.
*/
void
lfs_segunlock(fs)
struct lfs *fs;
{
struct segment *sp;
unsigned long sync, ckp;
int s;
if (fs->lfs_seglock == 1) {
sp = fs->lfs_sp;
sync = sp->seg_flags & SEGM_SYNC;
ckp = sp->seg_flags & SEGM_CKP;
if (sp->bpp != sp->cbpp) {
/* Free allocated segment summary */
fs->lfs_offset -= LFS_SUMMARY_SIZE / DEV_BSIZE;
lfs_free_buffer((*sp->bpp)->b_data, roundup((*sp->bpp)->b_bufsize, DEV_BSIZE));
relpbuf(*sp->bpp);
} else
printf ("unlock to 0 with no summary");
free(sp->bpp, M_SEGMENT);
free(sp, M_SEGMENT);
/*
* If the I/O count is non-zero, sleep until it reaches zero.
* At the moment, the user's process hangs around so we can
* sleep.
*/
s = splbio();
--fs->lfs_iocount;
/*
* We let checkpoints happen asynchronously. That means
* that during recovery, we have to roll forward between
* the two segments described by the first and second
* superblocks to make sure that the checkpoint described
* by a superblock completed.
*/
if (sync && fs->lfs_iocount)
(void)tsleep(&fs->lfs_iocount, PRIBIO + 1, "lfs vflush", 0);
splx(s);
if (ckp) {
fs->lfs_nactive = 0;
lfs_writesuper(fs);
}
--fs->lfs_seglock;
fs->lfs_lockpid = 0;
wakeup(&fs->lfs_seglock);
} else if (fs->lfs_seglock == 0) {
panic ("Seglock not held");
} else {
--fs->lfs_seglock;
}
}
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