187 lines
5.3 KiB
C
187 lines
5.3 KiB
C
/*
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* Copyright (c) 1991, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)lfs_subr.c 8.2 (Berkeley) 9/21/93
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* $Id: lfs_subr.c,v 1.6 1995/01/09 16:05:23 davidg Exp $
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/namei.h>
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#include <sys/vnode.h>
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#include <sys/buf.h>
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#include <sys/mount.h>
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#include <sys/malloc.h>
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#include <sys/proc.h>
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#include <ufs/ufs/quota.h>
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#include <ufs/ufs/inode.h>
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#include <ufs/lfs/lfs.h>
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#include <ufs/lfs/lfs_extern.h>
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/*
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* Return buffer with the contents of block "offset" from the beginning of
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* directory "ip". If "res" is non-zero, fill it in with a pointer to the
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* remaining space in the directory.
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*/
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int
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lfs_blkatoff(ap)
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struct vop_blkatoff_args /* {
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struct vnode *a_vp;
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off_t a_offset;
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char **a_res;
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struct buf **a_bpp;
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} */ *ap;
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{
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register struct lfs *fs;
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struct inode *ip;
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struct buf *bp;
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daddr_t lbn;
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int bsize, error;
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ip = VTOI(ap->a_vp);
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fs = ip->i_lfs;
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lbn = lblkno(fs, ap->a_offset);
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bsize = blksize(fs);
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*ap->a_bpp = NULL;
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if (error = bread(ap->a_vp, lbn, bsize, NOCRED, &bp)) {
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brelse(bp);
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return (error);
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}
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if (ap->a_res)
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*ap->a_res = (char *)bp->b_data + blkoff(fs, ap->a_offset);
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*ap->a_bpp = bp;
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return (0);
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}
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/*
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* lfs_seglock --
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* Single thread the segment writer.
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*/
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void
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lfs_seglock(fs, flags)
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struct lfs *fs;
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unsigned long flags;
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{
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struct segment *sp;
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int s;
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if (fs->lfs_seglock)
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if (fs->lfs_lockpid == curproc->p_pid) {
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++fs->lfs_seglock;
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fs->lfs_sp->seg_flags |= flags;
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return;
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} else while (fs->lfs_seglock)
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(void)tsleep(&fs->lfs_seglock, PRIBIO + 1,
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"lfs seglock", 0);
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/* XXX RACE CONDITION????? */
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fs->lfs_seglock = 1;
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fs->lfs_lockpid = curproc->p_pid;
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sp = fs->lfs_sp = malloc(sizeof(struct segment), M_SEGMENT, M_WAITOK);
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sp->bpp = malloc(((LFS_SUMMARY_SIZE - sizeof(SEGSUM)) /
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sizeof(daddr_t) + 1) * sizeof(struct buf *), M_SEGMENT, M_WAITOK);
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sp->seg_flags = flags;
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sp->vp = NULL;
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(void) lfs_initseg(fs);
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/*
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* Keep a cumulative count of the outstanding I/O operations. If the
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* disk drive catches up with us it could go to zero before we finish,
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* so we artificially increment it by one until we've scheduled all of
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* the writes we intend to do.
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*/
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s = splbio();
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++fs->lfs_iocount;
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splx(s);
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}
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/*
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* lfs_segunlock --
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* Single thread the segment writer.
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*/
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void
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lfs_segunlock(fs)
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struct lfs *fs;
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{
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struct segment *sp;
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unsigned long sync, ckp;
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int s;
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if (fs->lfs_seglock == 1) {
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sp = fs->lfs_sp;
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sync = sp->seg_flags & SEGM_SYNC;
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ckp = sp->seg_flags & SEGM_CKP;
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if (sp->bpp != sp->cbpp) {
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/* Free allocated segment summary */
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fs->lfs_offset -= LFS_SUMMARY_SIZE / DEV_BSIZE;
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lfs_free_buffer((*sp->bpp)->b_data, roundup((*sp->bpp)->b_bufsize, DEV_BSIZE));
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relpbuf(*sp->bpp);
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} else
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printf ("unlock to 0 with no summary");
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free(sp->bpp, M_SEGMENT);
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free(sp, M_SEGMENT);
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/*
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* If the I/O count is non-zero, sleep until it reaches zero.
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* At the moment, the user's process hangs around so we can
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* sleep.
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*/
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s = splbio();
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--fs->lfs_iocount;
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/*
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* We let checkpoints happen asynchronously. That means
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* that during recovery, we have to roll forward between
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* the two segments described by the first and second
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* superblocks to make sure that the checkpoint described
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* by a superblock completed.
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*/
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if (sync && fs->lfs_iocount)
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(void)tsleep(&fs->lfs_iocount, PRIBIO + 1, "lfs vflush", 0);
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splx(s);
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if (ckp) {
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fs->lfs_nactive = 0;
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lfs_writesuper(fs);
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}
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--fs->lfs_seglock;
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fs->lfs_lockpid = 0;
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wakeup(&fs->lfs_seglock);
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} else if (fs->lfs_seglock == 0) {
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panic ("Seglock not held");
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} else {
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--fs->lfs_seglock;
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}
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}
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