lfs_subr.c revision 1.6
1/* $NetBSD: lfs_subr.c,v 1.6 1998/03/01 02:23:25 fvdl Exp $ */ 2 3/* 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)lfs_subr.c 8.4 (Berkeley) 5/8/95 36 */ 37 38#include <sys/param.h> 39#include <sys/systm.h> 40#include <sys/namei.h> 41#include <sys/vnode.h> 42#include <sys/buf.h> 43#include <sys/mount.h> 44#include <sys/malloc.h> 45#include <sys/proc.h> 46 47#include <ufs/ufs/quota.h> 48#include <ufs/ufs/inode.h> 49#include <ufs/lfs/lfs.h> 50#include <ufs/lfs/lfs_extern.h> 51 52/* 53 * Return buffer with the contents of block "offset" from the beginning of 54 * directory "ip". If "res" is non-zero, fill it in with a pointer to the 55 * remaining space in the directory. 56 */ 57int 58lfs_blkatoff(v) 59 void *v; 60{ 61 struct vop_blkatoff_args /* { 62 struct vnode *a_vp; 63 off_t a_offset; 64 char **a_res; 65 struct buf **a_bpp; 66 } */ *ap = v; 67 register struct lfs *fs; 68 struct inode *ip; 69 struct buf *bp; 70 ufs_daddr_t lbn; 71 int bsize, error; 72 73 ip = VTOI(ap->a_vp); 74 fs = ip->i_lfs; 75 lbn = lblkno(fs, ap->a_offset); 76 bsize = blksize(fs, ip, lbn); 77 78 *ap->a_bpp = NULL; 79 if ((error = bread(ap->a_vp, lbn, bsize, NOCRED, &bp)) != 0) { 80 brelse(bp); 81 return (error); 82 } 83 if (ap->a_res) 84 *ap->a_res = (char *)bp->b_data + blkoff(fs, ap->a_offset); 85 *ap->a_bpp = bp; 86 return (0); 87} 88 89 90/* 91 * lfs_seglock -- 92 * Single thread the segment writer. 93 */ 94void 95lfs_seglock(fs, flags) 96 struct lfs *fs; 97 unsigned long flags; 98{ 99 struct segment *sp; 100 int s; 101 102 if (fs->lfs_seglock) 103 if (fs->lfs_lockpid == curproc->p_pid) { 104 ++fs->lfs_seglock; 105 fs->lfs_sp->seg_flags |= flags; 106 return; 107 } else while (fs->lfs_seglock) 108 (void)tsleep(&fs->lfs_seglock, PRIBIO + 1, 109 "lfs seglock", 0); 110 111 fs->lfs_seglock = 1; 112 fs->lfs_lockpid = curproc->p_pid; 113 114 sp = fs->lfs_sp = malloc(sizeof(struct segment), M_SEGMENT, M_WAITOK); 115 sp->bpp = malloc(((LFS_SUMMARY_SIZE - sizeof(SEGSUM)) / 116 sizeof(ufs_daddr_t) + 1) * sizeof(struct buf *), M_SEGMENT, 117 M_WAITOK); 118 sp->seg_flags = flags; 119 sp->vp = NULL; 120 (void) lfs_initseg(fs); 121 122 /* 123 * Keep a cumulative count of the outstanding I/O operations. If the 124 * disk drive catches up with us it could go to zero before we finish, 125 * so we artificially increment it by one until we've scheduled all of 126 * the writes we intend to do. 127 */ 128 s = splbio(); 129 ++fs->lfs_iocount; 130 splx(s); 131} 132/* 133 * lfs_segunlock -- 134 * Single thread the segment writer. 135 */ 136void 137lfs_segunlock(fs) 138 struct lfs *fs; 139{ 140 struct segment *sp; 141 unsigned long sync, ckp; 142 int s; 143 144 if (fs->lfs_seglock == 1) { 145 146 sp = fs->lfs_sp; 147 sync = sp->seg_flags & SEGM_SYNC; 148 ckp = sp->seg_flags & SEGM_CKP; 149 if (sp->bpp != sp->cbpp) { 150 /* Free allocated segment summary */ 151 fs->lfs_offset -= LFS_SUMMARY_SIZE / DEV_BSIZE; 152 brelvp(*sp->bpp); 153 free((*sp->bpp)->b_data, M_SEGMENT); 154 free(*sp->bpp, M_SEGMENT); 155 } else 156 printf ("unlock to 0 with no summary"); 157 free(sp->bpp, M_SEGMENT); 158 free(sp, M_SEGMENT); 159 160 /* 161 * If the I/O count is non-zero, sleep until it reaches zero. 162 * At the moment, the user's process hangs around so we can 163 * sleep. 164 */ 165 s = splbio(); 166 --fs->lfs_iocount; 167 /* 168 * We let checkpoints happen asynchronously. That means 169 * that during recovery, we have to roll forward between 170 * the two segments described by the first and second 171 * superblocks to make sure that the checkpoint described 172 * by a superblock completed. 173 */ 174 if (sync && fs->lfs_iocount) 175 (void)tsleep(&fs->lfs_iocount, PRIBIO + 1, "lfs vflush", 0); 176 splx(s); 177 if (ckp) { 178 fs->lfs_nactive = 0; 179 lfs_writesuper(fs); 180 } 181 --fs->lfs_seglock; 182 fs->lfs_lockpid = 0; 183 wakeup(&fs->lfs_seglock); 184 } else if (fs->lfs_seglock == 0) { 185 panic ("Seglock not held"); 186 } else { 187 --fs->lfs_seglock; 188 } 189} 190