lfs_subr.c revision 1.2
1/* $NetBSD: lfs_subr.c,v 1.2 1994/06/29 06:47:00 cgd 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 8.2 (Berkeley) 9/21/93 36 */ 37 38#include <sys/param.h> 39#include <sys/namei.h> 40#include <sys/vnode.h> 41#include <sys/buf.h> 42#include <sys/mount.h> 43#include <sys/malloc.h> 44#include <sys/proc.h> 45 46#include <ufs/ufs/quota.h> 47#include <ufs/ufs/inode.h> 48#include <ufs/lfs/lfs.h> 49#include <ufs/lfs/lfs_extern.h> 50 51/* 52 * Return buffer with the contents of block "offset" from the beginning of 53 * directory "ip". If "res" is non-zero, fill it in with a pointer to the 54 * remaining space in the directory. 55 */ 56int 57lfs_blkatoff(ap) 58 struct vop_blkatoff_args /* { 59 struct vnode *a_vp; 60 off_t a_offset; 61 char **a_res; 62 struct buf **a_bpp; 63 } */ *ap; 64{ 65 register struct lfs *fs; 66 struct inode *ip; 67 struct buf *bp; 68 daddr_t lbn; 69 int bsize, error; 70 71 ip = VTOI(ap->a_vp); 72 fs = ip->i_lfs; 73 lbn = lblkno(fs, ap->a_offset); 74 bsize = blksize(fs); 75 76 *ap->a_bpp = NULL; 77 if (error = bread(ap->a_vp, lbn, bsize, NOCRED, &bp)) { 78 brelse(bp); 79 return (error); 80 } 81 if (ap->a_res) 82 *ap->a_res = (char *)bp->b_data + blkoff(fs, ap->a_offset); 83 *ap->a_bpp = bp; 84 return (0); 85} 86 87 88/* 89 * lfs_seglock -- 90 * Single thread the segment writer. 91 */ 92void 93lfs_seglock(fs, flags) 94 struct lfs *fs; 95 unsigned long flags; 96{ 97 struct segment *sp; 98 int s; 99 100 if (fs->lfs_seglock) 101 if (fs->lfs_lockpid == curproc->p_pid) { 102 ++fs->lfs_seglock; 103 fs->lfs_sp->seg_flags |= flags; 104 return; 105 } else while (fs->lfs_seglock) 106 (void)tsleep(&fs->lfs_seglock, PRIBIO + 1, 107 "lfs seglock", 0); 108 109 fs->lfs_seglock = 1; 110 fs->lfs_lockpid = curproc->p_pid; 111 112 sp = fs->lfs_sp = malloc(sizeof(struct segment), M_SEGMENT, M_WAITOK); 113 sp->bpp = malloc(((LFS_SUMMARY_SIZE - sizeof(SEGSUM)) / 114 sizeof(daddr_t) + 1) * sizeof(struct buf *), M_SEGMENT, M_WAITOK); 115 sp->seg_flags = flags; 116 sp->vp = NULL; 117 (void) lfs_initseg(fs); 118 119 /* 120 * Keep a cumulative count of the outstanding I/O operations. If the 121 * disk drive catches up with us it could go to zero before we finish, 122 * so we artificially increment it by one until we've scheduled all of 123 * the writes we intend to do. 124 */ 125 s = splbio(); 126 ++fs->lfs_iocount; 127 splx(s); 128} 129/* 130 * lfs_segunlock -- 131 * Single thread the segment writer. 132 */ 133void 134lfs_segunlock(fs) 135 struct lfs *fs; 136{ 137 struct segment *sp; 138 unsigned long sync, ckp; 139 int s; 140 141 if (fs->lfs_seglock == 1) { 142 143 sp = fs->lfs_sp; 144 sync = sp->seg_flags & SEGM_SYNC; 145 ckp = sp->seg_flags & SEGM_CKP; 146 if (sp->bpp != sp->cbpp) { 147 /* Free allocated segment summary */ 148 fs->lfs_offset -= LFS_SUMMARY_SIZE / DEV_BSIZE; 149 brelvp(*sp->bpp); 150 free((*sp->bpp)->b_data, M_SEGMENT); 151 free(*sp->bpp, M_SEGMENT); 152 } else 153 printf ("unlock to 0 with no summary"); 154 free(sp->bpp, M_SEGMENT); 155 free(sp, M_SEGMENT); 156 157 /* 158 * If the I/O count is non-zero, sleep until it reaches zero. 159 * At the moment, the user's process hangs around so we can 160 * sleep. 161 */ 162 s = splbio(); 163 --fs->lfs_iocount; 164 /* 165 * We let checkpoints happen asynchronously. That means 166 * that during recovery, we have to roll forward between 167 * the two segments described by the first and second 168 * superblocks to make sure that the checkpoint described 169 * by a superblock completed. 170 */ 171 if (sync && fs->lfs_iocount) 172 (void)tsleep(&fs->lfs_iocount, PRIBIO + 1, "lfs vflush", 0); 173 splx(s); 174 if (ckp) { 175 fs->lfs_nactive = 0; 176 lfs_writesuper(fs); 177 } 178 --fs->lfs_seglock; 179 fs->lfs_lockpid = 0; 180 wakeup(&fs->lfs_seglock); 181 } else if (fs->lfs_seglock == 0) { 182 panic ("Seglock not held"); 183 } else { 184 --fs->lfs_seglock; 185 } 186} 187