lfs_subr.c revision 1.3
1 /* $NetBSD: lfs_subr.c,v 1.3 1996/02/09 22:28:55 christos 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/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 */ 57 int 58 lfs_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 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); 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 */ 94 void 95 lfs_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(daddr_t) + 1) * sizeof(struct buf *), M_SEGMENT, M_WAITOK); 117 sp->seg_flags = flags; 118 sp->vp = NULL; 119 (void) lfs_initseg(fs); 120 121 /* 122 * Keep a cumulative count of the outstanding I/O operations. If the 123 * disk drive catches up with us it could go to zero before we finish, 124 * so we artificially increment it by one until we've scheduled all of 125 * the writes we intend to do. 126 */ 127 s = splbio(); 128 ++fs->lfs_iocount; 129 splx(s); 130 } 131 /* 132 * lfs_segunlock -- 133 * Single thread the segment writer. 134 */ 135 void 136 lfs_segunlock(fs) 137 struct lfs *fs; 138 { 139 struct segment *sp; 140 unsigned long sync, ckp; 141 int s; 142 143 if (fs->lfs_seglock == 1) { 144 145 sp = fs->lfs_sp; 146 sync = sp->seg_flags & SEGM_SYNC; 147 ckp = sp->seg_flags & SEGM_CKP; 148 if (sp->bpp != sp->cbpp) { 149 /* Free allocated segment summary */ 150 fs->lfs_offset -= LFS_SUMMARY_SIZE / DEV_BSIZE; 151 brelvp(*sp->bpp); 152 free((*sp->bpp)->b_data, M_SEGMENT); 153 free(*sp->bpp, M_SEGMENT); 154 } else 155 printf ("unlock to 0 with no summary"); 156 free(sp->bpp, M_SEGMENT); 157 free(sp, M_SEGMENT); 158 159 /* 160 * If the I/O count is non-zero, sleep until it reaches zero. 161 * At the moment, the user's process hangs around so we can 162 * sleep. 163 */ 164 s = splbio(); 165 --fs->lfs_iocount; 166 /* 167 * We let checkpoints happen asynchronously. That means 168 * that during recovery, we have to roll forward between 169 * the two segments described by the first and second 170 * superblocks to make sure that the checkpoint described 171 * by a superblock completed. 172 */ 173 if (sync && fs->lfs_iocount) 174 (void)tsleep(&fs->lfs_iocount, PRIBIO + 1, "lfs vflush", 0); 175 splx(s); 176 if (ckp) { 177 fs->lfs_nactive = 0; 178 lfs_writesuper(fs); 179 } 180 --fs->lfs_seglock; 181 fs->lfs_lockpid = 0; 182 wakeup(&fs->lfs_seglock); 183 } else if (fs->lfs_seglock == 0) { 184 panic ("Seglock not held"); 185 } else { 186 --fs->lfs_seglock; 187 } 188 } 189
Indexes created Wed Sep 24 15:09:51 GMT 2025