lfs_subr.c revision 1.1
1 /* 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * from: @(#)lfs_subr.c 8.2 (Berkeley) 9/21/93 34 * $Id: lfs_subr.c,v 1.1 1994/06/08 11:42:43 mycroft Exp $ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/namei.h> 39 #include <sys/vnode.h> 40 #include <sys/buf.h> 41 #include <sys/mount.h> 42 #include <sys/malloc.h> 43 #include <sys/proc.h> 44 45 #include <ufs/ufs/quota.h> 46 #include <ufs/ufs/inode.h> 47 #include <ufs/lfs/lfs.h> 48 #include <ufs/lfs/lfs_extern.h> 49 50 /* 51 * Return buffer with the contents of block "offset" from the beginning of 52 * directory "ip". If "res" is non-zero, fill it in with a pointer to the 53 * remaining space in the directory. 54 */ 55 int 56 lfs_blkatoff(ap) 57 struct vop_blkatoff_args /* { 58 struct vnode *a_vp; 59 off_t a_offset; 60 char **a_res; 61 struct buf **a_bpp; 62 } */ *ap; 63 { 64 register struct lfs *fs; 65 struct inode *ip; 66 struct buf *bp; 67 daddr_t lbn; 68 int bsize, error; 69 70 ip = VTOI(ap->a_vp); 71 fs = ip->i_lfs; 72 lbn = lblkno(fs, ap->a_offset); 73 bsize = blksize(fs); 74 75 *ap->a_bpp = NULL; 76 if (error = bread(ap->a_vp, lbn, bsize, NOCRED, &bp)) { 77 brelse(bp); 78 return (error); 79 } 80 if (ap->a_res) 81 *ap->a_res = (char *)bp->b_data + blkoff(fs, ap->a_offset); 82 *ap->a_bpp = bp; 83 return (0); 84 } 85 86 87 /* 88 * lfs_seglock -- 89 * Single thread the segment writer. 90 */ 91 void 92 lfs_seglock(fs, flags) 93 struct lfs *fs; 94 unsigned long flags; 95 { 96 struct segment *sp; 97 int s; 98 99 if (fs->lfs_seglock) 100 if (fs->lfs_lockpid == curproc->p_pid) { 101 ++fs->lfs_seglock; 102 fs->lfs_sp->seg_flags |= flags; 103 return; 104 } else while (fs->lfs_seglock) 105 (void)tsleep(&fs->lfs_seglock, PRIBIO + 1, 106 "lfs seglock", 0); 107 108 fs->lfs_seglock = 1; 109 fs->lfs_lockpid = curproc->p_pid; 110 111 sp = fs->lfs_sp = malloc(sizeof(struct segment), M_SEGMENT, M_WAITOK); 112 sp->bpp = malloc(((LFS_SUMMARY_SIZE - sizeof(SEGSUM)) / 113 sizeof(daddr_t) + 1) * sizeof(struct buf *), M_SEGMENT, M_WAITOK); 114 sp->seg_flags = flags; 115 sp->vp = NULL; 116 (void) lfs_initseg(fs); 117 118 /* 119 * Keep a cumulative count of the outstanding I/O operations. If the 120 * disk drive catches up with us it could go to zero before we finish, 121 * so we artificially increment it by one until we've scheduled all of 122 * the writes we intend to do. 123 */ 124 s = splbio(); 125 ++fs->lfs_iocount; 126 splx(s); 127 } 128 /* 129 * lfs_segunlock -- 130 * Single thread the segment writer. 131 */ 132 void 133 lfs_segunlock(fs) 134 struct lfs *fs; 135 { 136 struct segment *sp; 137 unsigned long sync, ckp; 138 int s; 139 140 if (fs->lfs_seglock == 1) { 141 142 sp = fs->lfs_sp; 143 sync = sp->seg_flags & SEGM_SYNC; 144 ckp = sp->seg_flags & SEGM_CKP; 145 if (sp->bpp != sp->cbpp) { 146 /* Free allocated segment summary */ 147 fs->lfs_offset -= LFS_SUMMARY_SIZE / DEV_BSIZE; 148 brelvp(*sp->bpp); 149 free((*sp->bpp)->b_data, M_SEGMENT); 150 free(*sp->bpp, M_SEGMENT); 151 } else 152 printf ("unlock to 0 with no summary"); 153 free(sp->bpp, M_SEGMENT); 154 free(sp, M_SEGMENT); 155 156 /* 157 * If the I/O count is non-zero, sleep until it reaches zero. 158 * At the moment, the user's process hangs around so we can 159 * sleep. 160 */ 161 s = splbio(); 162 --fs->lfs_iocount; 163 /* 164 * We let checkpoints happen asynchronously. That means 165 * that during recovery, we have to roll forward between 166 * the two segments described by the first and second 167 * superblocks to make sure that the checkpoint described 168 * by a superblock completed. 169 */ 170 if (sync && fs->lfs_iocount) 171 (void)tsleep(&fs->lfs_iocount, PRIBIO + 1, "lfs vflush", 0); 172 splx(s); 173 if (ckp) { 174 fs->lfs_nactive = 0; 175 lfs_writesuper(fs); 176 } 177 --fs->lfs_seglock; 178 fs->lfs_lockpid = 0; 179 wakeup(&fs->lfs_seglock); 180 } else if (fs->lfs_seglock == 0) { 181 panic ("Seglock not held"); 182 } else { 183 --fs->lfs_seglock; 184 } 185 } 186
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