Annotation of sys/ufs/ffs/ffs_subr.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: ffs_subr.c,v 1.20 2007/05/26 20:26:51 pedro Exp $ */
! 2: /* $NetBSD: ffs_subr.c,v 1.6 1996/03/17 02:16:23 christos Exp $ */
! 3:
! 4: /*
! 5: * Copyright (c) 1982, 1986, 1989, 1993
! 6: * The Regents of the University of California. All rights reserved.
! 7: *
! 8: * Redistribution and use in source and binary forms, with or without
! 9: * modification, are permitted provided that the following conditions
! 10: * are met:
! 11: * 1. Redistributions of source code must retain the above copyright
! 12: * notice, this list of conditions and the following disclaimer.
! 13: * 2. Redistributions in binary form must reproduce the above copyright
! 14: * notice, this list of conditions and the following disclaimer in the
! 15: * documentation and/or other materials provided with the distribution.
! 16: * 3. Neither the name of the University nor the names of its contributors
! 17: * may be used to endorse or promote products derived from this software
! 18: * without specific prior written permission.
! 19: *
! 20: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
! 21: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 22: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 23: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
! 24: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 25: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 26: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 27: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 28: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 29: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 30: * SUCH DAMAGE.
! 31: *
! 32: * @(#)ffs_subr.c 8.2 (Berkeley) 9/21/93
! 33: */
! 34:
! 35: #include <sys/param.h>
! 36: #include <ufs/ffs/fs.h>
! 37:
! 38: #ifdef _KERNEL
! 39: #include <sys/systm.h>
! 40: #include <sys/vnode.h>
! 41: #include <sys/mount.h>
! 42: #include <sys/buf.h>
! 43:
! 44: #include <ufs/ufs/quota.h>
! 45: #include <ufs/ufs/inode.h>
! 46: #include <ufs/ufs/ufsmount.h>
! 47: #include <ufs/ufs/ufs_extern.h>
! 48:
! 49: #include <ufs/ffs/ffs_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: */
! 56: int
! 57: ffs_bufatoff(struct inode *ip, off_t offset, char **res, struct buf **bpp)
! 58: {
! 59: struct fs *fs;
! 60: struct vnode *vp;
! 61: struct buf *bp;
! 62: daddr_t lbn;
! 63: int bsize, error;
! 64:
! 65: vp = ITOV(ip);
! 66: fs = ip->i_fs;
! 67: lbn = lblkno(fs, offset);
! 68: bsize = blksize(fs, ip, lbn);
! 69:
! 70: *bpp = NULL;
! 71: if ((error = bread(vp, lbn, fs->fs_bsize, NOCRED, &bp)) != 0) {
! 72: brelse(bp);
! 73: return (error);
! 74: }
! 75: bp->b_bcount = bsize;
! 76: if (res)
! 77: *res = (char *)bp->b_data + blkoff(fs, offset);
! 78: *bpp = bp;
! 79: return (0);
! 80: }
! 81: #else
! 82: /* Prototypes for userland */
! 83: void ffs_fragacct(struct fs *, int, int32_t[], int);
! 84: int ffs_isfreeblock(struct fs *, unsigned char *, daddr_t);
! 85: int ffs_isblock(struct fs *, unsigned char *, daddr_t);
! 86: void ffs_clrblock(struct fs *, u_char *, daddr_t);
! 87: void ffs_setblock(struct fs *, unsigned char *, daddr_t);
! 88: __dead void panic(const char *, ...);
! 89: #endif
! 90:
! 91: /*
! 92: * Update the frsum fields to reflect addition or deletion
! 93: * of some frags.
! 94: */
! 95: void
! 96: ffs_fragacct(struct fs *fs, int fragmap, int32_t fraglist[], int cnt)
! 97: {
! 98: int inblk;
! 99: int field, subfield;
! 100: int siz, pos;
! 101:
! 102: inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1;
! 103: fragmap <<= 1;
! 104: for (siz = 1; siz < fs->fs_frag; siz++) {
! 105: if ((inblk & (1 << (siz + (fs->fs_frag % NBBY)))) == 0)
! 106: continue;
! 107: field = around[siz];
! 108: subfield = inside[siz];
! 109: for (pos = siz; pos <= fs->fs_frag; pos++) {
! 110: if ((fragmap & field) == subfield) {
! 111: fraglist[siz] += cnt;
! 112: pos += siz;
! 113: field <<= siz;
! 114: subfield <<= siz;
! 115: }
! 116: field <<= 1;
! 117: subfield <<= 1;
! 118: }
! 119: }
! 120: }
! 121:
! 122: #if defined(_KERNEL) && defined(DIAGNOSTIC)
! 123: void
! 124: ffs_checkoverlap(struct buf *bp, struct inode *ip)
! 125: {
! 126: daddr_t start, last;
! 127: struct vnode *vp;
! 128: struct buf *ep;
! 129:
! 130: start = bp->b_blkno;
! 131: last = start + btodb(bp->b_bcount) - 1;
! 132: LIST_FOREACH(ep, &bufhead, b_list) {
! 133: if (ep == bp || (ep->b_flags & B_INVAL) ||
! 134: ep->b_vp == NULLVP)
! 135: continue;
! 136: if (VOP_BMAP(ep->b_vp, (daddr_t)0, &vp, (daddr_t)0, NULL))
! 137: continue;
! 138: if (vp != ip->i_devvp)
! 139: continue;
! 140: /* look for overlap */
! 141: if (ep->b_bcount == 0 || ep->b_blkno > last ||
! 142: ep->b_blkno + btodb(ep->b_bcount) <= start)
! 143: continue;
! 144: vprint("Disk overlap", vp);
! 145: (void)printf("\tstart %d, end %d overlap start %d, end %ld\n",
! 146: start, last, ep->b_blkno,
! 147: ep->b_blkno + btodb(ep->b_bcount) - 1);
! 148: panic("Disk buffer overlap");
! 149: }
! 150: }
! 151: #endif /* DIAGNOSTIC */
! 152:
! 153: /*
! 154: * block operations
! 155: *
! 156: * check if a block is available
! 157: */
! 158: int
! 159: ffs_isblock(struct fs *fs, unsigned char *cp, daddr_t h)
! 160: {
! 161: unsigned char mask;
! 162:
! 163: switch (fs->fs_frag) {
! 164: default:
! 165: case 8:
! 166: return (cp[h] == 0xff);
! 167: case 4:
! 168: mask = 0x0f << ((h & 0x1) << 2);
! 169: return ((cp[h >> 1] & mask) == mask);
! 170: case 2:
! 171: mask = 0x03 << ((h & 0x3) << 1);
! 172: return ((cp[h >> 2] & mask) == mask);
! 173: case 1:
! 174: mask = 0x01 << (h & 0x7);
! 175: return ((cp[h >> 3] & mask) == mask);
! 176: }
! 177: }
! 178:
! 179: /*
! 180: * take a block out of the map
! 181: */
! 182: void
! 183: ffs_clrblock(struct fs *fs, u_char *cp, daddr_t h)
! 184: {
! 185:
! 186: switch (fs->fs_frag) {
! 187: default:
! 188: case 8:
! 189: cp[h] = 0;
! 190: return;
! 191: case 4:
! 192: cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
! 193: return;
! 194: case 2:
! 195: cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
! 196: return;
! 197: case 1:
! 198: cp[h >> 3] &= ~(0x01 << (h & 0x7));
! 199: return;
! 200: }
! 201: }
! 202:
! 203: /*
! 204: * put a block into the map
! 205: */
! 206: void
! 207: ffs_setblock(struct fs *fs, unsigned char *cp, daddr_t h)
! 208: {
! 209:
! 210: switch (fs->fs_frag) {
! 211: default:
! 212: case 8:
! 213: cp[h] = 0xff;
! 214: return;
! 215: case 4:
! 216: cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
! 217: return;
! 218: case 2:
! 219: cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
! 220: return;
! 221: case 1:
! 222: cp[h >> 3] |= (0x01 << (h & 0x7));
! 223: return;
! 224: }
! 225: }
! 226:
! 227: /*
! 228: * check if a block is free
! 229: */
! 230: int
! 231: ffs_isfreeblock(struct fs *fs, unsigned char *cp, daddr_t h)
! 232: {
! 233:
! 234: switch (fs->fs_frag) {
! 235: default:
! 236: case 8:
! 237: return (cp[h] == 0);
! 238: case 4:
! 239: return ((cp[h >> 1] & (0x0f << ((h & 0x1) << 2))) == 0);
! 240: case 2:
! 241: return ((cp[h >> 2] & (0x03 << ((h & 0x3) << 1))) == 0);
! 242: case 1:
! 243: return ((cp[h >> 3] & (0x01 << (h & 0x7))) == 0);
! 244: }
! 245: }
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