/* $OpenBSD: ffs_subr.c,v 1.18 2006/06/17 16:30:58 miod Exp $ */ /* $NetBSD: ffs_subr.c,v 1.6 1996/03/17 02:16:23 christos Exp $ */ /* * Copyright (c) 1982, 1986, 1989, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)ffs_subr.c 8.2 (Berkeley) 9/21/93 */ #include #include #ifdef _KERNEL #include #include #include #include #include #include #include #include #include /* * Return buffer with the contents of block "offset" from the beginning of * directory "ip". If "res" is non-zero, fill it in with a pointer to the * remaining space in the directory. */ int ffs_bufatoff(struct inode *ip, off_t offset, char **res, struct buf **bpp) { struct fs *fs; struct vnode *vp; struct buf *bp; daddr_t lbn; int bsize, error; vp = ITOV(ip); fs = ip->i_fs; lbn = lblkno(fs, offset); bsize = blksize(fs, ip, lbn); *bpp = NULL; if ((error = bread(vp, lbn, bsize, NOCRED, &bp)) != 0) { brelse(bp); return (error); } if (res) *res = (char *)bp->b_data + blkoff(fs, offset); *bpp = bp; return (0); } #else /* Prototypes for userland */ void ffs_fragacct(struct fs *, int, int32_t[], int); int ffs_isfreeblock(struct fs *, unsigned char *, daddr_t); int ffs_isblock(struct fs *, unsigned char *, daddr_t); void ffs_clrblock(struct fs *, u_char *, daddr_t); void ffs_setblock(struct fs *, unsigned char *, daddr_t); __dead void panic(const char *, ...); #endif /* * Update the frsum fields to reflect addition or deletion * of some frags. */ void ffs_fragacct(struct fs *fs, int fragmap, int32_t fraglist[], int cnt) { int inblk; int field, subfield; int siz, pos; inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1; fragmap <<= 1; for (siz = 1; siz < fs->fs_frag; siz++) { if ((inblk & (1 << (siz + (fs->fs_frag % NBBY)))) == 0) continue; field = around[siz]; subfield = inside[siz]; for (pos = siz; pos <= fs->fs_frag; pos++) { if ((fragmap & field) == subfield) { fraglist[siz] += cnt; pos += siz; field <<= siz; subfield <<= siz; } field <<= 1; subfield <<= 1; } } } #if defined(_KERNEL) && defined(DIAGNOSTIC) void ffs_checkoverlap(struct buf *bp, struct inode *ip) { struct buf *ebp, *ep; daddr_t start, last; struct vnode *vp; ebp = &buf[nbuf]; start = bp->b_blkno; last = start + btodb(bp->b_bcount) - 1; for (ep = buf; ep < ebp; ep++) { if (ep == bp || (ep->b_flags & B_INVAL) || ep->b_vp == NULLVP) continue; if (VOP_BMAP(ep->b_vp, (daddr_t)0, &vp, (daddr_t)0, NULL)) continue; if (vp != ip->i_devvp) continue; /* look for overlap */ if (ep->b_bcount == 0 || ep->b_blkno > last || ep->b_blkno + btodb(ep->b_bcount) <= start) continue; vprint("Disk overlap", vp); (void)printf("\tstart %d, end %d overlap start %d, end %ld\n", start, last, ep->b_blkno, ep->b_blkno + btodb(ep->b_bcount) - 1); panic("Disk buffer overlap"); } } #endif /* DIAGNOSTIC */ /* * block operations * * check if a block is available */ int ffs_isblock(struct fs *fs, unsigned char *cp, daddr_t h) { unsigned char mask; switch ((int)fs->fs_frag) { default: case 8: return (cp[h] == 0xff); case 4: mask = 0x0f << ((h & 0x1) << 2); return ((cp[h >> 1] & mask) == mask); case 2: mask = 0x03 << ((h & 0x3) << 1); return ((cp[h >> 2] & mask) == mask); case 1: mask = 0x01 << (h & 0x7); return ((cp[h >> 3] & mask) == mask); } } /* * take a block out of the map */ void ffs_clrblock(struct fs *fs, u_char *cp, daddr_t h) { switch ((int)fs->fs_frag) { default: case 8: cp[h] = 0; return; case 4: cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2)); return; case 2: cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1)); return; case 1: cp[h >> 3] &= ~(0x01 << (h & 0x7)); return; } } /* * put a block into the map */ void ffs_setblock(struct fs *fs, unsigned char *cp, daddr_t h) { switch ((int)fs->fs_frag) { default: case 8: cp[h] = 0xff; return; case 4: cp[h >> 1] |= (0x0f << ((h & 0x1) << 2)); return; case 2: cp[h >> 2] |= (0x03 << ((h & 0x3) << 1)); return; case 1: cp[h >> 3] |= (0x01 << (h & 0x7)); return; } } /* * check if a block is free */ int ffs_isfreeblock(struct fs *fs, unsigned char *cp, daddr_t h) { switch ((int)fs->fs_frag) { default: case 8: return (cp[h] == 0); case 4: return ((cp[h >> 1] & (0x0f << ((h & 0x1) << 2))) == 0); case 2: return ((cp[h >> 2] & (0x03 << ((h & 0x3) << 1))) == 0); case 1: return ((cp[h >> 3] & (0x01 << (h & 0x7))) == 0); } }