1 /*- 2 * modified for Lites 1.1 3 * 4 * Aug 1995, Godmar Back (gback@cs.utah.edu) 5 * University of Utah, Department of Computer Science 6 */ 7 /*- 8 * Copyright (c) 1982, 1986, 1989, 1993 9 * The Regents of the University of California. All rights reserved. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 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 * @(#)ffs_subr.c 8.2 (Berkeley) 9/21/93 36 * $FreeBSD$ 37 */ 38 39 #include <sys/param.h> 40 41 #include <sys/proc.h> 42 #include <sys/systm.h> 43 #include <sys/bio.h> 44 #include <sys/buf.h> 45 #include <sys/lock.h> 46 #include <sys/ucred.h> 47 #include <sys/vnode.h> 48 49 #include <fs/ext2fs/inode.h> 50 #include <fs/ext2fs/ext2_extern.h> 51 #include <fs/ext2fs/ext2fs.h> 52 #include <fs/ext2fs/fs.h> 53 #include <fs/ext2fs/ext2_extents.h> 54 #include <fs/ext2fs/ext2_mount.h> 55 #include <fs/ext2fs/ext2_dinode.h> 56 57 #ifdef KDB 58 void ext2_checkoverlap(struct buf *, struct inode *); 59 #endif 60 61 /* 62 * Return buffer with the contents of block "offset" from the beginning of 63 * directory "ip". If "res" is non-zero, fill it in with a pointer to the 64 * remaining space in the directory. 65 */ 66 int 67 ext2_blkatoff(struct vnode *vp, off_t offset, char **res, struct buf **bpp) 68 { 69 struct inode *ip; 70 struct m_ext2fs *fs; 71 struct buf *bp; 72 e2fs_lbn_t lbn; 73 int bsize, error; 74 daddr_t newblk; 75 struct ext4_extent *ep; 76 struct ext4_extent_path path; 77 78 ip = VTOI(vp); 79 fs = ip->i_e2fs; 80 lbn = lblkno(fs, offset); 81 bsize = blksize(fs, ip, lbn); 82 *bpp = NULL; 83 84 /* 85 * The EXT4_EXTENTS requires special treatment, otherwise we can 86 * fall back to the normal path. 87 */ 88 if (!(ip->i_flags & EXT4_EXTENTS)) 89 goto normal; 90 91 memset(&path, 0, sizeof(path)); 92 if (ext4_ext_find_extent(fs, ip, lbn, &path) == NULL) 93 goto normal; 94 ep = path.ep_ext; 95 if (ep == NULL) 96 goto normal; 97 98 newblk = lbn - ep->e_blk + 99 (ep->e_start_lo | (daddr_t)ep->e_start_hi << 32); 100 101 if (path.ep_bp != NULL) { 102 brelse(path.ep_bp); 103 path.ep_bp = NULL; 104 } 105 error = bread(ip->i_devvp, fsbtodb(fs, newblk), bsize, NOCRED, &bp); 106 if (error != 0) { 107 brelse(bp); 108 return (error); 109 } 110 if (res) 111 *res = (char *)bp->b_data + blkoff(fs, offset); 112 /* 113 * If EXT4_EXTENTS is enabled we would get a wrong offset so 114 * reset b_offset here. 115 */ 116 bp->b_offset = lbn * bsize; 117 *bpp = bp; 118 return (0); 119 120 normal: 121 if (*bpp == NULL) { 122 if ((error = bread(vp, lbn, bsize, NOCRED, &bp)) != 0) { 123 brelse(bp); 124 return (error); 125 } 126 if (res) 127 *res = (char *)bp->b_data + blkoff(fs, offset); 128 *bpp = bp; 129 } 130 return (0); 131 } 132 133 #ifdef KDB 134 void 135 ext2_checkoverlap(struct buf *bp, struct inode *ip) 136 { 137 struct buf *ebp, *ep; 138 e4fs_daddr_t start, last; 139 struct vnode *vp; 140 141 ebp = &buf[nbuf]; 142 start = bp->b_blkno; 143 last = start + btodb(bp->b_bcount) - 1; 144 for (ep = buf; ep < ebp; ep++) { 145 if (ep == bp || (ep->b_flags & B_INVAL)) 146 continue; 147 vp = ip->i_ump->um_devvp; 148 /* look for overlap */ 149 if (ep->b_bcount == 0 || ep->b_blkno > last || 150 ep->b_blkno + btodb(ep->b_bcount) <= start) 151 continue; 152 vprint("Disk overlap", vp); 153 printf("\tstart %jd, end %jd overlap start %jd, end %jd\n", 154 (intmax_t)start, (intmax_t)last, (intmax_t)ep->b_blkno, 155 (intmax_t)(ep->b_blkno + btodb(ep->b_bcount) - 1)); 156 panic("ext2_checkoverlap: Disk buffer overlap"); 157 } 158 } 159 #endif /* KDB */ 160 161 /* 162 * Update the cluster map because of an allocation of free like ffs. 163 * 164 * Cnt == 1 means free; cnt == -1 means allocating. 165 */ 166 void 167 ext2_clusteracct(struct m_ext2fs *fs, char *bbp, int cg, daddr_t bno, int cnt) 168 { 169 int32_t *sump = fs->e2fs_clustersum[cg].cs_sum; 170 int32_t *lp; 171 int back, bit, end, forw, i, loc, start; 172 173 /* Initialize the cluster summary array. */ 174 if (fs->e2fs_clustersum[cg].cs_init == 0) { 175 int run = 0; 176 bit = 1; 177 loc = 0; 178 179 for (i = 0; i < fs->e2fs->e2fs_fpg; i++) { 180 if ((bbp[loc] & bit) == 0) 181 run++; 182 else if (run != 0) { 183 if (run > fs->e2fs_contigsumsize) 184 run = fs->e2fs_contigsumsize; 185 sump[run]++; 186 run = 0; 187 } 188 if ((i & (NBBY - 1)) != (NBBY - 1)) 189 bit <<= 1; 190 else { 191 loc++; 192 bit = 1; 193 } 194 } 195 if (run != 0) { 196 if (run > fs->e2fs_contigsumsize) 197 run = fs->e2fs_contigsumsize; 198 sump[run]++; 199 } 200 fs->e2fs_clustersum[cg].cs_init = 1; 201 } 202 203 if (fs->e2fs_contigsumsize <= 0) 204 return; 205 206 /* Find the size of the cluster going forward. */ 207 start = bno + 1; 208 end = start + fs->e2fs_contigsumsize; 209 if (end > fs->e2fs->e2fs_fpg) 210 end = fs->e2fs->e2fs_fpg; 211 loc = start / NBBY; 212 bit = 1 << (start % NBBY); 213 for (i = start; i < end; i++) { 214 if ((bbp[loc] & bit) != 0) 215 break; 216 if ((i & (NBBY - 1)) != (NBBY - 1)) 217 bit <<= 1; 218 else { 219 loc++; 220 bit = 1; 221 } 222 } 223 forw = i - start; 224 225 /* Find the size of the cluster going backward. */ 226 start = bno - 1; 227 end = start - fs->e2fs_contigsumsize; 228 if (end < 0) 229 end = -1; 230 loc = start / NBBY; 231 bit = 1 << (start % NBBY); 232 for (i = start; i > end; i--) { 233 if ((bbp[loc] & bit) != 0) 234 break; 235 if ((i & (NBBY - 1)) != 0) 236 bit >>= 1; 237 else { 238 loc--; 239 bit = 1 << (NBBY - 1); 240 } 241 } 242 back = start - i; 243 244 /* 245 * Account for old cluster and the possibly new forward and 246 * back clusters. 247 */ 248 i = back + forw + 1; 249 if (i > fs->e2fs_contigsumsize) 250 i = fs->e2fs_contigsumsize; 251 sump[i] += cnt; 252 if (back > 0) 253 sump[back] -= cnt; 254 if (forw > 0) 255 sump[forw] -= cnt; 256 257 /* Update cluster summary information. */ 258 lp = &sump[fs->e2fs_contigsumsize]; 259 for (i = fs->e2fs_contigsumsize; i > 0; i--) 260 if (*lp-- > 0) 261 break; 262 fs->e2fs_maxcluster[cg] = i; 263 } 264