ffs_balloc.c revision 24775
1/* 2 * Copyright (c) 1982, 1986, 1989, 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 * @(#)ffs_balloc.c 8.8 (Berkeley) 6/16/95 34 * $Id: ffs_balloc.c,v 1.13 1997/02/22 09:47:01 peter Exp $ 35 */ 36 37#include <sys/param.h> 38#include <sys/systm.h> 39#include <sys/buf.h> 40#include <sys/proc.h> 41#include <sys/file.h> 42#include <sys/vnode.h> 43 44#include <vm/vm.h> 45 46#include <ufs/ufs/quota.h> 47#include <ufs/ufs/inode.h> 48#include <ufs/ufs/ufs_extern.h> 49 50#include <ufs/ffs/fs.h> 51#include <ufs/ffs/ffs_extern.h> 52 53/* 54 * Balloc defines the structure of file system storage 55 * by allocating the physical blocks on a device given 56 * the inode and the logical block number in a file. 57 */ 58int 59ffs_balloc(ip, lbn, size, cred, bpp, flags) 60 register struct inode *ip; 61 register ufs_daddr_t lbn; 62 int size; 63 struct ucred *cred; 64 struct buf **bpp; 65 int flags; 66{ 67 register struct fs *fs; 68 register ufs_daddr_t nb; 69 struct buf *bp, *nbp; 70 struct vnode *vp = ITOV(ip); 71 struct indir indirs[NIADDR + 2]; 72 ufs_daddr_t newb, *bap, pref; 73 int deallocated, osize, nsize, num, i, error; 74 ufs_daddr_t *allocib, *blkp, *allocblk, allociblk[NIADDR + 1]; 75 76 *bpp = NULL; 77 if (lbn < 0) 78 return (EFBIG); 79 fs = ip->i_fs; 80 81 /* 82 * If the next write will extend the file into a new block, 83 * and the file is currently composed of a fragment 84 * this fragment has to be extended to be a full block. 85 */ 86 nb = lblkno(fs, ip->i_size); 87 if (nb < NDADDR && nb < lbn) { 88 osize = blksize(fs, ip, nb); 89 if (osize < fs->fs_bsize && osize > 0) { 90 error = ffs_realloccg(ip, nb, 91 ffs_blkpref(ip, nb, (int)nb, &ip->i_db[0]), 92 osize, (int)fs->fs_bsize, cred, &bp); 93 if (error) 94 return (error); 95 ip->i_size = smalllblktosize(fs, nb + 1); 96 ip->i_db[nb] = dbtofsb(fs, bp->b_blkno); 97 ip->i_flag |= IN_CHANGE | IN_UPDATE; 98 if (flags & B_SYNC) 99 bwrite(bp); 100 else 101 bawrite(bp); 102 } 103 } 104 /* 105 * The first NDADDR blocks are direct blocks 106 */ 107 if (lbn < NDADDR) { 108 nb = ip->i_db[lbn]; 109 if (nb != 0 && ip->i_size >= smalllblktosize(fs, lbn + 1)) { 110 error = bread(vp, lbn, fs->fs_bsize, NOCRED, &bp); 111 if (error) { 112 brelse(bp); 113 return (error); 114 } 115 bp->b_blkno = fsbtodb(fs, nb); 116 *bpp = bp; 117 return (0); 118 } 119 if (nb != 0) { 120 /* 121 * Consider need to reallocate a fragment. 122 */ 123 osize = fragroundup(fs, blkoff(fs, ip->i_size)); 124 nsize = fragroundup(fs, size); 125 if (nsize <= osize) { 126 error = bread(vp, lbn, osize, NOCRED, &bp); 127 if (error) { 128 brelse(bp); 129 return (error); 130 } 131 bp->b_blkno = fsbtodb(fs, nb); 132 } else { 133 error = ffs_realloccg(ip, lbn, 134 ffs_blkpref(ip, lbn, (int)lbn, 135 &ip->i_db[0]), osize, nsize, cred, &bp); 136 if (error) 137 return (error); 138 } 139 } else { 140 if (ip->i_size < smalllblktosize(fs, lbn + 1)) 141 nsize = fragroundup(fs, size); 142 else 143 nsize = fs->fs_bsize; 144 error = ffs_alloc(ip, lbn, 145 ffs_blkpref(ip, lbn, (int)lbn, &ip->i_db[0]), 146 nsize, cred, &newb); 147 if (error) 148 return (error); 149 bp = getblk(vp, lbn, nsize, 0, 0); 150 bp->b_blkno = fsbtodb(fs, newb); 151 if (flags & B_CLRBUF) 152 vfs_bio_clrbuf(bp); 153 } 154 ip->i_db[lbn] = dbtofsb(fs, bp->b_blkno); 155 ip->i_flag |= IN_CHANGE | IN_UPDATE; 156 *bpp = bp; 157 return (0); 158 } 159 /* 160 * Determine the number of levels of indirection. 161 */ 162 pref = 0; 163 if (error = ufs_getlbns(vp, lbn, indirs, &num)) 164 return(error); 165#ifdef DIAGNOSTIC 166 if (num < 1) 167 panic ("ffs_balloc: ufs_bmaparray returned indirect block"); 168#endif 169 /* 170 * Fetch the first indirect block allocating if necessary. 171 */ 172 --num; 173 nb = ip->i_ib[indirs[0].in_off]; 174 allocib = NULL; 175 allocblk = allociblk; 176 if (nb == 0) { 177 pref = ffs_blkpref(ip, lbn, 0, (ufs_daddr_t *)0); 178 if (error = ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, 179 cred, &newb)) 180 return (error); 181 nb = newb; 182 *allocblk++ = nb; 183 bp = getblk(vp, indirs[1].in_lbn, fs->fs_bsize, 0, 0); 184 bp->b_blkno = fsbtodb(fs, nb); 185 vfs_bio_clrbuf(bp); 186 /* 187 * Write synchronously so that indirect blocks 188 * never point at garbage. 189 */ 190 if (error = bwrite(bp)) 191 goto fail; 192 allocib = &ip->i_ib[indirs[0].in_off]; 193 *allocib = nb; 194 ip->i_flag |= IN_CHANGE | IN_UPDATE; 195 } 196 /* 197 * Fetch through the indirect blocks, allocating as necessary. 198 */ 199 for (i = 1;;) { 200 error = bread(vp, 201 indirs[i].in_lbn, (int)fs->fs_bsize, NOCRED, &bp); 202 if (error) { 203 brelse(bp); 204 goto fail; 205 } 206 bap = (ufs_daddr_t *)bp->b_data; 207 nb = bap[indirs[i].in_off]; 208 if (i == num) 209 break; 210 i += 1; 211 if (nb != 0) { 212 bqrelse(bp); 213 continue; 214 } 215 if (pref == 0) 216 pref = ffs_blkpref(ip, lbn, 0, (ufs_daddr_t *)0); 217 if (error = 218 ffs_alloc(ip, lbn, pref, (int)fs->fs_bsize, cred, &newb)) { 219 brelse(bp); 220 goto fail; 221 } 222 nb = newb; 223 *allocblk++ = nb; 224 nbp = getblk(vp, indirs[i].in_lbn, fs->fs_bsize, 0, 0); 225 nbp->b_blkno = fsbtodb(fs, nb); 226 vfs_bio_clrbuf(nbp); 227 /* 228 * Write synchronously so that indirect blocks 229 * never point at garbage. 230 */ 231 if (error = bwrite(nbp)) { 232 brelse(bp); 233 goto fail; 234 } 235 bap[indirs[i - 1].in_off] = nb; 236 /* 237 * If required, write synchronously, otherwise use 238 * delayed write. 239 */ 240 if (flags & B_SYNC) { 241 bwrite(bp); 242 } else { 243 bdwrite(bp); 244 } 245 } 246 /* 247 * Get the data block, allocating if necessary. 248 */ 249 if (nb == 0) { 250 pref = ffs_blkpref(ip, lbn, indirs[i].in_off, &bap[0]); 251 error = ffs_alloc(ip, 252 lbn, pref, (int)fs->fs_bsize, cred, &newb); 253 if (error) { 254 brelse(bp); 255 goto fail; 256 } 257 nb = newb; 258 *allocblk++ = nb; 259 nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0); 260 nbp->b_blkno = fsbtodb(fs, nb); 261 if (flags & B_CLRBUF) 262 vfs_bio_clrbuf(nbp); 263 bap[indirs[i].in_off] = nb; 264 /* 265 * If required, write synchronously, otherwise use 266 * delayed write. 267 */ 268 if (flags & B_SYNC) { 269 bwrite(bp); 270 } else { 271 bdwrite(bp); 272 } 273 *bpp = nbp; 274 return (0); 275 } 276 brelse(bp); 277 if (flags & B_CLRBUF) { 278 error = bread(vp, lbn, (int)fs->fs_bsize, NOCRED, &nbp); 279 if (error) { 280 brelse(nbp); 281 goto fail; 282 } 283 } else { 284 nbp = getblk(vp, lbn, fs->fs_bsize, 0, 0); 285 nbp->b_blkno = fsbtodb(fs, nb); 286 } 287 *bpp = nbp; 288 return (0); 289fail: 290 /* 291 * If we have failed part way through block allocation, we 292 * have to deallocate any indirect blocks that we have allocated. 293 */ 294 for (deallocated = 0, blkp = allociblk; blkp < allocblk; blkp++) { 295 ffs_blkfree(ip, *blkp, fs->fs_bsize); 296 deallocated += fs->fs_bsize; 297 } 298 if (allocib != NULL) 299 *allocib = 0; 300 if (deallocated) { 301#ifdef QUOTA 302 /* 303 * Restore user's disk quota because allocation failed. 304 */ 305 (void) chkdq(ip, (long)-btodb(deallocated), cred, FORCE); 306#endif 307 ip->i_blocks -= btodb(deallocated); 308 ip->i_flag |= IN_CHANGE | IN_UPDATE; 309 } 310 return (error); 311} 312