ext2_balloc.c revision 311232
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_balloc.c 8.4 (Berkeley) 9/23/93 36 * $FreeBSD: stable/10/sys/fs/ext2fs/ext2_balloc.c 311232 2017-01-04 02:43:33Z pfg $ 37 */ 38 39#include <sys/param.h> 40#include <sys/systm.h> 41#include <sys/bio.h> 42#include <sys/buf.h> 43#include <sys/lock.h> 44#include <sys/mount.h> 45#include <sys/vnode.h> 46 47#include <fs/ext2fs/fs.h> 48#include <fs/ext2fs/inode.h> 49#include <fs/ext2fs/ext2fs.h> 50#include <fs/ext2fs/ext2_dinode.h> 51#include <fs/ext2fs/ext2_extern.h> 52#include <fs/ext2fs/ext2_mount.h> 53 54/* 55 * Balloc defines the structure of filesystem storage 56 * by allocating the physical blocks on a device given 57 * the inode and the logical block number in a file. 58 */ 59int 60ext2_balloc(struct inode *ip, e2fs_lbn_t lbn, int size, struct ucred *cred, 61 struct buf **bpp, int flags) 62{ 63 struct m_ext2fs *fs; 64 struct ext2mount *ump; 65 struct buf *bp, *nbp; 66 struct vnode *vp = ITOV(ip); 67 struct indir indirs[NIADDR + 2]; 68 e4fs_daddr_t nb, newb; 69 e2fs_daddr_t *bap, pref; 70 int osize, nsize, num, i, error; 71 72 *bpp = NULL; 73 if (lbn < 0) 74 return (EFBIG); 75 fs = ip->i_e2fs; 76 ump = ip->i_ump; 77 78 /* 79 * check if this is a sequential block allocation. 80 * If so, increment next_alloc fields to allow ext2_blkpref 81 * to make a good guess 82 */ 83 if (lbn == ip->i_next_alloc_block + 1) { 84 ip->i_next_alloc_block++; 85 ip->i_next_alloc_goal++; 86 } 87 /* 88 * The first NDADDR blocks are direct blocks 89 */ 90 if (lbn < NDADDR) { 91 nb = ip->i_db[lbn]; 92 /* 93 * no new block is to be allocated, and no need to expand 94 * the file 95 */ 96 if (nb != 0 && ip->i_size >= (lbn + 1) * fs->e2fs_bsize) { 97 error = bread(vp, lbn, fs->e2fs_bsize, NOCRED, &bp); 98 if (error) { 99 brelse(bp); 100 return (error); 101 } 102 bp->b_blkno = fsbtodb(fs, nb); 103 *bpp = bp; 104 return (0); 105 } 106 if (nb != 0) { 107 /* 108 * Consider need to reallocate a fragment. 109 */ 110 osize = fragroundup(fs, blkoff(fs, ip->i_size)); 111 nsize = fragroundup(fs, size); 112 if (nsize <= osize) { 113 error = bread(vp, lbn, osize, NOCRED, &bp); 114 if (error) { 115 brelse(bp); 116 return (error); 117 } 118 bp->b_blkno = fsbtodb(fs, nb); 119 } else { 120 /* 121 * Godmar thinks: this shouldn't happen w/o 122 * fragments 123 */ 124 printf("nsize %d(%d) > osize %d(%d) nb %d\n", 125 (int)nsize, (int)size, (int)osize, 126 (int)ip->i_size, (int)nb); 127 panic( 128 "ext2_balloc: Something is terribly wrong"); 129/* 130 * please note there haven't been any changes from here on - 131 * FFS seems to work. 132 */ 133 } 134 } else { 135 if (ip->i_size < (lbn + 1) * fs->e2fs_bsize) 136 nsize = fragroundup(fs, size); 137 else 138 nsize = fs->e2fs_bsize; 139 EXT2_LOCK(ump); 140 error = ext2_alloc(ip, lbn, 141 ext2_blkpref(ip, lbn, (int)lbn, &ip->i_db[0], 0), 142 nsize, cred, &newb); 143 if (error) 144 return (error); 145 bp = getblk(vp, lbn, nsize, 0, 0, 0); 146 bp->b_blkno = fsbtodb(fs, newb); 147 if (flags & BA_CLRBUF) 148 vfs_bio_clrbuf(bp); 149 } 150 ip->i_db[lbn] = dbtofsb(fs, bp->b_blkno); 151 ip->i_flag |= IN_CHANGE | IN_UPDATE; 152 *bpp = bp; 153 return (0); 154 } 155 /* 156 * Determine the number of levels of indirection. 157 */ 158 pref = 0; 159 if ((error = ext2_getlbns(vp, lbn, indirs, &num)) != 0) 160 return (error); 161#ifdef INVARIANTS 162 if (num < 1) 163 panic("ext2_balloc: ext2_getlbns returned indirect block"); 164#endif 165 /* 166 * Fetch the first indirect block allocating if necessary. 167 */ 168 --num; 169 nb = ip->i_ib[indirs[0].in_off]; 170 if (nb == 0) { 171 EXT2_LOCK(ump); 172 pref = ext2_blkpref(ip, lbn, indirs[0].in_off + 173 EXT2_NDIR_BLOCKS, &ip->i_db[0], 0); 174 if ((error = ext2_alloc(ip, lbn, pref, fs->e2fs_bsize, cred, 175 &newb))) 176 return (error); 177 nb = newb; 178 bp = getblk(vp, indirs[1].in_lbn, fs->e2fs_bsize, 0, 0, 0); 179 bp->b_blkno = fsbtodb(fs, newb); 180 vfs_bio_clrbuf(bp); 181 /* 182 * Write synchronously so that indirect blocks 183 * never point at garbage. 184 */ 185 if ((error = bwrite(bp)) != 0) { 186 ext2_blkfree(ip, nb, fs->e2fs_bsize); 187 return (error); 188 } 189 ip->i_ib[indirs[0].in_off] = newb; 190 ip->i_flag |= IN_CHANGE | IN_UPDATE; 191 } 192 /* 193 * Fetch through the indirect blocks, allocating as necessary. 194 */ 195 for (i = 1;;) { 196 error = bread(vp, 197 indirs[i].in_lbn, (int)fs->e2fs_bsize, NOCRED, &bp); 198 if (error) { 199 brelse(bp); 200 return (error); 201 } 202 bap = (e2fs_daddr_t *)bp->b_data; 203 nb = bap[indirs[i].in_off]; 204 if (i == num) 205 break; 206 i += 1; 207 if (nb != 0) { 208 bqrelse(bp); 209 continue; 210 } 211 EXT2_LOCK(ump); 212 if (pref == 0) 213 pref = ext2_blkpref(ip, lbn, indirs[i].in_off, bap, 214 bp->b_lblkno); 215 error = ext2_alloc(ip, lbn, pref, (int)fs->e2fs_bsize, cred, &newb); 216 if (error) { 217 brelse(bp); 218 return (error); 219 } 220 nb = newb; 221 nbp = getblk(vp, indirs[i].in_lbn, fs->e2fs_bsize, 0, 0, 0); 222 nbp->b_blkno = fsbtodb(fs, nb); 223 vfs_bio_clrbuf(nbp); 224 /* 225 * Write synchronously so that indirect blocks 226 * never point at garbage. 227 */ 228 if ((error = bwrite(nbp)) != 0) { 229 ext2_blkfree(ip, nb, fs->e2fs_bsize); 230 EXT2_UNLOCK(ump); 231 brelse(bp); 232 return (error); 233 } 234 bap[indirs[i - 1].in_off] = nb; 235 /* 236 * If required, write synchronously, otherwise use 237 * delayed write. 238 */ 239 if (flags & IO_SYNC) { 240 bwrite(bp); 241 } else { 242 if (bp->b_bufsize == fs->e2fs_bsize) 243 bp->b_flags |= B_CLUSTEROK; 244 bdwrite(bp); 245 } 246 } 247 /* 248 * Get the data block, allocating if necessary. 249 */ 250 if (nb == 0) { 251 EXT2_LOCK(ump); 252 pref = ext2_blkpref(ip, lbn, indirs[i].in_off, &bap[0], 253 bp->b_lblkno); 254 if ((error = ext2_alloc(ip, 255 lbn, pref, (int)fs->e2fs_bsize, cred, &newb)) != 0) { 256 brelse(bp); 257 return (error); 258 } 259 nb = newb; 260 nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0); 261 nbp->b_blkno = fsbtodb(fs, nb); 262 if (flags & BA_CLRBUF) 263 vfs_bio_clrbuf(nbp); 264 bap[indirs[i].in_off] = nb; 265 /* 266 * If required, write synchronously, otherwise use 267 * delayed write. 268 */ 269 if (flags & IO_SYNC) { 270 bwrite(bp); 271 } else { 272 if (bp->b_bufsize == fs->e2fs_bsize) 273 bp->b_flags |= B_CLUSTEROK; 274 bdwrite(bp); 275 } 276 *bpp = nbp; 277 return (0); 278 } 279 brelse(bp); 280 if (flags & BA_CLRBUF) { 281 int seqcount = (flags & BA_SEQMASK) >> BA_SEQSHIFT; 282 283 if (seqcount && (vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) { 284 error = cluster_read(vp, ip->i_size, lbn, 285 (int)fs->e2fs_bsize, NOCRED, 286 MAXBSIZE, seqcount, 0, &nbp); 287 } else { 288 error = bread(vp, lbn, (int)fs->e2fs_bsize, NOCRED, &nbp); 289 } 290 if (error) { 291 brelse(nbp); 292 return (error); 293 } 294 } else { 295 nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0); 296 nbp->b_blkno = fsbtodb(fs, nb); 297 } 298 *bpp = nbp; 299 return (0); 300} 301