sys/fs/ext2fs/ext2_balloc.c

   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  * $FreeBSD$
  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  */
  59 int
  60 ext2_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 }