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  * 3. 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 static int
  55 ext2_ext_balloc(struct inode *ip, uint32_t lbn, int size,
  56     struct ucred *cred, struct buf **bpp, int flags)
  57 {
  58         struct m_ext2fs *fs;
  59         struct buf *bp = NULL;
  60         struct vnode *vp = ITOV(ip);
  61         uint32_t nb;
  62         int osize, nsize, blks, error, allocated;
  63
  64         fs = ip->i_e2fs;
  65         blks = howmany(size, fs->e2fs_bsize);
  66
  67         error = ext4_ext_get_blocks(ip, lbn, blks, cred, NULL, &allocated, &nb);
  68         if (error)
  69                 return (error);
  70
  71         if (allocated) {
  72                 if (ip->i_size < (lbn + 1) * fs->e2fs_bsize)
  73                         nsize = fragroundup(fs, size);
  74                 else
  75                         nsize = fs->e2fs_bsize;
  76
  77                 bp = getblk(vp, lbn, nsize, 0, 0, 0);
  78                 if(!bp)
  79                         return (EIO);
  80
  81                 bp->b_blkno = fsbtodb(fs, nb);
  82                 if (flags & BA_CLRBUF)
  83                         vfs_bio_clrbuf(bp);
  84         } else {
  85                 if (ip->i_size >= (lbn + 1) * fs->e2fs_bsize) {
  86
  87                         error = bread(vp, lbn, fs->e2fs_bsize, NOCRED, &bp);
  88                         if (error) {
  89                                 brelse(bp);
  90                                 return (error);
  91                         }
  92                         bp->b_blkno = fsbtodb(fs, nb);
  93                         *bpp = bp;
  94                         return (0);
  95                 }
  96
  97                 /*
  98                  * Consider need to reallocate a fragment.
  99                  */
 100                 osize = fragroundup(fs, blkoff(fs, ip->i_size));
 101                 nsize = fragroundup(fs, size);
 102                 if (nsize <= osize) {
 103                         error = bread(vp, lbn, osize, NOCRED, &bp);
 104                         if (error) {
 105                                 brelse(bp);
 106                                 return (error);
 107                         }
 108                         bp->b_blkno = fsbtodb(fs, nb);
 109                 } else {
 110                         error = bread(vp, lbn, fs->e2fs_bsize, NOCRED, &bp);
 111                         if (error) {
 112                                 brelse(bp);
 113                                 return (error);
 114                         }
 115                         bp->b_blkno = fsbtodb(fs, nb);
 116                 }
 117         }
 118
 119         *bpp = bp;
 120
 121         return (error);
 122 }
 123
 124 /*
 125  * Balloc defines the structure of filesystem storage
 126  * by allocating the physical blocks on a device given
 127  * the inode and the logical block number in a file.
 128  */
 129 int
 130 ext2_balloc(struct inode *ip, e2fs_lbn_t lbn, int size, struct ucred *cred,
 131     struct buf **bpp, int flags)
 132 {
 133         struct m_ext2fs *fs;
 134         struct ext2mount *ump;
 135         struct buf *bp, *nbp;
 136         struct vnode *vp = ITOV(ip);
 137         struct indir indirs[EXT2_NIADDR + 2];
 138         e4fs_daddr_t nb, newb;
 139         e2fs_daddr_t *bap, pref;
 140         int osize, nsize, num, i, error;
 141
 142         *bpp = NULL;
 143         if (lbn < 0)
 144                 return (EFBIG);
 145         fs = ip->i_e2fs;
 146         ump = ip->i_ump;
 147
 148         /*
 149          * check if this is a sequential block allocation.
 150          * If so, increment next_alloc fields to allow ext2_blkpref
 151          * to make a good guess
 152          */
 153         if (lbn == ip->i_next_alloc_block + 1) {
 154                 ip->i_next_alloc_block++;
 155                 ip->i_next_alloc_goal++;
 156         }
 157
 158         if (ip->i_flag & IN_E4EXTENTS)
 159                 return (ext2_ext_balloc(ip, lbn, size, cred, bpp, flags));
 160
 161         /*
 162          * The first EXT2_NDADDR blocks are direct blocks
 163          */
 164         if (lbn < EXT2_NDADDR) {
 165                 nb = ip->i_db[lbn];
 166                 /*
 167                  * no new block is to be allocated, and no need to expand
 168                  * the file
 169                  */
 170                 if (nb != 0 && ip->i_size >= (lbn + 1) * fs->e2fs_bsize) {
 171                         error = bread(vp, lbn, fs->e2fs_bsize, NOCRED, &bp);
 172                         if (error) {
 173                                 brelse(bp);
 174                                 return (error);
 175                         }
 176                         bp->b_blkno = fsbtodb(fs, nb);
 177                         *bpp = bp;
 178                         return (0);
 179                 }
 180                 if (nb != 0) {
 181                         /*
 182                          * Consider need to reallocate a fragment.
 183                          */
 184                         osize = fragroundup(fs, blkoff(fs, ip->i_size));
 185                         nsize = fragroundup(fs, size);
 186                         if (nsize <= osize) {
 187                                 error = bread(vp, lbn, osize, NOCRED, &bp);
 188                                 if (error) {
 189                                         brelse(bp);
 190                                         return (error);
 191                                 }
 192                                 bp->b_blkno = fsbtodb(fs, nb);
 193                         } else {
 194                                 /*
 195                                  * Godmar thinks: this shouldn't happen w/o
 196                                  * fragments
 197                                  */
 198                                 printf("nsize %d(%d) > osize %d(%d) nb %d\n",
 199                                     (int)nsize, (int)size, (int)osize,
 200                                     (int)ip->i_size, (int)nb);
 201                                 panic(
 202                                     "ext2_balloc: Something is terribly wrong");
 203 /*
 204  * please note there haven't been any changes from here on -
 205  * FFS seems to work.
 206  */
 207                         }
 208                 } else {
 209                         if (ip->i_size < (lbn + 1) * fs->e2fs_bsize)
 210                                 nsize = fragroundup(fs, size);
 211                         else
 212                                 nsize = fs->e2fs_bsize;
 213                         EXT2_LOCK(ump);
 214                         error = ext2_alloc(ip, lbn,
 215                             ext2_blkpref(ip, lbn, (int)lbn, &ip->i_db[0], 0),
 216                             nsize, cred, &newb);
 217                         if (error)
 218                                 return (error);
 219                         bp = getblk(vp, lbn, nsize, 0, 0, 0);
 220                         bp->b_blkno = fsbtodb(fs, newb);
 221                         if (flags & BA_CLRBUF)
 222                                 vfs_bio_clrbuf(bp);
 223                 }
 224                 ip->i_db[lbn] = dbtofsb(fs, bp->b_blkno);
 225                 ip->i_flag |= IN_CHANGE | IN_UPDATE;
 226                 *bpp = bp;
 227                 return (0);
 228         }
 229         /*
 230          * Determine the number of levels of indirection.
 231          */
 232         pref = 0;
 233         if ((error = ext2_getlbns(vp, lbn, indirs, &num)) != 0)
 234                 return (error);
 235 #ifdef INVARIANTS
 236         if (num < 1)
 237                 panic("ext2_balloc: ext2_getlbns returned indirect block");
 238 #endif
 239         /*
 240          * Fetch the first indirect block allocating if necessary.
 241          */
 242         --num;
 243         nb = ip->i_ib[indirs[0].in_off];
 244         if (nb == 0) {
 245                 EXT2_LOCK(ump);
 246                 pref = ext2_blkpref(ip, lbn, indirs[0].in_off +
 247                     EXT2_NDIR_BLOCKS, &ip->i_db[0], 0);
 248                 if ((error = ext2_alloc(ip, lbn, pref, fs->e2fs_bsize, cred,
 249                     &newb)))
 250                         return (error);
 251                 nb = newb;
 252                 bp = getblk(vp, indirs[1].in_lbn, fs->e2fs_bsize, 0, 0, 0);
 253                 bp->b_blkno = fsbtodb(fs, newb);
 254                 vfs_bio_clrbuf(bp);
 255                 /*
 256                  * Write synchronously so that indirect blocks
 257                  * never point at garbage.
 258                  */
 259                 if ((error = bwrite(bp)) != 0) {
 260                         ext2_blkfree(ip, nb, fs->e2fs_bsize);
 261                         return (error);
 262                 }
 263                 ip->i_ib[indirs[0].in_off] = newb;
 264                 ip->i_flag |= IN_CHANGE | IN_UPDATE;
 265         }
 266         /*
 267          * Fetch through the indirect blocks, allocating as necessary.
 268          */
 269         for (i = 1;;) {
 270                 error = bread(vp,
 271                     indirs[i].in_lbn, (int)fs->e2fs_bsize, NOCRED, &bp);
 272                 if (error) {
 273                         brelse(bp);
 274                         return (error);
 275                 }
 276                 bap = (e2fs_daddr_t *)bp->b_data;
 277                 nb = bap[indirs[i].in_off];
 278                 if (i == num)
 279                         break;
 280                 i += 1;
 281                 if (nb != 0) {
 282                         bqrelse(bp);
 283                         continue;
 284                 }
 285                 EXT2_LOCK(ump);
 286                 if (pref == 0)
 287                         pref = ext2_blkpref(ip, lbn, indirs[i].in_off, bap,
 288                             bp->b_lblkno);
 289                 error = ext2_alloc(ip, lbn, pref, (int)fs->e2fs_bsize, cred, &newb);
 290                 if (error) {
 291                         brelse(bp);
 292                         return (error);
 293                 }
 294                 nb = newb;
 295                 nbp = getblk(vp, indirs[i].in_lbn, fs->e2fs_bsize, 0, 0, 0);
 296                 nbp->b_blkno = fsbtodb(fs, nb);
 297                 vfs_bio_clrbuf(nbp);
 298                 /*
 299                  * Write synchronously so that indirect blocks
 300                  * never point at garbage.
 301                  */
 302                 if ((error = bwrite(nbp)) != 0) {
 303                         ext2_blkfree(ip, nb, fs->e2fs_bsize);
 304                         EXT2_UNLOCK(ump);
 305                         brelse(bp);
 306                         return (error);
 307                 }
 308                 bap[indirs[i - 1].in_off] = nb;
 309                 /*
 310                  * If required, write synchronously, otherwise use
 311                  * delayed write.
 312                  */
 313                 if (flags & IO_SYNC) {
 314                         bwrite(bp);
 315                 } else {
 316                         if (bp->b_bufsize == fs->e2fs_bsize)
 317                                 bp->b_flags |= B_CLUSTEROK;
 318                         bdwrite(bp);
 319                 }
 320         }
 321         /*
 322          * Get the data block, allocating if necessary.
 323          */
 324         if (nb == 0) {
 325                 EXT2_LOCK(ump);
 326                 pref = ext2_blkpref(ip, lbn, indirs[i].in_off, &bap[0],
 327                     bp->b_lblkno);
 328                 if ((error = ext2_alloc(ip,
 329                     lbn, pref, (int)fs->e2fs_bsize, cred, &newb)) != 0) {
 330                         brelse(bp);
 331                         return (error);
 332                 }
 333                 nb = newb;
 334                 nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
 335                 nbp->b_blkno = fsbtodb(fs, nb);
 336                 if (flags & BA_CLRBUF)
 337                         vfs_bio_clrbuf(nbp);
 338                 bap[indirs[i].in_off] = nb;
 339                 /*
 340                  * If required, write synchronously, otherwise use
 341                  * delayed write.
 342                  */
 343                 if (flags & IO_SYNC) {
 344                         bwrite(bp);
 345                 } else {
 346                         if (bp->b_bufsize == fs->e2fs_bsize)
 347                                 bp->b_flags |= B_CLUSTEROK;
 348                         bdwrite(bp);
 349                 }
 350                 *bpp = nbp;
 351                 return (0);
 352         }
 353         brelse(bp);
 354         if (flags & BA_CLRBUF) {
 355                 int seqcount = (flags & BA_SEQMASK) >> BA_SEQSHIFT;
 356
 357                 if (seqcount && (vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
 358                         error = cluster_read(vp, ip->i_size, lbn,
 359                             (int)fs->e2fs_bsize, NOCRED,
 360                             MAXBSIZE, seqcount, 0, &nbp);
 361                 } else {
 362                         error = bread(vp, lbn, (int)fs->e2fs_bsize, NOCRED, &nbp);
 363                 }
 364                 if (error) {
 365                         brelse(nbp);
 366                         return (error);
 367                 }
 368         } else {
 369                 nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, 0, 0);
 370                 nbp->b_blkno = fsbtodb(fs, nb);
 371         }
 372         *bpp = nbp;
 373         return (0);
 374 }