fs/freevxfs/vxfs_bmap.c

   1 /*
   2  * Copyright (c) 2000-2001 Christoph Hellwig.
   3  * 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  *    without modification.
  11  * 2. The name of the author may not be used to endorse or promote products
  12  *    derived from this software without specific prior written permission.
  13  *
  14  * Alternatively, this software may be distributed under the terms of the
  15  * GNU General Public License ("GPL").
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  21  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 /*
  31  * Veritas filesystem driver - filesystem to disk block mapping.
  32  */
  33 #include <linux/fs.h>
  34 #include <linux/buffer_head.h>
  35 #include <linux/kernel.h>
  36
  37 #include "vxfs.h"
  38 #include "vxfs_inode.h"
  39
  40
  41 #ifdef DIAGNOSTIC
  42 static void
  43 vxfs_typdump(struct vxfs_typed *typ)
  44 {
  45         printk(KERN_DEBUG "type=%Lu ", typ->vt_hdr >> VXFS_TYPED_TYPESHIFT);
  46         printk("offset=%Lx ", typ->vt_hdr & VXFS_TYPED_OFFSETMASK);
  47         printk("block=%x ", typ->vt_block);
  48         printk("size=%x\n", typ->vt_size);
  49 }
  50 #endif
  51
  52 /**
  53  * vxfs_bmap_ext4 - do bmap for ext4 extents
  54  * @ip:         pointer to the inode we do bmap for
  55  * @iblock:     logical block.
  56  *
  57  * Description:
  58  *   vxfs_bmap_ext4 performs the bmap operation for inodes with
  59  *   ext4-style extents (which are much like the traditional UNIX
  60  *   inode organisation).
  61  *
  62  * Returns:
  63  *   The physical block number on success, else Zero.
  64  */
  65 static daddr_t
  66 vxfs_bmap_ext4(struct inode *ip, long bn)
  67 {
  68         struct super_block *sb = ip->i_sb;
  69         struct vxfs_inode_info *vip = VXFS_INO(ip);
  70         unsigned long bsize = sb->s_blocksize;
  71         u32 indsize = vip->vii_ext4.ve4_indsize;
  72         int i;
  73
  74         if (indsize > sb->s_blocksize)
  75                 goto fail_size;
  76
  77         for (i = 0; i < VXFS_NDADDR; i++) {
  78                 struct direct *d = vip->vii_ext4.ve4_direct + i;
  79                 if (bn >= 0 && bn < d->size)
  80                         return (bn + d->extent);
  81                 bn -= d->size;
  82         }
  83
  84         if ((bn / (indsize * indsize * bsize / 4)) == 0) {
  85                 struct buffer_head *buf;
  86                 daddr_t bno;
  87                 u32 *indir;
  88
  89                 buf = sb_bread(sb, vip->vii_ext4.ve4_indir[0]);
  90                 if (!buf || !buffer_mapped(buf))
  91                         goto fail_buf;
  92
  93                 indir = (u32 *)buf->b_data;
  94                 bno = indir[(bn/indsize) % (indsize*bn)] + (bn%indsize);
  95
  96                 brelse(buf);
  97                 return bno;
  98         } else
  99                 printk(KERN_WARNING "no matching indir?");
 100
 101         return 0;
 102
 103 fail_size:
 104         printk("vxfs: indirect extent too big!\n");
 105 fail_buf:
 106         return 0;
 107 }
 108
 109 /**
 110  * vxfs_bmap_indir - recursion for vxfs_bmap_typed
 111  * @ip:         pointer to the inode we do bmap for
 112  * @indir:      indirect block we start reading at
 113  * @size:       size of the typed area to search
 114  * @block:      partially result from further searches
 115  *
 116  * Description:
 117  *   vxfs_bmap_indir reads a &struct vxfs_typed at @indir
 118  *   and performs the type-defined action.
 119  *
 120  * Return Value:
 121  *   The physical block number on success, else Zero.
 122  *
 123  * Note:
 124  *   Kernelstack is rare.  Unrecurse?
 125  */
 126 static daddr_t
 127 vxfs_bmap_indir(struct inode *ip, long indir, int size, long block)
 128 {
 129         struct buffer_head              *bp = NULL;
 130         daddr_t                         pblock = 0;
 131         int                             i;
 132
 133         for (i = 0; i < size * VXFS_TYPED_PER_BLOCK(ip->i_sb); i++) {
 134                 struct vxfs_typed       *typ;
 135                 int64_t                 off;
 136
 137                 bp = sb_bread(ip->i_sb,
 138                                 indir + (i / VXFS_TYPED_PER_BLOCK(ip->i_sb)));
 139                 if (!buffer_mapped(bp))
 140                         return 0;
 141
 142                 typ = ((struct vxfs_typed *)bp->b_data) +
 143                         (i % VXFS_TYPED_PER_BLOCK(ip->i_sb));
 144                 off = (typ->vt_hdr & VXFS_TYPED_OFFSETMASK);
 145
 146                 if (block < off) {
 147                         brelse(bp);
 148                         continue;
 149                 }
 150
 151                 switch ((u_int32_t)(typ->vt_hdr >> VXFS_TYPED_TYPESHIFT)) {
 152                 case VXFS_TYPED_INDIRECT:
 153                         pblock = vxfs_bmap_indir(ip, typ->vt_block,
 154                                         typ->vt_size, block - off);
 155                         if (pblock == -2)
 156                                 break;
 157                         goto out;
 158                 case VXFS_TYPED_DATA:
 159                         if ((block - off) >= typ->vt_size)
 160                                 break;
 161                         pblock = (typ->vt_block + block - off);
 162                         goto out;
 163                 case VXFS_TYPED_INDIRECT_DEV4:
 164                 case VXFS_TYPED_DATA_DEV4: {
 165                         struct vxfs_typed_dev4  *typ4 =
 166                                 (struct vxfs_typed_dev4 *)typ;
 167
 168                         printk(KERN_INFO "\n\nTYPED_DEV4 detected!\n");
 169                         printk(KERN_INFO "block: %Lu\tsize: %Ld\tdev: %d\n",
 170                                (unsigned long long) typ4->vd4_block,
 171                                (unsigned long long) typ4->vd4_size,
 172                                typ4->vd4_dev);
 173                         goto fail;
 174                 }
 175                 default:
 176                         BUG();
 177                 }
 178                 brelse(bp);
 179         }
 180
 181 fail:
 182         pblock = 0;
 183 out:
 184         brelse(bp);
 185         return (pblock);
 186 }
 187
 188 /**
 189  * vxfs_bmap_typed - bmap for typed extents
 190  * @ip:         pointer to the inode we do bmap for
 191  * @iblock:     logical block
 192  *
 193  * Description:
 194  *   Performs the bmap operation for typed extents.
 195  *
 196  * Return Value:
 197  *   The physical block number on success, else Zero.
 198  */
 199 static daddr_t
 200 vxfs_bmap_typed(struct inode *ip, long iblock)
 201 {
 202         struct vxfs_inode_info          *vip = VXFS_INO(ip);
 203         daddr_t                         pblock = 0;
 204         int                             i;
 205
 206         for (i = 0; i < VXFS_NTYPED; i++) {
 207                 struct vxfs_typed       *typ = vip->vii_org.typed + i;
 208                 int64_t                 off = (typ->vt_hdr & VXFS_TYPED_OFFSETMASK);
 209
 210 #ifdef DIAGNOSTIC
 211                 vxfs_typdump(typ);
 212 #endif
 213                 if (iblock < off)
 214                         continue;
 215                 switch ((u_int32_t)(typ->vt_hdr >> VXFS_TYPED_TYPESHIFT)) {
 216                 case VXFS_TYPED_INDIRECT:
 217                         pblock = vxfs_bmap_indir(ip, typ->vt_block,
 218                                         typ->vt_size, iblock - off);
 219                         if (pblock == -2)
 220                                 break;
 221                         return (pblock);
 222                 case VXFS_TYPED_DATA:
 223                         if ((iblock - off) < typ->vt_size)
 224                                 return (typ->vt_block + iblock - off);
 225                         break;
 226                 case VXFS_TYPED_INDIRECT_DEV4:
 227                 case VXFS_TYPED_DATA_DEV4: {
 228                         struct vxfs_typed_dev4  *typ4 =
 229                                 (struct vxfs_typed_dev4 *)typ;
 230
 231                         printk(KERN_INFO "\n\nTYPED_DEV4 detected!\n");
 232                         printk(KERN_INFO "block: %Lu\tsize: %Ld\tdev: %d\n",
 233                                (unsigned long long) typ4->vd4_block,
 234                                (unsigned long long) typ4->vd4_size,
 235                                typ4->vd4_dev);
 236                         return 0;
 237                 }
 238                 default:
 239                         BUG();
 240                 }
 241         }
 242
 243         return 0;
 244 }
 245
 246 /**
 247  * vxfs_bmap1 - vxfs-internal bmap operation
 248  * @ip:                 pointer to the inode we do bmap for
 249  * @iblock:             logical block
 250  *
 251  * Description:
 252  *   vxfs_bmap1 perfoms a logical to physical block mapping
 253  *   for vxfs-internal purposes.
 254  *
 255  * Return Value:
 256  *   The physical block number on success, else Zero.
 257  */
 258 daddr_t
 259 vxfs_bmap1(struct inode *ip, long iblock)
 260 {
 261         struct vxfs_inode_info          *vip = VXFS_INO(ip);
 262
 263         if (VXFS_ISEXT4(vip))
 264                 return vxfs_bmap_ext4(ip, iblock);
 265         if (VXFS_ISTYPED(vip))
 266                 return vxfs_bmap_typed(ip, iblock);
 267         if (VXFS_ISNONE(vip))
 268                 goto unsupp;
 269         if (VXFS_ISIMMED(vip))
 270                 goto unsupp;
 271
 272         printk(KERN_WARNING "vxfs: inode %ld has no valid orgtype (%x)\n",
 273                         ip->i_ino, vip->vii_orgtype);
 274         BUG();
 275
 276 unsupp:
 277         printk(KERN_WARNING "vxfs: inode %ld has an unsupported orgtype (%x)\n",
 278                         ip->i_ino, vip->vii_orgtype);
 279         return 0;
 280 }