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 #ident "$Id: vxfs_bmap.c,v 1.25 2002/01/02 23:36:55 hch Exp hch $"
  31
  32 /*
  33  * Veritas filesystem driver - filesystem to disk block mapping.
  34  */
  35 #include <linux/fs.h>
  36 #include <linux/kernel.h>
  37
  38 #include "vxfs.h"
  39 #include "vxfs_inode.h"
  40
  41
  42 #ifdef DIAGNOSTIC
  43 static void
  44 vxfs_typdump(struct vxfs_typed *typ)
  45 {
  46         printk(KERN_DEBUG "type=%Lu ", typ->vt_hdr >> VXFS_TYPED_TYPESHIFT);
  47         printk("offset=%Lx ", typ->vt_hdr & VXFS_TYPED_OFFSETMASK);
  48         printk("block=%x ", typ->vt_block);
  49         printk("size=%x\n", typ->vt_size);
  50 }
  51 #endif
  52
  53 /**
  54  * vxfs_bmap_ext4 - do bmap for ext4 extents
  55  * @ip:         pointer to the inode we do bmap for
  56  * @iblock:     logical block.
  57  *
  58  * Description:
  59  *   vxfs_bmap_ext4 performs the bmap operation for inodes with
  60  *   ext4-style extents (which are much like the traditional UNIX
  61  *   inode organisation).
  62  *
  63  * Returns:
  64  *   The physical block number on success, else Zero.
  65  */
  66 static daddr_t
  67 vxfs_bmap_ext4(struct inode *ip, long bn)
  68 {
  69         struct super_block *sb = ip->i_sb;
  70         struct vxfs_inode_info *vip = VXFS_INO(ip);
  71         unsigned long bsize = sb->s_blocksize;
  72         u32 indsize = vip->vii_ext4.ve4_indsize;
  73         int i;
  74
  75         if (indsize > sb->s_blocksize)
  76                 goto fail_size;
  77
  78         for (i = 0; i < VXFS_NDADDR; i++) {
  79                 struct direct *d = vip->vii_ext4.ve4_direct + i;
  80                 if (bn >= 0 && bn < d->size)
  81                         return (bn + d->extent);
  82                 bn -= d->size;
  83         }
  84
  85         if ((bn / (indsize * indsize * bsize / 4)) == 0) {
  86                 struct buffer_head *buf;
  87                 daddr_t bno;
  88                 u32 *indir;
  89
  90                 buf = sb_bread(sb, vip->vii_ext4.ve4_indir[0]);
  91                 if (!buf || !buffer_mapped(buf))
  92                         goto fail_buf;
  93
  94                 indir = (u32 *)buf->b_data;
  95                 bno = indir[(bn/indsize) % (indsize*bn)] + (bn%indsize);
  96
  97                 brelse(buf);
  98                 return bno;
  99         } else
 100                 printk(KERN_WARNING "no matching indir?");
 101
 102         return 0;
 103
 104 fail_size:
 105         printk("vxfs: indirect extent to big!\n");
 106 fail_buf:
 107         return 0;
 108 }
 109
 110 /**
 111  * vxfs_bmap_indir - recursion for vxfs_bmap_typed
 112  * @ip:         pointer to the inode we do bmap for
 113  * @indir:      indirect block we start reading at
 114  * @size:       size of the typed area to search
 115  * @block:      partially result from further searches
 116  *
 117  * Description:
 118  *   vxfs_bmap_indir reads a &struct vxfs_typed at @indir
 119  *   and performs the type-defined action.
 120  *
 121  * Return Value:
 122  *   The physical block number on success, else Zero.
 123  *
 124  * Note:
 125  *   Kernelstack is rare.  Unrecurse?
 126  */
 127 static daddr_t
 128 vxfs_bmap_indir(struct inode *ip, long indir, int size, long block)
 129 {
 130         struct buffer_head              *bp = NULL;
 131         daddr_t                         pblock = 0;
 132         int                             i;
 133
 134         for (i = 0; i < size * VXFS_TYPED_PER_BLOCK(ip->i_sb); i++) {
 135                 struct vxfs_typed       *typ;
 136                 int64_t                 off;
 137
 138                 bp = sb_bread(ip->i_sb,
 139                                 indir + (i / VXFS_TYPED_PER_BLOCK(ip->i_sb)));
 140                 if (!buffer_mapped(bp))
 141                         return 0;
 142
 143                 typ = ((struct vxfs_typed *)bp->b_data) +
 144                         (i % VXFS_TYPED_PER_BLOCK(ip->i_sb));
 145                 off = (typ->vt_hdr & VXFS_TYPED_OFFSETMASK);
 146
 147                 if (block < off) {
 148                         brelse(bp);
 149                         continue;
 150                 }
 151
 152                 switch ((u_int32_t)(typ->vt_hdr >> VXFS_TYPED_TYPESHIFT)) {
 153                 case VXFS_TYPED_INDIRECT:
 154                         pblock = vxfs_bmap_indir(ip, typ->vt_block,
 155                                         typ->vt_size, block - off);
 156                         if (pblock == -2)
 157                                 break;
 158                         goto out;
 159                 case VXFS_TYPED_DATA:
 160                         if ((block - off) >= typ->vt_size)
 161                                 break;
 162                         pblock = (typ->vt_block + block - off);
 163                         goto out;
 164                 case VXFS_TYPED_INDIRECT_DEV4:
 165                 case VXFS_TYPED_DATA_DEV4: {
 166                         struct vxfs_typed_dev4  *typ4 =
 167                                 (struct vxfs_typed_dev4 *)typ;
 168
 169                         printk(KERN_INFO "\n\nTYPED_DEV4 detected!\n");
 170                         printk(KERN_INFO "block: %Lu\tsize: %Ld\tdev: %d\n",
 171                                 typ4->vd4_block, typ4->vd4_size, typ4->vd4_dev);
 172                         goto fail;
 173                 }
 174                 default:
 175                         BUG();
 176                 }
 177                 brelse(bp);
 178         }
 179
 180 fail:
 181         pblock = 0;
 182 out:
 183         brelse(bp);
 184         return (pblock);
 185 }
 186
 187 /**
 188  * vxfs_bmap_typed - bmap for typed extents
 189  * @ip:         pointer to the inode we do bmap for
 190  * @iblock:     logical block
 191  *
 192  * Description:
 193  *   Performs the bmap operation for typed extents.
 194  *
 195  * Return Value:
 196  *   The physical block number on success, else Zero.
 197  */
 198 static daddr_t
 199 vxfs_bmap_typed(struct inode *ip, long iblock)
 200 {
 201         struct vxfs_inode_info          *vip = VXFS_INO(ip);
 202         daddr_t                         pblock = 0;
 203         int                             i;
 204
 205         for (i = 0; i < VXFS_NTYPED; i++) {
 206                 struct vxfs_typed       *typ = vip->vii_org.typed + i;
 207                 int64_t                 off = (typ->vt_hdr & VXFS_TYPED_OFFSETMASK);
 208
 209 #ifdef DIAGNOSTIC
 210                 vxfs_typdump(typ);
 211 #endif
 212                 if (iblock < off)
 213                         continue;
 214                 switch ((u_int32_t)(typ->vt_hdr >> VXFS_TYPED_TYPESHIFT)) {
 215                 case VXFS_TYPED_INDIRECT:
 216                         pblock = vxfs_bmap_indir(ip, typ->vt_block,
 217                                         typ->vt_size, iblock - off);
 218                         if (pblock == -2)
 219                                 break;
 220                         return (pblock);
 221                 case VXFS_TYPED_DATA:
 222                         if ((iblock - off) < typ->vt_size)
 223                                 return (typ->vt_block + iblock - off);
 224                         break;
 225                 case VXFS_TYPED_INDIRECT_DEV4:
 226                 case VXFS_TYPED_DATA_DEV4: {
 227                         struct vxfs_typed_dev4  *typ4 =
 228                                 (struct vxfs_typed_dev4 *)typ;
 229
 230                         printk(KERN_INFO "\n\nTYPED_DEV4 detected!\n");
 231                         printk(KERN_INFO "block: %Lu\tsize: %Ld\tdev: %d\n",
 232                                 typ4->vd4_block, typ4->vd4_size, typ4->vd4_dev);
 233                         return 0;
 234                 }
 235                 default:
 236                         BUG();
 237                 }
 238         }
 239
 240         return 0;
 241 }
 242
 243 /**
 244  * vxfs_bmap1 - vxfs-internal bmap operation
 245  * @ip:                 pointer to the inode we do bmap for
 246  * @iblock:             logical block
 247  *
 248  * Description:
 249  *   vxfs_bmap1 perfoms a logical to physical block mapping
 250  *   for vxfs-internal purposes.
 251  *
 252  * Return Value:
 253  *   The physical block number on success, else Zero.
 254  */
 255 daddr_t
 256 vxfs_bmap1(struct inode *ip, long iblock)
 257 {
 258         struct vxfs_inode_info          *vip = VXFS_INO(ip);
 259
 260         if (VXFS_ISEXT4(vip))
 261                 return vxfs_bmap_ext4(ip, iblock);
 262         if (VXFS_ISTYPED(vip))
 263                 return vxfs_bmap_typed(ip, iblock);
 264         if (VXFS_ISNONE(vip))
 265                 goto unsupp;
 266         if (VXFS_ISIMMED(vip))
 267                 goto unsupp;
 268
 269         printk(KERN_WARNING "vxfs: inode %ld has no valid orgtype (%x)\n",
 270                         ip->i_ino, vip->vii_orgtype);
 271         BUG();
 272
 273 unsupp:
 274         printk(KERN_WARNING "vxfs: inode %ld has an unsupported orgtype (%x)\n",
 275                         ip->i_ino, vip->vii_orgtype);
 276         return 0;
 277 }