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 #include "vxfs_extern.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         struct vxfs_sb_info *sbi = VXFS_SBI(sb);
  72         unsigned long bsize = sb->s_blocksize;
  73         u32 indsize = fs32_to_cpu(sbi, vip->vii_ext4.ve4_indsize);
  74         int i;
  75
  76         if (indsize > sb->s_blocksize)
  77                 goto fail_size;
  78
  79         for (i = 0; i < VXFS_NDADDR; i++) {
  80                 struct direct *d = vip->vii_ext4.ve4_direct + i;
  81                 if (bn >= 0 && bn < fs32_to_cpu(sbi, d->size))
  82                         return (bn + fs32_to_cpu(sbi, d->extent));
  83                 bn -= fs32_to_cpu(sbi, d->size);
  84         }
  85
  86         if ((bn / (indsize * indsize * bsize / 4)) == 0) {
  87                 struct buffer_head *buf;
  88                 daddr_t bno;
  89                 __fs32 *indir;
  90
  91                 buf = sb_bread(sb,
  92                         fs32_to_cpu(sbi, vip->vii_ext4.ve4_indir[0]));
  93                 if (!buf || !buffer_mapped(buf))
  94                         goto fail_buf;
  95
  96                 indir = (__fs32 *)buf->b_data;
  97                 bno = fs32_to_cpu(sbi, indir[(bn / indsize) % (indsize * bn)]) +
  98                         (bn % indsize);
  99
 100                 brelse(buf);
 101                 return bno;
 102         } else
 103                 printk(KERN_WARNING "no matching indir?");
 104
 105         return 0;
 106
 107 fail_size:
 108         printk("vxfs: indirect extent too big!\n");
 109 fail_buf:
 110         return 0;
 111 }
 112
 113 /**
 114  * vxfs_bmap_indir - recursion for vxfs_bmap_typed
 115  * @ip:         pointer to the inode we do bmap for
 116  * @indir:      indirect block we start reading at
 117  * @size:       size of the typed area to search
 118  * @block:      partially result from further searches
 119  *
 120  * Description:
 121  *   vxfs_bmap_indir reads a &struct vxfs_typed at @indir
 122  *   and performs the type-defined action.
 123  *
 124  * Return Value:
 125  *   The physical block number on success, else Zero.
 126  *
 127  * Note:
 128  *   Kernelstack is rare.  Unrecurse?
 129  */
 130 static daddr_t
 131 vxfs_bmap_indir(struct inode *ip, long indir, int size, long block)
 132 {
 133         struct vxfs_sb_info             *sbi = VXFS_SBI(ip->i_sb);
 134         struct buffer_head              *bp = NULL;
 135         daddr_t                         pblock = 0;
 136         int                             i;
 137
 138         for (i = 0; i < size * VXFS_TYPED_PER_BLOCK(ip->i_sb); i++) {
 139                 struct vxfs_typed       *typ;
 140                 int64_t                 off;
 141
 142                 bp = sb_bread(ip->i_sb,
 143                                 indir + (i / VXFS_TYPED_PER_BLOCK(ip->i_sb)));
 144                 if (!bp || !buffer_mapped(bp))
 145                         return 0;
 146
 147                 typ = ((struct vxfs_typed *)bp->b_data) +
 148                         (i % VXFS_TYPED_PER_BLOCK(ip->i_sb));
 149                 off = fs64_to_cpu(sbi, typ->vt_hdr) & VXFS_TYPED_OFFSETMASK;
 150
 151                 if (block < off) {
 152                         brelse(bp);
 153                         continue;
 154                 }
 155
 156                 switch ((u_int32_t)(fs64_to_cpu(sbi, typ->vt_hdr) >>
 157                                 VXFS_TYPED_TYPESHIFT)) {
 158                 case VXFS_TYPED_INDIRECT:
 159                         pblock = vxfs_bmap_indir(ip,
 160                                         fs32_to_cpu(sbi, typ->vt_block),
 161                                         fs32_to_cpu(sbi, typ->vt_size),
 162                                         block - off);
 163                         if (pblock == -2)
 164                                 break;
 165                         goto out;
 166                 case VXFS_TYPED_DATA:
 167                         if ((block - off) >= fs32_to_cpu(sbi, typ->vt_size))
 168                                 break;
 169                         pblock = fs32_to_cpu(sbi, typ->vt_block) + block - off;
 170                         goto out;
 171                 case VXFS_TYPED_INDIRECT_DEV4:
 172                 case VXFS_TYPED_DATA_DEV4: {
 173                         struct vxfs_typed_dev4  *typ4 =
 174                                 (struct vxfs_typed_dev4 *)typ;
 175
 176                         printk(KERN_INFO "\n\nTYPED_DEV4 detected!\n");
 177                         printk(KERN_INFO "block: %llu\tsize: %lld\tdev: %d\n",
 178                                fs64_to_cpu(sbi, typ4->vd4_block),
 179                                fs64_to_cpu(sbi, typ4->vd4_size),
 180                                fs32_to_cpu(sbi, typ4->vd4_dev));
 181                         goto fail;
 182                 }
 183                 default:
 184                         printk(KERN_ERR "%s:%d vt_hdr %llu\n", __func__,
 185                                 __LINE__, fs64_to_cpu(sbi, typ->vt_hdr));
 186                         BUG();
 187                 }
 188                 brelse(bp);
 189         }
 190
 191 fail:
 192         pblock = 0;
 193 out:
 194         brelse(bp);
 195         return (pblock);
 196 }
 197
 198 /**
 199  * vxfs_bmap_typed - bmap for typed extents
 200  * @ip:         pointer to the inode we do bmap for
 201  * @iblock:     logical block
 202  *
 203  * Description:
 204  *   Performs the bmap operation for typed extents.
 205  *
 206  * Return Value:
 207  *   The physical block number on success, else Zero.
 208  */
 209 static daddr_t
 210 vxfs_bmap_typed(struct inode *ip, long iblock)
 211 {
 212         struct vxfs_inode_info          *vip = VXFS_INO(ip);
 213         struct vxfs_sb_info             *sbi = VXFS_SBI(ip->i_sb);
 214         daddr_t                         pblock = 0;
 215         int                             i;
 216
 217         for (i = 0; i < VXFS_NTYPED; i++) {
 218                 struct vxfs_typed       *typ = vip->vii_org.typed + i;
 219                 u64                     hdr = fs64_to_cpu(sbi, typ->vt_hdr);
 220                 int64_t                 off = (hdr & VXFS_TYPED_OFFSETMASK);
 221
 222 #ifdef DIAGNOSTIC
 223                 vxfs_typdump(typ);
 224 #endif
 225                 if (iblock < off)
 226                         continue;
 227                 switch ((u32)(hdr >> VXFS_TYPED_TYPESHIFT)) {
 228                 case VXFS_TYPED_INDIRECT:
 229                         pblock = vxfs_bmap_indir(ip,
 230                                         fs32_to_cpu(sbi, typ->vt_block),
 231                                         fs32_to_cpu(sbi, typ->vt_size),
 232                                         iblock - off);
 233                         if (pblock == -2)
 234                                 break;
 235                         return (pblock);
 236                 case VXFS_TYPED_DATA:
 237                         if ((iblock - off) < fs32_to_cpu(sbi, typ->vt_size))
 238                                 return (fs32_to_cpu(sbi, typ->vt_block) +
 239                                                 iblock - off);
 240                         break;
 241                 case VXFS_TYPED_INDIRECT_DEV4:
 242                 case VXFS_TYPED_DATA_DEV4: {
 243                         struct vxfs_typed_dev4  *typ4 =
 244                                 (struct vxfs_typed_dev4 *)typ;
 245
 246                         printk(KERN_INFO "\n\nTYPED_DEV4 detected!\n");
 247                         printk(KERN_INFO "block: %llu\tsize: %lld\tdev: %d\n",
 248                                fs64_to_cpu(sbi, typ4->vd4_block),
 249                                fs64_to_cpu(sbi, typ4->vd4_size),
 250                                fs32_to_cpu(sbi, typ4->vd4_dev));
 251                         return 0;
 252                 }
 253                 default:
 254                         BUG();
 255                 }
 256         }
 257
 258         return 0;
 259 }
 260
 261 /**
 262  * vxfs_bmap1 - vxfs-internal bmap operation
 263  * @ip:                 pointer to the inode we do bmap for
 264  * @iblock:             logical block
 265  *
 266  * Description:
 267  *   vxfs_bmap1 perfoms a logical to physical block mapping
 268  *   for vxfs-internal purposes.
 269  *
 270  * Return Value:
 271  *   The physical block number on success, else Zero.
 272  */
 273 daddr_t
 274 vxfs_bmap1(struct inode *ip, long iblock)
 275 {
 276         struct vxfs_inode_info          *vip = VXFS_INO(ip);
 277
 278         if (VXFS_ISEXT4(vip))
 279                 return vxfs_bmap_ext4(ip, iblock);
 280         if (VXFS_ISTYPED(vip))
 281                 return vxfs_bmap_typed(ip, iblock);
 282         if (VXFS_ISNONE(vip))
 283                 goto unsupp;
 284         if (VXFS_ISIMMED(vip))
 285                 goto unsupp;
 286
 287         printk(KERN_WARNING "vxfs: inode %ld has no valid orgtype (%x)\n",
 288                         ip->i_ino, vip->vii_orgtype);
 289         BUG();
 290
 291 unsupp:
 292         printk(KERN_WARNING "vxfs: inode %ld has an unsupported orgtype (%x)\n",
 293                         ip->i_ino, vip->vii_orgtype);
 294         return 0;
 295 }