release/src-rt-6.x.4708/linux/linux-2.6.36/fs/adfs/dir_fplus.c

   1 /*
   2  *  linux/fs/adfs/dir_fplus.c
   3  *
   4  *  Copyright (C) 1997-1999 Russell King
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10 #include <linux/buffer_head.h>
  11 #include "adfs.h"
  12 #include "dir_fplus.h"
  13
  14 static int
  15 adfs_fplus_read(struct super_block *sb, unsigned int id, unsigned int sz, struct adfs_dir *dir)
  16 {
  17         struct adfs_bigdirheader *h;
  18         struct adfs_bigdirtail *t;
  19         unsigned long block;
  20         unsigned int blk, size;
  21         int i, ret = -EIO;
  22
  23         dir->nr_buffers = 0;
  24
  25         block = __adfs_block_map(sb, id, 0);
  26         if (!block) {
  27                 adfs_error(sb, "dir object %X has a hole at offset 0", id);
  28                 goto out;
  29         }
  30
  31         dir->bh[0] = sb_bread(sb, block);
  32         if (!dir->bh[0])
  33                 goto out;
  34         dir->nr_buffers += 1;
  35
  36         h = (struct adfs_bigdirheader *)dir->bh[0]->b_data;
  37         size = le32_to_cpu(h->bigdirsize);
  38         if (size != sz) {
  39                 printk(KERN_WARNING "adfs: adfs_fplus_read: directory header size\n"
  40                                 " does not match directory size\n");
  41         }
  42
  43         if (h->bigdirversion[0] != 0 || h->bigdirversion[1] != 0 ||
  44             h->bigdirversion[2] != 0 || size & 2047 ||
  45             h->bigdirstartname != cpu_to_le32(BIGDIRSTARTNAME))
  46                 goto out;
  47
  48         size >>= sb->s_blocksize_bits;
  49         for (blk = 1; blk < size; blk++) {
  50                 block = __adfs_block_map(sb, id, blk);
  51                 if (!block) {
  52                         adfs_error(sb, "dir object %X has a hole at offset %d", id, blk);
  53                         goto out;
  54                 }
  55
  56                 dir->bh[blk] = sb_bread(sb, block);
  57                 if (!dir->bh[blk])
  58                         goto out;
  59                 dir->nr_buffers = blk;
  60         }
  61
  62         t = (struct adfs_bigdirtail *)(dir->bh[size - 1]->b_data + (sb->s_blocksize - 8));
  63
  64         if (t->bigdirendname != cpu_to_le32(BIGDIRENDNAME) ||
  65             t->bigdirendmasseq != h->startmasseq ||
  66             t->reserved[0] != 0 || t->reserved[1] != 0)
  67                 goto out;
  68
  69         dir->parent_id = le32_to_cpu(h->bigdirparent);
  70         dir->sb = sb;
  71         return 0;
  72 out:
  73         for (i = 0; i < dir->nr_buffers; i++)
  74                 brelse(dir->bh[i]);
  75         dir->sb = NULL;
  76         return ret;
  77 }
  78
  79 static int
  80 adfs_fplus_setpos(struct adfs_dir *dir, unsigned int fpos)
  81 {
  82         struct adfs_bigdirheader *h = (struct adfs_bigdirheader *)dir->bh[0]->b_data;
  83         int ret = -ENOENT;
  84
  85         if (fpos <= le32_to_cpu(h->bigdirentries)) {
  86                 dir->pos = fpos;
  87                 ret = 0;
  88         }
  89
  90         return ret;
  91 }
  92
  93 static void
  94 dir_memcpy(struct adfs_dir *dir, unsigned int offset, void *to, int len)
  95 {
  96         struct super_block *sb = dir->sb;
  97         unsigned int buffer, partial, remainder;
  98
  99         buffer = offset >> sb->s_blocksize_bits;
 100         offset &= sb->s_blocksize - 1;
 101
 102         partial = sb->s_blocksize - offset;
 103
 104         if (partial >= len)
 105                 memcpy(to, dir->bh[buffer]->b_data + offset, len);
 106         else {
 107                 char *c = (char *)to;
 108
 109                 remainder = len - partial;
 110
 111                 memcpy(c, dir->bh[buffer]->b_data + offset, partial);
 112                 memcpy(c + partial, dir->bh[buffer + 1]->b_data, remainder);
 113         }
 114 }
 115
 116 static int
 117 adfs_fplus_getnext(struct adfs_dir *dir, struct object_info *obj)
 118 {
 119         struct adfs_bigdirheader *h = (struct adfs_bigdirheader *)dir->bh[0]->b_data;
 120         struct adfs_bigdirentry bde;
 121         unsigned int offset;
 122         int i, ret = -ENOENT;
 123
 124         if (dir->pos >= le32_to_cpu(h->bigdirentries))
 125                 goto out;
 126
 127         offset = offsetof(struct adfs_bigdirheader, bigdirname);
 128         offset += ((le32_to_cpu(h->bigdirnamelen) + 4) & ~3);
 129         offset += dir->pos * sizeof(struct adfs_bigdirentry);
 130
 131         dir_memcpy(dir, offset, &bde, sizeof(struct adfs_bigdirentry));
 132
 133         obj->loadaddr = le32_to_cpu(bde.bigdirload);
 134         obj->execaddr = le32_to_cpu(bde.bigdirexec);
 135         obj->size     = le32_to_cpu(bde.bigdirlen);
 136         obj->file_id  = le32_to_cpu(bde.bigdirindaddr);
 137         obj->attr     = le32_to_cpu(bde.bigdirattr);
 138         obj->name_len = le32_to_cpu(bde.bigdirobnamelen);
 139
 140         offset = offsetof(struct adfs_bigdirheader, bigdirname);
 141         offset += ((le32_to_cpu(h->bigdirnamelen) + 4) & ~3);
 142         offset += le32_to_cpu(h->bigdirentries) * sizeof(struct adfs_bigdirentry);
 143         offset += le32_to_cpu(bde.bigdirobnameptr);
 144
 145         dir_memcpy(dir, offset, obj->name, obj->name_len);
 146         for (i = 0; i < obj->name_len; i++)
 147                 if (obj->name[i] == '/')
 148                         obj->name[i] = '.';
 149
 150         dir->pos += 1;
 151         ret = 0;
 152 out:
 153         return ret;
 154 }
 155
 156 static int
 157 adfs_fplus_sync(struct adfs_dir *dir)
 158 {
 159         int err = 0;
 160         int i;
 161
 162         for (i = dir->nr_buffers - 1; i >= 0; i--) {
 163                 struct buffer_head *bh = dir->bh[i];
 164                 sync_dirty_buffer(bh);
 165                 if (buffer_req(bh) && !buffer_uptodate(bh))
 166                         err = -EIO;
 167         }
 168
 169         return err;
 170 }
 171
 172 static void
 173 adfs_fplus_free(struct adfs_dir *dir)
 174 {
 175         int i;
 176
 177         for (i = 0; i < dir->nr_buffers; i++)
 178                 brelse(dir->bh[i]);
 179         dir->sb = NULL;
 180 }
 181
 182 struct adfs_dir_ops adfs_fplus_dir_ops = {
 183         .read           = adfs_fplus_read,
 184         .setpos         = adfs_fplus_setpos,
 185         .getnext        = adfs_fplus_getnext,
 186         .sync           = adfs_fplus_sync,
 187         .free           = adfs_fplus_free
 188 };