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