1 /* 2 * fs/bfs/dir.c 3 * BFS directory operations. 4 * Copyright (C) 1999,2000 Tigran Aivazian <tigran@veritas.com> 5 * Made endianness-clean by Andrew Stribblehill <ads@wompom.org> 2005 6 */ 7 8 #include <linux/time.h> 9 #include <linux/string.h> 10 #include <linux/fs.h> 11 #include <linux/buffer_head.h> 12 #include <linux/sched.h> 13 #include "bfs.h" 14 15 #undef DEBUG 16 17 #ifdef DEBUG 18 #define dprintf(x...) printf(x) 19 #else 20 #define dprintf(x...) 21 #endif 22 23 static int bfs_add_entry(struct inode *dir, const unsigned char *name, 24 int namelen, int ino); 25 static struct buffer_head *bfs_find_entry(struct inode *dir, 26 const unsigned char *name, int namelen, 27 struct bfs_dirent **res_dir); 28 29 static int bfs_readdir(struct file *f, void *dirent, filldir_t filldir) 30 { 31 struct inode *dir = f->f_path.dentry->d_inode; 32 struct buffer_head *bh; 33 struct bfs_dirent *de; 34 struct bfs_sb_info *info = BFS_SB(dir->i_sb); 35 unsigned int offset; 36 int block; 37 38 mutex_lock(&info->bfs_lock); 39 40 if (f->f_pos & (BFS_DIRENT_SIZE - 1)) { 41 printf("Bad f_pos=%08lx for %s:%08lx\n", 42 (unsigned long)f->f_pos, 43 dir->i_sb->s_id, dir->i_ino); 44 mutex_unlock(&info->bfs_lock); 45 return -EBADF; 46 } 47 48 while (f->f_pos < dir->i_size) { 49 offset = f->f_pos & (BFS_BSIZE - 1); 50 block = BFS_I(dir)->i_sblock + (f->f_pos >> BFS_BSIZE_BITS); 51 bh = sb_bread(dir->i_sb, block); 52 if (!bh) { 53 f->f_pos += BFS_BSIZE - offset; 54 continue; 55 } 56 do { 57 de = (struct bfs_dirent *)(bh->b_data + offset); 58 if (de->ino) { 59 int size = strnlen(de->name, BFS_NAMELEN); 60 if (filldir(dirent, de->name, size, f->f_pos, 61 le16_to_cpu(de->ino), 62 DT_UNKNOWN) < 0) { 63 brelse(bh); 64 mutex_unlock(&info->bfs_lock); 65 return 0; 66 } 67 } 68 offset += BFS_DIRENT_SIZE; 69 f->f_pos += BFS_DIRENT_SIZE; 70 } while ((offset < BFS_BSIZE) && (f->f_pos < dir->i_size)); 71 brelse(bh); 72 } 73 74 mutex_unlock(&info->bfs_lock); 75 return 0; 76 } 77 78 const struct file_operations bfs_dir_operations = { 79 .read = generic_read_dir, 80 .readdir = bfs_readdir, 81 .fsync = simple_fsync, 82 .llseek = generic_file_llseek, 83 }; 84 85 extern void dump_imap(const char *, struct super_block *); 86 87 static int bfs_create(struct inode *dir, struct dentry *dentry, int mode, 88 struct nameidata *nd) 89 { 90 int err; 91 struct inode *inode; 92 struct super_block *s = dir->i_sb; 93 struct bfs_sb_info *info = BFS_SB(s); 94 unsigned long ino; 95 96 inode = new_inode(s); 97 if (!inode) 98 return -ENOSPC; 99 mutex_lock(&info->bfs_lock); 100 ino = find_first_zero_bit(info->si_imap, info->si_lasti); 101 if (ino > info->si_lasti) { 102 mutex_unlock(&info->bfs_lock); 103 iput(inode); 104 return -ENOSPC; 105 } 106 set_bit(ino, info->si_imap); 107 info->si_freei--; 108 inode->i_uid = current_fsuid(); 109 inode->i_gid = (dir->i_mode & S_ISGID) ? dir->i_gid : current_fsgid(); 110 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC; 111 inode->i_blocks = 0; 112 inode->i_op = &bfs_file_inops; 113 inode->i_fop = &bfs_file_operations; 114 inode->i_mapping->a_ops = &bfs_aops; 115 inode->i_mode = mode; 116 inode->i_ino = ino; 117 BFS_I(inode)->i_dsk_ino = ino; 118 BFS_I(inode)->i_sblock = 0; 119 BFS_I(inode)->i_eblock = 0; 120 insert_inode_hash(inode); 121 mark_inode_dirty(inode); 122 dump_imap("create", s); 123 124 err = bfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len, 125 inode->i_ino); 126 if (err) { 127 inode_dec_link_count(inode); 128 mutex_unlock(&info->bfs_lock); 129 iput(inode); 130 return err; 131 } 132 mutex_unlock(&info->bfs_lock); 133 d_instantiate(dentry, inode); 134 return 0; 135 } 136 137 static struct dentry *bfs_lookup(struct inode *dir, struct dentry *dentry, 138 struct nameidata *nd) 139 { 140 struct inode *inode = NULL; 141 struct buffer_head *bh; 142 struct bfs_dirent *de; 143 struct bfs_sb_info *info = BFS_SB(dir->i_sb); 144 145 if (dentry->d_name.len > BFS_NAMELEN) 146 return ERR_PTR(-ENAMETOOLONG); 147 148 mutex_lock(&info->bfs_lock); 149 bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de); 150 if (bh) { 151 unsigned long ino = (unsigned long)le16_to_cpu(de->ino); 152 brelse(bh); 153 inode = bfs_iget(dir->i_sb, ino); 154 if (IS_ERR(inode)) { 155 mutex_unlock(&info->bfs_lock); 156 return ERR_CAST(inode); 157 } 158 } 159 mutex_unlock(&info->bfs_lock); 160 d_add(dentry, inode); 161 return NULL; 162 } 163 164 static int bfs_link(struct dentry *old, struct inode *dir, 165 struct dentry *new) 166 { 167 struct inode *inode = old->d_inode; 168 struct bfs_sb_info *info = BFS_SB(inode->i_sb); 169 int err; 170 171 mutex_lock(&info->bfs_lock); 172 err = bfs_add_entry(dir, new->d_name.name, new->d_name.len, 173 inode->i_ino); 174 if (err) { 175 mutex_unlock(&info->bfs_lock); 176 return err; 177 } 178 inc_nlink(inode); 179 inode->i_ctime = CURRENT_TIME_SEC; 180 mark_inode_dirty(inode); 181 atomic_inc(&inode->i_count); 182 d_instantiate(new, inode); 183 mutex_unlock(&info->bfs_lock); 184 return 0; 185 } 186 187 static int bfs_unlink(struct inode *dir, struct dentry *dentry) 188 { 189 int error = -ENOENT; 190 struct inode *inode = dentry->d_inode; 191 struct buffer_head *bh; 192 struct bfs_dirent *de; 193 struct bfs_sb_info *info = BFS_SB(inode->i_sb); 194 195 mutex_lock(&info->bfs_lock); 196 bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de); 197 if (!bh || (le16_to_cpu(de->ino) != inode->i_ino)) 198 goto out_brelse; 199 200 if (!inode->i_nlink) { 201 printf("unlinking non-existent file %s:%lu (nlink=%d)\n", 202 inode->i_sb->s_id, inode->i_ino, 203 inode->i_nlink); 204 inode->i_nlink = 1; 205 } 206 de->ino = 0; 207 mark_buffer_dirty_inode(bh, dir); 208 dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC; 209 mark_inode_dirty(dir); 210 inode->i_ctime = dir->i_ctime; 211 inode_dec_link_count(inode); 212 error = 0; 213 214 out_brelse: 215 brelse(bh); 216 mutex_unlock(&info->bfs_lock); 217 return error; 218 } 219 220 static int bfs_rename(struct inode *old_dir, struct dentry *old_dentry, 221 struct inode *new_dir, struct dentry *new_dentry) 222 { 223 struct inode *old_inode, *new_inode; 224 struct buffer_head *old_bh, *new_bh; 225 struct bfs_dirent *old_de, *new_de; 226 struct bfs_sb_info *info; 227 int error = -ENOENT; 228 229 old_bh = new_bh = NULL; 230 old_inode = old_dentry->d_inode; 231 if (S_ISDIR(old_inode->i_mode)) 232 return -EINVAL; 233 234 info = BFS_SB(old_inode->i_sb); 235 236 mutex_lock(&info->bfs_lock); 237 old_bh = bfs_find_entry(old_dir, 238 old_dentry->d_name.name, 239 old_dentry->d_name.len, &old_de); 240 241 if (!old_bh || (le16_to_cpu(old_de->ino) != old_inode->i_ino)) 242 goto end_rename; 243 244 error = -EPERM; 245 new_inode = new_dentry->d_inode; 246 new_bh = bfs_find_entry(new_dir, 247 new_dentry->d_name.name, 248 new_dentry->d_name.len, &new_de); 249 250 if (new_bh && !new_inode) { 251 brelse(new_bh); 252 new_bh = NULL; 253 } 254 if (!new_bh) { 255 error = bfs_add_entry(new_dir, 256 new_dentry->d_name.name, 257 new_dentry->d_name.len, 258 old_inode->i_ino); 259 if (error) 260 goto end_rename; 261 } 262 old_de->ino = 0; 263 old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC; 264 mark_inode_dirty(old_dir); 265 if (new_inode) { 266 new_inode->i_ctime = CURRENT_TIME_SEC; 267 inode_dec_link_count(new_inode); 268 } 269 mark_buffer_dirty_inode(old_bh, old_dir); 270 error = 0; 271 272 end_rename: 273 mutex_unlock(&info->bfs_lock); 274 brelse(old_bh); 275 brelse(new_bh); 276 return error; 277 } 278 279 const struct inode_operations bfs_dir_inops = { 280 .create = bfs_create, 281 .lookup = bfs_lookup, 282 .link = bfs_link, 283 .unlink = bfs_unlink, 284 .rename = bfs_rename, 285 }; 286 287 static int bfs_add_entry(struct inode *dir, const unsigned char *name, 288 int namelen, int ino) 289 { 290 struct buffer_head *bh; 291 struct bfs_dirent *de; 292 int block, sblock, eblock, off, pos; 293 int i; 294 295 dprintf("name=%s, namelen=%d\n", name, namelen); 296 297 if (!namelen) 298 return -ENOENT; 299 if (namelen > BFS_NAMELEN) 300 return -ENAMETOOLONG; 301 302 sblock = BFS_I(dir)->i_sblock; 303 eblock = BFS_I(dir)->i_eblock; 304 for (block = sblock; block <= eblock; block++) { 305 bh = sb_bread(dir->i_sb, block); 306 if (!bh) 307 return -ENOSPC; 308 for (off = 0; off < BFS_BSIZE; off += BFS_DIRENT_SIZE) { 309 de = (struct bfs_dirent *)(bh->b_data + off); 310 if (!de->ino) { 311 pos = (block - sblock) * BFS_BSIZE + off; 312 if (pos >= dir->i_size) { 313 dir->i_size += BFS_DIRENT_SIZE; 314 dir->i_ctime = CURRENT_TIME_SEC; 315 } 316 dir->i_mtime = CURRENT_TIME_SEC; 317 mark_inode_dirty(dir); 318 de->ino = cpu_to_le16((u16)ino); 319 for (i = 0; i < BFS_NAMELEN; i++) 320 de->name[i] = 321 (i < namelen) ? name[i] : 0; 322 mark_buffer_dirty_inode(bh, dir); 323 brelse(bh); 324 return 0; 325 } 326 } 327 brelse(bh); 328 } 329 return -ENOSPC; 330 } 331 332 static inline int bfs_namecmp(int len, const unsigned char *name, 333 const char *buffer) 334 { 335 if ((len < BFS_NAMELEN) && buffer[len]) 336 return 0; 337 return !memcmp(name, buffer, len); 338 } 339 340 static struct buffer_head *bfs_find_entry(struct inode *dir, 341 const unsigned char *name, int namelen, 342 struct bfs_dirent **res_dir) 343 { 344 unsigned long block = 0, offset = 0; 345 struct buffer_head *bh = NULL; 346 struct bfs_dirent *de; 347 348 *res_dir = NULL; 349 if (namelen > BFS_NAMELEN) 350 return NULL; 351 352 while (block * BFS_BSIZE + offset < dir->i_size) { 353 if (!bh) { 354 bh = sb_bread(dir->i_sb, BFS_I(dir)->i_sblock + block); 355 if (!bh) { 356 block++; 357 continue; 358 } 359 } 360 de = (struct bfs_dirent *)(bh->b_data + offset); 361 offset += BFS_DIRENT_SIZE; 362 if (le16_to_cpu(de->ino) && 363 bfs_namecmp(namelen, name, de->name)) { 364 *res_dir = de; 365 return bh; 366 } 367 if (offset < bh->b_size) 368 continue; 369 brelse(bh); 370 bh = NULL; 371 offset = 0; 372 block++; 373 } 374 brelse(bh); 375 return NULL; 376 } 377