1a3ab7155SBob Copeland /* 2a3ab7155SBob Copeland * OMFS (as used by RIO Karma) directory operations. 3a3ab7155SBob Copeland * Copyright (C) 2005 Bob Copeland <me@bobcopeland.com> 4a3ab7155SBob Copeland * Released under GPL v2. 5a3ab7155SBob Copeland */ 6a3ab7155SBob Copeland 7a3ab7155SBob Copeland #include <linux/fs.h> 8a3ab7155SBob Copeland #include <linux/ctype.h> 9a3ab7155SBob Copeland #include <linux/buffer_head.h> 10a3ab7155SBob Copeland #include "omfs.h" 11a3ab7155SBob Copeland 12a3ab7155SBob Copeland static int omfs_hash(const char *name, int namelen, int mod) 13a3ab7155SBob Copeland { 14a3ab7155SBob Copeland int i, hash = 0; 15a3ab7155SBob Copeland for (i = 0; i < namelen; i++) 16a3ab7155SBob Copeland hash ^= tolower(name[i]) << (i % 24); 17a3ab7155SBob Copeland return hash % mod; 18a3ab7155SBob Copeland } 19a3ab7155SBob Copeland 20a3ab7155SBob Copeland /* 21a3ab7155SBob Copeland * Finds the bucket for a given name and reads the containing block; 22a3ab7155SBob Copeland * *ofs is set to the offset of the first list entry. 23a3ab7155SBob Copeland */ 24a3ab7155SBob Copeland static struct buffer_head *omfs_get_bucket(struct inode *dir, 25a3ab7155SBob Copeland const char *name, int namelen, int *ofs) 26a3ab7155SBob Copeland { 27a3ab7155SBob Copeland int nbuckets = (dir->i_size - OMFS_DIR_START)/8; 28a3ab7155SBob Copeland int bucket = omfs_hash(name, namelen, nbuckets); 29a3ab7155SBob Copeland 30a3ab7155SBob Copeland *ofs = OMFS_DIR_START + bucket * 8; 31f068272cSBob Copeland return omfs_bread(dir->i_sb, dir->i_ino); 32a3ab7155SBob Copeland } 33a3ab7155SBob Copeland 34a3ab7155SBob Copeland static struct buffer_head *omfs_scan_list(struct inode *dir, u64 block, 35a3ab7155SBob Copeland const char *name, int namelen, 36a3ab7155SBob Copeland u64 *prev_block) 37a3ab7155SBob Copeland { 38a3ab7155SBob Copeland struct buffer_head *bh; 39a3ab7155SBob Copeland struct omfs_inode *oi; 40a3ab7155SBob Copeland int err = -ENOENT; 41a3ab7155SBob Copeland *prev_block = ~0; 42a3ab7155SBob Copeland 43a3ab7155SBob Copeland while (block != ~0) { 44f068272cSBob Copeland bh = omfs_bread(dir->i_sb, block); 45a3ab7155SBob Copeland if (!bh) { 46a3ab7155SBob Copeland err = -EIO; 47a3ab7155SBob Copeland goto err; 48a3ab7155SBob Copeland } 49a3ab7155SBob Copeland 50a3ab7155SBob Copeland oi = (struct omfs_inode *) bh->b_data; 51a3ab7155SBob Copeland if (omfs_is_bad(OMFS_SB(dir->i_sb), &oi->i_head, block)) { 52a3ab7155SBob Copeland brelse(bh); 53a3ab7155SBob Copeland goto err; 54a3ab7155SBob Copeland } 55a3ab7155SBob Copeland 56a3ab7155SBob Copeland if (strncmp(oi->i_name, name, namelen) == 0) 57a3ab7155SBob Copeland return bh; 58a3ab7155SBob Copeland 59a3ab7155SBob Copeland *prev_block = block; 60a3ab7155SBob Copeland block = be64_to_cpu(oi->i_sibling); 61a3ab7155SBob Copeland brelse(bh); 62a3ab7155SBob Copeland } 63a3ab7155SBob Copeland err: 64a3ab7155SBob Copeland return ERR_PTR(err); 65a3ab7155SBob Copeland } 66a3ab7155SBob Copeland 67a3ab7155SBob Copeland static struct buffer_head *omfs_find_entry(struct inode *dir, 68a3ab7155SBob Copeland const char *name, int namelen) 69a3ab7155SBob Copeland { 70a3ab7155SBob Copeland struct buffer_head *bh; 71a3ab7155SBob Copeland int ofs; 72a3ab7155SBob Copeland u64 block, dummy; 73a3ab7155SBob Copeland 74a3ab7155SBob Copeland bh = omfs_get_bucket(dir, name, namelen, &ofs); 75a3ab7155SBob Copeland if (!bh) 76a3ab7155SBob Copeland return ERR_PTR(-EIO); 77a3ab7155SBob Copeland 78a3ab7155SBob Copeland block = be64_to_cpu(*((__be64 *) &bh->b_data[ofs])); 79a3ab7155SBob Copeland brelse(bh); 80a3ab7155SBob Copeland 81a3ab7155SBob Copeland return omfs_scan_list(dir, block, name, namelen, &dummy); 82a3ab7155SBob Copeland } 83a3ab7155SBob Copeland 84a3ab7155SBob Copeland int omfs_make_empty(struct inode *inode, struct super_block *sb) 85a3ab7155SBob Copeland { 86a3ab7155SBob Copeland struct omfs_sb_info *sbi = OMFS_SB(sb); 87a3ab7155SBob Copeland struct buffer_head *bh; 88a3ab7155SBob Copeland struct omfs_inode *oi; 89a3ab7155SBob Copeland 90f068272cSBob Copeland bh = omfs_bread(sb, inode->i_ino); 91a3ab7155SBob Copeland if (!bh) 92a3ab7155SBob Copeland return -ENOMEM; 93a3ab7155SBob Copeland 94a3ab7155SBob Copeland memset(bh->b_data, 0, sizeof(struct omfs_inode)); 95a3ab7155SBob Copeland 96a3ab7155SBob Copeland if (inode->i_mode & S_IFDIR) { 97a3ab7155SBob Copeland memset(&bh->b_data[OMFS_DIR_START], 0xff, 98a3ab7155SBob Copeland sbi->s_sys_blocksize - OMFS_DIR_START); 99a3ab7155SBob Copeland } else 100a3ab7155SBob Copeland omfs_make_empty_table(bh, OMFS_EXTENT_START); 101a3ab7155SBob Copeland 102a3ab7155SBob Copeland oi = (struct omfs_inode *) bh->b_data; 103a3ab7155SBob Copeland oi->i_head.h_self = cpu_to_be64(inode->i_ino); 104d406f66dSHarvey Harrison oi->i_sibling = ~cpu_to_be64(0ULL); 105a3ab7155SBob Copeland 106a3ab7155SBob Copeland mark_buffer_dirty(bh); 107a3ab7155SBob Copeland brelse(bh); 108a3ab7155SBob Copeland return 0; 109a3ab7155SBob Copeland } 110a3ab7155SBob Copeland 111a3ab7155SBob Copeland static int omfs_add_link(struct dentry *dentry, struct inode *inode) 112a3ab7155SBob Copeland { 113a3ab7155SBob Copeland struct inode *dir = dentry->d_parent->d_inode; 114a3ab7155SBob Copeland const char *name = dentry->d_name.name; 115a3ab7155SBob Copeland int namelen = dentry->d_name.len; 116a3ab7155SBob Copeland struct omfs_inode *oi; 117a3ab7155SBob Copeland struct buffer_head *bh; 118a3ab7155SBob Copeland u64 block; 119a3ab7155SBob Copeland __be64 *entry; 120a3ab7155SBob Copeland int ofs; 121a3ab7155SBob Copeland 122a3ab7155SBob Copeland /* just prepend to head of queue in proper bucket */ 123a3ab7155SBob Copeland bh = omfs_get_bucket(dir, name, namelen, &ofs); 124a3ab7155SBob Copeland if (!bh) 125a3ab7155SBob Copeland goto out; 126a3ab7155SBob Copeland 127a3ab7155SBob Copeland entry = (__be64 *) &bh->b_data[ofs]; 128a3ab7155SBob Copeland block = be64_to_cpu(*entry); 129a3ab7155SBob Copeland *entry = cpu_to_be64(inode->i_ino); 130a3ab7155SBob Copeland mark_buffer_dirty(bh); 131a3ab7155SBob Copeland brelse(bh); 132a3ab7155SBob Copeland 133a3ab7155SBob Copeland /* now set the sibling and parent pointers on the new inode */ 134f068272cSBob Copeland bh = omfs_bread(dir->i_sb, inode->i_ino); 135a3ab7155SBob Copeland if (!bh) 136a3ab7155SBob Copeland goto out; 137a3ab7155SBob Copeland 138a3ab7155SBob Copeland oi = (struct omfs_inode *) bh->b_data; 139a3ab7155SBob Copeland memcpy(oi->i_name, name, namelen); 140a3ab7155SBob Copeland memset(oi->i_name + namelen, 0, OMFS_NAMELEN - namelen); 141a3ab7155SBob Copeland oi->i_sibling = cpu_to_be64(block); 142a3ab7155SBob Copeland oi->i_parent = cpu_to_be64(dir->i_ino); 143a3ab7155SBob Copeland mark_buffer_dirty(bh); 144a3ab7155SBob Copeland brelse(bh); 145a3ab7155SBob Copeland 146a3ab7155SBob Copeland dir->i_ctime = CURRENT_TIME_SEC; 147a3ab7155SBob Copeland 148a3ab7155SBob Copeland /* mark affected inodes dirty to rebuild checksums */ 149a3ab7155SBob Copeland mark_inode_dirty(dir); 150a3ab7155SBob Copeland mark_inode_dirty(inode); 151a3ab7155SBob Copeland return 0; 152a3ab7155SBob Copeland out: 153a3ab7155SBob Copeland return -ENOMEM; 154a3ab7155SBob Copeland } 155a3ab7155SBob Copeland 156a3ab7155SBob Copeland static int omfs_delete_entry(struct dentry *dentry) 157a3ab7155SBob Copeland { 158a3ab7155SBob Copeland struct inode *dir = dentry->d_parent->d_inode; 159a3ab7155SBob Copeland struct inode *dirty; 160a3ab7155SBob Copeland const char *name = dentry->d_name.name; 161a3ab7155SBob Copeland int namelen = dentry->d_name.len; 162a3ab7155SBob Copeland struct omfs_inode *oi; 163a3ab7155SBob Copeland struct buffer_head *bh, *bh2; 164a3ab7155SBob Copeland __be64 *entry, next; 165a3ab7155SBob Copeland u64 block, prev; 166a3ab7155SBob Copeland int ofs; 167a3ab7155SBob Copeland int err = -ENOMEM; 168a3ab7155SBob Copeland 169a3ab7155SBob Copeland /* delete the proper node in the bucket's linked list */ 170a3ab7155SBob Copeland bh = omfs_get_bucket(dir, name, namelen, &ofs); 171a3ab7155SBob Copeland if (!bh) 172a3ab7155SBob Copeland goto out; 173a3ab7155SBob Copeland 174a3ab7155SBob Copeland entry = (__be64 *) &bh->b_data[ofs]; 175a3ab7155SBob Copeland block = be64_to_cpu(*entry); 176a3ab7155SBob Copeland 177a3ab7155SBob Copeland bh2 = omfs_scan_list(dir, block, name, namelen, &prev); 178a3ab7155SBob Copeland if (IS_ERR(bh2)) { 179a3ab7155SBob Copeland err = PTR_ERR(bh2); 180a3ab7155SBob Copeland goto out_free_bh; 181a3ab7155SBob Copeland } 182a3ab7155SBob Copeland 183a3ab7155SBob Copeland oi = (struct omfs_inode *) bh2->b_data; 184a3ab7155SBob Copeland next = oi->i_sibling; 185a3ab7155SBob Copeland brelse(bh2); 186a3ab7155SBob Copeland 187a3ab7155SBob Copeland if (prev != ~0) { 188a3ab7155SBob Copeland /* found in middle of list, get list ptr */ 189a3ab7155SBob Copeland brelse(bh); 190f068272cSBob Copeland bh = omfs_bread(dir->i_sb, prev); 191a3ab7155SBob Copeland if (!bh) 192a3ab7155SBob Copeland goto out; 193a3ab7155SBob Copeland 194a3ab7155SBob Copeland oi = (struct omfs_inode *) bh->b_data; 195a3ab7155SBob Copeland entry = &oi->i_sibling; 196a3ab7155SBob Copeland } 197a3ab7155SBob Copeland 198a3ab7155SBob Copeland *entry = next; 199a3ab7155SBob Copeland mark_buffer_dirty(bh); 200a3ab7155SBob Copeland 201a3ab7155SBob Copeland if (prev != ~0) { 202a3ab7155SBob Copeland dirty = omfs_iget(dir->i_sb, prev); 203a3ab7155SBob Copeland if (!IS_ERR(dirty)) { 204a3ab7155SBob Copeland mark_inode_dirty(dirty); 205a3ab7155SBob Copeland iput(dirty); 206a3ab7155SBob Copeland } 207a3ab7155SBob Copeland } 208a3ab7155SBob Copeland 209a3ab7155SBob Copeland err = 0; 210a3ab7155SBob Copeland out_free_bh: 211a3ab7155SBob Copeland brelse(bh); 212a3ab7155SBob Copeland out: 213a3ab7155SBob Copeland return err; 214a3ab7155SBob Copeland } 215a3ab7155SBob Copeland 216a3ab7155SBob Copeland static int omfs_dir_is_empty(struct inode *inode) 217a3ab7155SBob Copeland { 218a3ab7155SBob Copeland int nbuckets = (inode->i_size - OMFS_DIR_START) / 8; 219a3ab7155SBob Copeland struct buffer_head *bh; 220a3ab7155SBob Copeland u64 *ptr; 221a3ab7155SBob Copeland int i; 222a3ab7155SBob Copeland 223f068272cSBob Copeland bh = omfs_bread(inode->i_sb, inode->i_ino); 224a3ab7155SBob Copeland 225a3ab7155SBob Copeland if (!bh) 226a3ab7155SBob Copeland return 0; 227a3ab7155SBob Copeland 228a3ab7155SBob Copeland ptr = (u64 *) &bh->b_data[OMFS_DIR_START]; 229a3ab7155SBob Copeland 230a3ab7155SBob Copeland for (i = 0; i < nbuckets; i++, ptr++) 231a3ab7155SBob Copeland if (*ptr != ~0) 232a3ab7155SBob Copeland break; 233a3ab7155SBob Copeland 234a3ab7155SBob Copeland brelse(bh); 235a3ab7155SBob Copeland return *ptr != ~0; 236a3ab7155SBob Copeland } 237a3ab7155SBob Copeland 238d932805bSAl Viro static int omfs_remove(struct inode *dir, struct dentry *dentry) 239a3ab7155SBob Copeland { 240a3ab7155SBob Copeland struct inode *inode = dentry->d_inode; 241d932805bSAl Viro int ret; 242d932805bSAl Viro 243d932805bSAl Viro if (S_ISDIR(inode->i_mode) && !omfs_dir_is_empty(inode)) 244d932805bSAl Viro return -ENOTEMPTY; 245a3ab7155SBob Copeland 246a3ab7155SBob Copeland ret = omfs_delete_entry(dentry); 247a3ab7155SBob Copeland if (ret) 248a3ab7155SBob Copeland return ret; 249a3ab7155SBob Copeland 250d932805bSAl Viro clear_nlink(inode); 251d932805bSAl Viro mark_inode_dirty(inode); 252d932805bSAl Viro mark_inode_dirty(dir); 253d932805bSAl Viro return 0; 254a3ab7155SBob Copeland } 255a3ab7155SBob Copeland 256a3ab7155SBob Copeland static int omfs_add_node(struct inode *dir, struct dentry *dentry, int mode) 257a3ab7155SBob Copeland { 258a3ab7155SBob Copeland int err; 259a3ab7155SBob Copeland struct inode *inode = omfs_new_inode(dir, mode); 260a3ab7155SBob Copeland 261a3ab7155SBob Copeland if (IS_ERR(inode)) 262a3ab7155SBob Copeland return PTR_ERR(inode); 263a3ab7155SBob Copeland 264a3ab7155SBob Copeland err = omfs_make_empty(inode, dir->i_sb); 265a3ab7155SBob Copeland if (err) 266a3ab7155SBob Copeland goto out_free_inode; 267a3ab7155SBob Copeland 268a3ab7155SBob Copeland err = omfs_add_link(dentry, inode); 269a3ab7155SBob Copeland if (err) 270a3ab7155SBob Copeland goto out_free_inode; 271a3ab7155SBob Copeland 272a3ab7155SBob Copeland d_instantiate(dentry, inode); 273a3ab7155SBob Copeland return 0; 274a3ab7155SBob Copeland 275a3ab7155SBob Copeland out_free_inode: 276a3ab7155SBob Copeland iput(inode); 277a3ab7155SBob Copeland return err; 278a3ab7155SBob Copeland } 279a3ab7155SBob Copeland 280a3ab7155SBob Copeland static int omfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) 281a3ab7155SBob Copeland { 282a3ab7155SBob Copeland return omfs_add_node(dir, dentry, mode | S_IFDIR); 283a3ab7155SBob Copeland } 284a3ab7155SBob Copeland 285a3ab7155SBob Copeland static int omfs_create(struct inode *dir, struct dentry *dentry, int mode, 286a3ab7155SBob Copeland struct nameidata *nd) 287a3ab7155SBob Copeland { 288a3ab7155SBob Copeland return omfs_add_node(dir, dentry, mode | S_IFREG); 289a3ab7155SBob Copeland } 290a3ab7155SBob Copeland 291a3ab7155SBob Copeland static struct dentry *omfs_lookup(struct inode *dir, struct dentry *dentry, 292a3ab7155SBob Copeland struct nameidata *nd) 293a3ab7155SBob Copeland { 294a3ab7155SBob Copeland struct buffer_head *bh; 295a3ab7155SBob Copeland struct inode *inode = NULL; 296a3ab7155SBob Copeland 297a3ab7155SBob Copeland if (dentry->d_name.len > OMFS_NAMELEN) 298a3ab7155SBob Copeland return ERR_PTR(-ENAMETOOLONG); 299a3ab7155SBob Copeland 300a3ab7155SBob Copeland bh = omfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len); 301a3ab7155SBob Copeland if (!IS_ERR(bh)) { 302a3ab7155SBob Copeland struct omfs_inode *oi = (struct omfs_inode *)bh->b_data; 303a3ab7155SBob Copeland ino_t ino = be64_to_cpu(oi->i_head.h_self); 304a3ab7155SBob Copeland brelse(bh); 305a3ab7155SBob Copeland inode = omfs_iget(dir->i_sb, ino); 306a3ab7155SBob Copeland if (IS_ERR(inode)) 307a3ab7155SBob Copeland return ERR_CAST(inode); 308a3ab7155SBob Copeland } 309a3ab7155SBob Copeland d_add(dentry, inode); 310a3ab7155SBob Copeland return NULL; 311a3ab7155SBob Copeland } 312a3ab7155SBob Copeland 313a3ab7155SBob Copeland /* sanity check block's self pointer */ 314a3ab7155SBob Copeland int omfs_is_bad(struct omfs_sb_info *sbi, struct omfs_header *header, 315a3ab7155SBob Copeland u64 fsblock) 316a3ab7155SBob Copeland { 317a3ab7155SBob Copeland int is_bad; 318a3ab7155SBob Copeland u64 ino = be64_to_cpu(header->h_self); 319a3ab7155SBob Copeland is_bad = ((ino != fsblock) || (ino < sbi->s_root_ino) || 320a3ab7155SBob Copeland (ino > sbi->s_num_blocks)); 321a3ab7155SBob Copeland 322a3ab7155SBob Copeland if (is_bad) 323a3ab7155SBob Copeland printk(KERN_WARNING "omfs: bad hash chain detected\n"); 324a3ab7155SBob Copeland 325a3ab7155SBob Copeland return is_bad; 326a3ab7155SBob Copeland } 327a3ab7155SBob Copeland 328a3ab7155SBob Copeland static int omfs_fill_chain(struct file *filp, void *dirent, filldir_t filldir, 329a3ab7155SBob Copeland u64 fsblock, int hindex) 330a3ab7155SBob Copeland { 331a3ab7155SBob Copeland struct inode *dir = filp->f_dentry->d_inode; 332a3ab7155SBob Copeland struct buffer_head *bh; 333a3ab7155SBob Copeland struct omfs_inode *oi; 334a3ab7155SBob Copeland u64 self; 335a3ab7155SBob Copeland int res = 0; 336a3ab7155SBob Copeland unsigned char d_type; 337a3ab7155SBob Copeland 338a3ab7155SBob Copeland /* follow chain in this bucket */ 339a3ab7155SBob Copeland while (fsblock != ~0) { 340f068272cSBob Copeland bh = omfs_bread(dir->i_sb, fsblock); 341a3ab7155SBob Copeland if (!bh) 342a3ab7155SBob Copeland goto out; 343a3ab7155SBob Copeland 344a3ab7155SBob Copeland oi = (struct omfs_inode *) bh->b_data; 345a3ab7155SBob Copeland if (omfs_is_bad(OMFS_SB(dir->i_sb), &oi->i_head, fsblock)) { 346a3ab7155SBob Copeland brelse(bh); 347a3ab7155SBob Copeland goto out; 348a3ab7155SBob Copeland } 349a3ab7155SBob Copeland 350a3ab7155SBob Copeland self = fsblock; 351a3ab7155SBob Copeland fsblock = be64_to_cpu(oi->i_sibling); 352a3ab7155SBob Copeland 353a3ab7155SBob Copeland /* skip visited nodes */ 354a3ab7155SBob Copeland if (hindex) { 355a3ab7155SBob Copeland hindex--; 356a3ab7155SBob Copeland brelse(bh); 357a3ab7155SBob Copeland continue; 358a3ab7155SBob Copeland } 359a3ab7155SBob Copeland 360a3ab7155SBob Copeland d_type = (oi->i_type == OMFS_DIR) ? DT_DIR : DT_REG; 361a3ab7155SBob Copeland 362a3ab7155SBob Copeland res = filldir(dirent, oi->i_name, strnlen(oi->i_name, 363a3ab7155SBob Copeland OMFS_NAMELEN), filp->f_pos, self, d_type); 364a3ab7155SBob Copeland if (res == 0) 365a3ab7155SBob Copeland filp->f_pos++; 366a3ab7155SBob Copeland brelse(bh); 367a3ab7155SBob Copeland } 368a3ab7155SBob Copeland out: 369a3ab7155SBob Copeland return res; 370a3ab7155SBob Copeland } 371a3ab7155SBob Copeland 372a3ab7155SBob Copeland static int omfs_rename(struct inode *old_dir, struct dentry *old_dentry, 373a3ab7155SBob Copeland struct inode *new_dir, struct dentry *new_dentry) 374a3ab7155SBob Copeland { 375a3ab7155SBob Copeland struct inode *new_inode = new_dentry->d_inode; 376a3ab7155SBob Copeland struct inode *old_inode = old_dentry->d_inode; 377a3ab7155SBob Copeland int err; 378a3ab7155SBob Copeland 379a3ab7155SBob Copeland if (new_inode) { 380a3ab7155SBob Copeland /* overwriting existing file/dir */ 381d932805bSAl Viro err = omfs_remove(new_dir, new_dentry); 382a3ab7155SBob Copeland if (err) 383a3ab7155SBob Copeland goto out; 384a3ab7155SBob Copeland } 385a3ab7155SBob Copeland 386a3ab7155SBob Copeland /* since omfs locates files by name, we need to unlink _before_ 387a3ab7155SBob Copeland * adding the new link or we won't find the old one */ 388cdb26496SAl Viro err = omfs_delete_entry(old_dentry); 389cdb26496SAl Viro if (err) 390a3ab7155SBob Copeland goto out; 391a3ab7155SBob Copeland 392cdb26496SAl Viro mark_inode_dirty(old_dir); 393a3ab7155SBob Copeland err = omfs_add_link(new_dentry, old_inode); 394a3ab7155SBob Copeland if (err) 395a3ab7155SBob Copeland goto out; 396a3ab7155SBob Copeland 397a3ab7155SBob Copeland old_inode->i_ctime = CURRENT_TIME_SEC; 398013e4f4aSAl Viro mark_inode_dirty(old_inode); 399a3ab7155SBob Copeland out: 400a3ab7155SBob Copeland return err; 401a3ab7155SBob Copeland } 402a3ab7155SBob Copeland 403a3ab7155SBob Copeland static int omfs_readdir(struct file *filp, void *dirent, filldir_t filldir) 404a3ab7155SBob Copeland { 405a3ab7155SBob Copeland struct inode *dir = filp->f_dentry->d_inode; 406a3ab7155SBob Copeland struct buffer_head *bh; 407a3ab7155SBob Copeland loff_t offset, res; 408a3ab7155SBob Copeland unsigned int hchain, hindex; 409a3ab7155SBob Copeland int nbuckets; 410a3ab7155SBob Copeland u64 fsblock; 411a3ab7155SBob Copeland int ret = -EINVAL; 412a3ab7155SBob Copeland 413a3ab7155SBob Copeland if (filp->f_pos >> 32) 414a3ab7155SBob Copeland goto success; 415a3ab7155SBob Copeland 416a3ab7155SBob Copeland switch ((unsigned long) filp->f_pos) { 417a3ab7155SBob Copeland case 0: 418a3ab7155SBob Copeland if (filldir(dirent, ".", 1, 0, dir->i_ino, DT_DIR) < 0) 419a3ab7155SBob Copeland goto success; 420a3ab7155SBob Copeland filp->f_pos++; 421a3ab7155SBob Copeland /* fall through */ 422a3ab7155SBob Copeland case 1: 423a3ab7155SBob Copeland if (filldir(dirent, "..", 2, 1, 424a3ab7155SBob Copeland parent_ino(filp->f_dentry), DT_DIR) < 0) 425a3ab7155SBob Copeland goto success; 426a3ab7155SBob Copeland filp->f_pos = 1 << 20; 427a3ab7155SBob Copeland /* fall through */ 428a3ab7155SBob Copeland } 429a3ab7155SBob Copeland 430a3ab7155SBob Copeland nbuckets = (dir->i_size - OMFS_DIR_START) / 8; 431a3ab7155SBob Copeland 432a3ab7155SBob Copeland /* high 12 bits store bucket + 1 and low 20 bits store hash index */ 433a3ab7155SBob Copeland hchain = (filp->f_pos >> 20) - 1; 434a3ab7155SBob Copeland hindex = filp->f_pos & 0xfffff; 435a3ab7155SBob Copeland 436f068272cSBob Copeland bh = omfs_bread(dir->i_sb, dir->i_ino); 437a3ab7155SBob Copeland if (!bh) 438a3ab7155SBob Copeland goto out; 439a3ab7155SBob Copeland 440a3ab7155SBob Copeland offset = OMFS_DIR_START + hchain * 8; 441a3ab7155SBob Copeland 442a3ab7155SBob Copeland for (; hchain < nbuckets; hchain++, offset += 8) { 443a3ab7155SBob Copeland fsblock = be64_to_cpu(*((__be64 *) &bh->b_data[offset])); 444a3ab7155SBob Copeland 445a3ab7155SBob Copeland res = omfs_fill_chain(filp, dirent, filldir, fsblock, hindex); 446a3ab7155SBob Copeland hindex = 0; 447a3ab7155SBob Copeland if (res < 0) 448a3ab7155SBob Copeland break; 449a3ab7155SBob Copeland 450a3ab7155SBob Copeland filp->f_pos = (hchain+2) << 20; 451a3ab7155SBob Copeland } 452a3ab7155SBob Copeland brelse(bh); 453a3ab7155SBob Copeland success: 454a3ab7155SBob Copeland ret = 0; 455a3ab7155SBob Copeland out: 456a3ab7155SBob Copeland return ret; 457a3ab7155SBob Copeland } 458a3ab7155SBob Copeland 4596e1d5dccSAlexey Dobriyan const struct inode_operations omfs_dir_inops = { 460a3ab7155SBob Copeland .lookup = omfs_lookup, 461a3ab7155SBob Copeland .mkdir = omfs_mkdir, 462a3ab7155SBob Copeland .rename = omfs_rename, 463a3ab7155SBob Copeland .create = omfs_create, 464d932805bSAl Viro .unlink = omfs_remove, 465d932805bSAl Viro .rmdir = omfs_remove, 466a3ab7155SBob Copeland }; 467a3ab7155SBob Copeland 468828c0950SAlexey Dobriyan const struct file_operations omfs_dir_operations = { 469a3ab7155SBob Copeland .read = generic_read_dir, 470a3ab7155SBob Copeland .readdir = omfs_readdir, 4713222a3e5SChristoph Hellwig .llseek = generic_file_llseek, 472a3ab7155SBob Copeland }; 473