LXR linux/fs/hfs/catalog.c

   1/*
   2 *  linux/fs/hfs/catalog.c
   3 *
   4 * Copyright (C) 1995-1997  Paul H. Hargrove
   5 * (C) 2003 Ardis Technologies <roman@ardistech.com>
   6 * This file may be distributed under the terms of the GNU General Public License.
   7 *
   8 * This file contains the functions related to the catalog B-tree.
   9 *
  10 * Cache code shamelessly stolen from
  11 *     linux/fs/inode.c Copyright (C) 1991, 1992  Linus Torvalds
  12 *     re-shamelessly stolen Copyright (C) 1997 Linus Torvalds
  13 */
  14
  15#include "hfs_fs.h"
  16#include "btree.h"
  17
  18/*
  19 * hfs_cat_build_key()
  20 *
  21 * Given the ID of the parent and the name build a search key.
  22 */
  23void hfs_cat_build_key(struct super_block *sb, btree_key *key, u32 parent, const struct qstr *name)
  24{
  25        key->cat.reserved = 0;
  26        key->cat.ParID = cpu_to_be32(parent);
  27        if (name) {
  28                hfs_asc2mac(sb, &key->cat.CName, name);
  29                key->key_len = 6 + key->cat.CName.len;
  30        } else {
  31                memset(&key->cat.CName, 0, sizeof(struct hfs_name));
  32                key->key_len = 6;
  33        }
  34}
  35
  36static int hfs_cat_build_record(hfs_cat_rec *rec, u32 cnid, struct inode *inode)
  37{
  38        __be32 mtime = hfs_mtime();
  39
  40        memset(rec, 0, sizeof(*rec));
  41        if (S_ISDIR(inode->i_mode)) {
  42                rec->type = HFS_CDR_DIR;
  43                rec->dir.DirID = cpu_to_be32(cnid);
  44                rec->dir.CrDat = mtime;
  45                rec->dir.MdDat = mtime;
  46                rec->dir.BkDat = 0;
  47                rec->dir.UsrInfo.frView = cpu_to_be16(0xff);
  48                return sizeof(struct hfs_cat_dir);
  49        } else {
  50                /* init some fields for the file record */
  51                rec->type = HFS_CDR_FIL;
  52                rec->file.Flags = HFS_FIL_USED | HFS_FIL_THD;
  53                if (!(inode->i_mode & S_IWUSR))
  54                        rec->file.Flags |= HFS_FIL_LOCK;
  55                rec->file.FlNum = cpu_to_be32(cnid);
  56                rec->file.CrDat = mtime;
  57                rec->file.MdDat = mtime;
  58                rec->file.BkDat = 0;
  59                rec->file.UsrWds.fdType = HFS_SB(inode->i_sb)->s_type;
  60                rec->file.UsrWds.fdCreator = HFS_SB(inode->i_sb)->s_creator;
  61                return sizeof(struct hfs_cat_file);
  62        }
  63}
  64
  65static int hfs_cat_build_thread(struct super_block *sb,
  66                                hfs_cat_rec *rec, int type,
  67                                u32 parentid, const struct qstr *name)
  68{
  69        rec->type = type;
  70        memset(rec->thread.reserved, 0, sizeof(rec->thread.reserved));
  71        rec->thread.ParID = cpu_to_be32(parentid);
  72        hfs_asc2mac(sb, &rec->thread.CName, name);
  73        return sizeof(struct hfs_cat_thread);
  74}
  75
  76/*
  77 * create_entry()
  78 *
  79 * Add a new file or directory to the catalog B-tree and
  80 * return a (struct hfs_cat_entry) for it in '*result'.
  81 */
  82int hfs_cat_create(u32 cnid, struct inode *dir, const struct qstr *str, struct inode *inode)
  83{
  84        struct hfs_find_data fd;
  85        struct super_block *sb;
  86        union hfs_cat_rec entry;
  87        int entry_size;
  88        int err;
  89
  90        hfs_dbg(CAT_MOD, "create_cat: %s,%u(%d)\n",
  91                str->name, cnid, inode->i_nlink);
  92        if (dir->i_size >= HFS_MAX_VALENCE)
  93                return -ENOSPC;
  94
  95        sb = dir->i_sb;
  96        err = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
  97        if (err)
  98                return err;
  99
 100        /*
 101         * Fail early and avoid ENOSPC during the btree operations. We may
 102         * have to split the root node at most once.
 103         */
 104        err = hfs_bmap_reserve(fd.tree, 2 * fd.tree->depth);
 105        if (err)
 106                goto err2;
 107
 108        hfs_cat_build_key(sb, fd.search_key, cnid, NULL);
 109        entry_size = hfs_cat_build_thread(sb, &entry, S_ISDIR(inode->i_mode) ?
 110                        HFS_CDR_THD : HFS_CDR_FTH,
 111                        dir->i_ino, str);
 112        err = hfs_brec_find(&fd);
 113        if (err != -ENOENT) {
 114                if (!err)
 115                        err = -EEXIST;
 116                goto err2;
 117        }
 118        err = hfs_brec_insert(&fd, &entry, entry_size);
 119        if (err)
 120                goto err2;
 121
 122        hfs_cat_build_key(sb, fd.search_key, dir->i_ino, str);
 123        entry_size = hfs_cat_build_record(&entry, cnid, inode);
 124        err = hfs_brec_find(&fd);
 125        if (err != -ENOENT) {
 126                /* panic? */
 127                if (!err)
 128                        err = -EEXIST;
 129                goto err1;
 130        }
 131        err = hfs_brec_insert(&fd, &entry, entry_size);
 132        if (err)
 133                goto err1;
 134
 135        dir->i_size++;
 136        dir->i_mtime = dir->i_ctime = current_time(dir);
 137        mark_inode_dirty(dir);
 138        hfs_find_exit(&fd);
 139        return 0;
 140
 141err1:
 142        hfs_cat_build_key(sb, fd.search_key, cnid, NULL);
 143        if (!hfs_brec_find(&fd))
 144                hfs_brec_remove(&fd);
 145err2:
 146        hfs_find_exit(&fd);
 147        return err;
 148}
 149
 150/*
 151 * hfs_cat_compare()
 152 *
 153 * Description:
 154 *   This is the comparison function used for the catalog B-tree.  In
 155 *   comparing catalog B-tree entries, the parent id is the most
 156 *   significant field (compared as unsigned ints).  The name field is
 157 *   the least significant (compared in "Macintosh lexical order",
 158 *   see hfs_strcmp() in string.c)
 159 * Input Variable(s):
 160 *   struct hfs_cat_key *key1: pointer to the first key to compare
 161 *   struct hfs_cat_key *key2: pointer to the second key to compare
 162 * Output Variable(s):
 163 *   NONE
 164 * Returns:
 165 *   int: negative if key1<key2, positive if key1>key2, and 0 if key1==key2
 166 * Preconditions:
 167 *   key1 and key2 point to "valid" (struct hfs_cat_key)s.
 168 * Postconditions:
 169 *   This function has no side-effects
 170 */
 171int hfs_cat_keycmp(const btree_key *key1, const btree_key *key2)
 172{
 173        __be32 k1p, k2p;
 174
 175        k1p = key1->cat.ParID;
 176        k2p = key2->cat.ParID;
 177
 178        if (k1p != k2p)
 179                return be32_to_cpu(k1p) < be32_to_cpu(k2p) ? -1 : 1;
 180
 181        return hfs_strcmp(key1->cat.CName.name, key1->cat.CName.len,
 182                          key2->cat.CName.name, key2->cat.CName.len);
 183}
 184
 185/* Try to get a catalog entry for given catalog id */
 186// move to read_super???
 187int hfs_cat_find_brec(struct super_block *sb, u32 cnid,
 188                      struct hfs_find_data *fd)
 189{
 190        hfs_cat_rec rec;
 191        int res, len, type;
 192
 193        hfs_cat_build_key(sb, fd->search_key, cnid, NULL);
 194        res = hfs_brec_read(fd, &rec, sizeof(rec));
 195        if (res)
 196                return res;
 197
 198        type = rec.type;
 199        if (type != HFS_CDR_THD && type != HFS_CDR_FTH) {
 200                pr_err("found bad thread record in catalog\n");
 201                return -EIO;
 202        }
 203
 204        fd->search_key->cat.ParID = rec.thread.ParID;
 205        len = fd->search_key->cat.CName.len = rec.thread.CName.len;
 206        if (len > HFS_NAMELEN) {
 207                pr_err("bad catalog namelength\n");
 208                return -EIO;
 209        }
 210        memcpy(fd->search_key->cat.CName.name, rec.thread.CName.name, len);
 211        return hfs_brec_find(fd);
 212}
 213
 214
 215/*
 216 * hfs_cat_delete()
 217 *
 218 * Delete the indicated file or directory.
 219 * The associated thread is also removed unless ('with_thread'==0).
 220 */
 221int hfs_cat_delete(u32 cnid, struct inode *dir, const struct qstr *str)
 222{
 223        struct super_block *sb;
 224        struct hfs_find_data fd;
 225        struct hfs_readdir_data *rd;
 226        int res, type;
 227
 228        hfs_dbg(CAT_MOD, "delete_cat: %s,%u\n", str ? str->name : NULL, cnid);
 229        sb = dir->i_sb;
 230        res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
 231        if (res)
 232                return res;
 233
 234        hfs_cat_build_key(sb, fd.search_key, dir->i_ino, str);
 235        res = hfs_brec_find(&fd);
 236        if (res)
 237                goto out;
 238
 239        type = hfs_bnode_read_u8(fd.bnode, fd.entryoffset);
 240        if (type == HFS_CDR_FIL) {
 241                struct hfs_cat_file file;
 242                hfs_bnode_read(fd.bnode, &file, fd.entryoffset, sizeof(file));
 243                if (be32_to_cpu(file.FlNum) == cnid) {
 244#if 0
 245                        hfs_free_fork(sb, &file, HFS_FK_DATA);
 246#endif
 247                        hfs_free_fork(sb, &file, HFS_FK_RSRC);
 248                }
 249        }
 250
 251        /* we only need to take spinlock for exclusion with ->release() */
 252        spin_lock(&HFS_I(dir)->open_dir_lock);
 253        list_for_each_entry(rd, &HFS_I(dir)->open_dir_list, list) {
 254                if (fd.tree->keycmp(fd.search_key, (void *)&rd->key) < 0)
 255                        rd->file->f_pos--;
 256        }
 257        spin_unlock(&HFS_I(dir)->open_dir_lock);
 258
 259        res = hfs_brec_remove(&fd);
 260        if (res)
 261                goto out;
 262
 263        hfs_cat_build_key(sb, fd.search_key, cnid, NULL);
 264        res = hfs_brec_find(&fd);
 265        if (!res) {
 266                res = hfs_brec_remove(&fd);
 267                if (res)
 268                        goto out;
 269        }
 270
 271        dir->i_size--;
 272        dir->i_mtime = dir->i_ctime = current_time(dir);
 273        mark_inode_dirty(dir);
 274        res = 0;
 275out:
 276        hfs_find_exit(&fd);
 277
 278        return res;
 279}
 280
 281/*
 282 * hfs_cat_move()
 283 *
 284 * Rename a file or directory, possibly to a new directory.
 285 * If the destination exists it is removed and a
 286 * (struct hfs_cat_entry) for it is returned in '*result'.
 287 */
 288int hfs_cat_move(u32 cnid, struct inode *src_dir, const struct qstr *src_name,
 289                 struct inode *dst_dir, const struct qstr *dst_name)
 290{
 291        struct super_block *sb;
 292        struct hfs_find_data src_fd, dst_fd;
 293        union hfs_cat_rec entry;
 294        int entry_size, type;
 295        int err;
 296
 297        hfs_dbg(CAT_MOD, "rename_cat: %u - %lu,%s - %lu,%s\n",
 298                cnid, src_dir->i_ino, src_name->name,
 299                dst_dir->i_ino, dst_name->name);
 300        sb = src_dir->i_sb;
 301        err = hfs_find_init(HFS_SB(sb)->cat_tree, &src_fd);
 302        if (err)
 303                return err;
 304        dst_fd = src_fd;
 305
 306        /*
 307         * Fail early and avoid ENOSPC during the btree operations. We may
 308         * have to split the root node at most once.
 309         */
 310        err = hfs_bmap_reserve(src_fd.tree, 2 * src_fd.tree->depth);
 311        if (err)
 312                goto out;
 313
 314        /* find the old dir entry and read the data */
 315        hfs_cat_build_key(sb, src_fd.search_key, src_dir->i_ino, src_name);
 316        err = hfs_brec_find(&src_fd);
 317        if (err)
 318                goto out;
 319        if (src_fd.entrylength > sizeof(entry) || src_fd.entrylength < 0) {
 320                err = -EIO;
 321                goto out;
 322        }
 323
 324        hfs_bnode_read(src_fd.bnode, &entry, src_fd.entryoffset,
 325                            src_fd.entrylength);
 326
 327        /* create new dir entry with the data from the old entry */
 328        hfs_cat_build_key(sb, dst_fd.search_key, dst_dir->i_ino, dst_name);
 329        err = hfs_brec_find(&dst_fd);
 330        if (err != -ENOENT) {
 331                if (!err)
 332                        err = -EEXIST;
 333                goto out;
 334        }
 335
 336        err = hfs_brec_insert(&dst_fd, &entry, src_fd.entrylength);
 337        if (err)
 338                goto out;
 339        dst_dir->i_size++;
 340        dst_dir->i_mtime = dst_dir->i_ctime = current_time(dst_dir);
 341        mark_inode_dirty(dst_dir);
 342
 343        /* finally remove the old entry */
 344        hfs_cat_build_key(sb, src_fd.search_key, src_dir->i_ino, src_name);
 345        err = hfs_brec_find(&src_fd);
 346        if (err)
 347                goto out;
 348        err = hfs_brec_remove(&src_fd);
 349        if (err)
 350                goto out;
 351        src_dir->i_size--;
 352        src_dir->i_mtime = src_dir->i_ctime = current_time(src_dir);
 353        mark_inode_dirty(src_dir);
 354
 355        type = entry.type;
 356        if (type == HFS_CDR_FIL && !(entry.file.Flags & HFS_FIL_THD))
 357                goto out;
 358
 359        /* remove old thread entry */
 360        hfs_cat_build_key(sb, src_fd.search_key, cnid, NULL);
 361        err = hfs_brec_find(&src_fd);
 362        if (err)
 363                goto out;
 364        err = hfs_brec_remove(&src_fd);
 365        if (err)
 366                goto out;
 367
 368        /* create new thread entry */
 369        hfs_cat_build_key(sb, dst_fd.search_key, cnid, NULL);
 370        entry_size = hfs_cat_build_thread(sb, &entry, type == HFS_CDR_FIL ? HFS_CDR_FTH : HFS_CDR_THD,
 371                                        dst_dir->i_ino, dst_name);
 372        err = hfs_brec_find(&dst_fd);
 373        if (err != -ENOENT) {
 374                if (!err)
 375                        err = -EEXIST;
 376                goto out;
 377        }
 378        err = hfs_brec_insert(&dst_fd, &entry, entry_size);
 379out:
 380        hfs_bnode_put(dst_fd.bnode);
 381        hfs_find_exit(&src_fd);
 382        return err;
 383}
 384