root/fs/hfs/catalog.c

DEFINITIONS

1. hfs_cat_build_key
2. hfs_cat_build_record
3. hfs_cat_build_thread
4. hfs_cat_create
5. hfs_cat_keycmp
6. hfs_cat_find_brec
7. hfs_cat_delete
8. hfs_cat_move

   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  */
  23 void 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 
  36 static 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 
  65 static 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  */
  82 int 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 
 141 err1:
 142         hfs_cat_build_key(sb, fd.search_key, cnid, NULL);
 143         if (!hfs_brec_find(&fd))
 144                 hfs_brec_remove(&fd);
 145 err2:
 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  */
 171 int 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???
 187 int 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  */
 221 int 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;
 275 out:
 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  */
 288 int 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);
 379 out:
 380         hfs_bnode_put(dst_fd.bnode);
 381         hfs_find_exit(&src_fd);
 382         return err;
 383 }