fs/hfs/dir.c

   1 /*
   2  *  linux/fs/hfs/dir.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 directory-related functions independent of which
   9  * scheme is being used to represent forks.
  10  *
  11  * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
  12  */
  13
  14 #include "hfs_fs.h"
  15 #include "btree.h"
  16
  17 /*
  18  * hfs_lookup()
  19  */
  20 static struct dentry *hfs_lookup(struct inode *dir, struct dentry *dentry,
  21                                  struct nameidata *nd)
  22 {
  23         hfs_cat_rec rec;
  24         struct hfs_find_data fd;
  25         struct inode *inode = NULL;
  26         int res;
  27
  28         hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);
  29         hfs_cat_build_key(dir->i_sb, fd.search_key, dir->i_ino, &dentry->d_name);
  30         res = hfs_brec_read(&fd, &rec, sizeof(rec));
  31         if (res) {
  32                 hfs_find_exit(&fd);
  33                 if (res == -ENOENT) {
  34                         /* No such entry */
  35                         inode = NULL;
  36                         goto done;
  37                 }
  38                 return ERR_PTR(res);
  39         }
  40         inode = hfs_iget(dir->i_sb, &fd.search_key->cat, &rec);
  41         hfs_find_exit(&fd);
  42         if (!inode)
  43                 return ERR_PTR(-EACCES);
  44 done:
  45         d_add(dentry, inode);
  46         return NULL;
  47 }
  48
  49 /*
  50  * hfs_readdir
  51  */
  52 static int hfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
  53 {
  54         struct inode *inode = filp->f_path.dentry->d_inode;
  55         struct super_block *sb = inode->i_sb;
  56         int len, err;
  57         char strbuf[HFS_MAX_NAMELEN];
  58         union hfs_cat_rec entry;
  59         struct hfs_find_data fd;
  60         struct hfs_readdir_data *rd;
  61         u16 type;
  62
  63         if (filp->f_pos >= inode->i_size)
  64                 return 0;
  65
  66         hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
  67         hfs_cat_build_key(sb, fd.search_key, inode->i_ino, NULL);
  68         err = hfs_brec_find(&fd);
  69         if (err)
  70                 goto out;
  71
  72         switch ((u32)filp->f_pos) {
  73         case 0:
  74                 /* This is completely artificial... */
  75                 if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR))
  76                         goto out;
  77                 filp->f_pos++;
  78                 /* fall through */
  79         case 1:
  80                 if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
  81                         err = -EIO;
  82                         goto out;
  83                 }
  84
  85                 hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength);
  86                 if (entry.type != HFS_CDR_THD) {
  87                         printk(KERN_ERR "hfs: bad catalog folder thread\n");
  88                         err = -EIO;
  89                         goto out;
  90                 }
  91                 //if (fd.entrylength < HFS_MIN_THREAD_SZ) {
  92                 //      printk(KERN_ERR "hfs: truncated catalog thread\n");
  93                 //      err = -EIO;
  94                 //      goto out;
  95                 //}
  96                 if (filldir(dirent, "..", 2, 1,
  97                             be32_to_cpu(entry.thread.ParID), DT_DIR))
  98                         goto out;
  99                 filp->f_pos++;
 100                 /* fall through */
 101         default:
 102                 if (filp->f_pos >= inode->i_size)
 103                         goto out;
 104                 err = hfs_brec_goto(&fd, filp->f_pos - 1);
 105                 if (err)
 106                         goto out;
 107         }
 108
 109         for (;;) {
 110                 if (be32_to_cpu(fd.key->cat.ParID) != inode->i_ino) {
 111                         printk(KERN_ERR "hfs: walked past end of dir\n");
 112                         err = -EIO;
 113                         goto out;
 114                 }
 115
 116                 if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
 117                         err = -EIO;
 118                         goto out;
 119                 }
 120
 121                 hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength);
 122                 type = entry.type;
 123                 len = hfs_mac2asc(sb, strbuf, &fd.key->cat.CName);
 124                 if (type == HFS_CDR_DIR) {
 125                         if (fd.entrylength < sizeof(struct hfs_cat_dir)) {
 126                                 printk(KERN_ERR "hfs: small dir entry\n");
 127                                 err = -EIO;
 128                                 goto out;
 129                         }
 130                         if (filldir(dirent, strbuf, len, filp->f_pos,
 131                                     be32_to_cpu(entry.dir.DirID), DT_DIR))
 132                                 break;
 133                 } else if (type == HFS_CDR_FIL) {
 134                         if (fd.entrylength < sizeof(struct hfs_cat_file)) {
 135                                 printk(KERN_ERR "hfs: small file entry\n");
 136                                 err = -EIO;
 137                                 goto out;
 138                         }
 139                         if (filldir(dirent, strbuf, len, filp->f_pos,
 140                                     be32_to_cpu(entry.file.FlNum), DT_REG))
 141                                 break;
 142                 } else {
 143                         printk(KERN_ERR "hfs: bad catalog entry type %d\n", type);
 144                         err = -EIO;
 145                         goto out;
 146                 }
 147                 filp->f_pos++;
 148                 if (filp->f_pos >= inode->i_size)
 149                         goto out;
 150                 err = hfs_brec_goto(&fd, 1);
 151                 if (err)
 152                         goto out;
 153         }
 154         rd = filp->private_data;
 155         if (!rd) {
 156                 rd = kmalloc(sizeof(struct hfs_readdir_data), GFP_KERNEL);
 157                 if (!rd) {
 158                         err = -ENOMEM;
 159                         goto out;
 160                 }
 161                 filp->private_data = rd;
 162                 rd->file = filp;
 163                 list_add(&rd->list, &HFS_I(inode)->open_dir_list);
 164         }
 165         memcpy(&rd->key, &fd.key, sizeof(struct hfs_cat_key));
 166 out:
 167         hfs_find_exit(&fd);
 168         return err;
 169 }
 170
 171 static int hfs_dir_release(struct inode *inode, struct file *file)
 172 {
 173         struct hfs_readdir_data *rd = file->private_data;
 174         if (rd) {
 175                 list_del(&rd->list);
 176                 kfree(rd);
 177         }
 178         return 0;
 179 }
 180
 181 /*
 182  * hfs_create()
 183  *
 184  * This is the create() entry in the inode_operations structure for
 185  * regular HFS directories.  The purpose is to create a new file in
 186  * a directory and return a corresponding inode, given the inode for
 187  * the directory and the name (and its length) of the new file.
 188  */
 189 static int hfs_create(struct inode *dir, struct dentry *dentry, int mode,
 190                       struct nameidata *nd)
 191 {
 192         struct inode *inode;
 193         int res;
 194
 195         inode = hfs_new_inode(dir, &dentry->d_name, mode);
 196         if (!inode)
 197                 return -ENOSPC;
 198
 199         res = hfs_cat_create(inode->i_ino, dir, &dentry->d_name, inode);
 200         if (res) {
 201                 inode->i_nlink = 0;
 202                 hfs_delete_inode(inode);
 203                 iput(inode);
 204                 return res;
 205         }
 206         d_instantiate(dentry, inode);
 207         mark_inode_dirty(inode);
 208         return 0;
 209 }
 210
 211 /*
 212  * hfs_mkdir()
 213  *
 214  * This is the mkdir() entry in the inode_operations structure for
 215  * regular HFS directories.  The purpose is to create a new directory
 216  * in a directory, given the inode for the parent directory and the
 217  * name (and its length) of the new directory.
 218  */
 219 static int hfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 220 {
 221         struct inode *inode;
 222         int res;
 223
 224         inode = hfs_new_inode(dir, &dentry->d_name, S_IFDIR | mode);
 225         if (!inode)
 226                 return -ENOSPC;
 227
 228         res = hfs_cat_create(inode->i_ino, dir, &dentry->d_name, inode);
 229         if (res) {
 230                 inode->i_nlink = 0;
 231                 hfs_delete_inode(inode);
 232                 iput(inode);
 233                 return res;
 234         }
 235         d_instantiate(dentry, inode);
 236         mark_inode_dirty(inode);
 237         return 0;
 238 }
 239
 240 /*
 241  * hfs_remove()
 242  *
 243  * This serves as both unlink() and rmdir() in the inode_operations
 244  * structure for regular HFS directories.  The purpose is to delete
 245  * an existing child, given the inode for the parent directory and
 246  * the name (and its length) of the existing directory.
 247  *
 248  * HFS does not have hardlinks, so both rmdir and unlink set the
 249  * link count to 0.  The only difference is the emptiness check.
 250  */
 251 static int hfs_remove(struct inode *dir, struct dentry *dentry)
 252 {
 253         struct inode *inode = dentry->d_inode;
 254         int res;
 255
 256         if (S_ISDIR(inode->i_mode) && inode->i_size != 2)
 257                 return -ENOTEMPTY;
 258         res = hfs_cat_delete(inode->i_ino, dir, &dentry->d_name);
 259         if (res)
 260                 return res;
 261         clear_nlink(inode);
 262         inode->i_ctime = CURRENT_TIME_SEC;
 263         hfs_delete_inode(inode);
 264         mark_inode_dirty(inode);
 265         return 0;
 266 }
 267
 268 /*
 269  * hfs_rename()
 270  *
 271  * This is the rename() entry in the inode_operations structure for
 272  * regular HFS directories.  The purpose is to rename an existing
 273  * file or directory, given the inode for the current directory and
 274  * the name (and its length) of the existing file/directory and the
 275  * inode for the new directory and the name (and its length) of the
 276  * new file/directory.
 277  * XXX: how do you handle must_be dir?
 278  */
 279 static int hfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 280                       struct inode *new_dir, struct dentry *new_dentry)
 281 {
 282         int res;
 283
 284         /* Unlink destination if it already exists */
 285         if (new_dentry->d_inode) {
 286                 res = hfs_remove(new_dir, new_dentry);
 287                 if (res)
 288                         return res;
 289         }
 290
 291         res = hfs_cat_move(old_dentry->d_inode->i_ino,
 292                            old_dir, &old_dentry->d_name,
 293                            new_dir, &new_dentry->d_name);
 294         if (!res)
 295                 hfs_cat_build_key(old_dir->i_sb,
 296                                   (btree_key *)&HFS_I(old_dentry->d_inode)->cat_key,
 297                                   new_dir->i_ino, &new_dentry->d_name);
 298         return res;
 299 }
 300
 301 const struct file_operations hfs_dir_operations = {
 302         .read           = generic_read_dir,
 303         .readdir        = hfs_readdir,
 304         .llseek         = generic_file_llseek,
 305         .release        = hfs_dir_release,
 306 };
 307
 308 const struct inode_operations hfs_dir_inode_operations = {
 309         .create         = hfs_create,
 310         .lookup         = hfs_lookup,
 311         .unlink         = hfs_remove,
 312         .mkdir          = hfs_mkdir,
 313         .rmdir          = hfs_remove,
 314         .rename         = hfs_rename,
 315         .setattr        = hfs_inode_setattr,
 316 };