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                                  unsigned int flags)
  22 {
  23         hfs_cat_rec rec;
  24         struct hfs_find_data fd;
  25         struct inode *inode = NULL;
  26         int res;
  27
  28         res = hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);
  29         if (res)
  30                 return ERR_PTR(res);
  31         hfs_cat_build_key(dir->i_sb, fd.search_key, dir->i_ino, &dentry->d_name);
  32         res = hfs_brec_read(&fd, &rec, sizeof(rec));
  33         if (res) {
  34                 if (res != -ENOENT)
  35                         inode = ERR_PTR(res);
  36         } else {
  37                 inode = hfs_iget(dir->i_sb, &fd.search_key->cat, &rec);
  38                 if (!inode)
  39                         inode = ERR_PTR(-EACCES);
  40         }
  41         hfs_find_exit(&fd);
  42         return d_splice_alias(inode, dentry);
  43 }
  44
  45 /*
  46  * hfs_readdir
  47  */
  48 static int hfs_readdir(struct file *file, struct dir_context *ctx)
  49 {
  50         struct inode *inode = file_inode(file);
  51         struct super_block *sb = inode->i_sb;
  52         int len, err;
  53         char strbuf[HFS_MAX_NAMELEN];
  54         union hfs_cat_rec entry;
  55         struct hfs_find_data fd;
  56         struct hfs_readdir_data *rd;
  57         u16 type;
  58
  59         if (ctx->pos >= inode->i_size)
  60                 return 0;
  61
  62         err = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
  63         if (err)
  64                 return err;
  65         hfs_cat_build_key(sb, fd.search_key, inode->i_ino, NULL);
  66         err = hfs_brec_find(&fd);
  67         if (err)
  68                 goto out;
  69
  70         if (ctx->pos == 0) {
  71                 /* This is completely artificial... */
  72                 if (!dir_emit_dot(file, ctx))
  73                         goto out;
  74                 ctx->pos = 1;
  75         }
  76         if (ctx->pos == 1) {
  77                 if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
  78                         err = -EIO;
  79                         goto out;
  80                 }
  81
  82                 hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength);
  83                 if (entry.type != HFS_CDR_THD) {
  84                         pr_err("bad catalog folder thread\n");
  85                         err = -EIO;
  86                         goto out;
  87                 }
  88                 //if (fd.entrylength < HFS_MIN_THREAD_SZ) {
  89                 //      pr_err("truncated catalog thread\n");
  90                 //      err = -EIO;
  91                 //      goto out;
  92                 //}
  93                 if (!dir_emit(ctx, "..", 2,
  94                             be32_to_cpu(entry.thread.ParID), DT_DIR))
  95                         goto out;
  96                 ctx->pos = 2;
  97         }
  98         if (ctx->pos >= inode->i_size)
  99                 goto out;
 100         err = hfs_brec_goto(&fd, ctx->pos - 1);
 101         if (err)
 102                 goto out;
 103
 104         for (;;) {
 105                 if (be32_to_cpu(fd.key->cat.ParID) != inode->i_ino) {
 106                         pr_err("walked past end of dir\n");
 107                         err = -EIO;
 108                         goto out;
 109                 }
 110
 111                 if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
 112                         err = -EIO;
 113                         goto out;
 114                 }
 115
 116                 hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength);
 117                 type = entry.type;
 118                 len = hfs_mac2asc(sb, strbuf, &fd.key->cat.CName);
 119                 if (type == HFS_CDR_DIR) {
 120                         if (fd.entrylength < sizeof(struct hfs_cat_dir)) {
 121                                 pr_err("small dir entry\n");
 122                                 err = -EIO;
 123                                 goto out;
 124                         }
 125                         if (!dir_emit(ctx, strbuf, len,
 126                                     be32_to_cpu(entry.dir.DirID), DT_DIR))
 127                                 break;
 128                 } else if (type == HFS_CDR_FIL) {
 129                         if (fd.entrylength < sizeof(struct hfs_cat_file)) {
 130                                 pr_err("small file entry\n");
 131                                 err = -EIO;
 132                                 goto out;
 133                         }
 134                         if (!dir_emit(ctx, strbuf, len,
 135                                     be32_to_cpu(entry.file.FlNum), DT_REG))
 136                                 break;
 137                 } else {
 138                         pr_err("bad catalog entry type %d\n", type);
 139                         err = -EIO;
 140                         goto out;
 141                 }
 142                 ctx->pos++;
 143                 if (ctx->pos >= inode->i_size)
 144                         goto out;
 145                 err = hfs_brec_goto(&fd, 1);
 146                 if (err)
 147                         goto out;
 148         }
 149         rd = file->private_data;
 150         if (!rd) {
 151                 rd = kmalloc(sizeof(struct hfs_readdir_data), GFP_KERNEL);
 152                 if (!rd) {
 153                         err = -ENOMEM;
 154                         goto out;
 155                 }
 156                 file->private_data = rd;
 157                 rd->file = file;
 158                 spin_lock(&HFS_I(inode)->open_dir_lock);
 159                 list_add(&rd->list, &HFS_I(inode)->open_dir_list);
 160                 spin_unlock(&HFS_I(inode)->open_dir_lock);
 161         }
 162         /*
 163          * Can be done after the list insertion; exclusion with
 164          * hfs_delete_cat() is provided by directory lock.
 165          */
 166         memcpy(&rd->key, &fd.key->cat, sizeof(struct hfs_cat_key));
 167 out:
 168         hfs_find_exit(&fd);
 169         return err;
 170 }
 171
 172 static int hfs_dir_release(struct inode *inode, struct file *file)
 173 {
 174         struct hfs_readdir_data *rd = file->private_data;
 175         if (rd) {
 176                 spin_lock(&HFS_I(inode)->open_dir_lock);
 177                 list_del(&rd->list);
 178                 spin_unlock(&HFS_I(inode)->open_dir_lock);
 179                 kfree(rd);
 180         }
 181         return 0;
 182 }
 183
 184 /*
 185  * hfs_create()
 186  *
 187  * This is the create() entry in the inode_operations structure for
 188  * regular HFS directories.  The purpose is to create a new file in
 189  * a directory and return a corresponding inode, given the inode for
 190  * the directory and the name (and its length) of the new file.
 191  */
 192 static int hfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 193                       bool excl)
 194 {
 195         struct inode *inode;
 196         int res;
 197
 198         inode = hfs_new_inode(dir, &dentry->d_name, mode);
 199         if (!inode)
 200                 return -ENOMEM;
 201
 202         res = hfs_cat_create(inode->i_ino, dir, &dentry->d_name, inode);
 203         if (res) {
 204                 clear_nlink(inode);
 205                 hfs_delete_inode(inode);
 206                 iput(inode);
 207                 return res;
 208         }
 209         d_instantiate(dentry, inode);
 210         mark_inode_dirty(inode);
 211         return 0;
 212 }
 213
 214 /*
 215  * hfs_mkdir()
 216  *
 217  * This is the mkdir() entry in the inode_operations structure for
 218  * regular HFS directories.  The purpose is to create a new directory
 219  * in a directory, given the inode for the parent directory and the
 220  * name (and its length) of the new directory.
 221  */
 222 static int hfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 223 {
 224         struct inode *inode;
 225         int res;
 226
 227         inode = hfs_new_inode(dir, &dentry->d_name, S_IFDIR | mode);
 228         if (!inode)
 229                 return -ENOMEM;
 230
 231         res = hfs_cat_create(inode->i_ino, dir, &dentry->d_name, inode);
 232         if (res) {
 233                 clear_nlink(inode);
 234                 hfs_delete_inode(inode);
 235                 iput(inode);
 236                 return res;
 237         }
 238         d_instantiate(dentry, inode);
 239         mark_inode_dirty(inode);
 240         return 0;
 241 }
 242
 243 /*
 244  * hfs_remove()
 245  *
 246  * This serves as both unlink() and rmdir() in the inode_operations
 247  * structure for regular HFS directories.  The purpose is to delete
 248  * an existing child, given the inode for the parent directory and
 249  * the name (and its length) of the existing directory.
 250  *
 251  * HFS does not have hardlinks, so both rmdir and unlink set the
 252  * link count to 0.  The only difference is the emptiness check.
 253  */
 254 static int hfs_remove(struct inode *dir, struct dentry *dentry)
 255 {
 256         struct inode *inode = d_inode(dentry);
 257         int res;
 258
 259         if (S_ISDIR(inode->i_mode) && inode->i_size != 2)
 260                 return -ENOTEMPTY;
 261         res = hfs_cat_delete(inode->i_ino, dir, &dentry->d_name);
 262         if (res)
 263                 return res;
 264         clear_nlink(inode);
 265         inode->i_ctime = current_time(inode);
 266         hfs_delete_inode(inode);
 267         mark_inode_dirty(inode);
 268         return 0;
 269 }
 270
 271 /*
 272  * hfs_rename()
 273  *
 274  * This is the rename() entry in the inode_operations structure for
 275  * regular HFS directories.  The purpose is to rename an existing
 276  * file or directory, given the inode for the current directory and
 277  * the name (and its length) of the existing file/directory and the
 278  * inode for the new directory and the name (and its length) of the
 279  * new file/directory.
 280  * XXX: how do you handle must_be dir?
 281  */
 282 static int hfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 283                       struct inode *new_dir, struct dentry *new_dentry,
 284                       unsigned int flags)
 285 {
 286         int res;
 287
 288         if (flags & ~RENAME_NOREPLACE)
 289                 return -EINVAL;
 290
 291         /* Unlink destination if it already exists */
 292         if (d_really_is_positive(new_dentry)) {
 293                 res = hfs_remove(new_dir, new_dentry);
 294                 if (res)
 295                         return res;
 296         }
 297
 298         res = hfs_cat_move(d_inode(old_dentry)->i_ino,
 299                            old_dir, &old_dentry->d_name,
 300                            new_dir, &new_dentry->d_name);
 301         if (!res)
 302                 hfs_cat_build_key(old_dir->i_sb,
 303                                   (btree_key *)&HFS_I(d_inode(old_dentry))->cat_key,
 304                                   new_dir->i_ino, &new_dentry->d_name);
 305         return res;
 306 }
 307
 308 const struct file_operations hfs_dir_operations = {
 309         .read           = generic_read_dir,
 310         .iterate_shared = hfs_readdir,
 311         .llseek         = generic_file_llseek,
 312         .release        = hfs_dir_release,
 313 };
 314
 315 const struct inode_operations hfs_dir_inode_operations = {
 316         .create         = hfs_create,
 317         .lookup         = hfs_lookup,
 318         .unlink         = hfs_remove,
 319         .mkdir          = hfs_mkdir,
 320         .rmdir          = hfs_remove,
 321         .rename         = hfs_rename,
 322         .setattr        = hfs_inode_setattr,
 323 };