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                 hfs_find_exit(&fd);
  35                 if (res == -ENOENT) {
  36                         /* No such entry */
  37                         inode = NULL;
  38                         goto done;
  39                 }
  40                 return ERR_PTR(res);
  41         }
  42         inode = hfs_iget(dir->i_sb, &fd.search_key->cat, &rec);
  43         hfs_find_exit(&fd);
  44         if (!inode)
  45                 return ERR_PTR(-EACCES);
  46 done:
  47         d_add(dentry, inode);
  48         return NULL;
  49 }
  50
  51 /*
  52  * hfs_readdir
  53  */
  54 static int hfs_readdir(struct file *file, struct dir_context *ctx)
  55 {
  56         struct inode *inode = file_inode(file);
  57         struct super_block *sb = inode->i_sb;
  58         int len, err;
  59         char strbuf[HFS_MAX_NAMELEN];
  60         union hfs_cat_rec entry;
  61         struct hfs_find_data fd;
  62         struct hfs_readdir_data *rd;
  63         u16 type;
  64
  65         if (ctx->pos >= inode->i_size)
  66                 return 0;
  67
  68         err = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
  69         if (err)
  70                 return err;
  71         hfs_cat_build_key(sb, fd.search_key, inode->i_ino, NULL);
  72         err = hfs_brec_find(&fd);
  73         if (err)
  74                 goto out;
  75
  76         if (ctx->pos == 0) {
  77                 /* This is completely artificial... */
  78                 if (!dir_emit_dot(file, ctx))
  79                         goto out;
  80                 ctx->pos = 1;
  81         }
  82         if (ctx->pos == 1) {
  83                 if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
  84                         err = -EIO;
  85                         goto out;
  86                 }
  87
  88                 hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength);
  89                 if (entry.type != HFS_CDR_THD) {
  90                         pr_err("bad catalog folder thread\n");
  91                         err = -EIO;
  92                         goto out;
  93                 }
  94                 //if (fd.entrylength < HFS_MIN_THREAD_SZ) {
  95                 //      pr_err("truncated catalog thread\n");
  96                 //      err = -EIO;
  97                 //      goto out;
  98                 //}
  99                 if (!dir_emit(ctx, "..", 2,
 100                             be32_to_cpu(entry.thread.ParID), DT_DIR))
 101                         goto out;
 102                 ctx->pos = 2;
 103         }
 104         if (ctx->pos >= inode->i_size)
 105                 goto out;
 106         err = hfs_brec_goto(&fd, ctx->pos - 1);
 107         if (err)
 108                 goto out;
 109
 110         for (;;) {
 111                 if (be32_to_cpu(fd.key->cat.ParID) != inode->i_ino) {
 112                         pr_err("walked past end of dir\n");
 113                         err = -EIO;
 114                         goto out;
 115                 }
 116
 117                 if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
 118                         err = -EIO;
 119                         goto out;
 120                 }
 121
 122                 hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength);
 123                 type = entry.type;
 124                 len = hfs_mac2asc(sb, strbuf, &fd.key->cat.CName);
 125                 if (type == HFS_CDR_DIR) {
 126                         if (fd.entrylength < sizeof(struct hfs_cat_dir)) {
 127                                 pr_err("small dir entry\n");
 128                                 err = -EIO;
 129                                 goto out;
 130                         }
 131                         if (!dir_emit(ctx, strbuf, len,
 132                                     be32_to_cpu(entry.dir.DirID), DT_DIR))
 133                                 break;
 134                 } else if (type == HFS_CDR_FIL) {
 135                         if (fd.entrylength < sizeof(struct hfs_cat_file)) {
 136                                 pr_err("small file entry\n");
 137                                 err = -EIO;
 138                                 goto out;
 139                         }
 140                         if (!dir_emit(ctx, strbuf, len,
 141                                     be32_to_cpu(entry.file.FlNum), DT_REG))
 142                                 break;
 143                 } else {
 144                         pr_err("bad catalog entry type %d\n", type);
 145                         err = -EIO;
 146                         goto out;
 147                 }
 148                 ctx->pos++;
 149                 if (ctx->pos >= inode->i_size)
 150                         goto out;
 151                 err = hfs_brec_goto(&fd, 1);
 152                 if (err)
 153                         goto out;
 154         }
 155         rd = file->private_data;
 156         if (!rd) {
 157                 rd = kmalloc(sizeof(struct hfs_readdir_data), GFP_KERNEL);
 158                 if (!rd) {
 159                         err = -ENOMEM;
 160                         goto out;
 161                 }
 162                 file->private_data = rd;
 163                 rd->file = file;
 164                 spin_lock(&HFS_I(inode)->open_dir_lock);
 165                 list_add(&rd->list, &HFS_I(inode)->open_dir_list);
 166                 spin_unlock(&HFS_I(inode)->open_dir_lock);
 167         }
 168         /*
 169          * Can be done after the list insertion; exclusion with
 170          * hfs_delete_cat() is provided by directory lock.
 171          */
 172         memcpy(&rd->key, &fd.key, sizeof(struct hfs_cat_key));
 173 out:
 174         hfs_find_exit(&fd);
 175         return err;
 176 }
 177
 178 static int hfs_dir_release(struct inode *inode, struct file *file)
 179 {
 180         struct hfs_readdir_data *rd = file->private_data;
 181         if (rd) {
 182                 spin_lock(&HFS_I(inode)->open_dir_lock);
 183                 list_del(&rd->list);
 184                 spin_unlock(&HFS_I(inode)->open_dir_lock);
 185                 kfree(rd);
 186         }
 187         return 0;
 188 }
 189
 190 /*
 191  * hfs_create()
 192  *
 193  * This is the create() entry in the inode_operations structure for
 194  * regular HFS directories.  The purpose is to create a new file in
 195  * a directory and return a corresponding inode, given the inode for
 196  * the directory and the name (and its length) of the new file.
 197  */
 198 static int hfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 199                       bool excl)
 200 {
 201         struct inode *inode;
 202         int res;
 203
 204         inode = hfs_new_inode(dir, &dentry->d_name, mode);
 205         if (!inode)
 206                 return -ENOMEM;
 207
 208         res = hfs_cat_create(inode->i_ino, dir, &dentry->d_name, inode);
 209         if (res) {
 210                 clear_nlink(inode);
 211                 hfs_delete_inode(inode);
 212                 iput(inode);
 213                 return res;
 214         }
 215         d_instantiate(dentry, inode);
 216         mark_inode_dirty(inode);
 217         return 0;
 218 }
 219
 220 /*
 221  * hfs_mkdir()
 222  *
 223  * This is the mkdir() entry in the inode_operations structure for
 224  * regular HFS directories.  The purpose is to create a new directory
 225  * in a directory, given the inode for the parent directory and the
 226  * name (and its length) of the new directory.
 227  */
 228 static int hfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 229 {
 230         struct inode *inode;
 231         int res;
 232
 233         inode = hfs_new_inode(dir, &dentry->d_name, S_IFDIR | mode);
 234         if (!inode)
 235                 return -ENOMEM;
 236
 237         res = hfs_cat_create(inode->i_ino, dir, &dentry->d_name, inode);
 238         if (res) {
 239                 clear_nlink(inode);
 240                 hfs_delete_inode(inode);
 241                 iput(inode);
 242                 return res;
 243         }
 244         d_instantiate(dentry, inode);
 245         mark_inode_dirty(inode);
 246         return 0;
 247 }
 248
 249 /*
 250  * hfs_remove()
 251  *
 252  * This serves as both unlink() and rmdir() in the inode_operations
 253  * structure for regular HFS directories.  The purpose is to delete
 254  * an existing child, given the inode for the parent directory and
 255  * the name (and its length) of the existing directory.
 256  *
 257  * HFS does not have hardlinks, so both rmdir and unlink set the
 258  * link count to 0.  The only difference is the emptiness check.
 259  */
 260 static int hfs_remove(struct inode *dir, struct dentry *dentry)
 261 {
 262         struct inode *inode = d_inode(dentry);
 263         int res;
 264
 265         if (S_ISDIR(inode->i_mode) && inode->i_size != 2)
 266                 return -ENOTEMPTY;
 267         res = hfs_cat_delete(inode->i_ino, dir, &dentry->d_name);
 268         if (res)
 269                 return res;
 270         clear_nlink(inode);
 271         inode->i_ctime = CURRENT_TIME_SEC;
 272         hfs_delete_inode(inode);
 273         mark_inode_dirty(inode);
 274         return 0;
 275 }
 276
 277 /*
 278  * hfs_rename()
 279  *
 280  * This is the rename() entry in the inode_operations structure for
 281  * regular HFS directories.  The purpose is to rename an existing
 282  * file or directory, given the inode for the current directory and
 283  * the name (and its length) of the existing file/directory and the
 284  * inode for the new directory and the name (and its length) of the
 285  * new file/directory.
 286  * XXX: how do you handle must_be dir?
 287  */
 288 static int hfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 289                       struct inode *new_dir, struct dentry *new_dentry)
 290 {
 291         int res;
 292
 293         /* Unlink destination if it already exists */
 294         if (d_really_is_positive(new_dentry)) {
 295                 res = hfs_remove(new_dir, new_dentry);
 296                 if (res)
 297                         return res;
 298         }
 299
 300         res = hfs_cat_move(d_inode(old_dentry)->i_ino,
 301                            old_dir, &old_dentry->d_name,
 302                            new_dir, &new_dentry->d_name);
 303         if (!res)
 304                 hfs_cat_build_key(old_dir->i_sb,
 305                                   (btree_key *)&HFS_I(d_inode(old_dentry))->cat_key,
 306                                   new_dir->i_ino, &new_dentry->d_name);
 307         return res;
 308 }
 309
 310 const struct file_operations hfs_dir_operations = {
 311         .read           = generic_read_dir,
 312         .iterate_shared = hfs_readdir,
 313         .llseek         = generic_file_llseek,
 314         .release        = hfs_dir_release,
 315 };
 316
 317 const struct inode_operations hfs_dir_inode_operations = {
 318         .create         = hfs_create,
 319         .lookup         = hfs_lookup,
 320         .unlink         = hfs_remove,
 321         .mkdir          = hfs_mkdir,
 322         .rmdir          = hfs_remove,
 323         .rename         = hfs_rename,
 324         .setattr        = hfs_inode_setattr,
 325 };