linux/fs/hfs/dir.c
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   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 */
  20static 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);
  46done:
  47        d_add(dentry, inode);
  48        return NULL;
  49}
  50
  51/*
  52 * hfs_readdir
  53 */
  54static 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                list_add(&rd->list, &HFS_I(inode)->open_dir_list);
 165        }
 166        memcpy(&rd->key, &fd.key, sizeof(struct hfs_cat_key));
 167out:
 168        hfs_find_exit(&fd);
 169        return err;
 170}
 171
 172static int hfs_dir_release(struct inode *inode, struct file *file)
 173{
 174        struct hfs_readdir_data *rd = file->private_data;
 175        if (rd) {
 176                mutex_lock(&inode->i_mutex);
 177                list_del(&rd->list);
 178                mutex_unlock(&inode->i_mutex);
 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 */
 192static 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 -ENOSPC;
 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 */
 222static 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 -ENOSPC;
 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 */
 254static int hfs_remove(struct inode *dir, struct dentry *dentry)
 255{
 256        struct inode *inode = dentry->d_inode;
 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_SEC;
 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 */
 282static int hfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 283                      struct inode *new_dir, struct dentry *new_dentry)
 284{
 285        int res;
 286
 287        /* Unlink destination if it already exists */
 288        if (new_dentry->d_inode) {
 289                res = hfs_remove(new_dir, new_dentry);
 290                if (res)
 291                        return res;
 292        }
 293
 294        res = hfs_cat_move(old_dentry->d_inode->i_ino,
 295                           old_dir, &old_dentry->d_name,
 296                           new_dir, &new_dentry->d_name);
 297        if (!res)
 298                hfs_cat_build_key(old_dir->i_sb,
 299                                  (btree_key *)&HFS_I(old_dentry->d_inode)->cat_key,
 300                                  new_dir->i_ino, &new_dentry->d_name);
 301        return res;
 302}
 303
 304const struct file_operations hfs_dir_operations = {
 305        .read           = generic_read_dir,
 306        .iterate        = hfs_readdir,
 307        .llseek         = generic_file_llseek,
 308        .release        = hfs_dir_release,
 309};
 310
 311const struct inode_operations hfs_dir_inode_operations = {
 312        .create         = hfs_create,
 313        .lookup         = hfs_lookup,
 314        .unlink         = hfs_remove,
 315        .mkdir          = hfs_mkdir,
 316        .rmdir          = hfs_remove,
 317        .rename         = hfs_rename,
 318        .setattr        = hfs_inode_setattr,
 319};
 320
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