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/fs/hfs/dir.c

https://bitbucket.org/cyanogenmod/android_kernel_asus_tf300t
C | 316 lines | 225 code | 25 blank | 66 comment | 46 complexity | 381fdbb762b527e372fcedf92c7e29ed MD5 | raw file
Possible License(s): LGPL-2.0, AGPL-1.0, GPL-2.0
  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				 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);
 44done:
 45	d_add(dentry, inode);
 46	return NULL;
 47}
 48
 49/*
 50 * hfs_readdir
 51 */
 52static 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));
166out:
167	hfs_find_exit(&fd);
168	return err;
169}
170
171static 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 */
189static 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 */
219static 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 */
251static 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 */
279static 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
301const 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
308const 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};