[net-next-2.6.git] / fs / exofs / namei.c

/*
 * Copyright (C) 2005, 2006
 * Avishay Traeger (avishay@gmail.com)
 * Copyright (C) 2008, 2009
 * Boaz Harrosh <bharrosh@panasas.com>
 *
 * Copyrights for code taken from ext2:
 *     Copyright (C) 1992, 1993, 1994, 1995
 *     Remy Card (card@masi.ibp.fr)
 *     Laboratoire MASI - Institut Blaise Pascal
 *     Universite Pierre et Marie Curie (Paris VI)
 *     from
 *     linux/fs/minix/inode.c
 *     Copyright (C) 1991, 1992  Linus Torvalds
 *
 * This file is part of exofs.
 *
 * exofs is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation.  Since it is based on ext2, and the only
 * valid version of GPL for the Linux kernel is version 2, the only valid
 * version of GPL for exofs is version 2.
 *
 * exofs is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with exofs; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "exofs.h"

static inline int exofs_add_nondir(struct dentry *dentry, struct inode *inode)
{
	int err = exofs_add_link(dentry, inode);
	if (!err) {
		d_instantiate(dentry, inode);
		return 0;
	}
	inode_dec_link_count(inode);
	iput(inode);
	return err;
}

static struct dentry *exofs_lookup(struct inode *dir, struct dentry *dentry,
				   struct nameidata *nd)
{
	struct inode *inode;
	ino_t ino;

	if (dentry->d_name.len > EXOFS_NAME_LEN)
		return ERR_PTR(-ENAMETOOLONG);

	ino = exofs_inode_by_name(dir, dentry);
	inode = NULL;
	if (ino) {
		inode = exofs_iget(dir->i_sb, ino);
		if (IS_ERR(inode))
			return ERR_CAST(inode);
	}
	return d_splice_alias(inode, dentry);
}

static int exofs_create(struct inode *dir, struct dentry *dentry, int mode,
			 struct nameidata *nd)
{
	struct inode *inode = exofs_new_inode(dir, mode);
	int err = PTR_ERR(inode);
	if (!IS_ERR(inode)) {
		inode->i_op = &exofs_file_inode_operations;
		inode->i_fop = &exofs_file_operations;
		inode->i_mapping->a_ops = &exofs_aops;
		mark_inode_dirty(inode);
		err = exofs_add_nondir(dentry, inode);
	}
	return err;
}

static int exofs_mknod(struct inode *dir, struct dentry *dentry, int mode,
		       dev_t rdev)
{
	struct inode *inode;
	int err;

	if (!new_valid_dev(rdev))
		return -EINVAL;

	inode = exofs_new_inode(dir, mode);
	err = PTR_ERR(inode);
	if (!IS_ERR(inode)) {
		init_special_inode(inode, inode->i_mode, rdev);
		mark_inode_dirty(inode);
		err = exofs_add_nondir(dentry, inode);
	}
	return err;
}

static int exofs_symlink(struct inode *dir, struct dentry *dentry,
			  const char *symname)
{
	struct super_block *sb = dir->i_sb;
	int err = -ENAMETOOLONG;
	unsigned l = strlen(symname)+1;
	struct inode *inode;
	struct exofs_i_info *oi;

	if (l > sb->s_blocksize)
		goto out;

	inode = exofs_new_inode(dir, S_IFLNK | S_IRWXUGO);
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out;

	oi = exofs_i(inode);
	if (l > sizeof(oi->i_data)) {
		/* slow symlink */
		inode->i_op = &exofs_symlink_inode_operations;
		inode->i_mapping->a_ops = &exofs_aops;
		memset(oi->i_data, 0, sizeof(oi->i_data));

		err = page_symlink(inode, symname, l);
		if (err)
			goto out_fail;
	} else {
		/* fast symlink */
		inode->i_op = &exofs_fast_symlink_inode_operations;
		memcpy(oi->i_data, symname, l);
		inode->i_size = l-1;
	}
	mark_inode_dirty(inode);

	err = exofs_add_nondir(dentry, inode);
out:
	return err;

out_fail:
	inode_dec_link_count(inode);
	iput(inode);
	goto out;
}

static int exofs_link(struct dentry *old_dentry, struct inode *dir,
		struct dentry *dentry)
{
	struct inode *inode = old_dentry->d_inode;

	if (inode->i_nlink >= EXOFS_LINK_MAX)
		return -EMLINK;

	inode->i_ctime = CURRENT_TIME;
	inode_inc_link_count(inode);
	atomic_inc(&inode->i_count);

	return exofs_add_nondir(dentry, inode);
}

static int exofs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
	struct inode *inode;
	int err = -EMLINK;

	if (dir->i_nlink >= EXOFS_LINK_MAX)
		goto out;

	inode_inc_link_count(dir);

	inode = exofs_new_inode(dir, S_IFDIR | mode);
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out_dir;

	inode->i_op = &exofs_dir_inode_operations;
	inode->i_fop = &exofs_dir_operations;
	inode->i_mapping->a_ops = &exofs_aops;

	inode_inc_link_count(inode);

	err = exofs_make_empty(inode, dir);
	if (err)
		goto out_fail;

	err = exofs_add_link(dentry, inode);
	if (err)
		goto out_fail;

	d_instantiate(dentry, inode);
out:
	return err;

out_fail:
	inode_dec_link_count(inode);
	inode_dec_link_count(inode);
	iput(inode);
out_dir:
	inode_dec_link_count(dir);
	goto out;
}

static int exofs_unlink(struct inode *dir, struct dentry *dentry)
{
	struct inode *inode = dentry->d_inode;
	struct exofs_dir_entry *de;
	struct page *page;
	int err = -ENOENT;

	de = exofs_find_entry(dir, dentry, &page);
	if (!de)
		goto out;

	err = exofs_delete_entry(de, page);
	if (err)
		goto out;

	inode->i_ctime = dir->i_ctime;
	inode_dec_link_count(inode);
	err = 0;
out:
	return err;
}

static int exofs_rmdir(struct inode *dir, struct dentry *dentry)
{
	struct inode *inode = dentry->d_inode;
	int err = -ENOTEMPTY;

	if (exofs_empty_dir(inode)) {
		err = exofs_unlink(dir, dentry);
		if (!err) {
			inode->i_size = 0;
			inode_dec_link_count(inode);
			inode_dec_link_count(dir);
		}
	}
	return err;
}

static int exofs_rename(struct inode *old_dir, struct dentry *old_dentry,
		struct inode *new_dir, struct dentry *new_dentry)
{
	struct inode *old_inode = old_dentry->d_inode;
	struct inode *new_inode = new_dentry->d_inode;
	struct page *dir_page = NULL;
	struct exofs_dir_entry *dir_de = NULL;
	struct page *old_page;
	struct exofs_dir_entry *old_de;
	int err = -ENOENT;

	old_de = exofs_find_entry(old_dir, old_dentry, &old_page);
	if (!old_de)
		goto out;

	if (S_ISDIR(old_inode->i_mode)) {
		err = -EIO;
		dir_de = exofs_dotdot(old_inode, &dir_page);
		if (!dir_de)
			goto out_old;
	}

	if (new_inode) {
		struct page *new_page;
		struct exofs_dir_entry *new_de;

		err = -ENOTEMPTY;
		if (dir_de && !exofs_empty_dir(new_inode))
			goto out_dir;

		err = -ENOENT;
		new_de = exofs_find_entry(new_dir, new_dentry, &new_page);
		if (!new_de)
			goto out_dir;
		inode_inc_link_count(old_inode);
		err = exofs_set_link(new_dir, new_de, new_page, old_inode);
		new_inode->i_ctime = CURRENT_TIME;
		if (dir_de)
			drop_nlink(new_inode);
		inode_dec_link_count(new_inode);
		if (err)
			goto out_dir;
	} else {
		if (dir_de) {
			err = -EMLINK;
			if (new_dir->i_nlink >= EXOFS_LINK_MAX)
				goto out_dir;
		}
		inode_inc_link_count(old_inode);
		err = exofs_add_link(new_dentry, old_inode);
		if (err) {
			inode_dec_link_count(old_inode);
			goto out_dir;
		}
		if (dir_de)
			inode_inc_link_count(new_dir);
	}

	old_inode->i_ctime = CURRENT_TIME;

	exofs_delete_entry(old_de, old_page);
	inode_dec_link_count(old_inode);

	if (dir_de) {
		err = exofs_set_link(old_inode, dir_de, dir_page, new_dir);
		inode_dec_link_count(old_dir);
		if (err)
			goto out_dir;
	}
	return 0;


out_dir:
	if (dir_de) {
		kunmap(dir_page);
		page_cache_release(dir_page);
	}
out_old:
	kunmap(old_page);
	page_cache_release(old_page);
out:
	return err;
}

const struct inode_operations exofs_dir_inode_operations = {
	.create 	= exofs_create,
	.lookup 	= exofs_lookup,
	.link   	= exofs_link,
	.unlink 	= exofs_unlink,
	.symlink	= exofs_symlink,
	.mkdir  	= exofs_mkdir,
	.rmdir  	= exofs_rmdir,
	.mknod  	= exofs_mknod,
	.rename 	= exofs_rename,
	.setattr	= exofs_setattr,
};

const struct inode_operations exofs_special_inode_operations = {
	.setattr	= exofs_setattr,
};
Commit	Line	Data
e6af00f1 BH	1	/*
e6af00f1 BH	2	* Copyright (C) 2005, 2006
27d2e149	3	* Avishay Traeger (avishay@gmail.com)
e6af00f1 BH	4	* Copyright (C) 2008, 2009
	5	* Boaz Harrosh <bharrosh@panasas.com>
	6	*
	7	* Copyrights for code taken from ext2:
	8	* Copyright (C) 1992, 1993, 1994, 1995
	9	* Remy Card (card@masi.ibp.fr)
	10	* Laboratoire MASI - Institut Blaise Pascal
	11	* Universite Pierre et Marie Curie (Paris VI)
	12	* from
	13	* linux/fs/minix/inode.c
	14	* Copyright (C) 1991, 1992 Linus Torvalds
	15	*
	16	* This file is part of exofs.
	17	*
	18	* exofs is free software; you can redistribute it and/or modify
	19	* it under the terms of the GNU General Public License as published by
	20	* the Free Software Foundation. Since it is based on ext2, and the only
	21	* valid version of GPL for the Linux kernel is version 2, the only valid
	22	* version of GPL for exofs is version 2.
	23	*
	24	* exofs is distributed in the hope that it will be useful,
	25	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	26	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	27	* GNU General Public License for more details.
	28	*
	29	* You should have received a copy of the GNU General Public License
	30	* along with exofs; if not, write to the Free Software
	31	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	32	*/
	33
	34	#include "exofs.h"
	35
	36	static inline int exofs_add_nondir(struct dentry dentry, struct inode inode)
	37	{
	38	int err = exofs_add_link(dentry, inode);
	39	if (!err) {
	40	d_instantiate(dentry, inode);
	41	return 0;
	42	}
	43	inode_dec_link_count(inode);
	44	iput(inode);
	45	return err;
	46	}
	47
	48	static struct dentry exofs_lookup(struct inode dir, struct dentry *dentry,
	49	struct nameidata *nd)
	50	{
	51	struct inode *inode;
	52	ino_t ino;
	53
	54	if (dentry->d_name.len > EXOFS_NAME_LEN)
	55	return ERR_PTR(-ENAMETOOLONG);
	56
	57	ino = exofs_inode_by_name(dir, dentry);
	58	inode = NULL;
	59	if (ino) {
	60	inode = exofs_iget(dir->i_sb, ino);
	61	if (IS_ERR(inode))
	62	return ERR_CAST(inode);
	63	}
	64	return d_splice_alias(inode, dentry);
	65	}
	66
	67	static int exofs_create(struct inode dir, struct dentry dentry, int mode,
68	struct nameidata *nd)
69	{
70	struct inode *inode = exofs_new_inode(dir, mode);
71	int err = PTR_ERR(inode);
72	if (!IS_ERR(inode)) {
73	inode->i_op = &exofs_file_inode_operations;
74	inode->i_fop = &exofs_file_operations;
75	inode->i_mapping->a_ops = &exofs_aops;
76	mark_inode_dirty(inode);
77	err = exofs_add_nondir(dentry, inode);
78	}
79	return err;
80	}
81
82	static int exofs_mknod(struct inode dir, struct dentry dentry, int mode,
83	dev_t rdev)
84	{
85	struct inode *inode;
86	int err;
87
88	if (!new_valid_dev(rdev))
89	return -EINVAL;
90
91	inode = exofs_new_inode(dir, mode);
92	err = PTR_ERR(inode);
93	if (!IS_ERR(inode)) {
94	init_special_inode(inode, inode->i_mode, rdev);
95	mark_inode_dirty(inode);
96	err = exofs_add_nondir(dentry, inode);
97	}
98	return err;
99	}
100
101	static int exofs_symlink(struct inode dir, struct dentry dentry,
102	const char *symname)
103	{
104	struct super_block *sb = dir->i_sb;
105	int err = -ENAMETOOLONG;
106	unsigned l = strlen(symname)+1;
107	struct inode *inode;
108	struct exofs_i_info *oi;
109
110	if (l > sb->s_blocksize)
111	goto out;
112
113	inode = exofs_new_inode(dir, S_IFLNK \| S_IRWXUGO);
114	err = PTR_ERR(inode);
115	if (IS_ERR(inode))
116	goto out;
117
118	oi = exofs_i(inode);
119	if (l > sizeof(oi->i_data)) {
120	/* slow symlink */
121	inode->i_op = &exofs_symlink_inode_operations;
122	inode->i_mapping->a_ops = &exofs_aops;
123	memset(oi->i_data, 0, sizeof(oi->i_data));
124
125	err = page_symlink(inode, symname, l);
126	if (err)
127	goto out_fail;
128	} else {
129	/* fast symlink */
130	inode->i_op = &exofs_fast_symlink_inode_operations;
131	memcpy(oi->i_data, symname, l);
132	inode->i_size = l-1;
133	}
134	mark_inode_dirty(inode);
135
136	err = exofs_add_nondir(dentry, inode);
137	out:
138	return err;
139
140	out_fail:
141	inode_dec_link_count(inode);
142	iput(inode);
143	goto out;
144	}
145
146	static int exofs_link(struct dentry old_dentry, struct inode dir,
147	struct dentry *dentry)
148	{
149	struct inode *inode = old_dentry->d_inode;
150
151	if (inode->i_nlink >= EXOFS_LINK_MAX)
152	return -EMLINK;
153
154	inode->i_ctime = CURRENT_TIME;
155	inode_inc_link_count(inode);
156	atomic_inc(&inode->i_count);
157
158	return exofs_add_nondir(dentry, inode);
159	}
160
161	static int exofs_mkdir(struct inode dir, struct dentry dentry, int mode)
162	{
163	struct inode *inode;
164	int err = -EMLINK;
165
166	if (dir->i_nlink >= EXOFS_LINK_MAX)
167	goto out;
168
169	inode_inc_link_count(dir);
170
171	inode = exofs_new_inode(dir, S_IFDIR \| mode);
172	err = PTR_ERR(inode);
173	if (IS_ERR(inode))
174	goto out_dir;
175
176	inode->i_op = &exofs_dir_inode_operations;
177	inode->i_fop = &exofs_dir_operations;
178	inode->i_mapping->a_ops = &exofs_aops;
179
180	inode_inc_link_count(inode);
181
182	err = exofs_make_empty(inode, dir);
183	if (err)
184	goto out_fail;
185
186	err = exofs_add_link(dentry, inode);
187	if (err)
188	goto out_fail;
189
190	d_instantiate(dentry, inode);
191	out:
192	return err;
193
194	out_fail:
195	inode_dec_link_count(inode);
196	inode_dec_link_count(inode);
197	iput(inode);
198	out_dir:
199	inode_dec_link_count(dir);
200	goto out;
201	}
202
203	static int exofs_unlink(struct inode dir, struct dentry dentry)
204	{
205	struct inode *inode = dentry->d_inode;
206	struct exofs_dir_entry *de;
207	struct page *page;
208	int err = -ENOENT;
209
210	de = exofs_find_entry(dir, dentry, &page);
211	if (!de)
212	goto out;
213
214	err = exofs_delete_entry(de, page);
215	if (err)
216	goto out;
217
218	inode->i_ctime = dir->i_ctime;
219	inode_dec_link_count(inode);
220	err = 0;
221	out:
222	return err;
223	}
224
225	static int exofs_rmdir(struct inode dir, struct dentry dentry)
226	{
227	struct inode *inode = dentry->d_inode;
228	int err = -ENOTEMPTY;
229
230	if (exofs_empty_dir(inode)) {
231	err = exofs_unlink(dir, dentry);
232	if (!err) {
233	inode->i_size = 0;
234	inode_dec_link_count(inode);
235	inode_dec_link_count(dir);
236	}
237	}
238	return err;
239	}
240
241	static int exofs_rename(struct inode old_dir, struct dentry old_dentry,
242	struct inode new_dir, struct dentry new_dentry)
243	{
244	struct inode *old_inode = old_dentry->d_inode;
245	struct inode *new_inode = new_dentry->d_inode;
246	struct page *dir_page = NULL;
247	struct exofs_dir_entry *dir_de = NULL;
248	struct page *old_page;
249	struct exofs_dir_entry *old_de;
250	int err = -ENOENT;
251
252	old_de = exofs_find_entry(old_dir, old_dentry, &old_page);
253	if (!old_de)
254	goto out;
255
256	if (S_ISDIR(old_inode->i_mode)) {
257	err = -EIO;
258	dir_de = exofs_dotdot(old_inode, &dir_page);
259	if (!dir_de)
260	goto out_old;
261	}
262
263	if (new_inode) {
264	struct page *new_page;
265	struct exofs_dir_entry *new_de;
266
267	err = -ENOTEMPTY;
268	if (dir_de && !exofs_empty_dir(new_inode))
269	goto out_dir;
270
271	err = -ENOENT;
272	new_de = exofs_find_entry(new_dir, new_dentry, &new_page);
273	if (!new_de)
274	goto out_dir;
275	inode_inc_link_count(old_inode);
276	err = exofs_set_link(new_dir, new_de, new_page, old_inode);
277	new_inode->i_ctime = CURRENT_TIME;
278	if (dir_de)
279	drop_nlink(new_inode);
280	inode_dec_link_count(new_inode);
281	if (err)
282	goto out_dir;
283	} else {
284	if (dir_de) {
285	err = -EMLINK;
286	if (new_dir->i_nlink >= EXOFS_LINK_MAX)
287	goto out_dir;
288	}
289	inode_inc_link_count(old_inode);
290	err = exofs_add_link(new_dentry, old_inode);
291	if (err) {
292	inode_dec_link_count(old_inode);
293	goto out_dir;
294	}
295	if (dir_de)
296	inode_inc_link_count(new_dir);
297	}
298
299	old_inode->i_ctime = CURRENT_TIME;
300
301	exofs_delete_entry(old_de, old_page);
302	inode_dec_link_count(old_inode);
303
304	if (dir_de) {
305	err = exofs_set_link(old_inode, dir_de, dir_page, new_dir);
306	inode_dec_link_count(old_dir);
307	if (err)
308	goto out_dir;
309	}
310	return 0;
311
312
313	out_dir:
314	if (dir_de) {
315	kunmap(dir_page);
316	page_cache_release(dir_page);
317	}
318	out_old:
319	kunmap(old_page);
320	page_cache_release(old_page);
321	out:
322	return err;
323	}
324
325	const struct inode_operations exofs_dir_inode_operations = {
326	.create = exofs_create,
327	.lookup = exofs_lookup,
328	.link = exofs_link,
329	.unlink = exofs_unlink,
330	.symlink = exofs_symlink,
331	.mkdir = exofs_mkdir,
332	.rmdir = exofs_rmdir,
333	.mknod = exofs_mknod,
334	.rename = exofs_rename,
335	.setattr = exofs_setattr,
336	};
337
338	const struct inode_operations exofs_special_inode_operations = {
339	.setattr = exofs_setattr,
340	};