[linux.git] / fs / exofs / namei.c

/*
 * Copyright (C) 2005, 2006
 * Avishay Traeger ([email protected])
 * Copyright (C) 2008, 2009
 * Boaz Harrosh <[email protected]>
 *
 * Copyrights for code taken from ext2:
 *     Copyright (C) 1992, 1993, 1994, 1995
 *     Remy Card ([email protected])
 *     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,
				   unsigned int flags)
{
	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 = ino ? exofs_iget(dir->i_sb, ino) : NULL;
	return d_splice_alias(inode, dentry);
}

static int exofs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
			 bool excl)
{
	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, umode_t mode,
		       dev_t rdev)
{
	struct inode *inode;
	int err;

	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 = &page_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 = &simple_symlink_inode_operations;
		inode->i_link = (char *)oi->i_data;
		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 = d_inode(old_dentry);

	inode->i_ctime = CURRENT_TIME;
	inode_inc_link_count(inode);
	ihold(inode);

	return exofs_add_nondir(dentry, inode);
}

static int exofs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
	struct inode *inode;
	int err;

	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 = d_inode(dentry);
	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 = d_inode(dentry);
	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 = d_inode(old_dentry);
	struct inode *new_inode = d_inode(new_dentry);
	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;
		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 {
		err = exofs_add_link(new_dentry, old_inode);
		if (err)
			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);
	mark_inode_dirty(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 ([email protected])
e6af00f1	4	* Copyright (C) 2008, 2009
aa281ac6	5	* Boaz Harrosh <[email protected]>
e6af00f1 BH	6	*
	7	* Copyrights for code taken from ext2:
	8	* Copyright (C) 1992, 1993, 1994, 1995
	9	* Remy Card ([email protected])
	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,
00cd8dd3	49	unsigned int flags)
e6af00f1 BH	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);
a9049376	58	inode = ino ? exofs_iget(dir->i_sb, ino) : NULL;
e6af00f1 BH	59	return d_splice_alias(inode, dentry);
	60	}
	61
4acdaf27	62	static int exofs_create(struct inode dir, struct dentry dentry, umode_t mode,
ebfc3b49	63	bool excl)
e6af00f1 BH	64	{
	65	struct inode *inode = exofs_new_inode(dir, mode);
	66	int err = PTR_ERR(inode);
	67	if (!IS_ERR(inode)) {
	68	inode->i_op = &exofs_file_inode_operations;
	69	inode->i_fop = &exofs_file_operations;
	70	inode->i_mapping->a_ops = &exofs_aops;
	71	mark_inode_dirty(inode);
	72	err = exofs_add_nondir(dentry, inode);
	73	}
	74	return err;
	75	}
	76
1a67aafb	77	static int exofs_mknod(struct inode dir, struct dentry dentry, umode_t mode,
e6af00f1 BH	78	dev_t rdev)
	79	{
	80	struct inode *inode;
	81	int err;
	82
e6af00f1 BH	83	inode = exofs_new_inode(dir, mode);
	84	err = PTR_ERR(inode);
	85	if (!IS_ERR(inode)) {
	86	init_special_inode(inode, inode->i_mode, rdev);
	87	mark_inode_dirty(inode);
	88	err = exofs_add_nondir(dentry, inode);
	89	}
	90	return err;
	91	}
	92
	93	static int exofs_symlink(struct inode dir, struct dentry dentry,
	94	const char *symname)
	95	{
	96	struct super_block *sb = dir->i_sb;
	97	int err = -ENAMETOOLONG;
	98	unsigned l = strlen(symname)+1;
	99	struct inode *inode;
	100	struct exofs_i_info *oi;
	101
	102	if (l > sb->s_blocksize)
	103	goto out;
	104
	105	inode = exofs_new_inode(dir, S_IFLNK \| S_IRWXUGO);
	106	err = PTR_ERR(inode);
	107	if (IS_ERR(inode))
	108	goto out;
	109
	110	oi = exofs_i(inode);
	111	if (l > sizeof(oi->i_data)) {
	112	/* slow symlink */
a5ef103d	113	inode->i_op = &page_symlink_inode_operations;
e6af00f1 BH	114	inode->i_mapping->a_ops = &exofs_aops;
	115	memset(oi->i_data, 0, sizeof(oi->i_data));
	116
	117	err = page_symlink(inode, symname, l);
	118	if (err)
	119	goto out_fail;
	120	} else {
	121	/* fast symlink */
a5ef103d AV	122	inode->i_op = &simple_symlink_inode_operations;
a5ef103d AV	123	inode->i_link = (char *)oi->i_data;
e6af00f1 BH	124	memcpy(oi->i_data, symname, l);
	125	inode->i_size = l-1;
	126	}
	127	mark_inode_dirty(inode);
	128
	129	err = exofs_add_nondir(dentry, inode);
	130	out:
	131	return err;
	132
	133	out_fail:
	134	inode_dec_link_count(inode);
	135	iput(inode);
	136	goto out;
	137	}
	138
	139	static int exofs_link(struct dentry old_dentry, struct inode dir,
	140	struct dentry *dentry)
	141	{
2b0143b5	142	struct inode *inode = d_inode(old_dentry);
e6af00f1	143
e6af00f1 BH	144	inode->i_ctime = CURRENT_TIME;
e6af00f1 BH	145	inode_inc_link_count(inode);
7de9c6ee	146	ihold(inode);
e6af00f1 BH	147
	148	return exofs_add_nondir(dentry, inode);
	149	}
	150
18bb1db3	151	static int exofs_mkdir(struct inode dir, struct dentry dentry, umode_t mode)
e6af00f1 BH	152	{
e6af00f1 BH	153	struct inode *inode;
8de52778	154	int err;
e6af00f1 BH	155
	156	inode_inc_link_count(dir);
	157
	158	inode = exofs_new_inode(dir, S_IFDIR \| mode);
	159	err = PTR_ERR(inode);
	160	if (IS_ERR(inode))
	161	goto out_dir;
	162
	163	inode->i_op = &exofs_dir_inode_operations;
	164	inode->i_fop = &exofs_dir_operations;
	165	inode->i_mapping->a_ops = &exofs_aops;
	166
	167	inode_inc_link_count(inode);
	168
	169	err = exofs_make_empty(inode, dir);
	170	if (err)
	171	goto out_fail;
	172
	173	err = exofs_add_link(dentry, inode);
	174	if (err)
	175	goto out_fail;
	176
	177	d_instantiate(dentry, inode);
	178	out:
	179	return err;
	180
	181	out_fail:
	182	inode_dec_link_count(inode);
	183	inode_dec_link_count(inode);
	184	iput(inode);
	185	out_dir:
	186	inode_dec_link_count(dir);
	187	goto out;
	188	}
	189
	190	static int exofs_unlink(struct inode dir, struct dentry dentry)
	191	{
2b0143b5	192	struct inode *inode = d_inode(dentry);
e6af00f1 BH	193	struct exofs_dir_entry *de;
	194	struct page *page;
	195	int err = -ENOENT;
	196
	197	de = exofs_find_entry(dir, dentry, &page);
	198	if (!de)
	199	goto out;
	200
	201	err = exofs_delete_entry(de, page);
	202	if (err)
	203	goto out;
	204
	205	inode->i_ctime = dir->i_ctime;
	206	inode_dec_link_count(inode);
	207	err = 0;
	208	out:
	209	return err;
	210	}
	211
	212	static int exofs_rmdir(struct inode dir, struct dentry dentry)
	213	{
2b0143b5	214	struct inode *inode = d_inode(dentry);
e6af00f1 BH	215	int err = -ENOTEMPTY;
	216
	217	if (exofs_empty_dir(inode)) {
	218	err = exofs_unlink(dir, dentry);
	219	if (!err) {
	220	inode->i_size = 0;
	221	inode_dec_link_count(inode);
	222	inode_dec_link_count(dir);
	223	}
	224	}
	225	return err;
	226	}
	227
	228	static int exofs_rename(struct inode old_dir, struct dentry old_dentry,
	229	struct inode new_dir, struct dentry new_dentry)
	230	{
2b0143b5 DH	231	struct inode *old_inode = d_inode(old_dentry);
2b0143b5 DH	232	struct inode *new_inode = d_inode(new_dentry);
e6af00f1 BH	233	struct page *dir_page = NULL;
	234	struct exofs_dir_entry *dir_de = NULL;
	235	struct page *old_page;
	236	struct exofs_dir_entry *old_de;
	237	int err = -ENOENT;
	238
	239	old_de = exofs_find_entry(old_dir, old_dentry, &old_page);
	240	if (!old_de)
	241	goto out;
	242
	243	if (S_ISDIR(old_inode->i_mode)) {
	244	err = -EIO;
	245	dir_de = exofs_dotdot(old_inode, &dir_page);
	246	if (!dir_de)
	247	goto out_old;
	248	}
	249
	250	if (new_inode) {
	251	struct page *new_page;
	252	struct exofs_dir_entry *new_de;
	253
	254	err = -ENOTEMPTY;
	255	if (dir_de && !exofs_empty_dir(new_inode))
	256	goto out_dir;
	257
	258	err = -ENOENT;
	259	new_de = exofs_find_entry(new_dir, new_dentry, &new_page);
	260	if (!new_de)
	261	goto out_dir;
e6af00f1 BH	262	err = exofs_set_link(new_dir, new_de, new_page, old_inode);
	263	new_inode->i_ctime = CURRENT_TIME;
	264	if (dir_de)
	265	drop_nlink(new_inode);
	266	inode_dec_link_count(new_inode);
	267	if (err)
	268	goto out_dir;
	269	} else {
e6af00f1	270	err = exofs_add_link(new_dentry, old_inode);
babfe560	271	if (err)
e6af00f1	272	goto out_dir;
e6af00f1 BH	273	if (dir_de)
	274	inode_inc_link_count(new_dir);
	275	}
	276
	277	old_inode->i_ctime = CURRENT_TIME;
	278
	279	exofs_delete_entry(old_de, old_page);
babfe560	280	mark_inode_dirty(old_inode);
e6af00f1 BH	281
	282	if (dir_de) {
	283	err = exofs_set_link(old_inode, dir_de, dir_page, new_dir);
	284	inode_dec_link_count(old_dir);
	285	if (err)
	286	goto out_dir;
	287	}
	288	return 0;
	289
	290
	291	out_dir:
	292	if (dir_de) {
	293	kunmap(dir_page);
	294	page_cache_release(dir_page);
	295	}
	296	out_old:
	297	kunmap(old_page);
	298	page_cache_release(old_page);
	299	out:
	300	return err;
	301	}
	302
	303	const struct inode_operations exofs_dir_inode_operations = {
	304	.create = exofs_create,
	305	.lookup = exofs_lookup,
	306	.link = exofs_link,
	307	.unlink = exofs_unlink,
	308	.symlink = exofs_symlink,
	309	.mkdir = exofs_mkdir,
	310	.rmdir = exofs_rmdir,
	311	.mknod = exofs_mknod,
	312	.rename = exofs_rename,
	313	.setattr = exofs_setattr,
	314	};
	315
	316	const struct inode_operations exofs_special_inode_operations = {
	317	.setattr = exofs_setattr,
	318	};