[linux-2.6-block.git] / fs / ext2 / namei.c

// SPDX-License-Identifier: GPL-2.0
/*
 * linux/fs/ext2/namei.c
 *
 * Rewrite to pagecache. Almost all code had been changed, so blame me
 * if the things go wrong. Please, send bug reports to
 * viro@parcelfarce.linux.theplanet.co.uk
 *
 * Stuff here is basically a glue between the VFS and generic UNIXish
 * filesystem that keeps everything in pagecache. All knowledge of the
 * directory layout is in fs/ext2/dir.c - it turned out to be easily separatable
 * and it's easier to debug that way. In principle we might want to
 * generalize that a bit and turn it into a library. Or not.
 *
 * The only non-static object here is ext2_dir_inode_operations.
 *
 * TODO: get rid of kmap() use, add readahead.
 *
 * 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/namei.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  Big-endian to little-endian byte-swapping/bitmaps by
 *        David S. Miller (davem@caip.rutgers.edu), 1995
 */

#include <linux/pagemap.h>
#include <linux/quotaops.h>
#include "ext2.h"
#include "xattr.h"
#include "acl.h"

static inline int ext2_add_nondir(struct dentry *dentry, struct inode *inode)
{
	int err = ext2_add_link(dentry, inode);
	if (!err) {
		unlock_new_inode(inode);
		d_instantiate(dentry, inode);
		return 0;
	}
	inode_dec_link_count(inode);
	unlock_new_inode(inode);
	iput(inode);
	return err;
}

/*
 * Methods themselves.
 */

static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags)
{
	struct inode * inode;
	ino_t ino;
	
	if (dentry->d_name.len > EXT2_NAME_LEN)
		return ERR_PTR(-ENAMETOOLONG);

	ino = ext2_inode_by_name(dir, &dentry->d_name);
	inode = NULL;
	if (ino) {
		inode = ext2_iget(dir->i_sb, ino);
		if (inode == ERR_PTR(-ESTALE)) {
			ext2_error(dir->i_sb, __func__,
					"deleted inode referenced: %lu",
					(unsigned long) ino);
			return ERR_PTR(-EIO);
		}
	}
	return d_splice_alias(inode, dentry);
}

struct dentry *ext2_get_parent(struct dentry *child)
{
	struct qstr dotdot = QSTR_INIT("..", 2);
	unsigned long ino = ext2_inode_by_name(d_inode(child), &dotdot);
	if (!ino)
		return ERR_PTR(-ENOENT);
	return d_obtain_alias(ext2_iget(child->d_sb, ino));
} 

/*
 * By the time this is called, we already have created
 * the directory cache entry for the new file, but it
 * is so far negative - it has no inode.
 *
 * If the create succeeds, we fill in the inode information
 * with d_instantiate(). 
 */
static int ext2_create (struct inode * dir, struct dentry * dentry, umode_t mode, bool excl)
{
	struct inode *inode;
	int err;

	err = dquot_initialize(dir);
	if (err)
		return err;

	inode = ext2_new_inode(dir, mode, &dentry->d_name);
	if (IS_ERR(inode))
		return PTR_ERR(inode);

	inode->i_op = &ext2_file_inode_operations;
	if (test_opt(inode->i_sb, NOBH)) {
		inode->i_mapping->a_ops = &ext2_nobh_aops;
		inode->i_fop = &ext2_file_operations;
	} else {
		inode->i_mapping->a_ops = &ext2_aops;
		inode->i_fop = &ext2_file_operations;
	}
	mark_inode_dirty(inode);
	return ext2_add_nondir(dentry, inode);
}

static int ext2_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
{
	struct inode *inode = ext2_new_inode(dir, mode, NULL);
	if (IS_ERR(inode))
		return PTR_ERR(inode);

	inode->i_op = &ext2_file_inode_operations;
	if (test_opt(inode->i_sb, NOBH)) {
		inode->i_mapping->a_ops = &ext2_nobh_aops;
		inode->i_fop = &ext2_file_operations;
	} else {
		inode->i_mapping->a_ops = &ext2_aops;
		inode->i_fop = &ext2_file_operations;
	}
	mark_inode_dirty(inode);
	d_tmpfile(dentry, inode);
	unlock_new_inode(inode);
	return 0;
}

static int ext2_mknod (struct inode * dir, struct dentry *dentry, umode_t mode, dev_t rdev)
{
	struct inode * inode;
	int err;

	err = dquot_initialize(dir);
	if (err)
		return err;

	inode = ext2_new_inode (dir, mode, &dentry->d_name);
	err = PTR_ERR(inode);
	if (!IS_ERR(inode)) {
		init_special_inode(inode, inode->i_mode, rdev);
#ifdef CONFIG_EXT2_FS_XATTR
		inode->i_op = &ext2_special_inode_operations;
#endif
		mark_inode_dirty(inode);
		err = ext2_add_nondir(dentry, inode);
	}
	return err;
}

static int ext2_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;

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

	err = dquot_initialize(dir);
	if (err)
		goto out;

	inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO, &dentry->d_name);
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out;

	if (l > sizeof (EXT2_I(inode)->i_data)) {
		/* slow symlink */
		inode->i_op = &ext2_symlink_inode_operations;
		inode_nohighmem(inode);
		if (test_opt(inode->i_sb, NOBH))
			inode->i_mapping->a_ops = &ext2_nobh_aops;
		else
			inode->i_mapping->a_ops = &ext2_aops;
		err = page_symlink(inode, symname, l);
		if (err)
			goto out_fail;
	} else {
		/* fast symlink */
		inode->i_op = &ext2_fast_symlink_inode_operations;
		inode->i_link = (char*)EXT2_I(inode)->i_data;
		memcpy(inode->i_link, symname, l);
		inode->i_size = l-1;
	}
	mark_inode_dirty(inode);

	err = ext2_add_nondir(dentry, inode);
out:
	return err;

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

static int ext2_link (struct dentry * old_dentry, struct inode * dir,
	struct dentry *dentry)
{
	struct inode *inode = d_inode(old_dentry);
	int err;

	err = dquot_initialize(dir);
	if (err)
		return err;

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

	err = ext2_add_link(dentry, inode);
	if (!err) {
		d_instantiate(dentry, inode);
		return 0;
	}
	inode_dec_link_count(inode);
	iput(inode);
	return err;
}

static int ext2_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
{
	struct inode * inode;
	int err;

	err = dquot_initialize(dir);
	if (err)
		return err;

	inode_inc_link_count(dir);

	inode = ext2_new_inode(dir, S_IFDIR | mode, &dentry->d_name);
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out_dir;

	inode->i_op = &ext2_dir_inode_operations;
	inode->i_fop = &ext2_dir_operations;
	if (test_opt(inode->i_sb, NOBH))
		inode->i_mapping->a_ops = &ext2_nobh_aops;
	else
		inode->i_mapping->a_ops = &ext2_aops;

	inode_inc_link_count(inode);

	err = ext2_make_empty(inode, dir);
	if (err)
		goto out_fail;

	err = ext2_add_link(dentry, inode);
	if (err)
		goto out_fail;

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

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

static int ext2_unlink(struct inode * dir, struct dentry *dentry)
{
	struct inode * inode = d_inode(dentry);
	struct ext2_dir_entry_2 * de;
	struct page * page;
	int err;

	err = dquot_initialize(dir);
	if (err)
		goto out;

	de = ext2_find_entry (dir, &dentry->d_name, &page);
	if (!de) {
		err = -ENOENT;
		goto out;
	}

	err = ext2_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 ext2_rmdir (struct inode * dir, struct dentry *dentry)
{
	struct inode * inode = d_inode(dentry);
	int err = -ENOTEMPTY;

	if (ext2_empty_dir(inode)) {
		err = ext2_unlink(dir, dentry);
		if (!err) {
			inode->i_size = 0;
			inode_dec_link_count(inode);
			inode_dec_link_count(dir);
		}
	}
	return err;
}

static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
			struct inode * new_dir,	struct dentry * new_dentry,
			unsigned int flags)
{
	struct inode * old_inode = d_inode(old_dentry);
	struct inode * new_inode = d_inode(new_dentry);
	struct page * dir_page = NULL;
	struct ext2_dir_entry_2 * dir_de = NULL;
	struct page * old_page;
	struct ext2_dir_entry_2 * old_de;
	int err;

	if (flags & ~RENAME_NOREPLACE)
		return -EINVAL;

	err = dquot_initialize(old_dir);
	if (err)
		goto out;

	err = dquot_initialize(new_dir);
	if (err)
		goto out;

	old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page);
	if (!old_de) {
		err = -ENOENT;
		goto out;
	}

	if (S_ISDIR(old_inode->i_mode)) {
		err = -EIO;
		dir_de = ext2_dotdot(old_inode, &dir_page);
		if (!dir_de)
			goto out_old;
	}

	if (new_inode) {
		struct page *new_page;
		struct ext2_dir_entry_2 *new_de;

		err = -ENOTEMPTY;
		if (dir_de && !ext2_empty_dir (new_inode))
			goto out_dir;

		err = -ENOENT;
		new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page);
		if (!new_de)
			goto out_dir;
		ext2_set_link(new_dir, new_de, new_page, old_inode, 1);
		new_inode->i_ctime = current_time(new_inode);
		if (dir_de)
			drop_nlink(new_inode);
		inode_dec_link_count(new_inode);
	} else {
		err = ext2_add_link(new_dentry, old_inode);
		if (err)
			goto out_dir;
		if (dir_de)
			inode_inc_link_count(new_dir);
	}

	/*
	 * Like most other Unix systems, set the ctime for inodes on a
 	 * rename.
	 */
	old_inode->i_ctime = current_time(old_inode);
	mark_inode_dirty(old_inode);

	ext2_delete_entry (old_de, old_page);

	if (dir_de) {
		if (old_dir != new_dir)
			ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0);
		else {
			kunmap(dir_page);
			put_page(dir_page);
		}
		inode_dec_link_count(old_dir);
	}
	return 0;


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

const struct inode_operations ext2_dir_inode_operations = {
	.create		= ext2_create,
	.lookup		= ext2_lookup,
	.link		= ext2_link,
	.unlink		= ext2_unlink,
	.symlink	= ext2_symlink,
	.mkdir		= ext2_mkdir,
	.rmdir		= ext2_rmdir,
	.mknod		= ext2_mknod,
	.rename		= ext2_rename,
#ifdef CONFIG_EXT2_FS_XATTR
	.listxattr	= ext2_listxattr,
#endif
	.setattr	= ext2_setattr,
	.get_acl	= ext2_get_acl,
	.set_acl	= ext2_set_acl,
	.tmpfile	= ext2_tmpfile,
};

const struct inode_operations ext2_special_inode_operations = {
#ifdef CONFIG_EXT2_FS_XATTR
	.listxattr	= ext2_listxattr,
#endif
	.setattr	= ext2_setattr,
	.get_acl	= ext2_get_acl,
	.set_acl	= ext2_set_acl,
};
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* linux/fs/ext2/namei.c
	4	*
	5	* Rewrite to pagecache. Almost all code had been changed, so blame me
	6	* if the things go wrong. Please, send bug reports to
	7	* viro@parcelfarce.linux.theplanet.co.uk
	8	*
	9	* Stuff here is basically a glue between the VFS and generic UNIXish
	10	* filesystem that keeps everything in pagecache. All knowledge of the
	11	* directory layout is in fs/ext2/dir.c - it turned out to be easily separatable
	12	* and it's easier to debug that way. In principle we might want to
	13	* generalize that a bit and turn it into a library. Or not.
	14	*
	15	* The only non-static object here is ext2_dir_inode_operations.
	16	*
	17	* TODO: get rid of kmap() use, add readahead.
	18	*
	19	* Copyright (C) 1992, 1993, 1994, 1995
	20	* Remy Card (card@masi.ibp.fr)
	21	* Laboratoire MASI - Institut Blaise Pascal
	22	* Universite Pierre et Marie Curie (Paris VI)
	23	*
	24	* from
	25	*
	26	* linux/fs/minix/namei.c
	27	*
	28	* Copyright (C) 1991, 1992 Linus Torvalds
	29	*
	30	* Big-endian to little-endian byte-swapping/bitmaps by
	31	* David S. Miller (davem@caip.rutgers.edu), 1995
	32	*/
	33
	34	#include <linux/pagemap.h>
	35	#include <linux/quotaops.h>
	36	#include "ext2.h"
	37	#include "xattr.h"
	38	#include "acl.h"
	39
	40	static inline int ext2_add_nondir(struct dentry dentry, struct inode inode)
	41	{
	42	int err = ext2_add_link(dentry, inode);
	43	if (!err) {
	44	unlock_new_inode(inode);
	45	d_instantiate(dentry, inode);
	46	return 0;
	47	}
	48	inode_dec_link_count(inode);
	49	unlock_new_inode(inode);
	50	iput(inode);
	51	return err;
	52	}
	53
	54	/*
	55	* Methods themselves.
	56	*/
	57
	58	static struct dentry ext2_lookup(struct inode dir, struct dentry *dentry, unsigned int flags)
	59	{
	60	struct inode * inode;
	61	ino_t ino;
	62
	63	if (dentry->d_name.len > EXT2_NAME_LEN)
	64	return ERR_PTR(-ENAMETOOLONG);
	65
	66	ino = ext2_inode_by_name(dir, &dentry->d_name);
	67	inode = NULL;
	68	if (ino) {
	69	inode = ext2_iget(dir->i_sb, ino);
	70	if (inode == ERR_PTR(-ESTALE)) {
	71	ext2_error(dir->i_sb, __func__,
	72	"deleted inode referenced: %lu",
	73	(unsigned long) ino);
	74	return ERR_PTR(-EIO);
	75	}
	76	}
	77	return d_splice_alias(inode, dentry);
	78	}
	79
	80	struct dentry ext2_get_parent(struct dentry child)
	81	{
	82	struct qstr dotdot = QSTR_INIT("..", 2);
	83	unsigned long ino = ext2_inode_by_name(d_inode(child), &dotdot);
	84	if (!ino)
	85	return ERR_PTR(-ENOENT);
	86	return d_obtain_alias(ext2_iget(child->d_sb, ino));
	87	}
	88
	89	/*
	90	* By the time this is called, we already have created
	91	* the directory cache entry for the new file, but it
	92	* is so far negative - it has no inode.
	93	*
	94	* If the create succeeds, we fill in the inode information
	95	* with d_instantiate().
	96	*/
	97	static int ext2_create (struct inode * dir, struct dentry * dentry, umode_t mode, bool excl)
	98	{
	99	struct inode *inode;
	100	int err;
	101
	102	err = dquot_initialize(dir);
	103	if (err)
	104	return err;
	105
	106	inode = ext2_new_inode(dir, mode, &dentry->d_name);
	107	if (IS_ERR(inode))
	108	return PTR_ERR(inode);
	109
	110	inode->i_op = &ext2_file_inode_operations;
	111	if (test_opt(inode->i_sb, NOBH)) {
	112	inode->i_mapping->a_ops = &ext2_nobh_aops;
	113	inode->i_fop = &ext2_file_operations;
	114	} else {
	115	inode->i_mapping->a_ops = &ext2_aops;
	116	inode->i_fop = &ext2_file_operations;
	117	}
	118	mark_inode_dirty(inode);
	119	return ext2_add_nondir(dentry, inode);
	120	}
	121
	122	static int ext2_tmpfile(struct inode dir, struct dentry dentry, umode_t mode)
	123	{
	124	struct inode *inode = ext2_new_inode(dir, mode, NULL);
	125	if (IS_ERR(inode))
	126	return PTR_ERR(inode);
	127
	128	inode->i_op = &ext2_file_inode_operations;
	129	if (test_opt(inode->i_sb, NOBH)) {
	130	inode->i_mapping->a_ops = &ext2_nobh_aops;
	131	inode->i_fop = &ext2_file_operations;
	132	} else {
	133	inode->i_mapping->a_ops = &ext2_aops;
	134	inode->i_fop = &ext2_file_operations;
	135	}
	136	mark_inode_dirty(inode);
	137	d_tmpfile(dentry, inode);
	138	unlock_new_inode(inode);
	139	return 0;
	140	}
	141
	142	static int ext2_mknod (struct inode * dir, struct dentry *dentry, umode_t mode, dev_t rdev)
	143	{
	144	struct inode * inode;
	145	int err;
	146
	147	err = dquot_initialize(dir);
	148	if (err)
	149	return err;
	150
	151	inode = ext2_new_inode (dir, mode, &dentry->d_name);
	152	err = PTR_ERR(inode);
	153	if (!IS_ERR(inode)) {
	154	init_special_inode(inode, inode->i_mode, rdev);
	155	#ifdef CONFIG_EXT2_FS_XATTR
	156	inode->i_op = &ext2_special_inode_operations;
	157	#endif
	158	mark_inode_dirty(inode);
	159	err = ext2_add_nondir(dentry, inode);
	160	}
	161	return err;
	162	}
	163
	164	static int ext2_symlink (struct inode * dir, struct dentry * dentry,
	165	const char * symname)
	166	{
	167	struct super_block * sb = dir->i_sb;
	168	int err = -ENAMETOOLONG;
	169	unsigned l = strlen(symname)+1;
	170	struct inode * inode;
	171
	172	if (l > sb->s_blocksize)
	173	goto out;
	174
	175	err = dquot_initialize(dir);
	176	if (err)
	177	goto out;
	178
	179	inode = ext2_new_inode (dir, S_IFLNK \| S_IRWXUGO, &dentry->d_name);
	180	err = PTR_ERR(inode);
	181	if (IS_ERR(inode))
	182	goto out;
	183
	184	if (l > sizeof (EXT2_I(inode)->i_data)) {
	185	/* slow symlink */
	186	inode->i_op = &ext2_symlink_inode_operations;
	187	inode_nohighmem(inode);
	188	if (test_opt(inode->i_sb, NOBH))
	189	inode->i_mapping->a_ops = &ext2_nobh_aops;
	190	else
	191	inode->i_mapping->a_ops = &ext2_aops;
	192	err = page_symlink(inode, symname, l);
	193	if (err)
	194	goto out_fail;
	195	} else {
	196	/* fast symlink */
	197	inode->i_op = &ext2_fast_symlink_inode_operations;
	198	inode->i_link = (char*)EXT2_I(inode)->i_data;
	199	memcpy(inode->i_link, symname, l);
	200	inode->i_size = l-1;
	201	}
	202	mark_inode_dirty(inode);
	203
	204	err = ext2_add_nondir(dentry, inode);
	205	out:
	206	return err;
	207
	208	out_fail:
	209	inode_dec_link_count(inode);
	210	unlock_new_inode(inode);
	211	iput (inode);
	212	goto out;
	213	}
	214
	215	static int ext2_link (struct dentry * old_dentry, struct inode * dir,
	216	struct dentry *dentry)
	217	{
	218	struct inode *inode = d_inode(old_dentry);
	219	int err;
	220
	221	err = dquot_initialize(dir);
	222	if (err)
	223	return err;
	224
	225	inode->i_ctime = current_time(inode);
	226	inode_inc_link_count(inode);
	227	ihold(inode);
	228
	229	err = ext2_add_link(dentry, inode);
	230	if (!err) {
	231	d_instantiate(dentry, inode);
	232	return 0;
	233	}
	234	inode_dec_link_count(inode);
	235	iput(inode);
	236	return err;
	237	}
	238
	239	static int ext2_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
	240	{
	241	struct inode * inode;
	242	int err;
	243
	244	err = dquot_initialize(dir);
	245	if (err)
	246	return err;
	247
	248	inode_inc_link_count(dir);
	249
	250	inode = ext2_new_inode(dir, S_IFDIR \| mode, &dentry->d_name);
	251	err = PTR_ERR(inode);
	252	if (IS_ERR(inode))
	253	goto out_dir;
	254
	255	inode->i_op = &ext2_dir_inode_operations;
	256	inode->i_fop = &ext2_dir_operations;
	257	if (test_opt(inode->i_sb, NOBH))
	258	inode->i_mapping->a_ops = &ext2_nobh_aops;
	259	else
	260	inode->i_mapping->a_ops = &ext2_aops;
	261
	262	inode_inc_link_count(inode);
	263
	264	err = ext2_make_empty(inode, dir);
	265	if (err)
	266	goto out_fail;
	267
	268	err = ext2_add_link(dentry, inode);
	269	if (err)
	270	goto out_fail;
	271
	272	unlock_new_inode(inode);
	273	d_instantiate(dentry, inode);
	274	out:
	275	return err;
	276
	277	out_fail:
	278	inode_dec_link_count(inode);
	279	inode_dec_link_count(inode);
	280	unlock_new_inode(inode);
	281	iput(inode);
	282	out_dir:
	283	inode_dec_link_count(dir);
	284	goto out;
	285	}
	286
	287	static int ext2_unlink(struct inode * dir, struct dentry *dentry)
	288	{
	289	struct inode * inode = d_inode(dentry);
	290	struct ext2_dir_entry_2 * de;
	291	struct page * page;
	292	int err;
	293
	294	err = dquot_initialize(dir);
	295	if (err)
	296	goto out;
	297
	298	de = ext2_find_entry (dir, &dentry->d_name, &page);
	299	if (!de) {
	300	err = -ENOENT;
	301	goto out;
	302	}
	303
	304	err = ext2_delete_entry (de, page);
	305	if (err)
	306	goto out;
	307
	308	inode->i_ctime = dir->i_ctime;
	309	inode_dec_link_count(inode);
	310	err = 0;
	311	out:
	312	return err;
	313	}
	314
	315	static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
	316	{
	317	struct inode * inode = d_inode(dentry);
	318	int err = -ENOTEMPTY;
	319
	320	if (ext2_empty_dir(inode)) {
	321	err = ext2_unlink(dir, dentry);
	322	if (!err) {
	323	inode->i_size = 0;
	324	inode_dec_link_count(inode);
	325	inode_dec_link_count(dir);
	326	}
	327	}
	328	return err;
	329	}
	330
	331	static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
	332	struct inode * new_dir, struct dentry * new_dentry,
	333	unsigned int flags)
	334	{
	335	struct inode * old_inode = d_inode(old_dentry);
	336	struct inode * new_inode = d_inode(new_dentry);
	337	struct page * dir_page = NULL;
	338	struct ext2_dir_entry_2 * dir_de = NULL;
	339	struct page * old_page;
	340	struct ext2_dir_entry_2 * old_de;
	341	int err;
	342
	343	if (flags & ~RENAME_NOREPLACE)
	344	return -EINVAL;
	345
	346	err = dquot_initialize(old_dir);
	347	if (err)
	348	goto out;
	349
	350	err = dquot_initialize(new_dir);
	351	if (err)
	352	goto out;
	353
	354	old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page);
	355	if (!old_de) {
	356	err = -ENOENT;
	357	goto out;
	358	}
	359
	360	if (S_ISDIR(old_inode->i_mode)) {
	361	err = -EIO;
	362	dir_de = ext2_dotdot(old_inode, &dir_page);
	363	if (!dir_de)
	364	goto out_old;
	365	}
	366
	367	if (new_inode) {
	368	struct page *new_page;
	369	struct ext2_dir_entry_2 *new_de;
	370
	371	err = -ENOTEMPTY;
	372	if (dir_de && !ext2_empty_dir (new_inode))
	373	goto out_dir;
	374
	375	err = -ENOENT;
	376	new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page);
	377	if (!new_de)
	378	goto out_dir;
	379	ext2_set_link(new_dir, new_de, new_page, old_inode, 1);
	380	new_inode->i_ctime = current_time(new_inode);
	381	if (dir_de)
	382	drop_nlink(new_inode);
	383	inode_dec_link_count(new_inode);
	384	} else {
	385	err = ext2_add_link(new_dentry, old_inode);
	386	if (err)
	387	goto out_dir;
	388	if (dir_de)
	389	inode_inc_link_count(new_dir);
	390	}
	391
	392	/*
	393	* Like most other Unix systems, set the ctime for inodes on a
	394	* rename.
	395	*/
	396	old_inode->i_ctime = current_time(old_inode);
	397	mark_inode_dirty(old_inode);
	398
	399	ext2_delete_entry (old_de, old_page);
	400
	401	if (dir_de) {
	402	if (old_dir != new_dir)
	403	ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0);
	404	else {
	405	kunmap(dir_page);
	406	put_page(dir_page);
	407	}
	408	inode_dec_link_count(old_dir);
	409	}
	410	return 0;
	411
	412
	413	out_dir:
	414	if (dir_de) {
	415	kunmap(dir_page);
	416	put_page(dir_page);
	417	}
	418	out_old:
	419	kunmap(old_page);
	420	put_page(old_page);
	421	out:
	422	return err;
	423	}
	424
	425	const struct inode_operations ext2_dir_inode_operations = {
	426	.create = ext2_create,
	427	.lookup = ext2_lookup,
	428	.link = ext2_link,
	429	.unlink = ext2_unlink,
	430	.symlink = ext2_symlink,
	431	.mkdir = ext2_mkdir,
	432	.rmdir = ext2_rmdir,
	433	.mknod = ext2_mknod,
	434	.rename = ext2_rename,
	435	#ifdef CONFIG_EXT2_FS_XATTR
	436	.listxattr = ext2_listxattr,
	437	#endif
	438	.setattr = ext2_setattr,
	439	.get_acl = ext2_get_acl,
	440	.set_acl = ext2_set_acl,
	441	.tmpfile = ext2_tmpfile,
	442	};
	443
	444	const struct inode_operations ext2_special_inode_operations = {
	445	#ifdef CONFIG_EXT2_FS_XATTR
	446	.listxattr = ext2_listxattr,
	447	#endif
	448	.setattr = ext2_setattr,
	449	.get_acl = ext2_get_acl,
	450	.set_acl = ext2_set_acl,
	451	};