[thirdparty/kernel/stable.git] / fs / ext2 / namei.c

/*
 * 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"
#include "xip.h"

static inline int ext2_add_nondir(struct dentry *dentry, struct inode *inode)
{
	int err = ext2_add_link(dentry, inode);
	if (!err) {
		d_instantiate(dentry, inode);
		unlock_new_inode(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, struct nameidata *nd)
{
	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 = {.name = "..", .len = 2};
	unsigned long ino = ext2_inode_by_name(child->d_inode, &dotdot);
	if (!ino)
		return ERR_PTR(-ENOENT);
	return d_obtain_alias(ext2_iget(child->d_inode->i_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, struct nameidata *nd)
{
	struct inode *inode;

	dquot_initialize(dir);

	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 (ext2_use_xip(inode->i_sb)) {
		inode->i_mapping->a_ops = &ext2_aops_xip;
		inode->i_fop = &ext2_xip_file_operations;
	} else 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_mknod (struct inode * dir, struct dentry *dentry, umode_t mode, dev_t rdev)
{
	struct inode * inode;
	int err;

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

	dquot_initialize(dir);

	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;

	dquot_initialize(dir);

	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;
		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;
		memcpy((char*)(EXT2_I(inode)->i_data),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 = old_dentry->d_inode;
	int err;

	if (inode->i_nlink >= EXT2_LINK_MAX)
		return -EMLINK;

	dquot_initialize(dir);

	inode->i_ctime = CURRENT_TIME_SEC;
	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 = -EMLINK;

	if (dir->i_nlink >= EXT2_LINK_MAX)
		goto out;

	dquot_initialize(dir);

	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;

	d_instantiate(dentry, inode);
	unlock_new_inode(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 = dentry->d_inode;
	struct ext2_dir_entry_2 * de;
	struct page * page;
	int err = -ENOENT;

	dquot_initialize(dir);

	de = ext2_find_entry (dir, &dentry->d_name, &page);
	if (!de)
		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 = dentry->d_inode;
	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 )
{
	struct inode * old_inode = old_dentry->d_inode;
	struct inode * new_inode = new_dentry->d_inode;
	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 = -ENOENT;

	dquot_initialize(old_dir);
	dquot_initialize(new_dir);

	old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page);
	if (!old_de)
		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_SEC;
		if (dir_de)
			drop_nlink(new_inode);
		inode_dec_link_count(new_inode);
	} else {
		if (dir_de) {
			err = -EMLINK;
			if (new_dir->i_nlink >= EXT2_LINK_MAX)
				goto out_dir;
		}
		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_SEC;
	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);
			page_cache_release(dir_page);
		}
		inode_dec_link_count(old_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 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
	.setxattr	= generic_setxattr,
	.getxattr	= generic_getxattr,
	.listxattr	= ext2_listxattr,
	.removexattr	= generic_removexattr,
#endif
	.setattr	= ext2_setattr,
	.get_acl	= ext2_get_acl,
};

const struct inode_operations ext2_special_inode_operations = {
#ifdef CONFIG_EXT2_FS_XATTR
	.setxattr	= generic_setxattr,
	.getxattr	= generic_getxattr,
	.listxattr	= ext2_listxattr,
	.removexattr	= generic_removexattr,
#endif
	.setattr	= ext2_setattr,
	.get_acl	= ext2_get_acl,
};
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/ext2/namei.c
	3	*
	4	* Rewrite to pagecache. Almost all code had been changed, so blame me
	5	* if the things go wrong. Please, send bug reports to
	6	* viro@parcelfarce.linux.theplanet.co.uk
	7	*
	8	* Stuff here is basically a glue between the VFS and generic UNIXish
	9	* filesystem that keeps everything in pagecache. All knowledge of the
	10	* directory layout is in fs/ext2/dir.c - it turned out to be easily separatable
	11	* and it's easier to debug that way. In principle we might want to
	12	* generalize that a bit and turn it into a library. Or not.
	13	*
	14	* The only non-static object here is ext2_dir_inode_operations.
	15	*
	16	* TODO: get rid of kmap() use, add readahead.
	17	*
	18	* Copyright (C) 1992, 1993, 1994, 1995
	19	* Remy Card (card@masi.ibp.fr)
	20	* Laboratoire MASI - Institut Blaise Pascal
	21	* Universite Pierre et Marie Curie (Paris VI)
	22	*
	23	* from
	24	*
	25	* linux/fs/minix/namei.c
	26	*
	27	* Copyright (C) 1991, 1992 Linus Torvalds
	28	*
	29	* Big-endian to little-endian byte-swapping/bitmaps by
	30	* David S. Miller (davem@caip.rutgers.edu), 1995
	31	*/
	32
	33	#include <linux/pagemap.h>
907f4554	34	#include <linux/quotaops.h>
1da177e4 LT	35	#include "ext2.h"
	36	#include "xattr.h"
	37	#include "acl.h"
6d79125b	38	#include "xip.h"
1da177e4	39
1da177e4 LT	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	d_instantiate(dentry, inode);
41080b5a	45	unlock_new_inode(inode);
1da177e4 LT	46	return 0;
1da177e4 LT	47	}
a513b035	48	inode_dec_link_count(inode);
41080b5a	49	unlock_new_inode(inode);
1da177e4 LT	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, struct nameidata nd)
	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
a9885444	66	ino = ext2_inode_by_name(dir, &dentry->d_name);
1da177e4 LT	67	inode = NULL;
1da177e4 LT	68	if (ino) {
52fcf703	69	inode = ext2_iget(dir->i_sb, ino);
a9049376 AV	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);
4d6c13f8	75	}
1da177e4	76	}
082a05c6	77	return d_splice_alias(inode, dentry);
1da177e4 LT	78	}
	79
	80	struct dentry ext2_get_parent(struct dentry child)
	81	{
a9885444 AV	82	struct qstr dotdot = {.name = "..", .len = 2};
a9885444 AV	83	unsigned long ino = ext2_inode_by_name(child->d_inode, &dotdot);
1da177e4 LT	84	if (!ino)
1da177e4 LT	85	return ERR_PTR(-ENOENT);
44003728	86	return d_obtain_alias(ext2_iget(child->d_inode->i_sb, ino));
1da177e4 LT	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	*/
4acdaf27	97	static int ext2_create (struct inode * dir, struct dentry * dentry, umode_t mode, struct nameidata *nd)
1da177e4	98	{
907f4554 CH	99	struct inode *inode;
907f4554 CH	100
871a2931	101	dquot_initialize(dir);
907f4554	102
2a7dba39	103	inode = ext2_new_inode(dir, mode, &dentry->d_name);
907f4554 CH	104	if (IS_ERR(inode))
	105	return PTR_ERR(inode);
	106
	107	inode->i_op = &ext2_file_inode_operations;
	108	if (ext2_use_xip(inode->i_sb)) {
	109	inode->i_mapping->a_ops = &ext2_aops_xip;
	110	inode->i_fop = &ext2_xip_file_operations;
	111	} else 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;
1da177e4	117	}
907f4554 CH	118	mark_inode_dirty(inode);
907f4554 CH	119	return ext2_add_nondir(dentry, inode);
1da177e4 LT	120	}
1da177e4 LT	121
1a67aafb	122	static int ext2_mknod (struct inode * dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1da177e4 LT	123	{
	124	struct inode * inode;
	125	int err;
	126
	127	if (!new_valid_dev(rdev))
	128	return -EINVAL;
	129
871a2931	130	dquot_initialize(dir);
907f4554	131
2a7dba39	132	inode = ext2_new_inode (dir, mode, &dentry->d_name);
1da177e4 LT	133	err = PTR_ERR(inode);
	134	if (!IS_ERR(inode)) {
	135	init_special_inode(inode, inode->i_mode, rdev);
	136	#ifdef CONFIG_EXT2_FS_XATTR
	137	inode->i_op = &ext2_special_inode_operations;
	138	#endif
	139	mark_inode_dirty(inode);
	140	err = ext2_add_nondir(dentry, inode);
	141	}
	142	return err;
	143	}
	144
	145	static int ext2_symlink (struct inode * dir, struct dentry * dentry,
	146	const char * symname)
	147	{
	148	struct super_block * sb = dir->i_sb;
	149	int err = -ENAMETOOLONG;
	150	unsigned l = strlen(symname)+1;
	151	struct inode * inode;
	152
	153	if (l > sb->s_blocksize)
	154	goto out;
	155
871a2931	156	dquot_initialize(dir);
907f4554	157
2a7dba39	158	inode = ext2_new_inode (dir, S_IFLNK \| S_IRWXUGO, &dentry->d_name);
1da177e4 LT	159	err = PTR_ERR(inode);
	160	if (IS_ERR(inode))
	161	goto out;
	162
	163	if (l > sizeof (EXT2_I(inode)->i_data)) {
	164	/* slow symlink */
	165	inode->i_op = &ext2_symlink_inode_operations;
	166	if (test_opt(inode->i_sb, NOBH))
	167	inode->i_mapping->a_ops = &ext2_nobh_aops;
	168	else
	169	inode->i_mapping->a_ops = &ext2_aops;
	170	err = page_symlink(inode, symname, l);
	171	if (err)
	172	goto out_fail;
	173	} else {
	174	/* fast symlink */
	175	inode->i_op = &ext2_fast_symlink_inode_operations;
	176	memcpy((char*)(EXT2_I(inode)->i_data),symname,l);
	177	inode->i_size = l-1;
	178	}
	179	mark_inode_dirty(inode);
	180
	181	err = ext2_add_nondir(dentry, inode);
	182	out:
	183	return err;
	184
	185	out_fail:
a513b035	186	inode_dec_link_count(inode);
41080b5a	187	unlock_new_inode(inode);
1da177e4 LT	188	iput (inode);
	189	goto out;
	190	}
	191
	192	static int ext2_link (struct dentry * old_dentry, struct inode * dir,
	193	struct dentry *dentry)
	194	{
	195	struct inode *inode = old_dentry->d_inode;
41080b5a	196	int err;
1da177e4 LT	197
	198	if (inode->i_nlink >= EXT2_LINK_MAX)
	199	return -EMLINK;
	200
871a2931	201	dquot_initialize(dir);
907f4554	202
1da177e4	203	inode->i_ctime = CURRENT_TIME_SEC;
a513b035	204	inode_inc_link_count(inode);
7de9c6ee	205	ihold(inode);
1da177e4	206
41080b5a AV	207	err = ext2_add_link(dentry, inode);
	208	if (!err) {
	209	d_instantiate(dentry, inode);
	210	return 0;
	211	}
	212	inode_dec_link_count(inode);
	213	iput(inode);
	214	return err;
1da177e4 LT	215	}
1da177e4 LT	216
18bb1db3	217	static int ext2_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
1da177e4 LT	218	{
	219	struct inode * inode;
	220	int err = -EMLINK;
	221
	222	if (dir->i_nlink >= EXT2_LINK_MAX)
	223	goto out;
	224
871a2931	225	dquot_initialize(dir);
907f4554	226
a513b035	227	inode_inc_link_count(dir);
1da177e4	228
2a7dba39	229	inode = ext2_new_inode(dir, S_IFDIR \| mode, &dentry->d_name);
1da177e4 LT	230	err = PTR_ERR(inode);
	231	if (IS_ERR(inode))
	232	goto out_dir;
	233
	234	inode->i_op = &ext2_dir_inode_operations;
	235	inode->i_fop = &ext2_dir_operations;
	236	if (test_opt(inode->i_sb, NOBH))
	237	inode->i_mapping->a_ops = &ext2_nobh_aops;
	238	else
	239	inode->i_mapping->a_ops = &ext2_aops;
	240
a513b035	241	inode_inc_link_count(inode);
1da177e4 LT	242
	243	err = ext2_make_empty(inode, dir);
	244	if (err)
	245	goto out_fail;
	246
	247	err = ext2_add_link(dentry, inode);
	248	if (err)
	249	goto out_fail;
	250
	251	d_instantiate(dentry, inode);
41080b5a	252	unlock_new_inode(inode);
1da177e4 LT	253	out:
	254	return err;
	255
	256	out_fail:
a513b035 AD	257	inode_dec_link_count(inode);
a513b035 AD	258	inode_dec_link_count(inode);
41080b5a	259	unlock_new_inode(inode);
1da177e4 LT	260	iput(inode);
1da177e4 LT	261	out_dir:
a513b035	262	inode_dec_link_count(dir);
1da177e4 LT	263	goto out;
	264	}
	265
	266	static int ext2_unlink(struct inode * dir, struct dentry *dentry)
	267	{
	268	struct inode * inode = dentry->d_inode;
	269	struct ext2_dir_entry_2 * de;
	270	struct page * page;
	271	int err = -ENOENT;
	272
871a2931	273	dquot_initialize(dir);
907f4554	274
a9885444	275	de = ext2_find_entry (dir, &dentry->d_name, &page);
1da177e4 LT	276	if (!de)
	277	goto out;
	278
	279	err = ext2_delete_entry (de, page);
	280	if (err)
	281	goto out;
	282
	283	inode->i_ctime = dir->i_ctime;
a513b035	284	inode_dec_link_count(inode);
1da177e4 LT	285	err = 0;
	286	out:
	287	return err;
	288	}
	289
	290	static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
	291	{
	292	struct inode * inode = dentry->d_inode;
	293	int err = -ENOTEMPTY;
	294
	295	if (ext2_empty_dir(inode)) {
	296	err = ext2_unlink(dir, dentry);
	297	if (!err) {
	298	inode->i_size = 0;
a513b035 AD	299	inode_dec_link_count(inode);
a513b035 AD	300	inode_dec_link_count(dir);
1da177e4 LT	301	}
	302	}
	303	return err;
	304	}
	305
	306	static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
	307	struct inode * new_dir, struct dentry * new_dentry )
	308	{
	309	struct inode * old_inode = old_dentry->d_inode;
	310	struct inode * new_inode = new_dentry->d_inode;
	311	struct page * dir_page = NULL;
	312	struct ext2_dir_entry_2 * dir_de = NULL;
	313	struct page * old_page;
	314	struct ext2_dir_entry_2 * old_de;
	315	int err = -ENOENT;
	316
871a2931 CH	317	dquot_initialize(old_dir);
871a2931 CH	318	dquot_initialize(new_dir);
907f4554	319
a9885444	320	old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page);
1da177e4 LT	321	if (!old_de)
	322	goto out;
	323
	324	if (S_ISDIR(old_inode->i_mode)) {
	325	err = -EIO;
	326	dir_de = ext2_dotdot(old_inode, &dir_page);
	327	if (!dir_de)
	328	goto out_old;
	329	}
	330
	331	if (new_inode) {
	332	struct page *new_page;
	333	struct ext2_dir_entry_2 *new_de;
	334
	335	err = -ENOTEMPTY;
	336	if (dir_de && !ext2_empty_dir (new_inode))
	337	goto out_dir;
	338
	339	err = -ENOENT;
a9885444	340	new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page);
1da177e4 LT	341	if (!new_de)
1da177e4 LT	342	goto out_dir;
39fe7557	343	ext2_set_link(new_dir, new_de, new_page, old_inode, 1);
1da177e4 LT	344	new_inode->i_ctime = CURRENT_TIME_SEC;
1da177e4 LT	345	if (dir_de)
9a53c3a7	346	drop_nlink(new_inode);
a513b035	347	inode_dec_link_count(new_inode);
1da177e4 LT	348	} else {
	349	if (dir_de) {
	350	err = -EMLINK;
	351	if (new_dir->i_nlink >= EXT2_LINK_MAX)
	352	goto out_dir;
	353	}
1da177e4	354	err = ext2_add_link(new_dentry, old_inode);
e8a80c6f	355	if (err)
1da177e4	356	goto out_dir;
1da177e4	357	if (dir_de)
a513b035	358	inode_inc_link_count(new_dir);
1da177e4 LT	359	}
	360
	361	/*
	362	* Like most other Unix systems, set the ctime for inodes on a
	363	* rename.
1da177e4 LT	364	*/
1da177e4 LT	365	old_inode->i_ctime = CURRENT_TIME_SEC;
e8a80c6f	366	mark_inode_dirty(old_inode);
1da177e4 LT	367
1da177e4 LT	368	ext2_delete_entry (old_de, old_page);
1da177e4 LT	369
1da177e4 LT	370	if (dir_de) {
39fe7557 JK	371	if (old_dir != new_dir)
39fe7557 JK	372	ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0);
9de6886e NP	373	else {
	374	kunmap(dir_page);
	375	page_cache_release(dir_page);
	376	}
a513b035	377	inode_dec_link_count(old_dir);
1da177e4 LT	378	}
	379	return 0;
	380
	381
	382	out_dir:
	383	if (dir_de) {
	384	kunmap(dir_page);
	385	page_cache_release(dir_page);
	386	}
	387	out_old:
	388	kunmap(old_page);
	389	page_cache_release(old_page);
	390	out:
	391	return err;
	392	}
	393
754661f1	394	const struct inode_operations ext2_dir_inode_operations = {
1da177e4 LT	395	.create = ext2_create,
	396	.lookup = ext2_lookup,
	397	.link = ext2_link,
	398	.unlink = ext2_unlink,
	399	.symlink = ext2_symlink,
	400	.mkdir = ext2_mkdir,
	401	.rmdir = ext2_rmdir,
	402	.mknod = ext2_mknod,
	403	.rename = ext2_rename,
	404	#ifdef CONFIG_EXT2_FS_XATTR
	405	.setxattr = generic_setxattr,
	406	.getxattr = generic_getxattr,
	407	.listxattr = ext2_listxattr,
	408	.removexattr = generic_removexattr,
	409	#endif
	410	.setattr = ext2_setattr,
4e34e719	411	.get_acl = ext2_get_acl,
1da177e4 LT	412	};
1da177e4 LT	413
754661f1	414	const struct inode_operations ext2_special_inode_operations = {
1da177e4 LT	415	#ifdef CONFIG_EXT2_FS_XATTR
	416	.setxattr = generic_setxattr,
	417	.getxattr = generic_getxattr,
	418	.listxattr = ext2_listxattr,
	419	.removexattr = generic_removexattr,
	420	#endif
	421	.setattr = ext2_setattr,
4e34e719	422	.get_acl = ext2_get_acl,
1da177e4	423	};