[linux-2.6-block.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 "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 (IS_ERR(inode))
			return ERR_CAST(inode);
	}
	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, int mode, struct nameidata *nd)
{
	struct inode * inode = ext2_new_inode (dir, mode);
	int err = PTR_ERR(inode);
	if (!IS_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);
		err = ext2_add_nondir(dentry, inode);
	}
	return err;
}

static int ext2_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 = ext2_new_inode (dir, mode);
	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;

	inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO);
	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;

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

	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, int mode)
{
	struct inode * inode;
	int err = -EMLINK;

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

	inode_inc_link_count(dir);

	inode = ext2_new_inode (dir, S_IFDIR | mode);
	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;

	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;

	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;
		inode_inc_link_count(old_inode);
		ext2_set_link(new_dir, new_de, new_page, old_inode);
		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;
		}
		inode_inc_link_count(old_inode);
		err = ext2_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);
	}

	/*
	 * Like most other Unix systems, set the ctime for inodes on a
 	 * rename.
	 * inode_dec_link_count() will mark the inode dirty.
	 */
	old_inode->i_ctime = CURRENT_TIME_SEC;

	ext2_delete_entry (old_de, old_page);
	inode_dec_link_count(old_inode);

	if (dir_de) {
		ext2_set_link(old_inode, dir_de, dir_page, new_dir);
		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,
	.permission	= ext2_permission,
};

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,
	.permission	= ext2_permission,
};
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>
	34	#include "ext2.h"
	35	#include "xattr.h"
	36	#include "acl.h"
6d79125b	37	#include "xip.h"
1da177e4	38
1da177e4 LT	39	static inline int ext2_add_nondir(struct dentry dentry, struct inode inode)
	40	{
	41	int err = ext2_add_link(dentry, inode);
	42	if (!err) {
	43	d_instantiate(dentry, inode);
41080b5a	44	unlock_new_inode(inode);
1da177e4 LT	45	return 0;
1da177e4 LT	46	}
a513b035	47	inode_dec_link_count(inode);
41080b5a	48	unlock_new_inode(inode);
1da177e4 LT	49	iput(inode);
	50	return err;
	51	}
	52
	53	/*
	54	* Methods themselves.
	55	*/
	56
	57	static struct dentry ext2_lookup(struct inode dir, struct dentry dentry, struct nameidata nd)
	58	{
	59	struct inode * inode;
	60	ino_t ino;
	61
	62	if (dentry->d_name.len > EXT2_NAME_LEN)
	63	return ERR_PTR(-ENAMETOOLONG);
	64
a9885444	65	ino = ext2_inode_by_name(dir, &dentry->d_name);
1da177e4 LT	66	inode = NULL;
1da177e4 LT	67	if (ino) {
52fcf703 DH	68	inode = ext2_iget(dir->i_sb, ino);
	69	if (IS_ERR(inode))
	70	return ERR_CAST(inode);
1da177e4	71	}
082a05c6	72	return d_splice_alias(inode, dentry);
1da177e4 LT	73	}
	74
	75	struct dentry ext2_get_parent(struct dentry child)
	76	{
a9885444 AV	77	struct qstr dotdot = {.name = "..", .len = 2};
a9885444 AV	78	unsigned long ino = ext2_inode_by_name(child->d_inode, &dotdot);
1da177e4 LT	79	if (!ino)
1da177e4 LT	80	return ERR_PTR(-ENOENT);
44003728	81	return d_obtain_alias(ext2_iget(child->d_inode->i_sb, ino));
1da177e4 LT	82	}
	83
	84	/*
	85	* By the time this is called, we already have created
	86	* the directory cache entry for the new file, but it
	87	* is so far negative - it has no inode.
	88	*
	89	* If the create succeeds, we fill in the inode information
	90	* with d_instantiate().
	91	*/
	92	static int ext2_create (struct inode * dir, struct dentry * dentry, int mode, struct nameidata *nd)
	93	{
	94	struct inode * inode = ext2_new_inode (dir, mode);
	95	int err = PTR_ERR(inode);
	96	if (!IS_ERR(inode)) {
	97	inode->i_op = &ext2_file_inode_operations;
6d79125b CO	98	if (ext2_use_xip(inode->i_sb)) {
	99	inode->i_mapping->a_ops = &ext2_aops_xip;
	100	inode->i_fop = &ext2_xip_file_operations;
	101	} else if (test_opt(inode->i_sb, NOBH)) {
1da177e4	102	inode->i_mapping->a_ops = &ext2_nobh_aops;
6d79125b CO	103	inode->i_fop = &ext2_file_operations;
6d79125b CO	104	} else {
1da177e4	105	inode->i_mapping->a_ops = &ext2_aops;
6d79125b CO	106	inode->i_fop = &ext2_file_operations;
6d79125b CO	107	}
1da177e4 LT	108	mark_inode_dirty(inode);
	109	err = ext2_add_nondir(dentry, inode);
	110	}
	111	return err;
	112	}
	113
	114	static int ext2_mknod (struct inode * dir, struct dentry *dentry, int mode, dev_t rdev)
	115	{
	116	struct inode * inode;
	117	int err;
	118
	119	if (!new_valid_dev(rdev))
	120	return -EINVAL;
	121
	122	inode = ext2_new_inode (dir, mode);
	123	err = PTR_ERR(inode);
	124	if (!IS_ERR(inode)) {
	125	init_special_inode(inode, inode->i_mode, rdev);
	126	#ifdef CONFIG_EXT2_FS_XATTR
	127	inode->i_op = &ext2_special_inode_operations;
	128	#endif
	129	mark_inode_dirty(inode);
	130	err = ext2_add_nondir(dentry, inode);
	131	}
	132	return err;
	133	}
	134
	135	static int ext2_symlink (struct inode * dir, struct dentry * dentry,
	136	const char * symname)
	137	{
	138	struct super_block * sb = dir->i_sb;
	139	int err = -ENAMETOOLONG;
	140	unsigned l = strlen(symname)+1;
	141	struct inode * inode;
	142
	143	if (l > sb->s_blocksize)
	144	goto out;
	145
	146	inode = ext2_new_inode (dir, S_IFLNK \| S_IRWXUGO);
	147	err = PTR_ERR(inode);
	148	if (IS_ERR(inode))
	149	goto out;
	150
	151	if (l > sizeof (EXT2_I(inode)->i_data)) {
	152	/* slow symlink */
	153	inode->i_op = &ext2_symlink_inode_operations;
	154	if (test_opt(inode->i_sb, NOBH))
	155	inode->i_mapping->a_ops = &ext2_nobh_aops;
	156	else
	157	inode->i_mapping->a_ops = &ext2_aops;
	158	err = page_symlink(inode, symname, l);
	159	if (err)
	160	goto out_fail;
	161	} else {
	162	/* fast symlink */
	163	inode->i_op = &ext2_fast_symlink_inode_operations;
	164	memcpy((char*)(EXT2_I(inode)->i_data),symname,l);
	165	inode->i_size = l-1;
	166	}
	167	mark_inode_dirty(inode);
	168
	169	err = ext2_add_nondir(dentry, inode);
	170	out:
	171	return err;
172
173	out_fail:
a513b035	174	inode_dec_link_count(inode);
41080b5a	175	unlock_new_inode(inode);
1da177e4 LT	176	iput (inode);
	177	goto out;
	178	}
	179
	180	static int ext2_link (struct dentry * old_dentry, struct inode * dir,
	181	struct dentry *dentry)
	182	{
	183	struct inode *inode = old_dentry->d_inode;
41080b5a	184	int err;
1da177e4 LT	185
	186	if (inode->i_nlink >= EXT2_LINK_MAX)
	187	return -EMLINK;
	188
	189	inode->i_ctime = CURRENT_TIME_SEC;
a513b035	190	inode_inc_link_count(inode);
1da177e4 LT	191	atomic_inc(&inode->i_count);
1da177e4 LT	192
41080b5a AV	193	err = ext2_add_link(dentry, inode);
	194	if (!err) {
	195	d_instantiate(dentry, inode);
	196	return 0;
	197	}
	198	inode_dec_link_count(inode);
	199	iput(inode);
	200	return err;
1da177e4 LT	201	}
	202
	203	static int ext2_mkdir(struct inode * dir, struct dentry * dentry, int mode)
	204	{
	205	struct inode * inode;
	206	int err = -EMLINK;
	207
	208	if (dir->i_nlink >= EXT2_LINK_MAX)
	209	goto out;
	210
a513b035	211	inode_inc_link_count(dir);
1da177e4 LT	212
	213	inode = ext2_new_inode (dir, S_IFDIR \| mode);
	214	err = PTR_ERR(inode);
	215	if (IS_ERR(inode))
	216	goto out_dir;
	217
	218	inode->i_op = &ext2_dir_inode_operations;
	219	inode->i_fop = &ext2_dir_operations;
	220	if (test_opt(inode->i_sb, NOBH))
	221	inode->i_mapping->a_ops = &ext2_nobh_aops;
	222	else
	223	inode->i_mapping->a_ops = &ext2_aops;
	224
a513b035	225	inode_inc_link_count(inode);
1da177e4 LT	226
	227	err = ext2_make_empty(inode, dir);
	228	if (err)
	229	goto out_fail;
	230
	231	err = ext2_add_link(dentry, inode);
	232	if (err)
	233	goto out_fail;
	234
	235	d_instantiate(dentry, inode);
41080b5a	236	unlock_new_inode(inode);
1da177e4 LT	237	out:
	238	return err;
	239
	240	out_fail:
a513b035 AD	241	inode_dec_link_count(inode);
a513b035 AD	242	inode_dec_link_count(inode);
41080b5a	243	unlock_new_inode(inode);
1da177e4 LT	244	iput(inode);
1da177e4 LT	245	out_dir:
a513b035	246	inode_dec_link_count(dir);
1da177e4 LT	247	goto out;
	248	}
	249
	250	static int ext2_unlink(struct inode * dir, struct dentry *dentry)
	251	{
	252	struct inode * inode = dentry->d_inode;
	253	struct ext2_dir_entry_2 * de;
	254	struct page * page;
	255	int err = -ENOENT;
	256
a9885444	257	de = ext2_find_entry (dir, &dentry->d_name, &page);
1da177e4 LT	258	if (!de)
	259	goto out;
	260
	261	err = ext2_delete_entry (de, page);
	262	if (err)
	263	goto out;
	264
	265	inode->i_ctime = dir->i_ctime;
a513b035	266	inode_dec_link_count(inode);
1da177e4 LT	267	err = 0;
	268	out:
	269	return err;
	270	}
	271
	272	static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
	273	{
	274	struct inode * inode = dentry->d_inode;
	275	int err = -ENOTEMPTY;
	276
	277	if (ext2_empty_dir(inode)) {
	278	err = ext2_unlink(dir, dentry);
	279	if (!err) {
	280	inode->i_size = 0;
a513b035 AD	281	inode_dec_link_count(inode);
a513b035 AD	282	inode_dec_link_count(dir);
1da177e4 LT	283	}
	284	}
	285	return err;
	286	}
	287
	288	static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
	289	struct inode * new_dir, struct dentry * new_dentry )
	290	{
	291	struct inode * old_inode = old_dentry->d_inode;
	292	struct inode * new_inode = new_dentry->d_inode;
	293	struct page * dir_page = NULL;
	294	struct ext2_dir_entry_2 * dir_de = NULL;
	295	struct page * old_page;
	296	struct ext2_dir_entry_2 * old_de;
	297	int err = -ENOENT;
	298
a9885444	299	old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page);
1da177e4 LT	300	if (!old_de)
	301	goto out;
	302
	303	if (S_ISDIR(old_inode->i_mode)) {
	304	err = -EIO;
	305	dir_de = ext2_dotdot(old_inode, &dir_page);
	306	if (!dir_de)
	307	goto out_old;
	308	}
	309
	310	if (new_inode) {
	311	struct page *new_page;
	312	struct ext2_dir_entry_2 *new_de;
	313
	314	err = -ENOTEMPTY;
	315	if (dir_de && !ext2_empty_dir (new_inode))
	316	goto out_dir;
	317
	318	err = -ENOENT;
a9885444	319	new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page);
1da177e4 LT	320	if (!new_de)
1da177e4 LT	321	goto out_dir;
a513b035	322	inode_inc_link_count(old_inode);
1da177e4 LT	323	ext2_set_link(new_dir, new_de, new_page, old_inode);
	324	new_inode->i_ctime = CURRENT_TIME_SEC;
	325	if (dir_de)
9a53c3a7	326	drop_nlink(new_inode);
a513b035	327	inode_dec_link_count(new_inode);
1da177e4 LT	328	} else {
	329	if (dir_de) {
	330	err = -EMLINK;
	331	if (new_dir->i_nlink >= EXT2_LINK_MAX)
	332	goto out_dir;
	333	}
a513b035	334	inode_inc_link_count(old_inode);
1da177e4 LT	335	err = ext2_add_link(new_dentry, old_inode);
1da177e4 LT	336	if (err) {
a513b035	337	inode_dec_link_count(old_inode);
1da177e4 LT	338	goto out_dir;
	339	}
	340	if (dir_de)
a513b035	341	inode_inc_link_count(new_dir);
1da177e4 LT	342	}
	343
	344	/*
	345	* Like most other Unix systems, set the ctime for inodes on a
	346	* rename.
a513b035	347	* inode_dec_link_count() will mark the inode dirty.
1da177e4 LT	348	*/
	349	old_inode->i_ctime = CURRENT_TIME_SEC;
	350
	351	ext2_delete_entry (old_de, old_page);
a513b035	352	inode_dec_link_count(old_inode);
1da177e4 LT	353
	354	if (dir_de) {
	355	ext2_set_link(old_inode, dir_de, dir_page, new_dir);
a513b035	356	inode_dec_link_count(old_dir);
1da177e4 LT	357	}
	358	return 0;
	359
	360
	361	out_dir:
	362	if (dir_de) {
	363	kunmap(dir_page);
	364	page_cache_release(dir_page);
	365	}
	366	out_old:
	367	kunmap(old_page);
	368	page_cache_release(old_page);
	369	out:
	370	return err;
	371	}
	372
754661f1	373	const struct inode_operations ext2_dir_inode_operations = {
1da177e4 LT	374	.create = ext2_create,
	375	.lookup = ext2_lookup,
	376	.link = ext2_link,
	377	.unlink = ext2_unlink,
	378	.symlink = ext2_symlink,
	379	.mkdir = ext2_mkdir,
	380	.rmdir = ext2_rmdir,
	381	.mknod = ext2_mknod,
	382	.rename = ext2_rename,
	383	#ifdef CONFIG_EXT2_FS_XATTR
	384	.setxattr = generic_setxattr,
	385	.getxattr = generic_getxattr,
	386	.listxattr = ext2_listxattr,
	387	.removexattr = generic_removexattr,
	388	#endif
	389	.setattr = ext2_setattr,
	390	.permission = ext2_permission,
	391	};
	392
754661f1	393	const struct inode_operations ext2_special_inode_operations = {
1da177e4 LT	394	#ifdef CONFIG_EXT2_FS_XATTR
	395	.setxattr = generic_setxattr,
	396	.getxattr = generic_getxattr,
	397	.listxattr = ext2_listxattr,
	398	.removexattr = generic_removexattr,
	399	#endif
	400	.setattr = ext2_setattr,
	401	.permission = ext2_permission,
	402	};