[deliverable/linux.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"

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(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, bool excl)
{
	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 (test_opt(inode->i_sb, DAX)) {
		inode->i_mapping->a_ops = &ext2_aops;
		inode->i_fop = &ext2_dax_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_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, DAX)) {
		inode->i_mapping->a_ops = &ext2_aops;
		inode->i_fop = &ext2_dax_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);
	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;

	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;

	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;

	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;

	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 = 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 {
		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,
	.set_acl	= ext2_set_acl,
	.tmpfile	= ext2_tmpfile,
};

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,
	.set_acl	= ext2_set_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"
	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) {
41080b5a	43	unlock_new_inode(inode);
8fc37ec5	44	d_instantiate(dentry, 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
00cd8dd3	57	static struct dentry ext2_lookup(struct inode dir, struct dentry *dentry, unsigned int flags)
1da177e4 LT	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	68	inode = ext2_iget(dir->i_sb, ino);
a9049376 AV	69	if (inode == ERR_PTR(-ESTALE)) {
	70	ext2_error(dir->i_sb, __func__,
	71	"deleted inode referenced: %lu",
	72	(unsigned long) ino);
	73	return ERR_PTR(-EIO);
4d6c13f8	74	}
1da177e4	75	}
082a05c6	76	return d_splice_alias(inode, dentry);
1da177e4 LT	77	}
	78
	79	struct dentry ext2_get_parent(struct dentry child)
	80	{
26fe5750	81	struct qstr dotdot = QSTR_INIT("..", 2);
a9885444	82	unsigned long ino = ext2_inode_by_name(child->d_inode, &dotdot);
1da177e4 LT	83	if (!ino)
1da177e4 LT	84	return ERR_PTR(-ENOENT);
44003728	85	return d_obtain_alias(ext2_iget(child->d_inode->i_sb, ino));
1da177e4 LT	86	}
	87
	88	/*
	89	* By the time this is called, we already have created
	90	* the directory cache entry for the new file, but it
	91	* is so far negative - it has no inode.
	92	*
	93	* If the create succeeds, we fill in the inode information
	94	* with d_instantiate().
	95	*/
ebfc3b49	96	static int ext2_create (struct inode * dir, struct dentry * dentry, umode_t mode, bool excl)
1da177e4	97	{
907f4554 CH	98	struct inode *inode;
907f4554 CH	99
871a2931	100	dquot_initialize(dir);
907f4554	101
2a7dba39	102	inode = ext2_new_inode(dir, mode, &dentry->d_name);
907f4554 CH	103	if (IS_ERR(inode))
	104	return PTR_ERR(inode);
	105
	106	inode->i_op = &ext2_file_inode_operations;
9c3ce9ec	107	if (test_opt(inode->i_sb, DAX)) {
97443aa8	108	inode->i_mapping->a_ops = &ext2_aops;
9c3ce9ec	109	inode->i_fop = &ext2_dax_file_operations;
907f4554 CH	110	} else if (test_opt(inode->i_sb, NOBH)) {
	111	inode->i_mapping->a_ops = &ext2_nobh_aops;
	112	inode->i_fop = &ext2_file_operations;
	113	} else {
	114	inode->i_mapping->a_ops = &ext2_aops;
	115	inode->i_fop = &ext2_file_operations;
1da177e4	116	}
907f4554 CH	117	mark_inode_dirty(inode);
907f4554 CH	118	return ext2_add_nondir(dentry, inode);
1da177e4 LT	119	}
1da177e4 LT	120
60545d0d AV	121	static int ext2_tmpfile(struct inode dir, struct dentry dentry, umode_t mode)
	122	{
	123	struct inode *inode = ext2_new_inode(dir, mode, NULL);
	124	if (IS_ERR(inode))
	125	return PTR_ERR(inode);
	126
	127	inode->i_op = &ext2_file_inode_operations;
9c3ce9ec	128	if (test_opt(inode->i_sb, DAX)) {
97443aa8	129	inode->i_mapping->a_ops = &ext2_aops;
9c3ce9ec	130	inode->i_fop = &ext2_dax_file_operations;
60545d0d AV	131	} else if (test_opt(inode->i_sb, NOBH)) {
	132	inode->i_mapping->a_ops = &ext2_nobh_aops;
	133	inode->i_fop = &ext2_file_operations;
	134	} else {
	135	inode->i_mapping->a_ops = &ext2_aops;
	136	inode->i_fop = &ext2_file_operations;
	137	}
	138	mark_inode_dirty(inode);
	139	d_tmpfile(dentry, inode);
	140	unlock_new_inode(inode);
	141	return 0;
	142	}
	143
1a67aafb	144	static int ext2_mknod (struct inode * dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1da177e4 LT	145	{
	146	struct inode * inode;
	147	int err;
	148
	149	if (!new_valid_dev(rdev))
	150	return -EINVAL;
	151
871a2931	152	dquot_initialize(dir);
907f4554	153
2a7dba39	154	inode = ext2_new_inode (dir, mode, &dentry->d_name);
1da177e4 LT	155	err = PTR_ERR(inode);
	156	if (!IS_ERR(inode)) {
	157	init_special_inode(inode, inode->i_mode, rdev);
	158	#ifdef CONFIG_EXT2_FS_XATTR
	159	inode->i_op = &ext2_special_inode_operations;
	160	#endif
	161	mark_inode_dirty(inode);
	162	err = ext2_add_nondir(dentry, inode);
	163	}
	164	return err;
	165	}
	166
	167	static int ext2_symlink (struct inode * dir, struct dentry * dentry,
	168	const char * symname)
	169	{
	170	struct super_block * sb = dir->i_sb;
	171	int err = -ENAMETOOLONG;
	172	unsigned l = strlen(symname)+1;
	173	struct inode * inode;
	174
	175	if (l > sb->s_blocksize)
	176	goto out;
	177
871a2931	178	dquot_initialize(dir);
907f4554	179
2a7dba39	180	inode = ext2_new_inode (dir, S_IFLNK \| S_IRWXUGO, &dentry->d_name);
1da177e4 LT	181	err = PTR_ERR(inode);
	182	if (IS_ERR(inode))
	183	goto out;
	184
	185	if (l > sizeof (EXT2_I(inode)->i_data)) {
	186	/* slow symlink */
	187	inode->i_op = &ext2_symlink_inode_operations;
	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	memcpy((char*)(EXT2_I(inode)->i_data),symname,l);
	199	inode->i_size = l-1;
	200	}
	201	mark_inode_dirty(inode);
	202
	203	err = ext2_add_nondir(dentry, inode);
	204	out:
	205	return err;
	206
	207	out_fail:
a513b035	208	inode_dec_link_count(inode);
41080b5a	209	unlock_new_inode(inode);
1da177e4 LT	210	iput (inode);
	211	goto out;
	212	}
	213
	214	static int ext2_link (struct dentry * old_dentry, struct inode * dir,
	215	struct dentry *dentry)
	216	{
	217	struct inode *inode = old_dentry->d_inode;
41080b5a	218	int err;
1da177e4	219
871a2931	220	dquot_initialize(dir);
907f4554	221
1da177e4	222	inode->i_ctime = CURRENT_TIME_SEC;
a513b035	223	inode_inc_link_count(inode);
7de9c6ee	224	ihold(inode);
1da177e4	225
41080b5a AV	226	err = ext2_add_link(dentry, inode);
	227	if (!err) {
	228	d_instantiate(dentry, inode);
	229	return 0;
	230	}
	231	inode_dec_link_count(inode);
	232	iput(inode);
	233	return err;
1da177e4 LT	234	}
1da177e4 LT	235
18bb1db3	236	static int ext2_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
1da177e4 LT	237	{
1da177e4 LT	238	struct inode * inode;
8de52778	239	int err;
1da177e4	240
871a2931	241	dquot_initialize(dir);
907f4554	242
a513b035	243	inode_inc_link_count(dir);
1da177e4	244
2a7dba39	245	inode = ext2_new_inode(dir, S_IFDIR \| mode, &dentry->d_name);
1da177e4 LT	246	err = PTR_ERR(inode);
	247	if (IS_ERR(inode))
	248	goto out_dir;
	249
	250	inode->i_op = &ext2_dir_inode_operations;
	251	inode->i_fop = &ext2_dir_operations;
	252	if (test_opt(inode->i_sb, NOBH))
	253	inode->i_mapping->a_ops = &ext2_nobh_aops;
	254	else
	255	inode->i_mapping->a_ops = &ext2_aops;
	256
a513b035	257	inode_inc_link_count(inode);
1da177e4 LT	258
	259	err = ext2_make_empty(inode, dir);
	260	if (err)
	261	goto out_fail;
	262
	263	err = ext2_add_link(dentry, inode);
	264	if (err)
	265	goto out_fail;
	266
41080b5a	267	unlock_new_inode(inode);
8fc37ec5	268	d_instantiate(dentry, inode);
1da177e4 LT	269	out:
	270	return err;
	271
	272	out_fail:
a513b035 AD	273	inode_dec_link_count(inode);
a513b035 AD	274	inode_dec_link_count(inode);
41080b5a	275	unlock_new_inode(inode);
1da177e4 LT	276	iput(inode);
1da177e4 LT	277	out_dir:
a513b035	278	inode_dec_link_count(dir);
1da177e4 LT	279	goto out;
	280	}
	281
	282	static int ext2_unlink(struct inode * dir, struct dentry *dentry)
	283	{
	284	struct inode * inode = dentry->d_inode;
	285	struct ext2_dir_entry_2 * de;
	286	struct page * page;
	287	int err = -ENOENT;
	288
871a2931	289	dquot_initialize(dir);
907f4554	290
a9885444	291	de = ext2_find_entry (dir, &dentry->d_name, &page);
1da177e4 LT	292	if (!de)
	293	goto out;
	294
	295	err = ext2_delete_entry (de, page);
	296	if (err)
	297	goto out;
	298
	299	inode->i_ctime = dir->i_ctime;
a513b035	300	inode_dec_link_count(inode);
1da177e4 LT	301	err = 0;
	302	out:
	303	return err;
	304	}
	305
	306	static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
	307	{
	308	struct inode * inode = dentry->d_inode;
	309	int err = -ENOTEMPTY;
	310
	311	if (ext2_empty_dir(inode)) {
	312	err = ext2_unlink(dir, dentry);
	313	if (!err) {
	314	inode->i_size = 0;
a513b035 AD	315	inode_dec_link_count(inode);
a513b035 AD	316	inode_dec_link_count(dir);
1da177e4 LT	317	}
	318	}
	319	return err;
	320	}
	321
	322	static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
	323	struct inode * new_dir, struct dentry * new_dentry )
	324	{
	325	struct inode * old_inode = old_dentry->d_inode;
	326	struct inode * new_inode = new_dentry->d_inode;
	327	struct page * dir_page = NULL;
	328	struct ext2_dir_entry_2 * dir_de = NULL;
	329	struct page * old_page;
	330	struct ext2_dir_entry_2 * old_de;
	331	int err = -ENOENT;
	332
871a2931 CH	333	dquot_initialize(old_dir);
871a2931 CH	334	dquot_initialize(new_dir);
907f4554	335
a9885444	336	old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page);
1da177e4 LT	337	if (!old_de)
	338	goto out;
	339
	340	if (S_ISDIR(old_inode->i_mode)) {
	341	err = -EIO;
	342	dir_de = ext2_dotdot(old_inode, &dir_page);
	343	if (!dir_de)
	344	goto out_old;
	345	}
	346
	347	if (new_inode) {
	348	struct page *new_page;
	349	struct ext2_dir_entry_2 *new_de;
	350
	351	err = -ENOTEMPTY;
	352	if (dir_de && !ext2_empty_dir (new_inode))
	353	goto out_dir;
	354
	355	err = -ENOENT;
a9885444	356	new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page);
1da177e4 LT	357	if (!new_de)
1da177e4 LT	358	goto out_dir;
39fe7557	359	ext2_set_link(new_dir, new_de, new_page, old_inode, 1);
1da177e4 LT	360	new_inode->i_ctime = CURRENT_TIME_SEC;
1da177e4 LT	361	if (dir_de)
9a53c3a7	362	drop_nlink(new_inode);
a513b035	363	inode_dec_link_count(new_inode);
1da177e4	364	} else {
1da177e4	365	err = ext2_add_link(new_dentry, old_inode);
e8a80c6f	366	if (err)
1da177e4	367	goto out_dir;
1da177e4	368	if (dir_de)
a513b035	369	inode_inc_link_count(new_dir);
1da177e4 LT	370	}
	371
	372	/*
	373	* Like most other Unix systems, set the ctime for inodes on a
	374	* rename.
1da177e4 LT	375	*/
1da177e4 LT	376	old_inode->i_ctime = CURRENT_TIME_SEC;
e8a80c6f	377	mark_inode_dirty(old_inode);
1da177e4 LT	378
1da177e4 LT	379	ext2_delete_entry (old_de, old_page);
1da177e4 LT	380
1da177e4 LT	381	if (dir_de) {
39fe7557 JK	382	if (old_dir != new_dir)
39fe7557 JK	383	ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0);
9de6886e NP	384	else {
	385	kunmap(dir_page);
	386	page_cache_release(dir_page);
	387	}
a513b035	388	inode_dec_link_count(old_dir);
1da177e4 LT	389	}
	390	return 0;
	391
	392
	393	out_dir:
	394	if (dir_de) {
	395	kunmap(dir_page);
	396	page_cache_release(dir_page);
	397	}
	398	out_old:
	399	kunmap(old_page);
	400	page_cache_release(old_page);
	401	out:
	402	return err;
	403	}
	404
754661f1	405	const struct inode_operations ext2_dir_inode_operations = {
1da177e4 LT	406	.create = ext2_create,
	407	.lookup = ext2_lookup,
	408	.link = ext2_link,
	409	.unlink = ext2_unlink,
	410	.symlink = ext2_symlink,
	411	.mkdir = ext2_mkdir,
	412	.rmdir = ext2_rmdir,
	413	.mknod = ext2_mknod,
	414	.rename = ext2_rename,
	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,
64e178a7	423	.set_acl = ext2_set_acl,
60545d0d	424	.tmpfile = ext2_tmpfile,
1da177e4 LT	425	};
1da177e4 LT	426
754661f1	427	const struct inode_operations ext2_special_inode_operations = {
1da177e4 LT	428	#ifdef CONFIG_EXT2_FS_XATTR
	429	.setxattr = generic_setxattr,
	430	.getxattr = generic_getxattr,
	431	.listxattr = ext2_listxattr,
	432	.removexattr = generic_removexattr,
	433	#endif
	434	.setattr = ext2_setattr,
4e34e719	435	.get_acl = ext2_get_acl,
64e178a7	436	.set_acl = ext2_set_acl,
1da177e4	437	};