[net-next-2.6.git] / fs / sysv / namei.c

/*
 *  linux/fs/sysv/namei.c
 *
 *  minix/namei.c
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  coh/namei.c
 *  Copyright (C) 1993  Pascal Haible, Bruno Haible
 *
 *  sysv/namei.c
 *  Copyright (C) 1993  Bruno Haible
 *  Copyright (C) 1997, 1998  Krzysztof G. Baranowski
 */

#include <linux/pagemap.h>
#include "sysv.h"

static int add_nondir(struct dentry *dentry, struct inode *inode)
{
	int err = sysv_add_link(dentry, inode);
	if (!err) {
		d_instantiate(dentry, inode);
		return 0;
	}
	inode_dec_link_count(inode);
	iput(inode);
	return err;
}

static int sysv_hash(struct dentry *dentry, struct qstr *qstr)
{
	/* Truncate the name in place, avoids having to define a compare
	   function. */
	if (qstr->len > SYSV_NAMELEN) {
		qstr->len = SYSV_NAMELEN;
		qstr->hash = full_name_hash(qstr->name, qstr->len);
	}
	return 0;
}

const struct dentry_operations sysv_dentry_operations = {
	.d_hash		= sysv_hash,
};

static struct dentry *sysv_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
{
	struct inode * inode = NULL;
	ino_t ino;

	dentry->d_op = dir->i_sb->s_root->d_op;
	if (dentry->d_name.len > SYSV_NAMELEN)
		return ERR_PTR(-ENAMETOOLONG);
	ino = sysv_inode_by_name(dentry);

	if (ino) {
		inode = sysv_iget(dir->i_sb, ino);
		if (IS_ERR(inode))
			return ERR_CAST(inode);
	}
	d_add(dentry, inode);
	return NULL;
}

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

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

	inode = sysv_new_inode(dir, mode);
	err = PTR_ERR(inode);

	if (!IS_ERR(inode)) {
		sysv_set_inode(inode, rdev);
		mark_inode_dirty(inode);
		err = add_nondir(dentry, inode);
	}
	return err;
}

static int sysv_create(struct inode * dir, struct dentry * dentry, int mode, struct nameidata *nd)
{
	return sysv_mknod(dir, dentry, mode, 0);
}

static int sysv_symlink(struct inode * dir, struct dentry * dentry, 
	const char * symname)
{
	int err = -ENAMETOOLONG;
	int l = strlen(symname)+1;
	struct inode * inode;

	if (l > dir->i_sb->s_blocksize)
		goto out;

	inode = sysv_new_inode(dir, S_IFLNK|0777);
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out;
	
	sysv_set_inode(inode, 0);
	err = page_symlink(inode, symname, l);
	if (err)
		goto out_fail;

	mark_inode_dirty(inode);
	err = add_nondir(dentry, inode);
out:
	return err;

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

static int sysv_link(struct dentry * old_dentry, struct inode * dir, 
	struct dentry * dentry)
{
	struct inode *inode = old_dentry->d_inode;

	if (inode->i_nlink >= SYSV_SB(inode->i_sb)->s_link_max)
		return -EMLINK;

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

	return add_nondir(dentry, inode);
}

static int sysv_mkdir(struct inode * dir, struct dentry *dentry, int mode)
{
	struct inode * inode;
	int err = -EMLINK;

	if (dir->i_nlink >= SYSV_SB(dir->i_sb)->s_link_max) 
		goto out;
	inode_inc_link_count(dir);

	inode = sysv_new_inode(dir, S_IFDIR|mode);
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out_dir;

	sysv_set_inode(inode, 0);

	inode_inc_link_count(inode);

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

	err = sysv_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 sysv_unlink(struct inode * dir, struct dentry * dentry)
{
	struct inode * inode = dentry->d_inode;
	struct page * page;
	struct sysv_dir_entry * de;
	int err = -ENOENT;

	de = sysv_find_entry(dentry, &page);
	if (!de)
		goto out;

	err = sysv_delete_entry (de, page);
	if (err)
		goto out;

	inode->i_ctime = dir->i_ctime;
	inode_dec_link_count(inode);
out:
	return err;
}

static int sysv_rmdir(struct inode * dir, struct dentry * dentry)
{
	struct inode *inode = dentry->d_inode;
	int err = -ENOTEMPTY;

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

/*
 * Anybody can rename anything with this: the permission checks are left to the
 * higher-level routines.
 */
static int sysv_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 sysv_dir_entry * dir_de = NULL;
	struct page * old_page;
	struct sysv_dir_entry * old_de;
	int err = -ENOENT;

	old_de = sysv_find_entry(old_dentry, &old_page);
	if (!old_de)
		goto out;

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

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

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

		err = -ENOENT;
		new_de = sysv_find_entry(new_dentry, &new_page);
		if (!new_de)
			goto out_dir;
		inode_inc_link_count(old_inode);
		sysv_set_link(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 >= SYSV_SB(new_dir->i_sb)->s_link_max)
				goto out_dir;
		}
		inode_inc_link_count(old_inode);
		err = sysv_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);
	}

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

	if (dir_de) {
		sysv_set_link(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;
}

/*
 * directories can handle most operations...
 */
const struct inode_operations sysv_dir_inode_operations = {
	.create		= sysv_create,
	.lookup		= sysv_lookup,
	.link		= sysv_link,
	.unlink		= sysv_unlink,
	.symlink	= sysv_symlink,
	.mkdir		= sysv_mkdir,
	.rmdir		= sysv_rmdir,
	.mknod		= sysv_mknod,
	.rename		= sysv_rename,
	.getattr	= sysv_getattr,
};
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/sysv/namei.c
	3	*
	4	* minix/namei.c
	5	* Copyright (C) 1991, 1992 Linus Torvalds
	6	*
	7	* coh/namei.c
	8	* Copyright (C) 1993 Pascal Haible, Bruno Haible
	9	*
	10	* sysv/namei.c
	11	* Copyright (C) 1993 Bruno Haible
	12	* Copyright (C) 1997, 1998 Krzysztof G. Baranowski
	13	*/
	14
	15	#include <linux/pagemap.h>
1da177e4 LT	16	#include "sysv.h"
1da177e4 LT	17
1da177e4 LT	18	static int add_nondir(struct dentry dentry, struct inode inode)
	19	{
	20	int err = sysv_add_link(dentry, inode);
	21	if (!err) {
	22	d_instantiate(dentry, inode);
	23	return 0;
	24	}
4e907c3d	25	inode_dec_link_count(inode);
1da177e4 LT	26	iput(inode);
	27	return err;
	28	}
	29
	30	static int sysv_hash(struct dentry dentry, struct qstr qstr)
	31	{
	32	/* Truncate the name in place, avoids having to define a compare
	33	function. */
	34	if (qstr->len > SYSV_NAMELEN) {
	35	qstr->len = SYSV_NAMELEN;
	36	qstr->hash = full_name_hash(qstr->name, qstr->len);
	37	}
	38	return 0;
	39	}
	40
e16404ed	41	const struct dentry_operations sysv_dentry_operations = {
1da177e4 LT	42	.d_hash = sysv_hash,
	43	};
	44
	45	static struct dentry sysv_lookup(struct inode dir, struct dentry * dentry, struct nameidata *nd)
	46	{
	47	struct inode * inode = NULL;
	48	ino_t ino;
	49
	50	dentry->d_op = dir->i_sb->s_root->d_op;
	51	if (dentry->d_name.len > SYSV_NAMELEN)
	52	return ERR_PTR(-ENAMETOOLONG);
	53	ino = sysv_inode_by_name(dentry);
	54
	55	if (ino) {
b8e1343f DH	56	inode = sysv_iget(dir->i_sb, ino);
	57	if (IS_ERR(inode))
	58	return ERR_CAST(inode);
1da177e4 LT	59	}
	60	d_add(dentry, inode);
	61	return NULL;
	62	}
	63
	64	static int sysv_mknod(struct inode * dir, struct dentry * dentry, int mode, dev_t rdev)
	65	{
	66	struct inode * inode;
	67	int err;
	68
	69	if (!old_valid_dev(rdev))
	70	return -EINVAL;
	71
	72	inode = sysv_new_inode(dir, mode);
	73	err = PTR_ERR(inode);
	74
	75	if (!IS_ERR(inode)) {
	76	sysv_set_inode(inode, rdev);
	77	mark_inode_dirty(inode);
	78	err = add_nondir(dentry, inode);
	79	}
	80	return err;
	81	}
	82
	83	static int sysv_create(struct inode * dir, struct dentry * dentry, int mode, struct nameidata *nd)
	84	{
	85	return sysv_mknod(dir, dentry, mode, 0);
	86	}
	87
	88	static int sysv_symlink(struct inode * dir, struct dentry * dentry,
	89	const char * symname)
	90	{
	91	int err = -ENAMETOOLONG;
	92	int l = strlen(symname)+1;
	93	struct inode * inode;
	94
	95	if (l > dir->i_sb->s_blocksize)
	96	goto out;
	97
	98	inode = sysv_new_inode(dir, S_IFLNK\|0777);
	99	err = PTR_ERR(inode);
	100	if (IS_ERR(inode))
	101	goto out;
	102
	103	sysv_set_inode(inode, 0);
	104	err = page_symlink(inode, symname, l);
	105	if (err)
	106	goto out_fail;
	107
	108	mark_inode_dirty(inode);
	109	err = add_nondir(dentry, inode);
	110	out:
	111	return err;
	112
	113	out_fail:
4e907c3d	114	inode_dec_link_count(inode);
1da177e4 LT	115	iput(inode);
	116	goto out;
	117	}
	118
	119	static int sysv_link(struct dentry * old_dentry, struct inode * dir,
	120	struct dentry * dentry)
	121	{
	122	struct inode *inode = old_dentry->d_inode;
	123
	124	if (inode->i_nlink >= SYSV_SB(inode->i_sb)->s_link_max)
	125	return -EMLINK;
	126
	127	inode->i_ctime = CURRENT_TIME_SEC;
4e907c3d	128	inode_inc_link_count(inode);
7de9c6ee	129	ihold(inode);
1da177e4 LT	130
	131	return add_nondir(dentry, inode);
	132	}
	133
	134	static int sysv_mkdir(struct inode * dir, struct dentry *dentry, int mode)
	135	{
	136	struct inode * inode;
	137	int err = -EMLINK;
	138
	139	if (dir->i_nlink >= SYSV_SB(dir->i_sb)->s_link_max)
	140	goto out;
4e907c3d	141	inode_inc_link_count(dir);
1da177e4 LT	142
	143	inode = sysv_new_inode(dir, S_IFDIR\|mode);
	144	err = PTR_ERR(inode);
	145	if (IS_ERR(inode))
	146	goto out_dir;
	147
	148	sysv_set_inode(inode, 0);
	149
4e907c3d	150	inode_inc_link_count(inode);
1da177e4 LT	151
	152	err = sysv_make_empty(inode, dir);
	153	if (err)
	154	goto out_fail;
	155
	156	err = sysv_add_link(dentry, inode);
	157	if (err)
	158	goto out_fail;
	159
	160	d_instantiate(dentry, inode);
	161	out:
	162	return err;
	163
	164	out_fail:
4e907c3d AD	165	inode_dec_link_count(inode);
4e907c3d AD	166	inode_dec_link_count(inode);
1da177e4 LT	167	iput(inode);
1da177e4 LT	168	out_dir:
4e907c3d	169	inode_dec_link_count(dir);
1da177e4 LT	170	goto out;
	171	}
	172
	173	static int sysv_unlink(struct inode * dir, struct dentry * dentry)
	174	{
	175	struct inode * inode = dentry->d_inode;
	176	struct page * page;
	177	struct sysv_dir_entry * de;
	178	int err = -ENOENT;
	179
	180	de = sysv_find_entry(dentry, &page);
	181	if (!de)
	182	goto out;
	183
	184	err = sysv_delete_entry (de, page);
	185	if (err)
	186	goto out;
	187
	188	inode->i_ctime = dir->i_ctime;
4e907c3d	189	inode_dec_link_count(inode);
1da177e4 LT	190	out:
	191	return err;
	192	}
	193
	194	static int sysv_rmdir(struct inode * dir, struct dentry * dentry)
	195	{
	196	struct inode *inode = dentry->d_inode;
	197	int err = -ENOTEMPTY;
	198
	199	if (sysv_empty_dir(inode)) {
	200	err = sysv_unlink(dir, dentry);
	201	if (!err) {
	202	inode->i_size = 0;
4e907c3d AD	203	inode_dec_link_count(inode);
4e907c3d AD	204	inode_dec_link_count(dir);
1da177e4 LT	205	}
	206	}
	207	return err;
	208	}
	209
	210	/*
	211	* Anybody can rename anything with this: the permission checks are left to the
	212	* higher-level routines.
	213	*/
	214	static int sysv_rename(struct inode * old_dir, struct dentry * old_dentry,
	215	struct inode * new_dir, struct dentry * new_dentry)
	216	{
	217	struct inode * old_inode = old_dentry->d_inode;
	218	struct inode * new_inode = new_dentry->d_inode;
	219	struct page * dir_page = NULL;
	220	struct sysv_dir_entry * dir_de = NULL;
	221	struct page * old_page;
	222	struct sysv_dir_entry * old_de;
	223	int err = -ENOENT;
	224
	225	old_de = sysv_find_entry(old_dentry, &old_page);
	226	if (!old_de)
	227	goto out;
	228
	229	if (S_ISDIR(old_inode->i_mode)) {
	230	err = -EIO;
	231	dir_de = sysv_dotdot(old_inode, &dir_page);
	232	if (!dir_de)
	233	goto out_old;
	234	}
	235
	236	if (new_inode) {
	237	struct page * new_page;
	238	struct sysv_dir_entry * new_de;
	239
	240	err = -ENOTEMPTY;
	241	if (dir_de && !sysv_empty_dir(new_inode))
	242	goto out_dir;
	243
	244	err = -ENOENT;
	245	new_de = sysv_find_entry(new_dentry, &new_page);
	246	if (!new_de)
	247	goto out_dir;
4e907c3d	248	inode_inc_link_count(old_inode);
1da177e4 LT	249	sysv_set_link(new_de, new_page, old_inode);
	250	new_inode->i_ctime = CURRENT_TIME_SEC;
	251	if (dir_de)
9a53c3a7	252	drop_nlink(new_inode);
4e907c3d	253	inode_dec_link_count(new_inode);
1da177e4 LT	254	} else {
	255	if (dir_de) {
	256	err = -EMLINK;
	257	if (new_dir->i_nlink >= SYSV_SB(new_dir->i_sb)->s_link_max)
	258	goto out_dir;
	259	}
4e907c3d	260	inode_inc_link_count(old_inode);
1da177e4 LT	261	err = sysv_add_link(new_dentry, old_inode);
1da177e4 LT	262	if (err) {
4e907c3d	263	inode_dec_link_count(old_inode);
1da177e4 LT	264	goto out_dir;
	265	}
	266	if (dir_de)
4e907c3d	267	inode_inc_link_count(new_dir);
1da177e4 LT	268	}
	269
	270	sysv_delete_entry(old_de, old_page);
4e907c3d	271	inode_dec_link_count(old_inode);
1da177e4 LT	272
	273	if (dir_de) {
	274	sysv_set_link(dir_de, dir_page, new_dir);
4e907c3d	275	inode_dec_link_count(old_dir);
1da177e4 LT	276	}
	277	return 0;
	278
	279	out_dir:
	280	if (dir_de) {
	281	kunmap(dir_page);
	282	page_cache_release(dir_page);
	283	}
	284	out_old:
	285	kunmap(old_page);
	286	page_cache_release(old_page);
	287	out:
	288	return err;
	289	}
	290
	291	/*
	292	* directories can handle most operations...
	293	*/
c5ef1c42	294	const struct inode_operations sysv_dir_inode_operations = {
1da177e4 LT	295	.create = sysv_create,
	296	.lookup = sysv_lookup,
	297	.link = sysv_link,
	298	.unlink = sysv_unlink,
	299	.symlink = sysv_symlink,
	300	.mkdir = sysv_mkdir,
	301	.rmdir = sysv_rmdir,
	302	.mknod = sysv_mknod,
	303	.rename = sysv_rename,
	304	.getattr = sysv_getattr,
	305	};