[linux.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(const 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, unsigned int flags)
{
	struct inode * inode = NULL;
	ino_t ino;

	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, umode_t 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, umode_t mode, bool excl)
{
	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 = d_inode(old_dentry);

	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, umode_t mode)
{
	struct inode * inode;
	int err;

	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 = d_inode(dentry);
	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 = d_inode(dentry);
	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 = d_inode(old_dentry);
	struct inode * new_inode = d_inode(new_dentry);
	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;
		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 {
		err = sysv_add_link(new_dentry, old_inode);
		if (err)
			goto out_dir;
		if (dir_de)
			inode_inc_link_count(new_dir);
	}

	sysv_delete_entry(old_de, old_page);
	mark_inode_dirty(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
da53be12	30	static int sysv_hash(const struct dentry dentry, struct qstr qstr)
1da177e4 LT	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
00cd8dd3	45	static struct dentry sysv_lookup(struct inode dir, struct dentry * dentry, unsigned int flags)
1da177e4 LT	46	{
	47	struct inode * inode = NULL;
	48	ino_t ino;
	49
1da177e4 LT	50	if (dentry->d_name.len > SYSV_NAMELEN)
	51	return ERR_PTR(-ENAMETOOLONG);
	52	ino = sysv_inode_by_name(dentry);
	53
	54	if (ino) {
b8e1343f DH	55	inode = sysv_iget(dir->i_sb, ino);
	56	if (IS_ERR(inode))
	57	return ERR_CAST(inode);
1da177e4 LT	58	}
	59	d_add(dentry, inode);
	60	return NULL;
	61	}
	62
1a67aafb	63	static int sysv_mknod(struct inode * dir, struct dentry * dentry, umode_t mode, dev_t rdev)
1da177e4 LT	64	{
	65	struct inode * inode;
	66	int err;
	67
	68	if (!old_valid_dev(rdev))
	69	return -EINVAL;
	70
	71	inode = sysv_new_inode(dir, mode);
	72	err = PTR_ERR(inode);
	73
	74	if (!IS_ERR(inode)) {
	75	sysv_set_inode(inode, rdev);
	76	mark_inode_dirty(inode);
	77	err = add_nondir(dentry, inode);
	78	}
	79	return err;
	80	}
	81
ebfc3b49	82	static int sysv_create(struct inode * dir, struct dentry * dentry, umode_t mode, bool excl)
1da177e4 LT	83	{
	84	return sysv_mknod(dir, dentry, mode, 0);
	85	}
	86
	87	static int sysv_symlink(struct inode * dir, struct dentry * dentry,
	88	const char * symname)
	89	{
	90	int err = -ENAMETOOLONG;
	91	int l = strlen(symname)+1;
	92	struct inode * inode;
	93
	94	if (l > dir->i_sb->s_blocksize)
	95	goto out;
	96
	97	inode = sysv_new_inode(dir, S_IFLNK\|0777);
	98	err = PTR_ERR(inode);
	99	if (IS_ERR(inode))
	100	goto out;
	101
	102	sysv_set_inode(inode, 0);
	103	err = page_symlink(inode, symname, l);
	104	if (err)
	105	goto out_fail;
	106
	107	mark_inode_dirty(inode);
	108	err = add_nondir(dentry, inode);
	109	out:
	110	return err;
	111
	112	out_fail:
4e907c3d	113	inode_dec_link_count(inode);
1da177e4 LT	114	iput(inode);
	115	goto out;
	116	}
	117
	118	static int sysv_link(struct dentry * old_dentry, struct inode * dir,
	119	struct dentry * dentry)
	120	{
2b0143b5	121	struct inode *inode = d_inode(old_dentry);
1da177e4	122
1da177e4	123	inode->i_ctime = CURRENT_TIME_SEC;
4e907c3d	124	inode_inc_link_count(inode);
7de9c6ee	125	ihold(inode);
1da177e4 LT	126
	127	return add_nondir(dentry, inode);
	128	}
	129
18bb1db3	130	static int sysv_mkdir(struct inode * dir, struct dentry *dentry, umode_t mode)
1da177e4 LT	131	{
1da177e4 LT	132	struct inode * inode;
8de52778	133	int err;
1da177e4	134
4e907c3d	135	inode_inc_link_count(dir);
1da177e4 LT	136
	137	inode = sysv_new_inode(dir, S_IFDIR\|mode);
	138	err = PTR_ERR(inode);
	139	if (IS_ERR(inode))
	140	goto out_dir;
	141
	142	sysv_set_inode(inode, 0);
	143
4e907c3d	144	inode_inc_link_count(inode);
1da177e4 LT	145
	146	err = sysv_make_empty(inode, dir);
	147	if (err)
	148	goto out_fail;
	149
	150	err = sysv_add_link(dentry, inode);
	151	if (err)
	152	goto out_fail;
	153
	154	d_instantiate(dentry, inode);
	155	out:
	156	return err;
	157
	158	out_fail:
4e907c3d AD	159	inode_dec_link_count(inode);
4e907c3d AD	160	inode_dec_link_count(inode);
1da177e4 LT	161	iput(inode);
1da177e4 LT	162	out_dir:
4e907c3d	163	inode_dec_link_count(dir);
1da177e4 LT	164	goto out;
	165	}
	166
	167	static int sysv_unlink(struct inode * dir, struct dentry * dentry)
	168	{
2b0143b5	169	struct inode * inode = d_inode(dentry);
1da177e4 LT	170	struct page * page;
	171	struct sysv_dir_entry * de;
	172	int err = -ENOENT;
	173
	174	de = sysv_find_entry(dentry, &page);
	175	if (!de)
	176	goto out;
	177
	178	err = sysv_delete_entry (de, page);
	179	if (err)
	180	goto out;
	181
	182	inode->i_ctime = dir->i_ctime;
4e907c3d	183	inode_dec_link_count(inode);
1da177e4 LT	184	out:
	185	return err;
	186	}
	187
	188	static int sysv_rmdir(struct inode * dir, struct dentry * dentry)
	189	{
2b0143b5	190	struct inode *inode = d_inode(dentry);
1da177e4 LT	191	int err = -ENOTEMPTY;
	192
	193	if (sysv_empty_dir(inode)) {
	194	err = sysv_unlink(dir, dentry);
	195	if (!err) {
	196	inode->i_size = 0;
4e907c3d AD	197	inode_dec_link_count(inode);
4e907c3d AD	198	inode_dec_link_count(dir);
1da177e4 LT	199	}
	200	}
	201	return err;
	202	}
	203
	204	/*
	205	* Anybody can rename anything with this: the permission checks are left to the
	206	* higher-level routines.
	207	*/
	208	static int sysv_rename(struct inode * old_dir, struct dentry * old_dentry,
	209	struct inode * new_dir, struct dentry * new_dentry)
	210	{
2b0143b5 DH	211	struct inode * old_inode = d_inode(old_dentry);
2b0143b5 DH	212	struct inode * new_inode = d_inode(new_dentry);
1da177e4 LT	213	struct page * dir_page = NULL;
	214	struct sysv_dir_entry * dir_de = NULL;
	215	struct page * old_page;
	216	struct sysv_dir_entry * old_de;
	217	int err = -ENOENT;
	218
	219	old_de = sysv_find_entry(old_dentry, &old_page);
	220	if (!old_de)
	221	goto out;
	222
	223	if (S_ISDIR(old_inode->i_mode)) {
	224	err = -EIO;
	225	dir_de = sysv_dotdot(old_inode, &dir_page);
	226	if (!dir_de)
	227	goto out_old;
	228	}
	229
	230	if (new_inode) {
	231	struct page * new_page;
	232	struct sysv_dir_entry * new_de;
	233
	234	err = -ENOTEMPTY;
	235	if (dir_de && !sysv_empty_dir(new_inode))
	236	goto out_dir;
	237
	238	err = -ENOENT;
	239	new_de = sysv_find_entry(new_dentry, &new_page);
	240	if (!new_de)
	241	goto out_dir;
1da177e4 LT	242	sysv_set_link(new_de, new_page, old_inode);
	243	new_inode->i_ctime = CURRENT_TIME_SEC;
	244	if (dir_de)
9a53c3a7	245	drop_nlink(new_inode);
4e907c3d	246	inode_dec_link_count(new_inode);
1da177e4	247	} else {
1da177e4	248	err = sysv_add_link(new_dentry, old_inode);
4787d45f	249	if (err)
1da177e4	250	goto out_dir;
1da177e4	251	if (dir_de)
4e907c3d	252	inode_inc_link_count(new_dir);
1da177e4 LT	253	}
	254
	255	sysv_delete_entry(old_de, old_page);
4787d45f	256	mark_inode_dirty(old_inode);
1da177e4 LT	257
	258	if (dir_de) {
	259	sysv_set_link(dir_de, dir_page, new_dir);
4e907c3d	260	inode_dec_link_count(old_dir);
1da177e4 LT	261	}
	262	return 0;
	263
	264	out_dir:
	265	if (dir_de) {
	266	kunmap(dir_page);
	267	page_cache_release(dir_page);
	268	}
	269	out_old:
	270	kunmap(old_page);
	271	page_cache_release(old_page);
	272	out:
	273	return err;
	274	}
	275
	276	/*
	277	* directories can handle most operations...
	278	*/
c5ef1c42	279	const struct inode_operations sysv_dir_inode_operations = {
1da177e4 LT	280	.create = sysv_create,
	281	.lookup = sysv_lookup,
	282	.link = sysv_link,
	283	.unlink = sysv_unlink,
	284	.symlink = sysv_symlink,
	285	.mkdir = sysv_mkdir,
	286	.rmdir = sysv_rmdir,
	287	.mknod = sysv_mknod,
	288	.rename = sysv_rename,
	289	.getattr = sysv_getattr,
	290	};