[linux-block.git] / fs / sysv / namei.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  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(dentry, 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);
	return d_splice_alias(inode, dentry);
}

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(inode);
	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,
		       unsigned int flags)
{
	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;

	if (flags & ~RENAME_NOREPLACE)
		return -EINVAL;

	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(new_inode);
		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);
		put_page(dir_page);
	}
out_old:
	kunmap(old_page);
	put_page(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
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* linux/fs/sysv/namei.c
	4	*
	5	* minix/namei.c
	6	* Copyright (C) 1991, 1992 Linus Torvalds
	7	*
	8	* coh/namei.c
	9	* Copyright (C) 1993 Pascal Haible, Bruno Haible
	10	*
	11	* sysv/namei.c
	12	* Copyright (C) 1993 Bruno Haible
	13	* Copyright (C) 1997, 1998 Krzysztof G. Baranowski
	14	*/
	15
	16	#include <linux/pagemap.h>
1da177e4 LT	17	#include "sysv.h"
1da177e4 LT	18
1da177e4 LT	19	static int add_nondir(struct dentry dentry, struct inode inode)
	20	{
	21	int err = sysv_add_link(dentry, inode);
	22	if (!err) {
	23	d_instantiate(dentry, inode);
	24	return 0;
	25	}
4e907c3d	26	inode_dec_link_count(inode);
1da177e4 LT	27	iput(inode);
	28	return err;
	29	}
	30
da53be12	31	static int sysv_hash(const struct dentry dentry, struct qstr qstr)
1da177e4 LT	32	{
	33	/* Truncate the name in place, avoids having to define a compare
	34	function. */
	35	if (qstr->len > SYSV_NAMELEN) {
	36	qstr->len = SYSV_NAMELEN;
8387ff25	37	qstr->hash = full_name_hash(dentry, qstr->name, qstr->len);
1da177e4 LT	38	}
	39	return 0;
	40	}
	41
e16404ed	42	const struct dentry_operations sysv_dentry_operations = {
1da177e4 LT	43	.d_hash = sysv_hash,
	44	};
	45
00cd8dd3	46	static struct dentry sysv_lookup(struct inode dir, struct dentry * dentry, unsigned int flags)
1da177e4 LT	47	{
	48	struct inode * inode = NULL;
	49	ino_t ino;
	50
1da177e4 LT	51	if (dentry->d_name.len > SYSV_NAMELEN)
	52	return ERR_PTR(-ENAMETOOLONG);
	53	ino = sysv_inode_by_name(dentry);
5bf35449	54	if (ino)
b8e1343f	55	inode = sysv_iget(dir->i_sb, ino);
5bf35449	56	return d_splice_alias(inode, dentry);
1da177e4 LT	57	}
1da177e4 LT	58
1a67aafb	59	static int sysv_mknod(struct inode * dir, struct dentry * dentry, umode_t mode, dev_t rdev)
1da177e4 LT	60	{
	61	struct inode * inode;
	62	int err;
	63
	64	if (!old_valid_dev(rdev))
	65	return -EINVAL;
	66
	67	inode = sysv_new_inode(dir, mode);
	68	err = PTR_ERR(inode);
	69
	70	if (!IS_ERR(inode)) {
	71	sysv_set_inode(inode, rdev);
	72	mark_inode_dirty(inode);
	73	err = add_nondir(dentry, inode);
	74	}
	75	return err;
	76	}
	77
ebfc3b49	78	static int sysv_create(struct inode * dir, struct dentry * dentry, umode_t mode, bool excl)
1da177e4 LT	79	{
	80	return sysv_mknod(dir, dentry, mode, 0);
	81	}
	82
	83	static int sysv_symlink(struct inode * dir, struct dentry * dentry,
	84	const char * symname)
	85	{
	86	int err = -ENAMETOOLONG;
	87	int l = strlen(symname)+1;
	88	struct inode * inode;
	89
	90	if (l > dir->i_sb->s_blocksize)
	91	goto out;
	92
	93	inode = sysv_new_inode(dir, S_IFLNK\|0777);
	94	err = PTR_ERR(inode);
	95	if (IS_ERR(inode))
	96	goto out;
	97
	98	sysv_set_inode(inode, 0);
	99	err = page_symlink(inode, symname, l);
	100	if (err)
	101	goto out_fail;
	102
	103	mark_inode_dirty(inode);
	104	err = add_nondir(dentry, inode);
	105	out:
	106	return err;
	107
	108	out_fail:
4e907c3d	109	inode_dec_link_count(inode);
1da177e4 LT	110	iput(inode);
	111	goto out;
	112	}
	113
	114	static int sysv_link(struct dentry * old_dentry, struct inode * dir,
	115	struct dentry * dentry)
	116	{
2b0143b5	117	struct inode *inode = d_inode(old_dentry);
1da177e4	118
02027d42	119	inode->i_ctime = current_time(inode);
4e907c3d	120	inode_inc_link_count(inode);
7de9c6ee	121	ihold(inode);
1da177e4 LT	122
	123	return add_nondir(dentry, inode);
	124	}
	125
18bb1db3	126	static int sysv_mkdir(struct inode * dir, struct dentry *dentry, umode_t mode)
1da177e4 LT	127	{
1da177e4 LT	128	struct inode * inode;
8de52778	129	int err;
1da177e4	130
4e907c3d	131	inode_inc_link_count(dir);
1da177e4 LT	132
	133	inode = sysv_new_inode(dir, S_IFDIR\|mode);
	134	err = PTR_ERR(inode);
	135	if (IS_ERR(inode))
	136	goto out_dir;
	137
	138	sysv_set_inode(inode, 0);
	139
4e907c3d	140	inode_inc_link_count(inode);
1da177e4 LT	141
	142	err = sysv_make_empty(inode, dir);
	143	if (err)
	144	goto out_fail;
	145
	146	err = sysv_add_link(dentry, inode);
	147	if (err)
	148	goto out_fail;
	149
	150	d_instantiate(dentry, inode);
	151	out:
	152	return err;
	153
	154	out_fail:
4e907c3d AD	155	inode_dec_link_count(inode);
4e907c3d AD	156	inode_dec_link_count(inode);
1da177e4 LT	157	iput(inode);
1da177e4 LT	158	out_dir:
4e907c3d	159	inode_dec_link_count(dir);
1da177e4 LT	160	goto out;
	161	}
	162
	163	static int sysv_unlink(struct inode * dir, struct dentry * dentry)
	164	{
2b0143b5	165	struct inode * inode = d_inode(dentry);
1da177e4 LT	166	struct page * page;
	167	struct sysv_dir_entry * de;
	168	int err = -ENOENT;
	169
	170	de = sysv_find_entry(dentry, &page);
	171	if (!de)
	172	goto out;
	173
	174	err = sysv_delete_entry (de, page);
	175	if (err)
	176	goto out;
	177
	178	inode->i_ctime = dir->i_ctime;
4e907c3d	179	inode_dec_link_count(inode);
1da177e4 LT	180	out:
	181	return err;
	182	}
	183
	184	static int sysv_rmdir(struct inode * dir, struct dentry * dentry)
	185	{
2b0143b5	186	struct inode *inode = d_inode(dentry);
1da177e4 LT	187	int err = -ENOTEMPTY;
	188
	189	if (sysv_empty_dir(inode)) {
	190	err = sysv_unlink(dir, dentry);
	191	if (!err) {
	192	inode->i_size = 0;
4e907c3d AD	193	inode_dec_link_count(inode);
4e907c3d AD	194	inode_dec_link_count(dir);
1da177e4 LT	195	}
	196	}
	197	return err;
	198	}
	199
	200	/*
	201	* Anybody can rename anything with this: the permission checks are left to the
	202	* higher-level routines.
	203	*/
	204	static int sysv_rename(struct inode * old_dir, struct dentry * old_dentry,
f03b8ad8 MS	205	struct inode * new_dir, struct dentry * new_dentry,
f03b8ad8 MS	206	unsigned int flags)
1da177e4	207	{
2b0143b5 DH	208	struct inode * old_inode = d_inode(old_dentry);
2b0143b5 DH	209	struct inode * new_inode = d_inode(new_dentry);
1da177e4 LT	210	struct page * dir_page = NULL;
	211	struct sysv_dir_entry * dir_de = NULL;
	212	struct page * old_page;
	213	struct sysv_dir_entry * old_de;
	214	int err = -ENOENT;
	215
f03b8ad8 MS	216	if (flags & ~RENAME_NOREPLACE)
	217	return -EINVAL;
	218
1da177e4 LT	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	242	sysv_set_link(new_de, new_page, old_inode);
02027d42	243	new_inode->i_ctime = current_time(new_inode);
1da177e4	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);
09cbfeaf	267	put_page(dir_page);
1da177e4 LT	268	}
	269	out_old:
	270	kunmap(old_page);
09cbfeaf	271	put_page(old_page);
1da177e4 LT	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	};