[mirror_ubuntu-bionic-kernel.git] / fs / minix / namei.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/fs/minix/namei.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

#include "minix.h"

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

static struct dentry *minix_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags)
{
	struct inode * inode = NULL;
	ino_t ino;

	if (dentry->d_name.len > minix_sb(dir->i_sb)->s_namelen)
		return ERR_PTR(-ENAMETOOLONG);

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

static int minix_mknod(struct inode * dir, struct dentry *dentry, umode_t mode, dev_t rdev)
{
	int error;
	struct inode *inode;

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

	inode = minix_new_inode(dir, mode, &error);

	if (inode) {
		minix_set_inode(inode, rdev);
		mark_inode_dirty(inode);
		error = add_nondir(dentry, inode);
	}
	return error;
}

static int minix_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
{
	int error;
	struct inode *inode = minix_new_inode(dir, mode, &error);
	if (inode) {
		minix_set_inode(inode, 0);
		mark_inode_dirty(inode);
		d_tmpfile(dentry, inode);
	}
	return error;
}

static int minix_create(struct inode *dir, struct dentry *dentry, umode_t mode,
		bool excl)
{
	return minix_mknod(dir, dentry, mode, 0);
}

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

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

	inode = minix_new_inode(dir, S_IFLNK | 0777, &err);
	if (!inode)
		goto out;

	minix_set_inode(inode, 0);
	err = page_symlink(inode, symname, i);
	if (err)
		goto out_fail;

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

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

static int minix_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 minix_mkdir(struct inode * dir, struct dentry *dentry, umode_t mode)
{
	struct inode * inode;
	int err;

	inode_inc_link_count(dir);

	inode = minix_new_inode(dir, S_IFDIR | mode, &err);
	if (!inode)
		goto out_dir;

	minix_set_inode(inode, 0);

	inode_inc_link_count(inode);

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

	err = minix_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 minix_unlink(struct inode * dir, struct dentry *dentry)
{
	int err = -ENOENT;
	struct inode * inode = d_inode(dentry);
	struct page * page;
	struct minix_dir_entry * de;

	de = minix_find_entry(dentry, &page);
	if (!de)
		goto end_unlink;

	err = minix_delete_entry(de, page);
	if (err)
		goto end_unlink;

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

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

	if (minix_empty_dir(inode)) {
		err = minix_unlink(dir, dentry);
		if (!err) {
			inode_dec_link_count(dir);
			inode_dec_link_count(inode);
		}
	}
	return err;
}

static int minix_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 minix_dir_entry * dir_de = NULL;
	struct page * old_page;
	struct minix_dir_entry * old_de;
	int err = -ENOENT;

	if (flags & ~RENAME_NOREPLACE)
		return -EINVAL;

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

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

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

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

		err = -ENOENT;
		new_de = minix_find_entry(new_dentry, &new_page);
		if (!new_de)
			goto out_dir;
		minix_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 = minix_add_link(new_dentry, old_inode);
		if (err)
			goto out_dir;
		if (dir_de)
			inode_inc_link_count(new_dir);
	}

	minix_delete_entry(old_de, old_page);
	mark_inode_dirty(old_inode);

	if (dir_de) {
		minix_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 minix_dir_inode_operations = {
	.create		= minix_create,
	.lookup		= minix_lookup,
	.link		= minix_link,
	.unlink		= minix_unlink,
	.symlink	= minix_symlink,
	.mkdir		= minix_mkdir,
	.rmdir		= minix_rmdir,
	.mknod		= minix_mknod,
	.rename		= minix_rename,
	.getattr	= minix_getattr,
	.tmpfile	= minix_tmpfile,
};
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* linux/fs/minix/namei.c
	4	*
	5	* Copyright (C) 1991, 1992 Linus Torvalds
	6	*/
	7
	8	#include "minix.h"
	9
1da177e4 LT	10	static int add_nondir(struct dentry dentry, struct inode inode)
	11	{
	12	int err = minix_add_link(dentry, inode);
	13	if (!err) {
	14	d_instantiate(dentry, inode);
	15	return 0;
	16	}
78ec7b69	17	inode_dec_link_count(inode);
1da177e4 LT	18	iput(inode);
	19	return err;
	20	}
	21
00cd8dd3	22	static struct dentry minix_lookup(struct inode dir, struct dentry *dentry, unsigned int flags)
1da177e4 LT	23	{
	24	struct inode * inode = NULL;
	25	ino_t ino;
	26
1da177e4 LT	27	if (dentry->d_name.len > minix_sb(dir->i_sb)->s_namelen)
	28	return ERR_PTR(-ENAMETOOLONG);
	29
	30	ino = minix_inode_by_name(dentry);
	31	if (ino) {
a90a0880 DH	32	inode = minix_iget(dir->i_sb, ino);
	33	if (IS_ERR(inode))
	34	return ERR_CAST(inode);
1da177e4 LT	35	}
	36	d_add(dentry, inode);
	37	return NULL;
	38	}
	39
1a67aafb	40	static int minix_mknod(struct inode * dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1da177e4 LT	41	{
	42	int error;
	43	struct inode *inode;
	44
	45	if (!old_valid_dev(rdev))
	46	return -EINVAL;
	47
9eed1fb7	48	inode = minix_new_inode(dir, mode, &error);
1da177e4 LT	49
1da177e4 LT	50	if (inode) {
1da177e4 LT	51	minix_set_inode(inode, rdev);
	52	mark_inode_dirty(inode);
	53	error = add_nondir(dentry, inode);
	54	}
	55	return error;
	56	}
	57
60545d0d AV	58	static int minix_tmpfile(struct inode dir, struct dentry dentry, umode_t mode)
	59	{
	60	int error;
	61	struct inode *inode = minix_new_inode(dir, mode, &error);
	62	if (inode) {
	63	minix_set_inode(inode, 0);
	64	mark_inode_dirty(inode);
	65	d_tmpfile(dentry, inode);
	66	}
	67	return error;
	68	}
	69
4acdaf27	70	static int minix_create(struct inode dir, struct dentry dentry, umode_t mode,
ebfc3b49	71	bool excl)
1da177e4 LT	72	{
	73	return minix_mknod(dir, dentry, mode, 0);
	74	}
	75
	76	static int minix_symlink(struct inode * dir, struct dentry *dentry,
	77	const char * symname)
	78	{
	79	int err = -ENAMETOOLONG;
	80	int i = strlen(symname)+1;
	81	struct inode * inode;
	82
	83	if (i > dir->i_sb->s_blocksize)
	84	goto out;
	85
9eed1fb7	86	inode = minix_new_inode(dir, S_IFLNK \| 0777, &err);
1da177e4 LT	87	if (!inode)
	88	goto out;
	89
1da177e4 LT	90	minix_set_inode(inode, 0);
	91	err = page_symlink(inode, symname, i);
	92	if (err)
	93	goto out_fail;
	94
	95	err = add_nondir(dentry, inode);
	96	out:
	97	return err;
	98
	99	out_fail:
78ec7b69	100	inode_dec_link_count(inode);
1da177e4 LT	101	iput(inode);
	102	goto out;
	103	}
	104
	105	static int minix_link(struct dentry * old_dentry, struct inode * dir,
	106	struct dentry *dentry)
	107	{
2b0143b5	108	struct inode *inode = d_inode(old_dentry);
1da177e4	109
02027d42	110	inode->i_ctime = current_time(inode);
78ec7b69	111	inode_inc_link_count(inode);
7de9c6ee	112	ihold(inode);
1da177e4 LT	113	return add_nondir(dentry, inode);
	114	}
	115
18bb1db3	116	static int minix_mkdir(struct inode * dir, struct dentry *dentry, umode_t mode)
1da177e4 LT	117	{
1da177e4 LT	118	struct inode * inode;
8de52778	119	int err;
1da177e4	120
78ec7b69	121	inode_inc_link_count(dir);
1da177e4	122
eee743fd	123	inode = minix_new_inode(dir, S_IFDIR \| mode, &err);
1da177e4 LT	124	if (!inode)
	125	goto out_dir;
	126
1da177e4 LT	127	minix_set_inode(inode, 0);
1da177e4 LT	128
78ec7b69	129	inode_inc_link_count(inode);
1da177e4 LT	130
	131	err = minix_make_empty(inode, dir);
	132	if (err)
	133	goto out_fail;
	134
	135	err = minix_add_link(dentry, inode);
	136	if (err)
	137	goto out_fail;
	138
	139	d_instantiate(dentry, inode);
	140	out:
	141	return err;
	142
	143	out_fail:
78ec7b69 AD	144	inode_dec_link_count(inode);
78ec7b69 AD	145	inode_dec_link_count(inode);
1da177e4 LT	146	iput(inode);
1da177e4 LT	147	out_dir:
78ec7b69	148	inode_dec_link_count(dir);
1da177e4 LT	149	goto out;
	150	}
	151
	152	static int minix_unlink(struct inode * dir, struct dentry *dentry)
	153	{
	154	int err = -ENOENT;
2b0143b5	155	struct inode * inode = d_inode(dentry);
1da177e4 LT	156	struct page * page;
	157	struct minix_dir_entry * de;
	158
	159	de = minix_find_entry(dentry, &page);
	160	if (!de)
	161	goto end_unlink;
	162
	163	err = minix_delete_entry(de, page);
	164	if (err)
	165	goto end_unlink;
	166
	167	inode->i_ctime = dir->i_ctime;
78ec7b69	168	inode_dec_link_count(inode);
1da177e4 LT	169	end_unlink:
	170	return err;
	171	}
	172
	173	static int minix_rmdir(struct inode * dir, struct dentry *dentry)
	174	{
2b0143b5	175	struct inode * inode = d_inode(dentry);
1da177e4 LT	176	int err = -ENOTEMPTY;
	177
	178	if (minix_empty_dir(inode)) {
	179	err = minix_unlink(dir, dentry);
	180	if (!err) {
78ec7b69 AD	181	inode_dec_link_count(dir);
78ec7b69 AD	182	inode_dec_link_count(inode);
1da177e4 LT	183	}
	184	}
	185	return err;
	186	}
	187
	188	static int minix_rename(struct inode * old_dir, struct dentry *old_dentry,
f03b8ad8 MS	189	struct inode * new_dir, struct dentry *new_dentry,
f03b8ad8 MS	190	unsigned int flags)
1da177e4	191	{
2b0143b5 DH	192	struct inode * old_inode = d_inode(old_dentry);
2b0143b5 DH	193	struct inode * new_inode = d_inode(new_dentry);
1da177e4 LT	194	struct page * dir_page = NULL;
	195	struct minix_dir_entry * dir_de = NULL;
	196	struct page * old_page;
	197	struct minix_dir_entry * old_de;
	198	int err = -ENOENT;
	199
f03b8ad8 MS	200	if (flags & ~RENAME_NOREPLACE)
	201	return -EINVAL;
	202
1da177e4 LT	203	old_de = minix_find_entry(old_dentry, &old_page);
	204	if (!old_de)
	205	goto out;
	206
	207	if (S_ISDIR(old_inode->i_mode)) {
	208	err = -EIO;
	209	dir_de = minix_dotdot(old_inode, &dir_page);
	210	if (!dir_de)
	211	goto out_old;
	212	}
	213
	214	if (new_inode) {
	215	struct page * new_page;
	216	struct minix_dir_entry * new_de;
	217
	218	err = -ENOTEMPTY;
	219	if (dir_de && !minix_empty_dir(new_inode))
	220	goto out_dir;
	221
	222	err = -ENOENT;
	223	new_de = minix_find_entry(new_dentry, &new_page);
	224	if (!new_de)
	225	goto out_dir;
1da177e4	226	minix_set_link(new_de, new_page, old_inode);
02027d42	227	new_inode->i_ctime = current_time(new_inode);
1da177e4	228	if (dir_de)
9a53c3a7	229	drop_nlink(new_inode);
78ec7b69	230	inode_dec_link_count(new_inode);
1da177e4	231	} else {
1da177e4	232	err = minix_add_link(new_dentry, old_inode);
6f88049c	233	if (err)
1da177e4	234	goto out_dir;
1da177e4	235	if (dir_de)
78ec7b69	236	inode_inc_link_count(new_dir);
1da177e4 LT	237	}
	238
	239	minix_delete_entry(old_de, old_page);
6f88049c	240	mark_inode_dirty(old_inode);
1da177e4 LT	241
	242	if (dir_de) {
	243	minix_set_link(dir_de, dir_page, new_dir);
78ec7b69	244	inode_dec_link_count(old_dir);
1da177e4 LT	245	}
	246	return 0;
	247
	248	out_dir:
	249	if (dir_de) {
	250	kunmap(dir_page);
09cbfeaf	251	put_page(dir_page);
1da177e4 LT	252	}
	253	out_old:
	254	kunmap(old_page);
09cbfeaf	255	put_page(old_page);
1da177e4 LT	256	out:
	257	return err;
	258	}
	259
	260	/*
	261	* directories can handle most operations...
	262	*/
92e1d5be	263	const struct inode_operations minix_dir_inode_operations = {
1da177e4 LT	264	.create = minix_create,
	265	.lookup = minix_lookup,
	266	.link = minix_link,
	267	.unlink = minix_unlink,
	268	.symlink = minix_symlink,
	269	.mkdir = minix_mkdir,
	270	.rmdir = minix_rmdir,
	271	.mknod = minix_mknod,
	272	.rename = minix_rename,
	273	.getattr = minix_getattr,
60545d0d	274	.tmpfile = minix_tmpfile,
1da177e4	275	};