[people/ms/linux.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);
	return d_splice_alias(inode, dentry);
}

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

static int minix_symlink(struct user_namespace *mnt_userns, 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 user_namespace *mnt_userns, 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 user_namespace *mnt_userns,
			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);
b0149516	31	if (ino)
a90a0880	32	inode = minix_iget(dir->i_sb, ino);
b0149516	33	return d_splice_alias(inode, dentry);
1da177e4 LT	34	}
1da177e4 LT	35
549c7297 CB	36	static int minix_mknod(struct user_namespace mnt_userns, struct inode dir,
549c7297 CB	37	struct dentry *dentry, umode_t mode, dev_t rdev)
1da177e4 LT	38	{
	39	int error;
	40	struct inode *inode;
	41
	42	if (!old_valid_dev(rdev))
	43	return -EINVAL;
	44
9eed1fb7	45	inode = minix_new_inode(dir, mode, &error);
1da177e4 LT	46
1da177e4 LT	47	if (inode) {
1da177e4 LT	48	minix_set_inode(inode, rdev);
	49	mark_inode_dirty(inode);
	50	error = add_nondir(dentry, inode);
	51	}
	52	return error;
	53	}
	54
549c7297 CB	55	static int minix_tmpfile(struct user_namespace mnt_userns, struct inode dir,
549c7297 CB	56	struct dentry *dentry, umode_t mode)
60545d0d AV	57	{
	58	int error;
	59	struct inode *inode = minix_new_inode(dir, mode, &error);
	60	if (inode) {
	61	minix_set_inode(inode, 0);
	62	mark_inode_dirty(inode);
	63	d_tmpfile(dentry, inode);
	64	}
	65	return error;
	66	}
	67
549c7297 CB	68	static int minix_create(struct user_namespace mnt_userns, struct inode dir,
549c7297 CB	69	struct dentry *dentry, umode_t mode, bool excl)
1da177e4	70	{
549c7297	71	return minix_mknod(mnt_userns, dir, dentry, mode, 0);
1da177e4 LT	72	}
1da177e4 LT	73
549c7297 CB	74	static int minix_symlink(struct user_namespace mnt_userns, struct inode dir,
549c7297 CB	75	struct dentry dentry, const char symname)
1da177e4 LT	76	{
	77	int err = -ENAMETOOLONG;
	78	int i = strlen(symname)+1;
	79	struct inode * inode;
	80
	81	if (i > dir->i_sb->s_blocksize)
	82	goto out;
	83
9eed1fb7	84	inode = minix_new_inode(dir, S_IFLNK \| 0777, &err);
1da177e4 LT	85	if (!inode)
	86	goto out;
	87
1da177e4 LT	88	minix_set_inode(inode, 0);
	89	err = page_symlink(inode, symname, i);
	90	if (err)
	91	goto out_fail;
	92
	93	err = add_nondir(dentry, inode);
	94	out:
	95	return err;
	96
	97	out_fail:
78ec7b69	98	inode_dec_link_count(inode);
1da177e4 LT	99	iput(inode);
	100	goto out;
	101	}
	102
	103	static int minix_link(struct dentry * old_dentry, struct inode * dir,
	104	struct dentry *dentry)
	105	{
2b0143b5	106	struct inode *inode = d_inode(old_dentry);
1da177e4	107
02027d42	108	inode->i_ctime = current_time(inode);
78ec7b69	109	inode_inc_link_count(inode);
7de9c6ee	110	ihold(inode);
1da177e4 LT	111	return add_nondir(dentry, inode);
	112	}
	113
549c7297 CB	114	static int minix_mkdir(struct user_namespace mnt_userns, struct inode dir,
549c7297 CB	115	struct dentry *dentry, umode_t mode)
1da177e4 LT	116	{
1da177e4 LT	117	struct inode * inode;
8de52778	118	int err;
1da177e4	119
78ec7b69	120	inode_inc_link_count(dir);
1da177e4	121
eee743fd	122	inode = minix_new_inode(dir, S_IFDIR \| mode, &err);
1da177e4 LT	123	if (!inode)
	124	goto out_dir;
	125
1da177e4 LT	126	minix_set_inode(inode, 0);
1da177e4 LT	127
78ec7b69	128	inode_inc_link_count(inode);
1da177e4 LT	129
	130	err = minix_make_empty(inode, dir);
	131	if (err)
	132	goto out_fail;
	133
	134	err = minix_add_link(dentry, inode);
	135	if (err)
	136	goto out_fail;
	137
	138	d_instantiate(dentry, inode);
	139	out:
	140	return err;
	141
	142	out_fail:
78ec7b69 AD	143	inode_dec_link_count(inode);
78ec7b69 AD	144	inode_dec_link_count(inode);
1da177e4 LT	145	iput(inode);
1da177e4 LT	146	out_dir:
78ec7b69	147	inode_dec_link_count(dir);
1da177e4 LT	148	goto out;
	149	}
	150
	151	static int minix_unlink(struct inode * dir, struct dentry *dentry)
	152	{
	153	int err = -ENOENT;
2b0143b5	154	struct inode * inode = d_inode(dentry);
1da177e4 LT	155	struct page * page;
	156	struct minix_dir_entry * de;
	157
	158	de = minix_find_entry(dentry, &page);
	159	if (!de)
	160	goto end_unlink;
	161
	162	err = minix_delete_entry(de, page);
	163	if (err)
	164	goto end_unlink;
	165
	166	inode->i_ctime = dir->i_ctime;
78ec7b69	167	inode_dec_link_count(inode);
1da177e4 LT	168	end_unlink:
	169	return err;
	170	}
	171
	172	static int minix_rmdir(struct inode * dir, struct dentry *dentry)
	173	{
2b0143b5	174	struct inode * inode = d_inode(dentry);
1da177e4 LT	175	int err = -ENOTEMPTY;
	176
	177	if (minix_empty_dir(inode)) {
	178	err = minix_unlink(dir, dentry);
	179	if (!err) {
78ec7b69 AD	180	inode_dec_link_count(dir);
78ec7b69 AD	181	inode_dec_link_count(inode);
1da177e4 LT	182	}
	183	}
	184	return err;
	185	}
	186
549c7297 CB	187	static int minix_rename(struct user_namespace *mnt_userns,
	188	struct inode old_dir, struct dentry old_dentry,
	189	struct inode new_dir, struct dentry new_dentry,
f03b8ad8	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	};