[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / minix / namei.c

/*
 *  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 int minix_hash(struct dentry *dentry, struct qstr *qstr)
{
	unsigned long hash;
	int i;
	const unsigned char *name;

	i = minix_sb(dentry->d_inode->i_sb)->s_namelen;
	if (i >= qstr->len)
		return 0;
	/* Truncate the name in place, avoids having to define a compare
	   function. */
	qstr->len = i;
	name = qstr->name;
	hash = init_name_hash();
	while (i--)
		hash = partial_name_hash(*name++, hash);
	qstr->hash = end_name_hash(hash);
	return 0;
}

struct dentry_operations minix_dentry_operations = {
	.d_hash		= minix_hash,
};

static struct dentry *minix_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 > minix_sb(dir->i_sb)->s_namelen)
		return ERR_PTR(-ENAMETOOLONG);

	ino = minix_inode_by_name(dentry);
	if (ino) {
		inode = iget(dir->i_sb, ino);
 
		if (!inode)
			return ERR_PTR(-EACCES);
	}
	d_add(dentry, inode);
	return NULL;
}

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

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

	inode = minix_new_inode(dir, &error);

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

static int minix_create(struct inode * dir, struct dentry *dentry, int mode,
		struct nameidata *nd)
{
	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, &err);
	if (!inode)
		goto out;

	inode->i_mode = S_IFLNK | 0777;
	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 = old_dentry->d_inode;

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

	inode->i_ctime = CURRENT_TIME_SEC;
	inode_inc_link_count(inode);
	atomic_inc(&inode->i_count);
	return add_nondir(dentry, inode);
}

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

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

	inode_inc_link_count(dir);

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

	inode->i_mode = S_IFDIR | mode;
	if (dir->i_mode & S_ISGID)
		inode->i_mode |= S_ISGID;
	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 = dentry->d_inode;
	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 = dentry->d_inode;
	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)
{
	struct minix_sb_info * info = minix_sb(old_dir->i_sb);
	struct inode * old_inode = old_dentry->d_inode;
	struct inode * new_inode = new_dentry->d_inode;
	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;

	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;
		inode_inc_link_count(old_inode);
		minix_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 >= info->s_link_max)
				goto out_dir;
		}
		inode_inc_link_count(old_inode);
		err = minix_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);
	}

	minix_delete_entry(old_de, old_page);
	inode_dec_link_count(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);
		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 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,
};
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/minix/namei.c
	3	*
	4	* Copyright (C) 1991, 1992 Linus Torvalds
	5	*/
	6
	7	#include "minix.h"
	8
1da177e4 LT	9	static int add_nondir(struct dentry dentry, struct inode inode)
	10	{
	11	int err = minix_add_link(dentry, inode);
	12	if (!err) {
	13	d_instantiate(dentry, inode);
	14	return 0;
	15	}
78ec7b69	16	inode_dec_link_count(inode);
1da177e4 LT	17	iput(inode);
	18	return err;
	19	}
	20
	21	static int minix_hash(struct dentry dentry, struct qstr qstr)
	22	{
	23	unsigned long hash;
	24	int i;
	25	const unsigned char *name;
	26
	27	i = minix_sb(dentry->d_inode->i_sb)->s_namelen;
	28	if (i >= qstr->len)
	29	return 0;
	30	/* Truncate the name in place, avoids having to define a compare
	31	function. */
	32	qstr->len = i;
	33	name = qstr->name;
	34	hash = init_name_hash();
	35	while (i--)
	36	hash = partial_name_hash(*name++, hash);
	37	qstr->hash = end_name_hash(hash);
	38	return 0;
	39	}
	40
	41	struct dentry_operations minix_dentry_operations = {
	42	.d_hash = minix_hash,
	43	};
	44
	45	static struct dentry minix_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
	52	if (dentry->d_name.len > minix_sb(dir->i_sb)->s_namelen)
	53	return ERR_PTR(-ENAMETOOLONG);
	54
	55	ino = minix_inode_by_name(dentry);
	56	if (ino) {
	57	inode = iget(dir->i_sb, ino);
	58
	59	if (!inode)
	60	return ERR_PTR(-EACCES);
	61	}
	62	d_add(dentry, inode);
	63	return NULL;
	64	}
	65
	66	static int minix_mknod(struct inode * dir, struct dentry *dentry, int mode, dev_t rdev)
	67	{
	68	int error;
	69	struct inode *inode;
	70
	71	if (!old_valid_dev(rdev))
	72	return -EINVAL;
	73
	74	inode = minix_new_inode(dir, &error);
	75
	76	if (inode) {
	77	inode->i_mode = mode;
	78	minix_set_inode(inode, rdev);
	79	mark_inode_dirty(inode);
	80	error = add_nondir(dentry, inode);
81	}
82	return error;
83	}
84
85	static int minix_create(struct inode * dir, struct dentry *dentry, int mode,
86	struct nameidata *nd)
87	{
88	return minix_mknod(dir, dentry, mode, 0);
89	}
90
91	static int minix_symlink(struct inode * dir, struct dentry *dentry,
92	const char * symname)
93	{
94	int err = -ENAMETOOLONG;
95	int i = strlen(symname)+1;
96	struct inode * inode;
97
98	if (i > dir->i_sb->s_blocksize)
99	goto out;
100
101	inode = minix_new_inode(dir, &err);
102	if (!inode)
103	goto out;
104
105	inode->i_mode = S_IFLNK \| 0777;
106	minix_set_inode(inode, 0);
107	err = page_symlink(inode, symname, i);
108	if (err)
109	goto out_fail;
110
111	err = add_nondir(dentry, inode);
112	out:
113	return err;
114
115	out_fail:
78ec7b69	116	inode_dec_link_count(inode);
1da177e4 LT	117	iput(inode);
	118	goto out;
	119	}
	120
	121	static int minix_link(struct dentry * old_dentry, struct inode * dir,
	122	struct dentry *dentry)
	123	{
	124	struct inode *inode = old_dentry->d_inode;
	125
	126	if (inode->i_nlink >= minix_sb(inode->i_sb)->s_link_max)
	127	return -EMLINK;
	128
	129	inode->i_ctime = CURRENT_TIME_SEC;
78ec7b69	130	inode_inc_link_count(inode);
1da177e4 LT	131	atomic_inc(&inode->i_count);
	132	return add_nondir(dentry, inode);
	133	}
	134
	135	static int minix_mkdir(struct inode * dir, struct dentry *dentry, int mode)
	136	{
	137	struct inode * inode;
	138	int err = -EMLINK;
	139
	140	if (dir->i_nlink >= minix_sb(dir->i_sb)->s_link_max)
	141	goto out;
	142
78ec7b69	143	inode_inc_link_count(dir);
1da177e4 LT	144
	145	inode = minix_new_inode(dir, &err);
	146	if (!inode)
	147	goto out_dir;
	148
	149	inode->i_mode = S_IFDIR \| mode;
	150	if (dir->i_mode & S_ISGID)
	151	inode->i_mode \|= S_ISGID;
	152	minix_set_inode(inode, 0);
	153
78ec7b69	154	inode_inc_link_count(inode);
1da177e4 LT	155
	156	err = minix_make_empty(inode, dir);
	157	if (err)
	158	goto out_fail;
	159
	160	err = minix_add_link(dentry, inode);
	161	if (err)
	162	goto out_fail;
	163
	164	d_instantiate(dentry, inode);
	165	out:
	166	return err;
	167
	168	out_fail:
78ec7b69 AD	169	inode_dec_link_count(inode);
78ec7b69 AD	170	inode_dec_link_count(inode);
1da177e4 LT	171	iput(inode);
1da177e4 LT	172	out_dir:
78ec7b69	173	inode_dec_link_count(dir);
1da177e4 LT	174	goto out;
	175	}
	176
	177	static int minix_unlink(struct inode * dir, struct dentry *dentry)
	178	{
	179	int err = -ENOENT;
	180	struct inode * inode = dentry->d_inode;
	181	struct page * page;
	182	struct minix_dir_entry * de;
	183
	184	de = minix_find_entry(dentry, &page);
	185	if (!de)
	186	goto end_unlink;
	187
	188	err = minix_delete_entry(de, page);
	189	if (err)
	190	goto end_unlink;
	191
	192	inode->i_ctime = dir->i_ctime;
78ec7b69	193	inode_dec_link_count(inode);
1da177e4 LT	194	end_unlink:
	195	return err;
	196	}
	197
	198	static int minix_rmdir(struct inode * dir, struct dentry *dentry)
	199	{
	200	struct inode * inode = dentry->d_inode;
	201	int err = -ENOTEMPTY;
	202
	203	if (minix_empty_dir(inode)) {
	204	err = minix_unlink(dir, dentry);
	205	if (!err) {
78ec7b69 AD	206	inode_dec_link_count(dir);
78ec7b69 AD	207	inode_dec_link_count(inode);
1da177e4 LT	208	}
	209	}
	210	return err;
	211	}
	212
	213	static int minix_rename(struct inode * old_dir, struct dentry *old_dentry,
	214	struct inode * new_dir, struct dentry *new_dentry)
	215	{
	216	struct minix_sb_info * info = minix_sb(old_dir->i_sb);
	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 minix_dir_entry * dir_de = NULL;
	221	struct page * old_page;
	222	struct minix_dir_entry * old_de;
	223	int err = -ENOENT;
	224
	225	old_de = minix_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 = minix_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 minix_dir_entry * new_de;
	239
	240	err = -ENOTEMPTY;
	241	if (dir_de && !minix_empty_dir(new_inode))
	242	goto out_dir;
	243
	244	err = -ENOENT;
	245	new_de = minix_find_entry(new_dentry, &new_page);
	246	if (!new_de)
	247	goto out_dir;
78ec7b69	248	inode_inc_link_count(old_inode);
1da177e4 LT	249	minix_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);
78ec7b69	253	inode_dec_link_count(new_inode);
1da177e4 LT	254	} else {
	255	if (dir_de) {
	256	err = -EMLINK;
	257	if (new_dir->i_nlink >= info->s_link_max)
	258	goto out_dir;
	259	}
78ec7b69	260	inode_inc_link_count(old_inode);
1da177e4 LT	261	err = minix_add_link(new_dentry, old_inode);
1da177e4 LT	262	if (err) {
78ec7b69	263	inode_dec_link_count(old_inode);
1da177e4 LT	264	goto out_dir;
	265	}
	266	if (dir_de)
78ec7b69	267	inode_inc_link_count(new_dir);
1da177e4 LT	268	}
	269
	270	minix_delete_entry(old_de, old_page);
78ec7b69	271	inode_dec_link_count(old_inode);
1da177e4 LT	272
	273	if (dir_de) {
	274	minix_set_link(dir_de, dir_page, new_dir);
78ec7b69	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	*/
92e1d5be	294	const struct inode_operations minix_dir_inode_operations = {
1da177e4 LT	295	.create = minix_create,
	296	.lookup = minix_lookup,
	297	.link = minix_link,
	298	.unlink = minix_unlink,
	299	.symlink = minix_symlink,
	300	.mkdir = minix_mkdir,
	301	.rmdir = minix_rmdir,
	302	.mknod = minix_mknod,
	303	.rename = minix_rename,
	304	.getattr = minix_getattr,
	305	};