[net-next-2.6.git] / fs / generic_acl.c

/*
 * fs/generic_acl.c
 *
 * (C) 2005 Andreas Gruenbacher <agruen@suse.de>
 *
 * This file is released under the GPL.
 */

#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/generic_acl.h>

/**
 * generic_acl_list  -  Generic xattr_handler->list() operation
 * @ops:	Filesystem specific getacl and setacl callbacks
 */
size_t
generic_acl_list(struct inode *inode, struct generic_acl_operations *ops,
		 int type, char *list, size_t list_size)
{
	struct posix_acl *acl;
	const char *name;
	size_t size;

	acl = ops->getacl(inode, type);
	if (!acl)
		return 0;
	posix_acl_release(acl);

	switch(type) {
		case ACL_TYPE_ACCESS:
			name = POSIX_ACL_XATTR_ACCESS;
			break;

		case ACL_TYPE_DEFAULT:
			name = POSIX_ACL_XATTR_DEFAULT;
			break;

		default:
			return 0;
	}
	size = strlen(name) + 1;
	if (list && size <= list_size)
		memcpy(list, name, size);
	return size;
}

/**
 * generic_acl_get  -  Generic xattr_handler->get() operation
 * @ops:	Filesystem specific getacl and setacl callbacks
 */
int
generic_acl_get(struct inode *inode, struct generic_acl_operations *ops,
		int type, void *buffer, size_t size)
{
	struct posix_acl *acl;
	int error;

	acl = ops->getacl(inode, type);
	if (!acl)
		return -ENODATA;
	error = posix_acl_to_xattr(acl, buffer, size);
	posix_acl_release(acl);

	return error;
}

/**
 * generic_acl_set  -  Generic xattr_handler->set() operation
 * @ops:	Filesystem specific getacl and setacl callbacks
 */
int
generic_acl_set(struct inode *inode, struct generic_acl_operations *ops,
		int type, const void *value, size_t size)
{
	struct posix_acl *acl = NULL;
	int error;

	if (S_ISLNK(inode->i_mode))
		return -EOPNOTSUPP;
	if (!is_owner_or_cap(inode))
		return -EPERM;
	if (value) {
		acl = posix_acl_from_xattr(value, size);
		if (IS_ERR(acl))
			return PTR_ERR(acl);
	}
	if (acl) {
		mode_t mode;

		error = posix_acl_valid(acl);
		if (error)
			goto failed;
		switch(type) {
			case ACL_TYPE_ACCESS:
				mode = inode->i_mode;
				error = posix_acl_equiv_mode(acl, &mode);
				if (error < 0)
					goto failed;
				inode->i_mode = mode;
				if (error == 0) {
					posix_acl_release(acl);
					acl = NULL;
				}
				break;

			case ACL_TYPE_DEFAULT:
				if (!S_ISDIR(inode->i_mode)) {
					error = -EINVAL;
					goto failed;
				}
				break;
		}
	}
	ops->setacl(inode, type, acl);
	error = 0;
failed:
	posix_acl_release(acl);
	return error;
}

/**
 * generic_acl_init  -  Take care of acl inheritance at @inode create time
 * @ops:	Filesystem specific getacl and setacl callbacks
 *
 * Files created inside a directory with a default ACL inherit the
 * directory's default ACL.
 */
int
generic_acl_init(struct inode *inode, struct inode *dir,
		 struct generic_acl_operations *ops)
{
	struct posix_acl *acl = NULL;
	mode_t mode = inode->i_mode;
	int error;

	inode->i_mode = mode & ~current_umask();
	if (!S_ISLNK(inode->i_mode))
		acl = ops->getacl(dir, ACL_TYPE_DEFAULT);
	if (acl) {
		struct posix_acl *clone;

		if (S_ISDIR(inode->i_mode)) {
			clone = posix_acl_clone(acl, GFP_KERNEL);
			error = -ENOMEM;
			if (!clone)
				goto cleanup;
			ops->setacl(inode, ACL_TYPE_DEFAULT, clone);
			posix_acl_release(clone);
		}
		clone = posix_acl_clone(acl, GFP_KERNEL);
		error = -ENOMEM;
		if (!clone)
			goto cleanup;
		error = posix_acl_create_masq(clone, &mode);
		if (error >= 0) {
			inode->i_mode = mode;
			if (error > 0)
				ops->setacl(inode, ACL_TYPE_ACCESS, clone);
		}
		posix_acl_release(clone);
	}
	error = 0;

cleanup:
	posix_acl_release(acl);
	return error;
}

/**
 * generic_acl_chmod  -  change the access acl of @inode upon chmod()
 * @ops:	FIlesystem specific getacl and setacl callbacks
 *
 * A chmod also changes the permissions of the owner, group/mask, and
 * other ACL entries.
 */
int
generic_acl_chmod(struct inode *inode, struct generic_acl_operations *ops)
{
	struct posix_acl *acl, *clone;
	int error = 0;

	if (S_ISLNK(inode->i_mode))
		return -EOPNOTSUPP;
	acl = ops->getacl(inode, ACL_TYPE_ACCESS);
	if (acl) {
		clone = posix_acl_clone(acl, GFP_KERNEL);
		posix_acl_release(acl);
		if (!clone)
			return -ENOMEM;
		error = posix_acl_chmod_masq(clone, inode->i_mode);
		if (!error)
			ops->setacl(inode, ACL_TYPE_ACCESS, clone);
		posix_acl_release(clone);
	}
	return error;
}
Commit	Line	Data
f0c8bd16 AG	1	/*
	2	* fs/generic_acl.c
	3	*
	4	* (C) 2005 Andreas Gruenbacher <agruen@suse.de>
	5	*
	6	* This file is released under the GPL.
	7	*/
	8
	9	#include <linux/sched.h>
	10	#include <linux/fs.h>
	11	#include <linux/generic_acl.h>
	12
	13	/**
	14	* generic_acl_list - Generic xattr_handler->list() operation
	15	* @ops: Filesystem specific getacl and setacl callbacks
	16	*/
	17	size_t
	18	generic_acl_list(struct inode inode, struct generic_acl_operations ops,
	19	int type, char *list, size_t list_size)
	20	{
	21	struct posix_acl *acl;
	22	const char *name;
	23	size_t size;
	24
	25	acl = ops->getacl(inode, type);
	26	if (!acl)
	27	return 0;
	28	posix_acl_release(acl);
	29
	30	switch(type) {
	31	case ACL_TYPE_ACCESS:
	32	name = POSIX_ACL_XATTR_ACCESS;
	33	break;
	34
	35	case ACL_TYPE_DEFAULT:
	36	name = POSIX_ACL_XATTR_DEFAULT;
	37	break;
	38
	39	default:
	40	return 0;
	41	}
	42	size = strlen(name) + 1;
	43	if (list && size <= list_size)
	44	memcpy(list, name, size);
	45	return size;
	46	}
	47
	48	/**
	49	* generic_acl_get - Generic xattr_handler->get() operation
	50	* @ops: Filesystem specific getacl and setacl callbacks
	51	*/
	52	int
	53	generic_acl_get(struct inode inode, struct generic_acl_operations ops,
	54	int type, void *buffer, size_t size)
	55	{
	56	struct posix_acl *acl;
	57	int error;
	58
	59	acl = ops->getacl(inode, type);
	60	if (!acl)
	61	return -ENODATA;
	62	error = posix_acl_to_xattr(acl, buffer, size);
	63	posix_acl_release(acl);
	64
65	return error;
66	}
67
68	/**
69	* generic_acl_set - Generic xattr_handler->set() operation
70	* @ops: Filesystem specific getacl and setacl callbacks
71	*/
72	int
73	generic_acl_set(struct inode inode, struct generic_acl_operations ops,
74	int type, const void *value, size_t size)
75	{
76	struct posix_acl *acl = NULL;
77	int error;
78
79	if (S_ISLNK(inode->i_mode))
80	return -EOPNOTSUPP;
3bd858ab	81	if (!is_owner_or_cap(inode))
f0c8bd16 AG	82	return -EPERM;
	83	if (value) {
	84	acl = posix_acl_from_xattr(value, size);
	85	if (IS_ERR(acl))
	86	return PTR_ERR(acl);
	87	}
	88	if (acl) {
	89	mode_t mode;
	90
	91	error = posix_acl_valid(acl);
	92	if (error)
	93	goto failed;
	94	switch(type) {
	95	case ACL_TYPE_ACCESS:
	96	mode = inode->i_mode;
	97	error = posix_acl_equiv_mode(acl, &mode);
	98	if (error < 0)
	99	goto failed;
	100	inode->i_mode = mode;
	101	if (error == 0) {
	102	posix_acl_release(acl);
	103	acl = NULL;
	104	}
	105	break;
	106
	107	case ACL_TYPE_DEFAULT:
	108	if (!S_ISDIR(inode->i_mode)) {
	109	error = -EINVAL;
	110	goto failed;
	111	}
	112	break;
	113	}
	114	}
	115	ops->setacl(inode, type, acl);
	116	error = 0;
	117	failed:
	118	posix_acl_release(acl);
	119	return error;
	120	}
	121
	122	/**
	123	* generic_acl_init - Take care of acl inheritance at @inode create time
	124	* @ops: Filesystem specific getacl and setacl callbacks
	125	*
	126	* Files created inside a directory with a default ACL inherit the
	127	* directory's default ACL.
	128	*/
	129	int
	130	generic_acl_init(struct inode inode, struct inode dir,
	131	struct generic_acl_operations *ops)
	132	{
	133	struct posix_acl *acl = NULL;
	134	mode_t mode = inode->i_mode;
	135	int error;
	136
ce3b0f8d	137	inode->i_mode = mode & ~current_umask();
f0c8bd16 AG	138	if (!S_ISLNK(inode->i_mode))
	139	acl = ops->getacl(dir, ACL_TYPE_DEFAULT);
	140	if (acl) {
	141	struct posix_acl *clone;
	142
	143	if (S_ISDIR(inode->i_mode)) {
	144	clone = posix_acl_clone(acl, GFP_KERNEL);
	145	error = -ENOMEM;
	146	if (!clone)
	147	goto cleanup;
	148	ops->setacl(inode, ACL_TYPE_DEFAULT, clone);
	149	posix_acl_release(clone);
	150	}
	151	clone = posix_acl_clone(acl, GFP_KERNEL);
	152	error = -ENOMEM;
	153	if (!clone)
	154	goto cleanup;
	155	error = posix_acl_create_masq(clone, &mode);
	156	if (error >= 0) {
	157	inode->i_mode = mode;
	158	if (error > 0)
	159	ops->setacl(inode, ACL_TYPE_ACCESS, clone);
	160	}
	161	posix_acl_release(clone);
	162	}
	163	error = 0;
	164
	165	cleanup:
	166	posix_acl_release(acl);
	167	return error;
	168	}
	169
	170	/**
	171	* generic_acl_chmod - change the access acl of @inode upon chmod()
	172	* @ops: FIlesystem specific getacl and setacl callbacks
	173	*
	174	* A chmod also changes the permissions of the owner, group/mask, and
	175	* other ACL entries.
	176	*/
	177	int
	178	generic_acl_chmod(struct inode inode, struct generic_acl_operations ops)
	179	{
	180	struct posix_acl acl, clone;
	181	int error = 0;
	182
	183	if (S_ISLNK(inode->i_mode))
	184	return -EOPNOTSUPP;
	185	acl = ops->getacl(inode, ACL_TYPE_ACCESS);
	186	if (acl) {
	187	clone = posix_acl_clone(acl, GFP_KERNEL);
	188	posix_acl_release(acl);
	189	if (!clone)
	190	return -ENOMEM;
	191	error = posix_acl_chmod_masq(clone, inode->i_mode);
	192	if (!error)
	193	ops->setacl(inode, ACL_TYPE_ACCESS, clone);
	194	posix_acl_release(clone);
	195	}
	196	return error;
	197	}