[net-next-2.6.git] / fs / jffs2 / acl.c

/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright © 2006  NEC Corporation
 *
 * Created by KaiGai Kohei <kaigai@ak.jp.nec.com>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <linux/crc32.h>
#include <linux/jffs2.h>
#include <linux/xattr.h>
#include <linux/posix_acl_xattr.h>
#include <linux/mtd/mtd.h>
#include "nodelist.h"

static size_t jffs2_acl_size(int count)
{
	if (count <= 4) {
		return sizeof(struct jffs2_acl_header)
		       + count * sizeof(struct jffs2_acl_entry_short);
	} else {
		return sizeof(struct jffs2_acl_header)
		       + 4 * sizeof(struct jffs2_acl_entry_short)
		       + (count - 4) * sizeof(struct jffs2_acl_entry);
	}
}

static int jffs2_acl_count(size_t size)
{
	size_t s;

	size -= sizeof(struct jffs2_acl_header);
	if (size < 4 * sizeof(struct jffs2_acl_entry_short)) {
		if (size % sizeof(struct jffs2_acl_entry_short))
			return -1;
		return size / sizeof(struct jffs2_acl_entry_short);
	} else {
		s = size - 4 * sizeof(struct jffs2_acl_entry_short);
		if (s % sizeof(struct jffs2_acl_entry))
			return -1;
		return s / sizeof(struct jffs2_acl_entry) + 4;
	}
}

static struct posix_acl *jffs2_acl_from_medium(void *value, size_t size)
{
	void *end = value + size;
	struct jffs2_acl_header *header = value;
	struct jffs2_acl_entry *entry;
	struct posix_acl *acl;
	uint32_t ver;
	int i, count;

	if (!value)
		return NULL;
	if (size < sizeof(struct jffs2_acl_header))
		return ERR_PTR(-EINVAL);
	ver = je32_to_cpu(header->a_version);
	if (ver != JFFS2_ACL_VERSION) {
		JFFS2_WARNING("Invalid ACL version. (=%u)\n", ver);
		return ERR_PTR(-EINVAL);
	}

	value += sizeof(struct jffs2_acl_header);
	count = jffs2_acl_count(size);
	if (count < 0)
		return ERR_PTR(-EINVAL);
	if (count == 0)
		return NULL;

	acl = posix_acl_alloc(count, GFP_KERNEL);
	if (!acl)
		return ERR_PTR(-ENOMEM);

	for (i=0; i < count; i++) {
		entry = value;
		if (value + sizeof(struct jffs2_acl_entry_short) > end)
			goto fail;
		acl->a_entries[i].e_tag = je16_to_cpu(entry->e_tag);
		acl->a_entries[i].e_perm = je16_to_cpu(entry->e_perm);
		switch (acl->a_entries[i].e_tag) {
			case ACL_USER_OBJ:
			case ACL_GROUP_OBJ:
			case ACL_MASK:
			case ACL_OTHER:
				value += sizeof(struct jffs2_acl_entry_short);
				acl->a_entries[i].e_id = ACL_UNDEFINED_ID;
				break;

			case ACL_USER:
			case ACL_GROUP:
				value += sizeof(struct jffs2_acl_entry);
				if (value > end)
					goto fail;
				acl->a_entries[i].e_id = je32_to_cpu(entry->e_id);
				break;

			default:
				goto fail;
		}
	}
	if (value != end)
		goto fail;
	return acl;
 fail:
	posix_acl_release(acl);
	return ERR_PTR(-EINVAL);
}

static void *jffs2_acl_to_medium(const struct posix_acl *acl, size_t *size)
{
	struct jffs2_acl_header *header;
	struct jffs2_acl_entry *entry;
	void *e;
	size_t i;

	*size = jffs2_acl_size(acl->a_count);
	header = kmalloc(sizeof(*header) + acl->a_count * sizeof(*entry), GFP_KERNEL);
	if (!header)
		return ERR_PTR(-ENOMEM);
	header->a_version = cpu_to_je32(JFFS2_ACL_VERSION);
	e = header + 1;
	for (i=0; i < acl->a_count; i++) {
		entry = e;
		entry->e_tag = cpu_to_je16(acl->a_entries[i].e_tag);
		entry->e_perm = cpu_to_je16(acl->a_entries[i].e_perm);
		switch(acl->a_entries[i].e_tag) {
			case ACL_USER:
			case ACL_GROUP:
				entry->e_id = cpu_to_je32(acl->a_entries[i].e_id);
				e += sizeof(struct jffs2_acl_entry);
				break;

			case ACL_USER_OBJ:
			case ACL_GROUP_OBJ:
			case ACL_MASK:
			case ACL_OTHER:
				e += sizeof(struct jffs2_acl_entry_short);
				break;

			default:
				goto fail;
		}
	}
	return header;
 fail:
	kfree(header);
	return ERR_PTR(-EINVAL);
}

static struct posix_acl *jffs2_iget_acl(struct inode *inode, struct posix_acl **i_acl)
{
	struct posix_acl *acl = ACL_NOT_CACHED;

	spin_lock(&inode->i_lock);
	if (*i_acl != ACL_NOT_CACHED)
		acl = posix_acl_dup(*i_acl);
	spin_unlock(&inode->i_lock);
	return acl;
}

static void jffs2_iset_acl(struct inode *inode, struct posix_acl **i_acl, struct posix_acl *acl)
{
	spin_lock(&inode->i_lock);
	if (*i_acl != ACL_NOT_CACHED)
		posix_acl_release(*i_acl);
	*i_acl = posix_acl_dup(acl);
	spin_unlock(&inode->i_lock);
}

static struct posix_acl *jffs2_get_acl(struct inode *inode, int type)
{
	struct posix_acl *acl;
	char *value = NULL;
	int rc, xprefix;

	switch (type) {
	case ACL_TYPE_ACCESS:
		acl = jffs2_iget_acl(inode, &inode->i_acl);
		if (acl != ACL_NOT_CACHED)
			return acl;
		xprefix = JFFS2_XPREFIX_ACL_ACCESS;
		break;
	case ACL_TYPE_DEFAULT:
		acl = jffs2_iget_acl(inode, &inode->i_default_acl);
		if (acl != ACL_NOT_CACHED)
			return acl;
		xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
		break;
	default:
		return ERR_PTR(-EINVAL);
	}
	rc = do_jffs2_getxattr(inode, xprefix, "", NULL, 0);
	if (rc > 0) {
		value = kmalloc(rc, GFP_KERNEL);
		if (!value)
			return ERR_PTR(-ENOMEM);
		rc = do_jffs2_getxattr(inode, xprefix, "", value, rc);
	}
	if (rc > 0) {
		acl = jffs2_acl_from_medium(value, rc);
	} else if (rc == -ENODATA || rc == -ENOSYS) {
		acl = NULL;
	} else {
		acl = ERR_PTR(rc);
	}
	if (value)
		kfree(value);
	if (!IS_ERR(acl)) {
		switch (type) {
		case ACL_TYPE_ACCESS:
			jffs2_iset_acl(inode, &inode->i_acl, acl);
			break;
		case ACL_TYPE_DEFAULT:
			jffs2_iset_acl(inode, &inode->i_default_acl, acl);
			break;
		}
	}
	return acl;
}

static int __jffs2_set_acl(struct inode *inode, int xprefix, struct posix_acl *acl)
{
	char *value = NULL;
	size_t size = 0;
	int rc;

	if (acl) {
		value = jffs2_acl_to_medium(acl, &size);
		if (IS_ERR(value))
			return PTR_ERR(value);
	}
	rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0);
	if (!value && rc == -ENODATA)
		rc = 0;
	kfree(value);

	return rc;
}

static int jffs2_set_acl(struct inode *inode, int type, struct posix_acl *acl)
{
	int rc, xprefix;

	if (S_ISLNK(inode->i_mode))
		return -EOPNOTSUPP;

	switch (type) {
	case ACL_TYPE_ACCESS:
		xprefix = JFFS2_XPREFIX_ACL_ACCESS;
		if (acl) {
			mode_t mode = inode->i_mode;
			rc = posix_acl_equiv_mode(acl, &mode);
			if (rc < 0)
				return rc;
			if (inode->i_mode != mode) {
				struct iattr attr;

				attr.ia_valid = ATTR_MODE;
				attr.ia_mode = mode;
				rc = jffs2_do_setattr(inode, &attr);
				if (rc < 0)
					return rc;
			}
			if (rc == 0)
				acl = NULL;
		}
		break;
	case ACL_TYPE_DEFAULT:
		xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
		if (!S_ISDIR(inode->i_mode))
			return acl ? -EACCES : 0;
		break;
	default:
		return -EINVAL;
	}
	rc = __jffs2_set_acl(inode, xprefix, acl);
	if (!rc) {
		switch(type) {
		case ACL_TYPE_ACCESS:
			jffs2_iset_acl(inode, &inode->i_acl, acl);
			break;
		case ACL_TYPE_DEFAULT:
			jffs2_iset_acl(inode, &inode->i_default_acl, acl);
			break;
		}
	}
	return rc;
}

static int jffs2_check_acl(struct inode *inode, int mask)
{
	struct posix_acl *acl;
	int rc;

	acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (acl) {
		rc = posix_acl_permission(inode, acl, mask);
		posix_acl_release(acl);
		return rc;
	}
	return -EAGAIN;
}

int jffs2_permission(struct inode *inode, int mask)
{
	return generic_permission(inode, mask, jffs2_check_acl);
}

int jffs2_init_acl_pre(struct inode *dir_i, struct inode *inode, int *i_mode)
{
	struct posix_acl *acl, *clone;
	int rc;

	inode->i_default_acl = NULL;
	inode->i_acl = NULL;

	if (S_ISLNK(*i_mode))
		return 0;	/* Symlink always has no-ACL */

	acl = jffs2_get_acl(dir_i, ACL_TYPE_DEFAULT);
	if (IS_ERR(acl))
		return PTR_ERR(acl);

	if (!acl) {
		*i_mode &= ~current_umask();
	} else {
		if (S_ISDIR(*i_mode))
			jffs2_iset_acl(inode, &inode->i_default_acl, acl);

		clone = posix_acl_clone(acl, GFP_KERNEL);
		if (!clone)
			return -ENOMEM;
		rc = posix_acl_create_masq(clone, (mode_t *)i_mode);
		if (rc < 0) {
			posix_acl_release(clone);
			return rc;
		}
		if (rc > 0)
			jffs2_iset_acl(inode, &inode->i_acl, clone);

		posix_acl_release(clone);
	}
	return 0;
}

int jffs2_init_acl_post(struct inode *inode)
{
	int rc;

	if (inode->i_default_acl) {
		rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_DEFAULT, inode->i_default_acl);
		if (rc)
			return rc;
	}

	if (inode->i_acl) {
		rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_ACCESS, inode->i_acl);
		if (rc)
			return rc;
	}

	return 0;
}

int jffs2_acl_chmod(struct inode *inode)
{
	struct posix_acl *acl, *clone;
	int rc;

	if (S_ISLNK(inode->i_mode))
		return -EOPNOTSUPP;
	acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
	if (IS_ERR(acl) || !acl)
		return PTR_ERR(acl);
	clone = posix_acl_clone(acl, GFP_KERNEL);
	posix_acl_release(acl);
	if (!clone)
		return -ENOMEM;
	rc = posix_acl_chmod_masq(clone, inode->i_mode);
	if (!rc)
		rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone);
	posix_acl_release(clone);
	return rc;
}

static size_t jffs2_acl_access_listxattr(struct inode *inode, char *list, size_t list_size,
					 const char *name, size_t name_len)
{
	const int retlen = sizeof(POSIX_ACL_XATTR_ACCESS);

	if (list && retlen <= list_size)
		strcpy(list, POSIX_ACL_XATTR_ACCESS);
	return retlen;
}

static size_t jffs2_acl_default_listxattr(struct inode *inode, char *list, size_t list_size,
					  const char *name, size_t name_len)
{
	const int retlen = sizeof(POSIX_ACL_XATTR_DEFAULT);

	if (list && retlen <= list_size)
		strcpy(list, POSIX_ACL_XATTR_DEFAULT);
	return retlen;
}

static int jffs2_acl_getxattr(struct inode *inode, int type, void *buffer, size_t size)
{
	struct posix_acl *acl;
	int rc;

	acl = jffs2_get_acl(inode, type);
	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (!acl)
		return -ENODATA;
	rc = posix_acl_to_xattr(acl, buffer, size);
	posix_acl_release(acl);

	return rc;
}

static int jffs2_acl_access_getxattr(struct inode *inode, const char *name, void *buffer, size_t size)
{
	if (name[0] != '\0')
		return -EINVAL;
	return jffs2_acl_getxattr(inode, ACL_TYPE_ACCESS, buffer, size);
}

static int jffs2_acl_default_getxattr(struct inode *inode, const char *name, void *buffer, size_t size)
{
	if (name[0] != '\0')
		return -EINVAL;
	return jffs2_acl_getxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
}

static int jffs2_acl_setxattr(struct inode *inode, int type, const void *value, size_t size)
{
	struct posix_acl *acl;
	int rc;

	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) {
			rc = posix_acl_valid(acl);
			if (rc)
				goto out;
		}
	} else {
		acl = NULL;
	}
	rc = jffs2_set_acl(inode, type, acl);
 out:
	posix_acl_release(acl);
	return rc;
}

static int jffs2_acl_access_setxattr(struct inode *inode, const char *name,
				     const void *buffer, size_t size, int flags)
{
	if (name[0] != '\0')
		return -EINVAL;
	return jffs2_acl_setxattr(inode, ACL_TYPE_ACCESS, buffer, size);
}

static int jffs2_acl_default_setxattr(struct inode *inode, const char *name,
				      const void *buffer, size_t size, int flags)
{
	if (name[0] != '\0')
		return -EINVAL;
	return jffs2_acl_setxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
}

struct xattr_handler jffs2_acl_access_xattr_handler = {
	.prefix	= POSIX_ACL_XATTR_ACCESS,
	.list	= jffs2_acl_access_listxattr,
	.get	= jffs2_acl_access_getxattr,
	.set	= jffs2_acl_access_setxattr,
};

struct xattr_handler jffs2_acl_default_xattr_handler = {
	.prefix	= POSIX_ACL_XATTR_DEFAULT,
	.list	= jffs2_acl_default_listxattr,
	.get	= jffs2_acl_default_getxattr,
	.set	= jffs2_acl_default_setxattr,
};
Commit	Line	Data
652ecc20 KK	1	/*
652ecc20 KK	2	* JFFS2 -- Journalling Flash File System, Version 2.
aa98d7cf	3	*
c00c310e	4	* Copyright © 2006 NEC Corporation
aa98d7cf	5	*
652ecc20 KK	6	* Created by KaiGai Kohei <kaigai@ak.jp.nec.com>
	7	*
	8	* For licensing information, see the file 'LICENCE' in this directory.
	9	*
	10	*/
c00c310e	11
aa98d7cf KK	12	#include <linux/kernel.h>
	13	#include <linux/slab.h>
	14	#include <linux/fs.h>
914e2637	15	#include <linux/sched.h>
aa98d7cf KK	16	#include <linux/time.h>
	17	#include <linux/crc32.h>
	18	#include <linux/jffs2.h>
	19	#include <linux/xattr.h>
	20	#include <linux/posix_acl_xattr.h>
	21	#include <linux/mtd/mtd.h>
	22	#include "nodelist.h"
	23
	24	static size_t jffs2_acl_size(int count)
	25	{
	26	if (count <= 4) {
de1f72fa KK	27	return sizeof(struct jffs2_acl_header)
de1f72fa KK	28	+ count * sizeof(struct jffs2_acl_entry_short);
aa98d7cf	29	} else {
de1f72fa KK	30	return sizeof(struct jffs2_acl_header)
	31	+ 4 * sizeof(struct jffs2_acl_entry_short)
	32	+ (count - 4) * sizeof(struct jffs2_acl_entry);
aa98d7cf KK	33	}
	34	}
	35
	36	static int jffs2_acl_count(size_t size)
	37	{
	38	size_t s;
	39
de1f72fa	40	size -= sizeof(struct jffs2_acl_header);
fc371a25	41	if (size < 4 * sizeof(struct jffs2_acl_entry_short)) {
de1f72fa	42	if (size % sizeof(struct jffs2_acl_entry_short))
aa98d7cf	43	return -1;
de1f72fa	44	return size / sizeof(struct jffs2_acl_entry_short);
aa98d7cf	45	} else {
fc371a25	46	s = size - 4 * sizeof(struct jffs2_acl_entry_short);
de1f72fa	47	if (s % sizeof(struct jffs2_acl_entry))
aa98d7cf	48	return -1;
de1f72fa	49	return s / sizeof(struct jffs2_acl_entry) + 4;
aa98d7cf KK	50	}
	51	}
	52
dea80134	53	static struct posix_acl jffs2_acl_from_medium(void value, size_t size)
aa98d7cf	54	{
dea80134 KK	55	void *end = value + size;
	56	struct jffs2_acl_header *header = value;
	57	struct jffs2_acl_entry *entry;
aa98d7cf KK	58	struct posix_acl *acl;
	59	uint32_t ver;
	60	int i, count;
	61
	62	if (!value)
	63	return NULL;
de1f72fa	64	if (size < sizeof(struct jffs2_acl_header))
aa98d7cf	65	return ERR_PTR(-EINVAL);
dea80134	66	ver = je32_to_cpu(header->a_version);
aa98d7cf KK	67	if (ver != JFFS2_ACL_VERSION) {
	68	JFFS2_WARNING("Invalid ACL version. (=%u)\n", ver);
	69	return ERR_PTR(-EINVAL);
	70	}
	71
dea80134	72	value += sizeof(struct jffs2_acl_header);
aa98d7cf KK	73	count = jffs2_acl_count(size);
	74	if (count < 0)
	75	return ERR_PTR(-EINVAL);
	76	if (count == 0)
	77	return NULL;
	78
	79	acl = posix_acl_alloc(count, GFP_KERNEL);
	80	if (!acl)
	81	return ERR_PTR(-ENOMEM);
	82
	83	for (i=0; i < count; i++) {
dea80134 KK	84	entry = value;
dea80134 KK	85	if (value + sizeof(struct jffs2_acl_entry_short) > end)
aa98d7cf KK	86	goto fail;
	87	acl->a_entries[i].e_tag = je16_to_cpu(entry->e_tag);
	88	acl->a_entries[i].e_perm = je16_to_cpu(entry->e_perm);
	89	switch (acl->a_entries[i].e_tag) {
	90	case ACL_USER_OBJ:
	91	case ACL_GROUP_OBJ:
	92	case ACL_MASK:
	93	case ACL_OTHER:
dea80134	94	value += sizeof(struct jffs2_acl_entry_short);
aa98d7cf KK	95	acl->a_entries[i].e_id = ACL_UNDEFINED_ID;
	96	break;
	97
	98	case ACL_USER:
	99	case ACL_GROUP:
dea80134 KK	100	value += sizeof(struct jffs2_acl_entry);
dea80134 KK	101	if (value > end)
aa98d7cf KK	102	goto fail;
	103	acl->a_entries[i].e_id = je32_to_cpu(entry->e_id);
	104	break;
	105
	106	default:
	107	goto fail;
	108	}
	109	}
	110	if (value != end)
	111	goto fail;
	112	return acl;
	113	fail:
	114	posix_acl_release(acl);
	115	return ERR_PTR(-EINVAL);
	116	}
	117
	118	static void jffs2_acl_to_medium(const struct posix_acl acl, size_t *size)
	119	{
dea80134 KK	120	struct jffs2_acl_header *header;
	121	struct jffs2_acl_entry *entry;
	122	void *e;
aa98d7cf KK	123	size_t i;
	124
	125	*size = jffs2_acl_size(acl->a_count);
dea80134 KK	126	header = kmalloc(sizeof(header) + acl->a_count sizeof(*entry), GFP_KERNEL);
dea80134 KK	127	if (!header)
aa98d7cf	128	return ERR_PTR(-ENOMEM);
dea80134 KK	129	header->a_version = cpu_to_je32(JFFS2_ACL_VERSION);
dea80134 KK	130	e = header + 1;
aa98d7cf	131	for (i=0; i < acl->a_count; i++) {
dea80134	132	entry = e;
aa98d7cf KK	133	entry->e_tag = cpu_to_je16(acl->a_entries[i].e_tag);
	134	entry->e_perm = cpu_to_je16(acl->a_entries[i].e_perm);
	135	switch(acl->a_entries[i].e_tag) {
	136	case ACL_USER:
	137	case ACL_GROUP:
	138	entry->e_id = cpu_to_je32(acl->a_entries[i].e_id);
de1f72fa	139	e += sizeof(struct jffs2_acl_entry);
aa98d7cf KK	140	break;
	141
	142	case ACL_USER_OBJ:
	143	case ACL_GROUP_OBJ:
	144	case ACL_MASK:
	145	case ACL_OTHER:
de1f72fa	146	e += sizeof(struct jffs2_acl_entry_short);
aa98d7cf KK	147	break;
	148
	149	default:
	150	goto fail;
	151	}
	152	}
dea80134	153	return header;
aa98d7cf	154	fail:
dea80134	155	kfree(header);
aa98d7cf KK	156	return ERR_PTR(-EINVAL);
	157	}
	158
	159	static struct posix_acl jffs2_iget_acl(struct inode inode, struct posix_acl **i_acl)
	160	{
290c263b	161	struct posix_acl *acl = ACL_NOT_CACHED;
aa98d7cf KK	162
aa98d7cf KK	163	spin_lock(&inode->i_lock);
290c263b	164	if (*i_acl != ACL_NOT_CACHED)
aa98d7cf KK	165	acl = posix_acl_dup(*i_acl);
	166	spin_unlock(&inode->i_lock);
	167	return acl;
	168	}
	169
	170	static void jffs2_iset_acl(struct inode inode, struct posix_acl i_acl, struct posix_acl acl)
	171	{
	172	spin_lock(&inode->i_lock);
290c263b	173	if (*i_acl != ACL_NOT_CACHED)
aa98d7cf KK	174	posix_acl_release(*i_acl);
	175	*i_acl = posix_acl_dup(acl);
	176	spin_unlock(&inode->i_lock);
	177	}
	178
050416e9	179	static struct posix_acl jffs2_get_acl(struct inode inode, int type)
aa98d7cf	180	{
aa98d7cf KK	181	struct posix_acl *acl;
	182	char *value = NULL;
	183	int rc, xprefix;
	184
	185	switch (type) {
	186	case ACL_TYPE_ACCESS:
290c263b AV	187	acl = jffs2_iget_acl(inode, &inode->i_acl);
290c263b AV	188	if (acl != ACL_NOT_CACHED)
aa98d7cf KK	189	return acl;
	190	xprefix = JFFS2_XPREFIX_ACL_ACCESS;
	191	break;
	192	case ACL_TYPE_DEFAULT:
290c263b AV	193	acl = jffs2_iget_acl(inode, &inode->i_default_acl);
290c263b AV	194	if (acl != ACL_NOT_CACHED)
aa98d7cf KK	195	return acl;
	196	xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
	197	break;
	198	default:
	199	return ERR_PTR(-EINVAL);
	200	}
	201	rc = do_jffs2_getxattr(inode, xprefix, "", NULL, 0);
	202	if (rc > 0) {
	203	value = kmalloc(rc, GFP_KERNEL);
	204	if (!value)
	205	return ERR_PTR(-ENOMEM);
	206	rc = do_jffs2_getxattr(inode, xprefix, "", value, rc);
	207	}
	208	if (rc > 0) {
	209	acl = jffs2_acl_from_medium(value, rc);
	210	} else if (rc == -ENODATA \|\| rc == -ENOSYS) {
	211	acl = NULL;
	212	} else {
	213	acl = ERR_PTR(rc);
	214	}
	215	if (value)
	216	kfree(value);
	217	if (!IS_ERR(acl)) {
	218	switch (type) {
	219	case ACL_TYPE_ACCESS:
290c263b	220	jffs2_iset_acl(inode, &inode->i_acl, acl);
aa98d7cf KK	221	break;
aa98d7cf KK	222	case ACL_TYPE_DEFAULT:
290c263b	223	jffs2_iset_acl(inode, &inode->i_default_acl, acl);
aa98d7cf KK	224	break;
	225	}
	226	}
	227	return acl;
	228	}
	229
cfc8dc6f KK	230	static int __jffs2_set_acl(struct inode inode, int xprefix, struct posix_acl acl)
	231	{
	232	char *value = NULL;
	233	size_t size = 0;
	234	int rc;
	235
	236	if (acl) {
	237	value = jffs2_acl_to_medium(acl, &size);
	238	if (IS_ERR(value))
	239	return PTR_ERR(value);
	240	}
	241	rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0);
	242	if (!value && rc == -ENODATA)
	243	rc = 0;
	244	kfree(value);
	245
	246	return rc;
	247	}
	248
aa98d7cf KK	249	static int jffs2_set_acl(struct inode inode, int type, struct posix_acl acl)
aa98d7cf KK	250	{
aa98d7cf KK	251	int rc, xprefix;
	252
	253	if (S_ISLNK(inode->i_mode))
	254	return -EOPNOTSUPP;
	255
	256	switch (type) {
	257	case ACL_TYPE_ACCESS:
	258	xprefix = JFFS2_XPREFIX_ACL_ACCESS;
	259	if (acl) {
	260	mode_t mode = inode->i_mode;
	261	rc = posix_acl_equiv_mode(acl, &mode);
	262	if (rc < 0)
	263	return rc;
	264	if (inode->i_mode != mode) {
9ed437c5 DW	265	struct iattr attr;
	266
	267	attr.ia_valid = ATTR_MODE;
	268	attr.ia_mode = mode;
	269	rc = jffs2_do_setattr(inode, &attr);
	270	if (rc < 0)
	271	return rc;
aa98d7cf KK	272	}
	273	if (rc == 0)
	274	acl = NULL;
	275	}
	276	break;
	277	case ACL_TYPE_DEFAULT:
	278	xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
	279	if (!S_ISDIR(inode->i_mode))
	280	return acl ? -EACCES : 0;
	281	break;
	282	default:
	283	return -EINVAL;
	284	}
cfc8dc6f	285	rc = __jffs2_set_acl(inode, xprefix, acl);
aa98d7cf KK	286	if (!rc) {
	287	switch(type) {
	288	case ACL_TYPE_ACCESS:
290c263b	289	jffs2_iset_acl(inode, &inode->i_acl, acl);
aa98d7cf KK	290	break;
aa98d7cf KK	291	case ACL_TYPE_DEFAULT:
290c263b	292	jffs2_iset_acl(inode, &inode->i_default_acl, acl);
aa98d7cf KK	293	break;
	294	}
	295	}
	296	return rc;
	297	}
	298
	299	static int jffs2_check_acl(struct inode *inode, int mask)
	300	{
	301	struct posix_acl *acl;
	302	int rc;
	303
	304	acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
	305	if (IS_ERR(acl))
	306	return PTR_ERR(acl);
	307	if (acl) {
	308	rc = posix_acl_permission(inode, acl, mask);
	309	posix_acl_release(acl);
	310	return rc;
	311	}
	312	return -EAGAIN;
	313	}
	314
e6305c43	315	int jffs2_permission(struct inode *inode, int mask)
aa98d7cf KK	316	{
	317	return generic_permission(inode, mask, jffs2_check_acl);
	318	}
	319
cfc8dc6f	320	int jffs2_init_acl_pre(struct inode dir_i, struct inode inode, int *i_mode)
aa98d7cf	321	{
cfc8dc6f KK	322	struct posix_acl acl, clone;
cfc8dc6f KK	323	int rc;
aa98d7cf	324
290c263b AV	325	inode->i_default_acl = NULL;
290c263b AV	326	inode->i_acl = NULL;
cfc8dc6f KK	327
	328	if (S_ISLNK(*i_mode))
	329	return 0; /* Symlink always has no-ACL */
	330
	331	acl = jffs2_get_acl(dir_i, ACL_TYPE_DEFAULT);
	332	if (IS_ERR(acl))
	333	return PTR_ERR(acl);
	334
	335	if (!acl) {
ce3b0f8d	336	*i_mode &= ~current_umask();
cfc8dc6f KK	337	} else {
cfc8dc6f KK	338	if (S_ISDIR(*i_mode))
290c263b	339	jffs2_iset_acl(inode, &inode->i_default_acl, acl);
9ed437c5	340
aa98d7cf	341	clone = posix_acl_clone(acl, GFP_KERNEL);
aa98d7cf	342	if (!clone)
cfc8dc6f KK	343	return -ENOMEM;
cfc8dc6f KK	344	rc = posix_acl_create_masq(clone, (mode_t *)i_mode);
36f97bc6 JL	345	if (rc < 0) {
36f97bc6 JL	346	posix_acl_release(clone);
cfc8dc6f	347	return rc;
36f97bc6	348	}
cfc8dc6f	349	if (rc > 0)
290c263b	350	jffs2_iset_acl(inode, &inode->i_acl, clone);
cfc8dc6f	351
aa98d7cf KK	352	posix_acl_release(clone);
aa98d7cf KK	353	}
cfc8dc6f KK	354	return 0;
	355	}
	356
	357	int jffs2_init_acl_post(struct inode *inode)
	358	{
cfc8dc6f KK	359	int rc;
cfc8dc6f KK	360
290c263b AV	361	if (inode->i_default_acl) {
290c263b AV	362	rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_DEFAULT, inode->i_default_acl);
cfc8dc6f KK	363	if (rc)
	364	return rc;
	365	}
	366
290c263b AV	367	if (inode->i_acl) {
290c263b AV	368	rc = __jffs2_set_acl(inode, JFFS2_XPREFIX_ACL_ACCESS, inode->i_acl);
cfc8dc6f KK	369	if (rc)
	370	return rc;
	371	}
	372
8d6ea587	373	return 0;
aa98d7cf KK	374	}
aa98d7cf KK	375
aa98d7cf KK	376	int jffs2_acl_chmod(struct inode *inode)
	377	{
	378	struct posix_acl acl, clone;
	379	int rc;
	380
	381	if (S_ISLNK(inode->i_mode))
	382	return -EOPNOTSUPP;
	383	acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
	384	if (IS_ERR(acl) \|\| !acl)
	385	return PTR_ERR(acl);
	386	clone = posix_acl_clone(acl, GFP_KERNEL);
	387	posix_acl_release(acl);
	388	if (!clone)
	389	return -ENOMEM;
	390	rc = posix_acl_chmod_masq(clone, inode->i_mode);
	391	if (!rc)
	392	rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone);
	393	posix_acl_release(clone);
	394	return rc;
	395	}
	396
	397	static size_t jffs2_acl_access_listxattr(struct inode inode, char list, size_t list_size,
	398	const char *name, size_t name_len)
	399	{
	400	const int retlen = sizeof(POSIX_ACL_XATTR_ACCESS);
	401
	402	if (list && retlen <= list_size)
	403	strcpy(list, POSIX_ACL_XATTR_ACCESS);
	404	return retlen;
	405	}
	406
	407	static size_t jffs2_acl_default_listxattr(struct inode inode, char list, size_t list_size,
	408	const char *name, size_t name_len)
	409	{
	410	const int retlen = sizeof(POSIX_ACL_XATTR_DEFAULT);
	411
	412	if (list && retlen <= list_size)
	413	strcpy(list, POSIX_ACL_XATTR_DEFAULT);
	414	return retlen;
	415	}
	416
	417	static int jffs2_acl_getxattr(struct inode inode, int type, void buffer, size_t size)
	418	{
	419	struct posix_acl *acl;
	420	int rc;
	421
	422	acl = jffs2_get_acl(inode, type);
	423	if (IS_ERR(acl))
	424	return PTR_ERR(acl);
	425	if (!acl)
	426	return -ENODATA;
	427	rc = posix_acl_to_xattr(acl, buffer, size);
	428	posix_acl_release(acl);
	429
	430	return rc;
	431	}
	432
	433	static int jffs2_acl_access_getxattr(struct inode inode, const char name, void *buffer, size_t size)
	434	{
	435	if (name[0] != '\0')
	436	return -EINVAL;
	437	return jffs2_acl_getxattr(inode, ACL_TYPE_ACCESS, buffer, size);
	438	}
	439
440	static int jffs2_acl_default_getxattr(struct inode inode, const char name, void *buffer, size_t size)
441	{
442	if (name[0] != '\0')
443	return -EINVAL;
444	return jffs2_acl_getxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
445	}
446
447	static int jffs2_acl_setxattr(struct inode inode, int type, const void value, size_t size)
448	{
449	struct posix_acl *acl;
450	int rc;
451
3bd858ab	452	if (!is_owner_or_cap(inode))
aa98d7cf KK	453	return -EPERM;
	454
	455	if (value) {
	456	acl = posix_acl_from_xattr(value, size);
	457	if (IS_ERR(acl))
	458	return PTR_ERR(acl);
	459	if (acl) {
	460	rc = posix_acl_valid(acl);
	461	if (rc)
	462	goto out;
	463	}
	464	} else {
	465	acl = NULL;
	466	}
	467	rc = jffs2_set_acl(inode, type, acl);
	468	out:
	469	posix_acl_release(acl);
	470	return rc;
	471	}
	472
	473	static int jffs2_acl_access_setxattr(struct inode inode, const char name,
	474	const void *buffer, size_t size, int flags)
	475	{
	476	if (name[0] != '\0')
	477	return -EINVAL;
	478	return jffs2_acl_setxattr(inode, ACL_TYPE_ACCESS, buffer, size);
	479	}
	480
	481	static int jffs2_acl_default_setxattr(struct inode inode, const char name,
	482	const void *buffer, size_t size, int flags)
	483	{
	484	if (name[0] != '\0')
	485	return -EINVAL;
	486	return jffs2_acl_setxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
	487	}
	488
	489	struct xattr_handler jffs2_acl_access_xattr_handler = {
	490	.prefix = POSIX_ACL_XATTR_ACCESS,
	491	.list = jffs2_acl_access_listxattr,
	492	.get = jffs2_acl_access_getxattr,
	493	.set = jffs2_acl_access_setxattr,
	494	};
	495
	496	struct xattr_handler jffs2_acl_default_xattr_handler = {
	497	.prefix = POSIX_ACL_XATTR_DEFAULT,
	498	.list = jffs2_acl_default_listxattr,
	499	.get = jffs2_acl_default_getxattr,
	500	.set = jffs2_acl_default_setxattr,
	501	};