[linux-2.6-block.git] / fs / jffs2 / acl.c

/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright (C) 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/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);
	s = size - 4 * sizeof(struct jffs2_acl_entry_short);
	if (s < 0) {
		if (size % sizeof(struct jffs2_acl_entry_short))
			return -1;
		return size / sizeof(struct jffs2_acl_entry_short);
	} else {
		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 = JFFS2_ACL_NOT_CACHED;

	spin_lock(&inode->i_lock);
	if (*i_acl != JFFS2_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 != JFFS2_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 jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	struct posix_acl *acl;
	char *value = NULL;
	int rc, xprefix;

	switch (type) {
	case ACL_TYPE_ACCESS:
		acl = jffs2_iget_acl(inode, &f->i_acl_access);
		if (acl != JFFS2_ACL_NOT_CACHED)
			return acl;
		xprefix = JFFS2_XPREFIX_ACL_ACCESS;
		break;
	case ACL_TYPE_DEFAULT:
		acl = jffs2_iget_acl(inode, &f->i_acl_default);
		if (acl != JFFS2_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, &f->i_acl_access, acl);
			break;
		case ACL_TYPE_DEFAULT:
			jffs2_iset_acl(inode, &f->i_acl_default, acl);
			break;
		}
	}
	return acl;
}

static int jffs2_set_acl(struct inode *inode, int type, struct posix_acl *acl)
{
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	size_t size = 0;
	char *value = NULL;
	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) {
				inode->i_mode = mode;
				jffs2_dirty_inode(inode);
			}
			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;
	}
	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;
	if (value)
		kfree(value);
	if (!rc) {
		switch(type) {
		case ACL_TYPE_ACCESS:
			jffs2_iset_acl(inode, &f->i_acl_access, acl);
			break;
		case ACL_TYPE_DEFAULT:
			jffs2_iset_acl(inode, &f->i_acl_default, 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, struct nameidata *nd)
{
	return generic_permission(inode, mask, jffs2_check_acl);
}

int jffs2_init_acl(struct inode *inode, struct inode *dir)
{
	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	struct posix_acl *acl = NULL, *clone;
	mode_t mode;
	int rc = 0;

	f->i_acl_access = JFFS2_ACL_NOT_CACHED;
	f->i_acl_default = JFFS2_ACL_NOT_CACHED;
	if (!S_ISLNK(inode->i_mode)) {
		acl = jffs2_get_acl(dir, ACL_TYPE_DEFAULT);
		if (IS_ERR(acl))
			return PTR_ERR(acl);
		if (!acl)
			inode->i_mode &= ~current->fs->umask;
	}
	if (acl) {
		if (S_ISDIR(inode->i_mode)) {
			rc = jffs2_set_acl(inode, ACL_TYPE_DEFAULT, acl);
			if (rc)
				goto cleanup;
		}
		clone = posix_acl_clone(acl, GFP_KERNEL);
		rc = -ENOMEM;
		if (!clone)
			goto cleanup;
		mode = inode->i_mode;
		rc = posix_acl_create_masq(clone, &mode);
		if (rc >= 0) {
			inode->i_mode = mode;
			if (rc > 0)
				rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone);
		}
		posix_acl_release(clone);
	}
 cleanup:
	posix_acl_release(acl);
	return rc;
}

void jffs2_clear_acl(struct jffs2_inode_info *f)
{
	if (f->i_acl_access && f->i_acl_access != JFFS2_ACL_NOT_CACHED) {
		posix_acl_release(f->i_acl_access);
		f->i_acl_access = JFFS2_ACL_NOT_CACHED;
	}
	if (f->i_acl_default && f->i_acl_default != JFFS2_ACL_NOT_CACHED) {
		posix_acl_release(f->i_acl_default);
		f->i_acl_default = JFFS2_ACL_NOT_CACHED;
	}
}

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 ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
		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	*
652ecc20	4	* Copyright (C) 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	*/
aa98d7cf KK	11	#include <linux/kernel.h>
	12	#include <linux/slab.h>
	13	#include <linux/fs.h>
	14	#include <linux/time.h>
	15	#include <linux/crc32.h>
	16	#include <linux/jffs2.h>
	17	#include <linux/xattr.h>
	18	#include <linux/posix_acl_xattr.h>
	19	#include <linux/mtd/mtd.h>
	20	#include "nodelist.h"
	21
	22	static size_t jffs2_acl_size(int count)
	23	{
	24	if (count <= 4) {
de1f72fa KK	25	return sizeof(struct jffs2_acl_header)
de1f72fa KK	26	+ count * sizeof(struct jffs2_acl_entry_short);
aa98d7cf	27	} else {
de1f72fa KK	28	return sizeof(struct jffs2_acl_header)
	29	+ 4 * sizeof(struct jffs2_acl_entry_short)
	30	+ (count - 4) * sizeof(struct jffs2_acl_entry);
aa98d7cf KK	31	}
	32	}
	33
	34	static int jffs2_acl_count(size_t size)
	35	{
	36	size_t s;
	37
de1f72fa KK	38	size -= sizeof(struct jffs2_acl_header);
de1f72fa KK	39	s = size - 4 * sizeof(struct jffs2_acl_entry_short);
aa98d7cf	40	if (s < 0) {
de1f72fa	41	if (size % sizeof(struct jffs2_acl_entry_short))
aa98d7cf	42	return -1;
de1f72fa	43	return size / sizeof(struct jffs2_acl_entry_short);
aa98d7cf	44	} else {
de1f72fa	45	if (s % sizeof(struct jffs2_acl_entry))
aa98d7cf	46	return -1;
de1f72fa	47	return s / sizeof(struct jffs2_acl_entry) + 4;
aa98d7cf KK	48	}
	49	}
	50
dea80134	51	static struct posix_acl jffs2_acl_from_medium(void value, size_t size)
aa98d7cf	52	{
dea80134 KK	53	void *end = value + size;
	54	struct jffs2_acl_header *header = value;
	55	struct jffs2_acl_entry *entry;
aa98d7cf KK	56	struct posix_acl *acl;
	57	uint32_t ver;
	58	int i, count;
	59
	60	if (!value)
	61	return NULL;
de1f72fa	62	if (size < sizeof(struct jffs2_acl_header))
aa98d7cf	63	return ERR_PTR(-EINVAL);
dea80134	64	ver = je32_to_cpu(header->a_version);
aa98d7cf KK	65	if (ver != JFFS2_ACL_VERSION) {
	66	JFFS2_WARNING("Invalid ACL version. (=%u)\n", ver);
	67	return ERR_PTR(-EINVAL);
	68	}
	69
dea80134	70	value += sizeof(struct jffs2_acl_header);
aa98d7cf KK	71	count = jffs2_acl_count(size);
	72	if (count < 0)
	73	return ERR_PTR(-EINVAL);
	74	if (count == 0)
	75	return NULL;
	76
	77	acl = posix_acl_alloc(count, GFP_KERNEL);
	78	if (!acl)
	79	return ERR_PTR(-ENOMEM);
	80
	81	for (i=0; i < count; i++) {
dea80134 KK	82	entry = value;
dea80134 KK	83	if (value + sizeof(struct jffs2_acl_entry_short) > end)
aa98d7cf KK	84	goto fail;
	85	acl->a_entries[i].e_tag = je16_to_cpu(entry->e_tag);
	86	acl->a_entries[i].e_perm = je16_to_cpu(entry->e_perm);
	87	switch (acl->a_entries[i].e_tag) {
	88	case ACL_USER_OBJ:
	89	case ACL_GROUP_OBJ:
	90	case ACL_MASK:
	91	case ACL_OTHER:
dea80134	92	value += sizeof(struct jffs2_acl_entry_short);
aa98d7cf KK	93	acl->a_entries[i].e_id = ACL_UNDEFINED_ID;
	94	break;
	95
	96	case ACL_USER:
	97	case ACL_GROUP:
dea80134 KK	98	value += sizeof(struct jffs2_acl_entry);
dea80134 KK	99	if (value > end)
aa98d7cf KK	100	goto fail;
	101	acl->a_entries[i].e_id = je32_to_cpu(entry->e_id);
	102	break;
	103
	104	default:
	105	goto fail;
	106	}
	107	}
	108	if (value != end)
	109	goto fail;
	110	return acl;
	111	fail:
	112	posix_acl_release(acl);
	113	return ERR_PTR(-EINVAL);
	114	}
	115
	116	static void jffs2_acl_to_medium(const struct posix_acl acl, size_t *size)
	117	{
dea80134 KK	118	struct jffs2_acl_header *header;
	119	struct jffs2_acl_entry *entry;
	120	void *e;
aa98d7cf KK	121	size_t i;
	122
	123	*size = jffs2_acl_size(acl->a_count);
dea80134 KK	124	header = kmalloc(sizeof(header) + acl->a_count sizeof(*entry), GFP_KERNEL);
dea80134 KK	125	if (!header)
aa98d7cf	126	return ERR_PTR(-ENOMEM);
dea80134 KK	127	header->a_version = cpu_to_je32(JFFS2_ACL_VERSION);
dea80134 KK	128	e = header + 1;
aa98d7cf	129	for (i=0; i < acl->a_count; i++) {
dea80134	130	entry = e;
aa98d7cf KK	131	entry->e_tag = cpu_to_je16(acl->a_entries[i].e_tag);
	132	entry->e_perm = cpu_to_je16(acl->a_entries[i].e_perm);
	133	switch(acl->a_entries[i].e_tag) {
	134	case ACL_USER:
	135	case ACL_GROUP:
	136	entry->e_id = cpu_to_je32(acl->a_entries[i].e_id);
de1f72fa	137	e += sizeof(struct jffs2_acl_entry);
aa98d7cf KK	138	break;
	139
	140	case ACL_USER_OBJ:
	141	case ACL_GROUP_OBJ:
	142	case ACL_MASK:
	143	case ACL_OTHER:
de1f72fa	144	e += sizeof(struct jffs2_acl_entry_short);
aa98d7cf KK	145	break;
	146
	147	default:
	148	goto fail;
	149	}
	150	}
dea80134	151	return header;
aa98d7cf	152	fail:
dea80134	153	kfree(header);
aa98d7cf KK	154	return ERR_PTR(-EINVAL);
	155	}
	156
	157	static struct posix_acl jffs2_iget_acl(struct inode inode, struct posix_acl **i_acl)
	158	{
	159	struct posix_acl *acl = JFFS2_ACL_NOT_CACHED;
	160
	161	spin_lock(&inode->i_lock);
	162	if (*i_acl != JFFS2_ACL_NOT_CACHED)
	163	acl = posix_acl_dup(*i_acl);
	164	spin_unlock(&inode->i_lock);
	165	return acl;
	166	}
	167
	168	static void jffs2_iset_acl(struct inode inode, struct posix_acl i_acl, struct posix_acl acl)
	169	{
	170	spin_lock(&inode->i_lock);
	171	if (*i_acl != JFFS2_ACL_NOT_CACHED)
	172	posix_acl_release(*i_acl);
	173	*i_acl = posix_acl_dup(acl);
	174	spin_unlock(&inode->i_lock);
	175	}
	176
	177	static struct posix_acl jffs2_get_acl(struct inode inode, int type)
	178	{
	179	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	180	struct posix_acl *acl;
	181	char *value = NULL;
	182	int rc, xprefix;
	183
	184	switch (type) {
	185	case ACL_TYPE_ACCESS:
	186	acl = jffs2_iget_acl(inode, &f->i_acl_access);
	187	if (acl != JFFS2_ACL_NOT_CACHED)
	188	return acl;
	189	xprefix = JFFS2_XPREFIX_ACL_ACCESS;
	190	break;
	191	case ACL_TYPE_DEFAULT:
	192	acl = jffs2_iget_acl(inode, &f->i_acl_default);
	193	if (acl != JFFS2_ACL_NOT_CACHED)
	194	return acl;
	195	xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
	196	break;
	197	default:
	198	return ERR_PTR(-EINVAL);
	199	}
	200	rc = do_jffs2_getxattr(inode, xprefix, "", NULL, 0);
	201	if (rc > 0) {
	202	value = kmalloc(rc, GFP_KERNEL);
	203	if (!value)
	204	return ERR_PTR(-ENOMEM);
	205	rc = do_jffs2_getxattr(inode, xprefix, "", value, rc);
	206	}
	207	if (rc > 0) {
	208	acl = jffs2_acl_from_medium(value, rc);
	209	} else if (rc == -ENODATA \|\| rc == -ENOSYS) {
	210	acl = NULL;
	211	} else {
	212	acl = ERR_PTR(rc);
	213	}
	214	if (value)
	215	kfree(value);
	216	if (!IS_ERR(acl)) {
	217	switch (type) {
218	case ACL_TYPE_ACCESS:
219	jffs2_iset_acl(inode, &f->i_acl_access, acl);
220	break;
221	case ACL_TYPE_DEFAULT:
222	jffs2_iset_acl(inode, &f->i_acl_default, acl);
223	break;
224	}
225	}
226	return acl;
227	}
228
229	static int jffs2_set_acl(struct inode inode, int type, struct posix_acl acl)
230	{
231	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
232	size_t size = 0;
233	char *value = NULL;
234	int rc, xprefix;
235
236	if (S_ISLNK(inode->i_mode))
237	return -EOPNOTSUPP;
238
239	switch (type) {
240	case ACL_TYPE_ACCESS:
241	xprefix = JFFS2_XPREFIX_ACL_ACCESS;
242	if (acl) {
243	mode_t mode = inode->i_mode;
244	rc = posix_acl_equiv_mode(acl, &mode);
245	if (rc < 0)
246	return rc;
247	if (inode->i_mode != mode) {
248	inode->i_mode = mode;
249	jffs2_dirty_inode(inode);
250	}
251	if (rc == 0)
252	acl = NULL;
253	}
254	break;
255	case ACL_TYPE_DEFAULT:
256	xprefix = JFFS2_XPREFIX_ACL_DEFAULT;
257	if (!S_ISDIR(inode->i_mode))
258	return acl ? -EACCES : 0;
259	break;
260	default:
261	return -EINVAL;
262	}
263	if (acl) {
264	value = jffs2_acl_to_medium(acl, &size);
265	if (IS_ERR(value))
266	return PTR_ERR(value);
267	}
268
269	rc = do_jffs2_setxattr(inode, xprefix, "", value, size, 0);
a1ae76e9 KK	270	if (!value && rc == -ENODATA)
a1ae76e9 KK	271	rc = 0;
aa98d7cf KK	272	if (value)
	273	kfree(value);
	274	if (!rc) {
	275	switch(type) {
	276	case ACL_TYPE_ACCESS:
	277	jffs2_iset_acl(inode, &f->i_acl_access, acl);
	278	break;
	279	case ACL_TYPE_DEFAULT:
	280	jffs2_iset_acl(inode, &f->i_acl_default, acl);
	281	break;
	282	}
	283	}
	284	return rc;
	285	}
	286
	287	static int jffs2_check_acl(struct inode *inode, int mask)
	288	{
	289	struct posix_acl *acl;
	290	int rc;
	291
	292	acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
	293	if (IS_ERR(acl))
	294	return PTR_ERR(acl);
	295	if (acl) {
	296	rc = posix_acl_permission(inode, acl, mask);
	297	posix_acl_release(acl);
	298	return rc;
	299	}
	300	return -EAGAIN;
	301	}
	302
	303	int jffs2_permission(struct inode inode, int mask, struct nameidata nd)
	304	{
	305	return generic_permission(inode, mask, jffs2_check_acl);
	306	}
	307
	308	int jffs2_init_acl(struct inode inode, struct inode dir)
	309	{
	310	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
	311	struct posix_acl acl = NULL, clone;
	312	mode_t mode;
	313	int rc = 0;
	314
	315	f->i_acl_access = JFFS2_ACL_NOT_CACHED;
	316	f->i_acl_default = JFFS2_ACL_NOT_CACHED;
	317	if (!S_ISLNK(inode->i_mode)) {
	318	acl = jffs2_get_acl(dir, ACL_TYPE_DEFAULT);
	319	if (IS_ERR(acl))
	320	return PTR_ERR(acl);
	321	if (!acl)
	322	inode->i_mode &= ~current->fs->umask;
	323	}
	324	if (acl) {
	325	if (S_ISDIR(inode->i_mode)) {
	326	rc = jffs2_set_acl(inode, ACL_TYPE_DEFAULT, acl);
	327	if (rc)
	328	goto cleanup;
	329	}
	330	clone = posix_acl_clone(acl, GFP_KERNEL);
	331	rc = -ENOMEM;
	332	if (!clone)
	333	goto cleanup;
	334	mode = inode->i_mode;
	335	rc = posix_acl_create_masq(clone, &mode);
336	if (rc >= 0) {
337	inode->i_mode = mode;
338	if (rc > 0)
339	rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone);
340	}
341	posix_acl_release(clone);
342	}
343	cleanup:
344	posix_acl_release(acl);
345	return rc;
346	}
347
c7afb0f9	348	void jffs2_clear_acl(struct jffs2_inode_info *f)
aa98d7cf	349	{
aa98d7cf KK	350	if (f->i_acl_access && f->i_acl_access != JFFS2_ACL_NOT_CACHED) {
	351	posix_acl_release(f->i_acl_access);
	352	f->i_acl_access = JFFS2_ACL_NOT_CACHED;
	353	}
	354	if (f->i_acl_default && f->i_acl_default != JFFS2_ACL_NOT_CACHED) {
	355	posix_acl_release(f->i_acl_default);
	356	f->i_acl_default = JFFS2_ACL_NOT_CACHED;
	357	}
	358	}
	359
	360	int jffs2_acl_chmod(struct inode *inode)
	361	{
	362	struct posix_acl acl, clone;
	363	int rc;
	364
	365	if (S_ISLNK(inode->i_mode))
	366	return -EOPNOTSUPP;
	367	acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS);
	368	if (IS_ERR(acl) \|\| !acl)
	369	return PTR_ERR(acl);
	370	clone = posix_acl_clone(acl, GFP_KERNEL);
	371	posix_acl_release(acl);
	372	if (!clone)
	373	return -ENOMEM;
	374	rc = posix_acl_chmod_masq(clone, inode->i_mode);
	375	if (!rc)
	376	rc = jffs2_set_acl(inode, ACL_TYPE_ACCESS, clone);
	377	posix_acl_release(clone);
	378	return rc;
	379	}
	380
	381	static size_t jffs2_acl_access_listxattr(struct inode inode, char list, size_t list_size,
	382	const char *name, size_t name_len)
	383	{
	384	const int retlen = sizeof(POSIX_ACL_XATTR_ACCESS);
	385
	386	if (list && retlen <= list_size)
	387	strcpy(list, POSIX_ACL_XATTR_ACCESS);
	388	return retlen;
	389	}
	390
	391	static size_t jffs2_acl_default_listxattr(struct inode inode, char list, size_t list_size,
	392	const char *name, size_t name_len)
	393	{
	394	const int retlen = sizeof(POSIX_ACL_XATTR_DEFAULT);
	395
	396	if (list && retlen <= list_size)
	397	strcpy(list, POSIX_ACL_XATTR_DEFAULT);
	398	return retlen;
	399	}
	400
	401	static int jffs2_acl_getxattr(struct inode inode, int type, void buffer, size_t size)
	402	{
	403	struct posix_acl *acl;
	404	int rc;
	405
	406	acl = jffs2_get_acl(inode, type);
	407	if (IS_ERR(acl))
	408	return PTR_ERR(acl);
	409	if (!acl)
	410	return -ENODATA;
	411	rc = posix_acl_to_xattr(acl, buffer, size);
	412	posix_acl_release(acl);
	413
414	return rc;
415	}
416
417	static int jffs2_acl_access_getxattr(struct inode inode, const char name, void *buffer, size_t size)
418	{
419	if (name[0] != '\0')
420	return -EINVAL;
421	return jffs2_acl_getxattr(inode, ACL_TYPE_ACCESS, buffer, size);
422	}
423
424	static int jffs2_acl_default_getxattr(struct inode inode, const char name, void *buffer, size_t size)
425	{
426	if (name[0] != '\0')
427	return -EINVAL;
428	return jffs2_acl_getxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
429	}
430
431	static int jffs2_acl_setxattr(struct inode inode, int type, const void value, size_t size)
432	{
433	struct posix_acl *acl;
434	int rc;
435
436	if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
437	return -EPERM;
438
439	if (value) {
440	acl = posix_acl_from_xattr(value, size);
441	if (IS_ERR(acl))
442	return PTR_ERR(acl);
443	if (acl) {
444	rc = posix_acl_valid(acl);
445	if (rc)
446	goto out;
447	}
448	} else {
449	acl = NULL;
450	}
451	rc = jffs2_set_acl(inode, type, acl);
452	out:
453	posix_acl_release(acl);
454	return rc;
455	}
456
457	static int jffs2_acl_access_setxattr(struct inode inode, const char name,
458	const void *buffer, size_t size, int flags)
459	{
460	if (name[0] != '\0')
461	return -EINVAL;
462	return jffs2_acl_setxattr(inode, ACL_TYPE_ACCESS, buffer, size);
463	}
464
465	static int jffs2_acl_default_setxattr(struct inode inode, const char name,
466	const void *buffer, size_t size, int flags)
467	{
468	if (name[0] != '\0')
469	return -EINVAL;
470	return jffs2_acl_setxattr(inode, ACL_TYPE_DEFAULT, buffer, size);
471	}
472
473	struct xattr_handler jffs2_acl_access_xattr_handler = {
474	.prefix = POSIX_ACL_XATTR_ACCESS,
475	.list = jffs2_acl_access_listxattr,
476	.get = jffs2_acl_access_getxattr,
477	.set = jffs2_acl_access_setxattr,
478	};
479
480	struct xattr_handler jffs2_acl_default_xattr_handler = {
481	.prefix = POSIX_ACL_XATTR_DEFAULT,
482	.list = jffs2_acl_default_listxattr,
483	.get = jffs2_acl_default_getxattr,
484	.set = jffs2_acl_default_setxattr,
485	};