fs/jffs2/acl.c - kernel/msm - Gitiles

 /*
  * 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);
 	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,
 };
	/*
	* 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);
	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,
	};