fs/f2fs/acl.c - maze/linux - Git at Google

 /*
  * fs/f2fs/acl.c
  *
  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
  *             http://www.samsung.com/
  *
  * Portions of this code from linux/fs/ext2/acl.c
  *
  * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
 #include <linux/f2fs_fs.h>
 #include "f2fs.h"
 #include "xattr.h"
 #include "acl.h"

 static inline size_t f2fs_acl_size(int count)
 {
 	if (count <= 4) {
 		return sizeof(struct f2fs_acl_header) +
 			count * sizeof(struct f2fs_acl_entry_short);
 	} else {
 		return sizeof(struct f2fs_acl_header) +
 			4 * sizeof(struct f2fs_acl_entry_short) +
 			(count - 4) * sizeof(struct f2fs_acl_entry);
 	}
 }

 static inline int f2fs_acl_count(size_t size)
 {
 	ssize_t s;
 	size -= sizeof(struct f2fs_acl_header);
 	s = size - 4 * sizeof(struct f2fs_acl_entry_short);
 	if (s < 0) {
 		if (size % sizeof(struct f2fs_acl_entry_short))
 			return -1;
 		return size / sizeof(struct f2fs_acl_entry_short);
 	} else {
 		if (s % sizeof(struct f2fs_acl_entry))
 			return -1;
 		return s / sizeof(struct f2fs_acl_entry) + 4;
 	}
 }

 static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size)
 {
 	int i, count;
 	struct posix_acl *acl;
 	struct f2fs_acl_header *hdr = (struct f2fs_acl_header *)value;
 	struct f2fs_acl_entry *entry = (struct f2fs_acl_entry *)(hdr + 1);
 	const char *end = value + size;

 	if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION))
 		return ERR_PTR(-EINVAL);

 	count = f2fs_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++) {

 		if ((char *)entry > end)
 			goto fail;

 		acl->a_entries[i].e_tag  = le16_to_cpu(entry->e_tag);
 		acl->a_entries[i].e_perm = le16_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:
 			entry = (struct f2fs_acl_entry *)((char *)entry +
 					sizeof(struct f2fs_acl_entry_short));
 			break;

 		case ACL_USER:
 			acl->a_entries[i].e_uid =
 				make_kuid(&init_user_ns,
 						le32_to_cpu(entry->e_id));
 			entry = (struct f2fs_acl_entry *)((char *)entry +
 					sizeof(struct f2fs_acl_entry));
 			break;
 		case ACL_GROUP:
 			acl->a_entries[i].e_gid =
 				make_kgid(&init_user_ns,
 						le32_to_cpu(entry->e_id));
 			entry = (struct f2fs_acl_entry *)((char *)entry +
 					sizeof(struct f2fs_acl_entry));
 			break;
 		default:
 			goto fail;
 		}
 	}
 	if ((char *)entry != end)
 		goto fail;
 	return acl;
 fail:
 	posix_acl_release(acl);
 	return ERR_PTR(-EINVAL);
 }

 static void *f2fs_acl_to_disk(const struct posix_acl *acl, size_t *size)
 {
 	struct f2fs_acl_header *f2fs_acl;
 	struct f2fs_acl_entry *entry;
 	int i;

 	f2fs_acl = kmalloc(sizeof(struct f2fs_acl_header) + acl->a_count *
 			sizeof(struct f2fs_acl_entry), GFP_KERNEL);
 	if (!f2fs_acl)
 		return ERR_PTR(-ENOMEM);

 	f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION);
 	entry = (struct f2fs_acl_entry *)(f2fs_acl + 1);

 	for (i = 0; i < acl->a_count; i++) {

 		entry->e_tag  = cpu_to_le16(acl->a_entries[i].e_tag);
 		entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm);

 		switch (acl->a_entries[i].e_tag) {
 		case ACL_USER:
 			entry->e_id = cpu_to_le32(
 					from_kuid(&init_user_ns,
 						acl->a_entries[i].e_uid));
 			entry = (struct f2fs_acl_entry *)((char *)entry +
 					sizeof(struct f2fs_acl_entry));
 			break;
 		case ACL_GROUP:
 			entry->e_id = cpu_to_le32(
 					from_kgid(&init_user_ns,
 						acl->a_entries[i].e_gid));
 			entry = (struct f2fs_acl_entry *)((char *)entry +
 					sizeof(struct f2fs_acl_entry));
 			break;
 		case ACL_USER_OBJ:
 		case ACL_GROUP_OBJ:
 		case ACL_MASK:
 		case ACL_OTHER:
 			entry = (struct f2fs_acl_entry *)((char *)entry +
 					sizeof(struct f2fs_acl_entry_short));
 			break;
 		default:
 			goto fail;
 		}
 	}
 	*size = f2fs_acl_size(acl->a_count);
 	return (void *)f2fs_acl;

 fail:
 	kfree(f2fs_acl);
 	return ERR_PTR(-EINVAL);
 }

 struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
 {
 	int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
 	void *value = NULL;
 	struct posix_acl *acl;
 	int retval;

 	if (type == ACL_TYPE_ACCESS)
 		name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;

 	retval = f2fs_getxattr(inode, name_index, "", NULL, 0);
 	if (retval > 0) {
 		value = kmalloc(retval, GFP_F2FS_ZERO);
 		if (!value)
 			return ERR_PTR(-ENOMEM);
 		retval = f2fs_getxattr(inode, name_index, "", value, retval);
 	}

 	if (retval > 0)
 		acl = f2fs_acl_from_disk(value, retval);
 	else if (retval == -ENODATA)
 		acl = NULL;
 	else
 		acl = ERR_PTR(retval);
 	kfree(value);

 	if (!IS_ERR(acl))
 		set_cached_acl(inode, type, acl);

 	return acl;
 }

 static int __f2fs_set_acl(struct inode *inode, int type,
 			struct posix_acl *acl, struct page *ipage)
 {
 	struct f2fs_inode_info *fi = F2FS_I(inode);
 	int name_index;
 	void *value = NULL;
 	size_t size = 0;
 	int error;

 	if (acl) {
 		error = posix_acl_valid(acl);
 		if (error < 0)
 			return error;
 	}

 	switch (type) {
 	case ACL_TYPE_ACCESS:
 		name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
 		if (acl) {
 			error = posix_acl_equiv_mode(acl, &inode->i_mode);
 			if (error < 0)
 				return error;
 			set_acl_inode(fi, inode->i_mode);
 			if (error == 0)
 				acl = NULL;
 		}
 		break;

 	case ACL_TYPE_DEFAULT:
 		name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
 		if (!S_ISDIR(inode->i_mode))
 			return acl ? -EACCES : 0;
 		break;

 	default:
 		return -EINVAL;
 	}

 	if (acl) {
 		value = f2fs_acl_to_disk(acl, &size);
 		if (IS_ERR(value)) {
 			cond_clear_inode_flag(fi, FI_ACL_MODE);
 			return (int)PTR_ERR(value);
 		}
 	}

 	error = f2fs_setxattr(inode, name_index, "", value, size, ipage);

 	kfree(value);
 	if (!error)
 		set_cached_acl(inode, type, acl);

 	cond_clear_inode_flag(fi, FI_ACL_MODE);
 	return error;
 }

 int f2fs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 {
 	return __f2fs_set_acl(inode, type, acl, NULL);
 }

 int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage)
 {
 	struct posix_acl *default_acl, *acl;
 	int error = 0;

 	error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
 	if (error)
 		return error;

 	if (default_acl) {
 		error = __f2fs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl,
 				       ipage);
 		posix_acl_release(default_acl);
 	}
 	if (acl) {
 		if (error)
 			error = __f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl,
 					       ipage);
 		posix_acl_release(acl);
 	}

 	return error;
 }
	/*
	* fs/f2fs/acl.c
	*
	* Copyright (c) 2012 Samsung Electronics Co., Ltd.
	* http://www.samsung.com/
	*
	* Portions of this code from linux/fs/ext2/acl.c
	*
	* Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/
	#include <linux/f2fs_fs.h>
	#include "f2fs.h"
	#include "xattr.h"
	#include "acl.h"

	static inline size_t f2fs_acl_size(int count)
	{
	if (count <= 4) {
	return sizeof(struct f2fs_acl_header) +
	count * sizeof(struct f2fs_acl_entry_short);
	} else {
	return sizeof(struct f2fs_acl_header) +
	4 * sizeof(struct f2fs_acl_entry_short) +
	(count - 4) * sizeof(struct f2fs_acl_entry);
	}
	}

	static inline int f2fs_acl_count(size_t size)
	{
	ssize_t s;
	size -= sizeof(struct f2fs_acl_header);
	s = size - 4 * sizeof(struct f2fs_acl_entry_short);
	if (s < 0) {
	if (size % sizeof(struct f2fs_acl_entry_short))
	return -1;
	return size / sizeof(struct f2fs_acl_entry_short);
	} else {
	if (s % sizeof(struct f2fs_acl_entry))
	return -1;
	return s / sizeof(struct f2fs_acl_entry) + 4;
	}
	}

	static struct posix_acl f2fs_acl_from_disk(const char value, size_t size)
	{
	int i, count;
	struct posix_acl *acl;
	struct f2fs_acl_header hdr = (struct f2fs_acl_header )value;
	struct f2fs_acl_entry entry = (struct f2fs_acl_entry )(hdr + 1);
	const char *end = value + size;

	if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION))
	return ERR_PTR(-EINVAL);

	count = f2fs_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++) {

	if ((char *)entry > end)
	goto fail;

	acl->a_entries[i].e_tag = le16_to_cpu(entry->e_tag);
	acl->a_entries[i].e_perm = le16_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:
	entry = (struct f2fs_acl_entry )((char )entry +
	sizeof(struct f2fs_acl_entry_short));
	break;

	case ACL_USER:
	acl->a_entries[i].e_uid =
	make_kuid(&init_user_ns,
	le32_to_cpu(entry->e_id));
	entry = (struct f2fs_acl_entry )((char )entry +
	sizeof(struct f2fs_acl_entry));
	break;
	case ACL_GROUP:
	acl->a_entries[i].e_gid =
	make_kgid(&init_user_ns,
	le32_to_cpu(entry->e_id));
	entry = (struct f2fs_acl_entry )((char )entry +
	sizeof(struct f2fs_acl_entry));
	break;
	default:
	goto fail;
	}
	}
	if ((char *)entry != end)
	goto fail;
	return acl;
	fail:
	posix_acl_release(acl);
	return ERR_PTR(-EINVAL);
	}

	static void f2fs_acl_to_disk(const struct posix_acl acl, size_t *size)
	{
	struct f2fs_acl_header *f2fs_acl;
	struct f2fs_acl_entry *entry;
	int i;

	f2fs_acl = kmalloc(sizeof(struct f2fs_acl_header) + acl->a_count *
	sizeof(struct f2fs_acl_entry), GFP_KERNEL);
	if (!f2fs_acl)
	return ERR_PTR(-ENOMEM);

	f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION);
	entry = (struct f2fs_acl_entry *)(f2fs_acl + 1);

	for (i = 0; i < acl->a_count; i++) {

	entry->e_tag = cpu_to_le16(acl->a_entries[i].e_tag);
	entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm);

	switch (acl->a_entries[i].e_tag) {
	case ACL_USER:
	entry->e_id = cpu_to_le32(
	from_kuid(&init_user_ns,
	acl->a_entries[i].e_uid));
	entry = (struct f2fs_acl_entry )((char )entry +
	sizeof(struct f2fs_acl_entry));
	break;
	case ACL_GROUP:
	entry->e_id = cpu_to_le32(
	from_kgid(&init_user_ns,
	acl->a_entries[i].e_gid));
	entry = (struct f2fs_acl_entry )((char )entry +
	sizeof(struct f2fs_acl_entry));
	break;
	case ACL_USER_OBJ:
	case ACL_GROUP_OBJ:
	case ACL_MASK:
	case ACL_OTHER:
	entry = (struct f2fs_acl_entry )((char )entry +
	sizeof(struct f2fs_acl_entry_short));
	break;
	default:
	goto fail;
	}
	}
	*size = f2fs_acl_size(acl->a_count);
	return (void *)f2fs_acl;

	fail:
	kfree(f2fs_acl);
	return ERR_PTR(-EINVAL);
	}

	struct posix_acl f2fs_get_acl(struct inode inode, int type)
	{
	int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
	void *value = NULL;
	struct posix_acl *acl;
	int retval;

	if (type == ACL_TYPE_ACCESS)
	name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;

	retval = f2fs_getxattr(inode, name_index, "", NULL, 0);
	if (retval > 0) {
	value = kmalloc(retval, GFP_F2FS_ZERO);
	if (!value)
	return ERR_PTR(-ENOMEM);
	retval = f2fs_getxattr(inode, name_index, "", value, retval);
	}

	if (retval > 0)
	acl = f2fs_acl_from_disk(value, retval);
	else if (retval == -ENODATA)
	acl = NULL;
	else
	acl = ERR_PTR(retval);
	kfree(value);

	if (!IS_ERR(acl))
	set_cached_acl(inode, type, acl);

	return acl;
	}

	static int __f2fs_set_acl(struct inode *inode, int type,
	struct posix_acl acl, struct page ipage)
	{
	struct f2fs_inode_info *fi = F2FS_I(inode);
	int name_index;
	void *value = NULL;
	size_t size = 0;
	int error;

	if (acl) {
	error = posix_acl_valid(acl);
	if (error < 0)
	return error;
	}

	switch (type) {
	case ACL_TYPE_ACCESS:
	name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
	if (acl) {
	error = posix_acl_equiv_mode(acl, &inode->i_mode);
	if (error < 0)
	return error;
	set_acl_inode(fi, inode->i_mode);
	if (error == 0)
	acl = NULL;
	}
	break;

	case ACL_TYPE_DEFAULT:
	name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
	if (!S_ISDIR(inode->i_mode))
	return acl ? -EACCES : 0;
	break;

	default:
	return -EINVAL;
	}

	if (acl) {
	value = f2fs_acl_to_disk(acl, &size);
	if (IS_ERR(value)) {
	cond_clear_inode_flag(fi, FI_ACL_MODE);
	return (int)PTR_ERR(value);
	}
	}

	error = f2fs_setxattr(inode, name_index, "", value, size, ipage);

	kfree(value);
	if (!error)
	set_cached_acl(inode, type, acl);

	cond_clear_inode_flag(fi, FI_ACL_MODE);
	return error;
	}

	int f2fs_set_acl(struct inode inode, struct posix_acl acl, int type)
	{
	return __f2fs_set_acl(inode, type, acl, NULL);
	}

	int f2fs_init_acl(struct inode inode, struct inode dir, struct page *ipage)
	{
	struct posix_acl default_acl, acl;
	int error = 0;

	error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
	if (error)
	return error;

	if (default_acl) {
	error = __f2fs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl,
	ipage);
	posix_acl_release(default_acl);
	}
	if (acl) {
	if (error)
	error = __f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl,
	ipage);
	posix_acl_release(acl);
	}

	return error;
	}