[mirror_ubuntu-artful-kernel.git] / fs / ext4 / acl.c

/*
 * linux/fs/ext4/acl.c
 *
 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
 */

#include <linux/quotaops.h>
#include "ext4_jbd2.h"
#include "ext4.h"
#include "xattr.h"
#include "acl.h"

/*
 * Convert from filesystem to in-memory representation.
 */
static struct posix_acl *
ext4_acl_from_disk(const void *value, size_t size)
{
	const char *end = (char *)value + size;
	int n, count;
	struct posix_acl *acl;

	if (!value)
		return NULL;
	if (size < sizeof(ext4_acl_header))
		 return ERR_PTR(-EINVAL);
	if (((ext4_acl_header *)value)->a_version !=
	    cpu_to_le32(EXT4_ACL_VERSION))
		return ERR_PTR(-EINVAL);
	value = (char *)value + sizeof(ext4_acl_header);
	count = ext4_acl_count(size);
	if (count < 0)
		return ERR_PTR(-EINVAL);
	if (count == 0)
		return NULL;
	acl = posix_acl_alloc(count, GFP_NOFS);
	if (!acl)
		return ERR_PTR(-ENOMEM);
	for (n = 0; n < count; n++) {
		ext4_acl_entry *entry =
			(ext4_acl_entry *)value;
		if ((char *)value + sizeof(ext4_acl_entry_short) > end)
			goto fail;
		acl->a_entries[n].e_tag  = le16_to_cpu(entry->e_tag);
		acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);

		switch (acl->a_entries[n].e_tag) {
		case ACL_USER_OBJ:
		case ACL_GROUP_OBJ:
		case ACL_MASK:
		case ACL_OTHER:
			value = (char *)value +
				sizeof(ext4_acl_entry_short);
			break;

		case ACL_USER:
			value = (char *)value + sizeof(ext4_acl_entry);
			if ((char *)value > end)
				goto fail;
			acl->a_entries[n].e_uid =
				make_kuid(&init_user_ns,
					  le32_to_cpu(entry->e_id));
			break;
		case ACL_GROUP:
			value = (char *)value + sizeof(ext4_acl_entry);
			if ((char *)value > end)
				goto fail;
			acl->a_entries[n].e_gid =
				make_kgid(&init_user_ns,
					  le32_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);
}

/*
 * Convert from in-memory to filesystem representation.
 */
static void *
ext4_acl_to_disk(const struct posix_acl *acl, size_t *size)
{
	ext4_acl_header *ext_acl;
	char *e;
	size_t n;

	*size = ext4_acl_size(acl->a_count);
	ext_acl = kmalloc(sizeof(ext4_acl_header) + acl->a_count *
			sizeof(ext4_acl_entry), GFP_NOFS);
	if (!ext_acl)
		return ERR_PTR(-ENOMEM);
	ext_acl->a_version = cpu_to_le32(EXT4_ACL_VERSION);
	e = (char *)ext_acl + sizeof(ext4_acl_header);
	for (n = 0; n < acl->a_count; n++) {
		const struct posix_acl_entry *acl_e = &acl->a_entries[n];
		ext4_acl_entry *entry = (ext4_acl_entry *)e;
		entry->e_tag  = cpu_to_le16(acl_e->e_tag);
		entry->e_perm = cpu_to_le16(acl_e->e_perm);
		switch (acl_e->e_tag) {
		case ACL_USER:
			entry->e_id = cpu_to_le32(
				from_kuid(&init_user_ns, acl_e->e_uid));
			e += sizeof(ext4_acl_entry);
			break;
		case ACL_GROUP:
			entry->e_id = cpu_to_le32(
				from_kgid(&init_user_ns, acl_e->e_gid));
			e += sizeof(ext4_acl_entry);
			break;

		case ACL_USER_OBJ:
		case ACL_GROUP_OBJ:
		case ACL_MASK:
		case ACL_OTHER:
			e += sizeof(ext4_acl_entry_short);
			break;

		default:
			goto fail;
		}
	}
	return (char *)ext_acl;

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

/*
 * Inode operation get_posix_acl().
 *
 * inode->i_mutex: don't care
 */
struct posix_acl *
ext4_get_acl(struct inode *inode, int type)
{
	int name_index;
	char *value = NULL;
	struct posix_acl *acl;
	int retval;

	switch (type) {
	case ACL_TYPE_ACCESS:
		name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
		break;
	case ACL_TYPE_DEFAULT:
		name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
		break;
	default:
		BUG();
	}
	retval = ext4_xattr_get(inode, name_index, "", NULL, 0);
	if (retval > 0) {
		value = kmalloc(retval, GFP_NOFS);
		if (!value)
			return ERR_PTR(-ENOMEM);
		retval = ext4_xattr_get(inode, name_index, "", value, retval);
	}
	if (retval > 0)
		acl = ext4_acl_from_disk(value, retval);
	else if (retval == -ENODATA || retval == -ENOSYS)
		acl = NULL;
	else
		acl = ERR_PTR(retval);
	kfree(value);

	return acl;
}

/*
 * Set the access or default ACL of an inode.
 *
 * inode->i_mutex: down unless called from ext4_new_inode
 */
static int
__ext4_set_acl(handle_t *handle, struct inode *inode, int type,
	     struct posix_acl *acl, int xattr_flags)
{
	int name_index;
	void *value = NULL;
	size_t size = 0;
	int error;

	switch (type) {
	case ACL_TYPE_ACCESS:
		name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
		break;

	case ACL_TYPE_DEFAULT:
		name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
		if (!S_ISDIR(inode->i_mode))
			return acl ? -EACCES : 0;
		break;

	default:
		return -EINVAL;
	}
	if (acl) {
		value = ext4_acl_to_disk(acl, &size);
		if (IS_ERR(value))
			return (int)PTR_ERR(value);
	}

	error = ext4_xattr_set_handle(handle, inode, name_index, "",
				      value, size, xattr_flags);

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

	return error;
}

int
ext4_set_acl(struct inode *inode, struct posix_acl *acl, int type)
{
	handle_t *handle;
	int error, credits, retries = 0;
	size_t acl_size = acl ? ext4_acl_size(acl->a_count) : 0;
	umode_t mode = inode->i_mode;
	int update_mode = 0;

	error = dquot_initialize(inode);
	if (error)
		return error;
retry:
	error = ext4_xattr_set_credits(inode, acl_size, false /* is_create */,
				       &credits);
	if (error)
		return error;

	handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
	if (IS_ERR(handle))
		return PTR_ERR(handle);

	if ((type == ACL_TYPE_ACCESS) && acl) {
		error = posix_acl_update_mode(inode, &mode, &acl);
		if (error)
			goto out_stop;
		update_mode = 1;
	}

	error = __ext4_set_acl(handle, inode, type, acl, 0 /* xattr_flags */);
	if (!error && update_mode) {
		inode->i_mode = mode;
		inode->i_ctime = current_time(inode);
		ext4_mark_inode_dirty(handle, inode);
	}
out_stop:
	ext4_journal_stop(handle);
	if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
		goto retry;
	return error;
}

/*
 * Initialize the ACLs of a new inode. Called from ext4_new_inode.
 *
 * dir->i_mutex: down
 * inode->i_mutex: up (access to inode is still exclusive)
 */
int
ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
{
	struct posix_acl *default_acl, *acl;
	int error;

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

	if (default_acl) {
		error = __ext4_set_acl(handle, inode, ACL_TYPE_DEFAULT,
				       default_acl, XATTR_CREATE);
		posix_acl_release(default_acl);
	}
	if (acl) {
		if (!error)
			error = __ext4_set_acl(handle, inode, ACL_TYPE_ACCESS,
					       acl, XATTR_CREATE);
		posix_acl_release(acl);
	}
	return error;
}
Commit	Line	Data
ac27a0ec	1	/*
617ba13b	2	* linux/fs/ext4/acl.c
ac27a0ec DK	3	*
	4	* Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
	5	*/
	6
b8cb5a54	7	#include <linux/quotaops.h>
3dcf5451 CH	8	#include "ext4_jbd2.h"
3dcf5451 CH	9	#include "ext4.h"
ac27a0ec DK	10	#include "xattr.h"
	11	#include "acl.h"
	12
	13	/*
	14	* Convert from filesystem to in-memory representation.
	15	*/
	16	static struct posix_acl *
617ba13b	17	ext4_acl_from_disk(const void *value, size_t size)
ac27a0ec DK	18	{
	19	const char end = (char )value + size;
	20	int n, count;
	21	struct posix_acl *acl;
	22
	23	if (!value)
	24	return NULL;
617ba13b	25	if (size < sizeof(ext4_acl_header))
ac27a0ec	26	return ERR_PTR(-EINVAL);
617ba13b MC	27	if (((ext4_acl_header *)value)->a_version !=
617ba13b MC	28	cpu_to_le32(EXT4_ACL_VERSION))
ac27a0ec	29	return ERR_PTR(-EINVAL);
617ba13b MC	30	value = (char *)value + sizeof(ext4_acl_header);
617ba13b MC	31	count = ext4_acl_count(size);
ac27a0ec DK	32	if (count < 0)
	33	return ERR_PTR(-EINVAL);
	34	if (count == 0)
	35	return NULL;
216553c4	36	acl = posix_acl_alloc(count, GFP_NOFS);
ac27a0ec DK	37	if (!acl)
ac27a0ec DK	38	return ERR_PTR(-ENOMEM);
2b2d6d01	39	for (n = 0; n < count; n++) {
617ba13b MC	40	ext4_acl_entry *entry =
	41	(ext4_acl_entry *)value;
	42	if ((char *)value + sizeof(ext4_acl_entry_short) > end)
ac27a0ec DK	43	goto fail;
	44	acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
	45	acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
2b2d6d01 TT	46
	47	switch (acl->a_entries[n].e_tag) {
	48	case ACL_USER_OBJ:
	49	case ACL_GROUP_OBJ:
	50	case ACL_MASK:
	51	case ACL_OTHER:
	52	value = (char *)value +
	53	sizeof(ext4_acl_entry_short);
2b2d6d01 TT	54	break;
	55
	56	case ACL_USER:
af84df93 EB	57	value = (char *)value + sizeof(ext4_acl_entry);
	58	if ((char *)value > end)
	59	goto fail;
	60	acl->a_entries[n].e_uid =
	61	make_kuid(&init_user_ns,
	62	le32_to_cpu(entry->e_id));
	63	break;
2b2d6d01 TT	64	case ACL_GROUP:
	65	value = (char *)value + sizeof(ext4_acl_entry);
	66	if ((char *)value > end)
ac27a0ec	67	goto fail;
af84df93 EB	68	acl->a_entries[n].e_gid =
	69	make_kgid(&init_user_ns,
	70	le32_to_cpu(entry->e_id));
2b2d6d01 TT	71	break;
	72
	73	default:
	74	goto fail;
ac27a0ec DK	75	}
	76	}
	77	if (value != end)
	78	goto fail;
	79	return acl;
	80
	81	fail:
	82	posix_acl_release(acl);
	83	return ERR_PTR(-EINVAL);
	84	}
	85
	86	/*
	87	* Convert from in-memory to filesystem representation.
	88	*/
	89	static void *
617ba13b	90	ext4_acl_to_disk(const struct posix_acl acl, size_t size)
ac27a0ec	91	{
617ba13b	92	ext4_acl_header *ext_acl;
ac27a0ec DK	93	char *e;
	94	size_t n;
	95
617ba13b MC	96	*size = ext4_acl_size(acl->a_count);
617ba13b MC	97	ext_acl = kmalloc(sizeof(ext4_acl_header) + acl->a_count *
216553c4	98	sizeof(ext4_acl_entry), GFP_NOFS);
ac27a0ec DK	99	if (!ext_acl)
ac27a0ec DK	100	return ERR_PTR(-ENOMEM);
617ba13b MC	101	ext_acl->a_version = cpu_to_le32(EXT4_ACL_VERSION);
617ba13b MC	102	e = (char *)ext_acl + sizeof(ext4_acl_header);
2b2d6d01	103	for (n = 0; n < acl->a_count; n++) {
af84df93	104	const struct posix_acl_entry *acl_e = &acl->a_entries[n];
617ba13b	105	ext4_acl_entry entry = (ext4_acl_entry )e;
af84df93 EB	106	entry->e_tag = cpu_to_le16(acl_e->e_tag);
	107	entry->e_perm = cpu_to_le16(acl_e->e_perm);
	108	switch (acl_e->e_tag) {
2b2d6d01	109	case ACL_USER:
af84df93 EB	110	entry->e_id = cpu_to_le32(
	111	from_kuid(&init_user_ns, acl_e->e_uid));
	112	e += sizeof(ext4_acl_entry);
	113	break;
2b2d6d01	114	case ACL_GROUP:
af84df93 EB	115	entry->e_id = cpu_to_le32(
af84df93 EB	116	from_kgid(&init_user_ns, acl_e->e_gid));
2b2d6d01 TT	117	e += sizeof(ext4_acl_entry);
	118	break;
	119
	120	case ACL_USER_OBJ:
	121	case ACL_GROUP_OBJ:
	122	case ACL_MASK:
	123	case ACL_OTHER:
	124	e += sizeof(ext4_acl_entry_short);
	125	break;
	126
	127	default:
	128	goto fail;
ac27a0ec DK	129	}
	130	}
	131	return (char *)ext_acl;
	132
	133	fail:
	134	kfree(ext_acl);
	135	return ERR_PTR(-EINVAL);
	136	}
	137
ac27a0ec DK	138	/*
	139	* Inode operation get_posix_acl().
	140	*
	141	* inode->i_mutex: don't care
	142	*/
4e34e719	143	struct posix_acl *
617ba13b	144	ext4_get_acl(struct inode *inode, int type)
ac27a0ec	145	{
ac27a0ec DK	146	int name_index;
	147	char *value = NULL;
	148	struct posix_acl *acl;
	149	int retval;
	150
2b2d6d01 TT	151	switch (type) {
2b2d6d01 TT	152	case ACL_TYPE_ACCESS:
2b2d6d01 TT	153	name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
2b2d6d01 TT	154	break;
2b2d6d01	155	case ACL_TYPE_DEFAULT:
2b2d6d01 TT	156	name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
2b2d6d01 TT	157	break;
2b2d6d01	158	default:
073aaa1b	159	BUG();
ac27a0ec	160	}
617ba13b	161	retval = ext4_xattr_get(inode, name_index, "", NULL, 0);
ac27a0ec	162	if (retval > 0) {
216553c4	163	value = kmalloc(retval, GFP_NOFS);
ac27a0ec DK	164	if (!value)
ac27a0ec DK	165	return ERR_PTR(-ENOMEM);
617ba13b	166	retval = ext4_xattr_get(inode, name_index, "", value, retval);
ac27a0ec DK	167	}
ac27a0ec DK	168	if (retval > 0)
617ba13b	169	acl = ext4_acl_from_disk(value, retval);
ac27a0ec DK	170	else if (retval == -ENODATA \|\| retval == -ENOSYS)
	171	acl = NULL;
	172	else
	173	acl = ERR_PTR(retval);
	174	kfree(value);
	175
ac27a0ec DK	176	return acl;
	177	}
	178
	179	/*
	180	* Set the access or default ACL of an inode.
	181	*
617ba13b	182	* inode->i_mutex: down unless called from ext4_new_inode
ac27a0ec DK	183	*/
ac27a0ec DK	184	static int
64e178a7	185	__ext4_set_acl(handle_t handle, struct inode inode, int type,
af65207c	186	struct posix_acl *acl, int xattr_flags)
ac27a0ec	187	{
ac27a0ec DK	188	int name_index;
	189	void *value = NULL;
	190	size_t size = 0;
	191	int error;
	192
2b2d6d01 TT	193	switch (type) {
	194	case ACL_TYPE_ACCESS:
	195	name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
2b2d6d01	196	break;
ac27a0ec	197
2b2d6d01 TT	198	case ACL_TYPE_DEFAULT:
	199	name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
	200	if (!S_ISDIR(inode->i_mode))
	201	return acl ? -EACCES : 0;
	202	break;
ac27a0ec	203
2b2d6d01 TT	204	default:
2b2d6d01 TT	205	return -EINVAL;
ac27a0ec DK	206	}
ac27a0ec DK	207	if (acl) {
617ba13b	208	value = ext4_acl_to_disk(acl, &size);
ac27a0ec DK	209	if (IS_ERR(value))
	210	return (int)PTR_ERR(value);
	211	}
	212
617ba13b	213	error = ext4_xattr_set_handle(handle, inode, name_index, "",
af65207c	214	value, size, xattr_flags);
ac27a0ec DK	215
ac27a0ec DK	216	kfree(value);
397e4341	217	if (!error) {
073aaa1b	218	set_cached_acl(inode, type, acl);
397e4341	219	}
2b2d6d01	220
ac27a0ec DK	221	return error;
	222	}
	223
ac27a0ec	224	int
64e178a7	225	ext4_set_acl(struct inode inode, struct posix_acl acl, int type)
ac27a0ec	226	{
bc26ab5f	227	handle_t *handle;
c1a5d5f6 TE	228	int error, credits, retries = 0;
c1a5d5f6 TE	229	size_t acl_size = acl ? ext4_acl_size(acl->a_count) : 0;
a3bb2d55 JK	230	umode_t mode = inode->i_mode;
a3bb2d55 JK	231	int update_mode = 0;
bc26ab5f	232
b8cb5a54 TE	233	error = dquot_initialize(inode);
	234	if (error)
	235	return error;
bc26ab5f	236	retry:
af65207c TE	237	error = ext4_xattr_set_credits(inode, acl_size, false /* is_create */,
af65207c TE	238	&credits);
dec214d0 TE	239	if (error)
	240	return error;
	241
c1a5d5f6	242	handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
64e178a7 CH	243	if (IS_ERR(handle))
	244	return PTR_ERR(handle);
	245
a3bb2d55 JK	246	if ((type == ACL_TYPE_ACCESS) && acl) {
	247	error = posix_acl_update_mode(inode, &mode, &acl);
	248	if (error)
	249	goto out_stop;
	250	update_mode = 1;
	251	}
	252
af65207c	253	error = __ext4_set_acl(handle, inode, type, acl, 0 /* xattr_flags */);
a3bb2d55 JK	254	if (!error && update_mode) {
	255	inode->i_mode = mode;
	256	inode->i_ctime = current_time(inode);
	257	ext4_mark_inode_dirty(handle, inode);
	258	}
	259	out_stop:
bc26ab5f	260	ext4_journal_stop(handle);
64e178a7	261	if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
bc26ab5f	262	goto retry;
ac27a0ec DK	263	return error;
	264	}
	265
	266	/*
64e178a7 CH	267	* Initialize the ACLs of a new inode. Called from ext4_new_inode.
	268	*
	269	* dir->i_mutex: down
	270	* inode->i_mutex: up (access to inode is still exclusive)
ac27a0ec	271	*/
64e178a7 CH	272	int
64e178a7 CH	273	ext4_init_acl(handle_t handle, struct inode inode, struct inode *dir)
ac27a0ec	274	{
64e178a7	275	struct posix_acl default_acl, acl;
ac27a0ec DK	276	int error;
ac27a0ec DK	277
64e178a7 CH	278	error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
	279	if (error)
	280	return error;
ac27a0ec	281
64e178a7 CH	282	if (default_acl) {
64e178a7 CH	283	error = __ext4_set_acl(handle, inode, ACL_TYPE_DEFAULT,
af65207c	284	default_acl, XATTR_CREATE);
64e178a7 CH	285	posix_acl_release(default_acl);
	286	}
	287	if (acl) {
	288	if (!error)
	289	error = __ext4_set_acl(handle, inode, ACL_TYPE_ACCESS,
af65207c	290	acl, XATTR_CREATE);
64e178a7	291	posix_acl_release(acl);
24ec19b0	292	}
ac27a0ec DK	293	return error;
ac27a0ec DK	294	}