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

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

#include <linux/init.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/capability.h>
#include <linux/fs.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;

	if (!test_opt(inode->i_sb, POSIX_ACL))
		return NULL;

	acl = get_cached_acl(inode, type);
	if (acl != ACL_NOT_CACHED)
		return acl;

	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);

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

	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 name_index;
	void *value = NULL;
	size_t size = 0;
	int error;

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

	switch (type) {
	case ACL_TYPE_ACCESS:
		name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
		if (acl) {
			error = posix_acl_equiv_mode(acl, &inode->i_mode);
			if (error < 0)
				return error;
			else {
				inode->i_ctime = ext4_current_time(inode);
				ext4_mark_inode_dirty(handle, inode);
				if (error == 0)
					acl = NULL;
			}
		}
		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, 0);

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

	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 *acl = NULL;
	int error = 0;

	if (!S_ISLNK(inode->i_mode)) {
		if (test_opt(dir->i_sb, POSIX_ACL)) {
			acl = ext4_get_acl(dir, ACL_TYPE_DEFAULT);
			if (IS_ERR(acl))
				return PTR_ERR(acl);
		}
		if (!acl)
			inode->i_mode &= ~current_umask();
	}
	if (test_opt(inode->i_sb, POSIX_ACL) && acl) {
		if (S_ISDIR(inode->i_mode)) {
			error = ext4_set_acl(handle, inode,
					     ACL_TYPE_DEFAULT, acl);
			if (error)
				goto cleanup;
		}
		error = __posix_acl_create(&acl, GFP_NOFS, &inode->i_mode);
		if (error < 0)
			return error;

		if (error > 0) {
			/* This is an extended ACL */
			error = ext4_set_acl(handle, inode, ACL_TYPE_ACCESS, acl);
		}
	}
cleanup:
	posix_acl_release(acl);
	return error;
}

/*
 * Does chmod for an inode that may have an Access Control List. The
 * inode->i_mode field must be updated to the desired value by the caller
 * before calling this function.
 * Returns 0 on success, or a negative error number.
 *
 * We change the ACL rather than storing some ACL entries in the file
 * mode permission bits (which would be more efficient), because that
 * would break once additional permissions (like  ACL_APPEND, ACL_DELETE
 * for directories) are added. There are no more bits available in the
 * file mode.
 *
 * inode->i_mutex: down
 */
int
ext4_acl_chmod(struct inode *inode)
{
	struct posix_acl *acl;
	handle_t *handle;
	int retries = 0;
	int error;


	if (S_ISLNK(inode->i_mode))
		return -EOPNOTSUPP;
	if (!test_opt(inode->i_sb, POSIX_ACL))
		return 0;
	acl = ext4_get_acl(inode, ACL_TYPE_ACCESS);
	if (IS_ERR(acl) || !acl)
		return PTR_ERR(acl);
	error = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
	if (error)
		return error;
retry:
	handle = ext4_journal_start(inode, EXT4_HT_XATTR,
				    ext4_jbd2_credits_xattr(inode));
	if (IS_ERR(handle)) {
		error = PTR_ERR(handle);
		ext4_std_error(inode->i_sb, error);
		goto out;
	}
	error = ext4_set_acl(handle, inode, ACL_TYPE_ACCESS, acl);
	ext4_journal_stop(handle);
	if (error == -ENOSPC &&
	    ext4_should_retry_alloc(inode->i_sb, &retries))
		goto retry;
out:
	posix_acl_release(acl);
	return error;
}

/*
 * Extended attribute handlers
 */
static size_t
ext4_xattr_list_acl_access(struct dentry *dentry, char *list, size_t list_len,
			   const char *name, size_t name_len, int type)
{
	const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);

	if (!test_opt(dentry->d_sb, POSIX_ACL))
		return 0;
	if (list && size <= list_len)
		memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
	return size;
}

static size_t
ext4_xattr_list_acl_default(struct dentry *dentry, char *list, size_t list_len,
			    const char *name, size_t name_len, int type)
{
	const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);

	if (!test_opt(dentry->d_sb, POSIX_ACL))
		return 0;
	if (list && size <= list_len)
		memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
	return size;
}

static int
ext4_xattr_get_acl(struct dentry *dentry, const char *name, void *buffer,
		   size_t size, int type)
{
	struct posix_acl *acl;
	int error;

	if (strcmp(name, "") != 0)
		return -EINVAL;
	if (!test_opt(dentry->d_sb, POSIX_ACL))
		return -EOPNOTSUPP;

	acl = ext4_get_acl(dentry->d_inode, type);
	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (acl == NULL)
		return -ENODATA;
	error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
	posix_acl_release(acl);

	return error;
}

static int
ext4_xattr_set_acl(struct dentry *dentry, const char *name, const void *value,
		   size_t size, int flags, int type)
{
	struct inode *inode = dentry->d_inode;
	handle_t *handle;
	struct posix_acl *acl;
	int error, retries = 0;

	if (strcmp(name, "") != 0)
		return -EINVAL;
	if (!test_opt(inode->i_sb, POSIX_ACL))
		return -EOPNOTSUPP;
	if (!inode_owner_or_capable(inode))
		return -EPERM;

	if (value) {
		acl = posix_acl_from_xattr(&init_user_ns, value, size);
		if (IS_ERR(acl))
			return PTR_ERR(acl);
		else if (acl) {
			error = posix_acl_valid(acl);
			if (error)
				goto release_and_out;
		}
	} else
		acl = NULL;

retry:
	handle = ext4_journal_start(inode, EXT4_HT_XATTR,
				    ext4_jbd2_credits_xattr(inode));
	if (IS_ERR(handle)) {
		error = PTR_ERR(handle);
		goto release_and_out;
	}
	error = ext4_set_acl(handle, inode, type, acl);
	ext4_journal_stop(handle);
	if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
		goto retry;

release_and_out:
	posix_acl_release(acl);
	return error;
}

const struct xattr_handler ext4_xattr_acl_access_handler = {
	.prefix	= POSIX_ACL_XATTR_ACCESS,
	.flags	= ACL_TYPE_ACCESS,
	.list	= ext4_xattr_list_acl_access,
	.get	= ext4_xattr_get_acl,
	.set	= ext4_xattr_set_acl,
};

const struct xattr_handler ext4_xattr_acl_default_handler = {
	.prefix	= POSIX_ACL_XATTR_DEFAULT,
	.flags	= ACL_TYPE_DEFAULT,
	.list	= ext4_xattr_list_acl_default,
	.get	= ext4_xattr_get_acl,
	.set	= ext4_xattr_set_acl,
};
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
	7	#include <linux/init.h>
	8	#include <linux/sched.h>
	9	#include <linux/slab.h>
	10	#include <linux/capability.h>
	11	#include <linux/fs.h>
3dcf5451 CH	12	#include "ext4_jbd2.h"
3dcf5451 CH	13	#include "ext4.h"
ac27a0ec DK	14	#include "xattr.h"
	15	#include "acl.h"
	16
	17	/*
	18	* Convert from filesystem to in-memory representation.
	19	*/
	20	static struct posix_acl *
617ba13b	21	ext4_acl_from_disk(const void *value, size_t size)
ac27a0ec DK	22	{
	23	const char end = (char )value + size;
	24	int n, count;
	25	struct posix_acl *acl;
	26
	27	if (!value)
	28	return NULL;
617ba13b	29	if (size < sizeof(ext4_acl_header))
ac27a0ec	30	return ERR_PTR(-EINVAL);
617ba13b MC	31	if (((ext4_acl_header *)value)->a_version !=
617ba13b MC	32	cpu_to_le32(EXT4_ACL_VERSION))
ac27a0ec	33	return ERR_PTR(-EINVAL);
617ba13b MC	34	value = (char *)value + sizeof(ext4_acl_header);
617ba13b MC	35	count = ext4_acl_count(size);
ac27a0ec DK	36	if (count < 0)
	37	return ERR_PTR(-EINVAL);
	38	if (count == 0)
	39	return NULL;
216553c4	40	acl = posix_acl_alloc(count, GFP_NOFS);
ac27a0ec DK	41	if (!acl)
ac27a0ec DK	42	return ERR_PTR(-ENOMEM);
2b2d6d01	43	for (n = 0; n < count; n++) {
617ba13b MC	44	ext4_acl_entry *entry =
	45	(ext4_acl_entry *)value;
	46	if ((char *)value + sizeof(ext4_acl_entry_short) > end)
ac27a0ec DK	47	goto fail;
	48	acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
	49	acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
2b2d6d01 TT	50
	51	switch (acl->a_entries[n].e_tag) {
	52	case ACL_USER_OBJ:
	53	case ACL_GROUP_OBJ:
	54	case ACL_MASK:
	55	case ACL_OTHER:
	56	value = (char *)value +
	57	sizeof(ext4_acl_entry_short);
2b2d6d01 TT	58	break;
	59
	60	case ACL_USER:
af84df93 EB	61	value = (char *)value + sizeof(ext4_acl_entry);
	62	if ((char *)value > end)
	63	goto fail;
	64	acl->a_entries[n].e_uid =
	65	make_kuid(&init_user_ns,
	66	le32_to_cpu(entry->e_id));
	67	break;
2b2d6d01 TT	68	case ACL_GROUP:
	69	value = (char *)value + sizeof(ext4_acl_entry);
	70	if ((char *)value > end)
ac27a0ec	71	goto fail;
af84df93 EB	72	acl->a_entries[n].e_gid =
	73	make_kgid(&init_user_ns,
	74	le32_to_cpu(entry->e_id));
2b2d6d01 TT	75	break;
	76
	77	default:
	78	goto fail;
ac27a0ec DK	79	}
	80	}
	81	if (value != end)
	82	goto fail;
	83	return acl;
	84
	85	fail:
	86	posix_acl_release(acl);
	87	return ERR_PTR(-EINVAL);
	88	}
	89
	90	/*
	91	* Convert from in-memory to filesystem representation.
	92	*/
	93	static void *
617ba13b	94	ext4_acl_to_disk(const struct posix_acl acl, size_t size)
ac27a0ec	95	{
617ba13b	96	ext4_acl_header *ext_acl;
ac27a0ec DK	97	char *e;
	98	size_t n;
	99
617ba13b MC	100	*size = ext4_acl_size(acl->a_count);
617ba13b MC	101	ext_acl = kmalloc(sizeof(ext4_acl_header) + acl->a_count *
216553c4	102	sizeof(ext4_acl_entry), GFP_NOFS);
ac27a0ec DK	103	if (!ext_acl)
ac27a0ec DK	104	return ERR_PTR(-ENOMEM);
617ba13b MC	105	ext_acl->a_version = cpu_to_le32(EXT4_ACL_VERSION);
617ba13b MC	106	e = (char *)ext_acl + sizeof(ext4_acl_header);
2b2d6d01	107	for (n = 0; n < acl->a_count; n++) {
af84df93	108	const struct posix_acl_entry *acl_e = &acl->a_entries[n];
617ba13b	109	ext4_acl_entry entry = (ext4_acl_entry )e;
af84df93 EB	110	entry->e_tag = cpu_to_le16(acl_e->e_tag);
	111	entry->e_perm = cpu_to_le16(acl_e->e_perm);
	112	switch (acl_e->e_tag) {
2b2d6d01	113	case ACL_USER:
af84df93 EB	114	entry->e_id = cpu_to_le32(
	115	from_kuid(&init_user_ns, acl_e->e_uid));
	116	e += sizeof(ext4_acl_entry);
	117	break;
2b2d6d01	118	case ACL_GROUP:
af84df93 EB	119	entry->e_id = cpu_to_le32(
af84df93 EB	120	from_kgid(&init_user_ns, acl_e->e_gid));
2b2d6d01 TT	121	e += sizeof(ext4_acl_entry);
	122	break;
	123
	124	case ACL_USER_OBJ:
	125	case ACL_GROUP_OBJ:
	126	case ACL_MASK:
	127	case ACL_OTHER:
	128	e += sizeof(ext4_acl_entry_short);
	129	break;
	130
	131	default:
	132	goto fail;
ac27a0ec DK	133	}
	134	}
	135	return (char *)ext_acl;
	136
	137	fail:
	138	kfree(ext_acl);
	139	return ERR_PTR(-EINVAL);
	140	}
	141
ac27a0ec DK	142	/*
	143	* Inode operation get_posix_acl().
	144	*
	145	* inode->i_mutex: don't care
	146	*/
4e34e719	147	struct posix_acl *
617ba13b	148	ext4_get_acl(struct inode *inode, int type)
ac27a0ec	149	{
ac27a0ec DK	150	int name_index;
	151	char *value = NULL;
	152	struct posix_acl *acl;
	153	int retval;
	154
	155	if (!test_opt(inode->i_sb, POSIX_ACL))
	156	return NULL;
	157
073aaa1b AV	158	acl = get_cached_acl(inode, type);
	159	if (acl != ACL_NOT_CACHED)
	160	return acl;
	161
2b2d6d01 TT	162	switch (type) {
2b2d6d01 TT	163	case ACL_TYPE_ACCESS:
2b2d6d01 TT	164	name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
2b2d6d01 TT	165	break;
2b2d6d01	166	case ACL_TYPE_DEFAULT:
2b2d6d01 TT	167	name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
2b2d6d01 TT	168	break;
2b2d6d01	169	default:
073aaa1b	170	BUG();
ac27a0ec	171	}
617ba13b	172	retval = ext4_xattr_get(inode, name_index, "", NULL, 0);
ac27a0ec	173	if (retval > 0) {
216553c4	174	value = kmalloc(retval, GFP_NOFS);
ac27a0ec DK	175	if (!value)
ac27a0ec DK	176	return ERR_PTR(-ENOMEM);
617ba13b	177	retval = ext4_xattr_get(inode, name_index, "", value, retval);
ac27a0ec DK	178	}
ac27a0ec DK	179	if (retval > 0)
617ba13b	180	acl = ext4_acl_from_disk(value, retval);
ac27a0ec DK	181	else if (retval == -ENODATA \|\| retval == -ENOSYS)
	182	acl = NULL;
	183	else
	184	acl = ERR_PTR(retval);
	185	kfree(value);
	186
073aaa1b AV	187	if (!IS_ERR(acl))
073aaa1b AV	188	set_cached_acl(inode, type, acl);
2b2d6d01	189
ac27a0ec DK	190	return acl;
	191	}
	192
	193	/*
	194	* Set the access or default ACL of an inode.
	195	*
617ba13b	196	* inode->i_mutex: down unless called from ext4_new_inode
ac27a0ec DK	197	*/
ac27a0ec DK	198	static int
617ba13b	199	ext4_set_acl(handle_t handle, struct inode inode, int type,
ac27a0ec DK	200	struct posix_acl *acl)
ac27a0ec DK	201	{
ac27a0ec DK	202	int name_index;
	203	void *value = NULL;
	204	size_t size = 0;
	205	int error;
	206
	207	if (S_ISLNK(inode->i_mode))
	208	return -EOPNOTSUPP;
	209
2b2d6d01 TT	210	switch (type) {
	211	case ACL_TYPE_ACCESS:
	212	name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
	213	if (acl) {
d6952123	214	error = posix_acl_equiv_mode(acl, &inode->i_mode);
2b2d6d01 TT	215	if (error < 0)
	216	return error;
	217	else {
c6ac12a6	218	inode->i_ctime = ext4_current_time(inode);
2b2d6d01 TT	219	ext4_mark_inode_dirty(handle, inode);
	220	if (error == 0)
	221	acl = NULL;
ac27a0ec	222	}
2b2d6d01 TT	223	}
2b2d6d01 TT	224	break;
ac27a0ec	225
2b2d6d01 TT	226	case ACL_TYPE_DEFAULT:
	227	name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
	228	if (!S_ISDIR(inode->i_mode))
	229	return acl ? -EACCES : 0;
	230	break;
ac27a0ec	231
2b2d6d01 TT	232	default:
2b2d6d01 TT	233	return -EINVAL;
ac27a0ec DK	234	}
ac27a0ec DK	235	if (acl) {
617ba13b	236	value = ext4_acl_to_disk(acl, &size);
ac27a0ec DK	237	if (IS_ERR(value))
	238	return (int)PTR_ERR(value);
	239	}
	240
617ba13b	241	error = ext4_xattr_set_handle(handle, inode, name_index, "",
ac27a0ec DK	242	value, size, 0);
	243
	244	kfree(value);
073aaa1b AV	245	if (!error)
073aaa1b AV	246	set_cached_acl(inode, type, acl);
2b2d6d01	247
ac27a0ec DK	248	return error;
	249	}
	250
ac27a0ec	251	/*
617ba13b	252	* Initialize the ACLs of a new inode. Called from ext4_new_inode.
ac27a0ec DK	253	*
	254	* dir->i_mutex: down
	255	* inode->i_mutex: up (access to inode is still exclusive)
	256	*/
	257	int
617ba13b	258	ext4_init_acl(handle_t handle, struct inode inode, struct inode *dir)
ac27a0ec DK	259	{
	260	struct posix_acl *acl = NULL;
	261	int error = 0;
	262
	263	if (!S_ISLNK(inode->i_mode)) {
	264	if (test_opt(dir->i_sb, POSIX_ACL)) {
617ba13b	265	acl = ext4_get_acl(dir, ACL_TYPE_DEFAULT);
ac27a0ec DK	266	if (IS_ERR(acl))
	267	return PTR_ERR(acl);
	268	}
	269	if (!acl)
ce3b0f8d	270	inode->i_mode &= ~current_umask();
ac27a0ec DK	271	}
ac27a0ec DK	272	if (test_opt(inode->i_sb, POSIX_ACL) && acl) {
ac27a0ec	273	if (S_ISDIR(inode->i_mode)) {
617ba13b	274	error = ext4_set_acl(handle, inode,
ac27a0ec DK	275	ACL_TYPE_DEFAULT, acl);
	276	if (error)
	277	goto cleanup;
	278	}
37bc1539	279	error = __posix_acl_create(&acl, GFP_NOFS, &inode->i_mode);
826cae2f AV	280	if (error < 0)
	281	return error;
	282
826cae2f AV	283	if (error > 0) {
	284	/* This is an extended ACL */
	285	error = ext4_set_acl(handle, inode, ACL_TYPE_ACCESS, acl);
ac27a0ec	286	}
ac27a0ec DK	287	}
	288	cleanup:
	289	posix_acl_release(acl);
	290	return error;
	291	}
	292
	293	/*
	294	* Does chmod for an inode that may have an Access Control List. The
	295	* inode->i_mode field must be updated to the desired value by the caller
	296	* before calling this function.
	297	* Returns 0 on success, or a negative error number.
	298	*
	299	* We change the ACL rather than storing some ACL entries in the file
	300	* mode permission bits (which would be more efficient), because that
	301	* would break once additional permissions (like ACL_APPEND, ACL_DELETE
	302	* for directories) are added. There are no more bits available in the
	303	* file mode.
	304	*
	305	* inode->i_mutex: down
	306	*/
	307	int
617ba13b	308	ext4_acl_chmod(struct inode *inode)
ac27a0ec	309	{
bc26ab5f AV	310	struct posix_acl *acl;
	311	handle_t *handle;
	312	int retries = 0;
63f57933	313	int error;
ac27a0ec	314
bc26ab5f	315
ac27a0ec DK	316	if (S_ISLNK(inode->i_mode))
	317	return -EOPNOTSUPP;
	318	if (!test_opt(inode->i_sb, POSIX_ACL))
	319	return 0;
617ba13b	320	acl = ext4_get_acl(inode, ACL_TYPE_ACCESS);
ac27a0ec DK	321	if (IS_ERR(acl) \|\| !acl)
ac27a0ec DK	322	return PTR_ERR(acl);
5bf3258f	323	error = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
bc26ab5f AV	324	if (error)
	325	return error;
	326	retry:
9924a92a	327	handle = ext4_journal_start(inode, EXT4_HT_XATTR,
95eaefbd	328	ext4_jbd2_credits_xattr(inode));
bc26ab5f AV	329	if (IS_ERR(handle)) {
	330	error = PTR_ERR(handle);
	331	ext4_std_error(inode->i_sb, error);
	332	goto out;
ac27a0ec	333	}
bc26ab5f AV	334	error = ext4_set_acl(handle, inode, ACL_TYPE_ACCESS, acl);
	335	ext4_journal_stop(handle);
	336	if (error == -ENOSPC &&
	337	ext4_should_retry_alloc(inode->i_sb, &retries))
	338	goto retry;
ac27a0ec	339	out:
bc26ab5f	340	posix_acl_release(acl);
ac27a0ec DK	341	return error;
	342	}
	343
	344	/*
	345	* Extended attribute handlers
	346	*/
	347	static size_t
431547b3 CH	348	ext4_xattr_list_acl_access(struct dentry dentry, char list, size_t list_len,
431547b3 CH	349	const char *name, size_t name_len, int type)
ac27a0ec DK	350	{
	351	const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
	352
431547b3	353	if (!test_opt(dentry->d_sb, POSIX_ACL))
ac27a0ec DK	354	return 0;
	355	if (list && size <= list_len)
	356	memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
	357	return size;
	358	}
	359
	360	static size_t
431547b3 CH	361	ext4_xattr_list_acl_default(struct dentry dentry, char list, size_t list_len,
431547b3 CH	362	const char *name, size_t name_len, int type)
ac27a0ec DK	363	{
	364	const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
	365
431547b3	366	if (!test_opt(dentry->d_sb, POSIX_ACL))
ac27a0ec DK	367	return 0;
	368	if (list && size <= list_len)
	369	memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
	370	return size;
	371	}
	372
	373	static int
431547b3 CH	374	ext4_xattr_get_acl(struct dentry dentry, const char name, void *buffer,
431547b3 CH	375	size_t size, int type)
ac27a0ec DK	376	{
	377	struct posix_acl *acl;
	378	int error;
	379
431547b3 CH	380	if (strcmp(name, "") != 0)
	381	return -EINVAL;
	382	if (!test_opt(dentry->d_sb, POSIX_ACL))
ac27a0ec DK	383	return -EOPNOTSUPP;
ac27a0ec DK	384
431547b3	385	acl = ext4_get_acl(dentry->d_inode, type);
ac27a0ec DK	386	if (IS_ERR(acl))
	387	return PTR_ERR(acl);
	388	if (acl == NULL)
	389	return -ENODATA;
5f3a4a28	390	error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
ac27a0ec DK	391	posix_acl_release(acl);
	392
	393	return error;
	394	}
	395
	396	static int
431547b3 CH	397	ext4_xattr_set_acl(struct dentry dentry, const char name, const void *value,
431547b3 CH	398	size_t size, int flags, int type)
ac27a0ec	399	{
431547b3	400	struct inode *inode = dentry->d_inode;
ac27a0ec DK	401	handle_t *handle;
	402	struct posix_acl *acl;
	403	int error, retries = 0;
	404
431547b3 CH	405	if (strcmp(name, "") != 0)
431547b3 CH	406	return -EINVAL;
ac27a0ec DK	407	if (!test_opt(inode->i_sb, POSIX_ACL))
ac27a0ec DK	408	return -EOPNOTSUPP;
2e149670	409	if (!inode_owner_or_capable(inode))
ac27a0ec DK	410	return -EPERM;
	411
	412	if (value) {
5f3a4a28	413	acl = posix_acl_from_xattr(&init_user_ns, value, size);
ac27a0ec DK	414	if (IS_ERR(acl))
	415	return PTR_ERR(acl);
	416	else if (acl) {
	417	error = posix_acl_valid(acl);
	418	if (error)
	419	goto release_and_out;
	420	}
	421	} else
	422	acl = NULL;
	423
	424	retry:
9924a92a	425	handle = ext4_journal_start(inode, EXT4_HT_XATTR,
95eaefbd	426	ext4_jbd2_credits_xattr(inode));
24ec19b0 ES	427	if (IS_ERR(handle)) {
	428	error = PTR_ERR(handle);
	429	goto release_and_out;
	430	}
617ba13b MC	431	error = ext4_set_acl(handle, inode, type, acl);
	432	ext4_journal_stop(handle);
	433	if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
ac27a0ec DK	434	goto retry;
	435
	436	release_and_out:
	437	posix_acl_release(acl);
	438	return error;
	439	}
	440
11e27528	441	const struct xattr_handler ext4_xattr_acl_access_handler = {
ac27a0ec	442	.prefix = POSIX_ACL_XATTR_ACCESS,
431547b3	443	.flags = ACL_TYPE_ACCESS,
617ba13b	444	.list = ext4_xattr_list_acl_access,
431547b3 CH	445	.get = ext4_xattr_get_acl,
431547b3 CH	446	.set = ext4_xattr_set_acl,
ac27a0ec DK	447	};
ac27a0ec DK	448
11e27528	449	const struct xattr_handler ext4_xattr_acl_default_handler = {
ac27a0ec	450	.prefix = POSIX_ACL_XATTR_DEFAULT,
431547b3	451	.flags = ACL_TYPE_DEFAULT,
617ba13b	452	.list = ext4_xattr_list_acl_default,
431547b3 CH	453	.get = ext4_xattr_get_acl,
431547b3 CH	454	.set = ext4_xattr_set_acl,
ac27a0ec	455	};