[net-next-2.6.git] / fs / ext3 / acl.c

/*
 * linux/fs/ext3/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 <linux/ext3_jbd.h>
#include <linux/ext3_fs.h>
#include "xattr.h"
#include "acl.h"

/*
 * Convert from filesystem to in-memory representation.
 */
static struct posix_acl *
ext3_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(ext3_acl_header))
		 return ERR_PTR(-EINVAL);
	if (((ext3_acl_header *)value)->a_version !=
	    cpu_to_le32(EXT3_ACL_VERSION))
		return ERR_PTR(-EINVAL);
	value = (char *)value + sizeof(ext3_acl_header);
	count = ext3_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++) {
		ext3_acl_entry *entry =
			(ext3_acl_entry *)value;
		if ((char *)value + sizeof(ext3_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(ext3_acl_entry_short);
				acl->a_entries[n].e_id = ACL_UNDEFINED_ID;
				break;

			case ACL_USER:
			case ACL_GROUP:
				value = (char *)value + sizeof(ext3_acl_entry);
				if ((char *)value > end)
					goto fail;
				acl->a_entries[n].e_id =
					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 *
ext3_acl_to_disk(const struct posix_acl *acl, size_t *size)
{
	ext3_acl_header *ext_acl;
	char *e;
	size_t n;

	*size = ext3_acl_size(acl->a_count);
	ext_acl = kmalloc(sizeof(ext3_acl_header) + acl->a_count *
			sizeof(ext3_acl_entry), GFP_NOFS);
	if (!ext_acl)
		return ERR_PTR(-ENOMEM);
	ext_acl->a_version = cpu_to_le32(EXT3_ACL_VERSION);
	e = (char *)ext_acl + sizeof(ext3_acl_header);
	for (n=0; n < acl->a_count; n++) {
		ext3_acl_entry *entry = (ext3_acl_entry *)e;
		entry->e_tag  = cpu_to_le16(acl->a_entries[n].e_tag);
		entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
		switch(acl->a_entries[n].e_tag) {
			case ACL_USER:
			case ACL_GROUP:
				entry->e_id =
					cpu_to_le32(acl->a_entries[n].e_id);
				e += sizeof(ext3_acl_entry);
				break;

			case ACL_USER_OBJ:
			case ACL_GROUP_OBJ:
			case ACL_MASK:
			case ACL_OTHER:
				e += sizeof(ext3_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
 */
static struct posix_acl *
ext3_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 = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS;
		break;
	case ACL_TYPE_DEFAULT:
		name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
		break;
	default:
		BUG();
	}

	retval = ext3_xattr_get(inode, name_index, "", NULL, 0);
	if (retval > 0) {
		value = kmalloc(retval, GFP_NOFS);
		if (!value)
			return ERR_PTR(-ENOMEM);
		retval = ext3_xattr_get(inode, name_index, "", value, retval);
	}
	if (retval > 0)
		acl = ext3_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 ext3_new_inode
 */
static int
ext3_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 = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS;
			if (acl) {
				mode_t mode = inode->i_mode;
				error = posix_acl_equiv_mode(acl, &mode);
				if (error < 0)
					return error;
				else {
					inode->i_mode = mode;
					inode->i_ctime = CURRENT_TIME_SEC;
					ext3_mark_inode_dirty(handle, inode);
					if (error == 0)
						acl = NULL;
				}
			}
			break;

		case ACL_TYPE_DEFAULT:
			name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
			if (!S_ISDIR(inode->i_mode))
				return acl ? -EACCES : 0;
			break;

		default:
			return -EINVAL;
	}
	if (acl) {
		value = ext3_acl_to_disk(acl, &size);
		if (IS_ERR(value))
			return (int)PTR_ERR(value);
	}

	error = ext3_xattr_set_handle(handle, inode, name_index, "",
				      value, size, 0);

	kfree(value);

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

	return error;
}

int
ext3_check_acl(struct inode *inode, int mask)
{
	struct posix_acl *acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);

	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (acl) {
		int error = posix_acl_permission(inode, acl, mask);
		posix_acl_release(acl);
		return error;
	}

	return -EAGAIN;
}

/*
 * Initialize the ACLs of a new inode. Called from ext3_new_inode.
 *
 * dir->i_mutex: down
 * inode->i_mutex: up (access to inode is still exclusive)
 */
int
ext3_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 = ext3_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) {
		struct posix_acl *clone;
		mode_t mode;

		if (S_ISDIR(inode->i_mode)) {
			error = ext3_set_acl(handle, inode,
					     ACL_TYPE_DEFAULT, acl);
			if (error)
				goto cleanup;
		}
		clone = posix_acl_clone(acl, GFP_NOFS);
		error = -ENOMEM;
		if (!clone)
			goto cleanup;

		mode = inode->i_mode;
		error = posix_acl_create_masq(clone, &mode);
		if (error >= 0) {
			inode->i_mode = mode;
			if (error > 0) {
				/* This is an extended ACL */
				error = ext3_set_acl(handle, inode,
						     ACL_TYPE_ACCESS, clone);
			}
		}
		posix_acl_release(clone);
	}
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
ext3_acl_chmod(struct inode *inode)
{
	struct posix_acl *acl, *clone;
        int error;

	if (S_ISLNK(inode->i_mode))
		return -EOPNOTSUPP;
	if (!test_opt(inode->i_sb, POSIX_ACL))
		return 0;
	acl = ext3_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;
	error = posix_acl_chmod_masq(clone, inode->i_mode);
	if (!error) {
		handle_t *handle;
		int retries = 0;

	retry:
		handle = ext3_journal_start(inode,
				EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
		if (IS_ERR(handle)) {
			error = PTR_ERR(handle);
			ext3_std_error(inode->i_sb, error);
			goto out;
		}
		error = ext3_set_acl(handle, inode, ACL_TYPE_ACCESS, clone);
		ext3_journal_stop(handle);
		if (error == -ENOSPC &&
		    ext3_should_retry_alloc(inode->i_sb, &retries))
			goto retry;
	}
out:
	posix_acl_release(clone);
	return error;
}

/*
 * Extended attribute handlers
 */
static size_t
ext3_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
ext3_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
ext3_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 = ext3_get_acl(dentry->d_inode, type);
	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (acl == NULL)
		return -ENODATA;
	error = posix_acl_to_xattr(acl, buffer, size);
	posix_acl_release(acl);

	return error;
}

static int
ext3_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 (!is_owner_or_cap(inode))
		return -EPERM;

	if (value) {
		acl = posix_acl_from_xattr(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 = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
	if (IS_ERR(handle))
		return PTR_ERR(handle);
	error = ext3_set_acl(handle, inode, type, acl);
	ext3_journal_stop(handle);
	if (error == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
		goto retry;

release_and_out:
	posix_acl_release(acl);
	return error;
}

const struct xattr_handler ext3_xattr_acl_access_handler = {
	.prefix	= POSIX_ACL_XATTR_ACCESS,
	.flags	= ACL_TYPE_ACCESS,
	.list	= ext3_xattr_list_acl_access,
	.get	= ext3_xattr_get_acl,
	.set	= ext3_xattr_set_acl,
};

const struct xattr_handler ext3_xattr_acl_default_handler = {
	.prefix	= POSIX_ACL_XATTR_DEFAULT,
	.flags	= ACL_TYPE_DEFAULT,
	.list	= ext3_xattr_list_acl_default,
	.get	= ext3_xattr_get_acl,
	.set	= ext3_xattr_set_acl,
};
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/ext3/acl.c
	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>
16f7e0fe	10	#include <linux/capability.h>
1da177e4 LT	11	#include <linux/fs.h>
	12	#include <linux/ext3_jbd.h>
	13	#include <linux/ext3_fs.h>
	14	#include "xattr.h"
	15	#include "acl.h"
	16
	17	/*
	18	* Convert from filesystem to in-memory representation.
	19	*/
	20	static struct posix_acl *
	21	ext3_acl_from_disk(const void *value, size_t size)
	22	{
	23	const char end = (char )value + size;
	24	int n, count;
	25	struct posix_acl *acl;
	26
	27	if (!value)
	28	return NULL;
	29	if (size < sizeof(ext3_acl_header))
	30	return ERR_PTR(-EINVAL);
	31	if (((ext3_acl_header *)value)->a_version !=
	32	cpu_to_le32(EXT3_ACL_VERSION))
	33	return ERR_PTR(-EINVAL);
	34	value = (char *)value + sizeof(ext3_acl_header);
	35	count = ext3_acl_count(size);
	36	if (count < 0)
	37	return ERR_PTR(-EINVAL);
	38	if (count == 0)
	39	return NULL;
c587f0c0	40	acl = posix_acl_alloc(count, GFP_NOFS);
1da177e4 LT	41	if (!acl)
	42	return ERR_PTR(-ENOMEM);
	43	for (n=0; n < count; n++) {
	44	ext3_acl_entry *entry =
	45	(ext3_acl_entry *)value;
	46	if ((char *)value + sizeof(ext3_acl_entry_short) > end)
	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);
	50	switch(acl->a_entries[n].e_tag) {
	51	case ACL_USER_OBJ:
	52	case ACL_GROUP_OBJ:
	53	case ACL_MASK:
	54	case ACL_OTHER:
	55	value = (char *)value +
	56	sizeof(ext3_acl_entry_short);
	57	acl->a_entries[n].e_id = ACL_UNDEFINED_ID;
	58	break;
	59
	60	case ACL_USER:
	61	case ACL_GROUP:
	62	value = (char *)value + sizeof(ext3_acl_entry);
	63	if ((char *)value > end)
	64	goto fail;
	65	acl->a_entries[n].e_id =
	66	le32_to_cpu(entry->e_id);
	67	break;
	68
	69	default:
	70	goto fail;
	71	}
	72	}
	73	if (value != end)
	74	goto fail;
	75	return acl;
	76
	77	fail:
	78	posix_acl_release(acl);
	79	return ERR_PTR(-EINVAL);
	80	}
	81
	82	/*
	83	* Convert from in-memory to filesystem representation.
	84	*/
	85	static void *
	86	ext3_acl_to_disk(const struct posix_acl acl, size_t size)
	87	{
	88	ext3_acl_header *ext_acl;
	89	char *e;
	90	size_t n;
	91
	92	*size = ext3_acl_size(acl->a_count);
f52720ca	93	ext_acl = kmalloc(sizeof(ext3_acl_header) + acl->a_count *
c587f0c0	94	sizeof(ext3_acl_entry), GFP_NOFS);
1da177e4 LT	95	if (!ext_acl)
	96	return ERR_PTR(-ENOMEM);
	97	ext_acl->a_version = cpu_to_le32(EXT3_ACL_VERSION);
	98	e = (char *)ext_acl + sizeof(ext3_acl_header);
	99	for (n=0; n < acl->a_count; n++) {
	100	ext3_acl_entry entry = (ext3_acl_entry )e;
	101	entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
	102	entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
	103	switch(acl->a_entries[n].e_tag) {
	104	case ACL_USER:
	105	case ACL_GROUP:
	106	entry->e_id =
	107	cpu_to_le32(acl->a_entries[n].e_id);
	108	e += sizeof(ext3_acl_entry);
	109	break;
	110
	111	case ACL_USER_OBJ:
	112	case ACL_GROUP_OBJ:
	113	case ACL_MASK:
	114	case ACL_OTHER:
	115	e += sizeof(ext3_acl_entry_short);
	116	break;
	117
	118	default:
	119	goto fail;
	120	}
	121	}
	122	return (char *)ext_acl;
	123
	124	fail:
	125	kfree(ext_acl);
	126	return ERR_PTR(-EINVAL);
	127	}
	128
1da177e4 LT	129	/*
	130	* Inode operation get_posix_acl().
	131	*
1b1dcc1b	132	* inode->i_mutex: don't care
1da177e4 LT	133	*/
	134	static struct posix_acl *
	135	ext3_get_acl(struct inode *inode, int type)
	136	{
1da177e4 LT	137	int name_index;
	138	char *value = NULL;
	139	struct posix_acl *acl;
	140	int retval;
	141
	142	if (!test_opt(inode->i_sb, POSIX_ACL))
	143	return NULL;
	144
073aaa1b AV	145	acl = get_cached_acl(inode, type);
	146	if (acl != ACL_NOT_CACHED)
	147	return acl;
	148
	149	switch (type) {
	150	case ACL_TYPE_ACCESS:
	151	name_index = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS;
	152	break;
	153	case ACL_TYPE_DEFAULT:
	154	name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
	155	break;
	156	default:
	157	BUG();
1da177e4	158	}
073aaa1b	159
1da177e4 LT	160	retval = ext3_xattr_get(inode, name_index, "", NULL, 0);
1da177e4 LT	161	if (retval > 0) {
c587f0c0	162	value = kmalloc(retval, GFP_NOFS);
1da177e4 LT	163	if (!value)
	164	return ERR_PTR(-ENOMEM);
	165	retval = ext3_xattr_get(inode, name_index, "", value, retval);
	166	}
	167	if (retval > 0)
	168	acl = ext3_acl_from_disk(value, retval);
	169	else if (retval == -ENODATA \|\| retval == -ENOSYS)
	170	acl = NULL;
	171	else
	172	acl = ERR_PTR(retval);
	173	kfree(value);
	174
073aaa1b AV	175	if (!IS_ERR(acl))
073aaa1b AV	176	set_cached_acl(inode, type, acl);
1da177e4	177
1da177e4 LT	178	return acl;
	179	}
	180
	181	/*
	182	* Set the access or default ACL of an inode.
	183	*
1b1dcc1b	184	* inode->i_mutex: down unless called from ext3_new_inode
1da177e4 LT	185	*/
	186	static int
	187	ext3_set_acl(handle_t handle, struct inode inode, int type,
	188	struct posix_acl *acl)
	189	{
1da177e4 LT	190	int name_index;
1da177e4 LT	191	void *value = NULL;
dfa08592	192	size_t size = 0;
1da177e4 LT	193	int error;
	194
	195	if (S_ISLNK(inode->i_mode))
	196	return -EOPNOTSUPP;
	197
	198	switch(type) {
	199	case ACL_TYPE_ACCESS:
	200	name_index = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS;
	201	if (acl) {
	202	mode_t mode = inode->i_mode;
	203	error = posix_acl_equiv_mode(acl, &mode);
	204	if (error < 0)
	205	return error;
	206	else {
	207	inode->i_mode = mode;
30e2bab2	208	inode->i_ctime = CURRENT_TIME_SEC;
1da177e4 LT	209	ext3_mark_inode_dirty(handle, inode);
	210	if (error == 0)
	211	acl = NULL;
	212	}
	213	}
	214	break;
	215
	216	case ACL_TYPE_DEFAULT:
	217	name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
	218	if (!S_ISDIR(inode->i_mode))
	219	return acl ? -EACCES : 0;
	220	break;
	221
	222	default:
	223	return -EINVAL;
	224	}
e9ad5620	225	if (acl) {
1da177e4 LT	226	value = ext3_acl_to_disk(acl, &size);
	227	if (IS_ERR(value))
	228	return (int)PTR_ERR(value);
	229	}
	230
	231	error = ext3_xattr_set_handle(handle, inode, name_index, "",
	232	value, size, 0);
	233
	234	kfree(value);
1da177e4	235
073aaa1b AV	236	if (!error)
	237	set_cached_acl(inode, type, acl);
	238
1da177e4 LT	239	return error;
	240	}
	241
1d5ccd1c	242	int
1da177e4 LT	243	ext3_check_acl(struct inode *inode, int mask)
	244	{
	245	struct posix_acl *acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
	246
e493073d AM	247	if (IS_ERR(acl))
e493073d AM	248	return PTR_ERR(acl);
1da177e4 LT	249	if (acl) {
	250	int error = posix_acl_permission(inode, acl, mask);
	251	posix_acl_release(acl);
	252	return error;
	253	}
	254
	255	return -EAGAIN;
	256	}
	257
1da177e4 LT	258	/*
	259	* Initialize the ACLs of a new inode. Called from ext3_new_inode.
	260	*
1b1dcc1b JS	261	* dir->i_mutex: down
1b1dcc1b JS	262	* inode->i_mutex: up (access to inode is still exclusive)
1da177e4 LT	263	*/
	264	int
	265	ext3_init_acl(handle_t handle, struct inode inode, struct inode *dir)
	266	{
	267	struct posix_acl *acl = NULL;
	268	int error = 0;
	269
	270	if (!S_ISLNK(inode->i_mode)) {
	271	if (test_opt(dir->i_sb, POSIX_ACL)) {
	272	acl = ext3_get_acl(dir, ACL_TYPE_DEFAULT);
	273	if (IS_ERR(acl))
	274	return PTR_ERR(acl);
	275	}
	276	if (!acl)
ce3b0f8d	277	inode->i_mode &= ~current_umask();
1da177e4 LT	278	}
	279	if (test_opt(inode->i_sb, POSIX_ACL) && acl) {
	280	struct posix_acl *clone;
	281	mode_t mode;
	282
	283	if (S_ISDIR(inode->i_mode)) {
	284	error = ext3_set_acl(handle, inode,
	285	ACL_TYPE_DEFAULT, acl);
	286	if (error)
	287	goto cleanup;
	288	}
c587f0c0	289	clone = posix_acl_clone(acl, GFP_NOFS);
1da177e4 LT	290	error = -ENOMEM;
	291	if (!clone)
	292	goto cleanup;
	293
	294	mode = inode->i_mode;
	295	error = posix_acl_create_masq(clone, &mode);
	296	if (error >= 0) {
	297	inode->i_mode = mode;
	298	if (error > 0) {
	299	/* This is an extended ACL */
	300	error = ext3_set_acl(handle, inode,
	301	ACL_TYPE_ACCESS, clone);
	302	}
	303	}
	304	posix_acl_release(clone);
	305	}
	306	cleanup:
	307	posix_acl_release(acl);
	308	return error;
	309	}
	310
	311	/*
	312	* Does chmod for an inode that may have an Access Control List. The
	313	* inode->i_mode field must be updated to the desired value by the caller
	314	* before calling this function.
	315	* Returns 0 on success, or a negative error number.
	316	*
	317	* We change the ACL rather than storing some ACL entries in the file
	318	* mode permission bits (which would be more efficient), because that
	319	* would break once additional permissions (like ACL_APPEND, ACL_DELETE
	320	* for directories) are added. There are no more bits available in the
	321	* file mode.
	322	*
1b1dcc1b	323	* inode->i_mutex: down
1da177e4 LT	324	*/
	325	int
	326	ext3_acl_chmod(struct inode *inode)
	327	{
	328	struct posix_acl acl, clone;
	329	int error;
	330
	331	if (S_ISLNK(inode->i_mode))
	332	return -EOPNOTSUPP;
	333	if (!test_opt(inode->i_sb, POSIX_ACL))
	334	return 0;
	335	acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
	336	if (IS_ERR(acl) \|\| !acl)
	337	return PTR_ERR(acl);
	338	clone = posix_acl_clone(acl, GFP_KERNEL);
	339	posix_acl_release(acl);
	340	if (!clone)
	341	return -ENOMEM;
	342	error = posix_acl_chmod_masq(clone, inode->i_mode);
	343	if (!error) {
	344	handle_t *handle;
	345	int retries = 0;
	346
	347	retry:
1f54587b JK	348	handle = ext3_journal_start(inode,
1f54587b JK	349	EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
1da177e4 LT	350	if (IS_ERR(handle)) {
	351	error = PTR_ERR(handle);
	352	ext3_std_error(inode->i_sb, error);
	353	goto out;
	354	}
	355	error = ext3_set_acl(handle, inode, ACL_TYPE_ACCESS, clone);
	356	ext3_journal_stop(handle);
	357	if (error == -ENOSPC &&
	358	ext3_should_retry_alloc(inode->i_sb, &retries))
	359	goto retry;
	360	}
	361	out:
	362	posix_acl_release(clone);
	363	return error;
	364	}
	365
	366	/*
	367	* Extended attribute handlers
	368	*/
	369	static size_t
431547b3 CH	370	ext3_xattr_list_acl_access(struct dentry dentry, char list, size_t list_len,
431547b3 CH	371	const char *name, size_t name_len, int type)
1da177e4	372	{
9a59f452	373	const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
1da177e4	374
431547b3	375	if (!test_opt(dentry->d_sb, POSIX_ACL))
1da177e4 LT	376	return 0;
1da177e4 LT	377	if (list && size <= list_len)
9a59f452	378	memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
1da177e4 LT	379	return size;
	380	}
	381
	382	static size_t
431547b3 CH	383	ext3_xattr_list_acl_default(struct dentry dentry, char list, size_t list_len,
431547b3 CH	384	const char *name, size_t name_len, int type)
1da177e4	385	{
9a59f452	386	const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
1da177e4	387
431547b3	388	if (!test_opt(dentry->d_sb, POSIX_ACL))
1da177e4 LT	389	return 0;
1da177e4 LT	390	if (list && size <= list_len)
9a59f452	391	memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
1da177e4 LT	392	return size;
	393	}
	394
	395	static int
431547b3 CH	396	ext3_xattr_get_acl(struct dentry dentry, const char name, void *buffer,
431547b3 CH	397	size_t size, int type)
1da177e4 LT	398	{
	399	struct posix_acl *acl;
	400	int error;
	401
431547b3 CH	402	if (strcmp(name, "") != 0)
	403	return -EINVAL;
	404	if (!test_opt(dentry->d_sb, POSIX_ACL))
1da177e4 LT	405	return -EOPNOTSUPP;
1da177e4 LT	406
431547b3	407	acl = ext3_get_acl(dentry->d_inode, type);
1da177e4 LT	408	if (IS_ERR(acl))
	409	return PTR_ERR(acl);
	410	if (acl == NULL)
	411	return -ENODATA;
	412	error = posix_acl_to_xattr(acl, buffer, size);
	413	posix_acl_release(acl);
	414
	415	return error;
	416	}
	417
	418	static int
431547b3 CH	419	ext3_xattr_set_acl(struct dentry dentry, const char name, const void *value,
431547b3 CH	420	size_t size, int flags, int type)
1da177e4	421	{
431547b3	422	struct inode *inode = dentry->d_inode;
1da177e4 LT	423	handle_t *handle;
	424	struct posix_acl *acl;
	425	int error, retries = 0;
	426
431547b3 CH	427	if (strcmp(name, "") != 0)
431547b3 CH	428	return -EINVAL;
1da177e4 LT	429	if (!test_opt(inode->i_sb, POSIX_ACL))
1da177e4 LT	430	return -EOPNOTSUPP;
3bd858ab	431	if (!is_owner_or_cap(inode))
1da177e4 LT	432	return -EPERM;
	433
	434	if (value) {
	435	acl = posix_acl_from_xattr(value, size);
	436	if (IS_ERR(acl))
	437	return PTR_ERR(acl);
	438	else if (acl) {
	439	error = posix_acl_valid(acl);
	440	if (error)
	441	goto release_and_out;
	442	}
	443	} else
	444	acl = NULL;
	445
	446	retry:
1f54587b	447	handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
1da177e4 LT	448	if (IS_ERR(handle))
	449	return PTR_ERR(handle);
	450	error = ext3_set_acl(handle, inode, type, acl);
	451	ext3_journal_stop(handle);
	452	if (error == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
	453	goto retry;
	454
	455	release_and_out:
	456	posix_acl_release(acl);
	457	return error;
	458	}
	459
d1f21049	460	const struct xattr_handler ext3_xattr_acl_access_handler = {
9a59f452	461	.prefix = POSIX_ACL_XATTR_ACCESS,
431547b3	462	.flags = ACL_TYPE_ACCESS,
1da177e4	463	.list = ext3_xattr_list_acl_access,
431547b3 CH	464	.get = ext3_xattr_get_acl,
431547b3 CH	465	.set = ext3_xattr_set_acl,
1da177e4 LT	466	};
1da177e4 LT	467
d1f21049	468	const struct xattr_handler ext3_xattr_acl_default_handler = {
9a59f452	469	.prefix = POSIX_ACL_XATTR_DEFAULT,
431547b3	470	.flags = ACL_TYPE_DEFAULT,
1da177e4	471	.list = ext3_xattr_list_acl_default,
431547b3 CH	472	.get = ext3_xattr_get_acl,
431547b3 CH	473	.set = ext3_xattr_set_acl,
1da177e4	474	};