[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/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_KERNEL);
	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 = (ext3_acl_header *)kmalloc(sizeof(ext3_acl_header) +
		acl->a_count * sizeof(ext3_acl_entry), GFP_KERNEL);
	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);
}

static inline struct posix_acl *
ext3_iget_acl(struct inode *inode, struct posix_acl **i_acl)
{
	struct posix_acl *acl = EXT3_ACL_NOT_CACHED;

	spin_lock(&inode->i_lock);
	if (*i_acl != EXT3_ACL_NOT_CACHED)
		acl = posix_acl_dup(*i_acl);
	spin_unlock(&inode->i_lock);

	return acl;
}

static inline void
ext3_iset_acl(struct inode *inode, struct posix_acl **i_acl,
                  struct posix_acl *acl)
{
	spin_lock(&inode->i_lock);
	if (*i_acl != EXT3_ACL_NOT_CACHED)
		posix_acl_release(*i_acl);
	*i_acl = posix_acl_dup(acl);
	spin_unlock(&inode->i_lock);
}

/*
 * Inode operation get_posix_acl().
 *
 * inode->i_sem: don't care
 */
static struct posix_acl *
ext3_get_acl(struct inode *inode, int type)
{
	struct ext3_inode_info *ei = EXT3_I(inode);
	int name_index;
	char *value = NULL;
	struct posix_acl *acl;
	int retval;

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

	switch(type) {
		case ACL_TYPE_ACCESS:
			acl = ext3_iget_acl(inode, &ei->i_acl);
			if (acl != EXT3_ACL_NOT_CACHED)
				return acl;
			name_index = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS;
			break;

		case ACL_TYPE_DEFAULT:
			acl = ext3_iget_acl(inode, &ei->i_default_acl);
			if (acl != EXT3_ACL_NOT_CACHED)
				return acl;
			name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
			break;

		default:
			return ERR_PTR(-EINVAL);
	}
	retval = ext3_xattr_get(inode, name_index, "", NULL, 0);
	if (retval > 0) {
		value = kmalloc(retval, GFP_KERNEL);
		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)) {
		switch(type) {
			case ACL_TYPE_ACCESS:
				ext3_iset_acl(inode, &ei->i_acl, acl);
				break;

			case ACL_TYPE_DEFAULT:
				ext3_iset_acl(inode, &ei->i_default_acl, acl);
				break;
		}
	}
	return acl;
}

/*
 * Set the access or default ACL of an inode.
 *
 * inode->i_sem: down unless called from ext3_new_inode
 */
static int
ext3_set_acl(handle_t *handle, struct inode *inode, int type,
	     struct posix_acl *acl)
{
	struct ext3_inode_info *ei = EXT3_I(inode);
	int name_index;
	void *value = NULL;
	size_t size;
	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;
					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) {
		switch(type) {
			case ACL_TYPE_ACCESS:
				ext3_iset_acl(inode, &ei->i_acl, acl);
				break;

			case ACL_TYPE_DEFAULT:
				ext3_iset_acl(inode, &ei->i_default_acl, acl);
				break;
		}
	}
	return error;
}

static 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;
}

int
ext3_permission(struct inode *inode, int mask, struct nameidata *nd)
{
	return generic_permission(inode, mask, ext3_check_acl);
}

/*
 * Initialize the ACLs of a new inode. Called from ext3_new_inode.
 *
 * dir->i_sem: down
 * inode->i_sem: 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->fs->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_KERNEL);
		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_sem: 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);
		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 inode *inode, char *list, size_t list_len,
			   const char *name, size_t name_len)
{
	const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);

	if (!test_opt(inode->i_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 inode *inode, char *list, size_t list_len,
			    const char *name, size_t name_len)
{
	const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);

	if (!test_opt(inode->i_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 inode *inode, int type, void *buffer, size_t size)
{
	struct posix_acl *acl;
	int error;

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

	acl = ext3_get_acl(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_get_acl_access(struct inode *inode, const char *name,
			  void *buffer, size_t size)
{
	if (strcmp(name, "") != 0)
		return -EINVAL;
	return ext3_xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size);
}

static int
ext3_xattr_get_acl_default(struct inode *inode, const char *name,
			   void *buffer, size_t size)
{
	if (strcmp(name, "") != 0)
		return -EINVAL;
	return ext3_xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size);
}

static int
ext3_xattr_set_acl(struct inode *inode, int type, const void *value,
		   size_t size)
{
	handle_t *handle;
	struct posix_acl *acl;
	int error, retries = 0;

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

static int
ext3_xattr_set_acl_access(struct inode *inode, const char *name,
			  const void *value, size_t size, int flags)
{
	if (strcmp(name, "") != 0)
		return -EINVAL;
	return ext3_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
}

static int
ext3_xattr_set_acl_default(struct inode *inode, const char *name,
			   const void *value, size_t size, int flags)
{
	if (strcmp(name, "") != 0)
		return -EINVAL;
	return ext3_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
}

struct xattr_handler ext3_xattr_acl_access_handler = {
	.prefix	= POSIX_ACL_XATTR_ACCESS,
	.list	= ext3_xattr_list_acl_access,
	.get	= ext3_xattr_get_acl_access,
	.set	= ext3_xattr_set_acl_access,
};

struct xattr_handler ext3_xattr_acl_default_handler = {
	.prefix	= POSIX_ACL_XATTR_DEFAULT,
	.list	= ext3_xattr_list_acl_default,
	.get	= ext3_xattr_get_acl_default,
	.set	= ext3_xattr_set_acl_default,
};
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>
	10	#include <linux/fs.h>
	11	#include <linux/ext3_jbd.h>
	12	#include <linux/ext3_fs.h>
	13	#include "xattr.h"
	14	#include "acl.h"
	15
	16	/*
	17	* Convert from filesystem to in-memory representation.
	18	*/
	19	static struct posix_acl *
	20	ext3_acl_from_disk(const void *value, size_t size)
	21	{
	22	const char end = (char )value + size;
	23	int n, count;
	24	struct posix_acl *acl;
	25
	26	if (!value)
	27	return NULL;
	28	if (size < sizeof(ext3_acl_header))
	29	return ERR_PTR(-EINVAL);
	30	if (((ext3_acl_header *)value)->a_version !=
	31	cpu_to_le32(EXT3_ACL_VERSION))
	32	return ERR_PTR(-EINVAL);
	33	value = (char *)value + sizeof(ext3_acl_header);
	34	count = ext3_acl_count(size);
	35	if (count < 0)
	36	return ERR_PTR(-EINVAL);
	37	if (count == 0)
	38	return NULL;
	39	acl = posix_acl_alloc(count, GFP_KERNEL);
	40	if (!acl)
	41	return ERR_PTR(-ENOMEM);
	42	for (n=0; n < count; n++) {
	43	ext3_acl_entry *entry =
	44	(ext3_acl_entry *)value;
	45	if ((char *)value + sizeof(ext3_acl_entry_short) > end)
	46	goto fail;
	47	acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
	48	acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
	49	switch(acl->a_entries[n].e_tag) {
	50	case ACL_USER_OBJ:
	51	case ACL_GROUP_OBJ:
	52	case ACL_MASK:
	53	case ACL_OTHER:
	54	value = (char *)value +
	55	sizeof(ext3_acl_entry_short);
	56	acl->a_entries[n].e_id = ACL_UNDEFINED_ID;
	57	break;
	58
	59	case ACL_USER:
	60	case ACL_GROUP:
	61	value = (char *)value + sizeof(ext3_acl_entry);
	62	if ((char *)value > end)
	63	goto fail;
	64	acl->a_entries[n].e_id =
65	le32_to_cpu(entry->e_id);
66	break;
67
68	default:
69	goto fail;
70	}
71	}
72	if (value != end)
73	goto fail;
74	return acl;
75
76	fail:
77	posix_acl_release(acl);
78	return ERR_PTR(-EINVAL);
79	}
80
81	/*
82	* Convert from in-memory to filesystem representation.
83	*/
84	static void *
85	ext3_acl_to_disk(const struct posix_acl acl, size_t size)
86	{
87	ext3_acl_header *ext_acl;
88	char *e;
89	size_t n;
90
91	*size = ext3_acl_size(acl->a_count);
92	ext_acl = (ext3_acl_header *)kmalloc(sizeof(ext3_acl_header) +
93	acl->a_count * sizeof(ext3_acl_entry), GFP_KERNEL);
94	if (!ext_acl)
95	return ERR_PTR(-ENOMEM);
96	ext_acl->a_version = cpu_to_le32(EXT3_ACL_VERSION);
97	e = (char *)ext_acl + sizeof(ext3_acl_header);
98	for (n=0; n < acl->a_count; n++) {
99	ext3_acl_entry entry = (ext3_acl_entry )e;
100	entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
101	entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
102	switch(acl->a_entries[n].e_tag) {
103	case ACL_USER:
104	case ACL_GROUP:
105	entry->e_id =
106	cpu_to_le32(acl->a_entries[n].e_id);
107	e += sizeof(ext3_acl_entry);
108	break;
109
110	case ACL_USER_OBJ:
111	case ACL_GROUP_OBJ:
112	case ACL_MASK:
113	case ACL_OTHER:
114	e += sizeof(ext3_acl_entry_short);
115	break;
116
117	default:
118	goto fail;
119	}
120	}
121	return (char *)ext_acl;
122
123	fail:
124	kfree(ext_acl);
125	return ERR_PTR(-EINVAL);
126	}
127
128	static inline struct posix_acl *
129	ext3_iget_acl(struct inode inode, struct posix_acl *i_acl)
130	{
131	struct posix_acl *acl = EXT3_ACL_NOT_CACHED;
132
133	spin_lock(&inode->i_lock);
134	if (*i_acl != EXT3_ACL_NOT_CACHED)
135	acl = posix_acl_dup(*i_acl);
136	spin_unlock(&inode->i_lock);
137
138	return acl;
139	}
140
141	static inline void
142	ext3_iset_acl(struct inode inode, struct posix_acl *i_acl,
143	struct posix_acl *acl)
144	{
145	spin_lock(&inode->i_lock);
146	if (*i_acl != EXT3_ACL_NOT_CACHED)
147	posix_acl_release(*i_acl);
148	*i_acl = posix_acl_dup(acl);
149	spin_unlock(&inode->i_lock);
150	}
151
152	/*
153	* Inode operation get_posix_acl().
154	*
155	* inode->i_sem: don't care
156	*/
157	static struct posix_acl *
158	ext3_get_acl(struct inode *inode, int type)
159	{
160	struct ext3_inode_info *ei = EXT3_I(inode);
161	int name_index;
162	char *value = NULL;
163	struct posix_acl *acl;
164	int retval;
165
166	if (!test_opt(inode->i_sb, POSIX_ACL))
167	return NULL;
168
169	switch(type) {
170	case ACL_TYPE_ACCESS:
171	acl = ext3_iget_acl(inode, &ei->i_acl);
172	if (acl != EXT3_ACL_NOT_CACHED)
173	return acl;
174	name_index = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS;
175	break;
176
177	case ACL_TYPE_DEFAULT:
178	acl = ext3_iget_acl(inode, &ei->i_default_acl);
179	if (acl != EXT3_ACL_NOT_CACHED)
180	return acl;
181	name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
182	break;
183
184	default:
185	return ERR_PTR(-EINVAL);
186	}
187	retval = ext3_xattr_get(inode, name_index, "", NULL, 0);
188	if (retval > 0) {
189	value = kmalloc(retval, GFP_KERNEL);
190	if (!value)
191	return ERR_PTR(-ENOMEM);
192	retval = ext3_xattr_get(inode, name_index, "", value, retval);
193	}
194	if (retval > 0)
195	acl = ext3_acl_from_disk(value, retval);
196	else if (retval == -ENODATA \|\| retval == -ENOSYS)
197	acl = NULL;
198	else
199	acl = ERR_PTR(retval);
200	kfree(value);
201
202	if (!IS_ERR(acl)) {
203	switch(type) {
204	case ACL_TYPE_ACCESS:
205	ext3_iset_acl(inode, &ei->i_acl, acl);
206	break;
207
208	case ACL_TYPE_DEFAULT:
209	ext3_iset_acl(inode, &ei->i_default_acl, acl);
210	break;
211	}
212	}
213	return acl;
214	}
215
216	/*
217	* Set the access or default ACL of an inode.
218	*
219	* inode->i_sem: down unless called from ext3_new_inode
220	*/
221	static int
222	ext3_set_acl(handle_t handle, struct inode inode, int type,
223	struct posix_acl *acl)
224	{
225	struct ext3_inode_info *ei = EXT3_I(inode);
226	int name_index;
227	void *value = NULL;
228	size_t size;
229	int error;
230
231	if (S_ISLNK(inode->i_mode))
232	return -EOPNOTSUPP;
233
234	switch(type) {
235	case ACL_TYPE_ACCESS:
236	name_index = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS;
237	if (acl) {
238	mode_t mode = inode->i_mode;
239	error = posix_acl_equiv_mode(acl, &mode);
240	if (error < 0)
241	return error;
242	else {
243	inode->i_mode = mode;
244	ext3_mark_inode_dirty(handle, inode);
245	if (error == 0)
246	acl = NULL;
247	}
248	}
249	break;
250
251	case ACL_TYPE_DEFAULT:
252	name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
253	if (!S_ISDIR(inode->i_mode))
254	return acl ? -EACCES : 0;
255	break;
256
257	default:
258	return -EINVAL;
259	}
260	if (acl) {
261	value = ext3_acl_to_disk(acl, &size);
262	if (IS_ERR(value))
263	return (int)PTR_ERR(value);
264	}
265
266	error = ext3_xattr_set_handle(handle, inode, name_index, "",
267	value, size, 0);
268
269	kfree(value);
270	if (!error) {
271	switch(type) {
272	case ACL_TYPE_ACCESS:
273	ext3_iset_acl(inode, &ei->i_acl, acl);
274	break;
275
276	case ACL_TYPE_DEFAULT:
277	ext3_iset_acl(inode, &ei->i_default_acl, acl);
278	break;
279	}
280	}
281	return error;
282	}
283
284	static int
285	ext3_check_acl(struct inode *inode, int mask)
286	{
287	struct posix_acl *acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
288
e493073d AM	289	if (IS_ERR(acl))
e493073d AM	290	return PTR_ERR(acl);
1da177e4 LT	291	if (acl) {
	292	int error = posix_acl_permission(inode, acl, mask);
	293	posix_acl_release(acl);
	294	return error;
	295	}
	296
	297	return -EAGAIN;
	298	}
	299
	300	int
	301	ext3_permission(struct inode inode, int mask, struct nameidata nd)
	302	{
	303	return generic_permission(inode, mask, ext3_check_acl);
	304	}
	305
	306	/*
	307	* Initialize the ACLs of a new inode. Called from ext3_new_inode.
	308	*
	309	* dir->i_sem: down
	310	* inode->i_sem: up (access to inode is still exclusive)
	311	*/
	312	int
	313	ext3_init_acl(handle_t handle, struct inode inode, struct inode *dir)
	314	{
	315	struct posix_acl *acl = NULL;
	316	int error = 0;
	317
	318	if (!S_ISLNK(inode->i_mode)) {
	319	if (test_opt(dir->i_sb, POSIX_ACL)) {
	320	acl = ext3_get_acl(dir, ACL_TYPE_DEFAULT);
	321	if (IS_ERR(acl))
	322	return PTR_ERR(acl);
	323	}
	324	if (!acl)
	325	inode->i_mode &= ~current->fs->umask;
	326	}
	327	if (test_opt(inode->i_sb, POSIX_ACL) && acl) {
	328	struct posix_acl *clone;
	329	mode_t mode;
	330
	331	if (S_ISDIR(inode->i_mode)) {
	332	error = ext3_set_acl(handle, inode,
	333	ACL_TYPE_DEFAULT, acl);
	334	if (error)
	335	goto cleanup;
	336	}
	337	clone = posix_acl_clone(acl, GFP_KERNEL);
	338	error = -ENOMEM;
	339	if (!clone)
	340	goto cleanup;
	341
	342	mode = inode->i_mode;
	343	error = posix_acl_create_masq(clone, &mode);
	344	if (error >= 0) {
	345	inode->i_mode = mode;
	346	if (error > 0) {
	347	/* This is an extended ACL */
	348	error = ext3_set_acl(handle, inode,
	349	ACL_TYPE_ACCESS, clone);
	350	}
	351	}
	352	posix_acl_release(clone);
	353	}
	354	cleanup:
355	posix_acl_release(acl);
356	return error;
357	}
358
359	/*
360	* Does chmod for an inode that may have an Access Control List. The
361	* inode->i_mode field must be updated to the desired value by the caller
362	* before calling this function.
363	* Returns 0 on success, or a negative error number.
364	*
365	* We change the ACL rather than storing some ACL entries in the file
366	* mode permission bits (which would be more efficient), because that
367	* would break once additional permissions (like ACL_APPEND, ACL_DELETE
368	* for directories) are added. There are no more bits available in the
369	* file mode.
370	*
371	* inode->i_sem: down
372	*/
373	int
374	ext3_acl_chmod(struct inode *inode)
375	{
376	struct posix_acl acl, clone;
377	int error;
378
379	if (S_ISLNK(inode->i_mode))
380	return -EOPNOTSUPP;
381	if (!test_opt(inode->i_sb, POSIX_ACL))
382	return 0;
383	acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
384	if (IS_ERR(acl) \|\| !acl)
385	return PTR_ERR(acl);
386	clone = posix_acl_clone(acl, GFP_KERNEL);
387	posix_acl_release(acl);
388	if (!clone)
389	return -ENOMEM;
390	error = posix_acl_chmod_masq(clone, inode->i_mode);
391	if (!error) {
392	handle_t *handle;
393	int retries = 0;
394
395	retry:
396	handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS);
397	if (IS_ERR(handle)) {
398	error = PTR_ERR(handle);
399	ext3_std_error(inode->i_sb, error);
400	goto out;
401	}
402	error = ext3_set_acl(handle, inode, ACL_TYPE_ACCESS, clone);
403	ext3_journal_stop(handle);
404	if (error == -ENOSPC &&
405	ext3_should_retry_alloc(inode->i_sb, &retries))
406	goto retry;
407	}
408	out:
409	posix_acl_release(clone);
410	return error;
411	}
412
413	/*
414	* Extended attribute handlers
415	*/
416	static size_t
417	ext3_xattr_list_acl_access(struct inode inode, char list, size_t list_len,
418	const char *name, size_t name_len)
419	{
9a59f452	420	const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
1da177e4 LT	421
	422	if (!test_opt(inode->i_sb, POSIX_ACL))
	423	return 0;
	424	if (list && size <= list_len)
9a59f452	425	memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
1da177e4 LT	426	return size;
	427	}
	428
	429	static size_t
	430	ext3_xattr_list_acl_default(struct inode inode, char list, size_t list_len,
	431	const char *name, size_t name_len)
	432	{
9a59f452	433	const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
1da177e4 LT	434
	435	if (!test_opt(inode->i_sb, POSIX_ACL))
	436	return 0;
	437	if (list && size <= list_len)
9a59f452	438	memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
1da177e4 LT	439	return size;
	440	}
	441
	442	static int
	443	ext3_xattr_get_acl(struct inode inode, int type, void buffer, size_t size)
	444	{
	445	struct posix_acl *acl;
	446	int error;
	447
	448	if (!test_opt(inode->i_sb, POSIX_ACL))
	449	return -EOPNOTSUPP;
	450
	451	acl = ext3_get_acl(inode, type);
	452	if (IS_ERR(acl))
	453	return PTR_ERR(acl);
	454	if (acl == NULL)
	455	return -ENODATA;
	456	error = posix_acl_to_xattr(acl, buffer, size);
	457	posix_acl_release(acl);
	458
	459	return error;
	460	}
	461
	462	static int
	463	ext3_xattr_get_acl_access(struct inode inode, const char name,
	464	void *buffer, size_t size)
	465	{
	466	if (strcmp(name, "") != 0)
	467	return -EINVAL;
	468	return ext3_xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size);
	469	}
	470
	471	static int
	472	ext3_xattr_get_acl_default(struct inode inode, const char name,
	473	void *buffer, size_t size)
	474	{
	475	if (strcmp(name, "") != 0)
	476	return -EINVAL;
	477	return ext3_xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size);
	478	}
	479
	480	static int
	481	ext3_xattr_set_acl(struct inode inode, int type, const void value,
	482	size_t size)
	483	{
	484	handle_t *handle;
	485	struct posix_acl *acl;
	486	int error, retries = 0;
	487
	488	if (!test_opt(inode->i_sb, POSIX_ACL))
	489	return -EOPNOTSUPP;
	490	if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
	491	return -EPERM;
	492
	493	if (value) {
	494	acl = posix_acl_from_xattr(value, size);
	495	if (IS_ERR(acl))
	496	return PTR_ERR(acl);
	497	else if (acl) {
	498	error = posix_acl_valid(acl);
	499	if (error)
	500	goto release_and_out;
	501	}
	502	} else
503	acl = NULL;
504
505	retry:
506	handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS);
507	if (IS_ERR(handle))
508	return PTR_ERR(handle);
509	error = ext3_set_acl(handle, inode, type, acl);
510	ext3_journal_stop(handle);
511	if (error == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
512	goto retry;
513
514	release_and_out:
515	posix_acl_release(acl);
516	return error;
517	}
518
519	static int
520	ext3_xattr_set_acl_access(struct inode inode, const char name,
521	const void *value, size_t size, int flags)
522	{
523	if (strcmp(name, "") != 0)
524	return -EINVAL;
525	return ext3_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
526	}
527
528	static int
529	ext3_xattr_set_acl_default(struct inode inode, const char name,
530	const void *value, size_t size, int flags)
531	{
532	if (strcmp(name, "") != 0)
533	return -EINVAL;
534	return ext3_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
535	}
536
537	struct xattr_handler ext3_xattr_acl_access_handler = {
9a59f452	538	.prefix = POSIX_ACL_XATTR_ACCESS,
1da177e4 LT	539	.list = ext3_xattr_list_acl_access,
	540	.get = ext3_xattr_get_acl_access,
	541	.set = ext3_xattr_set_acl_access,
	542	};
	543
	544	struct xattr_handler ext3_xattr_acl_default_handler = {
9a59f452	545	.prefix = POSIX_ACL_XATTR_DEFAULT,
1da177e4 LT	546	.list = ext3_xattr_list_acl_default,
	547	.get = ext3_xattr_get_acl_default,
	548	.set = ext3_xattr_set_acl_default,
	549	};