[linux-2.6-block.git] / fs / btrfs / acl.c

/*
 * Copyright (C) 2007 Red Hat.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include <linux/fs.h>
#include <linux/string.h>
#include <linux/xattr.h>
#include <linux/posix_acl_xattr.h>
#include <linux/posix_acl.h>
#include <linux/sched.h>

#include "ctree.h"
#include "btrfs_inode.h"
#include "xattr.h"

static void btrfs_update_cached_acl(struct inode *inode,
				    struct posix_acl **p_acl,
				    struct posix_acl *acl)
{
	spin_lock(&inode->i_lock);
	if (*p_acl && *p_acl != BTRFS_ACL_NOT_CACHED)
		posix_acl_release(*p_acl);
	*p_acl = posix_acl_dup(acl);
	spin_unlock(&inode->i_lock);
}

static struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
{
	int size, name_index;
	char *value = NULL;
	struct posix_acl *acl = NULL, **p_acl;

	switch (type) {
	case ACL_TYPE_ACCESS:
		name_index = BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS;
		p_acl = &BTRFS_I(inode)->i_acl;
		break;
	case ACL_TYPE_DEFAULT:
		name_index = BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT;
		p_acl = &BTRFS_I(inode)->i_default_acl;
		break;
	default:
		return ERR_PTR(-EINVAL);
	}

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

	if (acl)
		return acl;


	size = btrfs_xattr_get(inode, name_index, "", NULL, 0);
	if (size > 0) {
		value = kzalloc(size, GFP_NOFS);
		if (!value)
			return ERR_PTR(-ENOMEM);
		size = btrfs_xattr_get(inode, name_index, "", value, size);
		if (size > 0) {
			acl = posix_acl_from_xattr(value, size);
			btrfs_update_cached_acl(inode, p_acl, acl);
		}
		kfree(value);
	} else if (size == -ENOENT) {
		acl = NULL;
		btrfs_update_cached_acl(inode, p_acl, acl);
	}

	return acl;
}

static int btrfs_xattr_get_acl(struct inode *inode, int type,
			       void *value, size_t size)
{
	struct posix_acl *acl;
	int ret = 0;

	acl = btrfs_get_acl(inode, type);

	if (IS_ERR(acl))
		return PTR_ERR(acl);
	if (acl == NULL)
		return -ENODATA;
	ret = posix_acl_to_xattr(acl, value, size);
	posix_acl_release(acl);

	return ret;
}

/*
 * Needs to be called with fs_mutex held
 */
static int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
{
	int ret, name_index = 0, size = 0;
	struct posix_acl **p_acl;
	char *value = NULL;
	mode_t mode;

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

	switch (type) {
	case ACL_TYPE_ACCESS:
		mode = inode->i_mode;
		ret = posix_acl_equiv_mode(acl, &mode);
		if (ret < 0)
			return ret;
		ret = 0;
		inode->i_mode = mode;
		name_index = BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS;
		p_acl = &BTRFS_I(inode)->i_acl;
		break;
	case ACL_TYPE_DEFAULT:
		if (!S_ISDIR(inode->i_mode))
			return acl ? -EINVAL : 0;
		name_index = BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT;
		p_acl = &BTRFS_I(inode)->i_default_acl;
		break;
	default:
		return -EINVAL;
	}

	if (acl) {
		size = posix_acl_xattr_size(acl->a_count);
		value = kmalloc(size, GFP_NOFS);
		if (!value) {
			ret = -ENOMEM;
			goto out;
		}

		ret = posix_acl_to_xattr(acl, value, size);
		if (ret < 0)
			goto out;
	}

	ret = btrfs_xattr_set(inode, name_index, "", value, size, 0);

out:
	if (value)
		kfree(value);

	if (!ret)
		btrfs_update_cached_acl(inode, p_acl, acl);

	return ret;
}

static int btrfs_xattr_set_acl(struct inode *inode, int type,
			       const void *value, size_t size)
{
	int ret = 0;
	struct posix_acl *acl = NULL;

	if (value) {
		acl = posix_acl_from_xattr(value, size);
		if (acl == NULL) {
			value = NULL;
			size = 0;
		} else if (IS_ERR(acl)) {
			return PTR_ERR(acl);
		}
	}

	ret = btrfs_set_acl(inode, acl, type);

	posix_acl_release(acl);

	return ret;
}


static int btrfs_xattr_acl_access_get(struct inode *inode, const char *name,
				      void *value, size_t size)
{
	return btrfs_xattr_get_acl(inode, ACL_TYPE_ACCESS, value, size);
}

static int btrfs_xattr_acl_access_set(struct inode *inode, const char *name,
				      const void *value, size_t size, int flags)
{
	return btrfs_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
}

static int btrfs_xattr_acl_default_get(struct inode *inode, const char *name,
				       void *value, size_t size)
{
	return btrfs_xattr_get_acl(inode, ACL_TYPE_DEFAULT, value, size);
}

static int btrfs_xattr_acl_default_set(struct inode *inode, const char *name,
				       const void *value, size_t size, int flags)
{
	return btrfs_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
}

int btrfs_check_acl(struct inode *inode, int mask)
{
	struct posix_acl *acl;
	int error = -EAGAIN;

	acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);

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

	return error;
}

/*
 * btrfs_init_acl is already generally called under fs_mutex, so the locking
 * stuff has been fixed to work with that.  If the locking stuff changes, we
 * need to re-evaluate the acl locking stuff.
 */
int btrfs_init_acl(struct inode *inode, struct inode *dir)
{
	struct posix_acl *acl = NULL;
	int ret = 0;

	/* this happens with subvols */
	if (!dir)
		return 0;

	if (!S_ISLNK(inode->i_mode)) {
		if (IS_POSIXACL(dir)) {
			acl = btrfs_get_acl(dir, ACL_TYPE_DEFAULT);
			if (IS_ERR(acl))
				return PTR_ERR(acl);
		}

		if (!acl)
			inode->i_mode &= ~current->fs->umask;
	}

	if (IS_POSIXACL(dir) && acl) {
		struct posix_acl *clone;
		mode_t mode;

		if (S_ISDIR(inode->i_mode)) {
			ret = btrfs_set_acl(inode, acl, ACL_TYPE_DEFAULT);
			if (ret)
				goto failed;
		}
		clone = posix_acl_clone(acl, GFP_NOFS);
		ret = -ENOMEM;
		if (!clone)
			goto failed;

		mode = inode->i_mode;
		ret = posix_acl_create_masq(clone, &mode);
		if (ret >= 0) {
			inode->i_mode = mode;
			if (ret > 0) {
				/* we need an acl */
				ret = btrfs_set_acl(inode, clone,
						    ACL_TYPE_ACCESS);
			}
		}
	}
failed:
	posix_acl_release(acl);

	return ret;
}

int btrfs_acl_chmod(struct inode *inode)
{
	struct posix_acl *acl, *clone;
	int ret = 0;

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

	if (!IS_POSIXACL(inode))
		return 0;

	acl = btrfs_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;

	ret = posix_acl_chmod_masq(clone, inode->i_mode);
	if (!ret)
		ret = btrfs_set_acl(inode, clone, ACL_TYPE_ACCESS);

	posix_acl_release(clone);

	return ret;
}

struct xattr_handler btrfs_xattr_acl_default_handler = {
	.prefix = POSIX_ACL_XATTR_DEFAULT,
	.list	= btrfs_xattr_generic_list,
	.get	= btrfs_xattr_acl_default_get,
	.set	= btrfs_xattr_acl_default_set,
};

struct xattr_handler btrfs_xattr_acl_access_handler = {
	.prefix = POSIX_ACL_XATTR_ACCESS,
	.list	= btrfs_xattr_generic_list,
	.get	= btrfs_xattr_acl_access_get,
	.set	= btrfs_xattr_acl_access_set,
};
Commit	Line	Data
5103e947 JB	1	/*
	2	* Copyright (C) 2007 Red Hat. All rights reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public
	6	* License v2 as published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope that it will be useful,
	9	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	11	* General Public License for more details.
	12	*
	13	* You should have received a copy of the GNU General Public
	14	* License along with this program; if not, write to the
	15	* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	16	* Boston, MA 021110-1307, USA.
	17	*/
	18
	19	#include <linux/fs.h>
	20	#include <linux/string.h>
	21	#include <linux/xattr.h>
	22	#include <linux/posix_acl_xattr.h>
33268eaf	23	#include <linux/posix_acl.h>
c1e32da6	24	#include <linux/sched.h>
33268eaf	25
5103e947	26	#include "ctree.h"
33268eaf	27	#include "btrfs_inode.h"
5103e947	28	#include "xattr.h"
33268eaf JB	29
	30	static void btrfs_update_cached_acl(struct inode *inode,
	31	struct posix_acl **p_acl,
	32	struct posix_acl *acl)
	33	{
	34	spin_lock(&inode->i_lock);
	35	if (p_acl && p_acl != BTRFS_ACL_NOT_CACHED)
	36	posix_acl_release(*p_acl);
	37	*p_acl = posix_acl_dup(acl);
	38	spin_unlock(&inode->i_lock);
	39	}
	40
	41	static struct posix_acl btrfs_get_acl(struct inode inode, int type)
	42	{
	43	int size, name_index;
	44	char *value = NULL;
	45	struct posix_acl acl = NULL, *p_acl;
	46
	47	switch (type) {
	48	case ACL_TYPE_ACCESS:
	49	name_index = BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS;
	50	p_acl = &BTRFS_I(inode)->i_acl;
	51	break;
	52	case ACL_TYPE_DEFAULT:
	53	name_index = BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT;
	54	p_acl = &BTRFS_I(inode)->i_default_acl;
	55	break;
	56	default:
	57	return ERR_PTR(-EINVAL);
	58	}
	59
	60	spin_lock(&inode->i_lock);
	61	if (*p_acl != BTRFS_ACL_NOT_CACHED)
	62	acl = posix_acl_dup(*p_acl);
	63	spin_unlock(&inode->i_lock);
	64
	65	if (acl)
	66	return acl;
	67
	68
	69	size = btrfs_xattr_get(inode, name_index, "", NULL, 0);
	70	if (size > 0) {
	71	value = kzalloc(size, GFP_NOFS);
	72	if (!value)
	73	return ERR_PTR(-ENOMEM);
	74	size = btrfs_xattr_get(inode, name_index, "", value, size);
	75	if (size > 0) {
	76	acl = posix_acl_from_xattr(value, size);
	77	btrfs_update_cached_acl(inode, p_acl, acl);
	78	}
	79	kfree(value);
	80	} else if (size == -ENOENT) {
	81	acl = NULL;
	82	btrfs_update_cached_acl(inode, p_acl, acl);
	83	}
	84
	85	return acl;
	86	}
	87
	88	static int btrfs_xattr_get_acl(struct inode *inode, int type,
	89	void *value, size_t size)
	90	{
	91	struct posix_acl *acl;
	92	int ret = 0;
93
94	acl = btrfs_get_acl(inode, type);
95
96	if (IS_ERR(acl))
97	return PTR_ERR(acl);
98	if (acl == NULL)
99	return -ENODATA;
100	ret = posix_acl_to_xattr(acl, value, size);
101	posix_acl_release(acl);
102
103	return ret;
104	}
105
106	/*
107	* Needs to be called with fs_mutex held
108	*/
109	static int btrfs_set_acl(struct inode inode, struct posix_acl acl, int type)
110	{
111	int ret, name_index = 0, size = 0;
112	struct posix_acl **p_acl;
113	char *value = NULL;
114	mode_t mode;
115
116	if (acl) {
117	ret = posix_acl_valid(acl);
118	if (ret < 0)
119	return ret;
120	ret = 0;
121	}
122
123	switch (type) {
124	case ACL_TYPE_ACCESS:
125	mode = inode->i_mode;
126	ret = posix_acl_equiv_mode(acl, &mode);
127	if (ret < 0)
128	return ret;
129	ret = 0;
130	inode->i_mode = mode;
131	name_index = BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS;
132	p_acl = &BTRFS_I(inode)->i_acl;
133	break;
134	case ACL_TYPE_DEFAULT:
135	if (!S_ISDIR(inode->i_mode))
136	return acl ? -EINVAL : 0;
137	name_index = BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT;
138	p_acl = &BTRFS_I(inode)->i_default_acl;
139	break;
140	default:
141	return -EINVAL;
142	}
143
144	if (acl) {
145	size = posix_acl_xattr_size(acl->a_count);
146	value = kmalloc(size, GFP_NOFS);
147	if (!value) {
148	ret = -ENOMEM;
149	goto out;
150	}
151
152	ret = posix_acl_to_xattr(acl, value, size);
153	if (ret < 0)
154	goto out;
155	}
156
157	ret = btrfs_xattr_set(inode, name_index, "", value, size, 0);
158
159	out:
160	if (value)
161	kfree(value);
162
163	if (!ret)
164	btrfs_update_cached_acl(inode, p_acl, acl);
165
166	return ret;
167	}
fb4bc1e0	168
744f52f9 Y	169	static int btrfs_xattr_set_acl(struct inode *inode, int type,
	170	const void *value, size_t size)
	171	{
	172	int ret = 0;
33268eaf	173	struct posix_acl *acl = NULL;
5103e947	174
744f52f9 Y	175	if (value) {
	176	acl = posix_acl_from_xattr(value, size);
	177	if (acl == NULL) {
	178	value = NULL;
	179	size = 0;
	180	} else if (IS_ERR(acl)) {
33268eaf	181	return PTR_ERR(acl);
744f52f9	182	}
744f52f9	183	}
1caf9342	184
33268eaf JB	185	ret = btrfs_set_acl(inode, acl, type);
	186
	187	posix_acl_release(acl);
	188
	189	return ret;
744f52f9	190	}
33268eaf JB	191
33268eaf JB	192
5103e947 JB	193	static int btrfs_xattr_acl_access_get(struct inode inode, const char name,
	194	void *value, size_t size)
	195	{
33268eaf	196	return btrfs_xattr_get_acl(inode, ACL_TYPE_ACCESS, value, size);
5103e947	197	}
33268eaf	198
5103e947 JB	199	static int btrfs_xattr_acl_access_set(struct inode inode, const char name,
	200	const void *value, size_t size, int flags)
	201	{
33268eaf	202	return btrfs_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
5103e947	203	}
33268eaf	204
5103e947 JB	205	static int btrfs_xattr_acl_default_get(struct inode inode, const char name,
	206	void *value, size_t size)
	207	{
33268eaf	208	return btrfs_xattr_get_acl(inode, ACL_TYPE_DEFAULT, value, size);
5103e947	209	}
33268eaf	210
5103e947 JB	211	static int btrfs_xattr_acl_default_set(struct inode inode, const char name,
	212	const void *value, size_t size, int flags)
	213	{
33268eaf JB	214	return btrfs_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
	215	}
	216
	217	int btrfs_check_acl(struct inode *inode, int mask)
	218	{
	219	struct posix_acl *acl;
	220	int error = -EAGAIN;
	221
	222	acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
	223
	224	if (IS_ERR(acl))
	225	return PTR_ERR(acl);
	226	if (acl) {
	227	error = posix_acl_permission(inode, acl, mask);
	228	posix_acl_release(acl);
	229	}
	230
	231	return error;
	232	}
	233
	234	/*
	235	* btrfs_init_acl is already generally called under fs_mutex, so the locking
	236	* stuff has been fixed to work with that. If the locking stuff changes, we
	237	* need to re-evaluate the acl locking stuff.
	238	*/
	239	int btrfs_init_acl(struct inode inode, struct inode dir)
	240	{
	241	struct posix_acl *acl = NULL;
	242	int ret = 0;
	243
	244	/* this happens with subvols */
	245	if (!dir)
	246	return 0;
	247
	248	if (!S_ISLNK(inode->i_mode)) {
	249	if (IS_POSIXACL(dir)) {
	250	acl = btrfs_get_acl(dir, ACL_TYPE_DEFAULT);
	251	if (IS_ERR(acl))
	252	return PTR_ERR(acl);
	253	}
	254
	255	if (!acl)
	256	inode->i_mode &= ~current->fs->umask;
	257	}
	258
	259	if (IS_POSIXACL(dir) && acl) {
	260	struct posix_acl *clone;
	261	mode_t mode;
	262
	263	if (S_ISDIR(inode->i_mode)) {
	264	ret = btrfs_set_acl(inode, acl, ACL_TYPE_DEFAULT);
	265	if (ret)
	266	goto failed;
	267	}
	268	clone = posix_acl_clone(acl, GFP_NOFS);
	269	ret = -ENOMEM;
	270	if (!clone)
	271	goto failed;
	272
	273	mode = inode->i_mode;
	274	ret = posix_acl_create_masq(clone, &mode);
	275	if (ret >= 0) {
	276	inode->i_mode = mode;
	277	if (ret > 0) {
278	/* we need an acl */
279	ret = btrfs_set_acl(inode, clone,
280	ACL_TYPE_ACCESS);
281	}
282	}
283	}
284	failed:
285	posix_acl_release(acl);
286
287	return ret;
288	}
289
290	int btrfs_acl_chmod(struct inode *inode)
291	{
292	struct posix_acl acl, clone;
293	int ret = 0;
294
295	if (S_ISLNK(inode->i_mode))
296	return -EOPNOTSUPP;
297
298	if (!IS_POSIXACL(inode))
299	return 0;
300
301	acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
302	if (IS_ERR(acl) \|\| !acl)
303	return PTR_ERR(acl);
304
305	clone = posix_acl_clone(acl, GFP_KERNEL);
306	posix_acl_release(acl);
307	if (!clone)
308	return -ENOMEM;
309
310	ret = posix_acl_chmod_masq(clone, inode->i_mode);
311	if (!ret)
312	ret = btrfs_set_acl(inode, clone, ACL_TYPE_ACCESS);
313
314	posix_acl_release(clone);
315
316	return ret;
5103e947	317	}
33268eaf	318
5103e947 JB	319	struct xattr_handler btrfs_xattr_acl_default_handler = {
	320	.prefix = POSIX_ACL_XATTR_DEFAULT,
	321	.list = btrfs_xattr_generic_list,
	322	.get = btrfs_xattr_acl_default_get,
	323	.set = btrfs_xattr_acl_default_set,
	324	};
	325
	326	struct xattr_handler btrfs_xattr_acl_access_handler = {
	327	.prefix = POSIX_ACL_XATTR_ACCESS,
	328	.list = btrfs_xattr_generic_list,
	329	.get = btrfs_xattr_acl_access_get,
	330	.set = btrfs_xattr_acl_access_set,
	331	};