[net-next-2.6.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"

#ifdef CONFIG_FS_POSIX_ACL

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;
	const char *name;
	char *value = NULL;
	struct posix_acl *acl = NULL, **p_acl;

	switch (type) {
	case ACL_TYPE_ACCESS:
		name = POSIX_ACL_XATTR_ACCESS;
		p_acl = &BTRFS_I(inode)->i_acl;
		break;
	case ACL_TYPE_DEFAULT:
		name = POSIX_ACL_XATTR_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_getxattr(inode, name, "", 0);
	if (size > 0) {
		value = kzalloc(size, GFP_NOFS);
		if (!value)
			return ERR_PTR(-ENOMEM);
		size = __btrfs_getxattr(inode, name, 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, size = 0;
	const char *name;
	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 = POSIX_ACL_XATTR_ACCESS;
		p_acl = &BTRFS_I(inode)->i_acl;
		break;
	case ACL_TYPE_DEFAULT:
		if (!S_ISDIR(inode->i_mode))
			return acl ? -EINVAL : 0;
		name = POSIX_ACL_XATTR_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_setxattr(inode, name, 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,
	.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,
	.get	= btrfs_xattr_acl_access_get,
	.set	= btrfs_xattr_acl_access_set,
};

#else /* CONFIG_FS_POSIX_ACL */

int btrfs_acl_chmod(struct inode *inode)
{
	return 0;
}

int btrfs_init_acl(struct inode *inode, struct inode *dir)
{
	return 0;
}

int btrfs_check_acl(struct inode *inode, int mask)
{
	return 0;
}

#endif /* CONFIG_FS_POSIX_ACL */
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	29
eab922ec JB	30	#ifdef CONFIG_FS_POSIX_ACL
eab922ec JB	31
33268eaf JB	32	static void btrfs_update_cached_acl(struct inode *inode,
	33	struct posix_acl **p_acl,
	34	struct posix_acl *acl)
	35	{
	36	spin_lock(&inode->i_lock);
	37	if (p_acl && p_acl != BTRFS_ACL_NOT_CACHED)
	38	posix_acl_release(*p_acl);
	39	*p_acl = posix_acl_dup(acl);
	40	spin_unlock(&inode->i_lock);
	41	}
	42
	43	static struct posix_acl btrfs_get_acl(struct inode inode, int type)
	44	{
95819c05 CH	45	int size;
95819c05 CH	46	const char *name;
33268eaf JB	47	char *value = NULL;
	48	struct posix_acl acl = NULL, *p_acl;
	49
	50	switch (type) {
	51	case ACL_TYPE_ACCESS:
95819c05	52	name = POSIX_ACL_XATTR_ACCESS;
33268eaf JB	53	p_acl = &BTRFS_I(inode)->i_acl;
	54	break;
	55	case ACL_TYPE_DEFAULT:
95819c05	56	name = POSIX_ACL_XATTR_DEFAULT;
33268eaf JB	57	p_acl = &BTRFS_I(inode)->i_default_acl;
	58	break;
	59	default:
	60	return ERR_PTR(-EINVAL);
	61	}
	62
	63	spin_lock(&inode->i_lock);
	64	if (*p_acl != BTRFS_ACL_NOT_CACHED)
	65	acl = posix_acl_dup(*p_acl);
	66	spin_unlock(&inode->i_lock);
	67
	68	if (acl)
	69	return acl;
	70
	71
95819c05	72	size = __btrfs_getxattr(inode, name, "", 0);
33268eaf JB	73	if (size > 0) {
	74	value = kzalloc(size, GFP_NOFS);
	75	if (!value)
	76	return ERR_PTR(-ENOMEM);
95819c05	77	size = __btrfs_getxattr(inode, name, value, size);
33268eaf JB	78	if (size > 0) {
	79	acl = posix_acl_from_xattr(value, size);
	80	btrfs_update_cached_acl(inode, p_acl, acl);
	81	}
	82	kfree(value);
	83	} else if (size == -ENOENT) {
	84	acl = NULL;
	85	btrfs_update_cached_acl(inode, p_acl, acl);
	86	}
	87
	88	return acl;
	89	}
	90
	91	static int btrfs_xattr_get_acl(struct inode *inode, int type,
	92	void *value, size_t size)
	93	{
	94	struct posix_acl *acl;
	95	int ret = 0;
	96
	97	acl = btrfs_get_acl(inode, type);
	98
	99	if (IS_ERR(acl))
	100	return PTR_ERR(acl);
	101	if (acl == NULL)
	102	return -ENODATA;
	103	ret = posix_acl_to_xattr(acl, value, size);
	104	posix_acl_release(acl);
	105
	106	return ret;
	107	}
	108
	109	/*
	110	* Needs to be called with fs_mutex held
	111	*/
	112	static int btrfs_set_acl(struct inode inode, struct posix_acl acl, int type)
	113	{
95819c05 CH	114	int ret, size = 0;
95819c05 CH	115	const char *name;
33268eaf JB	116	struct posix_acl **p_acl;
	117	char *value = NULL;
	118	mode_t mode;
	119
	120	if (acl) {
	121	ret = posix_acl_valid(acl);
	122	if (ret < 0)
	123	return ret;
	124	ret = 0;
	125	}
	126
	127	switch (type) {
	128	case ACL_TYPE_ACCESS:
	129	mode = inode->i_mode;
	130	ret = posix_acl_equiv_mode(acl, &mode);
	131	if (ret < 0)
	132	return ret;
	133	ret = 0;
	134	inode->i_mode = mode;
95819c05	135	name = POSIX_ACL_XATTR_ACCESS;
33268eaf JB	136	p_acl = &BTRFS_I(inode)->i_acl;
	137	break;
	138	case ACL_TYPE_DEFAULT:
	139	if (!S_ISDIR(inode->i_mode))
	140	return acl ? -EINVAL : 0;
95819c05	141	name = POSIX_ACL_XATTR_DEFAULT;
33268eaf JB	142	p_acl = &BTRFS_I(inode)->i_default_acl;
	143	break;
	144	default:
	145	return -EINVAL;
	146	}
	147
	148	if (acl) {
	149	size = posix_acl_xattr_size(acl->a_count);
	150	value = kmalloc(size, GFP_NOFS);
	151	if (!value) {
	152	ret = -ENOMEM;
	153	goto out;
	154	}
	155
	156	ret = posix_acl_to_xattr(acl, value, size);
	157	if (ret < 0)
	158	goto out;
	159	}
	160
95819c05	161	ret = __btrfs_setxattr(inode, name, value, size, 0);
33268eaf JB	162
	163	out:
	164	if (value)
	165	kfree(value);
	166
	167	if (!ret)
	168	btrfs_update_cached_acl(inode, p_acl, acl);
	169
	170	return ret;
	171	}
fb4bc1e0	172
744f52f9 Y	173	static int btrfs_xattr_set_acl(struct inode *inode, int type,
	174	const void *value, size_t size)
	175	{
	176	int ret = 0;
33268eaf	177	struct posix_acl *acl = NULL;
5103e947	178
744f52f9 Y	179	if (value) {
	180	acl = posix_acl_from_xattr(value, size);
	181	if (acl == NULL) {
	182	value = NULL;
	183	size = 0;
	184	} else if (IS_ERR(acl)) {
33268eaf	185	return PTR_ERR(acl);
744f52f9	186	}
744f52f9	187	}
1caf9342	188
33268eaf JB	189	ret = btrfs_set_acl(inode, acl, type);
	190
	191	posix_acl_release(acl);
	192
	193	return ret;
744f52f9	194	}
33268eaf JB	195
33268eaf JB	196
5103e947 JB	197	static int btrfs_xattr_acl_access_get(struct inode inode, const char name,
	198	void *value, size_t size)
	199	{
33268eaf	200	return btrfs_xattr_get_acl(inode, ACL_TYPE_ACCESS, value, size);
5103e947	201	}
33268eaf	202
5103e947 JB	203	static int btrfs_xattr_acl_access_set(struct inode inode, const char name,
	204	const void *value, size_t size, int flags)
	205	{
33268eaf	206	return btrfs_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
5103e947	207	}
33268eaf	208
5103e947 JB	209	static int btrfs_xattr_acl_default_get(struct inode inode, const char name,
	210	void *value, size_t size)
	211	{
33268eaf	212	return btrfs_xattr_get_acl(inode, ACL_TYPE_DEFAULT, value, size);
5103e947	213	}
33268eaf	214
5103e947 JB	215	static int btrfs_xattr_acl_default_set(struct inode inode, const char name,
	216	const void *value, size_t size, int flags)
	217	{
33268eaf JB	218	return btrfs_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
	219	}
	220
	221	int btrfs_check_acl(struct inode *inode, int mask)
	222	{
	223	struct posix_acl *acl;
	224	int error = -EAGAIN;
	225
	226	acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
	227
	228	if (IS_ERR(acl))
	229	return PTR_ERR(acl);
	230	if (acl) {
	231	error = posix_acl_permission(inode, acl, mask);
	232	posix_acl_release(acl);
	233	}
	234
	235	return error;
	236	}
	237
	238	/*
	239	* btrfs_init_acl is already generally called under fs_mutex, so the locking
	240	* stuff has been fixed to work with that. If the locking stuff changes, we
	241	* need to re-evaluate the acl locking stuff.
	242	*/
	243	int btrfs_init_acl(struct inode inode, struct inode dir)
	244	{
	245	struct posix_acl *acl = NULL;
	246	int ret = 0;
	247
	248	/* this happens with subvols */
	249	if (!dir)
	250	return 0;
	251
	252	if (!S_ISLNK(inode->i_mode)) {
	253	if (IS_POSIXACL(dir)) {
	254	acl = btrfs_get_acl(dir, ACL_TYPE_DEFAULT);
	255	if (IS_ERR(acl))
	256	return PTR_ERR(acl);
	257	}
	258
	259	if (!acl)
	260	inode->i_mode &= ~current->fs->umask;
	261	}
	262
	263	if (IS_POSIXACL(dir) && acl) {
	264	struct posix_acl *clone;
	265	mode_t mode;
	266
	267	if (S_ISDIR(inode->i_mode)) {
	268	ret = btrfs_set_acl(inode, acl, ACL_TYPE_DEFAULT);
	269	if (ret)
	270	goto failed;
	271	}
	272	clone = posix_acl_clone(acl, GFP_NOFS);
	273	ret = -ENOMEM;
	274	if (!clone)
	275	goto failed;
	276
	277	mode = inode->i_mode;
	278	ret = posix_acl_create_masq(clone, &mode);
	279	if (ret >= 0) {
	280	inode->i_mode = mode;
	281	if (ret > 0) {
282	/* we need an acl */
283	ret = btrfs_set_acl(inode, clone,
284	ACL_TYPE_ACCESS);
285	}
286	}
287	}
288	failed:
289	posix_acl_release(acl);
290
291	return ret;
292	}
293
294	int btrfs_acl_chmod(struct inode *inode)
295	{
296	struct posix_acl acl, clone;
297	int ret = 0;
298
299	if (S_ISLNK(inode->i_mode))
300	return -EOPNOTSUPP;
301
302	if (!IS_POSIXACL(inode))
303	return 0;
304
305	acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
306	if (IS_ERR(acl) \|\| !acl)
307	return PTR_ERR(acl);
308
309	clone = posix_acl_clone(acl, GFP_KERNEL);
310	posix_acl_release(acl);
311	if (!clone)
312	return -ENOMEM;
313
314	ret = posix_acl_chmod_masq(clone, inode->i_mode);
315	if (!ret)
316	ret = btrfs_set_acl(inode, clone, ACL_TYPE_ACCESS);
317
318	posix_acl_release(clone);
319
320	return ret;
5103e947	321	}
33268eaf	322
5103e947 JB	323	struct xattr_handler btrfs_xattr_acl_default_handler = {
5103e947 JB	324	.prefix = POSIX_ACL_XATTR_DEFAULT,
5103e947 JB	325	.get = btrfs_xattr_acl_default_get,
	326	.set = btrfs_xattr_acl_default_set,
	327	};
	328
	329	struct xattr_handler btrfs_xattr_acl_access_handler = {
	330	.prefix = POSIX_ACL_XATTR_ACCESS,
5103e947 JB	331	.get = btrfs_xattr_acl_access_get,
	332	.set = btrfs_xattr_acl_access_set,
	333	};
eab922ec JB	334
	335	#else /* CONFIG_FS_POSIX_ACL */
	336
	337	int btrfs_acl_chmod(struct inode *inode)
	338	{
	339	return 0;
	340	}
	341
	342	int btrfs_init_acl(struct inode inode, struct inode dir)
	343	{
	344	return 0;
	345	}
	346
	347	int btrfs_check_acl(struct inode *inode, int mask)
	348	{
	349	return 0;
	350	}
	351
	352	#endif /* CONFIG_FS_POSIX_ACL */