acl.c 6.3 KB
Newer Older
J
Josef Bacik 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
/*
 * 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>
J
Josef Bacik 已提交
23
#include <linux/posix_acl.h>
24
#include <linux/sched.h>
J
Josef Bacik 已提交
25

J
Josef Bacik 已提交
26
#include "ctree.h"
J
Josef Bacik 已提交
27
#include "btrfs_inode.h"
J
Josef Bacik 已提交
28
#include "xattr.h"
J
Josef Bacik 已提交
29

C
Chris Mason 已提交
30
#ifdef CONFIG_BTRFS_FS_POSIX_ACL
31

J
Josef Bacik 已提交
32 33
static struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
{
34 35
	int size;
	const char *name;
J
Josef Bacik 已提交
36
	char *value = NULL;
37 38 39 40 41
	struct posix_acl *acl;

	acl = get_cached_acl(inode, type);
	if (acl != ACL_NOT_CACHED)
		return acl;
J
Josef Bacik 已提交
42 43 44

	switch (type) {
	case ACL_TYPE_ACCESS:
45
		name = POSIX_ACL_XATTR_ACCESS;
J
Josef Bacik 已提交
46 47
		break;
	case ACL_TYPE_DEFAULT:
48
		name = POSIX_ACL_XATTR_DEFAULT;
J
Josef Bacik 已提交
49 50
		break;
	default:
51
		BUG();
J
Josef Bacik 已提交
52 53
	}

54
	size = __btrfs_getxattr(inode, name, "", 0);
J
Josef Bacik 已提交
55 56 57 58
	if (size > 0) {
		value = kzalloc(size, GFP_NOFS);
		if (!value)
			return ERR_PTR(-ENOMEM);
59
		size = __btrfs_getxattr(inode, name, value, size);
J
Josef Bacik 已提交
60 61
		if (size > 0) {
			acl = posix_acl_from_xattr(value, size);
62
			set_cached_acl(inode, type, acl);
J
Josef Bacik 已提交
63 64
		}
		kfree(value);
C
Chris Mason 已提交
65 66
	} else if (size == -ENOENT || size == -ENODATA || size == 0) {
		/* FIXME, who returns -ENOENT?  I think nobody */
J
Josef Bacik 已提交
67
		acl = NULL;
68
		set_cached_acl(inode, type, acl);
C
Chris Mason 已提交
69 70
	} else {
		acl = ERR_PTR(-EIO);
J
Josef Bacik 已提交
71 72 73 74 75
	}

	return acl;
}

76 77
static int btrfs_xattr_acl_get(struct dentry *dentry, const char *name,
		void *value, size_t size, int type)
J
Josef Bacik 已提交
78 79 80 81
{
	struct posix_acl *acl;
	int ret = 0;

82
	acl = btrfs_get_acl(dentry->d_inode, type);
J
Josef Bacik 已提交
83 84 85 86 87 88 89 90 91 92 93 94 95 96

	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
 */
97 98
static int btrfs_set_acl(struct btrfs_trans_handle *trans,
			 struct inode *inode, struct posix_acl *acl, int type)
J
Josef Bacik 已提交
99
{
100 101
	int ret, size = 0;
	const char *name;
J
Josef Bacik 已提交
102 103 104 105 106 107 108 109 110 111 112 113 114
	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;
115
		name = POSIX_ACL_XATTR_ACCESS;
116 117 118 119 120 121 122
		if (acl) {
			ret = posix_acl_equiv_mode(acl, &mode);
			if (ret < 0)
				return ret;
			inode->i_mode = mode;
		}
		ret = 0;
J
Josef Bacik 已提交
123 124 125 126
		break;
	case ACL_TYPE_DEFAULT:
		if (!S_ISDIR(inode->i_mode))
			return acl ? -EINVAL : 0;
127
		name = POSIX_ACL_XATTR_DEFAULT;
J
Josef Bacik 已提交
128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145
		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;
	}

146
	ret = __btrfs_setxattr(trans, inode, name, value, size, 0);
J
Josef Bacik 已提交
147
out:
C
Chris Mason 已提交
148
	kfree(value);
J
Josef Bacik 已提交
149 150

	if (!ret)
151
		set_cached_acl(inode, type, acl);
J
Josef Bacik 已提交
152 153 154

	return ret;
}
Y
Yan 已提交
155

156 157
static int btrfs_xattr_acl_set(struct dentry *dentry, const char *name,
		const void *value, size_t size, int flags, int type)
Y
Yan 已提交
158
{
159
	int ret;
J
Josef Bacik 已提交
160
	struct posix_acl *acl = NULL;
J
Josef Bacik 已提交
161

Y
Yan 已提交
162 163 164 165 166 167
	if (value) {
		acl = posix_acl_from_xattr(value, size);
		if (acl == NULL) {
			value = NULL;
			size = 0;
		} else if (IS_ERR(acl)) {
J
Josef Bacik 已提交
168
			return PTR_ERR(acl);
Y
Yan 已提交
169 170
		}
	}
171

172
	ret = btrfs_set_acl(NULL, dentry->d_inode, acl, type);
J
Josef Bacik 已提交
173 174 175 176

	posix_acl_release(acl);

	return ret;
Y
Yan 已提交
177
}
J
Josef Bacik 已提交
178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200

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.
 */
201 202
int btrfs_init_acl(struct btrfs_trans_handle *trans,
		   struct inode *inode, struct inode *dir)
J
Josef Bacik 已提交
203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218
{
	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)
A
Al Viro 已提交
219
			inode->i_mode &= ~current_umask();
J
Josef Bacik 已提交
220 221 222 223 224 225 226
	}

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

		if (S_ISDIR(inode->i_mode)) {
227 228
			ret = btrfs_set_acl(trans, inode, acl,
					    ACL_TYPE_DEFAULT);
J
Josef Bacik 已提交
229 230 231 232 233 234 235 236 237 238 239 240 241 242
			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 */
243
				ret = btrfs_set_acl(trans, inode, clone,
J
Josef Bacik 已提交
244 245 246
						    ACL_TYPE_ACCESS);
			}
		}
247
		posix_acl_release(clone);
J
Josef Bacik 已提交
248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276
	}
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)
277
		ret = btrfs_set_acl(NULL, inode, clone, ACL_TYPE_ACCESS);
J
Josef Bacik 已提交
278 279 280 281

	posix_acl_release(clone);

	return ret;
J
Josef Bacik 已提交
282
}
J
Josef Bacik 已提交
283

J
Josef Bacik 已提交
284 285
struct xattr_handler btrfs_xattr_acl_default_handler = {
	.prefix = POSIX_ACL_XATTR_DEFAULT,
286 287 288
	.flags	= ACL_TYPE_DEFAULT,
	.get	= btrfs_xattr_acl_get,
	.set	= btrfs_xattr_acl_set,
J
Josef Bacik 已提交
289 290 291 292
};

struct xattr_handler btrfs_xattr_acl_access_handler = {
	.prefix = POSIX_ACL_XATTR_ACCESS,
293 294 295
	.flags	= ACL_TYPE_ACCESS,
	.get	= btrfs_xattr_acl_get,
	.set	= btrfs_xattr_acl_set,
J
Josef Bacik 已提交
296
};
297

C
Chris Mason 已提交
298
#else /* CONFIG_BTRFS_FS_POSIX_ACL */
299 300 301 302 303 304

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

305 306
int btrfs_init_acl(struct btrfs_trans_handle *trans,
		   struct inode *inode, struct inode *dir)
307 308 309 310
{
	return 0;
}

C
Chris Mason 已提交
311
#endif /* CONFIG_BTRFS_FS_POSIX_ACL */