1 /*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
4 *
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License version 2.
8 */
9
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13 #include <linux/completion.h>
14 #include <linux/buffer_head.h>
15 #include <linux/posix_acl.h>
16 #include <linux/posix_acl_xattr.h>
17 #include <linux/gfs2_ondisk.h>
18 #include <linux/lm_interface.h>
19
20 #include "gfs2.h"
21 #include "incore.h"
22 #include "acl.h"
23 #include "eaops.h"
24 #include "eattr.h"
25 #include "glock.h"
26 #include "inode.h"
27 #include "meta_io.h"
28 #include "trans.h"
29 #include "util.h"
30
31 #define ACL_ACCESS 1
32 #define ACL_DEFAULT 0
33
gfs2_acl_validate_set(struct gfs2_inode * ip,int access,struct gfs2_ea_request * er,int * remove,mode_t * mode)34 int gfs2_acl_validate_set(struct gfs2_inode *ip, int access,
35 struct gfs2_ea_request *er,
36 int *remove, mode_t *mode)
37 {
38 struct posix_acl *acl;
39 int error;
40
41 error = gfs2_acl_validate_remove(ip, access);
42 if (error)
43 return error;
44
45 if (!er->er_data)
46 return -EINVAL;
47
48 acl = posix_acl_from_xattr(er->er_data, er->er_data_len);
49 if (IS_ERR(acl))
50 return PTR_ERR(acl);
51 if (!acl) {
52 *remove = 1;
53 return 0;
54 }
55
56 error = posix_acl_valid(acl);
57 if (error)
58 goto out;
59
60 if (access) {
61 error = posix_acl_equiv_mode(acl, mode);
62 if (!error)
63 *remove = 1;
64 else if (error > 0)
65 error = 0;
66 }
67
68 out:
69 posix_acl_release(acl);
70 return error;
71 }
72
gfs2_acl_validate_remove(struct gfs2_inode * ip,int access)73 int gfs2_acl_validate_remove(struct gfs2_inode *ip, int access)
74 {
75 if (!GFS2_SB(&ip->i_inode)->sd_args.ar_posix_acl)
76 return -EOPNOTSUPP;
77 if (!is_owner_or_cap(&ip->i_inode))
78 return -EPERM;
79 if (S_ISLNK(ip->i_inode.i_mode))
80 return -EOPNOTSUPP;
81 if (!access && !S_ISDIR(ip->i_inode.i_mode))
82 return -EACCES;
83
84 return 0;
85 }
86
acl_get(struct gfs2_inode * ip,int access,struct posix_acl ** acl,struct gfs2_ea_location * el,char ** data,unsigned int * len)87 static int acl_get(struct gfs2_inode *ip, int access, struct posix_acl **acl,
88 struct gfs2_ea_location *el, char **data, unsigned int *len)
89 {
90 struct gfs2_ea_request er;
91 struct gfs2_ea_location el_this;
92 int error;
93
94 if (!ip->i_eattr)
95 return 0;
96
97 memset(&er, 0, sizeof(struct gfs2_ea_request));
98 if (access) {
99 er.er_name = GFS2_POSIX_ACL_ACCESS;
100 er.er_name_len = GFS2_POSIX_ACL_ACCESS_LEN;
101 } else {
102 er.er_name = GFS2_POSIX_ACL_DEFAULT;
103 er.er_name_len = GFS2_POSIX_ACL_DEFAULT_LEN;
104 }
105 er.er_type = GFS2_EATYPE_SYS;
106
107 if (!el)
108 el = &el_this;
109
110 error = gfs2_ea_find(ip, &er, el);
111 if (error)
112 return error;
113 if (!el->el_ea)
114 return 0;
115 if (!GFS2_EA_DATA_LEN(el->el_ea))
116 goto out;
117
118 er.er_data_len = GFS2_EA_DATA_LEN(el->el_ea);
119 er.er_data = kmalloc(er.er_data_len, GFP_NOFS);
120 error = -ENOMEM;
121 if (!er.er_data)
122 goto out;
123
124 error = gfs2_ea_get_copy(ip, el, er.er_data);
125 if (error)
126 goto out_kfree;
127
128 if (acl) {
129 *acl = posix_acl_from_xattr(er.er_data, er.er_data_len);
130 if (IS_ERR(*acl))
131 error = PTR_ERR(*acl);
132 }
133
134 out_kfree:
135 if (error || !data)
136 kfree(er.er_data);
137 else {
138 *data = er.er_data;
139 *len = er.er_data_len;
140 }
141 out:
142 if (error || el == &el_this)
143 brelse(el->el_bh);
144 return error;
145 }
146
147 /**
148 * gfs2_check_acl - Check an ACL to see if we're allowed to do something
149 * @inode: the file we want to do something to
150 * @mask: what we want to do
151 *
152 * Returns: errno
153 */
154
gfs2_check_acl(struct inode * inode,int mask)155 int gfs2_check_acl(struct inode *inode, int mask)
156 {
157 struct posix_acl *acl = NULL;
158 int error;
159
160 error = acl_get(GFS2_I(inode), ACL_ACCESS, &acl, NULL, NULL, NULL);
161 if (error)
162 return error;
163
164 if (acl) {
165 error = posix_acl_permission(inode, acl, mask);
166 posix_acl_release(acl);
167 return error;
168 }
169
170 return -EAGAIN;
171 }
172
munge_mode(struct gfs2_inode * ip,mode_t mode)173 static int munge_mode(struct gfs2_inode *ip, mode_t mode)
174 {
175 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
176 struct buffer_head *dibh;
177 int error;
178
179 error = gfs2_trans_begin(sdp, RES_DINODE, 0);
180 if (error)
181 return error;
182
183 error = gfs2_meta_inode_buffer(ip, &dibh);
184 if (!error) {
185 gfs2_assert_withdraw(sdp,
186 (ip->i_inode.i_mode & S_IFMT) == (mode & S_IFMT));
187 ip->i_inode.i_mode = mode;
188 gfs2_trans_add_bh(ip->i_gl, dibh, 1);
189 gfs2_dinode_out(ip, dibh->b_data);
190 brelse(dibh);
191 }
192
193 gfs2_trans_end(sdp);
194
195 return 0;
196 }
197
gfs2_acl_create(struct gfs2_inode * dip,struct gfs2_inode * ip)198 int gfs2_acl_create(struct gfs2_inode *dip, struct gfs2_inode *ip)
199 {
200 struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
201 struct posix_acl *acl = NULL, *clone;
202 struct gfs2_ea_request er;
203 mode_t mode = ip->i_inode.i_mode;
204 int error;
205
206 if (!sdp->sd_args.ar_posix_acl)
207 return 0;
208 if (S_ISLNK(ip->i_inode.i_mode))
209 return 0;
210
211 memset(&er, 0, sizeof(struct gfs2_ea_request));
212 er.er_type = GFS2_EATYPE_SYS;
213
214 error = acl_get(dip, ACL_DEFAULT, &acl, NULL,
215 &er.er_data, &er.er_data_len);
216 if (error)
217 return error;
218 if (!acl) {
219 mode &= ~current->fs->umask;
220 if (mode != ip->i_inode.i_mode)
221 error = munge_mode(ip, mode);
222 return error;
223 }
224
225 clone = posix_acl_clone(acl, GFP_NOFS);
226 error = -ENOMEM;
227 if (!clone)
228 goto out;
229 posix_acl_release(acl);
230 acl = clone;
231
232 if (S_ISDIR(ip->i_inode.i_mode)) {
233 er.er_name = GFS2_POSIX_ACL_DEFAULT;
234 er.er_name_len = GFS2_POSIX_ACL_DEFAULT_LEN;
235 error = gfs2_system_eaops.eo_set(ip, &er);
236 if (error)
237 goto out;
238 }
239
240 error = posix_acl_create_masq(acl, &mode);
241 if (error < 0)
242 goto out;
243 if (error > 0) {
244 er.er_name = GFS2_POSIX_ACL_ACCESS;
245 er.er_name_len = GFS2_POSIX_ACL_ACCESS_LEN;
246 posix_acl_to_xattr(acl, er.er_data, er.er_data_len);
247 er.er_mode = mode;
248 er.er_flags = GFS2_ERF_MODE;
249 error = gfs2_system_eaops.eo_set(ip, &er);
250 if (error)
251 goto out;
252 } else
253 munge_mode(ip, mode);
254
255 out:
256 posix_acl_release(acl);
257 kfree(er.er_data);
258 return error;
259 }
260
gfs2_acl_chmod(struct gfs2_inode * ip,struct iattr * attr)261 int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr)
262 {
263 struct posix_acl *acl = NULL, *clone;
264 struct gfs2_ea_location el;
265 char *data;
266 unsigned int len;
267 int error;
268
269 error = acl_get(ip, ACL_ACCESS, &acl, &el, &data, &len);
270 if (error)
271 return error;
272 if (!acl)
273 return gfs2_setattr_simple(ip, attr);
274
275 clone = posix_acl_clone(acl, GFP_NOFS);
276 error = -ENOMEM;
277 if (!clone)
278 goto out;
279 posix_acl_release(acl);
280 acl = clone;
281
282 error = posix_acl_chmod_masq(acl, attr->ia_mode);
283 if (!error) {
284 posix_acl_to_xattr(acl, data, len);
285 error = gfs2_ea_acl_chmod(ip, &el, attr, data);
286 }
287
288 out:
289 posix_acl_release(acl);
290 brelse(el.el_bh);
291 kfree(data);
292 return error;
293 }
294
295