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[hh.org.git] / fs / gfs2 / acl.c
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1 /*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
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 */
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>
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"
31 #define ACL_ACCESS 1
32 #define ACL_DEFAULT 0
34 int gfs2_acl_validate_set(struct gfs2_inode *ip, int access,
35 struct gfs2_ea_request *er,
36 int *remove, mode_t *mode)
38 struct posix_acl *acl;
39 int error;
41 error = gfs2_acl_validate_remove(ip, access);
42 if (error)
43 return error;
45 if (!er->er_data)
46 return -EINVAL;
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;
56 error = posix_acl_valid(acl);
57 if (error)
58 goto out;
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;
68 out:
69 posix_acl_release(acl);
70 return error;
73 int gfs2_acl_validate_remove(struct gfs2_inode *ip, int access)
75 if (!GFS2_SB(&ip->i_inode)->sd_args.ar_posix_acl)
76 return -EOPNOTSUPP;
77 if (current->fsuid != ip->i_di.di_uid && !capable(CAP_FOWNER))
78 return -EPERM;
79 if (S_ISLNK(ip->i_di.di_mode))
80 return -EOPNOTSUPP;
81 if (!access && !S_ISDIR(ip->i_di.di_mode))
82 return -EACCES;
84 return 0;
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)
90 struct gfs2_ea_request er;
91 struct gfs2_ea_location el_this;
92 int error;
94 if (!ip->i_di.di_eattr)
95 return 0;
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;
105 er.er_type = GFS2_EATYPE_SYS;
107 if (!el)
108 el = &el_this;
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;
118 er.er_data_len = GFS2_EA_DATA_LEN(el->el_ea);
119 er.er_data = kmalloc(er.er_data_len, GFP_KERNEL);
120 error = -ENOMEM;
121 if (!er.er_data)
122 goto out;
124 error = gfs2_ea_get_copy(ip, el, er.er_data);
125 if (error)
126 goto out_kfree;
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);
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;
141 out:
142 if (error || el == &el_this)
143 brelse(el->el_bh);
144 return error;
148 * gfs2_check_acl_locked - 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
152 * Returns: errno
155 int gfs2_check_acl_locked(struct inode *inode, int mask)
157 struct posix_acl *acl = NULL;
158 int error;
160 error = acl_get(GFS2_I(inode), ACL_ACCESS, &acl, NULL, NULL, NULL);
161 if (error)
162 return error;
164 if (acl) {
165 error = posix_acl_permission(inode, acl, mask);
166 posix_acl_release(acl);
167 return error;
170 return -EAGAIN;
173 int gfs2_check_acl(struct inode *inode, int mask)
175 struct gfs2_inode *ip = GFS2_I(inode);
176 struct gfs2_holder i_gh;
177 int error;
179 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
180 if (!error) {
181 error = gfs2_check_acl_locked(inode, mask);
182 gfs2_glock_dq_uninit(&i_gh);
185 return error;
188 static int munge_mode(struct gfs2_inode *ip, mode_t mode)
190 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
191 struct buffer_head *dibh;
192 int error;
194 error = gfs2_trans_begin(sdp, RES_DINODE, 0);
195 if (error)
196 return error;
198 error = gfs2_meta_inode_buffer(ip, &dibh);
199 if (!error) {
200 gfs2_assert_withdraw(sdp,
201 (ip->i_di.di_mode & S_IFMT) == (mode & S_IFMT));
202 ip->i_di.di_mode = mode;
203 gfs2_trans_add_bh(ip->i_gl, dibh, 1);
204 gfs2_dinode_out(&ip->i_di, dibh->b_data);
205 brelse(dibh);
208 gfs2_trans_end(sdp);
210 return 0;
213 int gfs2_acl_create(struct gfs2_inode *dip, struct gfs2_inode *ip)
215 struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
216 struct posix_acl *acl = NULL, *clone;
217 struct gfs2_ea_request er;
218 mode_t mode = ip->i_di.di_mode;
219 int error;
221 if (!sdp->sd_args.ar_posix_acl)
222 return 0;
223 if (S_ISLNK(ip->i_di.di_mode))
224 return 0;
226 memset(&er, 0, sizeof(struct gfs2_ea_request));
227 er.er_type = GFS2_EATYPE_SYS;
229 error = acl_get(dip, ACL_DEFAULT, &acl, NULL,
230 &er.er_data, &er.er_data_len);
231 if (error)
232 return error;
233 if (!acl) {
234 mode &= ~current->fs->umask;
235 if (mode != ip->i_di.di_mode)
236 error = munge_mode(ip, mode);
237 return error;
240 clone = posix_acl_clone(acl, GFP_KERNEL);
241 error = -ENOMEM;
242 if (!clone)
243 goto out;
244 posix_acl_release(acl);
245 acl = clone;
247 if (S_ISDIR(ip->i_di.di_mode)) {
248 er.er_name = GFS2_POSIX_ACL_DEFAULT;
249 er.er_name_len = GFS2_POSIX_ACL_DEFAULT_LEN;
250 error = gfs2_system_eaops.eo_set(ip, &er);
251 if (error)
252 goto out;
255 error = posix_acl_create_masq(acl, &mode);
256 if (error < 0)
257 goto out;
258 if (error > 0) {
259 er.er_name = GFS2_POSIX_ACL_ACCESS;
260 er.er_name_len = GFS2_POSIX_ACL_ACCESS_LEN;
261 posix_acl_to_xattr(acl, er.er_data, er.er_data_len);
262 er.er_mode = mode;
263 er.er_flags = GFS2_ERF_MODE;
264 error = gfs2_system_eaops.eo_set(ip, &er);
265 if (error)
266 goto out;
267 } else
268 munge_mode(ip, mode);
270 out:
271 posix_acl_release(acl);
272 kfree(er.er_data);
273 return error;
276 int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr)
278 struct posix_acl *acl = NULL, *clone;
279 struct gfs2_ea_location el;
280 char *data;
281 unsigned int len;
282 int error;
284 error = acl_get(ip, ACL_ACCESS, &acl, &el, &data, &len);
285 if (error)
286 return error;
287 if (!acl)
288 return gfs2_setattr_simple(ip, attr);
290 clone = posix_acl_clone(acl, GFP_KERNEL);
291 error = -ENOMEM;
292 if (!clone)
293 goto out;
294 posix_acl_release(acl);
295 acl = clone;
297 error = posix_acl_chmod_masq(acl, attr->ia_mode);
298 if (!error) {
299 posix_acl_to_xattr(acl, data, len);
300 error = gfs2_ea_acl_chmod(ip, &el, attr, data);
303 out:
304 posix_acl_release(acl);
305 brelse(el.el_bh);
306 kfree(data);
307 return error;