1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/fs/ceph/acl.c
4 *
5 * Copyright (C) 2013 Guangliang Zhao, <lucienchao@gmail.com>
6 */
7
8 #include <linux/ceph/ceph_debug.h>
9 #include <linux/fs.h>
10 #include <linux/string.h>
11 #include <linux/xattr.h>
12 #include <linux/posix_acl_xattr.h>
13 #include <linux/posix_acl.h>
14 #include <linux/sched.h>
15 #include <linux/slab.h>
16
17 #include "super.h"
18 #include "mds_client.h"
19
20 static inline void ceph_set_cached_acl(struct inode *inode,
21 int type, struct posix_acl *acl)
22 {
23 struct ceph_inode_info *ci = ceph_inode(inode);
24
25 spin_lock(&ci->i_ceph_lock);
26 if (__ceph_caps_issued_mask_metric(ci, CEPH_CAP_XATTR_SHARED, 0))
27 set_cached_acl(inode, type, acl);
28 else
29 forget_cached_acl(inode, type);
30 spin_unlock(&ci->i_ceph_lock);
31 }
32
33 struct posix_acl *ceph_get_acl(struct inode *inode, int type, bool rcu)
34 {
35 struct ceph_client *cl = ceph_inode_to_client(inode);
36 int size;
37 unsigned int retry_cnt = 0;
38 const char *name;
39 char *value = NULL;
40 struct posix_acl *acl;
41
42 if (rcu)
43 return ERR_PTR(-ECHILD);
44
45 switch (type) {
46 case ACL_TYPE_ACCESS:
47 name = XATTR_NAME_POSIX_ACL_ACCESS;
48 break;
49 case ACL_TYPE_DEFAULT:
50 name = XATTR_NAME_POSIX_ACL_DEFAULT;
51 break;
52 default:
53 BUG();
54 }
55
56 retry:
57 size = __ceph_getxattr(inode, name, "", 0);
58 if (size > 0) {
59 value = kzalloc(size, GFP_NOFS);
60 if (!value)
61 return ERR_PTR(-ENOMEM);
62 size = __ceph_getxattr(inode, name, value, size);
63 }
64
65 if (size == -ERANGE && retry_cnt < 10) {
66 retry_cnt++;
67 kfree(value);
68 value = NULL;
69 goto retry;
70 }
71
72 if (size > 0) {
73 acl = posix_acl_from_xattr(&init_user_ns, value, size);
74 } else if (size == -ENODATA || size == 0) {
75 acl = NULL;
76 } else {
77 pr_err_ratelimited_client(cl, "%llx.%llx failed, err=%d\n",
78 ceph_vinop(inode), size);
79 acl = ERR_PTR(-EIO);
80 }
81
82 kfree(value);
83
84 if (!IS_ERR(acl))
85 ceph_set_cached_acl(inode, type, acl);
86
87 return acl;
88 }
89
90 int ceph_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
91 struct posix_acl *acl, int type)
92 {
93 int ret = 0, size = 0;
94 const char *name = NULL;
95 char *value = NULL;
96 struct iattr newattrs;
97 struct inode *inode = d_inode(dentry);
98 struct timespec64 old_ctime = inode_get_ctime(inode);
99 umode_t new_mode = inode->i_mode, old_mode = inode->i_mode;
100
101 if (ceph_snap(inode) != CEPH_NOSNAP) {
102 ret = -EROFS;
103 goto out;
104 }
105
106 switch (type) {
107 case ACL_TYPE_ACCESS:
108 name = XATTR_NAME_POSIX_ACL_ACCESS;
109 if (acl) {
110 ret = posix_acl_update_mode(idmap, inode,
111 &new_mode, &acl);
112 if (ret)
113 goto out;
114 }
115 break;
116 case ACL_TYPE_DEFAULT:
117 if (!S_ISDIR(inode->i_mode)) {
118 ret = acl ? -EINVAL : 0;
119 goto out;
120 }
121 name = XATTR_NAME_POSIX_ACL_DEFAULT;
122 break;
123 default:
124 ret = -EINVAL;
125 goto out;
126 }
127
128 if (acl) {
129 size = posix_acl_xattr_size(acl->a_count);
130 value = kmalloc(size, GFP_NOFS);
131 if (!value) {
132 ret = -ENOMEM;
133 goto out;
134 }
135
136 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
137 if (ret < 0)
138 goto out_free;
139 }
140
141 if (new_mode != old_mode) {
142 newattrs.ia_ctime = current_time(inode);
143 newattrs.ia_mode = new_mode;
144 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
145 ret = __ceph_setattr(idmap, inode, &newattrs, NULL);
146 if (ret)
147 goto out_free;
148 }
149
150 ret = __ceph_setxattr(inode, name, value, size, 0);
151 if (ret) {
152 if (new_mode != old_mode) {
153 newattrs.ia_ctime = old_ctime;
154 newattrs.ia_mode = old_mode;
155 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
156 __ceph_setattr(idmap, inode, &newattrs, NULL);
157 }
158 goto out_free;
159 }
160
161 ceph_set_cached_acl(inode, type, acl);
162
163 out_free:
164 kfree(value);
165 out:
166 return ret;
167 }
168
169 int ceph_pre_init_acls(struct inode *dir, umode_t *mode,
170 struct ceph_acl_sec_ctx *as_ctx)
171 {
172 struct posix_acl *acl, *default_acl;
173 size_t val_size1 = 0, val_size2 = 0;
174 struct ceph_pagelist *pagelist = NULL;
175 void *tmp_buf = NULL;
176 int err;
177
178 err = posix_acl_create(dir, mode, &default_acl, &acl);
179 if (err)
180 return err;
181
182 if (acl) {
183 err = posix_acl_equiv_mode(acl, mode);
184 if (err < 0)
185 goto out_err;
186 if (err == 0) {
187 posix_acl_release(acl);
188 acl = NULL;
189 }
190 }
191
192 if (!default_acl && !acl)
193 return 0;
194
195 if (acl)
196 val_size1 = posix_acl_xattr_size(acl->a_count);
197 if (default_acl)
198 val_size2 = posix_acl_xattr_size(default_acl->a_count);
199
200 err = -ENOMEM;
201 tmp_buf = kmalloc(max(val_size1, val_size2), GFP_KERNEL);
202 if (!tmp_buf)
203 goto out_err;
204 pagelist = ceph_pagelist_alloc(GFP_KERNEL);
205 if (!pagelist)
206 goto out_err;
207
208 err = ceph_pagelist_reserve(pagelist, PAGE_SIZE);
209 if (err)
210 goto out_err;
211
212 ceph_pagelist_encode_32(pagelist, acl && default_acl ? 2 : 1);
213
214 if (acl) {
215 size_t len = strlen(XATTR_NAME_POSIX_ACL_ACCESS);
216 err = ceph_pagelist_reserve(pagelist, len + val_size1 + 8);
217 if (err)
218 goto out_err;
219 ceph_pagelist_encode_string(pagelist, XATTR_NAME_POSIX_ACL_ACCESS,
220 len);
221 err = posix_acl_to_xattr(&init_user_ns, acl,
222 tmp_buf, val_size1);
223 if (err < 0)
224 goto out_err;
225 ceph_pagelist_encode_32(pagelist, val_size1);
226 ceph_pagelist_append(pagelist, tmp_buf, val_size1);
227 }
228 if (default_acl) {
229 size_t len = strlen(XATTR_NAME_POSIX_ACL_DEFAULT);
230 err = ceph_pagelist_reserve(pagelist, len + val_size2 + 8);
231 if (err)
232 goto out_err;
233 ceph_pagelist_encode_string(pagelist,
234 XATTR_NAME_POSIX_ACL_DEFAULT, len);
235 err = posix_acl_to_xattr(&init_user_ns, default_acl,
236 tmp_buf, val_size2);
237 if (err < 0)
238 goto out_err;
239 ceph_pagelist_encode_32(pagelist, val_size2);
240 ceph_pagelist_append(pagelist, tmp_buf, val_size2);
241 }
242
243 kfree(tmp_buf);
244
245 as_ctx->acl = acl;
246 as_ctx->default_acl = default_acl;
247 as_ctx->pagelist = pagelist;
248 return 0;
249
250 out_err:
251 posix_acl_release(acl);
252 posix_acl_release(default_acl);
253 kfree(tmp_buf);
254 if (pagelist)
255 ceph_pagelist_release(pagelist);
256 return err;
257 }
258
259 void ceph_init_inode_acls(struct inode *inode, struct ceph_acl_sec_ctx *as_ctx)
260 {
261 if (!inode)
262 return;
263 ceph_set_cached_acl(inode, ACL_TYPE_ACCESS, as_ctx->acl);
264 ceph_set_cached_acl(inode, ACL_TYPE_DEFAULT, as_ctx->default_acl);
265 }
266
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