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