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