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(lock: &ci->i_ceph_lock); |
26 | if (__ceph_caps_issued_mask_metric(ci, CEPH_CAP_XATTR_SHARED, t: 0)) |
27 | set_cached_acl(inode, type, acl); |
28 | else |
29 | forget_cached_acl(inode, type); |
30 | spin_unlock(lock: &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(error: -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(error: -ENOMEM); |
62 | size = __ceph_getxattr(inode, name, value, size); |
63 | } |
64 | |
65 | if (size == -ERANGE && retry_cnt < 10) { |
66 | retry_cnt++; |
67 | kfree(objp: value); |
68 | value = NULL; |
69 | goto retry; |
70 | } |
71 | |
72 | if (size > 0) { |
73 | acl = posix_acl_from_xattr(user_ns: &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(error: -EIO); |
80 | } |
81 | |
82 | kfree(objp: value); |
83 | |
84 | if (!IS_ERR(ptr: 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(count: 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(user_ns: &init_user_ns, acl, buffer: 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, attr: &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, attr: &newattrs, NULL); |
157 | } |
158 | goto out_free; |
159 | } |
160 | |
161 | ceph_set_cached_acl(inode, type, acl); |
162 | |
163 | out_free: |
164 | kfree(objp: 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(count: acl->a_count); |
197 | if (default_acl) |
198 | val_size2 = posix_acl_xattr_size(count: 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(pl: pagelist, PAGE_SIZE); |
209 | if (err) |
210 | goto out_err; |
211 | |
212 | ceph_pagelist_encode_32(pl: pagelist, v: acl && default_acl ? 2 : 1); |
213 | |
214 | if (acl) { |
215 | size_t len = strlen(XATTR_NAME_POSIX_ACL_ACCESS); |
216 | err = ceph_pagelist_reserve(pl: pagelist, space: len + val_size1 + 8); |
217 | if (err) |
218 | goto out_err; |
219 | ceph_pagelist_encode_string(pl: pagelist, XATTR_NAME_POSIX_ACL_ACCESS, |
220 | len); |
221 | err = posix_acl_to_xattr(user_ns: &init_user_ns, acl, |
222 | buffer: tmp_buf, size: val_size1); |
223 | if (err < 0) |
224 | goto out_err; |
225 | ceph_pagelist_encode_32(pl: pagelist, v: val_size1); |
226 | ceph_pagelist_append(pl: pagelist, d: tmp_buf, l: val_size1); |
227 | } |
228 | if (default_acl) { |
229 | size_t len = strlen(XATTR_NAME_POSIX_ACL_DEFAULT); |
230 | err = ceph_pagelist_reserve(pl: pagelist, space: len + val_size2 + 8); |
231 | if (err) |
232 | goto out_err; |
233 | ceph_pagelist_encode_string(pl: pagelist, |
234 | XATTR_NAME_POSIX_ACL_DEFAULT, len); |
235 | err = posix_acl_to_xattr(user_ns: &init_user_ns, acl: default_acl, |
236 | buffer: tmp_buf, size: val_size2); |
237 | if (err < 0) |
238 | goto out_err; |
239 | ceph_pagelist_encode_32(pl: pagelist, v: val_size2); |
240 | ceph_pagelist_append(pl: pagelist, d: tmp_buf, l: val_size2); |
241 | } |
242 | |
243 | kfree(objp: 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(acl: default_acl); |
253 | kfree(objp: tmp_buf); |
254 | if (pagelist) |
255 | ceph_pagelist_release(pl: 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, acl: as_ctx->acl); |
264 | ceph_set_cached_acl(inode, ACL_TYPE_DEFAULT, acl: as_ctx->default_acl); |
265 | } |
266 | |