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1// SPDX-License-Identifier: GPL-2.0
2#include <linux/fs.h>
3#include <linux/gfp.h>
4#include <linux/nfs.h>
5#include <linux/nfs3.h>
6#include <linux/nfs_fs.h>
7#include <linux/posix_acl_xattr.h>
8#include <linux/nfsacl.h>
9
10#include "internal.h"
11#include "nfs3_fs.h"
12
13#define NFSDBG_FACILITY NFSDBG_PROC
14
15/*
16 * nfs3_prepare_get_acl, nfs3_complete_get_acl, nfs3_abort_get_acl: Helpers for
17 * caching get_acl results in a race-free way. See fs/posix_acl.c:get_acl()
18 * for explanations.
19 */
20static void nfs3_prepare_get_acl(struct posix_acl **p)
21{
22 struct posix_acl *sentinel = uncached_acl_sentinel(current);
23
24 if (cmpxchg(p, ACL_NOT_CACHED, sentinel) != ACL_NOT_CACHED) {
25 /* Not the first reader or sentinel already in place. */
26 }
27}
28
29static void nfs3_complete_get_acl(struct posix_acl **p, struct posix_acl *acl)
30{
31 struct posix_acl *sentinel = uncached_acl_sentinel(current);
32
33 /* Only cache the ACL if our sentinel is still in place. */
34 posix_acl_dup(acl);
35 if (cmpxchg(p, sentinel, acl) != sentinel)
36 posix_acl_release(acl);
37}
38
39static void nfs3_abort_get_acl(struct posix_acl **p)
40{
41 struct posix_acl *sentinel = uncached_acl_sentinel(current);
42
43 /* Remove our sentinel upon failure. */
44 cmpxchg(p, sentinel, ACL_NOT_CACHED);
45}
46
47struct posix_acl *nfs3_get_acl(struct inode *inode, int type)
48{
49 struct nfs_server *server = NFS_SERVER(inode);
50 struct page *pages[NFSACL_MAXPAGES] = { };
51 struct nfs3_getaclargs args = {
52 .fh = NFS_FH(inode),
53 /* The xdr layer may allocate pages here. */
54 .pages = pages,
55 };
56 struct nfs3_getaclres res = {
57 NULL,
58 };
59 struct rpc_message msg = {
60 .rpc_argp = &args,
61 .rpc_resp = &res,
62 };
63 int status, count;
64
65 if (!nfs_server_capable(inode, NFS_CAP_ACLS))
66 return ERR_PTR(-EOPNOTSUPP);
67
68 status = nfs_revalidate_inode(server, inode);
69 if (status < 0)
70 return ERR_PTR(status);
71
72 /*
73 * Only get the access acl when explicitly requested: We don't
74 * need it for access decisions, and only some applications use
75 * it. Applications which request the access acl first are not
76 * penalized from this optimization.
77 */
78 if (type == ACL_TYPE_ACCESS)
79 args.mask |= NFS_ACLCNT|NFS_ACL;
80 if (S_ISDIR(inode->i_mode))
81 args.mask |= NFS_DFACLCNT|NFS_DFACL;
82 if (args.mask == 0)
83 return NULL;
84
85 dprintk("NFS call getacl\n");
86 msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
87 res.fattr = nfs_alloc_fattr();
88 if (res.fattr == NULL)
89 return ERR_PTR(-ENOMEM);
90
91 if (args.mask & NFS_ACL)
92 nfs3_prepare_get_acl(&inode->i_acl);
93 if (args.mask & NFS_DFACL)
94 nfs3_prepare_get_acl(&inode->i_default_acl);
95
96 status = rpc_call_sync(server->client_acl, &msg, 0);
97 dprintk("NFS reply getacl: %d\n", status);
98
99 /* pages may have been allocated at the xdr layer. */
100 for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
101 __free_page(args.pages[count]);
102
103 switch (status) {
104 case 0:
105 status = nfs_refresh_inode(inode, res.fattr);
106 break;
107 case -EPFNOSUPPORT:
108 case -EPROTONOSUPPORT:
109 dprintk("NFS_V3_ACL extension not supported; disabling\n");
110 server->caps &= ~NFS_CAP_ACLS;
111 case -ENOTSUPP:
112 status = -EOPNOTSUPP;
113 default:
114 goto getout;
115 }
116 if ((args.mask & res.mask) != args.mask) {
117 status = -EIO;
118 goto getout;
119 }
120
121 if (res.acl_access != NULL) {
122 if ((posix_acl_equiv_mode(res.acl_access, NULL) == 0) ||
123 res.acl_access->a_count == 0) {
124 posix_acl_release(res.acl_access);
125 res.acl_access = NULL;
126 }
127 }
128
129 if (res.mask & NFS_ACL)
130 nfs3_complete_get_acl(&inode->i_acl, res.acl_access);
131 else
132 forget_cached_acl(inode, ACL_TYPE_ACCESS);
133
134 if (res.mask & NFS_DFACL)
135 nfs3_complete_get_acl(&inode->i_default_acl, res.acl_default);
136 else
137 forget_cached_acl(inode, ACL_TYPE_DEFAULT);
138
139 nfs_free_fattr(res.fattr);
140 if (type == ACL_TYPE_ACCESS) {
141 posix_acl_release(res.acl_default);
142 return res.acl_access;
143 } else {
144 posix_acl_release(res.acl_access);
145 return res.acl_default;
146 }
147
148getout:
149 nfs3_abort_get_acl(&inode->i_acl);
150 nfs3_abort_get_acl(&inode->i_default_acl);
151 posix_acl_release(res.acl_access);
152 posix_acl_release(res.acl_default);
153 nfs_free_fattr(res.fattr);
154 return ERR_PTR(status);
155}
156
157static int __nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
158 struct posix_acl *dfacl)
159{
160 struct nfs_server *server = NFS_SERVER(inode);
161 struct nfs_fattr *fattr;
162 struct page *pages[NFSACL_MAXPAGES];
163 struct nfs3_setaclargs args = {
164 .inode = inode,
165 .mask = NFS_ACL,
166 .acl_access = acl,
167 .pages = pages,
168 };
169 struct rpc_message msg = {
170 .rpc_argp = &args,
171 .rpc_resp = &fattr,
172 };
173 int status = 0;
174
175 if (acl == NULL && (!S_ISDIR(inode->i_mode) || dfacl == NULL))
176 goto out;
177
178 status = -EOPNOTSUPP;
179 if (!nfs_server_capable(inode, NFS_CAP_ACLS))
180 goto out;
181
182 /* We are doing this here because XDR marshalling does not
183 * return any results, it BUGs. */
184 status = -ENOSPC;
185 if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
186 goto out;
187 if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
188 goto out;
189 if (S_ISDIR(inode->i_mode)) {
190 args.mask |= NFS_DFACL;
191 args.acl_default = dfacl;
192 args.len = nfsacl_size(acl, dfacl);
193 } else
194 args.len = nfsacl_size(acl, NULL);
195
196 if (args.len > NFS_ACL_INLINE_BUFSIZE) {
197 unsigned int npages = 1 + ((args.len - 1) >> PAGE_SHIFT);
198
199 status = -ENOMEM;
200 do {
201 args.pages[args.npages] = alloc_page(GFP_KERNEL);
202 if (args.pages[args.npages] == NULL)
203 goto out_freepages;
204 args.npages++;
205 } while (args.npages < npages);
206 }
207
208 dprintk("NFS call setacl\n");
209 status = -ENOMEM;
210 fattr = nfs_alloc_fattr();
211 if (fattr == NULL)
212 goto out_freepages;
213
214 msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
215 msg.rpc_resp = fattr;
216 status = rpc_call_sync(server->client_acl, &msg, 0);
217 nfs_access_zap_cache(inode);
218 nfs_zap_acl_cache(inode);
219 dprintk("NFS reply setacl: %d\n", status);
220
221 switch (status) {
222 case 0:
223 status = nfs_refresh_inode(inode, fattr);
224 set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
225 set_cached_acl(inode, ACL_TYPE_DEFAULT, dfacl);
226 break;
227 case -EPFNOSUPPORT:
228 case -EPROTONOSUPPORT:
229 dprintk("NFS_V3_ACL SETACL RPC not supported"
230 "(will not retry)\n");
231 server->caps &= ~NFS_CAP_ACLS;
232 case -ENOTSUPP:
233 status = -EOPNOTSUPP;
234 }
235 nfs_free_fattr(fattr);
236out_freepages:
237 while (args.npages != 0) {
238 args.npages--;
239 __free_page(args.pages[args.npages]);
240 }
241out:
242 return status;
243}
244
245int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
246 struct posix_acl *dfacl)
247{
248 int ret;
249 ret = __nfs3_proc_setacls(inode, acl, dfacl);
250 return (ret == -EOPNOTSUPP) ? 0 : ret;
251
252}
253
254int nfs3_set_acl(struct inode *inode, struct posix_acl *acl, int type)
255{
256 struct posix_acl *alloc = NULL, *dfacl = NULL;
257 int status;
258
259 if (S_ISDIR(inode->i_mode)) {
260 switch(type) {
261 case ACL_TYPE_ACCESS:
262 alloc = dfacl = get_acl(inode, ACL_TYPE_DEFAULT);
263 if (IS_ERR(alloc))
264 goto fail;
265 break;
266
267 case ACL_TYPE_DEFAULT:
268 dfacl = acl;
269 alloc = acl = get_acl(inode, ACL_TYPE_ACCESS);
270 if (IS_ERR(alloc))
271 goto fail;
272 break;
273 }
274 }
275
276 if (acl == NULL) {
277 alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
278 if (IS_ERR(alloc))
279 goto fail;
280 }
281 status = __nfs3_proc_setacls(inode, acl, dfacl);
282 posix_acl_release(alloc);
283 return status;
284
285fail:
286 return PTR_ERR(alloc);
287}
288
289const struct xattr_handler *nfs3_xattr_handlers[] = {
290 &posix_acl_access_xattr_handler,
291 &posix_acl_default_xattr_handler,
292 NULL,
293};
294
295static int
296nfs3_list_one_acl(struct inode *inode, int type, const char *name, void *data,
297 size_t size, ssize_t *result)
298{
299 struct posix_acl *acl;
300 char *p = data + *result;
301
302 acl = get_acl(inode, type);
303 if (IS_ERR_OR_NULL(acl))
304 return 0;
305
306 posix_acl_release(acl);
307
308 *result += strlen(name);
309 *result += 1;
310 if (!size)
311 return 0;
312 if (*result > size)
313 return -ERANGE;
314
315 strcpy(p, name);
316 return 0;
317}
318
319ssize_t
320nfs3_listxattr(struct dentry *dentry, char *data, size_t size)
321{
322 struct inode *inode = d_inode(dentry);
323 ssize_t result = 0;
324 int error;
325
326 error = nfs3_list_one_acl(inode, ACL_TYPE_ACCESS,
327 XATTR_NAME_POSIX_ACL_ACCESS, data, size, &result);
328 if (error)
329 return error;
330
331 error = nfs3_list_one_acl(inode, ACL_TYPE_DEFAULT,
332 XATTR_NAME_POSIX_ACL_DEFAULT, data, size, &result);
333 if (error)
334 return error;
335 return result;
336}
1// SPDX-License-Identifier: GPL-2.0
2#include <linux/fs.h>
3#include <linux/gfp.h>
4#include <linux/nfs.h>
5#include <linux/nfs3.h>
6#include <linux/nfs_fs.h>
7#include <linux/posix_acl_xattr.h>
8#include <linux/nfsacl.h>
9
10#include "internal.h"
11#include "nfs3_fs.h"
12
13#define NFSDBG_FACILITY NFSDBG_PROC
14
15/*
16 * nfs3_prepare_get_acl, nfs3_complete_get_acl, nfs3_abort_get_acl: Helpers for
17 * caching get_acl results in a race-free way. See fs/posix_acl.c:get_acl()
18 * for explanations.
19 */
20static void nfs3_prepare_get_acl(struct posix_acl **p)
21{
22 struct posix_acl *sentinel = uncached_acl_sentinel(current);
23
24 if (cmpxchg(p, ACL_NOT_CACHED, sentinel) != ACL_NOT_CACHED) {
25 /* Not the first reader or sentinel already in place. */
26 }
27}
28
29static void nfs3_complete_get_acl(struct posix_acl **p, struct posix_acl *acl)
30{
31 struct posix_acl *sentinel = uncached_acl_sentinel(current);
32
33 /* Only cache the ACL if our sentinel is still in place. */
34 posix_acl_dup(acl);
35 if (cmpxchg(p, sentinel, acl) != sentinel)
36 posix_acl_release(acl);
37}
38
39static void nfs3_abort_get_acl(struct posix_acl **p)
40{
41 struct posix_acl *sentinel = uncached_acl_sentinel(current);
42
43 /* Remove our sentinel upon failure. */
44 cmpxchg(p, sentinel, ACL_NOT_CACHED);
45}
46
47struct posix_acl *nfs3_get_acl(struct inode *inode, int type)
48{
49 struct nfs_server *server = NFS_SERVER(inode);
50 struct page *pages[NFSACL_MAXPAGES] = { };
51 struct nfs3_getaclargs args = {
52 .fh = NFS_FH(inode),
53 /* The xdr layer may allocate pages here. */
54 .pages = pages,
55 };
56 struct nfs3_getaclres res = {
57 NULL,
58 };
59 struct rpc_message msg = {
60 .rpc_argp = &args,
61 .rpc_resp = &res,
62 };
63 int status, count;
64
65 if (!nfs_server_capable(inode, NFS_CAP_ACLS))
66 return ERR_PTR(-EOPNOTSUPP);
67
68 status = nfs_revalidate_inode(inode, NFS_INO_INVALID_CHANGE);
69 if (status < 0)
70 return ERR_PTR(status);
71
72 /*
73 * Only get the access acl when explicitly requested: We don't
74 * need it for access decisions, and only some applications use
75 * it. Applications which request the access acl first are not
76 * penalized from this optimization.
77 */
78 if (type == ACL_TYPE_ACCESS)
79 args.mask |= NFS_ACLCNT|NFS_ACL;
80 if (S_ISDIR(inode->i_mode))
81 args.mask |= NFS_DFACLCNT|NFS_DFACL;
82 if (args.mask == 0)
83 return NULL;
84
85 dprintk("NFS call getacl\n");
86 msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
87 res.fattr = nfs_alloc_fattr();
88 if (res.fattr == NULL)
89 return ERR_PTR(-ENOMEM);
90
91 if (args.mask & NFS_ACL)
92 nfs3_prepare_get_acl(&inode->i_acl);
93 if (args.mask & NFS_DFACL)
94 nfs3_prepare_get_acl(&inode->i_default_acl);
95
96 status = rpc_call_sync(server->client_acl, &msg, 0);
97 dprintk("NFS reply getacl: %d\n", status);
98
99 /* pages may have been allocated at the xdr layer. */
100 for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
101 __free_page(args.pages[count]);
102
103 switch (status) {
104 case 0:
105 status = nfs_refresh_inode(inode, res.fattr);
106 break;
107 case -EPFNOSUPPORT:
108 case -EPROTONOSUPPORT:
109 dprintk("NFS_V3_ACL extension not supported; disabling\n");
110 server->caps &= ~NFS_CAP_ACLS;
111 fallthrough;
112 case -ENOTSUPP:
113 status = -EOPNOTSUPP;
114 goto getout;
115 default:
116 goto getout;
117 }
118 if ((args.mask & res.mask) != args.mask) {
119 status = -EIO;
120 goto getout;
121 }
122
123 if (res.acl_access != NULL) {
124 if ((posix_acl_equiv_mode(res.acl_access, NULL) == 0) ||
125 res.acl_access->a_count == 0) {
126 posix_acl_release(res.acl_access);
127 res.acl_access = NULL;
128 }
129 }
130
131 if (res.mask & NFS_ACL)
132 nfs3_complete_get_acl(&inode->i_acl, res.acl_access);
133 else
134 forget_cached_acl(inode, ACL_TYPE_ACCESS);
135
136 if (res.mask & NFS_DFACL)
137 nfs3_complete_get_acl(&inode->i_default_acl, res.acl_default);
138 else
139 forget_cached_acl(inode, ACL_TYPE_DEFAULT);
140
141 nfs_free_fattr(res.fattr);
142 if (type == ACL_TYPE_ACCESS) {
143 posix_acl_release(res.acl_default);
144 return res.acl_access;
145 } else {
146 posix_acl_release(res.acl_access);
147 return res.acl_default;
148 }
149
150getout:
151 nfs3_abort_get_acl(&inode->i_acl);
152 nfs3_abort_get_acl(&inode->i_default_acl);
153 posix_acl_release(res.acl_access);
154 posix_acl_release(res.acl_default);
155 nfs_free_fattr(res.fattr);
156 return ERR_PTR(status);
157}
158
159static int __nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
160 struct posix_acl *dfacl)
161{
162 struct nfs_server *server = NFS_SERVER(inode);
163 struct nfs_fattr *fattr;
164 struct page *pages[NFSACL_MAXPAGES];
165 struct nfs3_setaclargs args = {
166 .inode = inode,
167 .mask = NFS_ACL,
168 .acl_access = acl,
169 .pages = pages,
170 };
171 struct rpc_message msg = {
172 .rpc_argp = &args,
173 .rpc_resp = &fattr,
174 };
175 int status = 0;
176
177 if (acl == NULL && (!S_ISDIR(inode->i_mode) || dfacl == NULL))
178 goto out;
179
180 status = -EOPNOTSUPP;
181 if (!nfs_server_capable(inode, NFS_CAP_ACLS))
182 goto out;
183
184 /* We are doing this here because XDR marshalling does not
185 * return any results, it BUGs. */
186 status = -ENOSPC;
187 if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
188 goto out;
189 if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
190 goto out;
191 if (S_ISDIR(inode->i_mode)) {
192 args.mask |= NFS_DFACL;
193 args.acl_default = dfacl;
194 args.len = nfsacl_size(acl, dfacl);
195 } else
196 args.len = nfsacl_size(acl, NULL);
197
198 if (args.len > NFS_ACL_INLINE_BUFSIZE) {
199 unsigned int npages = 1 + ((args.len - 1) >> PAGE_SHIFT);
200
201 status = -ENOMEM;
202 do {
203 args.pages[args.npages] = alloc_page(GFP_KERNEL);
204 if (args.pages[args.npages] == NULL)
205 goto out_freepages;
206 args.npages++;
207 } while (args.npages < npages);
208 }
209
210 dprintk("NFS call setacl\n");
211 status = -ENOMEM;
212 fattr = nfs_alloc_fattr();
213 if (fattr == NULL)
214 goto out_freepages;
215
216 msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
217 msg.rpc_resp = fattr;
218 status = rpc_call_sync(server->client_acl, &msg, 0);
219 nfs_access_zap_cache(inode);
220 nfs_zap_acl_cache(inode);
221 dprintk("NFS reply setacl: %d\n", status);
222
223 switch (status) {
224 case 0:
225 status = nfs_refresh_inode(inode, fattr);
226 break;
227 case -EPFNOSUPPORT:
228 case -EPROTONOSUPPORT:
229 dprintk("NFS_V3_ACL SETACL RPC not supported"
230 "(will not retry)\n");
231 server->caps &= ~NFS_CAP_ACLS;
232 fallthrough;
233 case -ENOTSUPP:
234 status = -EOPNOTSUPP;
235 }
236 nfs_free_fattr(fattr);
237out_freepages:
238 while (args.npages != 0) {
239 args.npages--;
240 __free_page(args.pages[args.npages]);
241 }
242out:
243 return status;
244}
245
246int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
247 struct posix_acl *dfacl)
248{
249 int ret;
250 ret = __nfs3_proc_setacls(inode, acl, dfacl);
251 return (ret == -EOPNOTSUPP) ? 0 : ret;
252
253}
254
255int nfs3_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
256 struct posix_acl *acl, int type)
257{
258 struct posix_acl *orig = acl, *dfacl = NULL, *alloc;
259 int status;
260
261 if (S_ISDIR(inode->i_mode)) {
262 switch(type) {
263 case ACL_TYPE_ACCESS:
264 alloc = get_acl(inode, ACL_TYPE_DEFAULT);
265 if (IS_ERR(alloc))
266 goto fail;
267 dfacl = alloc;
268 break;
269
270 case ACL_TYPE_DEFAULT:
271 alloc = get_acl(inode, ACL_TYPE_ACCESS);
272 if (IS_ERR(alloc))
273 goto fail;
274 dfacl = acl;
275 acl = alloc;
276 break;
277 }
278 }
279
280 if (acl == NULL) {
281 alloc = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
282 if (IS_ERR(alloc))
283 goto fail;
284 acl = alloc;
285 }
286 status = __nfs3_proc_setacls(inode, acl, dfacl);
287out:
288 if (acl != orig)
289 posix_acl_release(acl);
290 if (dfacl != orig)
291 posix_acl_release(dfacl);
292 return status;
293
294fail:
295 status = PTR_ERR(alloc);
296 goto out;
297}
298
299const struct xattr_handler *nfs3_xattr_handlers[] = {
300 &posix_acl_access_xattr_handler,
301 &posix_acl_default_xattr_handler,
302 NULL,
303};
304
305static int
306nfs3_list_one_acl(struct inode *inode, int type, const char *name, void *data,
307 size_t size, ssize_t *result)
308{
309 struct posix_acl *acl;
310 char *p = data + *result;
311
312 acl = get_acl(inode, type);
313 if (IS_ERR_OR_NULL(acl))
314 return 0;
315
316 posix_acl_release(acl);
317
318 *result += strlen(name);
319 *result += 1;
320 if (!size)
321 return 0;
322 if (*result > size)
323 return -ERANGE;
324
325 strcpy(p, name);
326 return 0;
327}
328
329ssize_t
330nfs3_listxattr(struct dentry *dentry, char *data, size_t size)
331{
332 struct inode *inode = d_inode(dentry);
333 ssize_t result = 0;
334 int error;
335
336 error = nfs3_list_one_acl(inode, ACL_TYPE_ACCESS,
337 XATTR_NAME_POSIX_ACL_ACCESS, data, size, &result);
338 if (error)
339 return error;
340
341 error = nfs3_list_one_acl(inode, ACL_TYPE_DEFAULT,
342 XATTR_NAME_POSIX_ACL_DEFAULT, data, size, &result);
343 if (error)
344 return error;
345 return result;
346}