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