xref: /linux/fs/nfs/nfs3acl.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
1 #include <linux/fs.h>
2 #include <linux/nfs.h>
3 #include <linux/nfs3.h>
4 #include <linux/nfs_fs.h>
5 #include <linux/posix_acl_xattr.h>
6 #include <linux/nfsacl.h>
7 
8 #define NFSDBG_FACILITY	NFSDBG_PROC
9 
10 ssize_t nfs3_listxattr(struct dentry *dentry, char *buffer, size_t size)
11 {
12 	struct inode *inode = dentry->d_inode;
13 	struct posix_acl *acl;
14 	int pos=0, len=0;
15 
16 #	define output(s) do {						\
17 			if (pos + sizeof(s) <= size) {			\
18 				memcpy(buffer + pos, s, sizeof(s));	\
19 				pos += sizeof(s);			\
20 			}						\
21 			len += sizeof(s);				\
22 		} while(0)
23 
24 	acl = nfs3_proc_getacl(inode, ACL_TYPE_ACCESS);
25 	if (IS_ERR(acl))
26 		return PTR_ERR(acl);
27 	if (acl) {
28 		output("system.posix_acl_access");
29 		posix_acl_release(acl);
30 	}
31 
32 	if (S_ISDIR(inode->i_mode)) {
33 		acl = nfs3_proc_getacl(inode, ACL_TYPE_DEFAULT);
34 		if (IS_ERR(acl))
35 			return PTR_ERR(acl);
36 		if (acl) {
37 			output("system.posix_acl_default");
38 			posix_acl_release(acl);
39 		}
40 	}
41 
42 #	undef output
43 
44 	if (!buffer || len <= size)
45 		return len;
46 	return -ERANGE;
47 }
48 
49 ssize_t nfs3_getxattr(struct dentry *dentry, const char *name,
50 		void *buffer, size_t size)
51 {
52 	struct inode *inode = dentry->d_inode;
53 	struct posix_acl *acl;
54 	int type, error = 0;
55 
56 	if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
57 		type = ACL_TYPE_ACCESS;
58 	else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
59 		type = ACL_TYPE_DEFAULT;
60 	else
61 		return -EOPNOTSUPP;
62 
63 	acl = nfs3_proc_getacl(inode, type);
64 	if (IS_ERR(acl))
65 		return PTR_ERR(acl);
66 	else if (acl) {
67 		if (type == ACL_TYPE_ACCESS && acl->a_count == 0)
68 			error = -ENODATA;
69 		else
70 			error = posix_acl_to_xattr(acl, buffer, size);
71 		posix_acl_release(acl);
72 	} else
73 		error = -ENODATA;
74 
75 	return error;
76 }
77 
78 int nfs3_setxattr(struct dentry *dentry, const char *name,
79 	     const void *value, size_t size, int flags)
80 {
81 	struct inode *inode = dentry->d_inode;
82 	struct posix_acl *acl;
83 	int type, error;
84 
85 	if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
86 		type = ACL_TYPE_ACCESS;
87 	else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
88 		type = ACL_TYPE_DEFAULT;
89 	else
90 		return -EOPNOTSUPP;
91 
92 	acl = posix_acl_from_xattr(value, size);
93 	if (IS_ERR(acl))
94 		return PTR_ERR(acl);
95 	error = nfs3_proc_setacl(inode, type, acl);
96 	posix_acl_release(acl);
97 
98 	return error;
99 }
100 
101 int nfs3_removexattr(struct dentry *dentry, const char *name)
102 {
103 	struct inode *inode = dentry->d_inode;
104 	int type;
105 
106 	if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
107 		type = ACL_TYPE_ACCESS;
108 	else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
109 		type = ACL_TYPE_DEFAULT;
110 	else
111 		return -EOPNOTSUPP;
112 
113 	return nfs3_proc_setacl(inode, type, NULL);
114 }
115 
116 static void __nfs3_forget_cached_acls(struct nfs_inode *nfsi)
117 {
118 	if (!IS_ERR(nfsi->acl_access)) {
119 		posix_acl_release(nfsi->acl_access);
120 		nfsi->acl_access = ERR_PTR(-EAGAIN);
121 	}
122 	if (!IS_ERR(nfsi->acl_default)) {
123 		posix_acl_release(nfsi->acl_default);
124 		nfsi->acl_default = ERR_PTR(-EAGAIN);
125 	}
126 }
127 
128 void nfs3_forget_cached_acls(struct inode *inode)
129 {
130 	dprintk("NFS: nfs3_forget_cached_acls(%s/%ld)\n", inode->i_sb->s_id,
131 		inode->i_ino);
132 	spin_lock(&inode->i_lock);
133 	__nfs3_forget_cached_acls(NFS_I(inode));
134 	spin_unlock(&inode->i_lock);
135 }
136 
137 static struct posix_acl *nfs3_get_cached_acl(struct inode *inode, int type)
138 {
139 	struct nfs_inode *nfsi = NFS_I(inode);
140 	struct posix_acl *acl = ERR_PTR(-EINVAL);
141 
142 	spin_lock(&inode->i_lock);
143 	switch(type) {
144 		case ACL_TYPE_ACCESS:
145 			acl = nfsi->acl_access;
146 			break;
147 
148 		case ACL_TYPE_DEFAULT:
149 			acl = nfsi->acl_default;
150 			break;
151 
152 		default:
153 			goto out;
154 	}
155 	if (IS_ERR(acl))
156 		acl = ERR_PTR(-EAGAIN);
157 	else
158 		acl = posix_acl_dup(acl);
159 out:
160 	spin_unlock(&inode->i_lock);
161 	dprintk("NFS: nfs3_get_cached_acl(%s/%ld, %d) = %p\n", inode->i_sb->s_id,
162 		inode->i_ino, type, acl);
163 	return acl;
164 }
165 
166 static void nfs3_cache_acls(struct inode *inode, struct posix_acl *acl,
167 		    struct posix_acl *dfacl)
168 {
169 	struct nfs_inode *nfsi = NFS_I(inode);
170 
171 	dprintk("nfs3_cache_acls(%s/%ld, %p, %p)\n", inode->i_sb->s_id,
172 		inode->i_ino, acl, dfacl);
173 	spin_lock(&inode->i_lock);
174 	__nfs3_forget_cached_acls(NFS_I(inode));
175 	nfsi->acl_access = posix_acl_dup(acl);
176 	nfsi->acl_default = posix_acl_dup(dfacl);
177 	spin_unlock(&inode->i_lock);
178 }
179 
180 struct posix_acl *nfs3_proc_getacl(struct inode *inode, int type)
181 {
182 	struct nfs_server *server = NFS_SERVER(inode);
183 	struct nfs_fattr fattr;
184 	struct page *pages[NFSACL_MAXPAGES] = { };
185 	struct nfs3_getaclargs args = {
186 		.fh = NFS_FH(inode),
187 		/* The xdr layer may allocate pages here. */
188 		.pages = pages,
189 	};
190 	struct nfs3_getaclres res = {
191 		.fattr =	&fattr,
192 	};
193 	struct rpc_message msg = {
194 		.rpc_argp	= &args,
195 		.rpc_resp	= &res,
196 	};
197 	struct posix_acl *acl;
198 	int status, count;
199 
200 	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
201 		return ERR_PTR(-EOPNOTSUPP);
202 
203 	status = nfs_revalidate_inode(server, inode);
204 	if (status < 0)
205 		return ERR_PTR(status);
206 	acl = nfs3_get_cached_acl(inode, type);
207 	if (acl != ERR_PTR(-EAGAIN))
208 		return acl;
209 	acl = NULL;
210 
211 	/*
212 	 * Only get the access acl when explicitly requested: We don't
213 	 * need it for access decisions, and only some applications use
214 	 * it. Applications which request the access acl first are not
215 	 * penalized from this optimization.
216 	 */
217 	if (type == ACL_TYPE_ACCESS)
218 		args.mask |= NFS_ACLCNT|NFS_ACL;
219 	if (S_ISDIR(inode->i_mode))
220 		args.mask |= NFS_DFACLCNT|NFS_DFACL;
221 	if (args.mask == 0)
222 		return NULL;
223 
224 	dprintk("NFS call getacl\n");
225 	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
226 	status = rpc_call_sync(server->client_acl, &msg, 0);
227 	dprintk("NFS reply getacl: %d\n", status);
228 
229 	/* pages may have been allocated at the xdr layer. */
230 	for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
231 		__free_page(args.pages[count]);
232 
233 	switch (status) {
234 		case 0:
235 			status = nfs_refresh_inode(inode, &fattr);
236 			break;
237 		case -EPFNOSUPPORT:
238 		case -EPROTONOSUPPORT:
239 			dprintk("NFS_V3_ACL extension not supported; disabling\n");
240 			server->caps &= ~NFS_CAP_ACLS;
241 		case -ENOTSUPP:
242 			status = -EOPNOTSUPP;
243 		default:
244 			goto getout;
245 	}
246 	if ((args.mask & res.mask) != args.mask) {
247 		status = -EIO;
248 		goto getout;
249 	}
250 
251 	if (res.acl_access != NULL) {
252 		if (posix_acl_equiv_mode(res.acl_access, NULL) == 0) {
253 			posix_acl_release(res.acl_access);
254 			res.acl_access = NULL;
255 		}
256 	}
257 	nfs3_cache_acls(inode, res.acl_access, res.acl_default);
258 
259 	switch(type) {
260 		case ACL_TYPE_ACCESS:
261 			acl = res.acl_access;
262 			res.acl_access = NULL;
263 			break;
264 
265 		case ACL_TYPE_DEFAULT:
266 			acl = res.acl_default;
267 			res.acl_default = NULL;
268 	}
269 
270 getout:
271 	posix_acl_release(res.acl_access);
272 	posix_acl_release(res.acl_default);
273 
274 	if (status != 0) {
275 		posix_acl_release(acl);
276 		acl = ERR_PTR(status);
277 	}
278 	return acl;
279 }
280 
281 static int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
282 		  struct posix_acl *dfacl)
283 {
284 	struct nfs_server *server = NFS_SERVER(inode);
285 	struct nfs_fattr fattr;
286 	struct page *pages[NFSACL_MAXPAGES] = { };
287 	struct nfs3_setaclargs args = {
288 		.inode = inode,
289 		.mask = NFS_ACL,
290 		.acl_access = acl,
291 		.pages = pages,
292 	};
293 	struct rpc_message msg = {
294 		.rpc_argp	= &args,
295 		.rpc_resp	= &fattr,
296 	};
297 	int status, count;
298 
299 	status = -EOPNOTSUPP;
300 	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
301 		goto out;
302 
303 	/* We are doing this here, because XDR marshalling can only
304 	   return -ENOMEM. */
305 	status = -ENOSPC;
306 	if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
307 		goto out;
308 	if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
309 		goto out;
310 	if (S_ISDIR(inode->i_mode)) {
311 		args.mask |= NFS_DFACL;
312 		args.acl_default = dfacl;
313 	}
314 
315 	dprintk("NFS call setacl\n");
316 	nfs_begin_data_update(inode);
317 	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
318 	status = rpc_call_sync(server->client_acl, &msg, 0);
319 	spin_lock(&inode->i_lock);
320 	NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ACCESS;
321 	spin_unlock(&inode->i_lock);
322 	nfs_end_data_update(inode);
323 	dprintk("NFS reply setacl: %d\n", status);
324 
325 	/* pages may have been allocated at the xdr layer. */
326 	for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
327 		__free_page(args.pages[count]);
328 
329 	switch (status) {
330 		case 0:
331 			status = nfs_refresh_inode(inode, &fattr);
332 			break;
333 		case -EPFNOSUPPORT:
334 		case -EPROTONOSUPPORT:
335 			dprintk("NFS_V3_ACL SETACL RPC not supported"
336 					"(will not retry)\n");
337 			server->caps &= ~NFS_CAP_ACLS;
338 		case -ENOTSUPP:
339 			status = -EOPNOTSUPP;
340 	}
341 out:
342 	return status;
343 }
344 
345 int nfs3_proc_setacl(struct inode *inode, int type, struct posix_acl *acl)
346 {
347 	struct posix_acl *alloc = NULL, *dfacl = NULL;
348 	int status;
349 
350 	if (S_ISDIR(inode->i_mode)) {
351 		switch(type) {
352 			case ACL_TYPE_ACCESS:
353 				alloc = dfacl = nfs3_proc_getacl(inode,
354 						ACL_TYPE_DEFAULT);
355 				if (IS_ERR(alloc))
356 					goto fail;
357 				break;
358 
359 			case ACL_TYPE_DEFAULT:
360 				dfacl = acl;
361 				alloc = acl = nfs3_proc_getacl(inode,
362 						ACL_TYPE_ACCESS);
363 				if (IS_ERR(alloc))
364 					goto fail;
365 				break;
366 
367 			default:
368 				return -EINVAL;
369 		}
370 	} else if (type != ACL_TYPE_ACCESS)
371 			return -EINVAL;
372 
373 	if (acl == NULL) {
374 		alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
375 		if (IS_ERR(alloc))
376 			goto fail;
377 	}
378 	status = nfs3_proc_setacls(inode, acl, dfacl);
379 	posix_acl_release(alloc);
380 	return status;
381 
382 fail:
383 	return PTR_ERR(alloc);
384 }
385 
386 int nfs3_proc_set_default_acl(struct inode *dir, struct inode *inode,
387 		mode_t mode)
388 {
389 	struct posix_acl *dfacl, *acl;
390 	int error = 0;
391 
392 	dfacl = nfs3_proc_getacl(dir, ACL_TYPE_DEFAULT);
393 	if (IS_ERR(dfacl)) {
394 		error = PTR_ERR(dfacl);
395 		return (error == -EOPNOTSUPP) ? 0 : error;
396 	}
397 	if (!dfacl)
398 		return 0;
399 	acl = posix_acl_clone(dfacl, GFP_KERNEL);
400 	error = -ENOMEM;
401 	if (!acl)
402 		goto out_release_dfacl;
403 	error = posix_acl_create_masq(acl, &mode);
404 	if (error < 0)
405 		goto out_release_acl;
406 	error = nfs3_proc_setacls(inode, acl, S_ISDIR(inode->i_mode) ?
407 						      dfacl : NULL);
408 out_release_acl:
409 	posix_acl_release(acl);
410 out_release_dfacl:
411 	posix_acl_release(dfacl);
412 	return error;
413 }
414