xref: /linux/fs/nfs/nfs3acl.c (revision f884ab15afdc5514e88105c92a4e2e1e6539869a)
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 
11 #define NFSDBG_FACILITY	NFSDBG_PROC
12 
13 ssize_t nfs3_listxattr(struct dentry *dentry, char *buffer, size_t size)
14 {
15 	struct inode *inode = dentry->d_inode;
16 	struct posix_acl *acl;
17 	int pos=0, len=0;
18 
19 #	define output(s) do {						\
20 			if (pos + sizeof(s) <= size) {			\
21 				memcpy(buffer + pos, s, sizeof(s));	\
22 				pos += sizeof(s);			\
23 			}						\
24 			len += sizeof(s);				\
25 		} while(0)
26 
27 	acl = nfs3_proc_getacl(inode, ACL_TYPE_ACCESS);
28 	if (IS_ERR(acl))
29 		return PTR_ERR(acl);
30 	if (acl) {
31 		output("system.posix_acl_access");
32 		posix_acl_release(acl);
33 	}
34 
35 	if (S_ISDIR(inode->i_mode)) {
36 		acl = nfs3_proc_getacl(inode, ACL_TYPE_DEFAULT);
37 		if (IS_ERR(acl))
38 			return PTR_ERR(acl);
39 		if (acl) {
40 			output("system.posix_acl_default");
41 			posix_acl_release(acl);
42 		}
43 	}
44 
45 #	undef output
46 
47 	if (!buffer || len <= size)
48 		return len;
49 	return -ERANGE;
50 }
51 
52 ssize_t nfs3_getxattr(struct dentry *dentry, const char *name,
53 		void *buffer, size_t size)
54 {
55 	struct inode *inode = dentry->d_inode;
56 	struct posix_acl *acl;
57 	int type, error = 0;
58 
59 	if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
60 		type = ACL_TYPE_ACCESS;
61 	else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
62 		type = ACL_TYPE_DEFAULT;
63 	else
64 		return -EOPNOTSUPP;
65 
66 	acl = nfs3_proc_getacl(inode, type);
67 	if (IS_ERR(acl))
68 		return PTR_ERR(acl);
69 	else if (acl) {
70 		if (type == ACL_TYPE_ACCESS && acl->a_count == 0)
71 			error = -ENODATA;
72 		else
73 			error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
74 		posix_acl_release(acl);
75 	} else
76 		error = -ENODATA;
77 
78 	return error;
79 }
80 
81 int nfs3_setxattr(struct dentry *dentry, const char *name,
82 	     const void *value, size_t size, int flags)
83 {
84 	struct inode *inode = dentry->d_inode;
85 	struct posix_acl *acl;
86 	int type, error;
87 
88 	if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
89 		type = ACL_TYPE_ACCESS;
90 	else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
91 		type = ACL_TYPE_DEFAULT;
92 	else
93 		return -EOPNOTSUPP;
94 
95 	acl = posix_acl_from_xattr(&init_user_ns, value, size);
96 	if (IS_ERR(acl))
97 		return PTR_ERR(acl);
98 	error = nfs3_proc_setacl(inode, type, acl);
99 	posix_acl_release(acl);
100 
101 	return error;
102 }
103 
104 int nfs3_removexattr(struct dentry *dentry, const char *name)
105 {
106 	struct inode *inode = dentry->d_inode;
107 	int type;
108 
109 	if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
110 		type = ACL_TYPE_ACCESS;
111 	else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
112 		type = ACL_TYPE_DEFAULT;
113 	else
114 		return -EOPNOTSUPP;
115 
116 	return nfs3_proc_setacl(inode, type, NULL);
117 }
118 
119 static void __nfs3_forget_cached_acls(struct nfs_inode *nfsi)
120 {
121 	if (!IS_ERR(nfsi->acl_access)) {
122 		posix_acl_release(nfsi->acl_access);
123 		nfsi->acl_access = ERR_PTR(-EAGAIN);
124 	}
125 	if (!IS_ERR(nfsi->acl_default)) {
126 		posix_acl_release(nfsi->acl_default);
127 		nfsi->acl_default = ERR_PTR(-EAGAIN);
128 	}
129 }
130 
131 void nfs3_forget_cached_acls(struct inode *inode)
132 {
133 	dprintk("NFS: nfs3_forget_cached_acls(%s/%ld)\n", inode->i_sb->s_id,
134 		inode->i_ino);
135 	spin_lock(&inode->i_lock);
136 	__nfs3_forget_cached_acls(NFS_I(inode));
137 	spin_unlock(&inode->i_lock);
138 }
139 
140 static struct posix_acl *nfs3_get_cached_acl(struct inode *inode, int type)
141 {
142 	struct nfs_inode *nfsi = NFS_I(inode);
143 	struct posix_acl *acl = ERR_PTR(-EINVAL);
144 
145 	spin_lock(&inode->i_lock);
146 	switch(type) {
147 		case ACL_TYPE_ACCESS:
148 			acl = nfsi->acl_access;
149 			break;
150 
151 		case ACL_TYPE_DEFAULT:
152 			acl = nfsi->acl_default;
153 			break;
154 
155 		default:
156 			goto out;
157 	}
158 	if (IS_ERR(acl))
159 		acl = ERR_PTR(-EAGAIN);
160 	else
161 		acl = posix_acl_dup(acl);
162 out:
163 	spin_unlock(&inode->i_lock);
164 	dprintk("NFS: nfs3_get_cached_acl(%s/%ld, %d) = %p\n", inode->i_sb->s_id,
165 		inode->i_ino, type, acl);
166 	return acl;
167 }
168 
169 static void nfs3_cache_acls(struct inode *inode, struct posix_acl *acl,
170 		    struct posix_acl *dfacl)
171 {
172 	struct nfs_inode *nfsi = NFS_I(inode);
173 
174 	dprintk("nfs3_cache_acls(%s/%ld, %p, %p)\n", inode->i_sb->s_id,
175 		inode->i_ino, acl, dfacl);
176 	spin_lock(&inode->i_lock);
177 	__nfs3_forget_cached_acls(NFS_I(inode));
178 	if (!IS_ERR(acl))
179 		nfsi->acl_access = posix_acl_dup(acl);
180 	if (!IS_ERR(dfacl))
181 		nfsi->acl_default = posix_acl_dup(dfacl);
182 	spin_unlock(&inode->i_lock);
183 }
184 
185 struct posix_acl *nfs3_proc_getacl(struct inode *inode, int type)
186 {
187 	struct nfs_server *server = NFS_SERVER(inode);
188 	struct page *pages[NFSACL_MAXPAGES] = { };
189 	struct nfs3_getaclargs args = {
190 		.fh = NFS_FH(inode),
191 		/* The xdr layer may allocate pages here. */
192 		.pages = pages,
193 	};
194 	struct nfs3_getaclres res = {
195 		NULL,
196 	};
197 	struct rpc_message msg = {
198 		.rpc_argp	= &args,
199 		.rpc_resp	= &res,
200 	};
201 	struct posix_acl *acl;
202 	int status, count;
203 
204 	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
205 		return ERR_PTR(-EOPNOTSUPP);
206 
207 	status = nfs_revalidate_inode(server, inode);
208 	if (status < 0)
209 		return ERR_PTR(status);
210 	acl = nfs3_get_cached_acl(inode, type);
211 	if (acl != ERR_PTR(-EAGAIN))
212 		return acl;
213 	acl = NULL;
214 
215 	/*
216 	 * Only get the access acl when explicitly requested: We don't
217 	 * need it for access decisions, and only some applications use
218 	 * it. Applications which request the access acl first are not
219 	 * penalized from this optimization.
220 	 */
221 	if (type == ACL_TYPE_ACCESS)
222 		args.mask |= NFS_ACLCNT|NFS_ACL;
223 	if (S_ISDIR(inode->i_mode))
224 		args.mask |= NFS_DFACLCNT|NFS_DFACL;
225 	if (args.mask == 0)
226 		return NULL;
227 
228 	dprintk("NFS call getacl\n");
229 	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
230 	res.fattr = nfs_alloc_fattr();
231 	if (res.fattr == NULL)
232 		return ERR_PTR(-ENOMEM);
233 
234 	status = rpc_call_sync(server->client_acl, &msg, 0);
235 	dprintk("NFS reply getacl: %d\n", status);
236 
237 	/* pages may have been allocated at the xdr layer. */
238 	for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
239 		__free_page(args.pages[count]);
240 
241 	switch (status) {
242 		case 0:
243 			status = nfs_refresh_inode(inode, res.fattr);
244 			break;
245 		case -EPFNOSUPPORT:
246 		case -EPROTONOSUPPORT:
247 			dprintk("NFS_V3_ACL extension not supported; disabling\n");
248 			server->caps &= ~NFS_CAP_ACLS;
249 		case -ENOTSUPP:
250 			status = -EOPNOTSUPP;
251 		default:
252 			goto getout;
253 	}
254 	if ((args.mask & res.mask) != args.mask) {
255 		status = -EIO;
256 		goto getout;
257 	}
258 
259 	if (res.acl_access != NULL) {
260 		if (posix_acl_equiv_mode(res.acl_access, NULL) == 0) {
261 			posix_acl_release(res.acl_access);
262 			res.acl_access = NULL;
263 		}
264 	}
265 	nfs3_cache_acls(inode,
266 		(res.mask & NFS_ACL)   ? res.acl_access  : ERR_PTR(-EINVAL),
267 		(res.mask & NFS_DFACL) ? res.acl_default : ERR_PTR(-EINVAL));
268 
269 	switch(type) {
270 		case ACL_TYPE_ACCESS:
271 			acl = res.acl_access;
272 			res.acl_access = NULL;
273 			break;
274 
275 		case ACL_TYPE_DEFAULT:
276 			acl = res.acl_default;
277 			res.acl_default = NULL;
278 	}
279 
280 getout:
281 	posix_acl_release(res.acl_access);
282 	posix_acl_release(res.acl_default);
283 	nfs_free_fattr(res.fattr);
284 
285 	if (status != 0) {
286 		posix_acl_release(acl);
287 		acl = ERR_PTR(status);
288 	}
289 	return acl;
290 }
291 
292 static int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
293 		  struct posix_acl *dfacl)
294 {
295 	struct nfs_server *server = NFS_SERVER(inode);
296 	struct nfs_fattr *fattr;
297 	struct page *pages[NFSACL_MAXPAGES];
298 	struct nfs3_setaclargs args = {
299 		.inode = inode,
300 		.mask = NFS_ACL,
301 		.acl_access = acl,
302 		.pages = pages,
303 	};
304 	struct rpc_message msg = {
305 		.rpc_argp	= &args,
306 		.rpc_resp	= &fattr,
307 	};
308 	int status;
309 
310 	status = -EOPNOTSUPP;
311 	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
312 		goto out;
313 
314 	/* We are doing this here because XDR marshalling does not
315 	 * return any results, it BUGs. */
316 	status = -ENOSPC;
317 	if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
318 		goto out;
319 	if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
320 		goto out;
321 	if (S_ISDIR(inode->i_mode)) {
322 		args.mask |= NFS_DFACL;
323 		args.acl_default = dfacl;
324 		args.len = nfsacl_size(acl, dfacl);
325 	} else
326 		args.len = nfsacl_size(acl, NULL);
327 
328 	if (args.len > NFS_ACL_INLINE_BUFSIZE) {
329 		unsigned int npages = 1 + ((args.len - 1) >> PAGE_SHIFT);
330 
331 		status = -ENOMEM;
332 		do {
333 			args.pages[args.npages] = alloc_page(GFP_KERNEL);
334 			if (args.pages[args.npages] == NULL)
335 				goto out_freepages;
336 			args.npages++;
337 		} while (args.npages < npages);
338 	}
339 
340 	dprintk("NFS call setacl\n");
341 	status = -ENOMEM;
342 	fattr = nfs_alloc_fattr();
343 	if (fattr == NULL)
344 		goto out_freepages;
345 
346 	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
347 	msg.rpc_resp = fattr;
348 	status = rpc_call_sync(server->client_acl, &msg, 0);
349 	nfs_access_zap_cache(inode);
350 	nfs_zap_acl_cache(inode);
351 	dprintk("NFS reply setacl: %d\n", status);
352 
353 	switch (status) {
354 		case 0:
355 			status = nfs_refresh_inode(inode, fattr);
356 			nfs3_cache_acls(inode, acl, dfacl);
357 			break;
358 		case -EPFNOSUPPORT:
359 		case -EPROTONOSUPPORT:
360 			dprintk("NFS_V3_ACL SETACL RPC not supported"
361 					"(will not retry)\n");
362 			server->caps &= ~NFS_CAP_ACLS;
363 		case -ENOTSUPP:
364 			status = -EOPNOTSUPP;
365 	}
366 	nfs_free_fattr(fattr);
367 out_freepages:
368 	while (args.npages != 0) {
369 		args.npages--;
370 		__free_page(args.pages[args.npages]);
371 	}
372 out:
373 	return status;
374 }
375 
376 int nfs3_proc_setacl(struct inode *inode, int type, struct posix_acl *acl)
377 {
378 	struct posix_acl *alloc = NULL, *dfacl = NULL;
379 	int status;
380 
381 	if (S_ISDIR(inode->i_mode)) {
382 		switch(type) {
383 			case ACL_TYPE_ACCESS:
384 				alloc = dfacl = nfs3_proc_getacl(inode,
385 						ACL_TYPE_DEFAULT);
386 				if (IS_ERR(alloc))
387 					goto fail;
388 				break;
389 
390 			case ACL_TYPE_DEFAULT:
391 				dfacl = acl;
392 				alloc = acl = nfs3_proc_getacl(inode,
393 						ACL_TYPE_ACCESS);
394 				if (IS_ERR(alloc))
395 					goto fail;
396 				break;
397 
398 			default:
399 				return -EINVAL;
400 		}
401 	} else if (type != ACL_TYPE_ACCESS)
402 			return -EINVAL;
403 
404 	if (acl == NULL) {
405 		alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
406 		if (IS_ERR(alloc))
407 			goto fail;
408 	}
409 	status = nfs3_proc_setacls(inode, acl, dfacl);
410 	posix_acl_release(alloc);
411 	return status;
412 
413 fail:
414 	return PTR_ERR(alloc);
415 }
416 
417 int nfs3_proc_set_default_acl(struct inode *dir, struct inode *inode,
418 		umode_t mode)
419 {
420 	struct posix_acl *dfacl, *acl;
421 	int error = 0;
422 
423 	dfacl = nfs3_proc_getacl(dir, ACL_TYPE_DEFAULT);
424 	if (IS_ERR(dfacl)) {
425 		error = PTR_ERR(dfacl);
426 		return (error == -EOPNOTSUPP) ? 0 : error;
427 	}
428 	if (!dfacl)
429 		return 0;
430 	acl = posix_acl_dup(dfacl);
431 	error = posix_acl_create(&acl, GFP_KERNEL, &mode);
432 	if (error < 0)
433 		goto out_release_dfacl;
434 	error = nfs3_proc_setacls(inode, acl, S_ISDIR(inode->i_mode) ?
435 						      dfacl : NULL);
436 	posix_acl_release(acl);
437 out_release_dfacl:
438 	posix_acl_release(dfacl);
439 	return error;
440 }
441