xref: /linux/fs/nfs/nfs3acl.c (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
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 struct posix_acl *nfs3_get_acl(struct inode *inode, int type)
14 {
15 	struct nfs_server *server = NFS_SERVER(inode);
16 	struct page *pages[NFSACL_MAXPAGES] = { };
17 	struct nfs3_getaclargs args = {
18 		.fh = NFS_FH(inode),
19 		/* The xdr layer may allocate pages here. */
20 		.pages = pages,
21 	};
22 	struct nfs3_getaclres res = {
23 		NULL,
24 	};
25 	struct rpc_message msg = {
26 		.rpc_argp	= &args,
27 		.rpc_resp	= &res,
28 	};
29 	int status, count;
30 
31 	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
32 		return ERR_PTR(-EOPNOTSUPP);
33 
34 	status = nfs_revalidate_inode(server, inode);
35 	if (status < 0)
36 		return ERR_PTR(status);
37 
38 	/*
39 	 * Only get the access acl when explicitly requested: We don't
40 	 * need it for access decisions, and only some applications use
41 	 * it. Applications which request the access acl first are not
42 	 * penalized from this optimization.
43 	 */
44 	if (type == ACL_TYPE_ACCESS)
45 		args.mask |= NFS_ACLCNT|NFS_ACL;
46 	if (S_ISDIR(inode->i_mode))
47 		args.mask |= NFS_DFACLCNT|NFS_DFACL;
48 	if (args.mask == 0)
49 		return NULL;
50 
51 	dprintk("NFS call getacl\n");
52 	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
53 	res.fattr = nfs_alloc_fattr();
54 	if (res.fattr == NULL)
55 		return ERR_PTR(-ENOMEM);
56 
57 	status = rpc_call_sync(server->client_acl, &msg, 0);
58 	dprintk("NFS reply getacl: %d\n", status);
59 
60 	/* pages may have been allocated at the xdr layer. */
61 	for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
62 		__free_page(args.pages[count]);
63 
64 	switch (status) {
65 		case 0:
66 			status = nfs_refresh_inode(inode, res.fattr);
67 			break;
68 		case -EPFNOSUPPORT:
69 		case -EPROTONOSUPPORT:
70 			dprintk("NFS_V3_ACL extension not supported; disabling\n");
71 			server->caps &= ~NFS_CAP_ACLS;
72 		case -ENOTSUPP:
73 			status = -EOPNOTSUPP;
74 		default:
75 			goto getout;
76 	}
77 	if ((args.mask & res.mask) != args.mask) {
78 		status = -EIO;
79 		goto getout;
80 	}
81 
82 	if (res.acl_access != NULL) {
83 		if ((posix_acl_equiv_mode(res.acl_access, NULL) == 0) ||
84 		    res.acl_access->a_count == 0) {
85 			posix_acl_release(res.acl_access);
86 			res.acl_access = NULL;
87 		}
88 	}
89 
90 	if (res.mask & NFS_ACL)
91 		set_cached_acl(inode, ACL_TYPE_ACCESS, res.acl_access);
92 	else
93 		forget_cached_acl(inode, ACL_TYPE_ACCESS);
94 
95 	if (res.mask & NFS_DFACL)
96 		set_cached_acl(inode, ACL_TYPE_DEFAULT, res.acl_default);
97 	else
98 		forget_cached_acl(inode, ACL_TYPE_DEFAULT);
99 
100 	nfs_free_fattr(res.fattr);
101 	if (type == ACL_TYPE_ACCESS) {
102 		posix_acl_release(res.acl_default);
103 		return res.acl_access;
104 	} else {
105 		posix_acl_release(res.acl_access);
106 		return res.acl_default;
107 	}
108 
109 getout:
110 	posix_acl_release(res.acl_access);
111 	posix_acl_release(res.acl_default);
112 	nfs_free_fattr(res.fattr);
113 	return ERR_PTR(status);
114 }
115 
116 static int __nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
117 		struct posix_acl *dfacl)
118 {
119 	struct nfs_server *server = NFS_SERVER(inode);
120 	struct nfs_fattr *fattr;
121 	struct page *pages[NFSACL_MAXPAGES];
122 	struct nfs3_setaclargs args = {
123 		.inode = inode,
124 		.mask = NFS_ACL,
125 		.acl_access = acl,
126 		.pages = pages,
127 	};
128 	struct rpc_message msg = {
129 		.rpc_argp	= &args,
130 		.rpc_resp	= &fattr,
131 	};
132 	int status = 0;
133 
134 	if (acl == NULL && (!S_ISDIR(inode->i_mode) || dfacl == NULL))
135 		goto out;
136 
137 	status = -EOPNOTSUPP;
138 	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
139 		goto out;
140 
141 	/* We are doing this here because XDR marshalling does not
142 	 * return any results, it BUGs. */
143 	status = -ENOSPC;
144 	if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
145 		goto out;
146 	if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
147 		goto out;
148 	if (S_ISDIR(inode->i_mode)) {
149 		args.mask |= NFS_DFACL;
150 		args.acl_default = dfacl;
151 		args.len = nfsacl_size(acl, dfacl);
152 	} else
153 		args.len = nfsacl_size(acl, NULL);
154 
155 	if (args.len > NFS_ACL_INLINE_BUFSIZE) {
156 		unsigned int npages = 1 + ((args.len - 1) >> PAGE_SHIFT);
157 
158 		status = -ENOMEM;
159 		do {
160 			args.pages[args.npages] = alloc_page(GFP_KERNEL);
161 			if (args.pages[args.npages] == NULL)
162 				goto out_freepages;
163 			args.npages++;
164 		} while (args.npages < npages);
165 	}
166 
167 	dprintk("NFS call setacl\n");
168 	status = -ENOMEM;
169 	fattr = nfs_alloc_fattr();
170 	if (fattr == NULL)
171 		goto out_freepages;
172 
173 	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
174 	msg.rpc_resp = fattr;
175 	status = rpc_call_sync(server->client_acl, &msg, 0);
176 	nfs_access_zap_cache(inode);
177 	nfs_zap_acl_cache(inode);
178 	dprintk("NFS reply setacl: %d\n", status);
179 
180 	switch (status) {
181 		case 0:
182 			status = nfs_refresh_inode(inode, fattr);
183 			set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
184 			set_cached_acl(inode, ACL_TYPE_DEFAULT, dfacl);
185 			break;
186 		case -EPFNOSUPPORT:
187 		case -EPROTONOSUPPORT:
188 			dprintk("NFS_V3_ACL SETACL RPC not supported"
189 					"(will not retry)\n");
190 			server->caps &= ~NFS_CAP_ACLS;
191 		case -ENOTSUPP:
192 			status = -EOPNOTSUPP;
193 	}
194 	nfs_free_fattr(fattr);
195 out_freepages:
196 	while (args.npages != 0) {
197 		args.npages--;
198 		__free_page(args.pages[args.npages]);
199 	}
200 out:
201 	return status;
202 }
203 
204 int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
205 		struct posix_acl *dfacl)
206 {
207 	int ret;
208 	ret = __nfs3_proc_setacls(inode, acl, dfacl);
209 	return (ret == -EOPNOTSUPP) ? 0 : ret;
210 
211 }
212 
213 int nfs3_set_acl(struct inode *inode, struct posix_acl *acl, int type)
214 {
215 	struct posix_acl *alloc = NULL, *dfacl = NULL;
216 	int status;
217 
218 	if (S_ISDIR(inode->i_mode)) {
219 		switch(type) {
220 		case ACL_TYPE_ACCESS:
221 			alloc = dfacl = get_acl(inode, ACL_TYPE_DEFAULT);
222 			if (IS_ERR(alloc))
223 				goto fail;
224 			break;
225 
226 		case ACL_TYPE_DEFAULT:
227 			dfacl = acl;
228 			alloc = acl = get_acl(inode, ACL_TYPE_ACCESS);
229 			if (IS_ERR(alloc))
230 				goto fail;
231 			break;
232 		}
233 	}
234 
235 	if (acl == NULL) {
236 		alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
237 		if (IS_ERR(alloc))
238 			goto fail;
239 	}
240 	status = __nfs3_proc_setacls(inode, acl, dfacl);
241 	posix_acl_release(alloc);
242 	return status;
243 
244 fail:
245 	return PTR_ERR(alloc);
246 }
247 
248 const struct xattr_handler *nfs3_xattr_handlers[] = {
249 	&posix_acl_access_xattr_handler,
250 	&posix_acl_default_xattr_handler,
251 	NULL,
252 };
253 
254 static int
255 nfs3_list_one_acl(struct inode *inode, int type, const char *name, void *data,
256 		size_t size, ssize_t *result)
257 {
258 	struct posix_acl *acl;
259 	char *p = data + *result;
260 
261 	acl = get_acl(inode, type);
262 	if (IS_ERR_OR_NULL(acl))
263 		return 0;
264 
265 	posix_acl_release(acl);
266 
267 	*result += strlen(name);
268 	*result += 1;
269 	if (!size)
270 		return 0;
271 	if (*result > size)
272 		return -ERANGE;
273 
274 	strcpy(p, name);
275 	return 0;
276 }
277 
278 ssize_t
279 nfs3_listxattr(struct dentry *dentry, char *data, size_t size)
280 {
281 	struct inode *inode = dentry->d_inode;
282 	ssize_t result = 0;
283 	int error;
284 
285 	error = nfs3_list_one_acl(inode, ACL_TYPE_ACCESS,
286 			POSIX_ACL_XATTR_ACCESS, data, size, &result);
287 	if (error)
288 		return error;
289 
290 	error = nfs3_list_one_acl(inode, ACL_TYPE_DEFAULT,
291 			POSIX_ACL_XATTR_DEFAULT, data, size, &result);
292 	if (error)
293 		return error;
294 	return result;
295 }
296