xref: /openbmc/linux/fs/nfs/nfs3acl.c (revision 827634ad)
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 struct posix_acl *nfs3_get_acl(struct inode *inode, int type)
15 {
16 	struct nfs_server *server = NFS_SERVER(inode);
17 	struct page *pages[NFSACL_MAXPAGES] = { };
18 	struct nfs3_getaclargs args = {
19 		.fh = NFS_FH(inode),
20 		/* The xdr layer may allocate pages here. */
21 		.pages = pages,
22 	};
23 	struct nfs3_getaclres res = {
24 		NULL,
25 	};
26 	struct rpc_message msg = {
27 		.rpc_argp	= &args,
28 		.rpc_resp	= &res,
29 	};
30 	int status, count;
31 
32 	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
33 		return ERR_PTR(-EOPNOTSUPP);
34 
35 	status = nfs_revalidate_inode(server, inode);
36 	if (status < 0)
37 		return ERR_PTR(status);
38 
39 	/*
40 	 * Only get the access acl when explicitly requested: We don't
41 	 * need it for access decisions, and only some applications use
42 	 * it. Applications which request the access acl first are not
43 	 * penalized from this optimization.
44 	 */
45 	if (type == ACL_TYPE_ACCESS)
46 		args.mask |= NFS_ACLCNT|NFS_ACL;
47 	if (S_ISDIR(inode->i_mode))
48 		args.mask |= NFS_DFACLCNT|NFS_DFACL;
49 	if (args.mask == 0)
50 		return NULL;
51 
52 	dprintk("NFS call getacl\n");
53 	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
54 	res.fattr = nfs_alloc_fattr();
55 	if (res.fattr == NULL)
56 		return ERR_PTR(-ENOMEM);
57 
58 	status = rpc_call_sync(server->client_acl, &msg, 0);
59 	dprintk("NFS reply getacl: %d\n", status);
60 
61 	/* pages may have been allocated at the xdr layer. */
62 	for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
63 		__free_page(args.pages[count]);
64 
65 	switch (status) {
66 		case 0:
67 			status = nfs_refresh_inode(inode, res.fattr);
68 			break;
69 		case -EPFNOSUPPORT:
70 		case -EPROTONOSUPPORT:
71 			dprintk("NFS_V3_ACL extension not supported; disabling\n");
72 			server->caps &= ~NFS_CAP_ACLS;
73 		case -ENOTSUPP:
74 			status = -EOPNOTSUPP;
75 		default:
76 			goto getout;
77 	}
78 	if ((args.mask & res.mask) != args.mask) {
79 		status = -EIO;
80 		goto getout;
81 	}
82 
83 	if (res.acl_access != NULL) {
84 		if ((posix_acl_equiv_mode(res.acl_access, NULL) == 0) ||
85 		    res.acl_access->a_count == 0) {
86 			posix_acl_release(res.acl_access);
87 			res.acl_access = NULL;
88 		}
89 	}
90 
91 	if (res.mask & NFS_ACL)
92 		set_cached_acl(inode, ACL_TYPE_ACCESS, res.acl_access);
93 	else
94 		forget_cached_acl(inode, ACL_TYPE_ACCESS);
95 
96 	if (res.mask & NFS_DFACL)
97 		set_cached_acl(inode, ACL_TYPE_DEFAULT, res.acl_default);
98 	else
99 		forget_cached_acl(inode, ACL_TYPE_DEFAULT);
100 
101 	nfs_free_fattr(res.fattr);
102 	if (type == ACL_TYPE_ACCESS) {
103 		posix_acl_release(res.acl_default);
104 		return res.acl_access;
105 	} else {
106 		posix_acl_release(res.acl_access);
107 		return res.acl_default;
108 	}
109 
110 getout:
111 	posix_acl_release(res.acl_access);
112 	posix_acl_release(res.acl_default);
113 	nfs_free_fattr(res.fattr);
114 	return ERR_PTR(status);
115 }
116 
117 static int __nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
118 		struct posix_acl *dfacl)
119 {
120 	struct nfs_server *server = NFS_SERVER(inode);
121 	struct nfs_fattr *fattr;
122 	struct page *pages[NFSACL_MAXPAGES];
123 	struct nfs3_setaclargs args = {
124 		.inode = inode,
125 		.mask = NFS_ACL,
126 		.acl_access = acl,
127 		.pages = pages,
128 	};
129 	struct rpc_message msg = {
130 		.rpc_argp	= &args,
131 		.rpc_resp	= &fattr,
132 	};
133 	int status = 0;
134 
135 	if (acl == NULL && (!S_ISDIR(inode->i_mode) || dfacl == NULL))
136 		goto out;
137 
138 	status = -EOPNOTSUPP;
139 	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
140 		goto out;
141 
142 	/* We are doing this here because XDR marshalling does not
143 	 * return any results, it BUGs. */
144 	status = -ENOSPC;
145 	if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
146 		goto out;
147 	if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
148 		goto out;
149 	if (S_ISDIR(inode->i_mode)) {
150 		args.mask |= NFS_DFACL;
151 		args.acl_default = dfacl;
152 		args.len = nfsacl_size(acl, dfacl);
153 	} else
154 		args.len = nfsacl_size(acl, NULL);
155 
156 	if (args.len > NFS_ACL_INLINE_BUFSIZE) {
157 		unsigned int npages = 1 + ((args.len - 1) >> PAGE_SHIFT);
158 
159 		status = -ENOMEM;
160 		do {
161 			args.pages[args.npages] = alloc_page(GFP_KERNEL);
162 			if (args.pages[args.npages] == NULL)
163 				goto out_freepages;
164 			args.npages++;
165 		} while (args.npages < npages);
166 	}
167 
168 	dprintk("NFS call setacl\n");
169 	status = -ENOMEM;
170 	fattr = nfs_alloc_fattr();
171 	if (fattr == NULL)
172 		goto out_freepages;
173 
174 	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
175 	msg.rpc_resp = fattr;
176 	status = rpc_call_sync(server->client_acl, &msg, 0);
177 	nfs_access_zap_cache(inode);
178 	nfs_zap_acl_cache(inode);
179 	dprintk("NFS reply setacl: %d\n", status);
180 
181 	switch (status) {
182 		case 0:
183 			status = nfs_refresh_inode(inode, fattr);
184 			set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
185 			set_cached_acl(inode, ACL_TYPE_DEFAULT, dfacl);
186 			break;
187 		case -EPFNOSUPPORT:
188 		case -EPROTONOSUPPORT:
189 			dprintk("NFS_V3_ACL SETACL RPC not supported"
190 					"(will not retry)\n");
191 			server->caps &= ~NFS_CAP_ACLS;
192 		case -ENOTSUPP:
193 			status = -EOPNOTSUPP;
194 	}
195 	nfs_free_fattr(fattr);
196 out_freepages:
197 	while (args.npages != 0) {
198 		args.npages--;
199 		__free_page(args.pages[args.npages]);
200 	}
201 out:
202 	return status;
203 }
204 
205 int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
206 		struct posix_acl *dfacl)
207 {
208 	int ret;
209 	ret = __nfs3_proc_setacls(inode, acl, dfacl);
210 	return (ret == -EOPNOTSUPP) ? 0 : ret;
211 
212 }
213 
214 int nfs3_set_acl(struct inode *inode, struct posix_acl *acl, int type)
215 {
216 	struct posix_acl *alloc = NULL, *dfacl = NULL;
217 	int status;
218 
219 	if (S_ISDIR(inode->i_mode)) {
220 		switch(type) {
221 		case ACL_TYPE_ACCESS:
222 			alloc = dfacl = get_acl(inode, ACL_TYPE_DEFAULT);
223 			if (IS_ERR(alloc))
224 				goto fail;
225 			break;
226 
227 		case ACL_TYPE_DEFAULT:
228 			dfacl = acl;
229 			alloc = acl = get_acl(inode, ACL_TYPE_ACCESS);
230 			if (IS_ERR(alloc))
231 				goto fail;
232 			break;
233 		}
234 	}
235 
236 	if (acl == NULL) {
237 		alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
238 		if (IS_ERR(alloc))
239 			goto fail;
240 	}
241 	status = __nfs3_proc_setacls(inode, acl, dfacl);
242 	posix_acl_release(alloc);
243 	return status;
244 
245 fail:
246 	return PTR_ERR(alloc);
247 }
248 
249 const struct xattr_handler *nfs3_xattr_handlers[] = {
250 	&posix_acl_access_xattr_handler,
251 	&posix_acl_default_xattr_handler,
252 	NULL,
253 };
254 
255 static int
256 nfs3_list_one_acl(struct inode *inode, int type, const char *name, void *data,
257 		size_t size, ssize_t *result)
258 {
259 	struct posix_acl *acl;
260 	char *p = data + *result;
261 
262 	acl = get_acl(inode, type);
263 	if (IS_ERR_OR_NULL(acl))
264 		return 0;
265 
266 	posix_acl_release(acl);
267 
268 	*result += strlen(name);
269 	*result += 1;
270 	if (!size)
271 		return 0;
272 	if (*result > size)
273 		return -ERANGE;
274 
275 	strcpy(p, name);
276 	return 0;
277 }
278 
279 ssize_t
280 nfs3_listxattr(struct dentry *dentry, char *data, size_t size)
281 {
282 	struct inode *inode = d_inode(dentry);
283 	ssize_t result = 0;
284 	int error;
285 
286 	error = nfs3_list_one_acl(inode, ACL_TYPE_ACCESS,
287 			POSIX_ACL_XATTR_ACCESS, data, size, &result);
288 	if (error)
289 		return error;
290 
291 	error = nfs3_list_one_acl(inode, ACL_TYPE_DEFAULT,
292 			POSIX_ACL_XATTR_DEFAULT, data, size, &result);
293 	if (error)
294 		return error;
295 	return result;
296 }
297