usbfs: fix race between open and unregister
[linux-2.6/mini2440.git] / fs / nfs / nfs3acl.c
blob423842f51ac91b6c447ce708dd31a2ab6cc513f1
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>
8 #include "internal.h"
10 #define NFSDBG_FACILITY NFSDBG_PROC
12 ssize_t nfs3_listxattr(struct dentry *dentry, char *buffer, size_t size)
14 struct inode *inode = dentry->d_inode;
15 struct posix_acl *acl;
16 int pos=0, len=0;
18 # define output(s) do { \
19 if (pos + sizeof(s) <= size) { \
20 memcpy(buffer + pos, s, sizeof(s)); \
21 pos += sizeof(s); \
22 } \
23 len += sizeof(s); \
24 } while(0)
26 acl = nfs3_proc_getacl(inode, ACL_TYPE_ACCESS);
27 if (IS_ERR(acl))
28 return PTR_ERR(acl);
29 if (acl) {
30 output("system.posix_acl_access");
31 posix_acl_release(acl);
34 if (S_ISDIR(inode->i_mode)) {
35 acl = nfs3_proc_getacl(inode, ACL_TYPE_DEFAULT);
36 if (IS_ERR(acl))
37 return PTR_ERR(acl);
38 if (acl) {
39 output("system.posix_acl_default");
40 posix_acl_release(acl);
44 # undef output
46 if (!buffer || len <= size)
47 return len;
48 return -ERANGE;
51 ssize_t nfs3_getxattr(struct dentry *dentry, const char *name,
52 void *buffer, size_t size)
54 struct inode *inode = dentry->d_inode;
55 struct posix_acl *acl;
56 int type, error = 0;
58 if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
59 type = ACL_TYPE_ACCESS;
60 else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
61 type = ACL_TYPE_DEFAULT;
62 else
63 return -EOPNOTSUPP;
65 acl = nfs3_proc_getacl(inode, type);
66 if (IS_ERR(acl))
67 return PTR_ERR(acl);
68 else if (acl) {
69 if (type == ACL_TYPE_ACCESS && acl->a_count == 0)
70 error = -ENODATA;
71 else
72 error = posix_acl_to_xattr(acl, buffer, size);
73 posix_acl_release(acl);
74 } else
75 error = -ENODATA;
77 return error;
80 int nfs3_setxattr(struct dentry *dentry, const char *name,
81 const void *value, size_t size, int flags)
83 struct inode *inode = dentry->d_inode;
84 struct posix_acl *acl;
85 int type, error;
87 if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
88 type = ACL_TYPE_ACCESS;
89 else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
90 type = ACL_TYPE_DEFAULT;
91 else
92 return -EOPNOTSUPP;
94 acl = posix_acl_from_xattr(value, size);
95 if (IS_ERR(acl))
96 return PTR_ERR(acl);
97 error = nfs3_proc_setacl(inode, type, acl);
98 posix_acl_release(acl);
100 return error;
103 int nfs3_removexattr(struct dentry *dentry, const char *name)
105 struct inode *inode = dentry->d_inode;
106 int type;
108 if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
109 type = ACL_TYPE_ACCESS;
110 else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
111 type = ACL_TYPE_DEFAULT;
112 else
113 return -EOPNOTSUPP;
115 return nfs3_proc_setacl(inode, type, NULL);
118 static void __nfs3_forget_cached_acls(struct nfs_inode *nfsi)
120 if (!IS_ERR(nfsi->acl_access)) {
121 posix_acl_release(nfsi->acl_access);
122 nfsi->acl_access = ERR_PTR(-EAGAIN);
124 if (!IS_ERR(nfsi->acl_default)) {
125 posix_acl_release(nfsi->acl_default);
126 nfsi->acl_default = ERR_PTR(-EAGAIN);
130 void nfs3_forget_cached_acls(struct inode *inode)
132 dprintk("NFS: nfs3_forget_cached_acls(%s/%ld)\n", inode->i_sb->s_id,
133 inode->i_ino);
134 spin_lock(&inode->i_lock);
135 __nfs3_forget_cached_acls(NFS_I(inode));
136 spin_unlock(&inode->i_lock);
139 static struct posix_acl *nfs3_get_cached_acl(struct inode *inode, int type)
141 struct nfs_inode *nfsi = NFS_I(inode);
142 struct posix_acl *acl = ERR_PTR(-EINVAL);
144 spin_lock(&inode->i_lock);
145 switch(type) {
146 case ACL_TYPE_ACCESS:
147 acl = nfsi->acl_access;
148 break;
150 case ACL_TYPE_DEFAULT:
151 acl = nfsi->acl_default;
152 break;
154 default:
155 goto out;
157 if (IS_ERR(acl))
158 acl = ERR_PTR(-EAGAIN);
159 else
160 acl = posix_acl_dup(acl);
161 out:
162 spin_unlock(&inode->i_lock);
163 dprintk("NFS: nfs3_get_cached_acl(%s/%ld, %d) = %p\n", inode->i_sb->s_id,
164 inode->i_ino, type, acl);
165 return acl;
168 static void nfs3_cache_acls(struct inode *inode, struct posix_acl *acl,
169 struct posix_acl *dfacl)
171 struct nfs_inode *nfsi = NFS_I(inode);
173 dprintk("nfs3_cache_acls(%s/%ld, %p, %p)\n", inode->i_sb->s_id,
174 inode->i_ino, acl, dfacl);
175 spin_lock(&inode->i_lock);
176 __nfs3_forget_cached_acls(NFS_I(inode));
177 if (!IS_ERR(acl))
178 nfsi->acl_access = posix_acl_dup(acl);
179 if (!IS_ERR(dfacl))
180 nfsi->acl_default = posix_acl_dup(dfacl);
181 spin_unlock(&inode->i_lock);
184 struct posix_acl *nfs3_proc_getacl(struct inode *inode, int type)
186 struct nfs_server *server = NFS_SERVER(inode);
187 struct nfs_fattr fattr;
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,
194 struct nfs3_getaclres res = {
195 .fattr = &fattr,
197 struct rpc_message msg = {
198 .rpc_argp = &args,
199 .rpc_resp = &res,
201 struct posix_acl *acl;
202 int status, count;
204 if (!nfs_server_capable(inode, NFS_CAP_ACLS))
205 return ERR_PTR(-EOPNOTSUPP);
207 status = nfs_revalidate_inode(server, inode);
208 if (status < 0)
209 return ERR_PTR(status);
210 if (NFS_I(inode)->cache_validity & NFS_INO_INVALID_ACL)
211 nfs_zap_acl_cache(inode);
212 acl = nfs3_get_cached_acl(inode, type);
213 if (acl != ERR_PTR(-EAGAIN))
214 return acl;
215 acl = NULL;
218 * Only get the access acl when explicitly requested: We don't
219 * need it for access decisions, and only some applications use
220 * it. Applications which request the access acl first are not
221 * penalized from this optimization.
223 if (type == ACL_TYPE_ACCESS)
224 args.mask |= NFS_ACLCNT|NFS_ACL;
225 if (S_ISDIR(inode->i_mode))
226 args.mask |= NFS_DFACLCNT|NFS_DFACL;
227 if (args.mask == 0)
228 return NULL;
230 dprintk("NFS call getacl\n");
231 msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
232 status = rpc_call_sync(server->client_acl, &msg, 0);
233 dprintk("NFS reply getacl: %d\n", status);
235 /* pages may have been allocated at the xdr layer. */
236 for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
237 __free_page(args.pages[count]);
239 switch (status) {
240 case 0:
241 status = nfs_refresh_inode(inode, &fattr);
242 break;
243 case -EPFNOSUPPORT:
244 case -EPROTONOSUPPORT:
245 dprintk("NFS_V3_ACL extension not supported; disabling\n");
246 server->caps &= ~NFS_CAP_ACLS;
247 case -ENOTSUPP:
248 status = -EOPNOTSUPP;
249 default:
250 goto getout;
252 if ((args.mask & res.mask) != args.mask) {
253 status = -EIO;
254 goto getout;
257 if (res.acl_access != NULL) {
258 if (posix_acl_equiv_mode(res.acl_access, NULL) == 0) {
259 posix_acl_release(res.acl_access);
260 res.acl_access = NULL;
263 nfs3_cache_acls(inode,
264 (res.mask & NFS_ACL) ? res.acl_access : ERR_PTR(-EINVAL),
265 (res.mask & NFS_DFACL) ? res.acl_default : ERR_PTR(-EINVAL));
267 switch(type) {
268 case ACL_TYPE_ACCESS:
269 acl = res.acl_access;
270 res.acl_access = NULL;
271 break;
273 case ACL_TYPE_DEFAULT:
274 acl = res.acl_default;
275 res.acl_default = NULL;
278 getout:
279 posix_acl_release(res.acl_access);
280 posix_acl_release(res.acl_default);
282 if (status != 0) {
283 posix_acl_release(acl);
284 acl = ERR_PTR(status);
286 return acl;
289 static int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
290 struct posix_acl *dfacl)
292 struct nfs_server *server = NFS_SERVER(inode);
293 struct nfs_fattr fattr;
294 struct page *pages[NFSACL_MAXPAGES] = { };
295 struct nfs3_setaclargs args = {
296 .inode = inode,
297 .mask = NFS_ACL,
298 .acl_access = acl,
299 .pages = pages,
301 struct rpc_message msg = {
302 .rpc_argp = &args,
303 .rpc_resp = &fattr,
305 int status, count;
307 status = -EOPNOTSUPP;
308 if (!nfs_server_capable(inode, NFS_CAP_ACLS))
309 goto out;
311 /* We are doing this here, because XDR marshalling can only
312 return -ENOMEM. */
313 status = -ENOSPC;
314 if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
315 goto out;
316 if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
317 goto out;
318 if (S_ISDIR(inode->i_mode)) {
319 args.mask |= NFS_DFACL;
320 args.acl_default = dfacl;
323 dprintk("NFS call setacl\n");
324 msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
325 status = rpc_call_sync(server->client_acl, &msg, 0);
326 nfs_access_zap_cache(inode);
327 nfs_zap_acl_cache(inode);
328 dprintk("NFS reply setacl: %d\n", status);
330 /* pages may have been allocated at the xdr layer. */
331 for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
332 __free_page(args.pages[count]);
334 switch (status) {
335 case 0:
336 status = nfs_refresh_inode(inode, &fattr);
337 nfs3_cache_acls(inode, acl, dfacl);
338 break;
339 case -EPFNOSUPPORT:
340 case -EPROTONOSUPPORT:
341 dprintk("NFS_V3_ACL SETACL RPC not supported"
342 "(will not retry)\n");
343 server->caps &= ~NFS_CAP_ACLS;
344 case -ENOTSUPP:
345 status = -EOPNOTSUPP;
347 out:
348 return status;
351 int nfs3_proc_setacl(struct inode *inode, int type, struct posix_acl *acl)
353 struct posix_acl *alloc = NULL, *dfacl = NULL;
354 int status;
356 if (S_ISDIR(inode->i_mode)) {
357 switch(type) {
358 case ACL_TYPE_ACCESS:
359 alloc = dfacl = nfs3_proc_getacl(inode,
360 ACL_TYPE_DEFAULT);
361 if (IS_ERR(alloc))
362 goto fail;
363 break;
365 case ACL_TYPE_DEFAULT:
366 dfacl = acl;
367 alloc = acl = nfs3_proc_getacl(inode,
368 ACL_TYPE_ACCESS);
369 if (IS_ERR(alloc))
370 goto fail;
371 break;
373 default:
374 return -EINVAL;
376 } else if (type != ACL_TYPE_ACCESS)
377 return -EINVAL;
379 if (acl == NULL) {
380 alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
381 if (IS_ERR(alloc))
382 goto fail;
384 status = nfs3_proc_setacls(inode, acl, dfacl);
385 posix_acl_release(alloc);
386 return status;
388 fail:
389 return PTR_ERR(alloc);
392 int nfs3_proc_set_default_acl(struct inode *dir, struct inode *inode,
393 mode_t mode)
395 struct posix_acl *dfacl, *acl;
396 int error = 0;
398 dfacl = nfs3_proc_getacl(dir, ACL_TYPE_DEFAULT);
399 if (IS_ERR(dfacl)) {
400 error = PTR_ERR(dfacl);
401 return (error == -EOPNOTSUPP) ? 0 : error;
403 if (!dfacl)
404 return 0;
405 acl = posix_acl_clone(dfacl, GFP_KERNEL);
406 error = -ENOMEM;
407 if (!acl)
408 goto out_release_dfacl;
409 error = posix_acl_create_masq(acl, &mode);
410 if (error < 0)
411 goto out_release_acl;
412 error = nfs3_proc_setacls(inode, acl, S_ISDIR(inode->i_mode) ?
413 dfacl : NULL);
414 out_release_acl:
415 posix_acl_release(acl);
416 out_release_dfacl:
417 posix_acl_release(dfacl);
418 return error;