Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
[linux-2.6] / fs / nfs / nfs3acl.c
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 #include "internal.h"
9
10 #define NFSDBG_FACILITY NFSDBG_PROC
11
12 ssize_t nfs3_listxattr(struct dentry *dentry, char *buffer, size_t size)
13 {
14         struct inode *inode = dentry->d_inode;
15         struct posix_acl *acl;
16         int pos=0, len=0;
17
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)
25
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);
32         }
33
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);
41                 }
42         }
43
44 #       undef output
45
46         if (!buffer || len <= size)
47                 return len;
48         return -ERANGE;
49 }
50
51 ssize_t nfs3_getxattr(struct dentry *dentry, const char *name,
52                 void *buffer, size_t size)
53 {
54         struct inode *inode = dentry->d_inode;
55         struct posix_acl *acl;
56         int type, error = 0;
57
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;
64
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;
76
77         return error;
78 }
79
80 int nfs3_setxattr(struct dentry *dentry, const char *name,
81              const void *value, size_t size, int flags)
82 {
83         struct inode *inode = dentry->d_inode;
84         struct posix_acl *acl;
85         int type, error;
86
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;
93
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);
99
100         return error;
101 }
102
103 int nfs3_removexattr(struct dentry *dentry, const char *name)
104 {
105         struct inode *inode = dentry->d_inode;
106         int type;
107
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;
114
115         return nfs3_proc_setacl(inode, type, NULL);
116 }
117
118 static void __nfs3_forget_cached_acls(struct nfs_inode *nfsi)
119 {
120         if (!IS_ERR(nfsi->acl_access)) {
121                 posix_acl_release(nfsi->acl_access);
122                 nfsi->acl_access = ERR_PTR(-EAGAIN);
123         }
124         if (!IS_ERR(nfsi->acl_default)) {
125                 posix_acl_release(nfsi->acl_default);
126                 nfsi->acl_default = ERR_PTR(-EAGAIN);
127         }
128 }
129
130 void nfs3_forget_cached_acls(struct inode *inode)
131 {
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);
137 }
138
139 static struct posix_acl *nfs3_get_cached_acl(struct inode *inode, int type)
140 {
141         struct nfs_inode *nfsi = NFS_I(inode);
142         struct posix_acl *acl = ERR_PTR(-EINVAL);
143
144         spin_lock(&inode->i_lock);
145         switch(type) {
146                 case ACL_TYPE_ACCESS:
147                         acl = nfsi->acl_access;
148                         break;
149
150                 case ACL_TYPE_DEFAULT:
151                         acl = nfsi->acl_default;
152                         break;
153
154                 default:
155                         goto out;
156         }
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;
166 }
167
168 static void nfs3_cache_acls(struct inode *inode, struct posix_acl *acl,
169                     struct posix_acl *dfacl)
170 {
171         struct nfs_inode *nfsi = NFS_I(inode);
172
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);
182 }
183
184 struct posix_acl *nfs3_proc_getacl(struct inode *inode, int type)
185 {
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,
193         };
194         struct nfs3_getaclres res = {
195                 .fattr =        &fattr,
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         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;
216
217         /*
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.
222          */
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;
229
230         dprintk("NFS call getacl\n");
231         msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
232         nfs_fattr_init(&fattr);
233         status = rpc_call_sync(server->client_acl, &msg, 0);
234         dprintk("NFS reply getacl: %d\n", status);
235
236         /* pages may have been allocated at the xdr layer. */
237         for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
238                 __free_page(args.pages[count]);
239
240         switch (status) {
241                 case 0:
242                         status = nfs_refresh_inode(inode, &fattr);
243                         break;
244                 case -EPFNOSUPPORT:
245                 case -EPROTONOSUPPORT:
246                         dprintk("NFS_V3_ACL extension not supported; disabling\n");
247                         server->caps &= ~NFS_CAP_ACLS;
248                 case -ENOTSUPP:
249                         status = -EOPNOTSUPP;
250                 default:
251                         goto getout;
252         }
253         if ((args.mask & res.mask) != args.mask) {
254                 status = -EIO;
255                 goto getout;
256         }
257
258         if (res.acl_access != NULL) {
259                 if (posix_acl_equiv_mode(res.acl_access, NULL) == 0) {
260                         posix_acl_release(res.acl_access);
261                         res.acl_access = NULL;
262                 }
263         }
264         nfs3_cache_acls(inode,
265                 (res.mask & NFS_ACL)   ? res.acl_access  : ERR_PTR(-EINVAL),
266                 (res.mask & NFS_DFACL) ? res.acl_default : ERR_PTR(-EINVAL));
267
268         switch(type) {
269                 case ACL_TYPE_ACCESS:
270                         acl = res.acl_access;
271                         res.acl_access = NULL;
272                         break;
273
274                 case ACL_TYPE_DEFAULT:
275                         acl = res.acl_default;
276                         res.acl_default = NULL;
277         }
278
279 getout:
280         posix_acl_release(res.acl_access);
281         posix_acl_release(res.acl_default);
282
283         if (status != 0) {
284                 posix_acl_release(acl);
285                 acl = ERR_PTR(status);
286         }
287         return acl;
288 }
289
290 static int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
291                   struct posix_acl *dfacl)
292 {
293         struct nfs_server *server = NFS_SERVER(inode);
294         struct nfs_fattr fattr;
295         struct page *pages[NFSACL_MAXPAGES];
296         struct nfs3_setaclargs args = {
297                 .inode = inode,
298                 .mask = NFS_ACL,
299                 .acl_access = acl,
300                 .pages = pages,
301         };
302         struct rpc_message msg = {
303                 .rpc_argp       = &args,
304                 .rpc_resp       = &fattr,
305         };
306         int status;
307
308         status = -EOPNOTSUPP;
309         if (!nfs_server_capable(inode, NFS_CAP_ACLS))
310                 goto out;
311
312         /* We are doing this here, because XDR marshalling can only
313            return -ENOMEM. */
314         status = -ENOSPC;
315         if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
316                 goto out;
317         if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
318                 goto out;
319         if (S_ISDIR(inode->i_mode)) {
320                 args.mask |= NFS_DFACL;
321                 args.acl_default = dfacl;
322                 args.len = nfsacl_size(acl, dfacl);
323         } else
324                 args.len = nfsacl_size(acl, NULL);
325
326         if (args.len > NFS_ACL_INLINE_BUFSIZE) {
327                 unsigned int npages = 1 + ((args.len - 1) >> PAGE_SHIFT);
328
329                 status = -ENOMEM;
330                 do {
331                         args.pages[args.npages] = alloc_page(GFP_KERNEL);
332                         if (args.pages[args.npages] == NULL)
333                                 goto out_freepages;
334                         args.npages++;
335                 } while (args.npages < npages);
336         }
337
338         dprintk("NFS call setacl\n");
339         msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
340         nfs_fattr_init(&fattr);
341         status = rpc_call_sync(server->client_acl, &msg, 0);
342         nfs_access_zap_cache(inode);
343         nfs_zap_acl_cache(inode);
344         dprintk("NFS reply setacl: %d\n", status);
345
346         switch (status) {
347                 case 0:
348                         status = nfs_refresh_inode(inode, &fattr);
349                         nfs3_cache_acls(inode, acl, dfacl);
350                         break;
351                 case -EPFNOSUPPORT:
352                 case -EPROTONOSUPPORT:
353                         dprintk("NFS_V3_ACL SETACL RPC not supported"
354                                         "(will not retry)\n");
355                         server->caps &= ~NFS_CAP_ACLS;
356                 case -ENOTSUPP:
357                         status = -EOPNOTSUPP;
358         }
359 out_freepages:
360         while (args.npages != 0) {
361                 args.npages--;
362                 __free_page(args.pages[args.npages]);
363         }
364 out:
365         return status;
366 }
367
368 int nfs3_proc_setacl(struct inode *inode, int type, struct posix_acl *acl)
369 {
370         struct posix_acl *alloc = NULL, *dfacl = NULL;
371         int status;
372
373         if (S_ISDIR(inode->i_mode)) {
374                 switch(type) {
375                         case ACL_TYPE_ACCESS:
376                                 alloc = dfacl = nfs3_proc_getacl(inode,
377                                                 ACL_TYPE_DEFAULT);
378                                 if (IS_ERR(alloc))
379                                         goto fail;
380                                 break;
381
382                         case ACL_TYPE_DEFAULT:
383                                 dfacl = acl;
384                                 alloc = acl = nfs3_proc_getacl(inode,
385                                                 ACL_TYPE_ACCESS);
386                                 if (IS_ERR(alloc))
387                                         goto fail;
388                                 break;
389
390                         default:
391                                 return -EINVAL;
392                 }
393         } else if (type != ACL_TYPE_ACCESS)
394                         return -EINVAL;
395
396         if (acl == NULL) {
397                 alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
398                 if (IS_ERR(alloc))
399                         goto fail;
400         }
401         status = nfs3_proc_setacls(inode, acl, dfacl);
402         posix_acl_release(alloc);
403         return status;
404
405 fail:
406         return PTR_ERR(alloc);
407 }
408
409 int nfs3_proc_set_default_acl(struct inode *dir, struct inode *inode,
410                 mode_t mode)
411 {
412         struct posix_acl *dfacl, *acl;
413         int error = 0;
414
415         dfacl = nfs3_proc_getacl(dir, ACL_TYPE_DEFAULT);
416         if (IS_ERR(dfacl)) {
417                 error = PTR_ERR(dfacl);
418                 return (error == -EOPNOTSUPP) ? 0 : error;
419         }
420         if (!dfacl)
421                 return 0;
422         acl = posix_acl_clone(dfacl, GFP_KERNEL);
423         error = -ENOMEM;
424         if (!acl)
425                 goto out_release_dfacl;
426         error = posix_acl_create_masq(acl, &mode);
427         if (error < 0)
428                 goto out_release_acl;
429         error = nfs3_proc_setacls(inode, acl, S_ISDIR(inode->i_mode) ?
430                                                       dfacl : NULL);
431 out_release_acl:
432         posix_acl_release(acl);
433 out_release_dfacl:
434         posix_acl_release(dfacl);
435         return error;
436 }