Merge git://git.infradead.org/~dwmw2/cafe-2.6
[linux-2.6] / fs / cifs / link.c
1 /*
2  *   fs/cifs/link.c
3  *
4  *   Copyright (C) International Business Machines  Corp., 2002,2003
5  *   Author(s): Steve French (sfrench@us.ibm.com)
6  *
7  *   This library is free software; you can redistribute it and/or modify
8  *   it under the terms of the GNU Lesser General Public License as published
9  *   by the Free Software Foundation; either version 2.1 of the License, or
10  *   (at your option) any later version.
11  *
12  *   This library is distributed in the hope that it will be useful,
13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
15  *   the GNU Lesser General Public License for more details.
16  *
17  *   You should have received a copy of the GNU Lesser General Public License
18  *   along with this library; if not, write to the Free Software
19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20  */
21 #include <linux/fs.h>
22 #include <linux/stat.h>
23 #include <linux/namei.h>
24 #include "cifsfs.h"
25 #include "cifspdu.h"
26 #include "cifsglob.h"
27 #include "cifsproto.h"
28 #include "cifs_debug.h"
29 #include "cifs_fs_sb.h"
30
31 int
32 cifs_hardlink(struct dentry *old_file, struct inode *inode,
33               struct dentry *direntry)
34 {
35         int rc = -EACCES;
36         int xid;
37         char *fromName = NULL;
38         char *toName = NULL;
39         struct cifs_sb_info *cifs_sb_target;
40         struct cifsTconInfo *pTcon;
41         struct cifsInodeInfo *cifsInode;
42
43         xid = GetXid();
44
45         cifs_sb_target = CIFS_SB(inode->i_sb);
46         pTcon = cifs_sb_target->tcon;
47
48 /* No need to check for cross device links since server will do that
49    BB note DFS case in future though (when we may have to check) */
50
51         fromName = build_path_from_dentry(old_file);
52         toName = build_path_from_dentry(direntry);
53         if((fromName == NULL) || (toName == NULL)) {
54                 rc = -ENOMEM;
55                 goto cifs_hl_exit;
56         }
57
58         if (cifs_sb_target->tcon->ses->capabilities & CAP_UNIX)
59                 rc = CIFSUnixCreateHardLink(xid, pTcon, fromName, toName,
60                                             cifs_sb_target->local_nls, 
61                                             cifs_sb_target->mnt_cifs_flags &
62                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
63         else {
64                 rc = CIFSCreateHardLink(xid, pTcon, fromName, toName,
65                                         cifs_sb_target->local_nls, 
66                                         cifs_sb_target->mnt_cifs_flags &
67                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
68                 if((rc == -EIO) || (rc == -EINVAL))
69                         rc = -EOPNOTSUPP;  
70         }
71
72 /* if (!rc)     */
73         {
74                 /*   renew_parental_timestamps(old_file);
75                    inode->i_nlink++;
76                    mark_inode_dirty(inode);
77                    d_instantiate(direntry, inode); */
78                 /* BB add call to either mark inode dirty or refresh its data and timestamp to current time */
79         }
80         d_drop(direntry);       /* force new lookup from server */
81         cifsInode = CIFS_I(old_file->d_inode);
82         cifsInode->time = 0;    /* will force revalidate to go get info when needed */
83
84 cifs_hl_exit:
85         kfree(fromName);
86         kfree(toName);
87         FreeXid(xid);
88         return rc;
89 }
90
91 void *
92 cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
93 {
94         struct inode *inode = direntry->d_inode;
95         int rc = -EACCES;
96         int xid;
97         char *full_path = NULL;
98         char * target_path = ERR_PTR(-ENOMEM);
99         struct cifs_sb_info *cifs_sb;
100         struct cifsTconInfo *pTcon;
101
102         xid = GetXid();
103
104         full_path = build_path_from_dentry(direntry);
105
106         if (!full_path)
107                 goto out_no_free;
108
109         cFYI(1, ("Full path: %s inode = 0x%p", full_path, inode));
110         cifs_sb = CIFS_SB(inode->i_sb);
111         pTcon = cifs_sb->tcon;
112         target_path = kmalloc(PATH_MAX, GFP_KERNEL);
113         if (!target_path) {
114                 target_path = ERR_PTR(-ENOMEM);
115                 goto out;
116         }
117
118 /* BB add read reparse point symlink code and Unix extensions symlink code here BB */
119         if (pTcon->ses->capabilities & CAP_UNIX)
120                 rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
121                                              target_path,
122                                              PATH_MAX-1,
123                                              cifs_sb->local_nls);
124         else {
125                 /* rc = CIFSSMBQueryReparseLinkInfo */
126                 /* BB Add code to Query ReparsePoint info */
127                 /* BB Add MAC style xsymlink check here if enabled */
128         }
129
130         if (rc == 0) {
131
132 /* BB Add special case check for Samba DFS symlinks */
133
134                 target_path[PATH_MAX-1] = 0;
135         } else {
136                 kfree(target_path);
137                 target_path = ERR_PTR(rc);
138         }
139
140 out:
141         kfree(full_path);
142 out_no_free:
143         FreeXid(xid);
144         nd_set_link(nd, target_path);
145         return NULL;    /* No cookie */
146 }
147
148 int
149 cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
150 {
151         int rc = -EOPNOTSUPP;
152         int xid;
153         struct cifs_sb_info *cifs_sb;
154         struct cifsTconInfo *pTcon;
155         char *full_path = NULL;
156         struct inode *newinode = NULL;
157
158         xid = GetXid();
159
160         cifs_sb = CIFS_SB(inode->i_sb);
161         pTcon = cifs_sb->tcon;
162
163         full_path = build_path_from_dentry(direntry);
164
165         if(full_path == NULL) {
166                 FreeXid(xid);
167                 return -ENOMEM;
168         }
169
170         cFYI(1, ("Full path: %s", full_path));
171         cFYI(1, ("symname is %s", symname));
172
173         /* BB what if DFS and this volume is on different share? BB */
174         if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
175                 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
176                                            cifs_sb->local_nls);
177         /* else
178            rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,cifs_sb_target->local_nls); */
179
180         if (rc == 0) {
181                 if (pTcon->ses->capabilities & CAP_UNIX)
182                         rc = cifs_get_inode_info_unix(&newinode, full_path,
183                                                       inode->i_sb,xid);
184                 else
185                         rc = cifs_get_inode_info(&newinode, full_path, NULL,
186                                                  inode->i_sb,xid);
187
188                 if (rc != 0) {
189                         cFYI(1, ("Create symlink ok, getinodeinfo fail rc = %d",
190                               rc));
191                 } else {
192                         if (pTcon->nocase)
193                                 direntry->d_op = &cifs_ci_dentry_ops;
194                         else
195                                 direntry->d_op = &cifs_dentry_ops;
196                         d_instantiate(direntry, newinode);
197                 }
198         }
199
200         kfree(full_path);
201         FreeXid(xid);
202         return rc;
203 }
204
205 int
206 cifs_readlink(struct dentry *direntry, char __user *pBuffer, int buflen)
207 {
208         struct inode *inode = direntry->d_inode;
209         int rc = -EACCES;
210         int xid;
211         int oplock = FALSE;
212         struct cifs_sb_info *cifs_sb;
213         struct cifsTconInfo *pTcon;
214         char *full_path = NULL;
215         char *tmp_path =  NULL;
216         char * tmpbuffer;
217         unsigned char * referrals = NULL;
218         int num_referrals = 0;
219         int len;
220         __u16 fid;
221
222         xid = GetXid();
223         cifs_sb = CIFS_SB(inode->i_sb);
224         pTcon = cifs_sb->tcon;
225
226 /* BB would it be safe against deadlock to grab this sem 
227       even though rename itself grabs the sem and calls lookup? */
228 /*       mutex_lock(&inode->i_sb->s_vfs_rename_mutex);*/
229         full_path = build_path_from_dentry(direntry);
230 /*       mutex_unlock(&inode->i_sb->s_vfs_rename_mutex);*/
231
232         if(full_path == NULL) {
233                 FreeXid(xid);
234                 return -ENOMEM;
235         }
236
237         cFYI(1,
238              ("Full path: %s inode = 0x%p pBuffer = 0x%p buflen = %d",
239               full_path, inode, pBuffer, buflen));
240         if(buflen > PATH_MAX)
241                 len = PATH_MAX;
242         else
243                 len = buflen;
244         tmpbuffer = kmalloc(len,GFP_KERNEL);   
245         if(tmpbuffer == NULL) {
246                 kfree(full_path);
247                 FreeXid(xid);
248                 return -ENOMEM;
249         }
250
251 /* BB add read reparse point symlink code and Unix extensions symlink code here BB */
252         if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
253                 rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
254                                 tmpbuffer,
255                                 len - 1,
256                                 cifs_sb->local_nls);
257         else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
258                 cERROR(1,("SFU style symlinks not implemented yet"));
259                 /* add open and read as in fs/cifs/inode.c */
260         
261         } else {
262                 rc = CIFSSMBOpen(xid, pTcon, full_path, FILE_OPEN, GENERIC_READ,
263                                 OPEN_REPARSE_POINT,&fid, &oplock, NULL, 
264                                 cifs_sb->local_nls, 
265                                 cifs_sb->mnt_cifs_flags & 
266                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
267                 if(!rc) {
268                         rc = CIFSSMBQueryReparseLinkInfo(xid, pTcon, full_path,
269                                 tmpbuffer,
270                                 len - 1, 
271                                 fid,
272                                 cifs_sb->local_nls);
273                         if(CIFSSMBClose(xid, pTcon, fid)) {
274                                 cFYI(1,("Error closing junction point (open for ioctl)"));
275                         }
276                         if(rc == -EIO) {
277                                 /* Query if DFS Junction */
278                                 tmp_path =
279                                         kmalloc(MAX_TREE_SIZE + MAX_PATHCONF + 1,
280                                                 GFP_KERNEL);
281                                 if (tmp_path) {
282                                         strncpy(tmp_path, pTcon->treeName, MAX_TREE_SIZE);
283                                         strncat(tmp_path, full_path, MAX_PATHCONF);
284                                         rc = get_dfs_path(xid, pTcon->ses, tmp_path,
285                                                 cifs_sb->local_nls,
286                                                 &num_referrals, &referrals,
287                                                 cifs_sb->mnt_cifs_flags &
288                                                     CIFS_MOUNT_MAP_SPECIAL_CHR);
289                                         cFYI(1,("Get DFS for %s rc = %d ",tmp_path, rc));
290                                         if((num_referrals == 0) && (rc == 0))
291                                                 rc = -EACCES;
292                                         else {
293                                                 cFYI(1,("num referral: %d",num_referrals));
294                                                 if(referrals) {
295                                                         cFYI(1,("referral string: %s",referrals));
296                                                         strncpy(tmpbuffer, referrals, len-1);                            
297                                                 }
298                                         }
299                                         kfree(referrals);
300                                         kfree(tmp_path);
301 }
302                                 /* BB add code like else decode referrals then memcpy to
303                                   tmpbuffer and free referrals string array BB */
304                         }
305                 }
306         }
307         /* BB Anything else to do to handle recursive links? */
308         /* BB Should we be using page ops here? */
309
310         /* BB null terminate returned string in pBuffer? BB */
311         if (rc == 0) {
312                 rc = vfs_readlink(direntry, pBuffer, len, tmpbuffer);
313                 cFYI(1,
314                      ("vfs_readlink called from cifs_readlink returned %d",
315                       rc));
316         }
317
318         kfree(tmpbuffer);
319         kfree(full_path);
320         FreeXid(xid);
321         return rc;
322 }
323
324 void cifs_put_link(struct dentry *direntry, struct nameidata *nd, void *cookie)
325 {
326         char *p = nd_get_link(nd);
327         if (!IS_ERR(p))
328                 kfree(p);
329 }