bde0fabfece0aeeaecd9ab4b1c2cf733009975b1
[linux-2.6.git] / 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         down(&inode->i_sb->s_vfs_rename_sem);
52         fromName = build_path_from_dentry(old_file);
53         toName = build_path_from_dentry(direntry);
54         up(&inode->i_sb->s_vfs_rename_sem);
55         if((fromName == NULL) || (toName == NULL)) {
56                 rc = -ENOMEM;
57                 goto cifs_hl_exit;
58         }
59
60         if (cifs_sb_target->tcon->ses->capabilities & CAP_UNIX)
61                 rc = CIFSUnixCreateHardLink(xid, pTcon, fromName, toName,
62                                             cifs_sb_target->local_nls, 
63                                             cifs_sb_target->mnt_cifs_flags &
64                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
65         else {
66                 rc = CIFSCreateHardLink(xid, pTcon, fromName, toName,
67                                         cifs_sb_target->local_nls, 
68                                         cifs_sb_target->mnt_cifs_flags &
69                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
70                 if(rc == -EIO)
71                         rc = -EOPNOTSUPP;  
72         }
73
74 /* if (!rc)     */
75         {
76                 /*   renew_parental_timestamps(old_file);
77                    inode->i_nlink++;
78                    mark_inode_dirty(inode);
79                    d_instantiate(direntry, inode); */
80                 /* BB add call to either mark inode dirty or refresh its data and timestamp to current time */
81         }
82         d_drop(direntry);       /* force new lookup from server */
83         cifsInode = CIFS_I(old_file->d_inode);
84         cifsInode->time = 0;    /* will force revalidate to go get info when needed */
85
86 cifs_hl_exit:
87         if (fromName)
88                 kfree(fromName);
89         if (toName)
90                 kfree(toName);
91         FreeXid(xid);
92         return rc;
93 }
94
95 int
96 cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
97 {
98         struct inode *inode = direntry->d_inode;
99         int rc = -EACCES;
100         int xid;
101         char *full_path = NULL;
102         char * target_path = ERR_PTR(-ENOMEM);
103         struct cifs_sb_info *cifs_sb;
104         struct cifsTconInfo *pTcon;
105
106         xid = GetXid();
107
108         down(&direntry->d_sb->s_vfs_rename_sem);
109         full_path = build_path_from_dentry(direntry);
110         up(&direntry->d_sb->s_vfs_rename_sem);
111
112         if (!full_path)
113                 goto out_no_free;
114
115         cFYI(1, ("Full path: %s inode = 0x%p", full_path, inode));
116         cifs_sb = CIFS_SB(inode->i_sb);
117         pTcon = cifs_sb->tcon;
118         target_path = kmalloc(PATH_MAX, GFP_KERNEL);
119         if (!target_path) {
120                 target_path = ERR_PTR(-ENOMEM);
121                 goto out;
122         }
123
124 /* BB add read reparse point symlink code and Unix extensions symlink code here BB */
125         if (pTcon->ses->capabilities & CAP_UNIX)
126                 rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
127                                              target_path,
128                                              PATH_MAX-1,
129                                              cifs_sb->local_nls);
130         else {
131                 /* rc = CIFSSMBQueryReparseLinkInfo */
132                 /* BB Add code to Query ReparsePoint info */
133                 /* BB Add MAC style xsymlink check here if enabled */
134         }
135
136         if (rc == 0) {
137
138 /* BB Add special case check for Samba DFS symlinks */
139
140                 target_path[PATH_MAX-1] = 0;
141         } else {
142                 kfree(target_path);
143                 target_path = ERR_PTR(rc);
144         }
145
146 out:
147         kfree(full_path);
148 out_no_free:
149         FreeXid(xid);
150         nd_set_link(nd, target_path);
151         return 0;
152 }
153
154 int
155 cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
156 {
157         int rc = -EOPNOTSUPP;
158         int xid;
159         struct cifs_sb_info *cifs_sb;
160         struct cifsTconInfo *pTcon;
161         char *full_path = NULL;
162         struct inode *newinode = NULL;
163
164         xid = GetXid();
165
166         cifs_sb = CIFS_SB(inode->i_sb);
167         pTcon = cifs_sb->tcon;
168
169         down(&inode->i_sb->s_vfs_rename_sem);
170         full_path = build_path_from_dentry(direntry);
171         up(&inode->i_sb->s_vfs_rename_sem);
172
173         if(full_path == NULL) {
174                 FreeXid(xid);
175                 return -ENOMEM;
176         }
177
178         cFYI(1, ("Full path: %s ", full_path));
179         cFYI(1, ("symname is %s", symname));
180
181         /* BB what if DFS and this volume is on different share? BB */
182         if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
183                 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
184                                            cifs_sb->local_nls);
185         /* else
186            rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,cifs_sb_target->local_nls); */
187
188         if (rc == 0) {
189                 if (pTcon->ses->capabilities & CAP_UNIX)
190                         rc = cifs_get_inode_info_unix(&newinode, full_path,
191                                                       inode->i_sb,xid);
192                 else
193                         rc = cifs_get_inode_info(&newinode, full_path, NULL,
194                                                  inode->i_sb,xid);
195
196                 if (rc != 0) {
197                         cFYI(1,
198                              ("Create symlink worked but get_inode_info failed with rc = %d ",
199                               rc));
200                 } else {
201                         direntry->d_op = &cifs_dentry_ops;
202                         d_instantiate(direntry, newinode);
203                 }
204         }
205
206         if (full_path)
207                 kfree(full_path);
208         FreeXid(xid);
209         return rc;
210 }
211
212 int
213 cifs_readlink(struct dentry *direntry, char __user *pBuffer, int buflen)
214 {
215         struct inode *inode = direntry->d_inode;
216         int rc = -EACCES;
217         int xid;
218         int oplock = FALSE;
219         struct cifs_sb_info *cifs_sb;
220         struct cifsTconInfo *pTcon;
221         char *full_path = NULL;
222         char *tmp_path =  NULL;
223         char * tmpbuffer;
224         unsigned char * referrals = NULL;
225         int num_referrals = 0;
226         int len;
227         __u16 fid;
228
229         xid = GetXid();
230         cifs_sb = CIFS_SB(inode->i_sb);
231         pTcon = cifs_sb->tcon;
232
233 /* BB would it be safe against deadlock to grab this sem 
234       even though rename itself grabs the sem and calls lookup? */
235 /*       down(&inode->i_sb->s_vfs_rename_sem);*/
236         full_path = build_path_from_dentry(direntry);
237 /*       up(&inode->i_sb->s_vfs_rename_sem);*/
238
239         if(full_path == NULL) {
240                 FreeXid(xid);
241                 return -ENOMEM;
242         }
243
244         cFYI(1,
245              ("Full path: %s inode = 0x%p pBuffer = 0x%p buflen = %d",
246               full_path, inode, pBuffer, buflen));
247         if(buflen > PATH_MAX)
248                 len = PATH_MAX;
249         else
250                 len = buflen;
251         tmpbuffer = kmalloc(len,GFP_KERNEL);   
252         if(tmpbuffer == NULL) {
253                 if (full_path)
254                         kfree(full_path);
255                 FreeXid(xid);
256                 return -ENOMEM;
257         }
258
259 /* BB add read reparse point symlink code and Unix extensions symlink code here BB */
260         if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
261                 rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
262                                 tmpbuffer,
263                                 len - 1,
264                                 cifs_sb->local_nls);
265         else {
266                 rc = CIFSSMBOpen(xid, pTcon, full_path, FILE_OPEN, GENERIC_READ,
267                                 OPEN_REPARSE_POINT,&fid, &oplock, NULL, 
268                                 cifs_sb->local_nls, 
269                                 cifs_sb->mnt_cifs_flags & 
270                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
271                 if(!rc) {
272                         rc = CIFSSMBQueryReparseLinkInfo(xid, pTcon, full_path,
273                                 tmpbuffer,
274                                 len - 1, 
275                                 fid,
276                                 cifs_sb->local_nls);
277                         if(CIFSSMBClose(xid, pTcon, fid)) {
278                                 cFYI(1,("Error closing junction point (open for ioctl)"));
279                         }
280                         if(rc == -EIO) {
281                                 /* Query if DFS Junction */
282                                 tmp_path =
283                                         kmalloc(MAX_TREE_SIZE + MAX_PATHCONF + 1,
284                                                 GFP_KERNEL);
285                                 if (tmp_path) {
286                                         strncpy(tmp_path, pTcon->treeName, MAX_TREE_SIZE);
287                                         strncat(tmp_path, full_path, MAX_PATHCONF);
288                                         rc = get_dfs_path(xid, pTcon->ses, tmp_path,
289                                                 cifs_sb->local_nls,
290                                                 &num_referrals, &referrals,
291                                                 cifs_sb->mnt_cifs_flags &
292                                                     CIFS_MOUNT_MAP_SPECIAL_CHR);
293                                         cFYI(1,("Get DFS for %s rc = %d ",tmp_path, rc));
294                                         if((num_referrals == 0) && (rc == 0))
295                                                 rc = -EACCES;
296                                         else {
297                                                 cFYI(1,("num referral: %d",num_referrals));
298                                                 if(referrals) {
299                                                         cFYI(1,("referral string: %s ",referrals));
300                                                         strncpy(tmpbuffer, referrals, len-1);                            
301                                                 }
302                                         }
303                                         if(referrals)
304                                                 kfree(referrals);
305                                         kfree(tmp_path);
306 }
307                                 /* BB add code like else decode referrals then memcpy to
308                                   tmpbuffer and free referrals string array BB */
309                         }
310                 }
311         }
312         /* BB Anything else to do to handle recursive links? */
313         /* BB Should we be using page ops here? */
314
315         /* BB null terminate returned string in pBuffer? BB */
316         if (rc == 0) {
317                 rc = vfs_readlink(direntry, pBuffer, len, tmpbuffer);
318                 cFYI(1,
319                      ("vfs_readlink called from cifs_readlink returned %d",
320                       rc));
321         }
322
323         if (tmpbuffer) {
324                 kfree(tmpbuffer);
325         }
326         if (full_path) {
327                 kfree(full_path);
328         }
329         FreeXid(xid);
330         return rc;
331 }
332
333 void cifs_put_link(struct dentry *direntry, struct nameidata *nd)
334 {
335         char *p = nd_get_link(nd);
336         if (!IS_ERR(p))
337                 kfree(p);
338 }