Merge master.kernel.org:/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog
[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         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 void *
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 NULL;    /* No cookie */
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                         if (pTcon->nocase)
202                                 direntry->d_op = &cifs_ci_dentry_ops;
203                         else
204                                 direntry->d_op = &cifs_dentry_ops;
205                         d_instantiate(direntry, newinode);
206                 }
207         }
208
209         if (full_path)
210                 kfree(full_path);
211         FreeXid(xid);
212         return rc;
213 }
214
215 int
216 cifs_readlink(struct dentry *direntry, char __user *pBuffer, int buflen)
217 {
218         struct inode *inode = direntry->d_inode;
219         int rc = -EACCES;
220         int xid;
221         int oplock = FALSE;
222         struct cifs_sb_info *cifs_sb;
223         struct cifsTconInfo *pTcon;
224         char *full_path = NULL;
225         char *tmp_path =  NULL;
226         char * tmpbuffer;
227         unsigned char * referrals = NULL;
228         int num_referrals = 0;
229         int len;
230         __u16 fid;
231
232         xid = GetXid();
233         cifs_sb = CIFS_SB(inode->i_sb);
234         pTcon = cifs_sb->tcon;
235
236 /* BB would it be safe against deadlock to grab this sem 
237       even though rename itself grabs the sem and calls lookup? */
238 /*       down(&inode->i_sb->s_vfs_rename_sem);*/
239         full_path = build_path_from_dentry(direntry);
240 /*       up(&inode->i_sb->s_vfs_rename_sem);*/
241
242         if(full_path == NULL) {
243                 FreeXid(xid);
244                 return -ENOMEM;
245         }
246
247         cFYI(1,
248              ("Full path: %s inode = 0x%p pBuffer = 0x%p buflen = %d",
249               full_path, inode, pBuffer, buflen));
250         if(buflen > PATH_MAX)
251                 len = PATH_MAX;
252         else
253                 len = buflen;
254         tmpbuffer = kmalloc(len,GFP_KERNEL);   
255         if(tmpbuffer == NULL) {
256                 if (full_path)
257                         kfree(full_path);
258                 FreeXid(xid);
259                 return -ENOMEM;
260         }
261
262 /* BB add read reparse point symlink code and Unix extensions symlink code here BB */
263         if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
264                 rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
265                                 tmpbuffer,
266                                 len - 1,
267                                 cifs_sb->local_nls);
268         else {
269                 rc = CIFSSMBOpen(xid, pTcon, full_path, FILE_OPEN, GENERIC_READ,
270                                 OPEN_REPARSE_POINT,&fid, &oplock, NULL, 
271                                 cifs_sb->local_nls, 
272                                 cifs_sb->mnt_cifs_flags & 
273                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
274                 if(!rc) {
275                         rc = CIFSSMBQueryReparseLinkInfo(xid, pTcon, full_path,
276                                 tmpbuffer,
277                                 len - 1, 
278                                 fid,
279                                 cifs_sb->local_nls);
280                         if(CIFSSMBClose(xid, pTcon, fid)) {
281                                 cFYI(1,("Error closing junction point (open for ioctl)"));
282                         }
283                         if(rc == -EIO) {
284                                 /* Query if DFS Junction */
285                                 tmp_path =
286                                         kmalloc(MAX_TREE_SIZE + MAX_PATHCONF + 1,
287                                                 GFP_KERNEL);
288                                 if (tmp_path) {
289                                         strncpy(tmp_path, pTcon->treeName, MAX_TREE_SIZE);
290                                         strncat(tmp_path, full_path, MAX_PATHCONF);
291                                         rc = get_dfs_path(xid, pTcon->ses, tmp_path,
292                                                 cifs_sb->local_nls,
293                                                 &num_referrals, &referrals,
294                                                 cifs_sb->mnt_cifs_flags &
295                                                     CIFS_MOUNT_MAP_SPECIAL_CHR);
296                                         cFYI(1,("Get DFS for %s rc = %d ",tmp_path, rc));
297                                         if((num_referrals == 0) && (rc == 0))
298                                                 rc = -EACCES;
299                                         else {
300                                                 cFYI(1,("num referral: %d",num_referrals));
301                                                 if(referrals) {
302                                                         cFYI(1,("referral string: %s ",referrals));
303                                                         strncpy(tmpbuffer, referrals, len-1);                            
304                                                 }
305                                         }
306                                         if(referrals)
307                                                 kfree(referrals);
308                                         kfree(tmp_path);
309 }
310                                 /* BB add code like else decode referrals then memcpy to
311                                   tmpbuffer and free referrals string array BB */
312                         }
313                 }
314         }
315         /* BB Anything else to do to handle recursive links? */
316         /* BB Should we be using page ops here? */
317
318         /* BB null terminate returned string in pBuffer? BB */
319         if (rc == 0) {
320                 rc = vfs_readlink(direntry, pBuffer, len, tmpbuffer);
321                 cFYI(1,
322                      ("vfs_readlink called from cifs_readlink returned %d",
323                       rc));
324         }
325
326         if (tmpbuffer) {
327                 kfree(tmpbuffer);
328         }
329         if (full_path) {
330                 kfree(full_path);
331         }
332         FreeXid(xid);
333         return rc;
334 }
335
336 void cifs_put_link(struct dentry *direntry, struct nameidata *nd, void *cookie)
337 {
338         char *p = nd_get_link(nd);
339         if (!IS_ERR(p))
340                 kfree(p);
341 }