Merge branch 'upstream'
[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         mutex_lock(&inode->i_sb->s_vfs_rename_mutex);
52         fromName = build_path_from_dentry(old_file);
53         toName = build_path_from_dentry(direntry);
54         mutex_unlock(&inode->i_sb->s_vfs_rename_mutex);
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) || (rc == -EINVAL))
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         kfree(fromName);
88         kfree(toName);
89         FreeXid(xid);
90         return rc;
91 }
92
93 void *
94 cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
95 {
96         struct inode *inode = direntry->d_inode;
97         int rc = -EACCES;
98         int xid;
99         char *full_path = NULL;
100         char * target_path = ERR_PTR(-ENOMEM);
101         struct cifs_sb_info *cifs_sb;
102         struct cifsTconInfo *pTcon;
103
104         xid = GetXid();
105
106         mutex_lock(&direntry->d_sb->s_vfs_rename_mutex);
107         full_path = build_path_from_dentry(direntry);
108         mutex_unlock(&direntry->d_sb->s_vfs_rename_mutex);
109
110         if (!full_path)
111                 goto out_no_free;
112
113         cFYI(1, ("Full path: %s inode = 0x%p", full_path, inode));
114         cifs_sb = CIFS_SB(inode->i_sb);
115         pTcon = cifs_sb->tcon;
116         target_path = kmalloc(PATH_MAX, GFP_KERNEL);
117         if (!target_path) {
118                 target_path = ERR_PTR(-ENOMEM);
119                 goto out;
120         }
121
122 /* BB add read reparse point symlink code and Unix extensions symlink code here BB */
123         if (pTcon->ses->capabilities & CAP_UNIX)
124                 rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
125                                              target_path,
126                                              PATH_MAX-1,
127                                              cifs_sb->local_nls);
128         else {
129                 /* rc = CIFSSMBQueryReparseLinkInfo */
130                 /* BB Add code to Query ReparsePoint info */
131                 /* BB Add MAC style xsymlink check here if enabled */
132         }
133
134         if (rc == 0) {
135
136 /* BB Add special case check for Samba DFS symlinks */
137
138                 target_path[PATH_MAX-1] = 0;
139         } else {
140                 kfree(target_path);
141                 target_path = ERR_PTR(rc);
142         }
143
144 out:
145         kfree(full_path);
146 out_no_free:
147         FreeXid(xid);
148         nd_set_link(nd, target_path);
149         return NULL;    /* No cookie */
150 }
151
152 int
153 cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
154 {
155         int rc = -EOPNOTSUPP;
156         int xid;
157         struct cifs_sb_info *cifs_sb;
158         struct cifsTconInfo *pTcon;
159         char *full_path = NULL;
160         struct inode *newinode = NULL;
161
162         xid = GetXid();
163
164         cifs_sb = CIFS_SB(inode->i_sb);
165         pTcon = cifs_sb->tcon;
166
167         mutex_lock(&inode->i_sb->s_vfs_rename_mutex);
168         full_path = build_path_from_dentry(direntry);
169         mutex_unlock(&inode->i_sb->s_vfs_rename_mutex);
170
171         if(full_path == NULL) {
172                 FreeXid(xid);
173                 return -ENOMEM;
174         }
175
176         cFYI(1, ("Full path: %s ", full_path));
177         cFYI(1, ("symname is %s", symname));
178
179         /* BB what if DFS and this volume is on different share? BB */
180         if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
181                 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
182                                            cifs_sb->local_nls);
183         /* else
184            rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,cifs_sb_target->local_nls); */
185
186         if (rc == 0) {
187                 if (pTcon->ses->capabilities & CAP_UNIX)
188                         rc = cifs_get_inode_info_unix(&newinode, full_path,
189                                                       inode->i_sb,xid);
190                 else
191                         rc = cifs_get_inode_info(&newinode, full_path, NULL,
192                                                  inode->i_sb,xid);
193
194                 if (rc != 0) {
195                         cFYI(1,
196                              ("Create symlink worked but get_inode_info failed with rc = %d ",
197                               rc));
198                 } else {
199                         if (pTcon->nocase)
200                                 direntry->d_op = &cifs_ci_dentry_ops;
201                         else
202                                 direntry->d_op = &cifs_dentry_ops;
203                         d_instantiate(direntry, newinode);
204                 }
205         }
206
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 /*       mutex_lock(&inode->i_sb->s_vfs_rename_mutex);*/
236         full_path = build_path_from_dentry(direntry);
237 /*       mutex_unlock(&inode->i_sb->s_vfs_rename_mutex);*/
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                 kfree(full_path);
254                 FreeXid(xid);
255                 return -ENOMEM;
256         }
257
258 /* BB add read reparse point symlink code and Unix extensions symlink code here BB */
259         if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
260                 rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
261                                 tmpbuffer,
262                                 len - 1,
263                                 cifs_sb->local_nls);
264         else {
265                 rc = CIFSSMBOpen(xid, pTcon, full_path, FILE_OPEN, GENERIC_READ,
266                                 OPEN_REPARSE_POINT,&fid, &oplock, NULL, 
267                                 cifs_sb->local_nls, 
268                                 cifs_sb->mnt_cifs_flags & 
269                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
270                 if(!rc) {
271                         rc = CIFSSMBQueryReparseLinkInfo(xid, pTcon, full_path,
272                                 tmpbuffer,
273                                 len - 1, 
274                                 fid,
275                                 cifs_sb->local_nls);
276                         if(CIFSSMBClose(xid, pTcon, fid)) {
277                                 cFYI(1,("Error closing junction point (open for ioctl)"));
278                         }
279                         if(rc == -EIO) {
280                                 /* Query if DFS Junction */
281                                 tmp_path =
282                                         kmalloc(MAX_TREE_SIZE + MAX_PATHCONF + 1,
283                                                 GFP_KERNEL);
284                                 if (tmp_path) {
285                                         strncpy(tmp_path, pTcon->treeName, MAX_TREE_SIZE);
286                                         strncat(tmp_path, full_path, MAX_PATHCONF);
287                                         rc = get_dfs_path(xid, pTcon->ses, tmp_path,
288                                                 cifs_sb->local_nls,
289                                                 &num_referrals, &referrals,
290                                                 cifs_sb->mnt_cifs_flags &
291                                                     CIFS_MOUNT_MAP_SPECIAL_CHR);
292                                         cFYI(1,("Get DFS for %s rc = %d ",tmp_path, rc));
293                                         if((num_referrals == 0) && (rc == 0))
294                                                 rc = -EACCES;
295                                         else {
296                                                 cFYI(1,("num referral: %d",num_referrals));
297                                                 if(referrals) {
298                                                         cFYI(1,("referral string: %s ",referrals));
299                                                         strncpy(tmpbuffer, referrals, len-1);                            
300                                                 }
301                                         }
302                                         kfree(referrals);
303                                         kfree(tmp_path);
304 }
305                                 /* BB add code like else decode referrals then memcpy to
306                                   tmpbuffer and free referrals string array BB */
307                         }
308                 }
309         }
310         /* BB Anything else to do to handle recursive links? */
311         /* BB Should we be using page ops here? */
312
313         /* BB null terminate returned string in pBuffer? BB */
314         if (rc == 0) {
315                 rc = vfs_readlink(direntry, pBuffer, len, tmpbuffer);
316                 cFYI(1,
317                      ("vfs_readlink called from cifs_readlink returned %d",
318                       rc));
319         }
320
321         kfree(tmpbuffer);
322         kfree(full_path);
323         FreeXid(xid);
324         return rc;
325 }
326
327 void cifs_put_link(struct dentry *direntry, struct nameidata *nd, void *cookie)
328 {
329         char *p = nd_get_link(nd);
330         if (!IS_ERR(p))
331                 kfree(p);
332 }