[CIFS] POSIX extensions, SetFSInfo added
[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, cifs_sb_target);
53         toName = build_path_from_dentry(direntry, cifs_sb_target);
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         cifs_sb = CIFS_SB(inode->i_sb);
109         pTcon = cifs_sb->tcon;
110
111         down(&direntry->d_sb->s_vfs_rename_sem);
112         full_path = build_path_from_dentry(direntry, cifs_sb);
113         up(&direntry->d_sb->s_vfs_rename_sem);
114
115         if (!full_path)
116                 goto out_no_free;
117
118         cFYI(1, ("Full path: %s inode = 0x%p", full_path, inode));
119         target_path = kmalloc(PATH_MAX, GFP_KERNEL);
120         if (!target_path) {
121                 target_path = ERR_PTR(-ENOMEM);
122                 goto out;
123         }
124
125 /* BB add read reparse point symlink code and Unix extensions symlink code here BB */
126         if (pTcon->ses->capabilities & CAP_UNIX)
127                 rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
128                                              target_path,
129                                              PATH_MAX-1,
130                                              cifs_sb->local_nls);
131         else {
132                 /* rc = CIFSSMBQueryReparseLinkInfo */
133                 /* BB Add code to Query ReparsePoint info */
134                 /* BB Add MAC style xsymlink check here if enabled */
135         }
136
137         if (rc == 0) {
138
139 /* BB Add special case check for Samba DFS symlinks */
140
141                 target_path[PATH_MAX-1] = 0;
142         } else {
143                 kfree(target_path);
144                 target_path = ERR_PTR(rc);
145         }
146
147 out:
148         kfree(full_path);
149 out_no_free:
150         FreeXid(xid);
151         nd_set_link(nd, target_path);
152         return 0;
153 }
154
155 int
156 cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
157 {
158         int rc = -EOPNOTSUPP;
159         int xid;
160         struct cifs_sb_info *cifs_sb;
161         struct cifsTconInfo *pTcon;
162         char *full_path = NULL;
163         struct inode *newinode = NULL;
164
165         xid = GetXid();
166
167         cifs_sb = CIFS_SB(inode->i_sb);
168         pTcon = cifs_sb->tcon;
169
170         down(&inode->i_sb->s_vfs_rename_sem);
171         full_path = build_path_from_dentry(direntry, cifs_sb);
172         up(&inode->i_sb->s_vfs_rename_sem);
173
174         if(full_path == NULL) {
175                 FreeXid(xid);
176                 return -ENOMEM;
177         }
178
179         cFYI(1, ("Full path: %s ", full_path));
180         cFYI(1, ("symname is %s", symname));
181
182         /* BB what if DFS and this volume is on different share? BB */
183         if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
184                 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
185                                            cifs_sb->local_nls);
186         /* else
187            rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,cifs_sb_target->local_nls); */
188
189         if (rc == 0) {
190                 if (pTcon->ses->capabilities & CAP_UNIX)
191                         rc = cifs_get_inode_info_unix(&newinode, full_path,
192                                                       inode->i_sb,xid);
193                 else
194                         rc = cifs_get_inode_info(&newinode, full_path, NULL,
195                                                  inode->i_sb,xid);
196
197                 if (rc != 0) {
198                         cFYI(1,
199                              ("Create symlink worked but get_inode_info failed with rc = %d ",
200                               rc));
201                 } else {
202                         direntry->d_op = &cifs_dentry_ops;
203                         d_instantiate(direntry, newinode);
204                 }
205         }
206
207         if (full_path)
208                 kfree(full_path);
209         FreeXid(xid);
210         return rc;
211 }
212
213 int
214 cifs_readlink(struct dentry *direntry, char __user *pBuffer, int buflen)
215 {
216         struct inode *inode = direntry->d_inode;
217         int rc = -EACCES;
218         int xid;
219         int oplock = FALSE;
220         struct cifs_sb_info *cifs_sb;
221         struct cifsTconInfo *pTcon;
222         char *full_path = NULL;
223         char *tmp_path =  NULL;
224         char * tmpbuffer;
225         unsigned char * referrals = NULL;
226         int num_referrals = 0;
227         int len;
228         __u16 fid;
229
230         xid = GetXid();
231         cifs_sb = CIFS_SB(inode->i_sb);
232         pTcon = cifs_sb->tcon;
233
234 /* BB would it be safe against deadlock to grab this sem 
235       even though rename itself grabs the sem and calls lookup? */
236 /*       down(&inode->i_sb->s_vfs_rename_sem);*/
237         full_path = build_path_from_dentry(direntry, cifs_sb);
238 /*       up(&inode->i_sb->s_vfs_rename_sem);*/
239
240         if(full_path == NULL) {
241                 FreeXid(xid);
242                 return -ENOMEM;
243         }
244
245         cFYI(1,
246              ("Full path: %s inode = 0x%p pBuffer = 0x%p buflen = %d",
247               full_path, inode, pBuffer, buflen));
248         if(buflen > PATH_MAX)
249                 len = PATH_MAX;
250         else
251                 len = buflen;
252         tmpbuffer = kmalloc(len,GFP_KERNEL);   
253         if(tmpbuffer == NULL) {
254                 if (full_path)
255                         kfree(full_path);
256                 FreeXid(xid);
257                 return -ENOMEM;
258         }
259
260 /* BB add read reparse point symlink code and Unix extensions symlink code here BB */
261         if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
262                 rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
263                                 tmpbuffer,
264                                 len - 1,
265                                 cifs_sb->local_nls);
266         else {
267                 rc = CIFSSMBOpen(xid, pTcon, full_path, FILE_OPEN, GENERIC_READ,
268                                 OPEN_REPARSE_POINT,&fid, &oplock, NULL, 
269                                 cifs_sb->local_nls, 
270                                 cifs_sb->mnt_cifs_flags & 
271                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
272                 if(!rc) {
273                         rc = CIFSSMBQueryReparseLinkInfo(xid, pTcon, full_path,
274                                 tmpbuffer,
275                                 len - 1, 
276                                 fid,
277                                 cifs_sb->local_nls);
278                         if(CIFSSMBClose(xid, pTcon, fid)) {
279                                 cFYI(1,("Error closing junction point (open for ioctl)"));
280                         }
281                         if(rc == -EIO) {
282                                 /* Query if DFS Junction */
283                                 tmp_path =
284                                         kmalloc(MAX_TREE_SIZE + MAX_PATHCONF + 1,
285                                                 GFP_KERNEL);
286                                 if (tmp_path) {
287                                         strncpy(tmp_path, pTcon->treeName, MAX_TREE_SIZE);
288                                         strncat(tmp_path, full_path, MAX_PATHCONF);
289                                         rc = get_dfs_path(xid, pTcon->ses, tmp_path,
290                                                 cifs_sb->local_nls,
291                                                 &num_referrals, &referrals,
292                                                 cifs_sb->mnt_cifs_flags &
293                                                     CIFS_MOUNT_MAP_SPECIAL_CHR);
294                                         cFYI(1,("Get DFS for %s rc = %d ",tmp_path, rc));
295                                         if((num_referrals == 0) && (rc == 0))
296                                                 rc = -EACCES;
297                                         else {
298                                                 cFYI(1,("num referral: %d",num_referrals));
299                                                 if(referrals) {
300                                                         cFYI(1,("referral string: %s ",referrals));
301                                                         strncpy(tmpbuffer, referrals, len-1);                            
302                                                 }
303                                         }
304                                         if(referrals)
305                                                 kfree(referrals);
306                                         kfree(tmp_path);
307 }
308                                 /* BB add code like else decode referrals then memcpy to
309                                   tmpbuffer and free referrals string array BB */
310                         }
311                 }
312         }
313         /* BB Anything else to do to handle recursive links? */
314         /* BB Should we be using page ops here? */
315
316         /* BB null terminate returned string in pBuffer? BB */
317         if (rc == 0) {
318                 rc = vfs_readlink(direntry, pBuffer, len, tmpbuffer);
319                 cFYI(1,
320                      ("vfs_readlink called from cifs_readlink returned %d",
321                       rc));
322         }
323
324         if (tmpbuffer) {
325                 kfree(tmpbuffer);
326         }
327         if (full_path) {
328                 kfree(full_path);
329         }
330         FreeXid(xid);
331         return rc;
332 }
333
334 void cifs_put_link(struct dentry *direntry, struct nameidata *nd)
335 {
336         char *p = nd_get_link(nd);
337         if (!IS_ERR(p))
338                 kfree(p);
339 }