Pull thermal into release branch
[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         d_drop(direntry);       /* force new lookup from server of target */
73
74         /* if source file is cached (oplocked) revalidate will not go to server
75            until the file is closed or oplock broken so update nlinks locally */
76         if(old_file->d_inode) {
77                 cifsInode = CIFS_I(old_file->d_inode);
78                 if(rc == 0) {
79                         old_file->d_inode->i_nlink++;
80 /* BB should we make this contingent on superblock flag NOATIME? */
81 /*                      old_file->d_inode->i_ctime = CURRENT_TIME;*/
82                         /* parent dir timestamps will update from srv
83                         within a second, would it really be worth it
84                         to set the parent dir cifs inode time to zero
85                         to force revalidate (faster) for it too? */
86                 }
87                 /* if not oplocked will force revalidate to get info 
88                    on source file from srv */
89                 cifsInode->time = 0;
90
91                 /* Will update parent dir timestamps from srv within a second.
92                    Would it really be worth it to set the parent dir (cifs
93                    inode) time field to zero to force revalidate on parent
94                    directory faster ie 
95                         CIFS_I(inode)->time = 0;  */
96         }
97
98 cifs_hl_exit:
99         kfree(fromName);
100         kfree(toName);
101         FreeXid(xid);
102         return rc;
103 }
104
105 void *
106 cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
107 {
108         struct inode *inode = direntry->d_inode;
109         int rc = -EACCES;
110         int xid;
111         char *full_path = NULL;
112         char * target_path = ERR_PTR(-ENOMEM);
113         struct cifs_sb_info *cifs_sb;
114         struct cifsTconInfo *pTcon;
115
116         xid = GetXid();
117
118         full_path = build_path_from_dentry(direntry);
119
120         if (!full_path)
121                 goto out_no_free;
122
123         cFYI(1, ("Full path: %s inode = 0x%p", full_path, inode));
124         cifs_sb = CIFS_SB(inode->i_sb);
125         pTcon = cifs_sb->tcon;
126         target_path = kmalloc(PATH_MAX, GFP_KERNEL);
127         if (!target_path) {
128                 target_path = ERR_PTR(-ENOMEM);
129                 goto out;
130         }
131
132 /* BB add read reparse point symlink code and Unix extensions symlink code here BB */
133         if (pTcon->ses->capabilities & CAP_UNIX)
134                 rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
135                                              target_path,
136                                              PATH_MAX-1,
137                                              cifs_sb->local_nls);
138         else {
139                 /* rc = CIFSSMBQueryReparseLinkInfo */
140                 /* BB Add code to Query ReparsePoint info */
141                 /* BB Add MAC style xsymlink check here if enabled */
142         }
143
144         if (rc == 0) {
145
146 /* BB Add special case check for Samba DFS symlinks */
147
148                 target_path[PATH_MAX-1] = 0;
149         } else {
150                 kfree(target_path);
151                 target_path = ERR_PTR(rc);
152         }
153
154 out:
155         kfree(full_path);
156 out_no_free:
157         FreeXid(xid);
158         nd_set_link(nd, target_path);
159         return NULL;    /* No cookie */
160 }
161
162 int
163 cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
164 {
165         int rc = -EOPNOTSUPP;
166         int xid;
167         struct cifs_sb_info *cifs_sb;
168         struct cifsTconInfo *pTcon;
169         char *full_path = NULL;
170         struct inode *newinode = NULL;
171
172         xid = GetXid();
173
174         cifs_sb = CIFS_SB(inode->i_sb);
175         pTcon = cifs_sb->tcon;
176
177         full_path = build_path_from_dentry(direntry);
178
179         if(full_path == NULL) {
180                 FreeXid(xid);
181                 return -ENOMEM;
182         }
183
184         cFYI(1, ("Full path: %s", full_path));
185         cFYI(1, ("symname is %s", symname));
186
187         /* BB what if DFS and this volume is on different share? BB */
188         if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
189                 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
190                                            cifs_sb->local_nls);
191         /* else
192            rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,cifs_sb_target->local_nls); */
193
194         if (rc == 0) {
195                 if (pTcon->ses->capabilities & CAP_UNIX)
196                         rc = cifs_get_inode_info_unix(&newinode, full_path,
197                                                       inode->i_sb,xid);
198                 else
199                         rc = cifs_get_inode_info(&newinode, full_path, NULL,
200                                                  inode->i_sb,xid);
201
202                 if (rc != 0) {
203                         cFYI(1, ("Create symlink ok, getinodeinfo fail rc = %d",
204                               rc));
205                 } else {
206                         if (pTcon->nocase)
207                                 direntry->d_op = &cifs_ci_dentry_ops;
208                         else
209                                 direntry->d_op = &cifs_dentry_ops;
210                         d_instantiate(direntry, newinode);
211                 }
212         }
213
214         kfree(full_path);
215         FreeXid(xid);
216         return rc;
217 }
218
219 int
220 cifs_readlink(struct dentry *direntry, char __user *pBuffer, int buflen)
221 {
222         struct inode *inode = direntry->d_inode;
223         int rc = -EACCES;
224         int xid;
225         int oplock = FALSE;
226         struct cifs_sb_info *cifs_sb;
227         struct cifsTconInfo *pTcon;
228         char *full_path = NULL;
229         char *tmp_path =  NULL;
230         char * tmpbuffer;
231         unsigned char * referrals = NULL;
232         int num_referrals = 0;
233         int len;
234         __u16 fid;
235
236         xid = GetXid();
237         cifs_sb = CIFS_SB(inode->i_sb);
238         pTcon = cifs_sb->tcon;
239
240 /* BB would it be safe against deadlock to grab this sem 
241       even though rename itself grabs the sem and calls lookup? */
242 /*       mutex_lock(&inode->i_sb->s_vfs_rename_mutex);*/
243         full_path = build_path_from_dentry(direntry);
244 /*       mutex_unlock(&inode->i_sb->s_vfs_rename_mutex);*/
245
246         if(full_path == NULL) {
247                 FreeXid(xid);
248                 return -ENOMEM;
249         }
250
251         cFYI(1,
252              ("Full path: %s inode = 0x%p pBuffer = 0x%p buflen = %d",
253               full_path, inode, pBuffer, buflen));
254         if(buflen > PATH_MAX)
255                 len = PATH_MAX;
256         else
257                 len = buflen;
258         tmpbuffer = kmalloc(len,GFP_KERNEL);   
259         if(tmpbuffer == NULL) {
260                 kfree(full_path);
261                 FreeXid(xid);
262                 return -ENOMEM;
263         }
264
265 /* BB add read reparse point symlink code and Unix extensions symlink code here BB */
266         if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
267                 rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
268                                 tmpbuffer,
269                                 len - 1,
270                                 cifs_sb->local_nls);
271         else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
272                 cERROR(1,("SFU style symlinks not implemented yet"));
273                 /* add open and read as in fs/cifs/inode.c */
274         
275         } else {
276                 rc = CIFSSMBOpen(xid, pTcon, full_path, FILE_OPEN, GENERIC_READ,
277                                 OPEN_REPARSE_POINT,&fid, &oplock, NULL, 
278                                 cifs_sb->local_nls, 
279                                 cifs_sb->mnt_cifs_flags & 
280                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
281                 if(!rc) {
282                         rc = CIFSSMBQueryReparseLinkInfo(xid, pTcon, full_path,
283                                 tmpbuffer,
284                                 len - 1, 
285                                 fid,
286                                 cifs_sb->local_nls);
287                         if(CIFSSMBClose(xid, pTcon, fid)) {
288                                 cFYI(1,("Error closing junction point (open for ioctl)"));
289                         }
290                         if(rc == -EIO) {
291                                 /* Query if DFS Junction */
292                                 tmp_path =
293                                         kmalloc(MAX_TREE_SIZE + MAX_PATHCONF + 1,
294                                                 GFP_KERNEL);
295                                 if (tmp_path) {
296                                         strncpy(tmp_path, pTcon->treeName, MAX_TREE_SIZE);
297                                         strncat(tmp_path, full_path, MAX_PATHCONF);
298                                         rc = get_dfs_path(xid, pTcon->ses, tmp_path,
299                                                 cifs_sb->local_nls,
300                                                 &num_referrals, &referrals,
301                                                 cifs_sb->mnt_cifs_flags &
302                                                     CIFS_MOUNT_MAP_SPECIAL_CHR);
303                                         cFYI(1,("Get DFS for %s rc = %d ",tmp_path, rc));
304                                         if((num_referrals == 0) && (rc == 0))
305                                                 rc = -EACCES;
306                                         else {
307                                                 cFYI(1,("num referral: %d",num_referrals));
308                                                 if(referrals) {
309                                                         cFYI(1,("referral string: %s",referrals));
310                                                         strncpy(tmpbuffer, referrals, len-1);                            
311                                                 }
312                                         }
313                                         kfree(referrals);
314                                         kfree(tmp_path);
315 }
316                                 /* BB add code like else decode referrals then memcpy to
317                                   tmpbuffer and free referrals string array BB */
318                         }
319                 }
320         }
321         /* BB Anything else to do to handle recursive links? */
322         /* BB Should we be using page ops here? */
323
324         /* BB null terminate returned string in pBuffer? BB */
325         if (rc == 0) {
326                 rc = vfs_readlink(direntry, pBuffer, len, tmpbuffer);
327                 cFYI(1,
328                      ("vfs_readlink called from cifs_readlink returned %d",
329                       rc));
330         }
331
332         kfree(tmpbuffer);
333         kfree(full_path);
334         FreeXid(xid);
335         return rc;
336 }
337
338 void cifs_put_link(struct dentry *direntry, struct nameidata *nd, void *cookie)
339 {
340         char *p = nd_get_link(nd);
341         if (!IS_ERR(p))
342                 kfree(p);
343 }