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 "cifsfs.h"
  24 #include "cifspdu.h"
  25 #include "cifsglob.h"
  26 #include "cifsproto.h"
  27 #include "cifs_debug.h"
  28 #include "cifs_fs_sb.h"
  29
  30 int
  31 cifs_hardlink(struct dentry *old_file, struct inode *inode,
  32               struct dentry *direntry)
  33 {
  34         int rc = -EACCES;
  35         int xid;
  36         char *fromName = NULL;
  37         char *toName = NULL;
  38         struct cifs_sb_info *cifs_sb_target;
  39         struct cifsTconInfo *pTcon;
  40         struct cifsInodeInfo *cifsInode;
  41
  42         xid = GetXid();
  43
  44         cifs_sb_target = CIFS_SB(inode->i_sb);
  45         pTcon = cifs_sb_target->tcon;
  46
  47 /* No need to check for cross device links since server will do that - BB note DFS case in future though (when we may have to check) */
  48
  49         fromName = build_path_from_dentry(old_file);
  50         toName = build_path_from_dentry(direntry);
  51         if (cifs_sb_target->tcon->ses->capabilities & CAP_UNIX)
  52                 rc = CIFSUnixCreateHardLink(xid, pTcon, fromName, toName,
  53                                             cifs_sb_target->local_nls);
  54         else {
  55                 rc = CIFSCreateHardLink(xid, pTcon, fromName, toName,
  56                                         cifs_sb_target->local_nls);
  57                 if(rc == -EIO)
  58                         rc = -EOPNOTSUPP;
  59         }
  60
  61 /* if (!rc)     */
  62         {
  63                 /*   renew_parental_timestamps(old_file);
  64                    inode->i_nlink++;
  65                    mark_inode_dirty(inode);
  66                    d_instantiate(direntry, inode); */
  67                 /* BB add call to either mark inode dirty or refresh its data and timestamp to current time */
  68         }
  69         d_drop(direntry);       /* force new lookup from server */
  70         cifsInode = CIFS_I(old_file->d_inode);
  71         cifsInode->time = 0;    /* will force revalidate to go get info when needed */
  72
  73         if (fromName)
  74                 kfree(fromName);
  75         if (toName)
  76                 kfree(toName);
  77         FreeXid(xid);
  78         return rc;
  79 }
  80
  81 int
  82 cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
  83 {
  84         struct inode *inode = direntry->d_inode;
  85         int rc = -EACCES;
  86         int xid;
  87         char *full_path = NULL;
  88         char * target_path;
  89         struct cifs_sb_info *cifs_sb;
  90         struct cifsTconInfo *pTcon;
  91
  92         xid = GetXid();
  93         full_path = build_path_from_dentry(direntry);
  94         cFYI(1, ("Full path: %s inode = 0x%p", full_path, inode));
  95         cifs_sb = CIFS_SB(inode->i_sb);
  96         pTcon = cifs_sb->tcon;
  97         target_path = kmalloc(PATH_MAX, GFP_KERNEL);
  98         if(target_path == NULL) {
  99                 if (full_path)
 100                         kfree(full_path);
 101                 FreeXid(xid);
 102                 return -ENOMEM;
 103         }
 104         /* can not call the following line due to EFAULT in vfs_readlink which is presumably expecting a user space buffer */
 105         /* length = cifs_readlink(direntry,target_path, sizeof(target_path) - 1);    */
 106
 107 /* BB add read reparse point symlink code and Unix extensions symlink code here BB */
 108         if (pTcon->ses->capabilities & CAP_UNIX)
 109                 rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
 110                                              target_path,
 111                                              PATH_MAX-1,
 112                                              cifs_sb->local_nls);
 113         else {
 114                 /* rc = CIFSSMBQueryReparseLinkInfo */
 115                 /* BB Add code to Query ReparsePoint info */
 116         }
 117         /* BB Anything else to do to handle recursive links? */
 118         /* BB Should we be using page symlink ops here? */
 119
 120         if (rc == 0) {
 121
 122 /* BB Add special case check for Samba DFS symlinks */
 123
 124                 target_path[PATH_MAX-1] = 0;
 125                 rc = vfs_follow_link(nd, target_path);
 126         }
 127         /* else EACCESS */
 128
 129         if (target_path)
 130                 kfree(target_path);
 131         if (full_path)
 132                 kfree(full_path);
 133         FreeXid(xid);
 134         return rc;
 135 }
 136
 137 int
 138 cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
 139 {
 140         int rc = -EOPNOTSUPP;
 141         int xid;
 142         struct cifs_sb_info *cifs_sb;
 143         struct cifsTconInfo *pTcon;
 144         char *full_path = NULL;
 145         struct inode *newinode = NULL;
 146
 147         xid = GetXid();
 148
 149         cifs_sb = CIFS_SB(inode->i_sb);
 150         pTcon = cifs_sb->tcon;
 151
 152         full_path = build_path_from_dentry(direntry);
 153         cFYI(1, ("Full path: %s ", full_path));
 154         cFYI(1, ("symname is %s", symname));
 155
 156         /* BB what if DFS and this volume is on different share? BB */
 157         if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
 158                 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
 159                                            cifs_sb->local_nls);
 160         /* else
 161            rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,cifs_sb_target->local_nls); */
 162
 163         if (rc == 0) {
 164                 if (pTcon->ses->capabilities & CAP_UNIX)
 165                         rc = cifs_get_inode_info_unix(&newinode, full_path,
 166                                                       inode->i_sb);
 167                 else
 168                         rc = cifs_get_inode_info(&newinode, full_path, NULL,
 169                                                  inode->i_sb);
 170
 171                 if (rc != 0) {
 172                         cFYI(1,
 173                              ("Create symlink worked but get_inode_info failed with rc = %d ",
 174                               rc));
 175                 } else {
 176                         direntry->d_op = &cifs_dentry_ops;
 177                         d_instantiate(direntry, newinode);
 178                 }
 179         }
 180
 181         if (full_path)
 182                 kfree(full_path);
 183         FreeXid(xid);
 184         return rc;
 185 }
 186
 187 int
 188 cifs_readlink(struct dentry *direntry, char *pBuffer, int buflen)
 189 {
 190         struct inode *inode = direntry->d_inode;
 191         int rc = -EACCES;
 192         int xid;
 193         int oplock = FALSE;
 194         struct cifs_sb_info *cifs_sb;
 195         struct cifsTconInfo *pTcon;
 196         char *full_path = NULL;
 197         char *tmp_path =  NULL;
 198         char * tmpbuffer;
 199         unsigned char * referrals = NULL;
 200         int num_referrals = 0;
 201         int len;
 202         __u16 fid;
 203
 204         xid = GetXid();
 205         cifs_sb = CIFS_SB(inode->i_sb);
 206         pTcon = cifs_sb->tcon;
 207         full_path = build_path_from_dentry(direntry);
 208         cFYI(1,
 209              ("Full path: %s inode = 0x%p pBuffer = 0x%p buflen = %d",
 210               full_path, inode, pBuffer, buflen));
 211         if(buflen > PATH_MAX)
 212                 len = PATH_MAX;
 213         else
 214                 len = buflen;
 215         tmpbuffer = kmalloc(len,GFP_KERNEL);
 216         if(tmpbuffer == NULL) {
 217                 if (full_path)
 218                         kfree(full_path);
 219                 FreeXid(xid);
 220                 return -ENOMEM;
 221         }
 222
 223 /* BB add read reparse point symlink code and Unix extensions symlink code here BB */
 224         if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
 225                 rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
 226                                 tmpbuffer,
 227                                 len - 1,
 228                                 cifs_sb->local_nls);
 229         else {
 230                 rc = CIFSSMBOpen(xid, pTcon, full_path, FILE_OPEN, GENERIC_READ,
 231                                 OPEN_REPARSE_POINT,&fid, &oplock, NULL, cifs_sb->local_nls);
 232                 if(!rc) {
 233                         rc = CIFSSMBQueryReparseLinkInfo(xid, pTcon, full_path,
 234                                 tmpbuffer,
 235                                 len - 1,
 236                                 fid,
 237                                 cifs_sb->local_nls);
 238                         if(CIFSSMBClose(xid, pTcon, fid)) {
 239                                 cFYI(1,("Error closing junction point (open for ioctl)"));
 240                         }
 241                         if(rc == -EIO) {
 242                                 /* Query if DFS Junction */
 243                                 tmp_path =
 244                                         kmalloc(MAX_TREE_SIZE + MAX_PATHCONF + 1,
 245                                                 GFP_KERNEL);
 246                                 if (tmp_path) {
 247                                         strncpy(tmp_path, pTcon->treeName, MAX_TREE_SIZE);
 248                                         strncat(tmp_path, full_path, MAX_PATHCONF);
 249                                         rc = get_dfs_path(xid, pTcon->ses, tmp_path,
 250                                                 cifs_sb->local_nls, &num_referrals, &referrals);
 251                                         cFYI(1,("Get DFS for %s rc = %d ",tmp_path, rc));
 252                                         if((num_referrals == 0) && (rc == 0))
 253                                                 rc = -EACCES;
 254                                         else {
 255                                                 cFYI(1,("num referral: %d",num_referrals));
 256                                                 if(referrals) {
 257                                                         cFYI(1,("referral string: %s ",referrals));
 258                                                         strncpy(tmpbuffer, referrals, len-1);
 259                                                 }
 260                                         }
 261                                         if(referrals)
 262                                                 kfree(referrals);
 263                                         kfree(tmp_path);
 264                                         if(referrals) {
 265                                                 kfree(referrals);
 266                                         }
 267                                 }
 268                                 /* BB add code like else decode referrals then memcpy to
 269                                   tmpbuffer and free referrals string array BB */
 270                         }
 271                 }
 272         }
 273         /* BB Anything else to do to handle recursive links? */
 274         /* BB Should we be using page ops here? */
 275
 276         /* BB null terminate returned string in pBuffer? BB */
 277         if (rc == 0) {
 278                 rc = vfs_readlink(direntry, pBuffer, len, tmpbuffer);
 279                 cFYI(1,
 280                      ("vfs_readlink called from cifs_readlink returned %d",
 281                       rc));
 282         }
 283
 284         if (tmpbuffer) {
 285                 kfree(tmpbuffer);
 286         }
 287         if (full_path) {
 288                 kfree(full_path);
 289         }
 290         FreeXid(xid);
 291         return rc;
 292 }