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