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);
  53         toName = build_path_from_dentry(direntry);
  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         else {
  64                 rc = CIFSCreateHardLink(xid, pTcon, fromName, toName,
  65                                         cifs_sb_target->local_nls);
  66                 if(rc == -EIO)
  67                         rc = -EOPNOTSUPP;
  68         }
  69
  70 /* if (!rc)     */
  71         {
  72                 /*   renew_parental_timestamps(old_file);
  73                    inode->i_nlink++;
  74                    mark_inode_dirty(inode);
  75                    d_instantiate(direntry, inode); */
  76                 /* BB add call to either mark inode dirty or refresh its data and timestamp to current time */
  77         }
  78         d_drop(direntry);       /* force new lookup from server */
  79         cifsInode = CIFS_I(old_file->d_inode);
  80         cifsInode->time = 0;    /* will force revalidate to go get info when needed */
  81
  82 cifs_hl_exit:
  83         if (fromName)
  84                 kfree(fromName);
  85         if (toName)
  86                 kfree(toName);
  87         FreeXid(xid);
  88         return rc;
  89 }
  90
  91 int
  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         down(&direntry->d_sb->s_vfs_rename_sem);
 105         full_path = build_path_from_dentry(direntry);
 106         up(&direntry->d_sb->s_vfs_rename_sem);
 107
 108         if (!full_path)
 109                 goto out_no_free;
 110
 111         cFYI(1, ("Full path: %s inode = 0x%p", full_path, inode));
 112         cifs_sb = CIFS_SB(inode->i_sb);
 113         pTcon = cifs_sb->tcon;
 114         target_path = kmalloc(PATH_MAX, GFP_KERNEL);
 115         if (!target_path) {
 116                 target_path = ERR_PTR(-ENOMEM);
 117                 goto out;
 118         }
 119
 120 /* BB add read reparse point symlink code and Unix extensions symlink code here BB */
 121         if (pTcon->ses->capabilities & CAP_UNIX)
 122                 rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
 123                                              target_path,
 124                                              PATH_MAX-1,
 125                                              cifs_sb->local_nls);
 126         else {
 127                 /* rc = CIFSSMBQueryReparseLinkInfo */
 128                 /* BB Add code to Query ReparsePoint info */
 129                 /* BB Add MAC style xsymlink check here if enabled */
 130         }
 131
 132         if (rc == 0) {
 133
 134 /* BB Add special case check for Samba DFS symlinks */
 135
 136                 target_path[PATH_MAX-1] = 0;
 137         } else {
 138                 kfree(target_path);
 139                 target_path = ERR_PTR(rc);
 140         }
 141
 142 out:
 143         kfree(full_path);
 144 out_no_free:
 145         FreeXid(xid);
 146         nd_set_link(nd, target_path);
 147         return 0;
 148 }
 149
 150 int
 151 cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
 152 {
 153         int rc = -EOPNOTSUPP;
 154         int xid;
 155         struct cifs_sb_info *cifs_sb;
 156         struct cifsTconInfo *pTcon;
 157         char *full_path = NULL;
 158         struct inode *newinode = NULL;
 159
 160         xid = GetXid();
 161
 162         cifs_sb = CIFS_SB(inode->i_sb);
 163         pTcon = cifs_sb->tcon;
 164
 165         down(&inode->i_sb->s_vfs_rename_sem);
 166         full_path = build_path_from_dentry(direntry);
 167         up(&inode->i_sb->s_vfs_rename_sem);
 168
 169         if(full_path == NULL) {
 170                 FreeXid(xid);
 171                 return -ENOMEM;
 172         }
 173
 174         cFYI(1, ("Full path: %s ", full_path));
 175         cFYI(1, ("symname is %s", symname));
 176
 177         /* BB what if DFS and this volume is on different share? BB */
 178         if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
 179                 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
 180                                            cifs_sb->local_nls);
 181         /* else
 182            rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,cifs_sb_target->local_nls); */
 183
 184         if (rc == 0) {
 185                 if (pTcon->ses->capabilities & CAP_UNIX)
 186                         rc = cifs_get_inode_info_unix(&newinode, full_path,
 187                                                       inode->i_sb,xid);
 188                 else
 189                         rc = cifs_get_inode_info(&newinode, full_path, NULL,
 190                                                  inode->i_sb,xid);
 191
 192                 if (rc != 0) {
 193                         cFYI(1,
 194                              ("Create symlink worked but get_inode_info failed with rc = %d ",
 195                               rc));
 196                 } else {
 197                         direntry->d_op = &cifs_dentry_ops;
 198                         d_instantiate(direntry, newinode);
 199                 }
 200         }
 201
 202         if (full_path)
 203                 kfree(full_path);
 204         FreeXid(xid);
 205         return rc;
 206 }
 207
 208 int
 209 cifs_readlink(struct dentry *direntry, char __user *pBuffer, int buflen)
 210 {
 211         struct inode *inode = direntry->d_inode;
 212         int rc = -EACCES;
 213         int xid;
 214         int oplock = FALSE;
 215         struct cifs_sb_info *cifs_sb;
 216         struct cifsTconInfo *pTcon;
 217         char *full_path = NULL;
 218         char *tmp_path =  NULL;
 219         char * tmpbuffer;
 220         unsigned char * referrals = NULL;
 221         int num_referrals = 0;
 222         int len;
 223         __u16 fid;
 224
 225         xid = GetXid();
 226         cifs_sb = CIFS_SB(inode->i_sb);
 227         pTcon = cifs_sb->tcon;
 228
 229 /* BB would it be safe against deadlock to grab this sem
 230       even though rename itself grabs the sem and calls lookup? */
 231 /*       down(&inode->i_sb->s_vfs_rename_sem);*/
 232         full_path = build_path_from_dentry(direntry);
 233 /*       up(&inode->i_sb->s_vfs_rename_sem);*/
 234
 235         if(full_path == NULL) {
 236                 FreeXid(xid);
 237                 return -ENOMEM;
 238         }
 239
 240         cFYI(1,
 241              ("Full path: %s inode = 0x%p pBuffer = 0x%p buflen = %d",
 242               full_path, inode, pBuffer, buflen));
 243         if(buflen > PATH_MAX)
 244                 len = PATH_MAX;
 245         else
 246                 len = buflen;
 247         tmpbuffer = kmalloc(len,GFP_KERNEL);
 248         if(tmpbuffer == NULL) {
 249                 if (full_path)
 250                         kfree(full_path);
 251                 FreeXid(xid);
 252                 return -ENOMEM;
 253         }
 254
 255 /* BB add read reparse point symlink code and Unix extensions symlink code here BB */
 256         if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
 257                 rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
 258                                 tmpbuffer,
 259                                 len - 1,
 260                                 cifs_sb->local_nls);
 261         else {
 262                 rc = CIFSSMBOpen(xid, pTcon, full_path, FILE_OPEN, GENERIC_READ,
 263                                 OPEN_REPARSE_POINT,&fid, &oplock, NULL, cifs_sb->local_nls);
 264                 if(!rc) {
 265                         rc = CIFSSMBQueryReparseLinkInfo(xid, pTcon, full_path,
 266                                 tmpbuffer,
 267                                 len - 1,
 268                                 fid,
 269                                 cifs_sb->local_nls);
 270                         if(CIFSSMBClose(xid, pTcon, fid)) {
 271                                 cFYI(1,("Error closing junction point (open for ioctl)"));
 272                         }
 273                         if(rc == -EIO) {
 274                                 /* Query if DFS Junction */
 275                                 tmp_path =
 276                                         kmalloc(MAX_TREE_SIZE + MAX_PATHCONF + 1,
 277                                                 GFP_KERNEL);
 278                                 if (tmp_path) {
 279                                         strncpy(tmp_path, pTcon->treeName, MAX_TREE_SIZE);
 280                                         strncat(tmp_path, full_path, MAX_PATHCONF);
 281                                         rc = get_dfs_path(xid, pTcon->ses, tmp_path,
 282                                                 cifs_sb->local_nls, &num_referrals, &referrals);
 283                                         cFYI(1,("Get DFS for %s rc = %d ",tmp_path, rc));
 284                                         if((num_referrals == 0) && (rc == 0))
 285                                                 rc = -EACCES;
 286                                         else {
 287                                                 cFYI(1,("num referral: %d",num_referrals));
 288                                                 if(referrals) {
 289                                                         cFYI(1,("referral string: %s ",referrals));
 290                                                         strncpy(tmpbuffer, referrals, len-1);
 291                                                 }
 292                                         }
 293                                         if(referrals)
 294                                                 kfree(referrals);
 295                                         kfree(tmp_path);
 296 }
 297                                 /* BB add code like else decode referrals then memcpy to
 298                                   tmpbuffer and free referrals string array BB */
 299                         }
 300                 }
 301         }
 302         /* BB Anything else to do to handle recursive links? */
 303         /* BB Should we be using page ops here? */
 304
 305         /* BB null terminate returned string in pBuffer? BB */
 306         if (rc == 0) {
 307                 rc = vfs_readlink(direntry, pBuffer, len, tmpbuffer);
 308                 cFYI(1,
 309                      ("vfs_readlink called from cifs_readlink returned %d",
 310                       rc));
 311         }
 312
 313         if (tmpbuffer) {
 314                 kfree(tmpbuffer);
 315         }
 316         if (full_path) {
 317                 kfree(full_path);
 318         }
 319         FreeXid(xid);
 320         return rc;
 321 }
 322
 323 void cifs_put_link(struct dentry *direntry, struct nameidata *nd)
 324 {
 325         char *p = nd_get_link(nd);
 326         if (!IS_ERR(p))
 327                 kfree(p);
 328 }