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