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