fs/cifs/dir.c

   1 /*
   2  *   fs/cifs/dir.c
   3  *
   4  *   vfs operations that deal with dentries
   5  *
   6  *   Copyright (C) International Business Machines  Corp., 2002,2003
   7  *   Author(s): Steve French (sfrench@us.ibm.com)
   8  *
   9  *   This library is free software; you can redistribute it and/or modify
  10  *   it under the terms of the GNU Lesser General Public License as published
  11  *   by the Free Software Foundation; either version 2.1 of the License, or
  12  *   (at your option) any later version.
  13  *
  14  *   This library is distributed in the hope that it will be useful,
  15  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  17  *   the GNU Lesser General Public License for more details.
  18  *
  19  *   You should have received a copy of the GNU Lesser General Public License
  20  *   along with this library; if not, write to the Free Software
  21  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  */
  23 #include <linux/fs.h>
  24 #include <linux/stat.h>
  25 #include <linux/slab.h>
  26 #include <linux/namei.h>
  27 #include "cifsfs.h"
  28 #include "cifspdu.h"
  29 #include "cifsglob.h"
  30 #include "cifsproto.h"
  31 #include "cifs_debug.h"
  32 #include "cifs_fs_sb.h"
  33
  34 void
  35 renew_parental_timestamps(struct dentry *direntry)
  36 {
  37         /* BB check if there is a way to get the kernel to do this or if we really need this */
  38         do {
  39                 direntry->d_time = jiffies;
  40                 direntry = direntry->d_parent;
  41         } while (!IS_ROOT(direntry));
  42 }
  43
  44 /* Note: caller must free return buffer */
  45 char *
  46 build_path_from_dentry(struct dentry *direntry)
  47 {
  48         struct dentry *temp;
  49         int namelen = 0;
  50         char *full_path;
  51
  52         if(direntry == NULL)
  53                 return NULL;  /* not much we can do if dentry is freed and
  54                 we need to reopen the file after it was closed implicitly
  55                 when the server crashed */
  56
  57 cifs_bp_rename_retry:
  58         for (temp = direntry; !IS_ROOT(temp);) {
  59                 namelen += (1 + temp->d_name.len);
  60                 temp = temp->d_parent;
  61                 if(temp == NULL) {
  62                         cERROR(1,("corrupt dentry"));
  63                         return NULL;
  64                 }
  65         }
  66
  67         full_path = kmalloc(namelen+1, GFP_KERNEL);
  68         if(full_path == NULL)
  69                 return full_path;
  70         full_path[namelen] = 0; /* trailing null */
  71
  72         for (temp = direntry; !IS_ROOT(temp);) {
  73                 namelen -= 1 + temp->d_name.len;
  74                 if (namelen < 0) {
  75                         break;
  76                 } else {
  77                         full_path[namelen] = '\\';
  78                         strncpy(full_path + namelen + 1, temp->d_name.name,
  79                                 temp->d_name.len);
  80                         cFYI(0, (" name: %s ", full_path + namelen));
  81                 }
  82                 temp = temp->d_parent;
  83                 if(temp == NULL) {
  84                         cERROR(1,("corrupt dentry"));
  85                         kfree(full_path);
  86                         return NULL;
  87                 }
  88         }
  89         if (namelen != 0) {
  90                 cERROR(1,
  91                        ("We did not end path lookup where we expected namelen is %d",
  92                         namelen));
  93                 /* presumably this is only possible if we were racing with a rename
  94                 of one of the parent directories  (we can not lock the dentries
  95                 above us to prevent this, but retrying should be harmless) */
  96                 kfree(full_path);
  97                 namelen = 0;
  98                 goto cifs_bp_rename_retry;
  99         }
 100
 101         return full_path;
 102 }
 103
 104 /* char * build_wildcard_path_from_dentry(struct dentry *direntry)
 105 {
 106         if(full_path == NULL)
 107                 return full_path;
 108
 109         full_path[namelen] = '\\';
 110         full_path[namelen+1] = '*';
 111         full_path[namelen+2] = 0;
 112 BB remove above eight lines BB */
 113
 114 /* Inode operations in similar order to how they appear in the Linux file fs.h */
 115
 116 int
 117 cifs_create(struct inode *inode, struct dentry *direntry, int mode,
 118                 struct nameidata *nd)
 119 {
 120         int rc = -ENOENT;
 121         int xid;
 122         int oplock = 0;
 123         int desiredAccess = GENERIC_READ | GENERIC_WRITE;
 124         __u16 fileHandle;
 125         struct cifs_sb_info *cifs_sb;
 126         struct cifsTconInfo *pTcon;
 127         char *full_path = NULL;
 128         FILE_ALL_INFO * buf = NULL;
 129         struct inode *newinode = NULL;
 130         struct cifsFileInfo * pCifsFile = NULL;
 131         struct cifsInodeInfo * pCifsInode;
 132         int disposition = FILE_OVERWRITE_IF;
 133         int write_only = FALSE;
 134
 135         xid = GetXid();
 136
 137         cifs_sb = CIFS_SB(inode->i_sb);
 138         pTcon = cifs_sb->tcon;
 139
 140         down(&direntry->d_sb->s_vfs_rename_sem);
 141         full_path = build_path_from_dentry(direntry);
 142         up(&direntry->d_sb->s_vfs_rename_sem);
 143         if(full_path == NULL) {
 144                 FreeXid(xid);
 145                 return -ENOMEM;
 146         }
 147
 148         if(nd) {
 149                 if ((nd->intent.open.flags & O_ACCMODE) == O_RDONLY)
 150                         desiredAccess = GENERIC_READ;
 151                 else if ((nd->intent.open.flags & O_ACCMODE) == O_WRONLY) {
 152                         desiredAccess = GENERIC_WRITE;
 153                         write_only = TRUE;
 154                 } else if ((nd->intent.open.flags & O_ACCMODE) == O_RDWR) {
 155                         /* GENERIC_ALL is too much permission to request */
 156                         /* can cause unnecessary access denied on create */
 157                         /* desiredAccess = GENERIC_ALL; */
 158                         desiredAccess = GENERIC_READ | GENERIC_WRITE;
 159                 }
 160
 161                 if((nd->intent.open.flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 162                         disposition = FILE_CREATE;
 163                 else if((nd->intent.open.flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
 164                         disposition = FILE_OVERWRITE_IF;
 165                 else if((nd->intent.open.flags & O_CREAT) == O_CREAT)
 166                         disposition = FILE_OPEN_IF;
 167                 else {
 168                         cFYI(1,("Create flag not set in create function"));
 169                 }
 170         }
 171
 172         /* BB add processing to set equivalent of mode - e.g. via CreateX with ACLs */
 173         if (oplockEnabled)
 174                 oplock = REQ_OPLOCK;
 175
 176         buf = kmalloc(sizeof(FILE_ALL_INFO),GFP_KERNEL);
 177         if(buf == NULL) {
 178                 kfree(full_path);
 179                 FreeXid(xid);
 180                 return -ENOMEM;
 181         }
 182
 183         rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
 184                          desiredAccess, CREATE_NOT_DIR,
 185                          &fileHandle, &oplock, buf, cifs_sb->local_nls,
 186                          cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 187         if (rc) {
 188                 cFYI(1, ("cifs_create returned 0x%x ", rc));
 189         } else {
 190                 /* If Open reported that we actually created a file
 191                 then we now have to set the mode if possible */
 192                 if ((cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
 193                         (oplock & CIFS_CREATE_ACTION))
 194                         if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 195                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
 196                                         (__u64)current->euid,
 197                                         (__u64)current->egid,
 198                                         0 /* dev */,
 199                                         cifs_sb->local_nls,
 200                                         cifs_sb->mnt_cifs_flags &
 201                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 202                         } else {
 203                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
 204                                         (__u64)-1,
 205                                         (__u64)-1,
 206                                         0 /* dev */,
 207                                         cifs_sb->local_nls,
 208                                         cifs_sb->mnt_cifs_flags &
 209                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 210                         }
 211                 else {
 212                         /* BB implement via Windows security descriptors */
 213                         /* eg CIFSSMBWinSetPerms(xid,pTcon,full_path,mode,-1,-1,local_nls);*/
 214                         /* could set r/o dos attribute if mode & 0222 == 0 */
 215                 }
 216
 217         /* BB server might mask mode so we have to query for Unix case*/
 218                 if (pTcon->ses->capabilities & CAP_UNIX)
 219                         rc = cifs_get_inode_info_unix(&newinode, full_path,
 220                                                  inode->i_sb,xid);
 221                 else {
 222                         rc = cifs_get_inode_info(&newinode, full_path,
 223                                                  buf, inode->i_sb,xid);
 224                         if(newinode)
 225                                 newinode->i_mode = mode;
 226                 }
 227
 228                 if (rc != 0) {
 229                         cFYI(1,("Create worked but get_inode_info failed with rc = %d",
 230                               rc));
 231                 } else {
 232                         direntry->d_op = &cifs_dentry_ops;
 233                         d_instantiate(direntry, newinode);
 234                 }
 235                 if((nd->flags & LOOKUP_OPEN) == FALSE) {
 236                         /* mknod case - do not leave file open */
 237                         CIFSSMBClose(xid, pTcon, fileHandle);
 238                 } else if(newinode) {
 239                         pCifsFile =
 240                            kmalloc(sizeof (struct cifsFileInfo), GFP_KERNEL);
 241
 242                         if(pCifsFile == NULL)
 243                                 goto cifs_create_out;
 244                         memset((char *)pCifsFile, 0,
 245                                sizeof (struct cifsFileInfo));
 246                         pCifsFile->netfid = fileHandle;
 247                         pCifsFile->pid = current->tgid;
 248                         pCifsFile->pInode = newinode;
 249                         pCifsFile->invalidHandle = FALSE;
 250                         pCifsFile->closePend     = FALSE;
 251                         init_MUTEX(&pCifsFile->fh_sem);
 252                         /* set the following in open now
 253                                 pCifsFile->pfile = file; */
 254                         write_lock(&GlobalSMBSeslock);
 255                         list_add(&pCifsFile->tlist,&pTcon->openFileList);
 256                         pCifsInode = CIFS_I(newinode);
 257                         if(pCifsInode) {
 258                                 /* if readable file instance put first in list*/
 259                                 if (write_only == TRUE) {
 260                                         list_add_tail(&pCifsFile->flist,
 261                                                 &pCifsInode->openFileList);
 262                                 } else {
 263                                         list_add(&pCifsFile->flist,
 264                                                 &pCifsInode->openFileList);
 265                                 }
 266                                 if((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
 267                                         pCifsInode->clientCanCacheAll = TRUE;
 268                                         pCifsInode->clientCanCacheRead = TRUE;
 269                                         cFYI(1,("Exclusive Oplock for inode %p",
 270                                                 newinode));
 271                                 } else if((oplock & 0xF) == OPLOCK_READ)
 272                                         pCifsInode->clientCanCacheRead = TRUE;
 273                         }
 274                         write_unlock(&GlobalSMBSeslock);
 275                 }
 276         }
 277 cifs_create_out:
 278         kfree(buf);
 279         kfree(full_path);
 280         FreeXid(xid);
 281         return rc;
 282 }
 283
 284 int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode, dev_t device_number)
 285 {
 286         int rc = -EPERM;
 287         int xid;
 288         struct cifs_sb_info *cifs_sb;
 289         struct cifsTconInfo *pTcon;
 290         char *full_path = NULL;
 291         struct inode * newinode = NULL;
 292
 293         if (!old_valid_dev(device_number))
 294                 return -EINVAL;
 295
 296         xid = GetXid();
 297
 298         cifs_sb = CIFS_SB(inode->i_sb);
 299         pTcon = cifs_sb->tcon;
 300
 301         down(&direntry->d_sb->s_vfs_rename_sem);
 302         full_path = build_path_from_dentry(direntry);
 303         up(&direntry->d_sb->s_vfs_rename_sem);
 304         if(full_path == NULL)
 305                 rc = -ENOMEM;
 306
 307         if (full_path && (pTcon->ses->capabilities & CAP_UNIX)) {
 308                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 309                         rc = CIFSSMBUnixSetPerms(xid, pTcon, full_path,
 310                                 mode,(__u64)current->euid,(__u64)current->egid,
 311                                 device_number, cifs_sb->local_nls,
 312                                 cifs_sb->mnt_cifs_flags &
 313                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 314                 } else {
 315                         rc = CIFSSMBUnixSetPerms(xid, pTcon,
 316                                 full_path, mode, (__u64)-1, (__u64)-1,
 317                                 device_number, cifs_sb->local_nls,
 318                                 cifs_sb->mnt_cifs_flags &
 319                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 320                 }
 321
 322                 if(!rc) {
 323                         rc = cifs_get_inode_info_unix(&newinode, full_path,
 324                                                 inode->i_sb,xid);
 325                         direntry->d_op = &cifs_dentry_ops;
 326                         if(rc == 0)
 327                                 d_instantiate(direntry, newinode);
 328                 }
 329         }
 330
 331         kfree(full_path);
 332         FreeXid(xid);
 333         return rc;
 334 }
 335
 336
 337 struct dentry *
 338 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, struct nameidata *nd)
 339 {
 340         int xid;
 341         int rc = 0; /* to get around spurious gcc warning, set to zero here */
 342         struct cifs_sb_info *cifs_sb;
 343         struct cifsTconInfo *pTcon;
 344         struct inode *newInode = NULL;
 345         char *full_path = NULL;
 346
 347         xid = GetXid();
 348
 349         cFYI(1,
 350              (" parent inode = 0x%p name is: %s and dentry = 0x%p",
 351               parent_dir_inode, direntry->d_name.name, direntry));
 352
 353         /* BB Add check of incoming data - e.g. frame not longer than maximum SMB - let server check the namelen BB */
 354
 355         /* check whether path exists */
 356
 357         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
 358         pTcon = cifs_sb->tcon;
 359
 360         /* can not grab the rename sem here since it would
 361         deadlock in the cases (beginning of sys_rename itself)
 362         in which we already have the sb rename sem */
 363         full_path = build_path_from_dentry(direntry);
 364         if(full_path == NULL) {
 365                 FreeXid(xid);
 366                 return ERR_PTR(-ENOMEM);
 367         }
 368
 369         if (direntry->d_inode != NULL) {
 370                 cFYI(1, (" non-NULL inode in lookup"));
 371         } else {
 372                 cFYI(1, (" NULL inode in lookup"));
 373         }
 374         cFYI(1,
 375              (" Full path: %s inode = 0x%p", full_path, direntry->d_inode));
 376
 377         if (pTcon->ses->capabilities & CAP_UNIX)
 378                 rc = cifs_get_inode_info_unix(&newInode, full_path,
 379                                               parent_dir_inode->i_sb,xid);
 380         else
 381                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
 382                                          parent_dir_inode->i_sb,xid);
 383
 384         if ((rc == 0) && (newInode != NULL)) {
 385                 direntry->d_op = &cifs_dentry_ops;
 386                 d_add(direntry, newInode);
 387
 388                 /* since paths are not looked up by component - the parent directories are presumed to be good here */
 389                 renew_parental_timestamps(direntry);
 390
 391         } else if (rc == -ENOENT) {
 392                 rc = 0;
 393                 d_add(direntry, NULL);
 394         } else {
 395                 cERROR(1,("Error 0x%x or on cifs_get_inode_info in lookup",rc));
 396                 /* BB special case check for Access Denied - watch security
 397                 exposure of returning dir info implicitly via different rc
 398                 if file exists or not but no access BB */
 399         }
 400
 401         kfree(full_path);
 402         FreeXid(xid);
 403         return ERR_PTR(rc);
 404 }
 405
 406 static int
 407 cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
 408 {
 409         int isValid = 1;
 410
 411 /*      lock_kernel(); *//* surely we do not want to lock the kernel for a whole network round trip which could take seconds */
 412
 413         if (direntry->d_inode) {
 414                 if (cifs_revalidate(direntry)) {
 415                         /* unlock_kernel(); */
 416                         return 0;
 417                 }
 418         } else {
 419                 cFYI(1,
 420                      ("In cifs_d_revalidate with no inode but name = %s and dentry 0x%p",
 421                       direntry->d_name.name, direntry));
 422         }
 423
 424 /*    unlock_kernel(); */
 425
 426         return isValid;
 427 }
 428
 429 /* static int cifs_d_delete(struct dentry *direntry)
 430 {
 431         int rc = 0;
 432
 433         cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));
 434
 435         return rc;
 436 }     */
 437
 438 struct dentry_operations cifs_dentry_ops = {
 439         .d_revalidate = cifs_d_revalidate,
 440 /* d_delete:       cifs_d_delete,       *//* not needed except for debugging */
 441         /* no need for d_hash, d_compare, d_release, d_iput ... yet. BB confirm this BB */
 442 };