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 /* Note: caller must free return buffer */
 105 char *
 106 build_wildcard_path_from_dentry(struct dentry *direntry)
 107 {
 108         struct dentry *temp;
 109         int namelen = 0;
 110         char *full_path;
 111
 112         if(direntry == NULL)
 113                 return NULL;  /* not much we can do if dentry is freed and
 114                 we need to reopen the file after it was closed implicitly
 115                 when the server crashed */
 116
 117 cifs_bwp_rename_retry:
 118         for (temp = direntry; !IS_ROOT(temp);) {
 119                 namelen += (1 + temp->d_name.len);
 120                 temp = temp->d_parent;
 121                 if(temp == NULL) {
 122                         cERROR(1,("corrupt dentry"));
 123                         return NULL;
 124                 }
 125         }
 126
 127         full_path = kmalloc(namelen+3, GFP_KERNEL);
 128         if(full_path == NULL)
 129                 return full_path;
 130
 131         full_path[namelen] = '\\';
 132         full_path[namelen+1] = '*';
 133         full_path[namelen+2] = 0;  /* trailing null */
 134
 135         for (temp = direntry; !IS_ROOT(temp);) {
 136                 namelen -= 1 + temp->d_name.len;
 137                 if (namelen < 0) {
 138                         break;
 139                 } else {
 140                         full_path[namelen] = '\\';
 141                         strncpy(full_path + namelen + 1, temp->d_name.name,
 142                                 temp->d_name.len);
 143                         cFYI(0, (" name: %s ", full_path + namelen));
 144                 }
 145                 temp = temp->d_parent;
 146                 if(temp == NULL) {
 147                         cERROR(1,("corrupt dentry"));
 148                         kfree(full_path);
 149                         return NULL;
 150                 }
 151         }
 152         if (namelen != 0) {
 153                 cERROR(1,
 154                        ("We did not end path lookup where we expected namelen is %d",
 155                         namelen));
 156                 /* presumably this is only possible if we were racing with a rename
 157                 of one of the parent directories  (we can not lock the dentries
 158                 above us to prevent this, but retrying should be harmless) */
 159                 kfree(full_path);
 160                 namelen = 0;
 161                 goto cifs_bwp_rename_retry;
 162         }
 163
 164         return full_path;
 165 }
 166
 167 /* Inode operations in similar order to how they appear in the Linux file fs.h */
 168
 169 int
 170 cifs_create(struct inode *inode, struct dentry *direntry, int mode,
 171                 struct nameidata *nd)
 172 {
 173         int rc = -ENOENT;
 174         int xid;
 175         int oplock = 0;
 176         int desiredAccess = GENERIC_READ | GENERIC_WRITE;
 177         __u16 fileHandle;
 178         struct cifs_sb_info *cifs_sb;
 179         struct cifsTconInfo *pTcon;
 180         char *full_path = NULL;
 181         FILE_ALL_INFO * buf = NULL;
 182         struct inode *newinode = NULL;
 183         struct cifsFileInfo * pCifsFile = NULL;
 184         struct cifsInodeInfo * pCifsInode;
 185         int disposition = FILE_OVERWRITE_IF;
 186         int write_only = FALSE;
 187
 188         xid = GetXid();
 189
 190         cifs_sb = CIFS_SB(inode->i_sb);
 191         pTcon = cifs_sb->tcon;
 192
 193         down(&direntry->d_sb->s_vfs_rename_sem);
 194         full_path = build_path_from_dentry(direntry);
 195         up(&direntry->d_sb->s_vfs_rename_sem);
 196         if(full_path == NULL) {
 197                 FreeXid(xid);
 198                 return -ENOMEM;
 199         }
 200
 201         if(nd) {
 202                 if ((nd->intent.open.flags & O_ACCMODE) == O_RDONLY)
 203                         desiredAccess = GENERIC_READ;
 204                 else if ((nd->intent.open.flags & O_ACCMODE) == O_WRONLY) {
 205                         desiredAccess = GENERIC_WRITE;
 206                         write_only = TRUE;
 207                 } else if ((nd->intent.open.flags & O_ACCMODE) == O_RDWR) {
 208                         /* GENERIC_ALL is too much permission to request */
 209                         /* can cause unnecessary access denied on create */
 210                         /* desiredAccess = GENERIC_ALL; */
 211                         desiredAccess = GENERIC_READ | GENERIC_WRITE;
 212                 }
 213
 214                 if((nd->intent.open.flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 215                         disposition = FILE_CREATE;
 216                 else if((nd->intent.open.flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
 217                         disposition = FILE_OVERWRITE_IF;
 218                 else if((nd->intent.open.flags & O_CREAT) == O_CREAT)
 219                         disposition = FILE_OPEN_IF;
 220                 else {
 221                         cFYI(1,("Create flag not set in create function"));
 222                 }
 223         }
 224
 225         /* BB add processing to set equivalent of mode - e.g. via CreateX with ACLs */
 226         if (oplockEnabled)
 227                 oplock = REQ_OPLOCK;
 228
 229         buf = kmalloc(sizeof(FILE_ALL_INFO),GFP_KERNEL);
 230         if(buf == NULL) {
 231                 kfree(full_path);
 232                 FreeXid(xid);
 233                 return -ENOMEM;
 234         }
 235
 236         rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
 237                          desiredAccess, CREATE_NOT_DIR,
 238                          &fileHandle, &oplock, buf, cifs_sb->local_nls);
 239         if (rc) {
 240                 cFYI(1, ("cifs_create returned 0x%x ", rc));
 241         } else {
 242                 /* If Open reported that we actually created a file
 243                 then we now have to set the mode if possible */
 244                 if ((cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
 245                         (oplock & CIFS_CREATE_ACTION))
 246                         if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 247                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
 248                                         (__u64)current->euid,
 249                                         (__u64)current->egid,
 250                                         0 /* dev */,
 251                                         cifs_sb->local_nls);
 252                         } else {
 253                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
 254                                         (__u64)-1,
 255                                         (__u64)-1,
 256                                         0 /* dev */,
 257                                         cifs_sb->local_nls);
 258                         }
 259                 else {
 260                         /* BB implement via Windows security descriptors */
 261                         /* eg CIFSSMBWinSetPerms(xid,pTcon,full_path,mode,-1,-1,local_nls);*/
 262                         /* could set r/o dos attribute if mode & 0222 == 0 */
 263                 }
 264
 265         /* BB server might mask mode so we have to query for Unix case*/
 266                 if (pTcon->ses->capabilities & CAP_UNIX)
 267                         rc = cifs_get_inode_info_unix(&newinode, full_path,
 268                                                  inode->i_sb,xid);
 269                 else {
 270                         rc = cifs_get_inode_info(&newinode, full_path,
 271                                                  buf, inode->i_sb,xid);
 272                         if(newinode)
 273                                 newinode->i_mode = mode;
 274                 }
 275
 276                 if (rc != 0) {
 277                         cFYI(1,("Create worked but get_inode_info failed with rc = %d",
 278                               rc));
 279                 } else {
 280                         direntry->d_op = &cifs_dentry_ops;
 281                         d_instantiate(direntry, newinode);
 282                 }
 283                 if((nd->flags & LOOKUP_OPEN) == FALSE) {
 284                         /* mknod case - do not leave file open */
 285                         CIFSSMBClose(xid, pTcon, fileHandle);
 286                 } else if(newinode) {
 287                         pCifsFile =
 288                            kmalloc(sizeof (struct cifsFileInfo), GFP_KERNEL);
 289
 290                         if(pCifsFile == NULL)
 291                                 goto cifs_create_out;
 292                         memset((char *)pCifsFile, 0,
 293                                sizeof (struct cifsFileInfo));
 294                         pCifsFile->netfid = fileHandle;
 295                         pCifsFile->pid = current->tgid;
 296                         pCifsFile->pInode = newinode;
 297                         pCifsFile->invalidHandle = FALSE;
 298                         pCifsFile->closePend     = FALSE;
 299                         init_MUTEX(&pCifsFile->fh_sem);
 300                         /* set the following in open now
 301                                 pCifsFile->pfile = file; */
 302                         write_lock(&GlobalSMBSeslock);
 303                         list_add(&pCifsFile->tlist,&pTcon->openFileList);
 304                         pCifsInode = CIFS_I(newinode);
 305                         if(pCifsInode) {
 306                                 /* if readable file instance put first in list*/
 307                                 if (write_only == TRUE) {
 308                                         list_add_tail(&pCifsFile->flist,
 309                                                 &pCifsInode->openFileList);
 310                                 } else {
 311                                         list_add(&pCifsFile->flist,
 312                                                 &pCifsInode->openFileList);
 313                                 }
 314                                 if((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
 315                                         pCifsInode->clientCanCacheAll = TRUE;
 316                                         pCifsInode->clientCanCacheRead = TRUE;
 317                                         cFYI(1,("Exclusive Oplock for inode %p",
 318                                                 newinode));
 319                                 } else if((oplock & 0xF) == OPLOCK_READ)
 320                                         pCifsInode->clientCanCacheRead = TRUE;
 321                         }
 322                         write_unlock(&GlobalSMBSeslock);
 323                 }
 324         }
 325 cifs_create_out:
 326         kfree(buf);
 327         kfree(full_path);
 328         FreeXid(xid);
 329         return rc;
 330 }
 331
 332 int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode, dev_t device_number)
 333 {
 334         int rc = -EPERM;
 335         int xid;
 336         struct cifs_sb_info *cifs_sb;
 337         struct cifsTconInfo *pTcon;
 338         char *full_path = NULL;
 339         struct inode * newinode = NULL;
 340
 341         if (!old_valid_dev(device_number))
 342                 return -EINVAL;
 343
 344         xid = GetXid();
 345
 346         cifs_sb = CIFS_SB(inode->i_sb);
 347         pTcon = cifs_sb->tcon;
 348
 349         down(&direntry->d_sb->s_vfs_rename_sem);
 350         full_path = build_path_from_dentry(direntry);
 351         up(&direntry->d_sb->s_vfs_rename_sem);
 352         if(full_path == NULL)
 353                 rc = -ENOMEM;
 354
 355         if (full_path && (pTcon->ses->capabilities & CAP_UNIX)) {
 356                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 357                         rc = CIFSSMBUnixSetPerms(xid, pTcon, full_path,
 358                                 mode,(__u64)current->euid,(__u64)current->egid,
 359                                 device_number, cifs_sb->local_nls);
 360                 } else {
 361                         rc = CIFSSMBUnixSetPerms(xid, pTcon,
 362                                 full_path, mode, (__u64)-1, (__u64)-1,
 363                                 device_number, cifs_sb->local_nls);
 364                 }
 365
 366                 if(!rc) {
 367                         rc = cifs_get_inode_info_unix(&newinode, full_path,
 368                                                 inode->i_sb,xid);
 369                         direntry->d_op = &cifs_dentry_ops;
 370                         if(rc == 0)
 371                                 d_instantiate(direntry, newinode);
 372                 }
 373         }
 374
 375         kfree(full_path);
 376         FreeXid(xid);
 377         return rc;
 378 }
 379
 380
 381 struct dentry *
 382 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, struct nameidata *nd)
 383 {
 384         int xid;
 385         int rc = 0; /* to get around spurious gcc warning, set to zero here */
 386         struct cifs_sb_info *cifs_sb;
 387         struct cifsTconInfo *pTcon;
 388         struct inode *newInode = NULL;
 389         char *full_path = NULL;
 390
 391         xid = GetXid();
 392
 393         cFYI(1,
 394              (" parent inode = 0x%p name is: %s and dentry = 0x%p",
 395               parent_dir_inode, direntry->d_name.name, direntry));
 396
 397         /* BB Add check of incoming data - e.g. frame not longer than maximum SMB - let server check the namelen BB */
 398
 399         /* check whether path exists */
 400
 401         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
 402         pTcon = cifs_sb->tcon;
 403
 404         /* can not grab the rename sem here since it would
 405         deadlock in the cases (beginning of sys_rename itself)
 406         in which we already have the sb rename sem */
 407         full_path = build_path_from_dentry(direntry);
 408         if(full_path == NULL) {
 409                 FreeXid(xid);
 410                 return ERR_PTR(-ENOMEM);
 411         }
 412
 413         if (direntry->d_inode != NULL) {
 414                 cFYI(1, (" non-NULL inode in lookup"));
 415         } else {
 416                 cFYI(1, (" NULL inode in lookup"));
 417         }
 418         cFYI(1,
 419              (" Full path: %s inode = 0x%p", full_path, direntry->d_inode));
 420
 421         if (pTcon->ses->capabilities & CAP_UNIX)
 422                 rc = cifs_get_inode_info_unix(&newInode, full_path,
 423                                               parent_dir_inode->i_sb,xid);
 424         else
 425                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
 426                                          parent_dir_inode->i_sb,xid);
 427
 428         if ((rc == 0) && (newInode != NULL)) {
 429                 direntry->d_op = &cifs_dentry_ops;
 430                 d_add(direntry, newInode);
 431
 432                 /* since paths are not looked up by component - the parent directories are presumed to be good here */
 433                 renew_parental_timestamps(direntry);
 434
 435         } else if (rc == -ENOENT) {
 436                 rc = 0;
 437                 d_add(direntry, NULL);
 438         } else {
 439                 cERROR(1,("Error 0x%x or on cifs_get_inode_info in lookup",rc));
 440                 /* BB special case check for Access Denied - watch security
 441                 exposure of returning dir info implicitly via different rc
 442                 if file exists or not but no access BB */
 443         }
 444
 445         kfree(full_path);
 446         FreeXid(xid);
 447         return ERR_PTR(rc);
 448 }
 449
 450 int
 451 cifs_dir_open(struct inode *inode, struct file *file)
 452 {                               /* NB: currently unused since searches are opened in readdir */
 453         int rc = 0;
 454         int xid;
 455         struct cifs_sb_info *cifs_sb;
 456         struct cifsTconInfo *pTcon;
 457         char *full_path = NULL;
 458
 459         xid = GetXid();
 460
 461         cifs_sb = CIFS_SB(inode->i_sb);
 462         pTcon = cifs_sb->tcon;
 463
 464         if(file->f_dentry) {
 465                 down(&file->f_dentry->d_sb->s_vfs_rename_sem);
 466                 full_path = build_wildcard_path_from_dentry(file->f_dentry);
 467                 up(&file->f_dentry->d_sb->s_vfs_rename_sem);
 468         } else {
 469                 FreeXid(xid);
 470                 return -EIO;
 471         }
 472
 473         cFYI(1, ("inode = 0x%p and full path is %s", inode, full_path));
 474
 475         kfree(full_path);
 476         FreeXid(xid);
 477         return rc;
 478 }
 479
 480 static int
 481 cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
 482 {
 483         int isValid = 1;
 484
 485 /*      lock_kernel(); *//* surely we do not want to lock the kernel for a whole network round trip which could take seconds */
 486
 487         if (direntry->d_inode) {
 488                 if (cifs_revalidate(direntry)) {
 489                         /* unlock_kernel(); */
 490                         return 0;
 491                 }
 492         } else {
 493                 cFYI(1,
 494                      ("In cifs_d_revalidate with no inode but name = %s and dentry 0x%p",
 495                       direntry->d_name.name, direntry));
 496         }
 497
 498 /*    unlock_kernel(); */
 499
 500         return isValid;
 501 }
 502
 503 /* static int cifs_d_delete(struct dentry *direntry)
 504 {
 505         int rc = 0;
 506
 507         cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));
 508
 509         return rc;
 510 }     */
 511
 512 struct dentry_operations cifs_dentry_ops = {
 513         .d_revalidate = cifs_d_revalidate,
 514 /* d_delete:       cifs_d_delete,       *//* not needed except for debugging */
 515         /* no need for d_hash, d_compare, d_release, d_iput ... yet. BB confirm this BB */
 516 };