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         char dirsep = CIFS_DIR_SEP(CIFS_SB(direntry->d_sb));
  52
  53         if(direntry == NULL)
  54                 return NULL;  /* not much we can do if dentry is freed and
  55                 we need to reopen the file after it was closed implicitly
  56                 when the server crashed */
  57
  58 cifs_bp_rename_retry:
  59         for (temp = direntry; !IS_ROOT(temp);) {
  60                 namelen += (1 + temp->d_name.len);
  61                 temp = temp->d_parent;
  62                 if(temp == NULL) {
  63                         cERROR(1,("corrupt dentry"));
  64                         return NULL;
  65                 }
  66         }
  67
  68         full_path = kmalloc(namelen+1, GFP_KERNEL);
  69         if(full_path == NULL)
  70                 return full_path;
  71         full_path[namelen] = 0; /* trailing null */
  72
  73         for (temp = direntry; !IS_ROOT(temp);) {
  74                 namelen -= 1 + temp->d_name.len;
  75                 if (namelen < 0) {
  76                         break;
  77                 } else {
  78                         full_path[namelen] = dirsep;
  79                         strncpy(full_path + namelen + 1, temp->d_name.name,
  80                                 temp->d_name.len);
  81                         cFYI(0, (" name: %s ", full_path + namelen));
  82                 }
  83                 temp = temp->d_parent;
  84                 if(temp == NULL) {
  85                         cERROR(1,("corrupt dentry"));
  86                         kfree(full_path);
  87                         return NULL;
  88                 }
  89         }
  90         if (namelen != 0) {
  91                 cERROR(1,
  92                        ("We did not end path lookup where we expected namelen is %d",
  93                         namelen));
  94                 /* presumably this is only possible if we were racing with a rename
  95                 of one of the parent directories  (we can not lock the dentries
  96                 above us to prevent this, but retrying should be harmless) */
  97                 kfree(full_path);
  98                 namelen = 0;
  99                 goto cifs_bp_rename_retry;
 100         }
 101
 102         return full_path;
 103 }
 104
 105 /* char * build_wildcard_path_from_dentry(struct dentry *direntry)
 106 {
 107         if(full_path == NULL)
 108                 return full_path;
 109
 110         full_path[namelen] = '\\';
 111         full_path[namelen+1] = '*';
 112         full_path[namelen+2] = 0;
 113 BB remove above eight lines BB */
 114
 115 /* Inode operations in similar order to how they appear in the Linux file fs.h */
 116
 117 int
 118 cifs_create(struct inode *inode, struct dentry *direntry, int mode,
 119                 struct nameidata *nd)
 120 {
 121         int rc = -ENOENT;
 122         int xid;
 123         int oplock = 0;
 124         int desiredAccess = GENERIC_READ | GENERIC_WRITE;
 125         __u16 fileHandle;
 126         struct cifs_sb_info *cifs_sb;
 127         struct cifsTconInfo *pTcon;
 128         char *full_path = NULL;
 129         FILE_ALL_INFO * buf = NULL;
 130         struct inode *newinode = NULL;
 131         struct cifsFileInfo * pCifsFile = NULL;
 132         struct cifsInodeInfo * pCifsInode;
 133         int disposition = FILE_OVERWRITE_IF;
 134         int write_only = FALSE;
 135
 136         xid = GetXid();
 137
 138         cifs_sb = CIFS_SB(inode->i_sb);
 139         pTcon = cifs_sb->tcon;
 140
 141         down(&direntry->d_sb->s_vfs_rename_sem);
 142         full_path = build_path_from_dentry(direntry);
 143         up(&direntry->d_sb->s_vfs_rename_sem);
 144         if(full_path == NULL) {
 145                 FreeXid(xid);
 146                 return -ENOMEM;
 147         }
 148
 149         if(nd && (nd->flags & LOOKUP_OPEN)) {
 150                 int oflags = nd->intent.open.flags;
 151
 152                 desiredAccess = 0;
 153                 if (oflags & FMODE_READ)
 154                         desiredAccess |= GENERIC_READ;
 155                 if (oflags & FMODE_WRITE) {
 156                         desiredAccess |= GENERIC_WRITE;
 157                         if (!(oflags & FMODE_READ))
 158                                 write_only = TRUE;
 159                 }
 160
 161                 if((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 162                         disposition = FILE_CREATE;
 163                 else if((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
 164                         disposition = FILE_OVERWRITE_IF;
 165                 else if((oflags & 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 == -EIO) {
 188                 /* old server, retry the open legacy style */
 189                 rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
 190                         desiredAccess, CREATE_NOT_DIR,
 191                         &fileHandle, &oplock, buf, cifs_sb->local_nls,
 192                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 193         }
 194         if (rc) {
 195                 cFYI(1, ("cifs_create returned 0x%x ", rc));
 196         } else {
 197                 /* If Open reported that we actually created a file
 198                 then we now have to set the mode if possible */
 199                 if ((cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
 200                         (oplock & CIFS_CREATE_ACTION))
 201                         if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 202                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
 203                                         (__u64)current->euid,
 204                                         (__u64)current->egid,
 205                                         0 /* dev */,
 206                                         cifs_sb->local_nls,
 207                                         cifs_sb->mnt_cifs_flags &
 208                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 209                         } else {
 210                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
 211                                         (__u64)-1,
 212                                         (__u64)-1,
 213                                         0 /* dev */,
 214                                         cifs_sb->local_nls,
 215                                         cifs_sb->mnt_cifs_flags &
 216                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 217                         }
 218                 else {
 219                         /* BB implement mode setting via Windows security descriptors */
 220                         /* eg CIFSSMBWinSetPerms(xid,pTcon,full_path,mode,-1,-1,local_nls);*/
 221                         /* could set r/o dos attribute if mode & 0222 == 0 */
 222                 }
 223
 224         /* BB server might mask mode so we have to query for Unix case*/
 225                 if (pTcon->ses->capabilities & CAP_UNIX)
 226                         rc = cifs_get_inode_info_unix(&newinode, full_path,
 227                                                  inode->i_sb,xid);
 228                 else {
 229                         rc = cifs_get_inode_info(&newinode, full_path,
 230                                                  buf, inode->i_sb,xid);
 231                         if(newinode)
 232                                 newinode->i_mode = mode;
 233                 }
 234
 235                 if (rc != 0) {
 236                         cFYI(1,
 237                              ("Create worked but get_inode_info failed rc = %d",
 238                               rc));
 239                 } else {
 240                         if (pTcon->nocase)
 241                                 direntry->d_op = &cifs_ci_dentry_ops;
 242                         else
 243                                 direntry->d_op = &cifs_dentry_ops;
 244                         d_instantiate(direntry, newinode);
 245                 }
 246                 if((nd->flags & LOOKUP_OPEN) == FALSE) {
 247                         /* mknod case - do not leave file open */
 248                         CIFSSMBClose(xid, pTcon, fileHandle);
 249                 } else if(newinode) {
 250                         pCifsFile =
 251                            kmalloc(sizeof (struct cifsFileInfo), GFP_KERNEL);
 252
 253                         if(pCifsFile == NULL)
 254                                 goto cifs_create_out;
 255                         memset((char *)pCifsFile, 0,
 256                                sizeof (struct cifsFileInfo));
 257                         pCifsFile->netfid = fileHandle;
 258                         pCifsFile->pid = current->tgid;
 259                         pCifsFile->pInode = newinode;
 260                         pCifsFile->invalidHandle = FALSE;
 261                         pCifsFile->closePend     = FALSE;
 262                         init_MUTEX(&pCifsFile->fh_sem);
 263                         /* set the following in open now
 264                                 pCifsFile->pfile = file; */
 265                         write_lock(&GlobalSMBSeslock);
 266                         list_add(&pCifsFile->tlist,&pTcon->openFileList);
 267                         pCifsInode = CIFS_I(newinode);
 268                         if(pCifsInode) {
 269                                 /* if readable file instance put first in list*/
 270                                 if (write_only == TRUE) {
 271                                         list_add_tail(&pCifsFile->flist,
 272                                                 &pCifsInode->openFileList);
 273                                 } else {
 274                                         list_add(&pCifsFile->flist,
 275                                                 &pCifsInode->openFileList);
 276                                 }
 277                                 if((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
 278                                         pCifsInode->clientCanCacheAll = TRUE;
 279                                         pCifsInode->clientCanCacheRead = TRUE;
 280                                         cFYI(1,("Exclusive Oplock for inode %p",
 281                                                 newinode));
 282                                 } else if((oplock & 0xF) == OPLOCK_READ)
 283                                         pCifsInode->clientCanCacheRead = TRUE;
 284                         }
 285                         write_unlock(&GlobalSMBSeslock);
 286                 }
 287         }
 288 cifs_create_out:
 289         kfree(buf);
 290         kfree(full_path);
 291         FreeXid(xid);
 292         return rc;
 293 }
 294
 295 int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode, dev_t device_number)
 296 {
 297         int rc = -EPERM;
 298         int xid;
 299         struct cifs_sb_info *cifs_sb;
 300         struct cifsTconInfo *pTcon;
 301         char *full_path = NULL;
 302         struct inode * newinode = NULL;
 303
 304         if (!old_valid_dev(device_number))
 305                 return -EINVAL;
 306
 307         xid = GetXid();
 308
 309         cifs_sb = CIFS_SB(inode->i_sb);
 310         pTcon = cifs_sb->tcon;
 311
 312         down(&direntry->d_sb->s_vfs_rename_sem);
 313         full_path = build_path_from_dentry(direntry);
 314         up(&direntry->d_sb->s_vfs_rename_sem);
 315         if(full_path == NULL)
 316                 rc = -ENOMEM;
 317         else if (pTcon->ses->capabilities & CAP_UNIX) {
 318                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 319                         rc = CIFSSMBUnixSetPerms(xid, pTcon, full_path,
 320                                 mode,(__u64)current->euid,(__u64)current->egid,
 321                                 device_number, cifs_sb->local_nls,
 322                                 cifs_sb->mnt_cifs_flags &
 323                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 324                 } else {
 325                         rc = CIFSSMBUnixSetPerms(xid, pTcon,
 326                                 full_path, mode, (__u64)-1, (__u64)-1,
 327                                 device_number, cifs_sb->local_nls,
 328                                 cifs_sb->mnt_cifs_flags &
 329                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 330                 }
 331
 332                 if(!rc) {
 333                         rc = cifs_get_inode_info_unix(&newinode, full_path,
 334                                                 inode->i_sb,xid);
 335                         if (pTcon->nocase)
 336                                 direntry->d_op = &cifs_ci_dentry_ops;
 337                         else
 338                                 direntry->d_op = &cifs_dentry_ops;
 339                         if(rc == 0)
 340                                 d_instantiate(direntry, newinode);
 341                 }
 342         } else {
 343                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
 344                         int oplock = 0;
 345                         u16 fileHandle;
 346                         FILE_ALL_INFO * buf;
 347
 348                         cFYI(1,("sfu compat create special file"));
 349
 350                         buf = kmalloc(sizeof(FILE_ALL_INFO),GFP_KERNEL);
 351                         if(buf == NULL) {
 352                                 kfree(full_path);
 353                                 FreeXid(xid);
 354                                 return -ENOMEM;
 355                         }
 356
 357                         rc = CIFSSMBOpen(xid, pTcon, full_path,
 358                                          FILE_CREATE, /* fail if exists */
 359                                          GENERIC_WRITE /* BB would
 360                                           WRITE_OWNER | WRITE_DAC be better? */,
 361                                          /* Create a file and set the
 362                                             file attribute to SYSTEM */
 363                                          CREATE_NOT_DIR | CREATE_OPTION_SPECIAL,
 364                                          &fileHandle, &oplock, buf,
 365                                          cifs_sb->local_nls,
 366                                          cifs_sb->mnt_cifs_flags &
 367                                             CIFS_MOUNT_MAP_SPECIAL_CHR);
 368
 369                         if(!rc) {
 370                                 /* BB Do not bother to decode buf since no
 371                                    local inode yet to put timestamps in */
 372                                 CIFSSMBClose(xid, pTcon, fileHandle);
 373                                 d_drop(direntry);
 374                         }
 375                         kfree(buf);
 376                         /* add code here to set EAs */
 377                 }
 378         }
 379
 380         kfree(full_path);
 381         FreeXid(xid);
 382         return rc;
 383 }
 384
 385
 386 struct dentry *
 387 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, struct nameidata *nd)
 388 {
 389         int xid;
 390         int rc = 0; /* to get around spurious gcc warning, set to zero here */
 391         struct cifs_sb_info *cifs_sb;
 392         struct cifsTconInfo *pTcon;
 393         struct inode *newInode = NULL;
 394         char *full_path = NULL;
 395
 396         xid = GetXid();
 397
 398         cFYI(1,
 399              (" parent inode = 0x%p name is: %s and dentry = 0x%p",
 400               parent_dir_inode, direntry->d_name.name, direntry));
 401
 402         /* BB Add check of incoming data - e.g. frame not longer than maximum SMB - let server check the namelen BB */
 403
 404         /* check whether path exists */
 405
 406         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
 407         pTcon = cifs_sb->tcon;
 408
 409         /* can not grab the rename sem here since it would
 410         deadlock in the cases (beginning of sys_rename itself)
 411         in which we already have the sb rename sem */
 412         full_path = build_path_from_dentry(direntry);
 413         if(full_path == NULL) {
 414                 FreeXid(xid);
 415                 return ERR_PTR(-ENOMEM);
 416         }
 417
 418         if (direntry->d_inode != NULL) {
 419                 cFYI(1, (" non-NULL inode in lookup"));
 420         } else {
 421                 cFYI(1, (" NULL inode in lookup"));
 422         }
 423         cFYI(1,
 424              (" Full path: %s inode = 0x%p", full_path, direntry->d_inode));
 425
 426         if (pTcon->ses->capabilities & CAP_UNIX)
 427                 rc = cifs_get_inode_info_unix(&newInode, full_path,
 428                                               parent_dir_inode->i_sb,xid);
 429         else
 430                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
 431                                          parent_dir_inode->i_sb,xid);
 432
 433         if ((rc == 0) && (newInode != NULL)) {
 434                 if (pTcon->nocase)
 435                         direntry->d_op = &cifs_ci_dentry_ops;
 436                 else
 437                         direntry->d_op = &cifs_dentry_ops;
 438                 d_add(direntry, newInode);
 439
 440                 /* since paths are not looked up by component - the parent directories are presumed to be good here */
 441                 renew_parental_timestamps(direntry);
 442
 443         } else if (rc == -ENOENT) {
 444                 rc = 0;
 445                 d_add(direntry, NULL);
 446         } else {
 447                 cERROR(1,("Error 0x%x on cifs_get_inode_info in lookup of %s",
 448                            rc,full_path));
 449                 /* BB special case check for Access Denied - watch security
 450                 exposure of returning dir info implicitly via different rc
 451                 if file exists or not but no access BB */
 452         }
 453
 454         kfree(full_path);
 455         FreeXid(xid);
 456         return ERR_PTR(rc);
 457 }
 458
 459 static int
 460 cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
 461 {
 462         int isValid = 1;
 463
 464 /*      lock_kernel(); *//* surely we do not want to lock the kernel for a whole network round trip which could take seconds */
 465
 466         if (direntry->d_inode) {
 467                 if (cifs_revalidate(direntry)) {
 468                         /* unlock_kernel(); */
 469                         return 0;
 470                 }
 471         } else {
 472                 cFYI(1,
 473                      ("In cifs_d_revalidate with no inode but name = %s and dentry 0x%p",
 474                       direntry->d_name.name, direntry));
 475         }
 476
 477 /*    unlock_kernel(); */
 478
 479         return isValid;
 480 }
 481
 482 /* static int cifs_d_delete(struct dentry *direntry)
 483 {
 484         int rc = 0;
 485
 486         cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));
 487
 488         return rc;
 489 }     */
 490
 491 struct dentry_operations cifs_dentry_ops = {
 492         .d_revalidate = cifs_d_revalidate,
 493 /* d_delete:       cifs_d_delete,       *//* not needed except for debugging */
 494         /* no need for d_hash, d_compare, d_release, d_iput ... yet. BB confirm this BB */
 495 };
 496
 497 static int cifs_ci_hash(struct dentry *dentry, struct qstr *q)
 498 {
 499         struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
 500         unsigned long hash;
 501         int i;
 502
 503         hash = init_name_hash();
 504         for (i = 0; i < q->len; i++)
 505                 hash = partial_name_hash(nls_tolower(codepage, q->name[i]),
 506                                          hash);
 507         q->hash = end_name_hash(hash);
 508
 509         return 0;
 510 }
 511
 512 static int cifs_ci_compare(struct dentry *dentry, struct qstr *a,
 513                            struct qstr *b)
 514 {
 515         struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
 516
 517         if ((a->len == b->len) &&
 518             (nls_strnicmp(codepage, a->name, b->name, a->len) == 0)) {
 519                 /*
 520                  * To preserve case, don't let an existing negative dentry's
 521                  * case take precedence.  If a is not a negative dentry, this
 522                  * should have no side effects
 523                  */
 524                 memcpy((unsigned char *)a->name, b->name, a->len);
 525                 return 0;
 526         }
 527         return 1;
 528 }
 529
 530 struct dentry_operations cifs_ci_dentry_ops = {
 531         .d_revalidate = cifs_d_revalidate,
 532         .d_hash = cifs_ci_hash,
 533         .d_compare = cifs_ci_compare,
 534 };