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., 2002,2005
   7  *   Author(s): Steve French ([email protected])
   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;
  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         dirsep = CIFS_DIR_SEP(CIFS_SB(direntry->d_sb));
  59 cifs_bp_rename_retry:
  60         for (temp = direntry; !IS_ROOT(temp);) {
  61                 namelen += (1 + temp->d_name.len);
  62                 temp = temp->d_parent;
  63                 if(temp == NULL) {
  64                         cERROR(1,("corrupt dentry"));
  65                         return NULL;
  66                 }
  67         }
  68
  69         full_path = kmalloc(namelen+1, GFP_KERNEL);
  70         if(full_path == NULL)
  71                 return full_path;
  72         full_path[namelen] = 0; /* trailing null */
  73
  74         for (temp = direntry; !IS_ROOT(temp);) {
  75                 namelen -= 1 + temp->d_name.len;
  76                 if (namelen < 0) {
  77                         break;
  78                 } else {
  79                         full_path[namelen] = dirsep;
  80                         strncpy(full_path + namelen + 1, temp->d_name.name,
  81                                 temp->d_name.len);
  82                         cFYI(0, (" name: %s ", full_path + namelen));
  83                 }
  84                 temp = temp->d_parent;
  85                 if(temp == NULL) {
  86                         cERROR(1,("corrupt dentry"));
  87                         kfree(full_path);
  88                         return NULL;
  89                 }
  90         }
  91         if (namelen != 0) {
  92                 cERROR(1,
  93                        ("We did not end path lookup where we expected namelen is %d",
  94                         namelen));
  95                 /* presumably this is only possible if we were racing with a rename
  96                 of one of the parent directories  (we can not lock the dentries
  97                 above us to prevent this, but retrying should be harmless) */
  98                 kfree(full_path);
  99                 namelen = 0;
 100                 goto cifs_bp_rename_retry;
 101         }
 102
 103         return full_path;
 104 }
 105
 106 /* char * build_wildcard_path_from_dentry(struct dentry *direntry)
 107 {
 108         if(full_path == NULL)
 109                 return full_path;
 110
 111         full_path[namelen] = '\\';
 112         full_path[namelen+1] = '*';
 113         full_path[namelen+2] = 0;
 114 BB remove above eight lines BB */
 115
 116 /* Inode operations in similar order to how they appear in Linux file fs.h */
 117
 118 int
 119 cifs_create(struct inode *inode, struct dentry *direntry, int mode,
 120                 struct nameidata *nd)
 121 {
 122         int rc = -ENOENT;
 123         int xid;
 124         int oplock = 0;
 125         int desiredAccess = GENERIC_READ | GENERIC_WRITE;
 126         __u16 fileHandle;
 127         struct cifs_sb_info *cifs_sb;
 128         struct cifsTconInfo *pTcon;
 129         char *full_path = NULL;
 130         FILE_ALL_INFO * buf = NULL;
 131         struct inode *newinode = NULL;
 132         struct cifsFileInfo * pCifsFile = NULL;
 133         struct cifsInodeInfo * pCifsInode;
 134         int disposition = FILE_OVERWRITE_IF;
 135         int write_only = FALSE;
 136
 137         xid = GetXid();
 138
 139         cifs_sb = CIFS_SB(inode->i_sb);
 140         pTcon = cifs_sb->tcon;
 141
 142         full_path = build_path_from_dentry(direntry);
 143         if(full_path == NULL) {
 144                 FreeXid(xid);
 145                 return -ENOMEM;
 146         }
 147
 148         if(nd && (nd->flags & LOOKUP_OPEN)) {
 149                 int oflags = nd->intent.open.flags;
 150
 151                 desiredAccess = 0;
 152                 if (oflags & FMODE_READ)
 153                         desiredAccess |= GENERIC_READ;
 154                 if (oflags & FMODE_WRITE) {
 155                         desiredAccess |= GENERIC_WRITE;
 156                         if (!(oflags & FMODE_READ))
 157                                 write_only = TRUE;
 158                 }
 159
 160                 if((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 161                         disposition = FILE_CREATE;
 162                 else if((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
 163                         disposition = FILE_OVERWRITE_IF;
 164                 else if((oflags & O_CREAT) == O_CREAT)
 165                         disposition = FILE_OPEN_IF;
 166                 else {
 167                         cFYI(1,("Create flag not set in create function"));
 168                 }
 169         }
 170
 171         /* BB add processing to set equivalent of mode - e.g. via CreateX with ACLs */
 172         if (oplockEnabled)
 173                 oplock = REQ_OPLOCK;
 174
 175         buf = kmalloc(sizeof(FILE_ALL_INFO),GFP_KERNEL);
 176         if(buf == NULL) {
 177                 kfree(full_path);
 178                 FreeXid(xid);
 179                 return -ENOMEM;
 180         }
 181         if (cifs_sb->tcon->ses->capabilities & CAP_NT_SMBS)
 182                 rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
 183                          desiredAccess, CREATE_NOT_DIR,
 184                          &fileHandle, &oplock, buf, cifs_sb->local_nls,
 185                          cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 186         else
 187                 rc = -EIO; /* no NT SMB support fall into legacy open below */
 188
 189         if(rc == -EIO) {
 190                 /* old server, retry the open legacy style */
 191                 rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
 192                         desiredAccess, CREATE_NOT_DIR,
 193                         &fileHandle, &oplock, buf, cifs_sb->local_nls,
 194                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 195         }
 196         if (rc) {
 197                 cFYI(1, ("cifs_create returned 0x%x", rc));
 198         } else {
 199                 /* If Open reported that we actually created a file
 200                 then we now have to set the mode if possible */
 201                 if ((cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
 202                         (oplock & CIFS_CREATE_ACTION))
 203                         if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 204                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
 205                                         (__u64)current->fsuid,
 206                                         (__u64)current->fsgid,
 207                                         0 /* dev */,
 208                                         cifs_sb->local_nls,
 209                                         cifs_sb->mnt_cifs_flags &
 210                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 211                         } else {
 212                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
 213                                         (__u64)-1,
 214                                         (__u64)-1,
 215                                         0 /* dev */,
 216                                         cifs_sb->local_nls,
 217                                         cifs_sb->mnt_cifs_flags &
 218                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 219                         }
 220                 else {
 221                         /* BB implement mode setting via Windows security descriptors */
 222                         /* eg CIFSSMBWinSetPerms(xid,pTcon,full_path,mode,-1,-1,local_nls);*/
 223                         /* could set r/o dos attribute if mode & 0222 == 0 */
 224                 }
 225
 226         /* BB server might mask mode so we have to query for Unix case*/
 227                 if (pTcon->ses->capabilities & CAP_UNIX)
 228                         rc = cifs_get_inode_info_unix(&newinode, full_path,
 229                                                  inode->i_sb,xid);
 230                 else {
 231                         rc = cifs_get_inode_info(&newinode, full_path,
 232                                                  buf, inode->i_sb,xid);
 233                         if(newinode) {
 234                                 newinode->i_mode = mode;
 235                                 if((oplock & CIFS_CREATE_ACTION) &&
 236                                   (cifs_sb->mnt_cifs_flags &
 237                                      CIFS_MOUNT_SET_UID)) {
 238                                         newinode->i_uid = current->fsuid;
 239                                         newinode->i_gid = current->fsgid;
 240                                 }
 241                         }
 242                 }
 243
 244                 if (rc != 0) {
 245                         cFYI(1,
 246                              ("Create worked but get_inode_info failed rc = %d",
 247                               rc));
 248                 } else {
 249                         if (pTcon->nocase)
 250                                 direntry->d_op = &cifs_ci_dentry_ops;
 251                         else
 252                                 direntry->d_op = &cifs_dentry_ops;
 253                         d_instantiate(direntry, newinode);
 254                 }
 255                 if((nd->flags & LOOKUP_OPEN) == FALSE) {
 256                         /* mknod case - do not leave file open */
 257                         CIFSSMBClose(xid, pTcon, fileHandle);
 258                 } else if(newinode) {
 259                         pCifsFile =
 260                            kzalloc(sizeof (struct cifsFileInfo), GFP_KERNEL);
 261
 262                         if(pCifsFile == NULL)
 263                                 goto cifs_create_out;
 264                         pCifsFile->netfid = fileHandle;
 265                         pCifsFile->pid = current->tgid;
 266                         pCifsFile->pInode = newinode;
 267                         pCifsFile->invalidHandle = FALSE;
 268                         pCifsFile->closePend     = FALSE;
 269                         init_MUTEX(&pCifsFile->fh_sem);
 270                         /* set the following in open now
 271                                 pCifsFile->pfile = file; */
 272                         write_lock(&GlobalSMBSeslock);
 273                         list_add(&pCifsFile->tlist,&pTcon->openFileList);
 274                         pCifsInode = CIFS_I(newinode);
 275                         if(pCifsInode) {
 276                                 /* if readable file instance put first in list*/
 277                                 if (write_only == TRUE) {
 278                                         list_add_tail(&pCifsFile->flist,
 279                                                 &pCifsInode->openFileList);
 280                                 } else {
 281                                         list_add(&pCifsFile->flist,
 282                                                 &pCifsInode->openFileList);
 283                                 }
 284                                 if((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
 285                                         pCifsInode->clientCanCacheAll = TRUE;
 286                                         pCifsInode->clientCanCacheRead = TRUE;
 287                                         cFYI(1,("Exclusive Oplock for inode %p",
 288                                                 newinode));
 289                                 } else if((oplock & 0xF) == OPLOCK_READ)
 290                                         pCifsInode->clientCanCacheRead = TRUE;
 291                         }
 292                         write_unlock(&GlobalSMBSeslock);
 293                 }
 294         }
 295 cifs_create_out:
 296         kfree(buf);
 297         kfree(full_path);
 298         FreeXid(xid);
 299         return rc;
 300 }
 301
 302 int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
 303                 dev_t device_number)
 304 {
 305         int rc = -EPERM;
 306         int xid;
 307         struct cifs_sb_info *cifs_sb;
 308         struct cifsTconInfo *pTcon;
 309         char *full_path = NULL;
 310         struct inode * newinode = NULL;
 311
 312         if (!old_valid_dev(device_number))
 313                 return -EINVAL;
 314
 315         xid = GetXid();
 316
 317         cifs_sb = CIFS_SB(inode->i_sb);
 318         pTcon = cifs_sb->tcon;
 319
 320         full_path = build_path_from_dentry(direntry);
 321         if(full_path == NULL)
 322                 rc = -ENOMEM;
 323         else if (pTcon->ses->capabilities & CAP_UNIX) {
 324                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 325                         rc = CIFSSMBUnixSetPerms(xid, pTcon, full_path,
 326                                 mode,(__u64)current->fsuid,(__u64)current->fsgid,
 327                                 device_number, cifs_sb->local_nls,
 328                                 cifs_sb->mnt_cifs_flags &
 329                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 330                 } else {
 331                         rc = CIFSSMBUnixSetPerms(xid, pTcon,
 332                                 full_path, mode, (__u64)-1, (__u64)-1,
 333                                 device_number, cifs_sb->local_nls,
 334                                 cifs_sb->mnt_cifs_flags &
 335                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 336                 }
 337
 338                 if(!rc) {
 339                         rc = cifs_get_inode_info_unix(&newinode, full_path,
 340                                                 inode->i_sb,xid);
 341                         if (pTcon->nocase)
 342                                 direntry->d_op = &cifs_ci_dentry_ops;
 343                         else
 344                                 direntry->d_op = &cifs_dentry_ops;
 345                         if(rc == 0)
 346                                 d_instantiate(direntry, newinode);
 347                 }
 348         } else {
 349                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
 350                         int oplock = 0;
 351                         u16 fileHandle;
 352                         FILE_ALL_INFO * buf;
 353
 354                         cFYI(1,("sfu compat create special file"));
 355
 356                         buf = kmalloc(sizeof(FILE_ALL_INFO),GFP_KERNEL);
 357                         if(buf == NULL) {
 358                                 kfree(full_path);
 359                                 FreeXid(xid);
 360                                 return -ENOMEM;
 361                         }
 362
 363                         rc = CIFSSMBOpen(xid, pTcon, full_path,
 364                                          FILE_CREATE, /* fail if exists */
 365                                          GENERIC_WRITE /* BB would
 366                                           WRITE_OWNER | WRITE_DAC be better? */,
 367                                          /* Create a file and set the
 368                                             file attribute to SYSTEM */
 369                                          CREATE_NOT_DIR | CREATE_OPTION_SPECIAL,
 370                                          &fileHandle, &oplock, buf,
 371                                          cifs_sb->local_nls,
 372                                          cifs_sb->mnt_cifs_flags &
 373                                             CIFS_MOUNT_MAP_SPECIAL_CHR);
 374
 375                         /* BB FIXME - add handling for backlevel servers
 376                            which need legacy open and check for all
 377                            calls to SMBOpen for fallback to
 378                            SMBLeagcyOpen */
 379                         if(!rc) {
 380                                 /* BB Do not bother to decode buf since no
 381                                    local inode yet to put timestamps in,
 382                                    but we can reuse it safely */
 383                                 int bytes_written;
 384                                 struct win_dev *pdev;
 385                                 pdev = (struct win_dev *)buf;
 386                                 if(S_ISCHR(mode)) {
 387                                         memcpy(pdev->type, "IntxCHR", 8);
 388                                         pdev->major =
 389                                               cpu_to_le64(MAJOR(device_number));
 390                                         pdev->minor =
 391                                               cpu_to_le64(MINOR(device_number));
 392                                         rc = CIFSSMBWrite(xid, pTcon,
 393                                                 fileHandle,
 394                                                 sizeof(struct win_dev),
 395                                                 0, &bytes_written, (char *)pdev,
 396                                                 NULL, 0);
 397                                 } else if(S_ISBLK(mode)) {
 398                                         memcpy(pdev->type, "IntxBLK", 8);
 399                                         pdev->major =
 400                                               cpu_to_le64(MAJOR(device_number));
 401                                         pdev->minor =
 402                                               cpu_to_le64(MINOR(device_number));
 403                                         rc = CIFSSMBWrite(xid, pTcon,
 404                                                 fileHandle,
 405                                                 sizeof(struct win_dev),
 406                                                 0, &bytes_written, (char *)pdev,
 407                                                 NULL, 0);
 408                                 } /* else if(S_ISFIFO */
 409                                 CIFSSMBClose(xid, pTcon, fileHandle);
 410                                 d_drop(direntry);
 411                         }
 412                         kfree(buf);
 413                         /* add code here to set EAs */
 414                 }
 415         }
 416
 417         kfree(full_path);
 418         FreeXid(xid);
 419         return rc;
 420 }
 421
 422
 423 struct dentry *
 424 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, struct nameidata *nd)
 425 {
 426         int xid;
 427         int rc = 0; /* to get around spurious gcc warning, set to zero here */
 428         struct cifs_sb_info *cifs_sb;
 429         struct cifsTconInfo *pTcon;
 430         struct inode *newInode = NULL;
 431         char *full_path = NULL;
 432
 433         xid = GetXid();
 434
 435         cFYI(1,
 436              (" parent inode = 0x%p name is: %s and dentry = 0x%p",
 437               parent_dir_inode, direntry->d_name.name, direntry));
 438
 439         /* BB Add check of incoming data - e.g. frame not longer than maximum SMB - let server check the namelen BB */
 440
 441         /* check whether path exists */
 442
 443         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
 444         pTcon = cifs_sb->tcon;
 445
 446         /*
 447          * Don't allow the separator character in a path component.
 448          * The VFS will not allow "/", but "\" is allowed by posix.
 449          */
 450         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
 451                 int i;
 452                 for (i = 0; i < direntry->d_name.len; i++)
 453                         if (direntry->d_name.name[i] == '\\') {
 454                                 cFYI(1, ("Invalid file name"));
 455                                 FreeXid(xid);
 456                                 return ERR_PTR(-EINVAL);
 457                         }
 458         }
 459
 460         /* can not grab the rename sem here since it would
 461         deadlock in the cases (beginning of sys_rename itself)
 462         in which we already have the sb rename sem */
 463         full_path = build_path_from_dentry(direntry);
 464         if(full_path == NULL) {
 465                 FreeXid(xid);
 466                 return ERR_PTR(-ENOMEM);
 467         }
 468
 469         if (direntry->d_inode != NULL) {
 470                 cFYI(1, (" non-NULL inode in lookup"));
 471         } else {
 472                 cFYI(1, (" NULL inode in lookup"));
 473         }
 474         cFYI(1,
 475              (" Full path: %s inode = 0x%p", full_path, direntry->d_inode));
 476
 477         if (pTcon->ses->capabilities & CAP_UNIX)
 478                 rc = cifs_get_inode_info_unix(&newInode, full_path,
 479                                               parent_dir_inode->i_sb,xid);
 480         else
 481                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
 482                                          parent_dir_inode->i_sb,xid);
 483
 484         if ((rc == 0) && (newInode != NULL)) {
 485                 if (pTcon->nocase)
 486                         direntry->d_op = &cifs_ci_dentry_ops;
 487                 else
 488                         direntry->d_op = &cifs_dentry_ops;
 489                 d_add(direntry, newInode);
 490
 491                 /* since paths are not looked up by component - the parent
 492                    directories are presumed to be good here */
 493                 renew_parental_timestamps(direntry);
 494
 495         } else if (rc == -ENOENT) {
 496                 rc = 0;
 497                 direntry->d_time = jiffies;
 498                 if (pTcon->nocase)
 499                         direntry->d_op = &cifs_ci_dentry_ops;
 500                 else
 501                         direntry->d_op = &cifs_dentry_ops;
 502                 d_add(direntry, NULL);
 503         /*      if it was once a directory (but how can we tell?) we could do
 504                         shrink_dcache_parent(direntry); */
 505         } else {
 506                 cERROR(1,("Error 0x%x on cifs_get_inode_info in lookup of %s",
 507                            rc,full_path));
 508                 /* BB special case check for Access Denied - watch security
 509                 exposure of returning dir info implicitly via different rc
 510                 if file exists or not but no access BB */
 511         }
 512
 513         kfree(full_path);
 514         FreeXid(xid);
 515         return ERR_PTR(rc);
 516 }
 517
 518 static int
 519 cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
 520 {
 521         int isValid = 1;
 522
 523         if (direntry->d_inode) {
 524                 if (cifs_revalidate(direntry)) {
 525                         return 0;
 526                 }
 527         } else {
 528                 cFYI(1, ("neg dentry 0x%p name = %s",
 529                          direntry, direntry->d_name.name));
 530                 if(time_after(jiffies, direntry->d_time + HZ) ||
 531                         !lookupCacheEnabled) {
 532                         d_drop(direntry);
 533                         isValid = 0;
 534                 }
 535         }
 536
 537         return isValid;
 538 }
 539
 540 /* static int cifs_d_delete(struct dentry *direntry)
 541 {
 542         int rc = 0;
 543
 544         cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));
 545
 546         return rc;
 547 }     */
 548
 549 struct dentry_operations cifs_dentry_ops = {
 550         .d_revalidate = cifs_d_revalidate,
 551 /* d_delete:       cifs_d_delete,       *//* not needed except for debugging */
 552         /* no need for d_hash, d_compare, d_release, d_iput ... yet. BB confirm this BB */
 553 };
 554
 555 static int cifs_ci_hash(struct dentry *dentry, struct qstr *q)
 556 {
 557         struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
 558         unsigned long hash;
 559         int i;
 560
 561         hash = init_name_hash();
 562         for (i = 0; i < q->len; i++)
 563                 hash = partial_name_hash(nls_tolower(codepage, q->name[i]),
 564                                          hash);
 565         q->hash = end_name_hash(hash);
 566
 567         return 0;
 568 }
 569
 570 static int cifs_ci_compare(struct dentry *dentry, struct qstr *a,
 571                            struct qstr *b)
 572 {
 573         struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
 574
 575         if ((a->len == b->len) &&
 576             (nls_strnicmp(codepage, a->name, b->name, a->len) == 0)) {
 577                 /*
 578                  * To preserve case, don't let an existing negative dentry's
 579                  * case take precedence.  If a is not a negative dentry, this
 580                  * should have no side effects
 581                  */
 582                 memcpy((unsigned char *)a->name, b->name, a->len);
 583                 return 0;
 584         }
 585         return 1;
 586 }
 587
 588 struct dentry_operations cifs_ci_dentry_ops = {
 589         .d_revalidate = cifs_d_revalidate,
 590         .d_hash = cifs_ci_hash,
 591         .d_compare = cifs_ci_compare,
 592 };