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 (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->fsuid,
 204                                         (__u64)current->fsgid,
 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                                 if((oplock & CIFS_CREATE_ACTION) &&
 234                                   (cifs_sb->mnt_cifs_flags &
 235                                      CIFS_MOUNT_SET_UID)) {
 236                                         newinode->i_uid = current->fsuid;
 237                                         newinode->i_gid = current->fsgid;
 238                                 }
 239                         }
 240                 }
 241
 242                 if (rc != 0) {
 243                         cFYI(1,
 244                              ("Create worked but get_inode_info failed rc = %d",
 245                               rc));
 246                 } else {
 247                         if (pTcon->nocase)
 248                                 direntry->d_op = &cifs_ci_dentry_ops;
 249                         else
 250                                 direntry->d_op = &cifs_dentry_ops;
 251                         d_instantiate(direntry, newinode);
 252                 }
 253                 if((nd->flags & LOOKUP_OPEN) == FALSE) {
 254                         /* mknod case - do not leave file open */
 255                         CIFSSMBClose(xid, pTcon, fileHandle);
 256                 } else if(newinode) {
 257                         pCifsFile =
 258                            kmalloc(sizeof (struct cifsFileInfo), GFP_KERNEL);
 259
 260                         if(pCifsFile == NULL)
 261                                 goto cifs_create_out;
 262                         memset((char *)pCifsFile, 0,
 263                                sizeof (struct cifsFileInfo));
 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         down(&direntry->d_sb->s_vfs_rename_sem);
 321         full_path = build_path_from_dentry(direntry);
 322         up(&direntry->d_sb->s_vfs_rename_sem);
 323         if(full_path == NULL)
 324                 rc = -ENOMEM;
 325         else if (pTcon->ses->capabilities & CAP_UNIX) {
 326                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 327                         rc = CIFSSMBUnixSetPerms(xid, pTcon, full_path,
 328                                 mode,(__u64)current->fsuid,(__u64)current->fsgid,
 329                                 device_number, cifs_sb->local_nls,
 330                                 cifs_sb->mnt_cifs_flags &
 331                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 332                 } else {
 333                         rc = CIFSSMBUnixSetPerms(xid, pTcon,
 334                                 full_path, mode, (__u64)-1, (__u64)-1,
 335                                 device_number, cifs_sb->local_nls,
 336                                 cifs_sb->mnt_cifs_flags &
 337                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 338                 }
 339
 340                 if(!rc) {
 341                         rc = cifs_get_inode_info_unix(&newinode, full_path,
 342                                                 inode->i_sb,xid);
 343                         if (pTcon->nocase)
 344                                 direntry->d_op = &cifs_ci_dentry_ops;
 345                         else
 346                                 direntry->d_op = &cifs_dentry_ops;
 347                         if(rc == 0)
 348                                 d_instantiate(direntry, newinode);
 349                 }
 350         } else {
 351                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
 352                         int oplock = 0;
 353                         u16 fileHandle;
 354                         FILE_ALL_INFO * buf;
 355
 356                         cFYI(1,("sfu compat create special file"));
 357
 358                         buf = kmalloc(sizeof(FILE_ALL_INFO),GFP_KERNEL);
 359                         if(buf == NULL) {
 360                                 kfree(full_path);
 361                                 FreeXid(xid);
 362                                 return -ENOMEM;
 363                         }
 364
 365                         rc = CIFSSMBOpen(xid, pTcon, full_path,
 366                                          FILE_CREATE, /* fail if exists */
 367                                          GENERIC_WRITE /* BB would
 368                                           WRITE_OWNER | WRITE_DAC be better? */,
 369                                          /* Create a file and set the
 370                                             file attribute to SYSTEM */
 371                                          CREATE_NOT_DIR | CREATE_OPTION_SPECIAL,
 372                                          &fileHandle, &oplock, buf,
 373                                          cifs_sb->local_nls,
 374                                          cifs_sb->mnt_cifs_flags &
 375                                             CIFS_MOUNT_MAP_SPECIAL_CHR);
 376
 377                         if(!rc) {
 378                                 /* BB Do not bother to decode buf since no
 379                                    local inode yet to put timestamps in,
 380                                    but we can reuse it safely */
 381                                 int bytes_written;
 382                                 struct win_dev *pdev;
 383                                 pdev = (struct win_dev *)buf;
 384                                 if(S_ISCHR(mode)) {
 385                                         memcpy(pdev->type, "IntxCHR", 8);
 386                                         pdev->major =
 387                                               cpu_to_le64(MAJOR(device_number));
 388                                         pdev->minor =
 389                                               cpu_to_le64(MINOR(device_number));
 390                                         rc = CIFSSMBWrite(xid, pTcon,
 391                                                 fileHandle,
 392                                                 sizeof(struct win_dev),
 393                                                 0, &bytes_written, (char *)pdev,
 394                                                 NULL, 0);
 395                                 } else if(S_ISBLK(mode)) {
 396                                         memcpy(pdev->type, "IntxBLK", 8);
 397                                         pdev->major =
 398                                               cpu_to_le64(MAJOR(device_number));
 399                                         pdev->minor =
 400                                               cpu_to_le64(MINOR(device_number));
 401                                         rc = CIFSSMBWrite(xid, pTcon,
 402                                                 fileHandle,
 403                                                 sizeof(struct win_dev),
 404                                                 0, &bytes_written, (char *)pdev,
 405                                                 NULL, 0);
 406                                 } /* else if(S_ISFIFO */
 407                                 CIFSSMBClose(xid, pTcon, fileHandle);
 408                                 d_drop(direntry);
 409                         }
 410                         kfree(buf);
 411                         /* add code here to set EAs */
 412                 }
 413         }
 414
 415         kfree(full_path);
 416         FreeXid(xid);
 417         return rc;
 418 }
 419
 420
 421 struct dentry *
 422 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, struct nameidata *nd)
 423 {
 424         int xid;
 425         int rc = 0; /* to get around spurious gcc warning, set to zero here */
 426         struct cifs_sb_info *cifs_sb;
 427         struct cifsTconInfo *pTcon;
 428         struct inode *newInode = NULL;
 429         char *full_path = NULL;
 430
 431         xid = GetXid();
 432
 433         cFYI(1,
 434              (" parent inode = 0x%p name is: %s and dentry = 0x%p",
 435               parent_dir_inode, direntry->d_name.name, direntry));
 436
 437         /* BB Add check of incoming data - e.g. frame not longer than maximum SMB - let server check the namelen BB */
 438
 439         /* check whether path exists */
 440
 441         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
 442         pTcon = cifs_sb->tcon;
 443
 444         /* can not grab the rename sem here since it would
 445         deadlock in the cases (beginning of sys_rename itself)
 446         in which we already have the sb rename sem */
 447         full_path = build_path_from_dentry(direntry);
 448         if(full_path == NULL) {
 449                 FreeXid(xid);
 450                 return ERR_PTR(-ENOMEM);
 451         }
 452
 453         if (direntry->d_inode != NULL) {
 454                 cFYI(1, (" non-NULL inode in lookup"));
 455         } else {
 456                 cFYI(1, (" NULL inode in lookup"));
 457         }
 458         cFYI(1,
 459              (" Full path: %s inode = 0x%p", full_path, direntry->d_inode));
 460
 461         if (pTcon->ses->capabilities & CAP_UNIX)
 462                 rc = cifs_get_inode_info_unix(&newInode, full_path,
 463                                               parent_dir_inode->i_sb,xid);
 464         else
 465                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
 466                                          parent_dir_inode->i_sb,xid);
 467
 468         if ((rc == 0) && (newInode != NULL)) {
 469                 if (pTcon->nocase)
 470                         direntry->d_op = &cifs_ci_dentry_ops;
 471                 else
 472                         direntry->d_op = &cifs_dentry_ops;
 473                 d_add(direntry, newInode);
 474
 475                 /* since paths are not looked up by component - the parent
 476                    directories are presumed to be good here */
 477                 renew_parental_timestamps(direntry);
 478
 479         } else if (rc == -ENOENT) {
 480                 rc = 0;
 481                 direntry->d_time = jiffies;
 482                 if (pTcon->nocase)
 483                         direntry->d_op = &cifs_ci_dentry_ops;
 484                 else
 485                         direntry->d_op = &cifs_dentry_ops;
 486                 d_add(direntry, NULL);
 487         /*      if it was once a directory (but how can we tell?) we could do
 488                         shrink_dcache_parent(direntry); */
 489         } else {
 490                 cERROR(1,("Error 0x%x on cifs_get_inode_info in lookup of %s",
 491                            rc,full_path));
 492                 /* BB special case check for Access Denied - watch security
 493                 exposure of returning dir info implicitly via different rc
 494                 if file exists or not but no access BB */
 495         }
 496
 497         kfree(full_path);
 498         FreeXid(xid);
 499         return ERR_PTR(rc);
 500 }
 501
 502 static int
 503 cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
 504 {
 505         int isValid = 1;
 506
 507         if (direntry->d_inode) {
 508                 if (cifs_revalidate(direntry)) {
 509                         return 0;
 510                 }
 511         } else {
 512                 cFYI(1, ("neg dentry 0x%p name = %s",
 513                          direntry, direntry->d_name.name));
 514                 if(time_after(jiffies, direntry->d_time + HZ) ||
 515                         !lookupCacheEnabled) {
 516                         d_drop(direntry);
 517                         isValid = 0;
 518                 }
 519         }
 520
 521         return isValid;
 522 }
 523
 524 /* static int cifs_d_delete(struct dentry *direntry)
 525 {
 526         int rc = 0;
 527
 528         cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));
 529
 530         return rc;
 531 }     */
 532
 533 struct dentry_operations cifs_dentry_ops = {
 534         .d_revalidate = cifs_d_revalidate,
 535 /* d_delete:       cifs_d_delete,       *//* not needed except for debugging */
 536         /* no need for d_hash, d_compare, d_release, d_iput ... yet. BB confirm this BB */
 537 };
 538
 539 static int cifs_ci_hash(struct dentry *dentry, struct qstr *q)
 540 {
 541         struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
 542         unsigned long hash;
 543         int i;
 544
 545         hash = init_name_hash();
 546         for (i = 0; i < q->len; i++)
 547                 hash = partial_name_hash(nls_tolower(codepage, q->name[i]),
 548                                          hash);
 549         q->hash = end_name_hash(hash);
 550
 551         return 0;
 552 }
 553
 554 static int cifs_ci_compare(struct dentry *dentry, struct qstr *a,
 555                            struct qstr *b)
 556 {
 557         struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
 558
 559         if ((a->len == b->len) &&
 560             (nls_strnicmp(codepage, a->name, b->name, a->len) == 0)) {
 561                 /*
 562                  * To preserve case, don't let an existing negative dentry's
 563                  * case take precedence.  If a is not a negative dentry, this
 564                  * should have no side effects
 565                  */
 566                 memcpy((unsigned char *)a->name, b->name, a->len);
 567                 return 0;
 568         }
 569         return 1;
 570 }
 571
 572 struct dentry_operations cifs_ci_dentry_ops = {
 573         .d_revalidate = cifs_d_revalidate,
 574         .d_hash = cifs_ci_hash,
 575         .d_compare = cifs_ci_compare,
 576 };