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