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., 2002,2008
   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 static 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
  38            really need this */
  39         do {
  40                 direntry->d_time = jiffies;
  41                 direntry = direntry->d_parent;
  42         } while (!IS_ROOT(direntry));
  43 }
  44
  45 /* Note: caller must free return buffer */
  46 char *
  47 build_path_from_dentry(struct dentry *direntry)
  48 {
  49         struct dentry *temp;
  50         int namelen;
  51         int pplen;
  52         char *full_path;
  53         char dirsep;
  54
  55         if (direntry == NULL)
  56                 return NULL;  /* not much we can do if dentry is freed and
  57                 we need to reopen the file after it was closed implicitly
  58                 when the server crashed */
  59
  60         dirsep = CIFS_DIR_SEP(CIFS_SB(direntry->d_sb));
  61         pplen = CIFS_SB(direntry->d_sb)->prepathlen;
  62 cifs_bp_rename_retry:
  63         namelen = pplen;
  64         for (temp = direntry; !IS_ROOT(temp);) {
  65                 namelen += (1 + temp->d_name.len);
  66                 temp = temp->d_parent;
  67                 if (temp == NULL) {
  68                         cERROR(1, ("corrupt dentry"));
  69                         return NULL;
  70                 }
  71         }
  72
  73         full_path = kmalloc(namelen+1, GFP_KERNEL);
  74         if (full_path == NULL)
  75                 return full_path;
  76         full_path[namelen] = 0; /* trailing null */
  77         for (temp = direntry; !IS_ROOT(temp);) {
  78                 namelen -= 1 + temp->d_name.len;
  79                 if (namelen < 0) {
  80                         break;
  81                 } else {
  82                         full_path[namelen] = dirsep;
  83                         strncpy(full_path + namelen + 1, temp->d_name.name,
  84                                 temp->d_name.len);
  85                         cFYI(0, ("name: %s", full_path + namelen));
  86                 }
  87                 temp = temp->d_parent;
  88                 if (temp == NULL) {
  89                         cERROR(1, ("corrupt dentry"));
  90                         kfree(full_path);
  91                         return NULL;
  92                 }
  93         }
  94         if (namelen != pplen) {
  95                 cERROR(1,
  96                        ("did not end path lookup where expected namelen is %d",
  97                         namelen));
  98                 /* presumably this is only possible if racing with a rename
  99                 of one of the parent directories  (we can not lock the dentries
 100                 above us to prevent this, but retrying should be harmless) */
 101                 kfree(full_path);
 102                 goto cifs_bp_rename_retry;
 103         }
 104         /* DIR_SEP already set for byte  0 / vs \ but not for
 105            subsequent slashes in prepath which currently must
 106            be entered the right way - not sure if there is an alternative
 107            since the '\' is a valid posix character so we can not switch
 108            those safely to '/' if any are found in the middle of the prepath */
 109         /* BB test paths to Windows with '/' in the midst of prepath */
 110         strncpy(full_path, CIFS_SB(direntry->d_sb)->prepath, pplen);
 111         return full_path;
 112 }
 113
 114 /* Inode operations in similar order to how they appear in Linux file fs.h */
 115
 116 int
 117 cifs_create(struct inode *inode, struct dentry *direntry, int mode,
 118                 struct nameidata *nd)
 119 {
 120         int rc = -ENOENT;
 121         int xid;
 122         int oplock = 0;
 123         int desiredAccess = GENERIC_READ | GENERIC_WRITE;
 124         __u16 fileHandle;
 125         struct cifs_sb_info *cifs_sb;
 126         struct cifsTconInfo *pTcon;
 127         char *full_path = NULL;
 128         FILE_ALL_INFO *buf = NULL;
 129         struct inode *newinode = NULL;
 130         struct cifsFileInfo *pCifsFile = NULL;
 131         struct cifsInodeInfo *pCifsInode;
 132         int disposition = FILE_OVERWRITE_IF;
 133         int write_only = FALSE;
 134
 135         xid = GetXid();
 136
 137         cifs_sb = CIFS_SB(inode->i_sb);
 138         pTcon = cifs_sb->tcon;
 139
 140         full_path = build_path_from_dentry(direntry);
 141         if (full_path == NULL) {
 142                 FreeXid(xid);
 143                 return -ENOMEM;
 144         }
 145
 146         if (nd && (nd->flags & LOOKUP_OPEN)) {
 147                 int oflags = nd->intent.open.flags;
 148
 149                 desiredAccess = 0;
 150                 if (oflags & FMODE_READ)
 151                         desiredAccess |= GENERIC_READ;
 152                 if (oflags & FMODE_WRITE) {
 153                         desiredAccess |= GENERIC_WRITE;
 154                         if (!(oflags & FMODE_READ))
 155                                 write_only = TRUE;
 156                 }
 157
 158                 if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 159                         disposition = FILE_CREATE;
 160                 else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
 161                         disposition = FILE_OVERWRITE_IF;
 162                 else if ((oflags & O_CREAT) == O_CREAT)
 163                         disposition = FILE_OPEN_IF;
 164                 else
 165                         cFYI(1, ("Create flag not set in create function"));
 166         }
 167
 168         /* BB add processing to set equivalent of mode - e.g. via CreateX with
 169            ACLs */
 170         if (oplockEnabled)
 171                 oplock = REQ_OPLOCK;
 172
 173         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
 174         if (buf == NULL) {
 175                 kfree(full_path);
 176                 FreeXid(xid);
 177                 return -ENOMEM;
 178         }
 179         if (cifs_sb->tcon->ses->capabilities & CAP_NT_SMBS)
 180                 rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
 181                          desiredAccess, CREATE_NOT_DIR,
 182                          &fileHandle, &oplock, buf, cifs_sb->local_nls,
 183                          cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 184         else
 185                 rc = -EIO; /* no NT SMB support fall into legacy open below */
 186
 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 ((pTcon->unix_ext) && (oplock & CIFS_CREATE_ACTION)) {
 200                         mode &= ~current->fs->umask;
 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
 220                            descriptors e.g. */
 221                         /* CIFSSMBWinSetPerms(xid,pTcon,path,mode,-1,-1,nls);*/
 222
 223                         /* Could set r/o dos attribute if mode & 0222 == 0 */
 224                 }
 225
 226                 /* server might mask mode so we have to query for it */
 227                 if (pTcon->unix_ext)
 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 == NULL /* nfsd case - nfs srv does not set nd */) ||
 256                         ((nd->flags & LOOKUP_OPEN) == FALSE)) {
 257                         /* mknod case - do not leave file open */
 258                         CIFSSMBClose(xid, pTcon, fileHandle);
 259                 } else if (newinode) {
 260                         pCifsFile =
 261                            kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 262
 263                         if (pCifsFile == NULL)
 264                                 goto cifs_create_out;
 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                         mutex_init(&pCifsFile->lock_mutex);
 272                         INIT_LIST_HEAD(&pCifsFile->llist);
 273                         atomic_set(&pCifsFile->wrtPending, 0);
 274
 275                         /* set the following in open now
 276                                 pCifsFile->pfile = file; */
 277                         write_lock(&GlobalSMBSeslock);
 278                         list_add(&pCifsFile->tlist, &pTcon->openFileList);
 279                         pCifsInode = CIFS_I(newinode);
 280                         if (pCifsInode) {
 281                                 /* if readable file instance put first in list*/
 282                                 if (write_only == TRUE) {
 283                                         list_add_tail(&pCifsFile->flist,
 284                                                 &pCifsInode->openFileList);
 285                                 } else {
 286                                         list_add(&pCifsFile->flist,
 287                                                 &pCifsInode->openFileList);
 288                                 }
 289                                 if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
 290                                         pCifsInode->clientCanCacheAll = TRUE;
 291                                         pCifsInode->clientCanCacheRead = TRUE;
 292                                         cFYI(1, ("Exclusive Oplock inode %p",
 293                                                 newinode));
 294                                 } else if ((oplock & 0xF) == OPLOCK_READ)
 295                                         pCifsInode->clientCanCacheRead = TRUE;
 296                         }
 297                         write_unlock(&GlobalSMBSeslock);
 298                 }
 299         }
 300 cifs_create_out:
 301         kfree(buf);
 302         kfree(full_path);
 303         FreeXid(xid);
 304         return rc;
 305 }
 306
 307 int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
 308                 dev_t device_number)
 309 {
 310         int rc = -EPERM;
 311         int xid;
 312         struct cifs_sb_info *cifs_sb;
 313         struct cifsTconInfo *pTcon;
 314         char *full_path = NULL;
 315         struct inode *newinode = NULL;
 316
 317         if (!old_valid_dev(device_number))
 318                 return -EINVAL;
 319
 320         xid = GetXid();
 321
 322         cifs_sb = CIFS_SB(inode->i_sb);
 323         pTcon = cifs_sb->tcon;
 324
 325         full_path = build_path_from_dentry(direntry);
 326         if (full_path == NULL)
 327                 rc = -ENOMEM;
 328         else if (pTcon->unix_ext) {
 329                 mode &= ~current->fs->umask;
 330                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 331                         rc = CIFSSMBUnixSetPerms(xid, pTcon, full_path,
 332                                 mode, (__u64)current->fsuid,
 333                                 (__u64)current->fsgid,
 334                                 device_number, cifs_sb->local_nls,
 335                                 cifs_sb->mnt_cifs_flags &
 336                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 337                 } else {
 338                         rc = CIFSSMBUnixSetPerms(xid, pTcon,
 339                                 full_path, mode, (__u64)-1, (__u64)-1,
 340                                 device_number, cifs_sb->local_nls,
 341                                 cifs_sb->mnt_cifs_flags &
 342                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 343                 }
 344
 345                 if (!rc) {
 346                         rc = cifs_get_inode_info_unix(&newinode, full_path,
 347                                                 inode->i_sb, xid);
 348                         if (pTcon->nocase)
 349                                 direntry->d_op = &cifs_ci_dentry_ops;
 350                         else
 351                                 direntry->d_op = &cifs_dentry_ops;
 352                         if (rc == 0)
 353                                 d_instantiate(direntry, newinode);
 354                 }
 355         } else {
 356                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
 357                         int oplock = 0;
 358                         u16 fileHandle;
 359                         FILE_ALL_INFO *buf;
 360
 361                         cFYI(1, ("sfu compat create special file"));
 362
 363                         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
 364                         if (buf == NULL) {
 365                                 kfree(full_path);
 366                                 FreeXid(xid);
 367                                 return -ENOMEM;
 368                         }
 369
 370                         rc = CIFSSMBOpen(xid, pTcon, full_path,
 371                                          FILE_CREATE, /* fail if exists */
 372                                          GENERIC_WRITE /* BB would
 373                                           WRITE_OWNER | WRITE_DAC be better? */,
 374                                          /* Create a file and set the
 375                                             file attribute to SYSTEM */
 376                                          CREATE_NOT_DIR | CREATE_OPTION_SPECIAL,
 377                                          &fileHandle, &oplock, buf,
 378                                          cifs_sb->local_nls,
 379                                          cifs_sb->mnt_cifs_flags &
 380                                             CIFS_MOUNT_MAP_SPECIAL_CHR);
 381
 382                         /* BB FIXME - add handling for backlevel servers
 383                            which need legacy open and check for all
 384                            calls to SMBOpen for fallback to SMBLeagcyOpen */
 385                         if (!rc) {
 386                                 /* BB Do not bother to decode buf since no
 387                                    local inode yet to put timestamps in,
 388                                    but we can reuse it safely */
 389                                 unsigned int bytes_written;
 390                                 struct win_dev *pdev;
 391                                 pdev = (struct win_dev *)buf;
 392                                 if (S_ISCHR(mode)) {
 393                                         memcpy(pdev->type, "IntxCHR", 8);
 394                                         pdev->major =
 395                                               cpu_to_le64(MAJOR(device_number));
 396                                         pdev->minor =
 397                                               cpu_to_le64(MINOR(device_number));
 398                                         rc = CIFSSMBWrite(xid, pTcon,
 399                                                 fileHandle,
 400                                                 sizeof(struct win_dev),
 401                                                 0, &bytes_written, (char *)pdev,
 402                                                 NULL, 0);
 403                                 } else if (S_ISBLK(mode)) {
 404                                         memcpy(pdev->type, "IntxBLK", 8);
 405                                         pdev->major =
 406                                               cpu_to_le64(MAJOR(device_number));
 407                                         pdev->minor =
 408                                               cpu_to_le64(MINOR(device_number));
 409                                         rc = CIFSSMBWrite(xid, pTcon,
 410                                                 fileHandle,
 411                                                 sizeof(struct win_dev),
 412                                                 0, &bytes_written, (char *)pdev,
 413                                                 NULL, 0);
 414                                 } /* else if(S_ISFIFO */
 415                                 CIFSSMBClose(xid, pTcon, fileHandle);
 416                                 d_drop(direntry);
 417                         }
 418                         kfree(buf);
 419                         /* add code here to set EAs */
 420                 }
 421         }
 422
 423         kfree(full_path);
 424         FreeXid(xid);
 425         return rc;
 426 }
 427
 428
 429 struct dentry *
 430 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
 431             struct nameidata *nd)
 432 {
 433         int xid;
 434         int rc = 0; /* to get around spurious gcc warning, set to zero here */
 435         struct cifs_sb_info *cifs_sb;
 436         struct cifsTconInfo *pTcon;
 437         struct inode *newInode = NULL;
 438         char *full_path = NULL;
 439
 440         xid = GetXid();
 441
 442         cFYI(1, (" parent inode = 0x%p name is: %s and dentry = 0x%p",
 443               parent_dir_inode, direntry->d_name.name, direntry));
 444
 445         /* check whether path exists */
 446
 447         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
 448         pTcon = cifs_sb->tcon;
 449
 450         /*
 451          * Don't allow the separator character in a path component.
 452          * The VFS will not allow "/", but "\" is allowed by posix.
 453          */
 454         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
 455                 int i;
 456                 for (i = 0; i < direntry->d_name.len; i++)
 457                         if (direntry->d_name.name[i] == '\\') {
 458                                 cFYI(1, ("Invalid file name"));
 459                                 FreeXid(xid);
 460                                 return ERR_PTR(-EINVAL);
 461                         }
 462         }
 463
 464         /* can not grab the rename sem here since it would
 465         deadlock in the cases (beginning of sys_rename itself)
 466         in which we already have the sb rename sem */
 467         full_path = build_path_from_dentry(direntry);
 468         if (full_path == NULL) {
 469                 FreeXid(xid);
 470                 return ERR_PTR(-ENOMEM);
 471         }
 472
 473         if (direntry->d_inode != NULL) {
 474                 cFYI(1, (" non-NULL inode in lookup"));
 475         } else {
 476                 cFYI(1, (" NULL inode in lookup"));
 477         }
 478         cFYI(1,
 479              (" Full path: %s inode = 0x%p", full_path, direntry->d_inode));
 480
 481         if (pTcon->unix_ext)
 482                 rc = cifs_get_inode_info_unix(&newInode, full_path,
 483                                               parent_dir_inode->i_sb, xid);
 484         else
 485                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
 486                                          parent_dir_inode->i_sb, xid);
 487
 488         if ((rc == 0) && (newInode != NULL)) {
 489                 if (pTcon->nocase)
 490                         direntry->d_op = &cifs_ci_dentry_ops;
 491                 else
 492                         direntry->d_op = &cifs_dentry_ops;
 493                 d_add(direntry, newInode);
 494
 495                 /* since paths are not looked up by component - the parent
 496                    directories are presumed to be good here */
 497                 renew_parental_timestamps(direntry);
 498
 499         } else if (rc == -ENOENT) {
 500                 rc = 0;
 501                 direntry->d_time = jiffies;
 502                 if (pTcon->nocase)
 503                         direntry->d_op = &cifs_ci_dentry_ops;
 504                 else
 505                         direntry->d_op = &cifs_dentry_ops;
 506                 d_add(direntry, NULL);
 507         /*      if it was once a directory (but how can we tell?) we could do
 508                 shrink_dcache_parent(direntry); */
 509         } else if (rc != -EACCES) {
 510                 cERROR(1, ("Unexpected lookup error %d", rc));
 511                 /* We special case check for Access Denied - since that
 512                 is a common return code */
 513         }
 514
 515         kfree(full_path);
 516         FreeXid(xid);
 517         return ERR_PTR(rc);
 518 }
 519
 520 static int
 521 cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
 522 {
 523         int isValid = 1;
 524
 525         if (direntry->d_inode) {
 526                 if (cifs_revalidate(direntry))
 527                         return 0;
 528         } else {
 529                 cFYI(1, ("neg dentry 0x%p name = %s",
 530                          direntry, direntry->d_name.name));
 531                 if (time_after(jiffies, direntry->d_time + HZ) ||
 532                         !lookupCacheEnabled) {
 533                         d_drop(direntry);
 534                         isValid = 0;
 535                 }
 536         }
 537
 538         return isValid;
 539 }
 540
 541 /* static int cifs_d_delete(struct dentry *direntry)
 542 {
 543         int rc = 0;
 544
 545         cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));
 546
 547         return rc;
 548 }     */
 549
 550 struct dentry_operations cifs_dentry_ops = {
 551         .d_revalidate = cifs_d_revalidate,
 552 /* d_delete:       cifs_d_delete,      */ /* not needed except for debugging */
 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(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 };