fs/cifs/dir.c

   1 /*
   2  *   fs/cifs/dir.c
   3  *
   4  *   vfs operations that deal with dentries
   5  *
   6  *   Copyright (C) International Business Machines  Corp., 2002,2003
   7  *   Author(s): Steve French (sfrench@us.ibm.com)
   8  *
   9  *   This library is free software; you can redistribute it and/or modify
  10  *   it under the terms of the GNU Lesser General Public License as published
  11  *   by the Free Software Foundation; either version 2.1 of the License, or
  12  *   (at your option) any later version.
  13  *
  14  *   This library is distributed in the hope that it will be useful,
  15  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  17  *   the GNU Lesser General Public License for more details.
  18  *
  19  *   You should have received a copy of the GNU Lesser General Public License
  20  *   along with this library; if not, write to the Free Software
  21  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  */
  23 #include <linux/fs.h>
  24 #include <linux/stat.h>
  25 #include <linux/slab.h>
  26 #include <linux/namei.h>
  27 #include "cifsfs.h"
  28 #include "cifspdu.h"
  29 #include "cifsglob.h"
  30 #include "cifsproto.h"
  31 #include "cifs_debug.h"
  32 #include "cifs_fs_sb.h"
  33
  34 void
  35 renew_parental_timestamps(struct dentry *direntry)
  36 {
  37         /* BB check if there is a way to get the kernel to do this or if we really need this */
  38         do {
  39                 direntry->d_time = jiffies;
  40                 direntry = direntry->d_parent;
  41         } while (!IS_ROOT(direntry));
  42 }
  43
  44 /* Note: caller must free return buffer */
  45 char *
  46 build_path_from_dentry(struct dentry *direntry)
  47 {
  48         struct dentry *temp;
  49         int namelen = 0;
  50         char *full_path;
  51
  52         if(direntry == NULL)
  53                 return NULL;  /* not much we can do if dentry is freed and
  54                 we need to reopen the file after it was closed implicitly
  55                 when the server crashed */
  56
  57 cifs_bp_rename_retry:
  58         for (temp = direntry; !IS_ROOT(temp);) {
  59                 namelen += (1 + temp->d_name.len);
  60                 temp = temp->d_parent;
  61                 if(temp == NULL) {
  62                         cERROR(1,("corrupt dentry"));
  63                         return NULL;
  64                 }
  65         }
  66
  67         full_path = kmalloc(namelen+1, GFP_KERNEL);
  68         if(full_path == NULL)
  69                 return full_path;
  70         full_path[namelen] = 0; /* trailing null */
  71
  72         for (temp = direntry; !IS_ROOT(temp);) {
  73                 namelen -= 1 + temp->d_name.len;
  74                 if (namelen < 0) {
  75                         break;
  76                 } else {
  77                         full_path[namelen] = '\\';
  78                         strncpy(full_path + namelen + 1, temp->d_name.name,
  79                                 temp->d_name.len);
  80                         cFYI(0, (" name: %s ", full_path + namelen));
  81                 }
  82                 temp = temp->d_parent;
  83                 if(temp == NULL) {
  84                         cERROR(1,("corrupt dentry"));
  85                         kfree(full_path);
  86                         return NULL;
  87                 }
  88         }
  89         if (namelen != 0) {
  90                 cERROR(1,
  91                        ("We did not end path lookup where we expected namelen is %d",
  92                         namelen));
  93                 /* presumably this is only possible if we were racing with a rename
  94                 of one of the parent directories  (we can not lock the dentries
  95                 above us to prevent this, but retrying should be harmless) */
  96                 kfree(full_path);
  97                 namelen = 0;
  98                 goto cifs_bp_rename_retry;
  99         }
 100
 101         return full_path;
 102 }
 103
 104 char *
 105 build_wildcard_path_from_dentry(struct dentry *direntry)
 106 {
 107         struct dentry *temp;
 108         int namelen = 0;
 109         char *full_path;
 110
 111         for (temp = direntry; !IS_ROOT(temp);) {
 112                 namelen += (1 + temp->d_name.len);
 113                 temp = temp->d_parent;
 114         }
 115         namelen += 3;           /* allow for trailing null and wildcard (slash and *) */
 116         full_path = kmalloc(namelen, GFP_KERNEL);
 117         namelen--;
 118         full_path[namelen] = 0; /* trailing null */
 119         namelen--;
 120         full_path[namelen] = '*';
 121         namelen--;
 122         full_path[namelen] = '\\';
 123
 124         for (temp = direntry; !IS_ROOT(temp);) {
 125                 namelen -= 1 + temp->d_name.len;
 126                 if (namelen < 0) {
 127                         break;
 128                 } else {
 129                         full_path[namelen] = '\\';
 130                         strncpy(full_path + namelen + 1, temp->d_name.name,
 131                                 temp->d_name.len);
 132                 }
 133                 temp = temp->d_parent;
 134         }
 135         if (namelen != 0)
 136                 cERROR(1,
 137                        ("We did not end path lookup where we expected namelen is %d",
 138                         namelen));
 139
 140         return full_path;
 141 }
 142
 143 /* Inode operations in similar order to how they appear in the Linux file fs.h */
 144
 145 int
 146 cifs_create(struct inode *inode, struct dentry *direntry, int mode,
 147                 struct nameidata *nd)
 148 {
 149         int rc = -ENOENT;
 150         int xid;
 151         int oplock = 0;
 152         int desiredAccess = GENERIC_READ | GENERIC_WRITE;
 153         __u16 fileHandle;
 154         struct cifs_sb_info *cifs_sb;
 155         struct cifsTconInfo *pTcon;
 156         char *full_path = NULL;
 157         FILE_ALL_INFO * buf = NULL;
 158         struct inode *newinode = NULL;
 159         struct cifsFileInfo * pCifsFile = NULL;
 160         struct cifsInodeInfo * pCifsInode;
 161         int disposition = FILE_OVERWRITE_IF;
 162         int write_only = FALSE;
 163
 164         xid = GetXid();
 165
 166         cifs_sb = CIFS_SB(inode->i_sb);
 167         pTcon = cifs_sb->tcon;
 168
 169         down(&direntry->d_sb->s_vfs_rename_sem);
 170         full_path = build_path_from_dentry(direntry);
 171         up(&direntry->d_sb->s_vfs_rename_sem);
 172         if(full_path == NULL) {
 173                 FreeXid(xid);
 174                 return -ENOMEM;
 175         }
 176
 177         if(nd) {
 178                 if ((nd->intent.open.flags & O_ACCMODE) == O_RDONLY)
 179                         desiredAccess = GENERIC_READ;
 180                 else if ((nd->intent.open.flags & O_ACCMODE) == O_WRONLY) {
 181                         desiredAccess = GENERIC_WRITE;
 182                         write_only = TRUE;
 183                 } else if ((nd->intent.open.flags & O_ACCMODE) == O_RDWR) {
 184                         /* GENERIC_ALL is too much permission to request */
 185                         /* can cause unnecessary access denied on create */
 186                         /* desiredAccess = GENERIC_ALL; */
 187                         desiredAccess = GENERIC_READ | GENERIC_WRITE;
 188                 }
 189
 190                 if((nd->intent.open.flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 191                         disposition = FILE_CREATE;
 192                 else if((nd->intent.open.flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
 193                         disposition = FILE_OVERWRITE_IF;
 194                 else if((nd->intent.open.flags & O_CREAT) == O_CREAT)
 195                         disposition = FILE_OPEN_IF;
 196                 else {
 197                         cFYI(1,("Create flag not set in create function"));
 198                 }
 199         }
 200
 201         /* BB add processing to set equivalent of mode - e.g. via CreateX with ACLs */
 202         if (oplockEnabled)
 203                 oplock = REQ_OPLOCK;
 204
 205         buf = kmalloc(sizeof(FILE_ALL_INFO),GFP_KERNEL);
 206         if(buf == NULL) {
 207                 kfree(full_path);
 208                 FreeXid(xid);
 209                 return -ENOMEM;
 210         }
 211
 212         rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
 213                          desiredAccess, CREATE_NOT_DIR,
 214                          &fileHandle, &oplock, buf, cifs_sb->local_nls);
 215         if (rc) {
 216                 cFYI(1, ("cifs_create returned 0x%x ", rc));
 217         } else {
 218                 /* If Open reported that we actually created a file
 219                 then we now have to set the mode if possible */
 220                 if ((cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
 221                         (oplock & CIFS_CREATE_ACTION))
 222                         CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
 223                                         (__u64)-1,
 224                                         (__u64)-1,
 225                                         0 /* dev */,
 226                                         cifs_sb->local_nls);
 227                 else {
 228                         /* BB implement via Windows security descriptors */
 229                         /* eg CIFSSMBWinSetPerms(xid,pTcon,full_path,mode,-1,-1,local_nls);*/
 230                         /* could set r/o dos attribute if mode & 0222 == 0 */
 231                 }
 232
 233         /* BB server might mask mode so we have to query for Unix case*/
 234                 if (pTcon->ses->capabilities & CAP_UNIX)
 235                         rc = cifs_get_inode_info_unix(&newinode, full_path,
 236                                                  inode->i_sb);
 237                 else {
 238                         rc = cifs_get_inode_info(&newinode, full_path,
 239                                                  buf, inode->i_sb);
 240                         if(newinode)
 241                                 newinode->i_mode = mode;
 242                 }
 243
 244                 if (rc != 0) {
 245                         cFYI(1,("Create worked but get_inode_info failed with rc = %d",
 246                               rc));
 247                 } else {
 248                         direntry->d_op = &cifs_dentry_ops;
 249                         d_instantiate(direntry, newinode);
 250                 }
 251                 if((nd->flags & LOOKUP_OPEN) == FALSE) {
 252                         /* mknod case - do not leave file open */
 253                         CIFSSMBClose(xid, pTcon, fileHandle);
 254                 } else if(newinode) {
 255                         pCifsFile = (struct cifsFileInfo *)
 256                            kmalloc(sizeof (struct cifsFileInfo), GFP_KERNEL);
 257
 258                         if (pCifsFile) {
 259                                 memset((char *)pCifsFile, 0,
 260                                        sizeof (struct cifsFileInfo));
 261                                 pCifsFile->netfid = fileHandle;
 262                                 pCifsFile->pid = current->tgid;
 263                                 pCifsFile->pInode = newinode;
 264                                 pCifsFile->invalidHandle = FALSE;
 265                                 pCifsFile->closePend     = FALSE;
 266                                 init_MUTEX(&pCifsFile->fh_sem);
 267                                 /* put the following in at open now */
 268                                 /* pCifsFile->pfile = file; */
 269                                 write_lock(&GlobalSMBSeslock);
 270                                 list_add(&pCifsFile->tlist,&pTcon->openFileList);
 271                                 pCifsInode = CIFS_I(newinode);
 272                                 if(pCifsInode) {
 273                                 /* if readable file instance put first in list*/
 274                                         if (write_only == TRUE) {
 275                                                 list_add_tail(&pCifsFile->flist,
 276                                                         &pCifsInode->openFileList);
 277                                         } else {
 278                                                 list_add(&pCifsFile->flist,
 279                                                         &pCifsInode->openFileList);
 280                                         }
 281                                         if((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
 282                                                 pCifsInode->clientCanCacheAll = TRUE;
 283                                                 pCifsInode->clientCanCacheRead = TRUE;
 284                                                 cFYI(1,("Exclusive Oplock granted on inode %p",
 285                                                         newinode));
 286                                         } else if((oplock & 0xF) == OPLOCK_READ)
 287                                                 pCifsInode->clientCanCacheRead = TRUE;
 288                                 }
 289                                 write_unlock(&GlobalSMBSeslock);
 290                         }
 291                 }
 292         }
 293
 294         if (buf)
 295             kfree(buf);
 296         if (full_path)
 297             kfree(full_path);
 298         FreeXid(xid);
 299
 300         return rc;
 301 }
 302
 303 int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode, 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
 326         if (full_path && (pTcon->ses->capabilities & CAP_UNIX)) {
 327                 rc = CIFSSMBUnixSetPerms(xid, pTcon,
 328                         full_path, mode, current->euid, current->egid,
 329                         device_number, cifs_sb->local_nls);
 330                 if(!rc) {
 331                         rc = cifs_get_inode_info_unix(&newinode, full_path,
 332                                                 inode->i_sb);
 333                         direntry->d_op = &cifs_dentry_ops;
 334                         if(rc == 0)
 335                                 d_instantiate(direntry, newinode);
 336                 }
 337         }
 338
 339         if (full_path)
 340                 kfree(full_path);
 341         FreeXid(xid);
 342
 343         return rc;
 344 }
 345
 346
 347 struct dentry *
 348 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, struct nameidata *nd)
 349 {
 350         int xid;
 351         int rc = 0; /* to get around spurious gcc warning, set to zero here */
 352         struct cifs_sb_info *cifs_sb;
 353         struct cifsTconInfo *pTcon;
 354         struct inode *newInode = NULL;
 355         char *full_path = NULL;
 356
 357         xid = GetXid();
 358
 359         cFYI(1,
 360              (" parent inode = 0x%p name is: %s and dentry = 0x%p",
 361               parent_dir_inode, direntry->d_name.name, direntry));
 362
 363         if(nd) {  /* BB removeme */
 364                 cFYI(1,("In lookup nd flags 0x%x open intent flags 0x%x",nd->flags,nd->intent.open.flags));
 365         } /* BB removeme BB */
 366         /* BB Add check of incoming data - e.g. frame not longer than maximum SMB - let server check the namelen BB */
 367
 368         /* check whether path exists */
 369
 370         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
 371         pTcon = cifs_sb->tcon;
 372
 373         /* can not grab the rename sem here since it would
 374         deadlock in the cases (beginning of sys_rename itself)
 375         in which we already have the sb rename sem */
 376         full_path = build_path_from_dentry(direntry);
 377         if(full_path == NULL) {
 378                 FreeXid(xid);
 379                 return ERR_PTR(-ENOMEM);
 380         }
 381
 382         if (direntry->d_inode != NULL) {
 383                 cFYI(1, (" non-NULL inode in lookup"));
 384         } else {
 385                 cFYI(1, (" NULL inode in lookup"));
 386         }
 387         cFYI(1,
 388              (" Full path: %s inode = 0x%p", full_path, direntry->d_inode));
 389
 390         if (pTcon->ses->capabilities & CAP_UNIX)
 391                 rc = cifs_get_inode_info_unix(&newInode, full_path,
 392                                               parent_dir_inode->i_sb);
 393         else
 394                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
 395                                          parent_dir_inode->i_sb);
 396
 397         if ((rc == 0) && (newInode != NULL)) {
 398                 direntry->d_op = &cifs_dentry_ops;
 399                 d_add(direntry, newInode);
 400
 401                 /* since paths are not looked up by component - the parent directories are presumed to be good here */
 402                 renew_parental_timestamps(direntry);
 403
 404         } else if (rc == -ENOENT) {
 405                 rc = 0;
 406                 d_add(direntry, NULL);
 407         } else {
 408                 cERROR(1,("Error 0x%x or on cifs_get_inode_info in lookup",rc));
 409                 /* BB special case check for Access Denied - watch security
 410                 exposure of returning dir info implicitly via different rc
 411                 if file exists or not but no access BB */
 412         }
 413
 414         if (full_path)
 415                 kfree(full_path);
 416         FreeXid(xid);
 417         return ERR_PTR(rc);
 418 }
 419
 420 int
 421 cifs_dir_open(struct inode *inode, struct file *file)
 422 {                               /* NB: currently unused since searches are opened in readdir */
 423         int rc = 0;
 424         int xid;
 425         struct cifs_sb_info *cifs_sb;
 426         struct cifsTconInfo *pTcon;
 427         char *full_path = NULL;
 428
 429         xid = GetXid();
 430
 431         cifs_sb = CIFS_SB(inode->i_sb);
 432         pTcon = cifs_sb->tcon;
 433
 434         full_path = build_wildcard_path_from_dentry(file->f_dentry);
 435
 436         cFYI(1, (" inode = 0x%p and full path is %s", inode, full_path));
 437
 438         if (full_path)
 439                 kfree(full_path);
 440         FreeXid(xid);
 441         return rc;
 442 }
 443
 444 static int
 445 cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
 446 {
 447         int isValid = 1;
 448
 449 /*      lock_kernel(); *//* surely we do not want to lock the kernel for a whole network round trip which could take seconds */
 450
 451         if (direntry->d_inode) {
 452                 if (cifs_revalidate(direntry)) {
 453                         /* unlock_kernel(); */
 454                         return 0;
 455                 }
 456         } else {
 457                 cFYI(1,
 458                      ("In cifs_d_revalidate with no inode but name = %s and dentry 0x%p",
 459                       direntry->d_name.name, direntry));
 460         }
 461
 462 /*    unlock_kernel(); */
 463
 464         return isValid;
 465 }
 466
 467 /* static int cifs_d_delete(struct dentry *direntry)
 468 {
 469         int rc = 0;
 470
 471         cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));
 472
 473         return rc;
 474 }     */
 475
 476 struct dentry_operations cifs_dentry_ops = {
 477         .d_revalidate = cifs_d_revalidate,
 478 /* d_delete:       cifs_d_delete,       *//* not needed except for debugging */
 479         /* no need for d_hash, d_compare, d_release, d_iput ... yet. BB confirm this BB */
 480 };