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
 163         xid = GetXid();
 164
 165         cifs_sb = CIFS_SB(inode->i_sb);
 166         pTcon = cifs_sb->tcon;
 167
 168         down(&direntry->d_sb->s_vfs_rename_sem);
 169         full_path = build_path_from_dentry(direntry);
 170         up(&direntry->d_sb->s_vfs_rename_sem);
 171         if(full_path == NULL) {
 172                 FreeXid(xid);
 173                 return -ENOMEM;
 174         }
 175
 176         if(nd) {
 177                 if ((nd->intent.open.flags & O_ACCMODE) == O_RDONLY)
 178                         desiredAccess = GENERIC_READ;
 179                 else if ((nd->intent.open.flags & O_ACCMODE) == O_WRONLY)
 180                         desiredAccess = GENERIC_WRITE;
 181                 else if ((nd->intent.open.flags & O_ACCMODE) == O_RDWR) {
 182                         /* GENERIC_ALL is too much permission to request */
 183                         /* can cause unnecessary access denied on create */
 184                         /* desiredAccess = GENERIC_ALL; */
 185                         desiredAccess = GENERIC_READ | GENERIC_WRITE;
 186                 }
 187
 188                 if((nd->intent.open.flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 189                         disposition = FILE_CREATE;
 190                 else if((nd->intent.open.flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
 191                         disposition = FILE_OVERWRITE_IF;
 192                 else if((nd->intent.open.flags & O_CREAT) == O_CREAT)
 193                         disposition = FILE_OPEN_IF;
 194                 else {
 195                         cFYI(1,("Create flag not set in create function"));
 196                 }
 197         }
 198
 199         /* BB add processing to set equivalent of mode - e.g. via CreateX with ACLs */
 200         if (oplockEnabled)
 201                 oplock = REQ_OPLOCK;
 202
 203         buf = kmalloc(sizeof(FILE_ALL_INFO),GFP_KERNEL);
 204         if(buf == NULL) {
 205                 kfree(full_path);
 206                 FreeXid(xid);
 207                 return -ENOMEM;
 208         }
 209
 210         rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
 211                          desiredAccess, CREATE_NOT_DIR,
 212                          &fileHandle, &oplock, buf, cifs_sb->local_nls);
 213         if (rc) {
 214                 cFYI(1, ("cifs_create returned 0x%x ", rc));
 215         } else {
 216                 /* If Open reported that we actually created a file
 217                 then we now have to set the mode if possible */
 218                 if ((cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
 219                         (oplock & CIFS_CREATE_ACTION))
 220                         CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
 221                                         (__u64)-1,
 222                                         (__u64)-1,
 223                                         0 /* dev */,
 224                                         cifs_sb->local_nls);
 225                 else {
 226                         /* BB implement via Windows security descriptors */
 227                         /* eg CIFSSMBWinSetPerms(xid,pTcon,full_path,mode,-1,-1,local_nls);*/
 228                         /* could set r/o dos attribute if mode & 0222 == 0 */
 229                 }
 230
 231         /* BB server might mask mode so we have to query for Unix case*/
 232                 if (pTcon->ses->capabilities & CAP_UNIX)
 233                         rc = cifs_get_inode_info_unix(&newinode, full_path,
 234                                                  inode->i_sb);
 235                 else {
 236                         rc = cifs_get_inode_info(&newinode, full_path,
 237                                                  buf, inode->i_sb);
 238                         if(newinode)
 239                                 newinode->i_mode = mode;
 240                 }
 241
 242                 if (rc != 0) {
 243                         cFYI(1,("Create worked but get_inode_info failed with rc = %d",
 244                               rc));
 245                 } else {
 246                         direntry->d_op = &cifs_dentry_ops;
 247                         d_instantiate(direntry, newinode);
 248                 }
 249                 if((nd->flags & LOOKUP_OPEN) == FALSE) {
 250                         /* mknod case - do not leave file open */
 251                         CIFSSMBClose(xid, pTcon, fileHandle);
 252                 } else if(newinode) {
 253                         pCifsFile = (struct cifsFileInfo *)
 254                            kmalloc(sizeof (struct cifsFileInfo), GFP_KERNEL);
 255
 256                         if (pCifsFile) {
 257                                 memset((char *)pCifsFile, 0,
 258                                        sizeof (struct cifsFileInfo));
 259                                 pCifsFile->netfid = fileHandle;
 260                                 pCifsFile->pid = current->tgid;
 261                                 pCifsFile->pInode = newinode;
 262                                 pCifsFile->invalidHandle = FALSE;
 263                                 pCifsFile->closePend     = FALSE;
 264                                 init_MUTEX(&pCifsFile->fh_sem);
 265                                 /* pCifsFile->pfile = file; */ /* put in at open time */
 266                                 write_lock(&GlobalSMBSeslock);
 267                                 list_add(&pCifsFile->tlist,&pTcon->openFileList);
 268                                 pCifsInode = CIFS_I(newinode);
 269                                 if(pCifsInode) {
 270                                         list_add(&pCifsFile->flist,&pCifsInode->openFileList);
 271                                         if((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
 272                                                 pCifsInode->clientCanCacheAll = TRUE;
 273                                                 pCifsInode->clientCanCacheRead = TRUE;
 274                                                 cFYI(1,("Exclusive Oplock granted on inode %p",newinode));
 275                                         } else if((oplock & 0xF) == OPLOCK_READ)
 276                                                 pCifsInode->clientCanCacheRead = TRUE;
 277                                 }
 278                                 write_unlock(&GlobalSMBSeslock);
 279                         }
 280                 }
 281         }
 282
 283         if (buf)
 284             kfree(buf);
 285         if (full_path)
 286             kfree(full_path);
 287         FreeXid(xid);
 288
 289         return rc;
 290 }
 291
 292 int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode, dev_t device_number)
 293 {
 294         int rc = -EPERM;
 295         int xid;
 296         struct cifs_sb_info *cifs_sb;
 297         struct cifsTconInfo *pTcon;
 298         char *full_path = NULL;
 299         struct inode * newinode = NULL;
 300
 301         if (!old_valid_dev(device_number))
 302                 return -EINVAL;
 303
 304         xid = GetXid();
 305
 306         cifs_sb = CIFS_SB(inode->i_sb);
 307         pTcon = cifs_sb->tcon;
 308
 309         down(&direntry->d_sb->s_vfs_rename_sem);
 310         full_path = build_path_from_dentry(direntry);
 311         up(&direntry->d_sb->s_vfs_rename_sem);
 312         if(full_path == NULL)
 313                 rc = -ENOMEM;
 314
 315         if (full_path && (pTcon->ses->capabilities & CAP_UNIX)) {
 316                 rc = CIFSSMBUnixSetPerms(xid, pTcon,
 317                         full_path, mode, current->euid, current->egid,
 318                         device_number, cifs_sb->local_nls);
 319                 if(!rc) {
 320                         rc = cifs_get_inode_info_unix(&newinode, full_path,
 321                                                 inode->i_sb);
 322                         direntry->d_op = &cifs_dentry_ops;
 323                         if(rc == 0)
 324                                 d_instantiate(direntry, newinode);
 325                 }
 326         }
 327
 328         if (full_path)
 329                 kfree(full_path);
 330         FreeXid(xid);
 331
 332         return rc;
 333 }
 334
 335
 336 struct dentry *
 337 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, struct nameidata *nd)
 338 {
 339         int xid;
 340         int rc = 0; /* to get around spurious gcc warning, set to zero here */
 341         struct cifs_sb_info *cifs_sb;
 342         struct cifsTconInfo *pTcon;
 343         struct inode *newInode = NULL;
 344         char *full_path = NULL;
 345
 346         xid = GetXid();
 347
 348         cFYI(1,
 349              (" parent inode = 0x%p name is: %s and dentry = 0x%p",
 350               parent_dir_inode, direntry->d_name.name, direntry));
 351
 352         if(nd) {  /* BB removeme */
 353                 cFYI(1,("In lookup nd flags 0x%x open intent flags 0x%x",nd->flags,nd->intent.open.flags));
 354         } /* BB removeme BB */
 355         /* BB Add check of incoming data - e.g. frame not longer than maximum SMB - let server check the namelen BB */
 356
 357         /* check whether path exists */
 358
 359         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
 360         pTcon = cifs_sb->tcon;
 361
 362         /* can not grab the rename sem here since it would
 363         deadlock in the cases (beginning of sys_rename itself)
 364         in which we already have the sb rename sem */
 365         full_path = build_path_from_dentry(direntry);
 366         if(full_path == NULL) {
 367                 FreeXid(xid);
 368                 return ERR_PTR(-ENOMEM);
 369         }
 370
 371         if (direntry->d_inode != NULL) {
 372                 cFYI(1, (" non-NULL inode in lookup"));
 373         } else {
 374                 cFYI(1, (" NULL inode in lookup"));
 375         }
 376         cFYI(1,
 377              (" Full path: %s inode = 0x%p", full_path, direntry->d_inode));
 378
 379         if (pTcon->ses->capabilities & CAP_UNIX)
 380                 rc = cifs_get_inode_info_unix(&newInode, full_path,
 381                                               parent_dir_inode->i_sb);
 382         else
 383                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
 384                                          parent_dir_inode->i_sb);
 385
 386         if ((rc == 0) && (newInode != NULL)) {
 387                 direntry->d_op = &cifs_dentry_ops;
 388                 d_add(direntry, newInode);
 389
 390                 /* since paths are not looked up by component - the parent directories are presumed to be good here */
 391                 renew_parental_timestamps(direntry);
 392
 393         } else if (rc == -ENOENT) {
 394                 rc = 0;
 395                 d_add(direntry, NULL);
 396         } else {
 397                 cERROR(1,("Error 0x%x or on cifs_get_inode_info in lookup",rc));
 398                 /* BB special case check for Access Denied - watch security
 399                 exposure of returning dir info implicitly via different rc
 400                 if file exists or not but no access BB */
 401         }
 402
 403         if (full_path)
 404                 kfree(full_path);
 405         FreeXid(xid);
 406         return ERR_PTR(rc);
 407 }
 408
 409 int
 410 cifs_dir_open(struct inode *inode, struct file *file)
 411 {                               /* NB: currently unused since searches are opened in readdir */
 412         int rc = 0;
 413         int xid;
 414         struct cifs_sb_info *cifs_sb;
 415         struct cifsTconInfo *pTcon;
 416         char *full_path = NULL;
 417
 418         xid = GetXid();
 419
 420         cifs_sb = CIFS_SB(inode->i_sb);
 421         pTcon = cifs_sb->tcon;
 422
 423         full_path = build_wildcard_path_from_dentry(file->f_dentry);
 424
 425         cFYI(1, (" inode = 0x%p and full path is %s", inode, full_path));
 426
 427         if (full_path)
 428                 kfree(full_path);
 429         FreeXid(xid);
 430         return rc;
 431 }
 432
 433 static int
 434 cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
 435 {
 436         int isValid = 1;
 437
 438 /*      lock_kernel(); *//* surely we do not want to lock the kernel for a whole network round trip which could take seconds */
 439
 440         if (direntry->d_inode) {
 441                 if (cifs_revalidate(direntry)) {
 442                         /* unlock_kernel(); */
 443                         return 0;
 444                 }
 445         } else {
 446                 cFYI(1,
 447                      ("In cifs_d_revalidate with no inode but name = %s and dentry 0x%p",
 448                       direntry->d_name.name, direntry));
 449         }
 450
 451 /*    unlock_kernel(); */
 452
 453         return isValid;
 454 }
 455
 456 /* static int cifs_d_delete(struct dentry *direntry)
 457 {
 458         int rc = 0;
 459
 460         cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));
 461
 462         return rc;
 463 }     */
 464
 465 struct dentry_operations cifs_dentry_ops = {
 466         .d_revalidate = cifs_d_revalidate,
 467 /* d_delete:       cifs_d_delete,       *//* not needed except for debugging */
 468         /* no need for d_hash, d_compare, d_release, d_iput ... yet. BB confirm this BB */
 469 };