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 * build_wildcard_path_from_dentry(struct dentry *direntry)
 105 {
 106         if(full_path == NULL)
 107                 return full_path;
 108
 109         full_path[namelen] = '\\';
 110         full_path[namelen+1] = '*';
 111         full_path[namelen+2] = 0;
 112 BB remove above eight lines BB */
 113
 114 /* Inode operations in similar order to how they appear in the 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         down(&direntry->d_sb->s_vfs_rename_sem);
 141         full_path = build_path_from_dentry(direntry);
 142         up(&direntry->d_sb->s_vfs_rename_sem);
 143         if(full_path == NULL) {
 144                 FreeXid(xid);
 145                 return -ENOMEM;
 146         }
 147
 148         if(nd && (nd->flags & LOOKUP_OPEN)) {
 149                 int oflags = nd->intent.open.flags;
 150
 151                 desiredAccess = 0;
 152                 if (oflags & FMODE_READ)
 153                         desiredAccess |= GENERIC_READ;
 154                 if (oflags & FMODE_WRITE) {
 155                         desiredAccess |= GENERIC_WRITE;
 156                         if (!(oflags & FMODE_READ))
 157                                 write_only = TRUE;
 158                 }
 159
 160                 if((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 161                         disposition = FILE_CREATE;
 162                 else if((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
 163                         disposition = FILE_OVERWRITE_IF;
 164                 else if((oflags & O_CREAT) == O_CREAT)
 165                         disposition = FILE_OPEN_IF;
 166                 else {
 167                         cFYI(1,("Create flag not set in create function"));
 168                 }
 169         }
 170
 171         /* BB add processing to set equivalent of mode - e.g. via CreateX with ACLs */
 172         if (oplockEnabled)
 173                 oplock = REQ_OPLOCK;
 174
 175         buf = kmalloc(sizeof(FILE_ALL_INFO),GFP_KERNEL);
 176         if(buf == NULL) {
 177                 kfree(full_path);
 178                 FreeXid(xid);
 179                 return -ENOMEM;
 180         }
 181
 182         rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
 183                          desiredAccess, CREATE_NOT_DIR,
 184                          &fileHandle, &oplock, buf, cifs_sb->local_nls,
 185                          cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 186         if (rc) {
 187                 cFYI(1, ("cifs_create returned 0x%x ", rc));
 188         } else {
 189                 /* If Open reported that we actually created a file
 190                 then we now have to set the mode if possible */
 191                 if ((cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
 192                         (oplock & CIFS_CREATE_ACTION))
 193                         if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 194                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
 195                                         (__u64)current->euid,
 196                                         (__u64)current->egid,
 197                                         0 /* dev */,
 198                                         cifs_sb->local_nls,
 199                                         cifs_sb->mnt_cifs_flags &
 200                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 201                         } else {
 202                                 CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
 203                                         (__u64)-1,
 204                                         (__u64)-1,
 205                                         0 /* dev */,
 206                                         cifs_sb->local_nls,
 207                                         cifs_sb->mnt_cifs_flags &
 208                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 209                         }
 210                 else {
 211                         /* BB implement via Windows security descriptors */
 212                         /* eg CIFSSMBWinSetPerms(xid,pTcon,full_path,mode,-1,-1,local_nls);*/
 213                         /* could set r/o dos attribute if mode & 0222 == 0 */
 214                 }
 215
 216         /* BB server might mask mode so we have to query for Unix case*/
 217                 if (pTcon->ses->capabilities & CAP_UNIX)
 218                         rc = cifs_get_inode_info_unix(&newinode, full_path,
 219                                                  inode->i_sb,xid);
 220                 else {
 221                         rc = cifs_get_inode_info(&newinode, full_path,
 222                                                  buf, inode->i_sb,xid);
 223                         if(newinode)
 224                                 newinode->i_mode = mode;
 225                 }
 226
 227                 if (rc != 0) {
 228                         cFYI(1,("Create worked but get_inode_info failed with rc = %d",
 229                               rc));
 230                 } else {
 231                         direntry->d_op = &cifs_dentry_ops;
 232                         d_instantiate(direntry, newinode);
 233                 }
 234                 if((nd->flags & LOOKUP_OPEN) == FALSE) {
 235                         /* mknod case - do not leave file open */
 236                         CIFSSMBClose(xid, pTcon, fileHandle);
 237                 } else if(newinode) {
 238                         pCifsFile =
 239                            kmalloc(sizeof (struct cifsFileInfo), GFP_KERNEL);
 240
 241                         if(pCifsFile == NULL)
 242                                 goto cifs_create_out;
 243                         memset((char *)pCifsFile, 0,
 244                                sizeof (struct cifsFileInfo));
 245                         pCifsFile->netfid = fileHandle;
 246                         pCifsFile->pid = current->tgid;
 247                         pCifsFile->pInode = newinode;
 248                         pCifsFile->invalidHandle = FALSE;
 249                         pCifsFile->closePend     = FALSE;
 250                         init_MUTEX(&pCifsFile->fh_sem);
 251                         /* set the following in open now
 252                                 pCifsFile->pfile = file; */
 253                         write_lock(&GlobalSMBSeslock);
 254                         list_add(&pCifsFile->tlist,&pTcon->openFileList);
 255                         pCifsInode = CIFS_I(newinode);
 256                         if(pCifsInode) {
 257                                 /* if readable file instance put first in list*/
 258                                 if (write_only == TRUE) {
 259                                         list_add_tail(&pCifsFile->flist,
 260                                                 &pCifsInode->openFileList);
 261                                 } else {
 262                                         list_add(&pCifsFile->flist,
 263                                                 &pCifsInode->openFileList);
 264                                 }
 265                                 if((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
 266                                         pCifsInode->clientCanCacheAll = TRUE;
 267                                         pCifsInode->clientCanCacheRead = TRUE;
 268                                         cFYI(1,("Exclusive Oplock for inode %p",
 269                                                 newinode));
 270                                 } else if((oplock & 0xF) == OPLOCK_READ)
 271                                         pCifsInode->clientCanCacheRead = TRUE;
 272                         }
 273                         write_unlock(&GlobalSMBSeslock);
 274                 }
 275         }
 276 cifs_create_out:
 277         kfree(buf);
 278         kfree(full_path);
 279         FreeXid(xid);
 280         return rc;
 281 }
 282
 283 int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode, dev_t device_number)
 284 {
 285         int rc = -EPERM;
 286         int xid;
 287         struct cifs_sb_info *cifs_sb;
 288         struct cifsTconInfo *pTcon;
 289         char *full_path = NULL;
 290         struct inode * newinode = NULL;
 291
 292         if (!old_valid_dev(device_number))
 293                 return -EINVAL;
 294
 295         xid = GetXid();
 296
 297         cifs_sb = CIFS_SB(inode->i_sb);
 298         pTcon = cifs_sb->tcon;
 299
 300         down(&direntry->d_sb->s_vfs_rename_sem);
 301         full_path = build_path_from_dentry(direntry);
 302         up(&direntry->d_sb->s_vfs_rename_sem);
 303         if(full_path == NULL)
 304                 rc = -ENOMEM;
 305
 306         if (full_path && (pTcon->ses->capabilities & CAP_UNIX)) {
 307                 if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 308                         rc = CIFSSMBUnixSetPerms(xid, pTcon, full_path,
 309                                 mode,(__u64)current->euid,(__u64)current->egid,
 310                                 device_number, cifs_sb->local_nls,
 311                                 cifs_sb->mnt_cifs_flags &
 312                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 313                 } else {
 314                         rc = CIFSSMBUnixSetPerms(xid, pTcon,
 315                                 full_path, mode, (__u64)-1, (__u64)-1,
 316                                 device_number, cifs_sb->local_nls,
 317                                 cifs_sb->mnt_cifs_flags &
 318                                         CIFS_MOUNT_MAP_SPECIAL_CHR);
 319                 }
 320
 321                 if(!rc) {
 322                         rc = cifs_get_inode_info_unix(&newinode, full_path,
 323                                                 inode->i_sb,xid);
 324                         direntry->d_op = &cifs_dentry_ops;
 325                         if(rc == 0)
 326                                 d_instantiate(direntry, newinode);
 327                 }
 328         }
 329
 330         kfree(full_path);
 331         FreeXid(xid);
 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         /* BB Add check of incoming data - e.g. frame not longer than maximum SMB - let server check the namelen BB */
 353
 354         /* check whether path exists */
 355
 356         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
 357         pTcon = cifs_sb->tcon;
 358
 359         /* can not grab the rename sem here since it would
 360         deadlock in the cases (beginning of sys_rename itself)
 361         in which we already have the sb rename sem */
 362         full_path = build_path_from_dentry(direntry);
 363         if(full_path == NULL) {
 364                 FreeXid(xid);
 365                 return ERR_PTR(-ENOMEM);
 366         }
 367
 368         if (direntry->d_inode != NULL) {
 369                 cFYI(1, (" non-NULL inode in lookup"));
 370         } else {
 371                 cFYI(1, (" NULL inode in lookup"));
 372         }
 373         cFYI(1,
 374              (" Full path: %s inode = 0x%p", full_path, direntry->d_inode));
 375
 376         if (pTcon->ses->capabilities & CAP_UNIX)
 377                 rc = cifs_get_inode_info_unix(&newInode, full_path,
 378                                               parent_dir_inode->i_sb,xid);
 379         else
 380                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
 381                                          parent_dir_inode->i_sb,xid);
 382
 383         if ((rc == 0) && (newInode != NULL)) {
 384                 direntry->d_op = &cifs_dentry_ops;
 385                 d_add(direntry, newInode);
 386
 387                 /* since paths are not looked up by component - the parent directories are presumed to be good here */
 388                 renew_parental_timestamps(direntry);
 389
 390         } else if (rc == -ENOENT) {
 391                 rc = 0;
 392                 d_add(direntry, NULL);
 393         } else {
 394                 cERROR(1,("Error 0x%x on cifs_get_inode_info in lookup of %s",
 395                            rc,full_path));
 396                 /* BB special case check for Access Denied - watch security
 397                 exposure of returning dir info implicitly via different rc
 398                 if file exists or not but no access BB */
 399         }
 400
 401         kfree(full_path);
 402         FreeXid(xid);
 403         return ERR_PTR(rc);
 404 }
 405
 406 static int
 407 cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
 408 {
 409         int isValid = 1;
 410
 411 /*      lock_kernel(); *//* surely we do not want to lock the kernel for a whole network round trip which could take seconds */
 412
 413         if (direntry->d_inode) {
 414                 if (cifs_revalidate(direntry)) {
 415                         /* unlock_kernel(); */
 416                         return 0;
 417                 }
 418         } else {
 419                 cFYI(1,
 420                      ("In cifs_d_revalidate with no inode but name = %s and dentry 0x%p",
 421                       direntry->d_name.name, direntry));
 422         }
 423
 424 /*    unlock_kernel(); */
 425
 426         return isValid;
 427 }
 428
 429 /* static int cifs_d_delete(struct dentry *direntry)
 430 {
 431         int rc = 0;
 432
 433         cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));
 434
 435         return rc;
 436 }     */
 437
 438 struct dentry_operations cifs_dentry_ops = {
 439         .d_revalidate = cifs_d_revalidate,
 440 /* d_delete:       cifs_d_delete,       *//* not needed except for debugging */
 441         /* no need for d_hash, d_compare, d_release, d_iput ... yet. BB confirm this BB */
 442 };