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));   /* BB for DFS case should stop at the root of share which could be lower than root of this mount due to implicit dfs connections */
  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         for (temp = direntry; !IS_ROOT(temp);) {
  53                 namelen += (1 + temp->d_name.len);
  54                 temp = temp->d_parent;
  55         }
  56         namelen += 1;           /* allow for trailing null */
  57         full_path = kmalloc(namelen, GFP_KERNEL);
  58         namelen--;
  59         full_path[namelen] = 0; /* trailing null */
  60         for (temp = direntry; !IS_ROOT(temp);) {
  61                 namelen -= 1 + temp->d_name.len;
  62                 if (namelen < 0) {
  63                         break;
  64                 } else {
  65                         full_path[namelen] = '\\';
  66                         strncpy(full_path + namelen + 1, temp->d_name.name,
  67                                 temp->d_name.len);
  68                         cFYI(0, (" name: %s ", full_path + namelen));
  69                 }
  70                 temp = temp->d_parent;
  71         }
  72         if (namelen != 0)
  73                 cERROR(1,
  74                        ("We did not end path lookup where we expected namelen is %d",
  75                         namelen));
  76
  77         return full_path;
  78 }
  79
  80 char *
  81 build_wildcard_path_from_dentry(struct dentry *direntry)
  82 {
  83         struct dentry *temp;
  84         int namelen = 0;
  85         char *full_path;
  86
  87         for (temp = direntry; !IS_ROOT(temp);) {
  88                 namelen += (1 + temp->d_name.len);
  89                 temp = temp->d_parent;
  90         }
  91         namelen += 3;           /* allow for trailing null and wildcard (slash and *) */
  92         full_path = kmalloc(namelen, GFP_KERNEL);
  93         namelen--;
  94         full_path[namelen] = 0; /* trailing null */
  95         namelen--;
  96         full_path[namelen] = '*';
  97         namelen--;
  98         full_path[namelen] = '\\';
  99
 100         for (temp = direntry; !IS_ROOT(temp);) {
 101                 namelen -= 1 + temp->d_name.len;
 102                 if (namelen < 0) {
 103                         break;
 104                 } else {
 105                         full_path[namelen] = '\\';
 106                         strncpy(full_path + namelen + 1, temp->d_name.name,
 107                                 temp->d_name.len);
 108                 }
 109                 temp = temp->d_parent;
 110         }
 111         if (namelen != 0)
 112                 cERROR(1,
 113                        ("We did not end path lookup where we expected namelen is %d",
 114                         namelen));
 115
 116         return full_path;
 117 }
 118
 119 /* Inode operations in similar order to how they appear in the Linux file fs.h */
 120
 121 int
 122 cifs_create(struct inode *inode, struct dentry *direntry, int mode,
 123                 struct nameidata *nd)
 124 {
 125         int rc = -ENOENT;
 126         int xid;
 127         int oplock = 0;
 128         int desiredAccess = GENERIC_READ | GENERIC_WRITE;
 129         __u16 fileHandle;
 130         struct cifs_sb_info *cifs_sb;
 131         struct cifsTconInfo *pTcon;
 132         char *full_path = NULL;
 133         FILE_ALL_INFO * buf = NULL;
 134         struct inode *newinode = NULL;
 135         struct cifsFileInfo * pCifsFile = NULL;
 136         struct cifsInodeInfo * pCifsInode;
 137         int disposition = FILE_OVERWRITE_IF;
 138
 139         xid = GetXid();
 140
 141         cifs_sb = CIFS_SB(inode->i_sb);
 142         pTcon = cifs_sb->tcon;
 143
 144         full_path = build_path_from_dentry(direntry);
 145
 146         if(nd) {
 147                 cFYI(1,("In create for inode %p dentry->inode %p nd flags = 0x%x for %s",inode, direntry->d_inode, nd->flags,full_path));
 148
 149                 if ((nd->intent.open.flags & O_ACCMODE) == O_RDONLY)
 150                         desiredAccess = GENERIC_READ;
 151                 else if ((nd->intent.open.flags & O_ACCMODE) == O_WRONLY)
 152                         desiredAccess = GENERIC_WRITE;
 153                 else if ((nd->intent.open.flags & O_ACCMODE) == O_RDWR) {
 154                         /* GENERIC_ALL is too much permission to request */
 155                         /* can cause unnecessary access denied on create */
 156                         /* desiredAccess = GENERIC_ALL; */
 157                         desiredAccess = GENERIC_READ | GENERIC_WRITE;
 158                 }
 159
 160                 if((nd->intent.open.flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 161                         disposition = FILE_CREATE;
 162                 else if((nd->intent.open.flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
 163                         disposition = FILE_OVERWRITE_IF;
 164                 else if((nd->intent.open.flags & 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         rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
 177                          desiredAccess, CREATE_NOT_DIR,
 178                          &fileHandle, &oplock, buf, cifs_sb->local_nls);
 179         if (rc) {
 180                 cFYI(1, ("cifs_create returned 0x%x ", rc));
 181         } else {
 182                 /* If Open reported that we actually created a file
 183                 then we now have to set the mode if possible */
 184                 if ((cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
 185                         (oplock & CIFS_CREATE_ACTION))
 186                         CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
 187                                         (__u64)-1,
 188                                         (__u64)-1,
 189                                         0 /* dev */,
 190                                         cifs_sb->local_nls);
 191                 else {
 192                         /* BB implement via Windows security descriptors */
 193                         /* eg CIFSSMBWinSetPerms(xid,pTcon,full_path,mode,-1,-1,local_nls);*/
 194                         /* could set r/o dos attribute if mode & 0222 == 0 */
 195                 }
 196
 197         /* BB server might mask mode so we have to query for Unix case*/
 198                 if (pTcon->ses->capabilities & CAP_UNIX)
 199                         rc = cifs_get_inode_info_unix(&newinode, full_path,
 200                                                  inode->i_sb);
 201                 else {
 202                         rc = cifs_get_inode_info(&newinode, full_path,
 203                                                  buf, inode->i_sb);
 204                         if(newinode)
 205                                 newinode->i_mode = mode;
 206                 }
 207
 208                 if (rc != 0) {
 209                         cFYI(1,("Create worked but get_inode_info failed with rc = %d",
 210                               rc));
 211                 } else {
 212                         direntry->d_op = &cifs_dentry_ops;
 213                         d_instantiate(direntry, newinode);
 214                 }
 215                 if((nd->flags & LOOKUP_OPEN) == FALSE) {
 216                         /* mknod case - do not leave file open */
 217                         CIFSSMBClose(xid, pTcon, fileHandle);
 218                 } else if(newinode) {
 219                         pCifsFile = (struct cifsFileInfo *)
 220                            kmalloc(sizeof (struct cifsFileInfo), GFP_KERNEL);
 221
 222                         if (pCifsFile) {
 223                                 memset((char *)pCifsFile, 0,
 224                                        sizeof (struct cifsFileInfo));
 225                                 pCifsFile->netfid = fileHandle;
 226                                 pCifsFile->pid = current->tgid;
 227                                 pCifsFile->pInode = newinode;
 228                                 pCifsFile->invalidHandle = FALSE;
 229                                 pCifsFile->closePend     = FALSE;
 230                                 init_MUTEX(&pCifsFile->fh_sem);
 231                                 /* pCifsFile->pfile = file; */ /* put in at open time */
 232                                 write_lock(&GlobalSMBSeslock);
 233                                 list_add(&pCifsFile->tlist,&pTcon->openFileList);
 234                                 pCifsInode = CIFS_I(newinode);
 235                                 if(pCifsInode) {
 236                                         list_add(&pCifsFile->flist,&pCifsInode->openFileList);
 237                                         if((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
 238                                                 pCifsInode->clientCanCacheAll = TRUE;
 239                                                 pCifsInode->clientCanCacheRead = TRUE;
 240                                                 cFYI(1,("Exclusive Oplock granted on inode %p",newinode));
 241                                         } else if((oplock & 0xF) == OPLOCK_READ)
 242                                                 pCifsInode->clientCanCacheRead = TRUE;
 243                                 }
 244                                 write_unlock(&GlobalSMBSeslock);
 245                         }
 246                 }
 247         }
 248
 249         if (buf)
 250             kfree(buf);
 251         if (full_path)
 252             kfree(full_path);
 253         FreeXid(xid);
 254
 255         return rc;
 256 }
 257
 258 int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode, dev_t device_number)
 259 {
 260         int rc = -EPERM;
 261         int xid;
 262         struct cifs_sb_info *cifs_sb;
 263         struct cifsTconInfo *pTcon;
 264         char *full_path = NULL;
 265         struct inode * newinode = NULL;
 266
 267         if (!old_valid_dev(device_number))
 268                 return -EINVAL;
 269
 270         xid = GetXid();
 271
 272         cifs_sb = CIFS_SB(inode->i_sb);
 273         pTcon = cifs_sb->tcon;
 274
 275         full_path = build_path_from_dentry(direntry);
 276
 277         if (pTcon->ses->capabilities & CAP_UNIX) {
 278                 rc = CIFSSMBUnixSetPerms(xid, pTcon,
 279                         full_path, mode, current->euid, current->egid,
 280                         device_number, cifs_sb->local_nls);
 281                 if(!rc) {
 282                         rc = cifs_get_inode_info_unix(&newinode, full_path,
 283                                                 inode->i_sb);
 284                         direntry->d_op = &cifs_dentry_ops;
 285                         if(rc == 0)
 286                                 d_instantiate(direntry, newinode);
 287                 }
 288         }
 289
 290         if (full_path)
 291                 kfree(full_path);
 292         FreeXid(xid);
 293
 294         return rc;
 295 }
 296
 297
 298 struct dentry *
 299 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, struct nameidata *nd)
 300 {
 301         int rc, xid;
 302         struct cifs_sb_info *cifs_sb;
 303         struct cifsTconInfo *pTcon;
 304         struct inode *newInode = NULL;
 305         char *full_path = NULL;
 306
 307         xid = GetXid();
 308
 309         cFYI(1,
 310              (" parent inode = 0x%p name is: %s and dentry = 0x%p",
 311               parent_dir_inode, direntry->d_name.name, direntry));
 312
 313         if(nd) {  /* BB removeme */
 314                 cFYI(1,("In lookup nd flags 0x%x open intent flags 0x%x",nd->flags,nd->intent.open.flags));
 315         } /* BB removeme BB */
 316         /* BB Add check of incoming data - e.g. frame not longer than maximum SMB - let server check the namelen BB */
 317
 318         /* check whether path exists */
 319
 320         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
 321         pTcon = cifs_sb->tcon;
 322
 323         full_path = build_path_from_dentry(direntry);
 324         if (direntry->d_inode != NULL) {
 325                 cFYI(1, (" non-NULL inode in lookup"));
 326         } else {
 327                 cFYI(1, (" NULL inode in lookup"));
 328         }
 329         cFYI(1,
 330              (" Full path: %s inode = 0x%p", full_path, direntry->d_inode));
 331
 332         if (pTcon->ses->capabilities & CAP_UNIX)
 333                 rc = cifs_get_inode_info_unix(&newInode, full_path,
 334                                               parent_dir_inode->i_sb);
 335         else
 336                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
 337                                          parent_dir_inode->i_sb);
 338
 339         if ((rc == 0) && (newInode != NULL)) {
 340                 direntry->d_op = &cifs_dentry_ops;
 341                 d_add(direntry, newInode);
 342
 343                 /* since paths are not looked up by component - the parent directories are presumed to be good here */
 344                 renew_parental_timestamps(direntry);
 345
 346         } else if (rc == -ENOENT) {
 347                 rc = 0;
 348                 d_add(direntry, NULL);
 349         } else {
 350                 cERROR(1,
 351                        ("Error 0x%x or (%d decimal) on cifs_get_inode_info in lookup",
 352                         rc, rc));
 353                 /* BB special case check for Access Denied - watch security exposure of returning dir info implicitly via different rc if file exists or not but no access BB */
 354         }
 355
 356         if (full_path)
 357                 kfree(full_path);
 358         FreeXid(xid);
 359         return ERR_PTR(rc);
 360 }
 361
 362 int
 363 cifs_dir_open(struct inode *inode, struct file *file)
 364 {                               /* NB: currently unused since searches are opened in readdir */
 365         int rc = 0;
 366         int xid;
 367         struct cifs_sb_info *cifs_sb;
 368         struct cifsTconInfo *pTcon;
 369         char *full_path = NULL;
 370
 371         xid = GetXid();
 372
 373         cifs_sb = CIFS_SB(inode->i_sb);
 374         pTcon = cifs_sb->tcon;
 375
 376         full_path = build_wildcard_path_from_dentry(file->f_dentry);
 377
 378         cFYI(1, (" inode = 0x%p and full path is %s", inode, full_path));
 379
 380         if (full_path)
 381                 kfree(full_path);
 382         FreeXid(xid);
 383         return rc;
 384 }
 385
 386 static int
 387 cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
 388 {
 389         int isValid = 1;
 390
 391 /*      lock_kernel(); *//* surely we do not want to lock the kernel for a whole network round trip which could take seconds */
 392
 393         if (direntry->d_inode) {
 394                 if (cifs_revalidate(direntry)) {
 395                         /* unlock_kernel(); */
 396                         return 0;
 397                 }
 398         } else {
 399                 cFYI(1,
 400                      ("In cifs_d_revalidate with no inode but name = %s and dentry 0x%p",
 401                       direntry->d_name.name, direntry));
 402         }
 403
 404 /*    unlock_kernel(); */
 405
 406         return isValid;
 407 }
 408
 409 /* static int cifs_d_delete(struct dentry *direntry)
 410 {
 411         int rc = 0;
 412
 413         cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));
 414
 415         return rc;
 416 }     */
 417
 418 struct dentry_operations cifs_dentry_ops = {
 419         .d_revalidate = cifs_d_revalidate,
 420 /* d_delete:       cifs_d_delete,       *//* not needed except for debugging */
 421         /* no need for d_hash, d_compare, d_release, d_iput ... yet. BB confirm this BB */
 422 };