fs/smbfs/dir.c

   1 /*
   2  *  dir.c
   3  *
   4  *  Copyright (C) 1995, 1996 by Paal-Kr. Engstad and Volker Lendecke
   5  *  Copyright (C) 1997 by Volker Lendecke
   6  *
   7  *  Please add a note about your changes to smbfs in the ChangeLog file.
   8  */
   9
  10 #include <linux/time.h>
  11 #include <linux/errno.h>
  12 #include <linux/kernel.h>
  13 #include <linux/smp_lock.h>
  14 #include <linux/ctype.h>
  15 #include <linux/net.h>
  16 #include <linux/sched.h>
  17
  18 #include <linux/smb_fs.h>
  19 #include <linux/smb_mount.h>
  20 #include <linux/smbno.h>
  21
  22 #include "smb_debug.h"
  23 #include "proto.h"
  24
  25 static int smb_readdir(struct file *, void *, filldir_t);
  26 static int smb_dir_open(struct inode *, struct file *);
  27
  28 static struct dentry *smb_lookup(struct inode *, struct dentry *, struct nameidata *);
  29 static int smb_create(struct inode *, struct dentry *, int, struct nameidata *);
  30 static int smb_mkdir(struct inode *, struct dentry *, int);
  31 static int smb_rmdir(struct inode *, struct dentry *);
  32 static int smb_unlink(struct inode *, struct dentry *);
  33 static int smb_rename(struct inode *, struct dentry *,
  34                       struct inode *, struct dentry *);
  35 static int smb_make_node(struct inode *,struct dentry *,int,dev_t);
  36 static int smb_link(struct dentry *, struct inode *, struct dentry *);
  37
  38 const struct file_operations smb_dir_operations =
  39 {
  40         .read           = generic_read_dir,
  41         .readdir        = smb_readdir,
  42         .ioctl          = smb_ioctl,
  43         .open           = smb_dir_open,
  44 };
  45
  46 const struct inode_operations smb_dir_inode_operations =
  47 {
  48         .create         = smb_create,
  49         .lookup         = smb_lookup,
  50         .unlink         = smb_unlink,
  51         .mkdir          = smb_mkdir,
  52         .rmdir          = smb_rmdir,
  53         .rename         = smb_rename,
  54         .getattr        = smb_getattr,
  55         .setattr        = smb_notify_change,
  56 };
  57
  58 const struct inode_operations smb_dir_inode_operations_unix =
  59 {
  60         .create         = smb_create,
  61         .lookup         = smb_lookup,
  62         .unlink         = smb_unlink,
  63         .mkdir          = smb_mkdir,
  64         .rmdir          = smb_rmdir,
  65         .rename         = smb_rename,
  66         .getattr        = smb_getattr,
  67         .setattr        = smb_notify_change,
  68         .symlink        = smb_symlink,
  69         .mknod          = smb_make_node,
  70         .link           = smb_link,
  71 };
  72
  73 /*
  74  * Read a directory, using filldir to fill the dirent memory.
  75  * smb_proc_readdir does the actual reading from the smb server.
  76  *
  77  * The cache code is almost directly taken from ncpfs
  78  */
  79 static int
  80 smb_readdir(struct file *filp, void *dirent, filldir_t filldir)
  81 {
  82         struct dentry *dentry = filp->f_path.dentry;
  83         struct inode *dir = dentry->d_inode;
  84         struct smb_sb_info *server = server_from_dentry(dentry);
  85         union  smb_dir_cache *cache = NULL;
  86         struct smb_cache_control ctl;
  87         struct page *page = NULL;
  88         int result;
  89
  90         ctl.page  = NULL;
  91         ctl.cache = NULL;
  92
  93         VERBOSE("reading %s/%s, f_pos=%d\n",
  94                 DENTRY_PATH(dentry),  (int) filp->f_pos);
  95
  96         result = 0;
  97
  98         lock_kernel();
  99
 100         switch ((unsigned int) filp->f_pos) {
 101         case 0:
 102                 if (filldir(dirent, ".", 1, 0, dir->i_ino, DT_DIR) < 0)
 103                         goto out;
 104                 filp->f_pos = 1;
 105                 /* fallthrough */
 106         case 1:
 107                 if (filldir(dirent, "..", 2, 1, parent_ino(dentry), DT_DIR) < 0)
 108                         goto out;
 109                 filp->f_pos = 2;
 110         }
 111
 112         /*
 113          * Make sure our inode is up-to-date.
 114          */
 115         result = smb_revalidate_inode(dentry);
 116         if (result)
 117                 goto out;
 118
 119
 120         page = grab_cache_page(&dir->i_data, 0);
 121         if (!page)
 122                 goto read_really;
 123
 124         ctl.cache = cache = kmap(page);
 125         ctl.head  = cache->head;
 126
 127         if (!PageUptodate(page) || !ctl.head.eof) {
 128                 VERBOSE("%s/%s, page uptodate=%d, eof=%d\n",
 129                          DENTRY_PATH(dentry), PageUptodate(page),ctl.head.eof);
 130                 goto init_cache;
 131         }
 132
 133         if (filp->f_pos == 2) {
 134                 if (jiffies - ctl.head.time >= SMB_MAX_AGE(server))
 135                         goto init_cache;
 136
 137                 /*
 138                  * N.B. ncpfs checks mtime of dentry too here, we don't.
 139                  *   1. common smb servers do not update mtime on dir changes
 140                  *   2. it requires an extra smb request
 141                  *      (revalidate has the same timeout as ctl.head.time)
 142                  *
 143                  * Instead smbfs invalidates its own cache on local changes
 144                  * and remote changes are not seen until timeout.
 145                  */
 146         }
 147
 148         if (filp->f_pos > ctl.head.end)
 149                 goto finished;
 150
 151         ctl.fpos = filp->f_pos + (SMB_DIRCACHE_START - 2);
 152         ctl.ofs  = ctl.fpos / SMB_DIRCACHE_SIZE;
 153         ctl.idx  = ctl.fpos % SMB_DIRCACHE_SIZE;
 154
 155         for (;;) {
 156                 if (ctl.ofs != 0) {
 157                         ctl.page = find_lock_page(&dir->i_data, ctl.ofs);
 158                         if (!ctl.page)
 159                                 goto invalid_cache;
 160                         ctl.cache = kmap(ctl.page);
 161                         if (!PageUptodate(ctl.page))
 162                                 goto invalid_cache;
 163                 }
 164                 while (ctl.idx < SMB_DIRCACHE_SIZE) {
 165                         struct dentry *dent;
 166                         int res;
 167
 168                         dent = smb_dget_fpos(ctl.cache->dentry[ctl.idx],
 169                                              dentry, filp->f_pos);
 170                         if (!dent)
 171                                 goto invalid_cache;
 172
 173                         res = filldir(dirent, dent->d_name.name,
 174                                       dent->d_name.len, filp->f_pos,
 175                                       dent->d_inode->i_ino, DT_UNKNOWN);
 176                         dput(dent);
 177                         if (res)
 178                                 goto finished;
 179                         filp->f_pos += 1;
 180                         ctl.idx += 1;
 181                         if (filp->f_pos > ctl.head.end)
 182                                 goto finished;
 183                 }
 184                 if (ctl.page) {
 185                         kunmap(ctl.page);
 186                         SetPageUptodate(ctl.page);
 187                         unlock_page(ctl.page);
 188                         page_cache_release(ctl.page);
 189                         ctl.page = NULL;
 190                 }
 191                 ctl.idx  = 0;
 192                 ctl.ofs += 1;
 193         }
 194 invalid_cache:
 195         if (ctl.page) {
 196                 kunmap(ctl.page);
 197                 unlock_page(ctl.page);
 198                 page_cache_release(ctl.page);
 199                 ctl.page = NULL;
 200         }
 201         ctl.cache = cache;
 202 init_cache:
 203         smb_invalidate_dircache_entries(dentry);
 204         ctl.head.time = jiffies;
 205         ctl.head.eof = 0;
 206         ctl.fpos = 2;
 207         ctl.ofs = 0;
 208         ctl.idx = SMB_DIRCACHE_START;
 209         ctl.filled = 0;
 210         ctl.valid  = 1;
 211 read_really:
 212         result = server->ops->readdir(filp, dirent, filldir, &ctl);
 213         if (result == -ERESTARTSYS && page)
 214                 ClearPageUptodate(page);
 215         if (ctl.idx == -1)
 216                 goto invalid_cache;     /* retry */
 217         ctl.head.end = ctl.fpos - 1;
 218         ctl.head.eof = ctl.valid;
 219 finished:
 220         if (page) {
 221                 cache->head = ctl.head;
 222                 kunmap(page);
 223                 if (result != -ERESTARTSYS)
 224                         SetPageUptodate(page);
 225                 unlock_page(page);
 226                 page_cache_release(page);
 227         }
 228         if (ctl.page) {
 229                 kunmap(ctl.page);
 230                 SetPageUptodate(ctl.page);
 231                 unlock_page(ctl.page);
 232                 page_cache_release(ctl.page);
 233         }
 234 out:
 235         unlock_kernel();
 236         return result;
 237 }
 238
 239 static int
 240 smb_dir_open(struct inode *dir, struct file *file)
 241 {
 242         struct dentry *dentry = file->f_path.dentry;
 243         struct smb_sb_info *server;
 244         int error = 0;
 245
 246         VERBOSE("(%s/%s)\n", dentry->d_parent->d_name.name,
 247                 file->f_path.dentry->d_name.name);
 248
 249         /*
 250          * Directory timestamps in the core protocol aren't updated
 251          * when a file is added, so we give them a very short TTL.
 252          */
 253         lock_kernel();
 254         server = server_from_dentry(dentry);
 255         if (server->opt.protocol < SMB_PROTOCOL_LANMAN2) {
 256                 unsigned long age = jiffies - SMB_I(dir)->oldmtime;
 257                 if (age > 2*HZ)
 258                         smb_invalid_dir_cache(dir);
 259         }
 260
 261         /*
 262          * Note: in order to allow the smbmount process to open the
 263          * mount point, we only revalidate if the connection is valid or
 264          * if the process is trying to access something other than the root.
 265          */
 266         if (server->state == CONN_VALID || !IS_ROOT(dentry))
 267                 error = smb_revalidate_inode(dentry);
 268         unlock_kernel();
 269         return error;
 270 }
 271
 272 /*
 273  * Dentry operations routines
 274  */
 275 static int smb_lookup_validate(struct dentry *, struct nameidata *);
 276 static int smb_hash_dentry(struct dentry *, struct qstr *);
 277 static int smb_compare_dentry(struct dentry *, struct qstr *, struct qstr *);
 278 static int smb_delete_dentry(struct dentry *);
 279
 280 static const struct dentry_operations smbfs_dentry_operations =
 281 {
 282         .d_revalidate   = smb_lookup_validate,
 283         .d_hash         = smb_hash_dentry,
 284         .d_compare      = smb_compare_dentry,
 285         .d_delete       = smb_delete_dentry,
 286 };
 287
 288 static const struct dentry_operations smbfs_dentry_operations_case =
 289 {
 290         .d_revalidate   = smb_lookup_validate,
 291         .d_delete       = smb_delete_dentry,
 292 };
 293
 294
 295 /*
 296  * This is the callback when the dcache has a lookup hit.
 297  */
 298 static int
 299 smb_lookup_validate(struct dentry * dentry, struct nameidata *nd)
 300 {
 301         struct smb_sb_info *server = server_from_dentry(dentry);
 302         struct inode * inode = dentry->d_inode;
 303         unsigned long age = jiffies - dentry->d_time;
 304         int valid;
 305
 306         /*
 307          * The default validation is based on dentry age:
 308          * we believe in dentries for a few seconds.  (But each
 309          * successful server lookup renews the timestamp.)
 310          */
 311         valid = (age <= SMB_MAX_AGE(server));
 312 #ifdef SMBFS_DEBUG_VERBOSE
 313         if (!valid)
 314                 VERBOSE("%s/%s not valid, age=%lu\n",
 315                         DENTRY_PATH(dentry), age);
 316 #endif
 317
 318         if (inode) {
 319                 lock_kernel();
 320                 if (is_bad_inode(inode)) {
 321                         PARANOIA("%s/%s has dud inode\n", DENTRY_PATH(dentry));
 322                         valid = 0;
 323                 } else if (!valid)
 324                         valid = (smb_revalidate_inode(dentry) == 0);
 325                 unlock_kernel();
 326         } else {
 327                 /*
 328                  * What should we do for negative dentries?
 329                  */
 330         }
 331         return valid;
 332 }
 333
 334 static int
 335 smb_hash_dentry(struct dentry *dir, struct qstr *this)
 336 {
 337         unsigned long hash;
 338         int i;
 339
 340         hash = init_name_hash();
 341         for (i=0; i < this->len ; i++)
 342                 hash = partial_name_hash(tolower(this->name[i]), hash);
 343         this->hash = end_name_hash(hash);
 344
 345         return 0;
 346 }
 347
 348 static int
 349 smb_compare_dentry(struct dentry *dir, struct qstr *a, struct qstr *b)
 350 {
 351         int i, result = 1;
 352
 353         if (a->len != b->len)
 354                 goto out;
 355         for (i=0; i < a->len; i++) {
 356                 if (tolower(a->name[i]) != tolower(b->name[i]))
 357                         goto out;
 358         }
 359         result = 0;
 360 out:
 361         return result;
 362 }
 363
 364 /*
 365  * This is the callback from dput() when d_count is going to 0.
 366  * We use this to unhash dentries with bad inodes.
 367  */
 368 static int
 369 smb_delete_dentry(struct dentry * dentry)
 370 {
 371         if (dentry->d_inode) {
 372                 if (is_bad_inode(dentry->d_inode)) {
 373                         PARANOIA("bad inode, unhashing %s/%s\n",
 374                                  DENTRY_PATH(dentry));
 375                         return 1;
 376                 }
 377         } else {
 378                 /* N.B. Unhash negative dentries? */
 379         }
 380         return 0;
 381 }
 382
 383 /*
 384  * Initialize a new dentry
 385  */
 386 void
 387 smb_new_dentry(struct dentry *dentry)
 388 {
 389         struct smb_sb_info *server = server_from_dentry(dentry);
 390
 391         if (server->mnt->flags & SMB_MOUNT_CASE)
 392                 dentry->d_op = &smbfs_dentry_operations_case;
 393         else
 394                 dentry->d_op = &smbfs_dentry_operations;
 395         dentry->d_time = jiffies;
 396 }
 397
 398
 399 /*
 400  * Whenever a lookup succeeds, we know the parent directories
 401  * are all valid, so we want to update the dentry timestamps.
 402  * N.B. Move this to dcache?
 403  */
 404 void
 405 smb_renew_times(struct dentry * dentry)
 406 {
 407         dget(dentry);
 408         spin_lock(&dentry->d_lock);
 409         for (;;) {
 410                 struct dentry *parent;
 411
 412                 dentry->d_time = jiffies;
 413                 if (IS_ROOT(dentry))
 414                         break;
 415                 parent = dentry->d_parent;
 416                 dget(parent);
 417                 spin_unlock(&dentry->d_lock);
 418                 dput(dentry);
 419                 dentry = parent;
 420                 spin_lock(&dentry->d_lock);
 421         }
 422         spin_unlock(&dentry->d_lock);
 423         dput(dentry);
 424 }
 425
 426 static struct dentry *
 427 smb_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
 428 {
 429         struct smb_fattr finfo;
 430         struct inode *inode;
 431         int error;
 432         struct smb_sb_info *server;
 433
 434         error = -ENAMETOOLONG;
 435         if (dentry->d_name.len > SMB_MAXNAMELEN)
 436                 goto out;
 437
 438         /* Do not allow lookup of names with backslashes in */
 439         error = -EINVAL;
 440         if (memchr(dentry->d_name.name, '\\', dentry->d_name.len))
 441                 goto out;
 442
 443         lock_kernel();
 444         error = smb_proc_getattr(dentry, &finfo);
 445 #ifdef SMBFS_PARANOIA
 446         if (error && error != -ENOENT)
 447                 PARANOIA("find %s/%s failed, error=%d\n",
 448                          DENTRY_PATH(dentry), error);
 449 #endif
 450
 451         inode = NULL;
 452         if (error == -ENOENT)
 453                 goto add_entry;
 454         if (!error) {
 455                 error = -EACCES;
 456                 finfo.f_ino = iunique(dentry->d_sb, 2);
 457                 inode = smb_iget(dir->i_sb, &finfo);
 458                 if (inode) {
 459         add_entry:
 460                         server = server_from_dentry(dentry);
 461                         if (server->mnt->flags & SMB_MOUNT_CASE)
 462                                 dentry->d_op = &smbfs_dentry_operations_case;
 463                         else
 464                                 dentry->d_op = &smbfs_dentry_operations;
 465
 466                         d_add(dentry, inode);
 467                         smb_renew_times(dentry);
 468                         error = 0;
 469                 }
 470         }
 471         unlock_kernel();
 472 out:
 473         return ERR_PTR(error);
 474 }
 475
 476 /*
 477  * This code is common to all routines creating a new inode.
 478  */
 479 static int
 480 smb_instantiate(struct dentry *dentry, __u16 fileid, int have_id)
 481 {
 482         struct smb_sb_info *server = server_from_dentry(dentry);
 483         struct inode *inode;
 484         int error;
 485         struct smb_fattr fattr;
 486
 487         VERBOSE("file %s/%s, fileid=%u\n", DENTRY_PATH(dentry), fileid);
 488
 489         error = smb_proc_getattr(dentry, &fattr);
 490         if (error)
 491                 goto out_close;
 492
 493         smb_renew_times(dentry);
 494         fattr.f_ino = iunique(dentry->d_sb, 2);
 495         inode = smb_iget(dentry->d_sb, &fattr);
 496         if (!inode)
 497                 goto out_no_inode;
 498
 499         if (have_id) {
 500                 struct smb_inode_info *ei = SMB_I(inode);
 501                 ei->fileid = fileid;
 502                 ei->access = SMB_O_RDWR;
 503                 ei->open = server->generation;
 504         }
 505         d_instantiate(dentry, inode);
 506 out:
 507         return error;
 508
 509 out_no_inode:
 510         error = -EACCES;
 511 out_close:
 512         if (have_id) {
 513                 PARANOIA("%s/%s failed, error=%d, closing %u\n",
 514                          DENTRY_PATH(dentry), error, fileid);
 515                 smb_close_fileid(dentry, fileid);
 516         }
 517         goto out;
 518 }
 519
 520 /* N.B. How should the mode argument be used? */
 521 static int
 522 smb_create(struct inode *dir, struct dentry *dentry, int mode,
 523                 struct nameidata *nd)
 524 {
 525         struct smb_sb_info *server = server_from_dentry(dentry);
 526         __u16 fileid;
 527         int error;
 528         struct iattr attr;
 529
 530         VERBOSE("creating %s/%s, mode=%d\n", DENTRY_PATH(dentry), mode);
 531
 532         lock_kernel();
 533         smb_invalid_dir_cache(dir);
 534         error = smb_proc_create(dentry, 0, get_seconds(), &fileid);
 535         if (!error) {
 536                 if (server->opt.capabilities & SMB_CAP_UNIX) {
 537                         /* Set attributes for new file */
 538                         attr.ia_valid = ATTR_MODE;
 539                         attr.ia_mode = mode;
 540                         error = smb_proc_setattr_unix(dentry, &attr, 0, 0);
 541                 }
 542                 error = smb_instantiate(dentry, fileid, 1);
 543         } else {
 544                 PARANOIA("%s/%s failed, error=%d\n",
 545                          DENTRY_PATH(dentry), error);
 546         }
 547         unlock_kernel();
 548         return error;
 549 }
 550
 551 /* N.B. How should the mode argument be used? */
 552 static int
 553 smb_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 554 {
 555         struct smb_sb_info *server = server_from_dentry(dentry);
 556         int error;
 557         struct iattr attr;
 558
 559         lock_kernel();
 560         smb_invalid_dir_cache(dir);
 561         error = smb_proc_mkdir(dentry);
 562         if (!error) {
 563                 if (server->opt.capabilities & SMB_CAP_UNIX) {
 564                         /* Set attributes for new directory */
 565                         attr.ia_valid = ATTR_MODE;
 566                         attr.ia_mode = mode;
 567                         error = smb_proc_setattr_unix(dentry, &attr, 0, 0);
 568                 }
 569                 error = smb_instantiate(dentry, 0, 0);
 570         }
 571         unlock_kernel();
 572         return error;
 573 }
 574
 575 static int
 576 smb_rmdir(struct inode *dir, struct dentry *dentry)
 577 {
 578         struct inode *inode = dentry->d_inode;
 579         int error;
 580
 581         /*
 582          * Close the directory if it's open.
 583          */
 584         lock_kernel();
 585         smb_close(inode);
 586
 587         /*
 588          * Check that nobody else is using the directory..
 589          */
 590         error = -EBUSY;
 591         if (!d_unhashed(dentry))
 592                 goto out;
 593
 594         smb_invalid_dir_cache(dir);
 595         error = smb_proc_rmdir(dentry);
 596
 597 out:
 598         unlock_kernel();
 599         return error;
 600 }
 601
 602 static int
 603 smb_unlink(struct inode *dir, struct dentry *dentry)
 604 {
 605         int error;
 606
 607         /*
 608          * Close the file if it's open.
 609          */
 610         lock_kernel();
 611         smb_close(dentry->d_inode);
 612
 613         smb_invalid_dir_cache(dir);
 614         error = smb_proc_unlink(dentry);
 615         if (!error)
 616                 smb_renew_times(dentry);
 617         unlock_kernel();
 618         return error;
 619 }
 620
 621 static int
 622 smb_rename(struct inode *old_dir, struct dentry *old_dentry,
 623            struct inode *new_dir, struct dentry *new_dentry)
 624 {
 625         int error;
 626
 627         /*
 628          * Close any open files, and check whether to delete the
 629          * target before attempting the rename.
 630          */
 631         lock_kernel();
 632         if (old_dentry->d_inode)
 633                 smb_close(old_dentry->d_inode);
 634         if (new_dentry->d_inode) {
 635                 smb_close(new_dentry->d_inode);
 636                 error = smb_proc_unlink(new_dentry);
 637                 if (error) {
 638                         VERBOSE("unlink %s/%s, error=%d\n",
 639                                 DENTRY_PATH(new_dentry), error);
 640                         goto out;
 641                 }
 642                 /* FIXME */
 643                 d_delete(new_dentry);
 644         }
 645
 646         smb_invalid_dir_cache(old_dir);
 647         smb_invalid_dir_cache(new_dir);
 648         error = smb_proc_mv(old_dentry, new_dentry);
 649         if (!error) {
 650                 smb_renew_times(old_dentry);
 651                 smb_renew_times(new_dentry);
 652         }
 653 out:
 654         unlock_kernel();
 655         return error;
 656 }
 657
 658 /*
 659  * FIXME: samba servers won't let you create device nodes unless uid/gid
 660  * matches the connection credentials (and we don't know which those are ...)
 661  */
 662 static int
 663 smb_make_node(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
 664 {
 665         int error;
 666         struct iattr attr;
 667
 668         attr.ia_valid = ATTR_MODE | ATTR_UID | ATTR_GID;
 669         attr.ia_mode = mode;
 670         current_euid_egid(&attr.ia_uid, &attr.ia_gid);
 671
 672         if (!new_valid_dev(dev))
 673                 return -EINVAL;
 674
 675         smb_invalid_dir_cache(dir);
 676         error = smb_proc_setattr_unix(dentry, &attr, MAJOR(dev), MINOR(dev));
 677         if (!error) {
 678                 error = smb_instantiate(dentry, 0, 0);
 679         }
 680         return error;
 681 }
 682
 683 /*
 684  * dentry = existing file
 685  * new_dentry = new file
 686  */
 687 static int
 688 smb_link(struct dentry *dentry, struct inode *dir, struct dentry *new_dentry)
 689 {
 690         int error;
 691
 692         DEBUG1("smb_link old=%s/%s new=%s/%s\n",
 693                DENTRY_PATH(dentry), DENTRY_PATH(new_dentry));
 694         smb_invalid_dir_cache(dir);
 695         error = smb_proc_link(server_from_dentry(dentry), dentry, new_dentry);
 696         if (!error) {
 697                 smb_renew_times(dentry);
 698                 error = smb_instantiate(new_dentry, 0, 0);
 699         }
 700         return error;
 701 }