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