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