fs/afs/dir.c

   1 /* dir.c: AFS filesystem directory handling
   2  *
   3  * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/fs.h>
  16 #include <linux/pagemap.h>
  17 #include <linux/ctype.h>
  18 #include <linux/sched.h>
  19 #include "internal.h"
  20
  21 static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
  22                                  struct nameidata *nd);
  23 static int afs_dir_open(struct inode *inode, struct file *file);
  24 static int afs_readdir(struct file *file, void *dirent, filldir_t filldir);
  25 static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd);
  26 static int afs_d_delete(struct dentry *dentry);
  27 static void afs_d_release(struct dentry *dentry);
  28 static int afs_lookup_filldir(void *_cookie, const char *name, int nlen,
  29                                   loff_t fpos, u64 ino, unsigned dtype);
  30 static int afs_create(struct inode *dir, struct dentry *dentry, int mode,
  31                       struct nameidata *nd);
  32 static int afs_mkdir(struct inode *dir, struct dentry *dentry, int mode);
  33 static int afs_rmdir(struct inode *dir, struct dentry *dentry);
  34 static int afs_unlink(struct inode *dir, struct dentry *dentry);
  35 static int afs_link(struct dentry *from, struct inode *dir,
  36                     struct dentry *dentry);
  37 static int afs_symlink(struct inode *dir, struct dentry *dentry,
  38                        const char *content);
  39 static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
  40                       struct inode *new_dir, struct dentry *new_dentry);
  41
  42 const struct file_operations afs_dir_file_operations = {
  43         .open           = afs_dir_open,
  44         .release        = afs_release,
  45         .readdir        = afs_readdir,
  46         .lock           = afs_lock,
  47         .llseek         = generic_file_llseek,
  48 };
  49
  50 const struct inode_operations afs_dir_inode_operations = {
  51         .create         = afs_create,
  52         .lookup         = afs_lookup,
  53         .link           = afs_link,
  54         .unlink         = afs_unlink,
  55         .symlink        = afs_symlink,
  56         .mkdir          = afs_mkdir,
  57         .rmdir          = afs_rmdir,
  58         .rename         = afs_rename,
  59         .permission     = afs_permission,
  60         .getattr        = afs_getattr,
  61         .setattr        = afs_setattr,
  62 };
  63
  64 static const struct dentry_operations afs_fs_dentry_operations = {
  65         .d_revalidate   = afs_d_revalidate,
  66         .d_delete       = afs_d_delete,
  67         .d_release      = afs_d_release,
  68 };
  69
  70 #define AFS_DIR_HASHTBL_SIZE    128
  71 #define AFS_DIR_DIRENT_SIZE     32
  72 #define AFS_DIRENT_PER_BLOCK    64
  73
  74 union afs_dirent {
  75         struct {
  76                 uint8_t         valid;
  77                 uint8_t         unused[1];
  78                 __be16          hash_next;
  79                 __be32          vnode;
  80                 __be32          unique;
  81                 uint8_t         name[16];
  82                 uint8_t         overflow[4];    /* if any char of the name (inc
  83                                                  * NUL) reaches here, consume
  84                                                  * the next dirent too */
  85         } u;
  86         uint8_t extended_name[32];
  87 };
  88
  89 /* AFS directory page header (one at the beginning of every 2048-byte chunk) */
  90 struct afs_dir_pagehdr {
  91         __be16          npages;
  92         __be16          magic;
  93 #define AFS_DIR_MAGIC htons(1234)
  94         uint8_t         nentries;
  95         uint8_t         bitmap[8];
  96         uint8_t         pad[19];
  97 };
  98
  99 /* directory block layout */
 100 union afs_dir_block {
 101
 102         struct afs_dir_pagehdr pagehdr;
 103
 104         struct {
 105                 struct afs_dir_pagehdr  pagehdr;
 106                 uint8_t                 alloc_ctrs[128];
 107                 /* dir hash table */
 108                 uint16_t                hashtable[AFS_DIR_HASHTBL_SIZE];
 109         } hdr;
 110
 111         union afs_dirent dirents[AFS_DIRENT_PER_BLOCK];
 112 };
 113
 114 /* layout on a linux VM page */
 115 struct afs_dir_page {
 116         union afs_dir_block blocks[PAGE_SIZE / sizeof(union afs_dir_block)];
 117 };
 118
 119 struct afs_lookup_cookie {
 120         struct afs_fid  fid;
 121         const char      *name;
 122         size_t          nlen;
 123         int             found;
 124 };
 125
 126 /*
 127  * check that a directory page is valid
 128  */
 129 static inline void afs_dir_check_page(struct inode *dir, struct page *page)
 130 {
 131         struct afs_dir_page *dbuf;
 132         loff_t latter;
 133         int tmp, qty;
 134
 135 #if 0
 136         /* check the page count */
 137         qty = desc.size / sizeof(dbuf->blocks[0]);
 138         if (qty == 0)
 139                 goto error;
 140
 141         if (page->index == 0 && qty != ntohs(dbuf->blocks[0].pagehdr.npages)) {
 142                 printk("kAFS: %s(%lu): wrong number of dir blocks %d!=%hu\n",
 143                        __func__, dir->i_ino, qty,
 144                        ntohs(dbuf->blocks[0].pagehdr.npages));
 145                 goto error;
 146         }
 147 #endif
 148
 149         /* determine how many magic numbers there should be in this page */
 150         latter = dir->i_size - page_offset(page);
 151         if (latter >= PAGE_SIZE)
 152                 qty = PAGE_SIZE;
 153         else
 154                 qty = latter;
 155         qty /= sizeof(union afs_dir_block);
 156
 157         /* check them */
 158         dbuf = page_address(page);
 159         for (tmp = 0; tmp < qty; tmp++) {
 160                 if (dbuf->blocks[tmp].pagehdr.magic != AFS_DIR_MAGIC) {
 161                         printk("kAFS: %s(%lu): bad magic %d/%d is %04hx\n",
 162                                __func__, dir->i_ino, tmp, qty,
 163                                ntohs(dbuf->blocks[tmp].pagehdr.magic));
 164                         goto error;
 165                 }
 166         }
 167
 168         SetPageChecked(page);
 169         return;
 170
 171 error:
 172         SetPageChecked(page);
 173         SetPageError(page);
 174 }
 175
 176 /*
 177  * discard a page cached in the pagecache
 178  */
 179 static inline void afs_dir_put_page(struct page *page)
 180 {
 181         kunmap(page);
 182         page_cache_release(page);
 183 }
 184
 185 /*
 186  * get a page into the pagecache
 187  */
 188 static struct page *afs_dir_get_page(struct inode *dir, unsigned long index,
 189                                      struct key *key)
 190 {
 191         struct page *page;
 192         _enter("{%lu},%lu", dir->i_ino, index);
 193
 194         page = read_cache_page(dir->i_mapping, index, afs_page_filler, key);
 195         if (!IS_ERR(page)) {
 196                 kmap(page);
 197                 if (!PageChecked(page))
 198                         afs_dir_check_page(dir, page);
 199                 if (PageError(page))
 200                         goto fail;
 201         }
 202         return page;
 203
 204 fail:
 205         afs_dir_put_page(page);
 206         _leave(" = -EIO");
 207         return ERR_PTR(-EIO);
 208 }
 209
 210 /*
 211  * open an AFS directory file
 212  */
 213 static int afs_dir_open(struct inode *inode, struct file *file)
 214 {
 215         _enter("{%lu}", inode->i_ino);
 216
 217         BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048);
 218         BUILD_BUG_ON(sizeof(union afs_dirent) != 32);
 219
 220         if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(inode)->flags))
 221                 return -ENOENT;
 222
 223         return afs_open(inode, file);
 224 }
 225
 226 /*
 227  * deal with one block in an AFS directory
 228  */
 229 static int afs_dir_iterate_block(unsigned *fpos,
 230                                  union afs_dir_block *block,
 231                                  unsigned blkoff,
 232                                  void *cookie,
 233                                  filldir_t filldir)
 234 {
 235         union afs_dirent *dire;
 236         unsigned offset, next, curr;
 237         size_t nlen;
 238         int tmp, ret;
 239
 240         _enter("%u,%x,%p,,",*fpos,blkoff,block);
 241
 242         curr = (*fpos - blkoff) / sizeof(union afs_dirent);
 243
 244         /* walk through the block, an entry at a time */
 245         for (offset = AFS_DIRENT_PER_BLOCK - block->pagehdr.nentries;
 246              offset < AFS_DIRENT_PER_BLOCK;
 247              offset = next
 248              ) {
 249                 next = offset + 1;
 250
 251                 /* skip entries marked unused in the bitmap */
 252                 if (!(block->pagehdr.bitmap[offset / 8] &
 253                       (1 << (offset % 8)))) {
 254                         _debug("ENT[%Zu.%u]: unused",
 255                                blkoff / sizeof(union afs_dir_block), offset);
 256                         if (offset >= curr)
 257                                 *fpos = blkoff +
 258                                         next * sizeof(union afs_dirent);
 259                         continue;
 260                 }
 261
 262                 /* got a valid entry */
 263                 dire = &block->dirents[offset];
 264                 nlen = strnlen(dire->u.name,
 265                                sizeof(*block) -
 266                                offset * sizeof(union afs_dirent));
 267
 268                 _debug("ENT[%Zu.%u]: %s %Zu \"%s\"",
 269                        blkoff / sizeof(union afs_dir_block), offset,
 270                        (offset < curr ? "skip" : "fill"),
 271                        nlen, dire->u.name);
 272
 273                 /* work out where the next possible entry is */
 274                 for (tmp = nlen; tmp > 15; tmp -= sizeof(union afs_dirent)) {
 275                         if (next >= AFS_DIRENT_PER_BLOCK) {
 276                                 _debug("ENT[%Zu.%u]:"
 277                                        " %u travelled beyond end dir block"
 278                                        " (len %u/%Zu)",
 279                                        blkoff / sizeof(union afs_dir_block),
 280                                        offset, next, tmp, nlen);
 281                                 return -EIO;
 282                         }
 283                         if (!(block->pagehdr.bitmap[next / 8] &
 284                               (1 << (next % 8)))) {
 285                                 _debug("ENT[%Zu.%u]:"
 286                                        " %u unmarked extension (len %u/%Zu)",
 287                                        blkoff / sizeof(union afs_dir_block),
 288                                        offset, next, tmp, nlen);
 289                                 return -EIO;
 290                         }
 291
 292                         _debug("ENT[%Zu.%u]: ext %u/%Zu",
 293                                blkoff / sizeof(union afs_dir_block),
 294                                next, tmp, nlen);
 295                         next++;
 296                 }
 297
 298                 /* skip if starts before the current position */
 299                 if (offset < curr)
 300                         continue;
 301
 302                 /* found the next entry */
 303                 ret = filldir(cookie,
 304                               dire->u.name,
 305                               nlen,
 306                               blkoff + offset * sizeof(union afs_dirent),
 307                               ntohl(dire->u.vnode),
 308                               filldir == afs_lookup_filldir ?
 309                               ntohl(dire->u.unique) : DT_UNKNOWN);
 310                 if (ret < 0) {
 311                         _leave(" = 0 [full]");
 312                         return 0;
 313                 }
 314
 315                 *fpos = blkoff + next * sizeof(union afs_dirent);
 316         }
 317
 318         _leave(" = 1 [more]");
 319         return 1;
 320 }
 321
 322 /*
 323  * iterate through the data blob that lists the contents of an AFS directory
 324  */
 325 static int afs_dir_iterate(struct inode *dir, unsigned *fpos, void *cookie,
 326                            filldir_t filldir, struct key *key)
 327 {
 328         union afs_dir_block *dblock;
 329         struct afs_dir_page *dbuf;
 330         struct page *page;
 331         unsigned blkoff, limit;
 332         int ret;
 333
 334         _enter("{%lu},%u,,", dir->i_ino, *fpos);
 335
 336         if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(dir)->flags)) {
 337                 _leave(" = -ESTALE");
 338                 return -ESTALE;
 339         }
 340
 341         /* round the file position up to the next entry boundary */
 342         *fpos += sizeof(union afs_dirent) - 1;
 343         *fpos &= ~(sizeof(union afs_dirent) - 1);
 344
 345         /* walk through the blocks in sequence */
 346         ret = 0;
 347         while (*fpos < dir->i_size) {
 348                 blkoff = *fpos & ~(sizeof(union afs_dir_block) - 1);
 349
 350                 /* fetch the appropriate page from the directory */
 351                 page = afs_dir_get_page(dir, blkoff / PAGE_SIZE, key);
 352                 if (IS_ERR(page)) {
 353                         ret = PTR_ERR(page);
 354                         break;
 355                 }
 356
 357                 limit = blkoff & ~(PAGE_SIZE - 1);
 358
 359                 dbuf = page_address(page);
 360
 361                 /* deal with the individual blocks stashed on this page */
 362                 do {
 363                         dblock = &dbuf->blocks[(blkoff % PAGE_SIZE) /
 364                                                sizeof(union afs_dir_block)];
 365                         ret = afs_dir_iterate_block(fpos, dblock, blkoff,
 366                                                     cookie, filldir);
 367                         if (ret != 1) {
 368                                 afs_dir_put_page(page);
 369                                 goto out;
 370                         }
 371
 372                         blkoff += sizeof(union afs_dir_block);
 373
 374                 } while (*fpos < dir->i_size && blkoff < limit);
 375
 376                 afs_dir_put_page(page);
 377                 ret = 0;
 378         }
 379
 380 out:
 381         _leave(" = %d", ret);
 382         return ret;
 383 }
 384
 385 /*
 386  * read an AFS directory
 387  */
 388 static int afs_readdir(struct file *file, void *cookie, filldir_t filldir)
 389 {
 390         unsigned fpos;
 391         int ret;
 392
 393         _enter("{%Ld,{%lu}}",
 394                file->f_pos, file->f_path.dentry->d_inode->i_ino);
 395
 396         ASSERT(file->private_data != NULL);
 397
 398         fpos = file->f_pos;
 399         ret = afs_dir_iterate(file->f_path.dentry->d_inode, &fpos,
 400                               cookie, filldir, file->private_data);
 401         file->f_pos = fpos;
 402
 403         _leave(" = %d", ret);
 404         return ret;
 405 }
 406
 407 /*
 408  * search the directory for a name
 409  * - if afs_dir_iterate_block() spots this function, it'll pass the FID
 410  *   uniquifier through dtype
 411  */
 412 static int afs_lookup_filldir(void *_cookie, const char *name, int nlen,
 413                               loff_t fpos, u64 ino, unsigned dtype)
 414 {
 415         struct afs_lookup_cookie *cookie = _cookie;
 416
 417         _enter("{%s,%Zu},%s,%u,,%llu,%u",
 418                cookie->name, cookie->nlen, name, nlen,
 419                (unsigned long long) ino, dtype);
 420
 421         /* insanity checks first */
 422         BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048);
 423         BUILD_BUG_ON(sizeof(union afs_dirent) != 32);
 424
 425         if (cookie->nlen != nlen || memcmp(cookie->name, name, nlen) != 0) {
 426                 _leave(" = 0 [no]");
 427                 return 0;
 428         }
 429
 430         cookie->fid.vnode = ino;
 431         cookie->fid.unique = dtype;
 432         cookie->found = 1;
 433
 434         _leave(" = -1 [found]");
 435         return -1;
 436 }
 437
 438 /*
 439  * do a lookup in a directory
 440  * - just returns the FID the dentry name maps to if found
 441  */
 442 static int afs_do_lookup(struct inode *dir, struct dentry *dentry,
 443                          struct afs_fid *fid, struct key *key)
 444 {
 445         struct afs_lookup_cookie cookie;
 446         struct afs_super_info *as;
 447         unsigned fpos;
 448         int ret;
 449
 450         _enter("{%lu},%p{%s},", dir->i_ino, dentry, dentry->d_name.name);
 451
 452         as = dir->i_sb->s_fs_info;
 453
 454         /* search the directory */
 455         cookie.name     = dentry->d_name.name;
 456         cookie.nlen     = dentry->d_name.len;
 457         cookie.fid.vid  = as->volume->vid;
 458         cookie.found    = 0;
 459
 460         fpos = 0;
 461         ret = afs_dir_iterate(dir, &fpos, &cookie, afs_lookup_filldir,
 462                               key);
 463         if (ret < 0) {
 464                 _leave(" = %d [iter]", ret);
 465                 return ret;
 466         }
 467
 468         ret = -ENOENT;
 469         if (!cookie.found) {
 470                 _leave(" = -ENOENT [not found]");
 471                 return -ENOENT;
 472         }
 473
 474         *fid = cookie.fid;
 475         _leave(" = 0 { vn=%u u=%u }", fid->vnode, fid->unique);
 476         return 0;
 477 }
 478
 479 /*
 480  * Try to auto mount the mountpoint with pseudo directory, if the autocell
 481  * operation is setted.
 482  */
 483 static struct inode *afs_try_auto_mntpt(
 484         int ret, struct dentry *dentry, struct inode *dir, struct key *key,
 485         struct afs_fid *fid)
 486 {
 487         const char *devname = dentry->d_name.name;
 488         struct afs_vnode *vnode = AFS_FS_I(dir);
 489         struct inode *inode;
 490
 491         _enter("%d, %p{%s}, {%x:%u}, %p",
 492                ret, dentry, devname, vnode->fid.vid, vnode->fid.vnode, key);
 493
 494         if (ret != -ENOENT ||
 495             !test_bit(AFS_VNODE_AUTOCELL, &vnode->flags))
 496                 goto out;
 497
 498         inode = afs_iget_autocell(dir, devname, strlen(devname), key);
 499         if (IS_ERR(inode)) {
 500                 ret = PTR_ERR(inode);
 501                 goto out;
 502         }
 503
 504         *fid = AFS_FS_I(inode)->fid;
 505         _leave("= %p", inode);
 506         return inode;
 507
 508 out:
 509         _leave("= %d", ret);
 510         return ERR_PTR(ret);
 511 }
 512
 513 /*
 514  * look up an entry in a directory
 515  */
 516 static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
 517                                  struct nameidata *nd)
 518 {
 519         struct afs_vnode *vnode;
 520         struct afs_fid fid;
 521         struct inode *inode;
 522         struct key *key;
 523         int ret;
 524
 525         vnode = AFS_FS_I(dir);
 526
 527         _enter("{%x:%u},%p{%s},",
 528                vnode->fid.vid, vnode->fid.vnode, dentry, dentry->d_name.name);
 529
 530         ASSERTCMP(dentry->d_inode, ==, NULL);
 531
 532         if (dentry->d_name.len >= AFSNAMEMAX) {
 533                 _leave(" = -ENAMETOOLONG");
 534                 return ERR_PTR(-ENAMETOOLONG);
 535         }
 536
 537         if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
 538                 _leave(" = -ESTALE");
 539                 return ERR_PTR(-ESTALE);
 540         }
 541
 542         key = afs_request_key(vnode->volume->cell);
 543         if (IS_ERR(key)) {
 544                 _leave(" = %ld [key]", PTR_ERR(key));
 545                 return ERR_CAST(key);
 546         }
 547
 548         ret = afs_validate(vnode, key);
 549         if (ret < 0) {
 550                 key_put(key);
 551                 _leave(" = %d [val]", ret);
 552                 return ERR_PTR(ret);
 553         }
 554
 555         ret = afs_do_lookup(dir, dentry, &fid, key);
 556         if (ret < 0) {
 557                 inode = afs_try_auto_mntpt(ret, dentry, dir, key, &fid);
 558                 if (!IS_ERR(inode)) {
 559                         key_put(key);
 560                         goto success;
 561                 }
 562
 563                 ret = PTR_ERR(inode);
 564                 key_put(key);
 565                 if (ret == -ENOENT) {
 566                         d_add(dentry, NULL);
 567                         _leave(" = NULL [negative]");
 568                         return NULL;
 569                 }
 570                 _leave(" = %d [do]", ret);
 571                 return ERR_PTR(ret);
 572         }
 573         dentry->d_fsdata = (void *)(unsigned long) vnode->status.data_version;
 574
 575         /* instantiate the dentry */
 576         inode = afs_iget(dir->i_sb, key, &fid, NULL, NULL);
 577         key_put(key);
 578         if (IS_ERR(inode)) {
 579                 _leave(" = %ld", PTR_ERR(inode));
 580                 return ERR_CAST(inode);
 581         }
 582
 583 success:
 584         dentry->d_op = &afs_fs_dentry_operations;
 585
 586         d_add(dentry, inode);
 587         _leave(" = 0 { vn=%u u=%u } -> { ino=%lu v=%llu }",
 588                fid.vnode,
 589                fid.unique,
 590                dentry->d_inode->i_ino,
 591                (unsigned long long)dentry->d_inode->i_version);
 592
 593         return NULL;
 594 }
 595
 596 /*
 597  * check that a dentry lookup hit has found a valid entry
 598  * - NOTE! the hit can be a negative hit too, so we can't assume we have an
 599  *   inode
 600  */
 601 static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
 602 {
 603         struct afs_vnode *vnode, *dir;
 604         struct afs_fid uninitialized_var(fid);
 605         struct dentry *parent;
 606         struct key *key;
 607         void *dir_version;
 608         int ret;
 609
 610         vnode = AFS_FS_I(dentry->d_inode);
 611
 612         if (dentry->d_inode)
 613                 _enter("{v={%x:%u} n=%s fl=%lx},",
 614                        vnode->fid.vid, vnode->fid.vnode, dentry->d_name.name,
 615                        vnode->flags);
 616         else
 617                 _enter("{neg n=%s}", dentry->d_name.name);
 618
 619         key = afs_request_key(AFS_FS_S(dentry->d_sb)->volume->cell);
 620         if (IS_ERR(key))
 621                 key = NULL;
 622
 623         /* lock down the parent dentry so we can peer at it */
 624         parent = dget_parent(dentry);
 625         if (!parent->d_inode)
 626                 goto out_bad;
 627
 628         dir = AFS_FS_I(parent->d_inode);
 629
 630         /* validate the parent directory */
 631         if (test_bit(AFS_VNODE_MODIFIED, &dir->flags))
 632                 afs_validate(dir, key);
 633
 634         if (test_bit(AFS_VNODE_DELETED, &dir->flags)) {
 635                 _debug("%s: parent dir deleted", dentry->d_name.name);
 636                 goto out_bad;
 637         }
 638
 639         dir_version = (void *) (unsigned long) dir->status.data_version;
 640         if (dentry->d_fsdata == dir_version)
 641                 goto out_valid; /* the dir contents are unchanged */
 642
 643         _debug("dir modified");
 644
 645         /* search the directory for this vnode */
 646         ret = afs_do_lookup(&dir->vfs_inode, dentry, &fid, key);
 647         switch (ret) {
 648         case 0:
 649                 /* the filename maps to something */
 650                 if (!dentry->d_inode)
 651                         goto out_bad;
 652                 if (is_bad_inode(dentry->d_inode)) {
 653                         printk("kAFS: afs_d_revalidate: %s/%s has bad inode\n",
 654                                parent->d_name.name, dentry->d_name.name);
 655                         goto out_bad;
 656                 }
 657
 658                 /* if the vnode ID has changed, then the dirent points to a
 659                  * different file */
 660                 if (fid.vnode != vnode->fid.vnode) {
 661                         _debug("%s: dirent changed [%u != %u]",
 662                                dentry->d_name.name, fid.vnode,
 663                                vnode->fid.vnode);
 664                         goto not_found;
 665                 }
 666
 667                 /* if the vnode ID uniqifier has changed, then the file has
 668                  * been deleted and replaced, and the original vnode ID has
 669                  * been reused */
 670                 if (fid.unique != vnode->fid.unique) {
 671                         _debug("%s: file deleted (uq %u -> %u I:%llu)",
 672                                dentry->d_name.name, fid.unique,
 673                                vnode->fid.unique,
 674                                (unsigned long long)dentry->d_inode->i_version);
 675                         spin_lock(&vnode->lock);
 676                         set_bit(AFS_VNODE_DELETED, &vnode->flags);
 677                         spin_unlock(&vnode->lock);
 678                         goto not_found;
 679                 }
 680                 goto out_valid;
 681
 682         case -ENOENT:
 683                 /* the filename is unknown */
 684                 _debug("%s: dirent not found", dentry->d_name.name);
 685                 if (dentry->d_inode)
 686                         goto not_found;
 687                 goto out_valid;
 688
 689         default:
 690                 _debug("failed to iterate dir %s: %d",
 691                        parent->d_name.name, ret);
 692                 goto out_bad;
 693         }
 694
 695 out_valid:
 696         dentry->d_fsdata = dir_version;
 697 out_skip:
 698         dput(parent);
 699         key_put(key);
 700         _leave(" = 1 [valid]");
 701         return 1;
 702
 703         /* the dirent, if it exists, now points to a different vnode */
 704 not_found:
 705         spin_lock(&dentry->d_lock);
 706         dentry->d_flags |= DCACHE_NFSFS_RENAMED;
 707         spin_unlock(&dentry->d_lock);
 708
 709 out_bad:
 710         if (dentry->d_inode) {
 711                 /* don't unhash if we have submounts */
 712                 if (have_submounts(dentry))
 713                         goto out_skip;
 714         }
 715
 716         _debug("dropping dentry %s/%s",
 717                parent->d_name.name, dentry->d_name.name);
 718         shrink_dcache_parent(dentry);
 719         d_drop(dentry);
 720         dput(parent);
 721         key_put(key);
 722
 723         _leave(" = 0 [bad]");
 724         return 0;
 725 }
 726
 727 /*
 728  * allow the VFS to enquire as to whether a dentry should be unhashed (mustn't
 729  * sleep)
 730  * - called from dput() when d_count is going to 0.
 731  * - return 1 to request dentry be unhashed, 0 otherwise
 732  */
 733 static int afs_d_delete(struct dentry *dentry)
 734 {
 735         _enter("%s", dentry->d_name.name);
 736
 737         if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
 738                 goto zap;
 739
 740         if (dentry->d_inode &&
 741             (test_bit(AFS_VNODE_DELETED,   &AFS_FS_I(dentry->d_inode)->flags) ||
 742              test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(dentry->d_inode)->flags)))
 743                 goto zap;
 744
 745         _leave(" = 0 [keep]");
 746         return 0;
 747
 748 zap:
 749         _leave(" = 1 [zap]");
 750         return 1;
 751 }
 752
 753 /*
 754  * handle dentry release
 755  */
 756 static void afs_d_release(struct dentry *dentry)
 757 {
 758         _enter("%s", dentry->d_name.name);
 759 }
 760
 761 /*
 762  * create a directory on an AFS filesystem
 763  */
 764 static int afs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 765 {
 766         struct afs_file_status status;
 767         struct afs_callback cb;
 768         struct afs_server *server;
 769         struct afs_vnode *dvnode, *vnode;
 770         struct afs_fid fid;
 771         struct inode *inode;
 772         struct key *key;
 773         int ret;
 774
 775         dvnode = AFS_FS_I(dir);
 776
 777         _enter("{%x:%u},{%s},%o",
 778                dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name, mode);
 779
 780         ret = -ENAMETOOLONG;
 781         if (dentry->d_name.len >= AFSNAMEMAX)
 782                 goto error;
 783
 784         key = afs_request_key(dvnode->volume->cell);
 785         if (IS_ERR(key)) {
 786                 ret = PTR_ERR(key);
 787                 goto error;
 788         }
 789
 790         mode |= S_IFDIR;
 791         ret = afs_vnode_create(dvnode, key, dentry->d_name.name,
 792                                mode, &fid, &status, &cb, &server);
 793         if (ret < 0)
 794                 goto mkdir_error;
 795
 796         inode = afs_iget(dir->i_sb, key, &fid, &status, &cb);
 797         if (IS_ERR(inode)) {
 798                 /* ENOMEM at a really inconvenient time - just abandon the new
 799                  * directory on the server */
 800                 ret = PTR_ERR(inode);
 801                 goto iget_error;
 802         }
 803
 804         /* apply the status report we've got for the new vnode */
 805         vnode = AFS_FS_I(inode);
 806         spin_lock(&vnode->lock);
 807         vnode->update_cnt++;
 808         spin_unlock(&vnode->lock);
 809         afs_vnode_finalise_status_update(vnode, server);
 810         afs_put_server(server);
 811
 812         d_instantiate(dentry, inode);
 813         if (d_unhashed(dentry)) {
 814                 _debug("not hashed");
 815                 d_rehash(dentry);
 816         }
 817         key_put(key);
 818         _leave(" = 0");
 819         return 0;
 820
 821 iget_error:
 822         afs_put_server(server);
 823 mkdir_error:
 824         key_put(key);
 825 error:
 826         d_drop(dentry);
 827         _leave(" = %d", ret);
 828         return ret;
 829 }
 830
 831 /*
 832  * remove a directory from an AFS filesystem
 833  */
 834 static int afs_rmdir(struct inode *dir, struct dentry *dentry)
 835 {
 836         struct afs_vnode *dvnode, *vnode;
 837         struct key *key;
 838         int ret;
 839
 840         dvnode = AFS_FS_I(dir);
 841
 842         _enter("{%x:%u},{%s}",
 843                dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name);
 844
 845         ret = -ENAMETOOLONG;
 846         if (dentry->d_name.len >= AFSNAMEMAX)
 847                 goto error;
 848
 849         key = afs_request_key(dvnode->volume->cell);
 850         if (IS_ERR(key)) {
 851                 ret = PTR_ERR(key);
 852                 goto error;
 853         }
 854
 855         ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, true);
 856         if (ret < 0)
 857                 goto rmdir_error;
 858
 859         if (dentry->d_inode) {
 860                 vnode = AFS_FS_I(dentry->d_inode);
 861                 clear_nlink(&vnode->vfs_inode);
 862                 set_bit(AFS_VNODE_DELETED, &vnode->flags);
 863                 afs_discard_callback_on_delete(vnode);
 864         }
 865
 866         key_put(key);
 867         _leave(" = 0");
 868         return 0;
 869
 870 rmdir_error:
 871         key_put(key);
 872 error:
 873         _leave(" = %d", ret);
 874         return ret;
 875 }
 876
 877 /*
 878  * remove a file from an AFS filesystem
 879  */
 880 static int afs_unlink(struct inode *dir, struct dentry *dentry)
 881 {
 882         struct afs_vnode *dvnode, *vnode;
 883         struct key *key;
 884         int ret;
 885
 886         dvnode = AFS_FS_I(dir);
 887
 888         _enter("{%x:%u},{%s}",
 889                dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name);
 890
 891         ret = -ENAMETOOLONG;
 892         if (dentry->d_name.len >= AFSNAMEMAX)
 893                 goto error;
 894
 895         key = afs_request_key(dvnode->volume->cell);
 896         if (IS_ERR(key)) {
 897                 ret = PTR_ERR(key);
 898                 goto error;
 899         }
 900
 901         if (dentry->d_inode) {
 902                 vnode = AFS_FS_I(dentry->d_inode);
 903
 904                 /* make sure we have a callback promise on the victim */
 905                 ret = afs_validate(vnode, key);
 906                 if (ret < 0)
 907                         goto error;
 908         }
 909
 910         ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, false);
 911         if (ret < 0)
 912                 goto remove_error;
 913
 914         if (dentry->d_inode) {
 915                 /* if the file wasn't deleted due to excess hard links, the
 916                  * fileserver will break the callback promise on the file - if
 917                  * it had one - before it returns to us, and if it was deleted,
 918                  * it won't
 919                  *
 920                  * however, if we didn't have a callback promise outstanding,
 921                  * or it was outstanding on a different server, then it won't
 922                  * break it either...
 923                  */
 924                 vnode = AFS_FS_I(dentry->d_inode);
 925                 if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
 926                         _debug("AFS_VNODE_DELETED");
 927                 if (test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags))
 928                         _debug("AFS_VNODE_CB_BROKEN");
 929                 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
 930                 ret = afs_validate(vnode, key);
 931                 _debug("nlink %d [val %d]", vnode->vfs_inode.i_nlink, ret);
 932         }
 933
 934         key_put(key);
 935         _leave(" = 0");
 936         return 0;
 937
 938 remove_error:
 939         key_put(key);
 940 error:
 941         _leave(" = %d", ret);
 942         return ret;
 943 }
 944
 945 /*
 946  * create a regular file on an AFS filesystem
 947  */
 948 static int afs_create(struct inode *dir, struct dentry *dentry, int mode,
 949                       struct nameidata *nd)
 950 {
 951         struct afs_file_status status;
 952         struct afs_callback cb;
 953         struct afs_server *server;
 954         struct afs_vnode *dvnode, *vnode;
 955         struct afs_fid fid;
 956         struct inode *inode;
 957         struct key *key;
 958         int ret;
 959
 960         dvnode = AFS_FS_I(dir);
 961
 962         _enter("{%x:%u},{%s},%o,",
 963                dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name, mode);
 964
 965         ret = -ENAMETOOLONG;
 966         if (dentry->d_name.len >= AFSNAMEMAX)
 967                 goto error;
 968
 969         key = afs_request_key(dvnode->volume->cell);
 970         if (IS_ERR(key)) {
 971                 ret = PTR_ERR(key);
 972                 goto error;
 973         }
 974
 975         mode |= S_IFREG;
 976         ret = afs_vnode_create(dvnode, key, dentry->d_name.name,
 977                                mode, &fid, &status, &cb, &server);
 978         if (ret < 0)
 979                 goto create_error;
 980
 981         inode = afs_iget(dir->i_sb, key, &fid, &status, &cb);
 982         if (IS_ERR(inode)) {
 983                 /* ENOMEM at a really inconvenient time - just abandon the new
 984                  * directory on the server */
 985                 ret = PTR_ERR(inode);
 986                 goto iget_error;
 987         }
 988
 989         /* apply the status report we've got for the new vnode */
 990         vnode = AFS_FS_I(inode);
 991         spin_lock(&vnode->lock);
 992         vnode->update_cnt++;
 993         spin_unlock(&vnode->lock);
 994         afs_vnode_finalise_status_update(vnode, server);
 995         afs_put_server(server);
 996
 997         d_instantiate(dentry, inode);
 998         if (d_unhashed(dentry)) {
 999                 _debug("not hashed");
1000                 d_rehash(dentry);
1001         }
1002         key_put(key);
1003         _leave(" = 0");
1004         return 0;
1005
1006 iget_error:
1007         afs_put_server(server);
1008 create_error:
1009         key_put(key);
1010 error:
1011         d_drop(dentry);
1012         _leave(" = %d", ret);
1013         return ret;
1014 }
1015
1016 /*
1017  * create a hard link between files in an AFS filesystem
1018  */
1019 static int afs_link(struct dentry *from, struct inode *dir,
1020                     struct dentry *dentry)
1021 {
1022         struct afs_vnode *dvnode, *vnode;
1023         struct key *key;
1024         int ret;
1025
1026         vnode = AFS_FS_I(from->d_inode);
1027         dvnode = AFS_FS_I(dir);
1028
1029         _enter("{%x:%u},{%x:%u},{%s}",
1030                vnode->fid.vid, vnode->fid.vnode,
1031                dvnode->fid.vid, dvnode->fid.vnode,
1032                dentry->d_name.name);
1033
1034         ret = -ENAMETOOLONG;
1035         if (dentry->d_name.len >= AFSNAMEMAX)
1036                 goto error;
1037
1038         key = afs_request_key(dvnode->volume->cell);
1039         if (IS_ERR(key)) {
1040                 ret = PTR_ERR(key);
1041                 goto error;
1042         }
1043
1044         ret = afs_vnode_link(dvnode, vnode, key, dentry->d_name.name);
1045         if (ret < 0)
1046                 goto link_error;
1047
1048         atomic_inc(&vnode->vfs_inode.i_count);
1049         d_instantiate(dentry, &vnode->vfs_inode);
1050         key_put(key);
1051         _leave(" = 0");
1052         return 0;
1053
1054 link_error:
1055         key_put(key);
1056 error:
1057         d_drop(dentry);
1058         _leave(" = %d", ret);
1059         return ret;
1060 }
1061
1062 /*
1063  * create a symlink in an AFS filesystem
1064  */
1065 static int afs_symlink(struct inode *dir, struct dentry *dentry,
1066                        const char *content)
1067 {
1068         struct afs_file_status status;
1069         struct afs_server *server;
1070         struct afs_vnode *dvnode, *vnode;
1071         struct afs_fid fid;
1072         struct inode *inode;
1073         struct key *key;
1074         int ret;
1075
1076         dvnode = AFS_FS_I(dir);
1077
1078         _enter("{%x:%u},{%s},%s",
1079                dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name,
1080                content);
1081
1082         ret = -ENAMETOOLONG;
1083         if (dentry->d_name.len >= AFSNAMEMAX)
1084                 goto error;
1085
1086         ret = -EINVAL;
1087         if (strlen(content) >= AFSPATHMAX)
1088                 goto error;
1089
1090         key = afs_request_key(dvnode->volume->cell);
1091         if (IS_ERR(key)) {
1092                 ret = PTR_ERR(key);
1093                 goto error;
1094         }
1095
1096         ret = afs_vnode_symlink(dvnode, key, dentry->d_name.name, content,
1097                                 &fid, &status, &server);
1098         if (ret < 0)
1099                 goto create_error;
1100
1101         inode = afs_iget(dir->i_sb, key, &fid, &status, NULL);
1102         if (IS_ERR(inode)) {
1103                 /* ENOMEM at a really inconvenient time - just abandon the new
1104                  * directory on the server */
1105                 ret = PTR_ERR(inode);
1106                 goto iget_error;
1107         }
1108
1109         /* apply the status report we've got for the new vnode */
1110         vnode = AFS_FS_I(inode);
1111         spin_lock(&vnode->lock);
1112         vnode->update_cnt++;
1113         spin_unlock(&vnode->lock);
1114         afs_vnode_finalise_status_update(vnode, server);
1115         afs_put_server(server);
1116
1117         d_instantiate(dentry, inode);
1118         if (d_unhashed(dentry)) {
1119                 _debug("not hashed");
1120                 d_rehash(dentry);
1121         }
1122         key_put(key);
1123         _leave(" = 0");
1124         return 0;
1125
1126 iget_error:
1127         afs_put_server(server);
1128 create_error:
1129         key_put(key);
1130 error:
1131         d_drop(dentry);
1132         _leave(" = %d", ret);
1133         return ret;
1134 }
1135
1136 /*
1137  * rename a file in an AFS filesystem and/or move it between directories
1138  */
1139 static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
1140                       struct inode *new_dir, struct dentry *new_dentry)
1141 {
1142         struct afs_vnode *orig_dvnode, *new_dvnode, *vnode;
1143         struct key *key;
1144         int ret;
1145
1146         vnode = AFS_FS_I(old_dentry->d_inode);
1147         orig_dvnode = AFS_FS_I(old_dir);
1148         new_dvnode = AFS_FS_I(new_dir);
1149
1150         _enter("{%x:%u},{%x:%u},{%x:%u},{%s}",
1151                orig_dvnode->fid.vid, orig_dvnode->fid.vnode,
1152                vnode->fid.vid, vnode->fid.vnode,
1153                new_dvnode->fid.vid, new_dvnode->fid.vnode,
1154                new_dentry->d_name.name);
1155
1156         ret = -ENAMETOOLONG;
1157         if (new_dentry->d_name.len >= AFSNAMEMAX)
1158                 goto error;
1159
1160         key = afs_request_key(orig_dvnode->volume->cell);
1161         if (IS_ERR(key)) {
1162                 ret = PTR_ERR(key);
1163                 goto error;
1164         }
1165
1166         ret = afs_vnode_rename(orig_dvnode, new_dvnode, key,
1167                                old_dentry->d_name.name,
1168                                new_dentry->d_name.name);
1169         if (ret < 0)
1170                 goto rename_error;
1171         key_put(key);
1172         _leave(" = 0");
1173         return 0;
1174
1175 rename_error:
1176         key_put(key);
1177 error:
1178         d_drop(new_dentry);
1179         _leave(" = %d", ret);
1180         return ret;
1181 }