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/namei.h>
  17 #include <linux/pagemap.h>
  18 #include <linux/ctype.h>
  19 #include <linux/sched.h>
  20 #include "internal.h"
  21
  22 static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
  23                                  struct nameidata *nd);
  24 static int afs_dir_open(struct inode *inode, struct file *file);
  25 static int afs_readdir(struct file *file, void *dirent, filldir_t filldir);
  26 static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd);
  27 static int afs_d_delete(const struct dentry *dentry);
  28 static void afs_d_release(struct dentry *dentry);
  29 static int afs_lookup_filldir(void *_cookie, const char *name, int nlen,
  30                                   loff_t fpos, u64 ino, unsigned dtype);
  31 static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
  32                       struct nameidata *nd);
  33 static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode);
  34 static int afs_rmdir(struct inode *dir, struct dentry *dentry);
  35 static int afs_unlink(struct inode *dir, struct dentry *dentry);
  36 static int afs_link(struct dentry *from, struct inode *dir,
  37                     struct dentry *dentry);
  38 static int afs_symlink(struct inode *dir, struct dentry *dentry,
  39                        const char *content);
  40 static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
  41                       struct inode *new_dir, struct dentry *new_dentry);
  42
  43 const struct file_operations afs_dir_file_operations = {
  44         .open           = afs_dir_open,
  45         .release        = afs_release,
  46         .readdir        = afs_readdir,
  47         .lock           = afs_lock,
  48         .llseek         = generic_file_llseek,
  49 };
  50
  51 const struct inode_operations afs_dir_inode_operations = {
  52         .create         = afs_create,
  53         .lookup         = afs_lookup,
  54         .link           = afs_link,
  55         .unlink         = afs_unlink,
  56         .symlink        = afs_symlink,
  57         .mkdir          = afs_mkdir,
  58         .rmdir          = afs_rmdir,
  59         .rename         = afs_rename,
  60         .permission     = afs_permission,
  61         .getattr        = afs_getattr,
  62         .setattr        = afs_setattr,
  63 };
  64
  65 const struct dentry_operations afs_fs_dentry_operations = {
  66         .d_revalidate   = afs_d_revalidate,
  67         .d_delete       = afs_d_delete,
  68         .d_release      = afs_d_release,
  69         .d_automount    = afs_d_automount,
  70 };
  71
  72 #define AFS_DIR_HASHTBL_SIZE    128
  73 #define AFS_DIR_DIRENT_SIZE     32
  74 #define AFS_DIRENT_PER_BLOCK    64
  75
  76 union afs_dirent {
  77         struct {
  78                 uint8_t         valid;
  79                 uint8_t         unused[1];
  80                 __be16          hash_next;
  81                 __be32          vnode;
  82                 __be32          unique;
  83                 uint8_t         name[16];
  84                 uint8_t         overflow[4];    /* if any char of the name (inc
  85                                                  * NUL) reaches here, consume
  86                                                  * the next dirent too */
  87         } u;
  88         uint8_t extended_name[32];
  89 };
  90
  91 /* AFS directory page header (one at the beginning of every 2048-byte chunk) */
  92 struct afs_dir_pagehdr {
  93         __be16          npages;
  94         __be16          magic;
  95 #define AFS_DIR_MAGIC htons(1234)
  96         uint8_t         nentries;
  97         uint8_t         bitmap[8];
  98         uint8_t         pad[19];
  99 };
 100
 101 /* directory block layout */
 102 union afs_dir_block {
 103
 104         struct afs_dir_pagehdr pagehdr;
 105
 106         struct {
 107                 struct afs_dir_pagehdr  pagehdr;
 108                 uint8_t                 alloc_ctrs[128];
 109                 /* dir hash table */
 110                 uint16_t                hashtable[AFS_DIR_HASHTBL_SIZE];
 111         } hdr;
 112
 113         union afs_dirent dirents[AFS_DIRENT_PER_BLOCK];
 114 };
 115
 116 /* layout on a linux VM page */
 117 struct afs_dir_page {
 118         union afs_dir_block blocks[PAGE_SIZE / sizeof(union afs_dir_block)];
 119 };
 120
 121 struct afs_lookup_cookie {
 122         struct afs_fid  fid;
 123         const char      *name;
 124         size_t          nlen;
 125         int             found;
 126 };
 127
 128 /*
 129  * check that a directory page is valid
 130  */
 131 static inline void afs_dir_check_page(struct inode *dir, struct page *page)
 132 {
 133         struct afs_dir_page *dbuf;
 134         loff_t latter;
 135         int tmp, qty;
 136
 137 #if 0
 138         /* check the page count */
 139         qty = desc.size / sizeof(dbuf->blocks[0]);
 140         if (qty == 0)
 141                 goto error;
 142
 143         if (page->index == 0 && qty != ntohs(dbuf->blocks[0].pagehdr.npages)) {
 144                 printk("kAFS: %s(%lu): wrong number of dir blocks %d!=%hu\n",
 145                        __func__, dir->i_ino, qty,
 146                        ntohs(dbuf->blocks[0].pagehdr.npages));
 147                 goto error;
 148         }
 149 #endif
 150
 151         /* determine how many magic numbers there should be in this page */
 152         latter = dir->i_size - page_offset(page);
 153         if (latter >= PAGE_SIZE)
 154                 qty = PAGE_SIZE;
 155         else
 156                 qty = latter;
 157         qty /= sizeof(union afs_dir_block);
 158
 159         /* check them */
 160         dbuf = page_address(page);
 161         for (tmp = 0; tmp < qty; tmp++) {
 162                 if (dbuf->blocks[tmp].pagehdr.magic != AFS_DIR_MAGIC) {
 163                         printk("kAFS: %s(%lu): bad magic %d/%d is %04hx\n",
 164                                __func__, dir->i_ino, tmp, qty,
 165                                ntohs(dbuf->blocks[tmp].pagehdr.magic));
 166                         goto error;
 167                 }
 168         }
 169
 170         SetPageChecked(page);
 171         return;
 172
 173 error:
 174         SetPageChecked(page);
 175         SetPageError(page);
 176 }
 177
 178 /*
 179  * discard a page cached in the pagecache
 180  */
 181 static inline void afs_dir_put_page(struct page *page)
 182 {
 183         kunmap(page);
 184         page_cache_release(page);
 185 }
 186
 187 /*
 188  * get a page into the pagecache
 189  */
 190 static struct page *afs_dir_get_page(struct inode *dir, unsigned long index,
 191                                      struct key *key)
 192 {
 193         struct page *page;
 194         _enter("{%lu},%lu", dir->i_ino, index);
 195
 196         page = read_cache_page(dir->i_mapping, index, afs_page_filler, key);
 197         if (!IS_ERR(page)) {
 198                 kmap(page);
 199                 if (!PageChecked(page))
 200                         afs_dir_check_page(dir, page);
 201                 if (PageError(page))
 202                         goto fail;
 203         }
 204         return page;
 205
 206 fail:
 207         afs_dir_put_page(page);
 208         _leave(" = -EIO");
 209         return ERR_PTR(-EIO);
 210 }
 211
 212 /*
 213  * open an AFS directory file
 214  */
 215 static int afs_dir_open(struct inode *inode, struct file *file)
 216 {
 217         _enter("{%lu}", inode->i_ino);
 218
 219         BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048);
 220         BUILD_BUG_ON(sizeof(union afs_dirent) != 32);
 221
 222         if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(inode)->flags))
 223                 return -ENOENT;
 224
 225         return afs_open(inode, file);
 226 }
 227
 228 /*
 229  * deal with one block in an AFS directory
 230  */
 231 static int afs_dir_iterate_block(unsigned *fpos,
 232                                  union afs_dir_block *block,
 233                                  unsigned blkoff,
 234                                  void *cookie,
 235                                  filldir_t filldir)
 236 {
 237         union afs_dirent *dire;
 238         unsigned offset, next, curr;
 239         size_t nlen;
 240         int tmp, ret;
 241
 242         _enter("%u,%x,%p,,",*fpos,blkoff,block);
 243
 244         curr = (*fpos - blkoff) / sizeof(union afs_dirent);
 245
 246         /* walk through the block, an entry at a time */
 247         for (offset = AFS_DIRENT_PER_BLOCK - block->pagehdr.nentries;
 248              offset < AFS_DIRENT_PER_BLOCK;
 249              offset = next
 250              ) {
 251                 next = offset + 1;
 252
 253                 /* skip entries marked unused in the bitmap */
 254                 if (!(block->pagehdr.bitmap[offset / 8] &
 255                       (1 << (offset % 8)))) {
 256                         _debug("ENT[%Zu.%u]: unused",
 257                                blkoff / sizeof(union afs_dir_block), offset);
 258                         if (offset >= curr)
 259                                 *fpos = blkoff +
 260                                         next * sizeof(union afs_dirent);
 261                         continue;
 262                 }
 263
 264                 /* got a valid entry */
 265                 dire = &block->dirents[offset];
 266                 nlen = strnlen(dire->u.name,
 267                                sizeof(*block) -
 268                                offset * sizeof(union afs_dirent));
 269
 270                 _debug("ENT[%Zu.%u]: %s %Zu \"%s\"",
 271                        blkoff / sizeof(union afs_dir_block), offset,
 272                        (offset < curr ? "skip" : "fill"),
 273                        nlen, dire->u.name);
 274
 275                 /* work out where the next possible entry is */
 276                 for (tmp = nlen; tmp > 15; tmp -= sizeof(union afs_dirent)) {
 277                         if (next >= AFS_DIRENT_PER_BLOCK) {
 278                                 _debug("ENT[%Zu.%u]:"
 279                                        " %u travelled beyond end dir block"
 280                                        " (len %u/%Zu)",
 281                                        blkoff / sizeof(union afs_dir_block),
 282                                        offset, next, tmp, nlen);
 283                                 return -EIO;
 284                         }
 285                         if (!(block->pagehdr.bitmap[next / 8] &
 286                               (1 << (next % 8)))) {
 287                                 _debug("ENT[%Zu.%u]:"
 288                                        " %u unmarked extension (len %u/%Zu)",
 289                                        blkoff / sizeof(union afs_dir_block),
 290                                        offset, next, tmp, nlen);
 291                                 return -EIO;
 292                         }
 293
 294                         _debug("ENT[%Zu.%u]: ext %u/%Zu",
 295                                blkoff / sizeof(union afs_dir_block),
 296                                next, tmp, nlen);
 297                         next++;
 298                 }
 299
 300                 /* skip if starts before the current position */
 301                 if (offset < curr)
 302                         continue;
 303
 304                 /* found the next entry */
 305                 ret = filldir(cookie,
 306                               dire->u.name,
 307                               nlen,
 308                               blkoff + offset * sizeof(union afs_dirent),
 309                               ntohl(dire->u.vnode),
 310                               filldir == afs_lookup_filldir ?
 311                               ntohl(dire->u.unique) : DT_UNKNOWN);
 312                 if (ret < 0) {
 313                         _leave(" = 0 [full]");
 314                         return 0;
 315                 }
 316
 317                 *fpos = blkoff + next * sizeof(union afs_dirent);
 318         }
 319
 320         _leave(" = 1 [more]");
 321         return 1;
 322 }
 323
 324 /*
 325  * iterate through the data blob that lists the contents of an AFS directory
 326  */
 327 static int afs_dir_iterate(struct inode *dir, unsigned *fpos, void *cookie,
 328                            filldir_t filldir, struct key *key)
 329 {
 330         union afs_dir_block *dblock;
 331         struct afs_dir_page *dbuf;
 332         struct page *page;
 333         unsigned blkoff, limit;
 334         int ret;
 335
 336         _enter("{%lu},%u,,", dir->i_ino, *fpos);
 337
 338         if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(dir)->flags)) {
 339                 _leave(" = -ESTALE");
 340                 return -ESTALE;
 341         }
 342
 343         /* round the file position up to the next entry boundary */
 344         *fpos += sizeof(union afs_dirent) - 1;
 345         *fpos &= ~(sizeof(union afs_dirent) - 1);
 346
 347         /* walk through the blocks in sequence */
 348         ret = 0;
 349         while (*fpos < dir->i_size) {
 350                 blkoff = *fpos & ~(sizeof(union afs_dir_block) - 1);
 351
 352                 /* fetch the appropriate page from the directory */
 353                 page = afs_dir_get_page(dir, blkoff / PAGE_SIZE, key);
 354                 if (IS_ERR(page)) {
 355                         ret = PTR_ERR(page);
 356                         break;
 357                 }
 358
 359                 limit = blkoff & ~(PAGE_SIZE - 1);
 360
 361                 dbuf = page_address(page);
 362
 363                 /* deal with the individual blocks stashed on this page */
 364                 do {
 365                         dblock = &dbuf->blocks[(blkoff % PAGE_SIZE) /
 366                                                sizeof(union afs_dir_block)];
 367                         ret = afs_dir_iterate_block(fpos, dblock, blkoff,
 368                                                     cookie, filldir);
 369                         if (ret != 1) {
 370                                 afs_dir_put_page(page);
 371                                 goto out;
 372                         }
 373
 374                         blkoff += sizeof(union afs_dir_block);
 375
 376                 } while (*fpos < dir->i_size && blkoff < limit);
 377
 378                 afs_dir_put_page(page);
 379                 ret = 0;
 380         }
 381
 382 out:
 383         _leave(" = %d", ret);
 384         return ret;
 385 }
 386
 387 /*
 388  * read an AFS directory
 389  */
 390 static int afs_readdir(struct file *file, void *cookie, filldir_t filldir)
 391 {
 392         unsigned fpos;
 393         int ret;
 394
 395         _enter("{%Ld,{%lu}}",
 396                file->f_pos, file->f_path.dentry->d_inode->i_ino);
 397
 398         ASSERT(file->private_data != NULL);
 399
 400         fpos = file->f_pos;
 401         ret = afs_dir_iterate(file->f_path.dentry->d_inode, &fpos,
 402                               cookie, filldir, file->private_data);
 403         file->f_pos = fpos;
 404
 405         _leave(" = %d", ret);
 406         return ret;
 407 }
 408
 409 /*
 410  * search the directory for a name
 411  * - if afs_dir_iterate_block() spots this function, it'll pass the FID
 412  *   uniquifier through dtype
 413  */
 414 static int afs_lookup_filldir(void *_cookie, const char *name, int nlen,
 415                               loff_t fpos, u64 ino, unsigned dtype)
 416 {
 417         struct afs_lookup_cookie *cookie = _cookie;
 418
 419         _enter("{%s,%Zu},%s,%u,,%llu,%u",
 420                cookie->name, cookie->nlen, name, nlen,
 421                (unsigned long long) ino, dtype);
 422
 423         /* insanity checks first */
 424         BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048);
 425         BUILD_BUG_ON(sizeof(union afs_dirent) != 32);
 426
 427         if (cookie->nlen != nlen || memcmp(cookie->name, name, nlen) != 0) {
 428                 _leave(" = 0 [no]");
 429                 return 0;
 430         }
 431
 432         cookie->fid.vnode = ino;
 433         cookie->fid.unique = dtype;
 434         cookie->found = 1;
 435
 436         _leave(" = -1 [found]");
 437         return -1;
 438 }
 439
 440 /*
 441  * do a lookup in a directory
 442  * - just returns the FID the dentry name maps to if found
 443  */
 444 static int afs_do_lookup(struct inode *dir, struct dentry *dentry,
 445                          struct afs_fid *fid, struct key *key)
 446 {
 447         struct afs_lookup_cookie cookie;
 448         struct afs_super_info *as;
 449         unsigned fpos;
 450         int ret;
 451
 452         _enter("{%lu},%p{%s},", dir->i_ino, dentry, dentry->d_name.name);
 453
 454         as = dir->i_sb->s_fs_info;
 455
 456         /* search the directory */
 457         cookie.name     = dentry->d_name.name;
 458         cookie.nlen     = dentry->d_name.len;
 459         cookie.fid.vid  = as->volume->vid;
 460         cookie.found    = 0;
 461
 462         fpos = 0;
 463         ret = afs_dir_iterate(dir, &fpos, &cookie, afs_lookup_filldir,
 464                               key);
 465         if (ret < 0) {
 466                 _leave(" = %d [iter]", ret);
 467                 return ret;
 468         }
 469
 470         ret = -ENOENT;
 471         if (!cookie.found) {
 472                 _leave(" = -ENOENT [not found]");
 473                 return -ENOENT;
 474         }
 475
 476         *fid = cookie.fid;
 477         _leave(" = 0 { vn=%u u=%u }", fid->vnode, fid->unique);
 478         return 0;
 479 }
 480
 481 /*
 482  * Try to auto mount the mountpoint with pseudo directory, if the autocell
 483  * operation is setted.
 484  */
 485 static struct inode *afs_try_auto_mntpt(
 486         int ret, struct dentry *dentry, struct inode *dir, struct key *key,
 487         struct afs_fid *fid)
 488 {
 489         const char *devname = dentry->d_name.name;
 490         struct afs_vnode *vnode = AFS_FS_I(dir);
 491         struct inode *inode;
 492
 493         _enter("%d, %p{%s}, {%x:%u}, %p",
 494                ret, dentry, devname, vnode->fid.vid, vnode->fid.vnode, key);
 495
 496         if (ret != -ENOENT ||
 497             !test_bit(AFS_VNODE_AUTOCELL, &vnode->flags))
 498                 goto out;
 499
 500         inode = afs_iget_autocell(dir, devname, strlen(devname), key);
 501         if (IS_ERR(inode)) {
 502                 ret = PTR_ERR(inode);
 503                 goto out;
 504         }
 505
 506         *fid = AFS_FS_I(inode)->fid;
 507         _leave("= %p", inode);
 508         return inode;
 509
 510 out:
 511         _leave("= %d", ret);
 512         return ERR_PTR(ret);
 513 }
 514
 515 /*
 516  * look up an entry in a directory
 517  */
 518 static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
 519                                  struct nameidata *nd)
 520 {
 521         struct afs_vnode *vnode;
 522         struct afs_fid fid;
 523         struct inode *inode;
 524         struct key *key;
 525         int ret;
 526
 527         vnode = AFS_FS_I(dir);
 528
 529         _enter("{%x:%u},%p{%s},",
 530                vnode->fid.vid, vnode->fid.vnode, dentry, dentry->d_name.name);
 531
 532         ASSERTCMP(dentry->d_inode, ==, NULL);
 533
 534         if (dentry->d_name.len >= AFSNAMEMAX) {
 535                 _leave(" = -ENAMETOOLONG");
 536                 return ERR_PTR(-ENAMETOOLONG);
 537         }
 538
 539         if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
 540                 _leave(" = -ESTALE");
 541                 return ERR_PTR(-ESTALE);
 542         }
 543
 544         key = afs_request_key(vnode->volume->cell);
 545         if (IS_ERR(key)) {
 546                 _leave(" = %ld [key]", PTR_ERR(key));
 547                 return ERR_CAST(key);
 548         }
 549
 550         ret = afs_validate(vnode, key);
 551         if (ret < 0) {
 552                 key_put(key);
 553                 _leave(" = %d [val]", ret);
 554                 return ERR_PTR(ret);
 555         }
 556
 557         ret = afs_do_lookup(dir, dentry, &fid, key);
 558         if (ret < 0) {
 559                 inode = afs_try_auto_mntpt(ret, dentry, dir, key, &fid);
 560                 if (!IS_ERR(inode)) {
 561                         key_put(key);
 562                         goto success;
 563                 }
 564
 565                 ret = PTR_ERR(inode);
 566                 key_put(key);
 567                 if (ret == -ENOENT) {
 568                         d_add(dentry, NULL);
 569                         _leave(" = NULL [negative]");
 570                         return NULL;
 571                 }
 572                 _leave(" = %d [do]", ret);
 573                 return ERR_PTR(ret);
 574         }
 575         dentry->d_fsdata = (void *)(unsigned long) vnode->status.data_version;
 576
 577         /* instantiate the dentry */
 578         inode = afs_iget(dir->i_sb, key, &fid, NULL, NULL);
 579         key_put(key);
 580         if (IS_ERR(inode)) {
 581                 _leave(" = %ld", PTR_ERR(inode));
 582                 return ERR_CAST(inode);
 583         }
 584
 585 success:
 586         d_add(dentry, inode);
 587         _leave(" = 0 { vn=%u u=%u } -> { ino=%lu v=%u }",
 588                fid.vnode,
 589                fid.unique,
 590                dentry->d_inode->i_ino,
 591                dentry->d_inode->i_generation);
 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         if (nd->flags & LOOKUP_RCU)
 611                 return -ECHILD;
 612
 613         vnode = AFS_FS_I(dentry->d_inode);
 614
 615         if (dentry->d_inode)
 616                 _enter("{v={%x:%u} n=%s fl=%lx},",
 617                        vnode->fid.vid, vnode->fid.vnode, dentry->d_name.name,
 618                        vnode->flags);
 619         else
 620                 _enter("{neg n=%s}", dentry->d_name.name);
 621
 622         key = afs_request_key(AFS_FS_S(dentry->d_sb)->volume->cell);
 623         if (IS_ERR(key))
 624                 key = NULL;
 625
 626         /* lock down the parent dentry so we can peer at it */
 627         parent = dget_parent(dentry);
 628         if (!parent->d_inode)
 629                 goto out_bad;
 630
 631         dir = AFS_FS_I(parent->d_inode);
 632
 633         /* validate the parent directory */
 634         if (test_bit(AFS_VNODE_MODIFIED, &dir->flags))
 635                 afs_validate(dir, key);
 636
 637         if (test_bit(AFS_VNODE_DELETED, &dir->flags)) {
 638                 _debug("%s: parent dir deleted", dentry->d_name.name);
 639                 goto out_bad;
 640         }
 641
 642         dir_version = (void *) (unsigned long) dir->status.data_version;
 643         if (dentry->d_fsdata == dir_version)
 644                 goto out_valid; /* the dir contents are unchanged */
 645
 646         _debug("dir modified");
 647
 648         /* search the directory for this vnode */
 649         ret = afs_do_lookup(&dir->vfs_inode, dentry, &fid, key);
 650         switch (ret) {
 651         case 0:
 652                 /* the filename maps to something */
 653                 if (!dentry->d_inode)
 654                         goto out_bad;
 655                 if (is_bad_inode(dentry->d_inode)) {
 656                         printk("kAFS: afs_d_revalidate: %s/%s has bad inode\n",
 657                                parent->d_name.name, dentry->d_name.name);
 658                         goto out_bad;
 659                 }
 660
 661                 /* if the vnode ID has changed, then the dirent points to a
 662                  * different file */
 663                 if (fid.vnode != vnode->fid.vnode) {
 664                         _debug("%s: dirent changed [%u != %u]",
 665                                dentry->d_name.name, fid.vnode,
 666                                vnode->fid.vnode);
 667                         goto not_found;
 668                 }
 669
 670                 /* if the vnode ID uniqifier has changed, then the file has
 671                  * been deleted and replaced, and the original vnode ID has
 672                  * been reused */
 673                 if (fid.unique != vnode->fid.unique) {
 674                         _debug("%s: file deleted (uq %u -> %u I:%u)",
 675                                dentry->d_name.name, fid.unique,
 676                                vnode->fid.unique,
 677                                dentry->d_inode->i_generation);
 678                         spin_lock(&vnode->lock);
 679                         set_bit(AFS_VNODE_DELETED, &vnode->flags);
 680                         spin_unlock(&vnode->lock);
 681                         goto not_found;
 682                 }
 683                 goto out_valid;
 684
 685         case -ENOENT:
 686                 /* the filename is unknown */
 687                 _debug("%s: dirent not found", dentry->d_name.name);
 688                 if (dentry->d_inode)
 689                         goto not_found;
 690                 goto out_valid;
 691
 692         default:
 693                 _debug("failed to iterate dir %s: %d",
 694                        parent->d_name.name, ret);
 695                 goto out_bad;
 696         }
 697
 698 out_valid:
 699         dentry->d_fsdata = dir_version;
 700 out_skip:
 701         dput(parent);
 702         key_put(key);
 703         _leave(" = 1 [valid]");
 704         return 1;
 705
 706         /* the dirent, if it exists, now points to a different vnode */
 707 not_found:
 708         spin_lock(&dentry->d_lock);
 709         dentry->d_flags |= DCACHE_NFSFS_RENAMED;
 710         spin_unlock(&dentry->d_lock);
 711
 712 out_bad:
 713         if (dentry->d_inode) {
 714                 /* don't unhash if we have submounts */
 715                 if (have_submounts(dentry))
 716                         goto out_skip;
 717         }
 718
 719         _debug("dropping dentry %s/%s",
 720                parent->d_name.name, dentry->d_name.name);
 721         shrink_dcache_parent(dentry);
 722         d_drop(dentry);
 723         dput(parent);
 724         key_put(key);
 725
 726         _leave(" = 0 [bad]");
 727         return 0;
 728 }
 729
 730 /*
 731  * allow the VFS to enquire as to whether a dentry should be unhashed (mustn't
 732  * sleep)
 733  * - called from dput() when d_count is going to 0.
 734  * - return 1 to request dentry be unhashed, 0 otherwise
 735  */
 736 static int afs_d_delete(const struct dentry *dentry)
 737 {
 738         _enter("%s", dentry->d_name.name);
 739
 740         if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
 741                 goto zap;
 742
 743         if (dentry->d_inode &&
 744             (test_bit(AFS_VNODE_DELETED,   &AFS_FS_I(dentry->d_inode)->flags) ||
 745              test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(dentry->d_inode)->flags)))
 746                 goto zap;
 747
 748         _leave(" = 0 [keep]");
 749         return 0;
 750
 751 zap:
 752         _leave(" = 1 [zap]");
 753         return 1;
 754 }
 755
 756 /*
 757  * handle dentry release
 758  */
 759 static void afs_d_release(struct dentry *dentry)
 760 {
 761         _enter("%s", dentry->d_name.name);
 762 }
 763
 764 /*
 765  * create a directory on an AFS filesystem
 766  */
 767 static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 768 {
 769         struct afs_file_status status;
 770         struct afs_callback cb;
 771         struct afs_server *server;
 772         struct afs_vnode *dvnode, *vnode;
 773         struct afs_fid fid;
 774         struct inode *inode;
 775         struct key *key;
 776         int ret;
 777
 778         dvnode = AFS_FS_I(dir);
 779
 780         _enter("{%x:%u},{%s},%ho",
 781                dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name, mode);
 782
 783         ret = -ENAMETOOLONG;
 784         if (dentry->d_name.len >= AFSNAMEMAX)
 785                 goto error;
 786
 787         key = afs_request_key(dvnode->volume->cell);
 788         if (IS_ERR(key)) {
 789                 ret = PTR_ERR(key);
 790                 goto error;
 791         }
 792
 793         mode |= S_IFDIR;
 794         ret = afs_vnode_create(dvnode, key, dentry->d_name.name,
 795                                mode, &fid, &status, &cb, &server);
 796         if (ret < 0)
 797                 goto mkdir_error;
 798
 799         inode = afs_iget(dir->i_sb, key, &fid, &status, &cb);
 800         if (IS_ERR(inode)) {
 801                 /* ENOMEM at a really inconvenient time - just abandon the new
 802                  * directory on the server */
 803                 ret = PTR_ERR(inode);
 804                 goto iget_error;
 805         }
 806
 807         /* apply the status report we've got for the new vnode */
 808         vnode = AFS_FS_I(inode);
 809         spin_lock(&vnode->lock);
 810         vnode->update_cnt++;
 811         spin_unlock(&vnode->lock);
 812         afs_vnode_finalise_status_update(vnode, server);
 813         afs_put_server(server);
 814
 815         d_instantiate(dentry, inode);
 816         if (d_unhashed(dentry)) {
 817                 _debug("not hashed");
 818                 d_rehash(dentry);
 819         }
 820         key_put(key);
 821         _leave(" = 0");
 822         return 0;
 823
 824 iget_error:
 825         afs_put_server(server);
 826 mkdir_error:
 827         key_put(key);
 828 error:
 829         d_drop(dentry);
 830         _leave(" = %d", ret);
 831         return ret;
 832 }
 833
 834 /*
 835  * remove a directory from an AFS filesystem
 836  */
 837 static int afs_rmdir(struct inode *dir, struct dentry *dentry)
 838 {
 839         struct afs_vnode *dvnode, *vnode;
 840         struct key *key;
 841         int ret;
 842
 843         dvnode = AFS_FS_I(dir);
 844
 845         _enter("{%x:%u},{%s}",
 846                dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name);
 847
 848         ret = -ENAMETOOLONG;
 849         if (dentry->d_name.len >= AFSNAMEMAX)
 850                 goto error;
 851
 852         key = afs_request_key(dvnode->volume->cell);
 853         if (IS_ERR(key)) {
 854                 ret = PTR_ERR(key);
 855                 goto error;
 856         }
 857
 858         ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, true);
 859         if (ret < 0)
 860                 goto rmdir_error;
 861
 862         if (dentry->d_inode) {
 863                 vnode = AFS_FS_I(dentry->d_inode);
 864                 clear_nlink(&vnode->vfs_inode);
 865                 set_bit(AFS_VNODE_DELETED, &vnode->flags);
 866                 afs_discard_callback_on_delete(vnode);
 867         }
 868
 869         key_put(key);
 870         _leave(" = 0");
 871         return 0;
 872
 873 rmdir_error:
 874         key_put(key);
 875 error:
 876         _leave(" = %d", ret);
 877         return ret;
 878 }
 879
 880 /*
 881  * remove a file from an AFS filesystem
 882  */
 883 static int afs_unlink(struct inode *dir, struct dentry *dentry)
 884 {
 885         struct afs_vnode *dvnode, *vnode;
 886         struct key *key;
 887         int ret;
 888
 889         dvnode = AFS_FS_I(dir);
 890
 891         _enter("{%x:%u},{%s}",
 892                dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name);
 893
 894         ret = -ENAMETOOLONG;
 895         if (dentry->d_name.len >= AFSNAMEMAX)
 896                 goto error;
 897
 898         key = afs_request_key(dvnode->volume->cell);
 899         if (IS_ERR(key)) {
 900                 ret = PTR_ERR(key);
 901                 goto error;
 902         }
 903
 904         if (dentry->d_inode) {
 905                 vnode = AFS_FS_I(dentry->d_inode);
 906
 907                 /* make sure we have a callback promise on the victim */
 908                 ret = afs_validate(vnode, key);
 909                 if (ret < 0)
 910                         goto error;
 911         }
 912
 913         ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, false);
 914         if (ret < 0)
 915                 goto remove_error;
 916
 917         if (dentry->d_inode) {
 918                 /* if the file wasn't deleted due to excess hard links, the
 919                  * fileserver will break the callback promise on the file - if
 920                  * it had one - before it returns to us, and if it was deleted,
 921                  * it won't
 922                  *
 923                  * however, if we didn't have a callback promise outstanding,
 924                  * or it was outstanding on a different server, then it won't
 925                  * break it either...
 926                  */
 927                 vnode = AFS_FS_I(dentry->d_inode);
 928                 if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
 929                         _debug("AFS_VNODE_DELETED");
 930                 if (test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags))
 931                         _debug("AFS_VNODE_CB_BROKEN");
 932                 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
 933                 ret = afs_validate(vnode, key);
 934                 _debug("nlink %d [val %d]", vnode->vfs_inode.i_nlink, ret);
 935         }
 936
 937         key_put(key);
 938         _leave(" = 0");
 939         return 0;
 940
 941 remove_error:
 942         key_put(key);
 943 error:
 944         _leave(" = %d", ret);
 945         return ret;
 946 }
 947
 948 /*
 949  * create a regular file on an AFS filesystem
 950  */
 951 static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 952                       struct nameidata *nd)
 953 {
 954         struct afs_file_status status;
 955         struct afs_callback cb;
 956         struct afs_server *server;
 957         struct afs_vnode *dvnode, *vnode;
 958         struct afs_fid fid;
 959         struct inode *inode;
 960         struct key *key;
 961         int ret;
 962
 963         dvnode = AFS_FS_I(dir);
 964
 965         _enter("{%x:%u},{%s},%ho,",
 966                dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name, mode);
 967
 968         ret = -ENAMETOOLONG;
 969         if (dentry->d_name.len >= AFSNAMEMAX)
 970                 goto error;
 971
 972         key = afs_request_key(dvnode->volume->cell);
 973         if (IS_ERR(key)) {
 974                 ret = PTR_ERR(key);
 975                 goto error;
 976         }
 977
 978         mode |= S_IFREG;
 979         ret = afs_vnode_create(dvnode, key, dentry->d_name.name,
 980                                mode, &fid, &status, &cb, &server);
 981         if (ret < 0)
 982                 goto create_error;
 983
 984         inode = afs_iget(dir->i_sb, key, &fid, &status, &cb);
 985         if (IS_ERR(inode)) {
 986                 /* ENOMEM at a really inconvenient time - just abandon the new
 987                  * directory on the server */
 988                 ret = PTR_ERR(inode);
 989                 goto iget_error;
 990         }
 991
 992         /* apply the status report we've got for the new vnode */
 993         vnode = AFS_FS_I(inode);
 994         spin_lock(&vnode->lock);
 995         vnode->update_cnt++;
 996         spin_unlock(&vnode->lock);
 997         afs_vnode_finalise_status_update(vnode, server);
 998         afs_put_server(server);
 999
1000         d_instantiate(dentry, inode);
1001         if (d_unhashed(dentry)) {
1002                 _debug("not hashed");
1003                 d_rehash(dentry);
1004         }
1005         key_put(key);
1006         _leave(" = 0");
1007         return 0;
1008
1009 iget_error:
1010         afs_put_server(server);
1011 create_error:
1012         key_put(key);
1013 error:
1014         d_drop(dentry);
1015         _leave(" = %d", ret);
1016         return ret;
1017 }
1018
1019 /*
1020  * create a hard link between files in an AFS filesystem
1021  */
1022 static int afs_link(struct dentry *from, struct inode *dir,
1023                     struct dentry *dentry)
1024 {
1025         struct afs_vnode *dvnode, *vnode;
1026         struct key *key;
1027         int ret;
1028
1029         vnode = AFS_FS_I(from->d_inode);
1030         dvnode = AFS_FS_I(dir);
1031
1032         _enter("{%x:%u},{%x:%u},{%s}",
1033                vnode->fid.vid, vnode->fid.vnode,
1034                dvnode->fid.vid, dvnode->fid.vnode,
1035                dentry->d_name.name);
1036
1037         ret = -ENAMETOOLONG;
1038         if (dentry->d_name.len >= AFSNAMEMAX)
1039                 goto error;
1040
1041         key = afs_request_key(dvnode->volume->cell);
1042         if (IS_ERR(key)) {
1043                 ret = PTR_ERR(key);
1044                 goto error;
1045         }
1046
1047         ret = afs_vnode_link(dvnode, vnode, key, dentry->d_name.name);
1048         if (ret < 0)
1049                 goto link_error;
1050
1051         ihold(&vnode->vfs_inode);
1052         d_instantiate(dentry, &vnode->vfs_inode);
1053         key_put(key);
1054         _leave(" = 0");
1055         return 0;
1056
1057 link_error:
1058         key_put(key);
1059 error:
1060         d_drop(dentry);
1061         _leave(" = %d", ret);
1062         return ret;
1063 }
1064
1065 /*
1066  * create a symlink in an AFS filesystem
1067  */
1068 static int afs_symlink(struct inode *dir, struct dentry *dentry,
1069                        const char *content)
1070 {
1071         struct afs_file_status status;
1072         struct afs_server *server;
1073         struct afs_vnode *dvnode, *vnode;
1074         struct afs_fid fid;
1075         struct inode *inode;
1076         struct key *key;
1077         int ret;
1078
1079         dvnode = AFS_FS_I(dir);
1080
1081         _enter("{%x:%u},{%s},%s",
1082                dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name,
1083                content);
1084
1085         ret = -ENAMETOOLONG;
1086         if (dentry->d_name.len >= AFSNAMEMAX)
1087                 goto error;
1088
1089         ret = -EINVAL;
1090         if (strlen(content) >= AFSPATHMAX)
1091                 goto error;
1092
1093         key = afs_request_key(dvnode->volume->cell);
1094         if (IS_ERR(key)) {
1095                 ret = PTR_ERR(key);
1096                 goto error;
1097         }
1098
1099         ret = afs_vnode_symlink(dvnode, key, dentry->d_name.name, content,
1100                                 &fid, &status, &server);
1101         if (ret < 0)
1102                 goto create_error;
1103
1104         inode = afs_iget(dir->i_sb, key, &fid, &status, NULL);
1105         if (IS_ERR(inode)) {
1106                 /* ENOMEM at a really inconvenient time - just abandon the new
1107                  * directory on the server */
1108                 ret = PTR_ERR(inode);
1109                 goto iget_error;
1110         }
1111
1112         /* apply the status report we've got for the new vnode */
1113         vnode = AFS_FS_I(inode);
1114         spin_lock(&vnode->lock);
1115         vnode->update_cnt++;
1116         spin_unlock(&vnode->lock);
1117         afs_vnode_finalise_status_update(vnode, server);
1118         afs_put_server(server);
1119
1120         d_instantiate(dentry, inode);
1121         if (d_unhashed(dentry)) {
1122                 _debug("not hashed");
1123                 d_rehash(dentry);
1124         }
1125         key_put(key);
1126         _leave(" = 0");
1127         return 0;
1128
1129 iget_error:
1130         afs_put_server(server);
1131 create_error:
1132         key_put(key);
1133 error:
1134         d_drop(dentry);
1135         _leave(" = %d", ret);
1136         return ret;
1137 }
1138
1139 /*
1140  * rename a file in an AFS filesystem and/or move it between directories
1141  */
1142 static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
1143                       struct inode *new_dir, struct dentry *new_dentry)
1144 {
1145         struct afs_vnode *orig_dvnode, *new_dvnode, *vnode;
1146         struct key *key;
1147         int ret;
1148
1149         vnode = AFS_FS_I(old_dentry->d_inode);
1150         orig_dvnode = AFS_FS_I(old_dir);
1151         new_dvnode = AFS_FS_I(new_dir);
1152
1153         _enter("{%x:%u},{%x:%u},{%x:%u},{%s}",
1154                orig_dvnode->fid.vid, orig_dvnode->fid.vnode,
1155                vnode->fid.vid, vnode->fid.vnode,
1156                new_dvnode->fid.vid, new_dvnode->fid.vnode,
1157                new_dentry->d_name.name);
1158
1159         ret = -ENAMETOOLONG;
1160         if (new_dentry->d_name.len >= AFSNAMEMAX)
1161                 goto error;
1162
1163         key = afs_request_key(orig_dvnode->volume->cell);
1164         if (IS_ERR(key)) {
1165                 ret = PTR_ERR(key);
1166                 goto error;
1167         }
1168
1169         ret = afs_vnode_rename(orig_dvnode, new_dvnode, key,
1170                                old_dentry->d_name.name,
1171                                new_dentry->d_name.name);
1172         if (ret < 0)
1173                 goto rename_error;
1174         key_put(key);
1175         _leave(" = 0");
1176         return 0;
1177
1178 rename_error:
1179         key_put(key);
1180 error:
1181         d_drop(new_dentry);
1182         _leave(" = %d", ret);
1183         return ret;
1184 }