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