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