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                                  unsigned int flags);
  24 static int afs_dir_open(struct inode *inode, struct file *file);
  25 static int afs_readdir(struct file *file, struct dir_context *ctx);
  26 static int afs_d_revalidate(struct dentry *dentry, unsigned int flags);
  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(struct dir_context *ctx, 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                       bool excl);
  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         .iterate        = 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 dir_context ctx;
 123         struct afs_fid  fid;
 124         struct qstr name;
 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(struct dir_context *ctx,
 232                                  union afs_dir_block *block,
 233                                  unsigned blkoff)
 234 {
 235         union afs_dirent *dire;
 236         unsigned offset, next, curr;
 237         size_t nlen;
 238         int tmp;
 239
 240         _enter("%u,%x,%p,,",(unsigned)ctx->pos,blkoff,block);
 241
 242         curr = (ctx->pos - blkoff) / sizeof(union afs_dirent);
 243
 244         /* walk through the block, an entry at a time */
 245         for (offset = AFS_DIRENT_PER_BLOCK - block->pagehdr.nentries;
 246              offset < AFS_DIRENT_PER_BLOCK;
 247              offset = next
 248              ) {
 249                 next = offset + 1;
 250
 251                 /* skip entries marked unused in the bitmap */
 252                 if (!(block->pagehdr.bitmap[offset / 8] &
 253                       (1 << (offset % 8)))) {
 254                         _debug("ENT[%Zu.%u]: unused",
 255                                blkoff / sizeof(union afs_dir_block), offset);
 256                         if (offset >= curr)
 257                                 ctx->pos = blkoff +
 258                                         next * sizeof(union afs_dirent);
 259                         continue;
 260                 }
 261
 262                 /* got a valid entry */
 263                 dire = &block->dirents[offset];
 264                 nlen = strnlen(dire->u.name,
 265                                sizeof(*block) -
 266                                offset * sizeof(union afs_dirent));
 267
 268                 _debug("ENT[%Zu.%u]: %s %Zu \"%s\"",
 269                        blkoff / sizeof(union afs_dir_block), offset,
 270                        (offset < curr ? "skip" : "fill"),
 271                        nlen, dire->u.name);
 272
 273                 /* work out where the next possible entry is */
 274                 for (tmp = nlen; tmp > 15; tmp -= sizeof(union afs_dirent)) {
 275                         if (next >= AFS_DIRENT_PER_BLOCK) {
 276                                 _debug("ENT[%Zu.%u]:"
 277                                        " %u travelled beyond end dir block"
 278                                        " (len %u/%Zu)",
 279                                        blkoff / sizeof(union afs_dir_block),
 280                                        offset, next, tmp, nlen);
 281                                 return -EIO;
 282                         }
 283                         if (!(block->pagehdr.bitmap[next / 8] &
 284                               (1 << (next % 8)))) {
 285                                 _debug("ENT[%Zu.%u]:"
 286                                        " %u unmarked extension (len %u/%Zu)",
 287                                        blkoff / sizeof(union afs_dir_block),
 288                                        offset, next, tmp, nlen);
 289                                 return -EIO;
 290                         }
 291
 292                         _debug("ENT[%Zu.%u]: ext %u/%Zu",
 293                                blkoff / sizeof(union afs_dir_block),
 294                                next, tmp, nlen);
 295                         next++;
 296                 }
 297
 298                 /* skip if starts before the current position */
 299                 if (offset < curr)
 300                         continue;
 301
 302                 /* found the next entry */
 303                 if (!dir_emit(ctx, dire->u.name, nlen,
 304                               ntohl(dire->u.vnode),
 305                               ctx->actor == afs_lookup_filldir ?
 306                               ntohl(dire->u.unique) : DT_UNKNOWN)) {
 307                         _leave(" = 0 [full]");
 308                         return 0;
 309                 }
 310
 311                 ctx->pos = blkoff + next * sizeof(union afs_dirent);
 312         }
 313
 314         _leave(" = 1 [more]");
 315         return 1;
 316 }
 317
 318 /*
 319  * iterate through the data blob that lists the contents of an AFS directory
 320  */
 321 static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx,
 322                            struct key *key)
 323 {
 324         union afs_dir_block *dblock;
 325         struct afs_dir_page *dbuf;
 326         struct page *page;
 327         unsigned blkoff, limit;
 328         int ret;
 329
 330         _enter("{%lu},%u,,", dir->i_ino, (unsigned)ctx->pos);
 331
 332         if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(dir)->flags)) {
 333                 _leave(" = -ESTALE");
 334                 return -ESTALE;
 335         }
 336
 337         /* round the file position up to the next entry boundary */
 338         ctx->pos += sizeof(union afs_dirent) - 1;
 339         ctx->pos &= ~(sizeof(union afs_dirent) - 1);
 340
 341         /* walk through the blocks in sequence */
 342         ret = 0;
 343         while (ctx->pos < dir->i_size) {
 344                 blkoff = ctx->pos & ~(sizeof(union afs_dir_block) - 1);
 345
 346                 /* fetch the appropriate page from the directory */
 347                 page = afs_dir_get_page(dir, blkoff / PAGE_SIZE, key);
 348                 if (IS_ERR(page)) {
 349                         ret = PTR_ERR(page);
 350                         break;
 351                 }
 352
 353                 limit = blkoff & ~(PAGE_SIZE - 1);
 354
 355                 dbuf = page_address(page);
 356
 357                 /* deal with the individual blocks stashed on this page */
 358                 do {
 359                         dblock = &dbuf->blocks[(blkoff % PAGE_SIZE) /
 360                                                sizeof(union afs_dir_block)];
 361                         ret = afs_dir_iterate_block(ctx, dblock, blkoff);
 362                         if (ret != 1) {
 363                                 afs_dir_put_page(page);
 364                                 goto out;
 365                         }
 366
 367                         blkoff += sizeof(union afs_dir_block);
 368
 369                 } while (ctx->pos < dir->i_size && blkoff < limit);
 370
 371                 afs_dir_put_page(page);
 372                 ret = 0;
 373         }
 374
 375 out:
 376         _leave(" = %d", ret);
 377         return ret;
 378 }
 379
 380 /*
 381  * read an AFS directory
 382  */
 383 static int afs_readdir(struct file *file, struct dir_context *ctx)
 384 {
 385         return afs_dir_iterate(file_inode(file),
 386                               ctx, file->private_data);
 387 }
 388
 389 /*
 390  * search the directory for a name
 391  * - if afs_dir_iterate_block() spots this function, it'll pass the FID
 392  *   uniquifier through dtype
 393  */
 394 static int afs_lookup_filldir(struct dir_context *ctx, const char *name,
 395                               int nlen, loff_t fpos, u64 ino, unsigned dtype)
 396 {
 397         struct afs_lookup_cookie *cookie =
 398                 container_of(ctx, struct afs_lookup_cookie, ctx);
 399
 400         _enter("{%s,%u},%s,%u,,%llu,%u",
 401                cookie->name.name, cookie->name.len, name, nlen,
 402                (unsigned long long) ino, dtype);
 403
 404         /* insanity checks first */
 405         BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048);
 406         BUILD_BUG_ON(sizeof(union afs_dirent) != 32);
 407
 408         if (cookie->name.len != nlen ||
 409             memcmp(cookie->name.name, name, nlen) != 0) {
 410                 _leave(" = 0 [no]");
 411                 return 0;
 412         }
 413
 414         cookie->fid.vnode = ino;
 415         cookie->fid.unique = dtype;
 416         cookie->found = 1;
 417
 418         _leave(" = -1 [found]");
 419         return -1;
 420 }
 421
 422 /*
 423  * do a lookup in a directory
 424  * - just returns the FID the dentry name maps to if found
 425  */
 426 static int afs_do_lookup(struct inode *dir, struct dentry *dentry,
 427                          struct afs_fid *fid, struct key *key)
 428 {
 429         struct afs_super_info *as = dir->i_sb->s_fs_info;
 430         struct afs_lookup_cookie cookie = {
 431                 .ctx.actor = afs_lookup_filldir,
 432                 .name = dentry->d_name,
 433                 .fid.vid = as->volume->vid
 434         };
 435         int ret;
 436
 437         _enter("{%lu},%p{%pd},", dir->i_ino, dentry, dentry);
 438
 439         /* search the directory */
 440         ret = afs_dir_iterate(dir, &cookie.ctx, key);
 441         if (ret < 0) {
 442                 _leave(" = %d [iter]", ret);
 443                 return ret;
 444         }
 445
 446         ret = -ENOENT;
 447         if (!cookie.found) {
 448                 _leave(" = -ENOENT [not found]");
 449                 return -ENOENT;
 450         }
 451
 452         *fid = cookie.fid;
 453         _leave(" = 0 { vn=%u u=%u }", fid->vnode, fid->unique);
 454         return 0;
 455 }
 456
 457 /*
 458  * Try to auto mount the mountpoint with pseudo directory, if the autocell
 459  * operation is setted.
 460  */
 461 static struct inode *afs_try_auto_mntpt(
 462         int ret, struct dentry *dentry, struct inode *dir, struct key *key,
 463         struct afs_fid *fid)
 464 {
 465         const char *devname = dentry->d_name.name;
 466         struct afs_vnode *vnode = AFS_FS_I(dir);
 467         struct inode *inode;
 468
 469         _enter("%d, %p{%pd}, {%x:%u}, %p",
 470                ret, dentry, dentry, vnode->fid.vid, vnode->fid.vnode, key);
 471
 472         if (ret != -ENOENT ||
 473             !test_bit(AFS_VNODE_AUTOCELL, &vnode->flags))
 474                 goto out;
 475
 476         inode = afs_iget_autocell(dir, devname, strlen(devname), key);
 477         if (IS_ERR(inode)) {
 478                 ret = PTR_ERR(inode);
 479                 goto out;
 480         }
 481
 482         *fid = AFS_FS_I(inode)->fid;
 483         _leave("= %p", inode);
 484         return inode;
 485
 486 out:
 487         _leave("= %d", ret);
 488         return ERR_PTR(ret);
 489 }
 490
 491 /*
 492  * look up an entry in a directory
 493  */
 494 static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
 495                                  unsigned int flags)
 496 {
 497         struct afs_vnode *vnode;
 498         struct afs_fid fid;
 499         struct inode *inode;
 500         struct key *key;
 501         int ret;
 502
 503         vnode = AFS_FS_I(dir);
 504
 505         _enter("{%x:%u},%p{%pd},",
 506                vnode->fid.vid, vnode->fid.vnode, dentry, dentry);
 507
 508         ASSERTCMP(d_inode(dentry), ==, NULL);
 509
 510         if (dentry->d_name.len >= AFSNAMEMAX) {
 511                 _leave(" = -ENAMETOOLONG");
 512                 return ERR_PTR(-ENAMETOOLONG);
 513         }
 514
 515         if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
 516                 _leave(" = -ESTALE");
 517                 return ERR_PTR(-ESTALE);
 518         }
 519
 520         key = afs_request_key(vnode->volume->cell);
 521         if (IS_ERR(key)) {
 522                 _leave(" = %ld [key]", PTR_ERR(key));
 523                 return ERR_CAST(key);
 524         }
 525
 526         ret = afs_validate(vnode, key);
 527         if (ret < 0) {
 528                 key_put(key);
 529                 _leave(" = %d [val]", ret);
 530                 return ERR_PTR(ret);
 531         }
 532
 533         ret = afs_do_lookup(dir, dentry, &fid, key);
 534         if (ret < 0) {
 535                 inode = afs_try_auto_mntpt(ret, dentry, dir, key, &fid);
 536                 if (!IS_ERR(inode)) {
 537                         key_put(key);
 538                         goto success;
 539                 }
 540
 541                 ret = PTR_ERR(inode);
 542                 key_put(key);
 543                 if (ret == -ENOENT) {
 544                         d_add(dentry, NULL);
 545                         _leave(" = NULL [negative]");
 546                         return NULL;
 547                 }
 548                 _leave(" = %d [do]", ret);
 549                 return ERR_PTR(ret);
 550         }
 551         dentry->d_fsdata = (void *)(unsigned long) vnode->status.data_version;
 552
 553         /* instantiate the dentry */
 554         inode = afs_iget(dir->i_sb, key, &fid, NULL, NULL);
 555         key_put(key);
 556         if (IS_ERR(inode)) {
 557                 _leave(" = %ld", PTR_ERR(inode));
 558                 return ERR_CAST(inode);
 559         }
 560
 561 success:
 562         d_add(dentry, inode);
 563         _leave(" = 0 { vn=%u u=%u } -> { ino=%lu v=%u }",
 564                fid.vnode,
 565                fid.unique,
 566                d_inode(dentry)->i_ino,
 567                d_inode(dentry)->i_generation);
 568
 569         return NULL;
 570 }
 571
 572 /*
 573  * check that a dentry lookup hit has found a valid entry
 574  * - NOTE! the hit can be a negative hit too, so we can't assume we have an
 575  *   inode
 576  */
 577 static int afs_d_revalidate(struct dentry *dentry, unsigned int flags)
 578 {
 579         struct afs_vnode *vnode, *dir;
 580         struct afs_fid uninitialized_var(fid);
 581         struct dentry *parent;
 582         struct key *key;
 583         void *dir_version;
 584         int ret;
 585
 586         if (flags & LOOKUP_RCU)
 587                 return -ECHILD;
 588
 589         vnode = AFS_FS_I(d_inode(dentry));
 590
 591         if (d_really_is_positive(dentry))
 592                 _enter("{v={%x:%u} n=%pd fl=%lx},",
 593                        vnode->fid.vid, vnode->fid.vnode, dentry,
 594                        vnode->flags);
 595         else
 596                 _enter("{neg n=%pd}", dentry);
 597
 598         key = afs_request_key(AFS_FS_S(dentry->d_sb)->volume->cell);
 599         if (IS_ERR(key))
 600                 key = NULL;
 601
 602         /* lock down the parent dentry so we can peer at it */
 603         parent = dget_parent(dentry);
 604         dir = AFS_FS_I(d_inode(parent));
 605
 606         /* validate the parent directory */
 607         if (test_bit(AFS_VNODE_MODIFIED, &dir->flags))
 608                 afs_validate(dir, key);
 609
 610         if (test_bit(AFS_VNODE_DELETED, &dir->flags)) {
 611                 _debug("%pd: parent dir deleted", dentry);
 612                 goto out_bad;
 613         }
 614
 615         dir_version = (void *) (unsigned long) dir->status.data_version;
 616         if (dentry->d_fsdata == dir_version)
 617                 goto out_valid; /* the dir contents are unchanged */
 618
 619         _debug("dir modified");
 620
 621         /* search the directory for this vnode */
 622         ret = afs_do_lookup(&dir->vfs_inode, dentry, &fid, key);
 623         switch (ret) {
 624         case 0:
 625                 /* the filename maps to something */
 626                 if (d_really_is_negative(dentry))
 627                         goto out_bad;
 628                 if (is_bad_inode(d_inode(dentry))) {
 629                         printk("kAFS: afs_d_revalidate: %pd2 has bad inode\n",
 630                                dentry);
 631                         goto out_bad;
 632                 }
 633
 634                 /* if the vnode ID has changed, then the dirent points to a
 635                  * different file */
 636                 if (fid.vnode != vnode->fid.vnode) {
 637                         _debug("%pd: dirent changed [%u != %u]",
 638                                dentry, fid.vnode,
 639                                vnode->fid.vnode);
 640                         goto not_found;
 641                 }
 642
 643                 /* if the vnode ID uniqifier has changed, then the file has
 644                  * been deleted and replaced, and the original vnode ID has
 645                  * been reused */
 646                 if (fid.unique != vnode->fid.unique) {
 647                         _debug("%pd: file deleted (uq %u -> %u I:%u)",
 648                                dentry, fid.unique,
 649                                vnode->fid.unique,
 650                                d_inode(dentry)->i_generation);
 651                         spin_lock(&vnode->lock);
 652                         set_bit(AFS_VNODE_DELETED, &vnode->flags);
 653                         spin_unlock(&vnode->lock);
 654                         goto not_found;
 655                 }
 656                 goto out_valid;
 657
 658         case -ENOENT:
 659                 /* the filename is unknown */
 660                 _debug("%pd: dirent not found", dentry);
 661                 if (d_really_is_positive(dentry))
 662                         goto not_found;
 663                 goto out_valid;
 664
 665         default:
 666                 _debug("failed to iterate dir %pd: %d",
 667                        parent, ret);
 668                 goto out_bad;
 669         }
 670
 671 out_valid:
 672         dentry->d_fsdata = dir_version;
 673         dput(parent);
 674         key_put(key);
 675         _leave(" = 1 [valid]");
 676         return 1;
 677
 678         /* the dirent, if it exists, now points to a different vnode */
 679 not_found:
 680         spin_lock(&dentry->d_lock);
 681         dentry->d_flags |= DCACHE_NFSFS_RENAMED;
 682         spin_unlock(&dentry->d_lock);
 683
 684 out_bad:
 685         _debug("dropping dentry %pd2", dentry);
 686         dput(parent);
 687         key_put(key);
 688
 689         _leave(" = 0 [bad]");
 690         return 0;
 691 }
 692
 693 /*
 694  * allow the VFS to enquire as to whether a dentry should be unhashed (mustn't
 695  * sleep)
 696  * - called from dput() when d_count is going to 0.
 697  * - return 1 to request dentry be unhashed, 0 otherwise
 698  */
 699 static int afs_d_delete(const struct dentry *dentry)
 700 {
 701         _enter("%pd", dentry);
 702
 703         if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
 704                 goto zap;
 705
 706         if (d_really_is_positive(dentry) &&
 707             (test_bit(AFS_VNODE_DELETED,   &AFS_FS_I(d_inode(dentry))->flags) ||
 708              test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(d_inode(dentry))->flags)))
 709                 goto zap;
 710
 711         _leave(" = 0 [keep]");
 712         return 0;
 713
 714 zap:
 715         _leave(" = 1 [zap]");
 716         return 1;
 717 }
 718
 719 /*
 720  * handle dentry release
 721  */
 722 static void afs_d_release(struct dentry *dentry)
 723 {
 724         _enter("%pd", dentry);
 725 }
 726
 727 /*
 728  * create a directory on an AFS filesystem
 729  */
 730 static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 731 {
 732         struct afs_file_status status;
 733         struct afs_callback cb;
 734         struct afs_server *server;
 735         struct afs_vnode *dvnode, *vnode;
 736         struct afs_fid fid;
 737         struct inode *inode;
 738         struct key *key;
 739         int ret;
 740
 741         dvnode = AFS_FS_I(dir);
 742
 743         _enter("{%x:%u},{%pd},%ho",
 744                dvnode->fid.vid, dvnode->fid.vnode, dentry, mode);
 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},{%pd}",
 805                dvnode->fid.vid, dvnode->fid.vnode, dentry);
 806
 807         key = afs_request_key(dvnode->volume->cell);
 808         if (IS_ERR(key)) {
 809                 ret = PTR_ERR(key);
 810                 goto error;
 811         }
 812
 813         ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, true);
 814         if (ret < 0)
 815                 goto rmdir_error;
 816
 817         if (d_really_is_positive(dentry)) {
 818                 vnode = AFS_FS_I(d_inode(dentry));
 819                 clear_nlink(&vnode->vfs_inode);
 820                 set_bit(AFS_VNODE_DELETED, &vnode->flags);
 821                 afs_discard_callback_on_delete(vnode);
 822         }
 823
 824         key_put(key);
 825         _leave(" = 0");
 826         return 0;
 827
 828 rmdir_error:
 829         key_put(key);
 830 error:
 831         _leave(" = %d", ret);
 832         return ret;
 833 }
 834
 835 /*
 836  * remove a file from an AFS filesystem
 837  */
 838 static int afs_unlink(struct inode *dir, struct dentry *dentry)
 839 {
 840         struct afs_vnode *dvnode, *vnode;
 841         struct key *key;
 842         int ret;
 843
 844         dvnode = AFS_FS_I(dir);
 845
 846         _enter("{%x:%u},{%pd}",
 847                dvnode->fid.vid, dvnode->fid.vnode, dentry);
 848
 849         ret = -ENAMETOOLONG;
 850         if (dentry->d_name.len >= AFSNAMEMAX)
 851                 goto error;
 852
 853         key = afs_request_key(dvnode->volume->cell);
 854         if (IS_ERR(key)) {
 855                 ret = PTR_ERR(key);
 856                 goto error;
 857         }
 858
 859         if (d_really_is_positive(dentry)) {
 860                 vnode = AFS_FS_I(d_inode(dentry));
 861
 862                 /* make sure we have a callback promise on the victim */
 863                 ret = afs_validate(vnode, key);
 864                 if (ret < 0)
 865                         goto error;
 866         }
 867
 868         ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, false);
 869         if (ret < 0)
 870                 goto remove_error;
 871
 872         if (d_really_is_positive(dentry)) {
 873                 /* if the file wasn't deleted due to excess hard links, the
 874                  * fileserver will break the callback promise on the file - if
 875                  * it had one - before it returns to us, and if it was deleted,
 876                  * it won't
 877                  *
 878                  * however, if we didn't have a callback promise outstanding,
 879                  * or it was outstanding on a different server, then it won't
 880                  * break it either...
 881                  */
 882                 vnode = AFS_FS_I(d_inode(dentry));
 883                 if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
 884                         _debug("AFS_VNODE_DELETED");
 885                 if (test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags))
 886                         _debug("AFS_VNODE_CB_BROKEN");
 887                 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
 888                 ret = afs_validate(vnode, key);
 889                 _debug("nlink %d [val %d]", vnode->vfs_inode.i_nlink, ret);
 890         }
 891
 892         key_put(key);
 893         _leave(" = 0");
 894         return 0;
 895
 896 remove_error:
 897         key_put(key);
 898 error:
 899         _leave(" = %d", ret);
 900         return ret;
 901 }
 902
 903 /*
 904  * create a regular file on an AFS filesystem
 905  */
 906 static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 907                       bool excl)
 908 {
 909         struct afs_file_status status;
 910         struct afs_callback cb;
 911         struct afs_server *server;
 912         struct afs_vnode *dvnode, *vnode;
 913         struct afs_fid fid;
 914         struct inode *inode;
 915         struct key *key;
 916         int ret;
 917
 918         dvnode = AFS_FS_I(dir);
 919
 920         _enter("{%x:%u},{%pd},%ho,",
 921                dvnode->fid.vid, dvnode->fid.vnode, dentry, mode);
 922
 923         key = afs_request_key(dvnode->volume->cell);
 924         if (IS_ERR(key)) {
 925                 ret = PTR_ERR(key);
 926                 goto error;
 927         }
 928
 929         mode |= S_IFREG;
 930         ret = afs_vnode_create(dvnode, key, dentry->d_name.name,
 931                                mode, &fid, &status, &cb, &server);
 932         if (ret < 0)
 933                 goto create_error;
 934
 935         inode = afs_iget(dir->i_sb, key, &fid, &status, &cb);
 936         if (IS_ERR(inode)) {
 937                 /* ENOMEM at a really inconvenient time - just abandon the new
 938                  * directory on the server */
 939                 ret = PTR_ERR(inode);
 940                 goto iget_error;
 941         }
 942
 943         /* apply the status report we've got for the new vnode */
 944         vnode = AFS_FS_I(inode);
 945         spin_lock(&vnode->lock);
 946         vnode->update_cnt++;
 947         spin_unlock(&vnode->lock);
 948         afs_vnode_finalise_status_update(vnode, server);
 949         afs_put_server(server);
 950
 951         d_instantiate(dentry, inode);
 952         if (d_unhashed(dentry)) {
 953                 _debug("not hashed");
 954                 d_rehash(dentry);
 955         }
 956         key_put(key);
 957         _leave(" = 0");
 958         return 0;
 959
 960 iget_error:
 961         afs_put_server(server);
 962 create_error:
 963         key_put(key);
 964 error:
 965         d_drop(dentry);
 966         _leave(" = %d", ret);
 967         return ret;
 968 }
 969
 970 /*
 971  * create a hard link between files in an AFS filesystem
 972  */
 973 static int afs_link(struct dentry *from, struct inode *dir,
 974                     struct dentry *dentry)
 975 {
 976         struct afs_vnode *dvnode, *vnode;
 977         struct key *key;
 978         int ret;
 979
 980         vnode = AFS_FS_I(d_inode(from));
 981         dvnode = AFS_FS_I(dir);
 982
 983         _enter("{%x:%u},{%x:%u},{%pd}",
 984                vnode->fid.vid, vnode->fid.vnode,
 985                dvnode->fid.vid, dvnode->fid.vnode,
 986                dentry);
 987
 988         key = afs_request_key(dvnode->volume->cell);
 989         if (IS_ERR(key)) {
 990                 ret = PTR_ERR(key);
 991                 goto error;
 992         }
 993
 994         ret = afs_vnode_link(dvnode, vnode, key, dentry->d_name.name);
 995         if (ret < 0)
 996                 goto link_error;
 997
 998         ihold(&vnode->vfs_inode);
 999         d_instantiate(dentry, &vnode->vfs_inode);
1000         key_put(key);
1001         _leave(" = 0");
1002         return 0;
1003
1004 link_error:
1005         key_put(key);
1006 error:
1007         d_drop(dentry);
1008         _leave(" = %d", ret);
1009         return ret;
1010 }
1011
1012 /*
1013  * create a symlink in an AFS filesystem
1014  */
1015 static int afs_symlink(struct inode *dir, struct dentry *dentry,
1016                        const char *content)
1017 {
1018         struct afs_file_status status;
1019         struct afs_server *server;
1020         struct afs_vnode *dvnode, *vnode;
1021         struct afs_fid fid;
1022         struct inode *inode;
1023         struct key *key;
1024         int ret;
1025
1026         dvnode = AFS_FS_I(dir);
1027
1028         _enter("{%x:%u},{%pd},%s",
1029                dvnode->fid.vid, dvnode->fid.vnode, dentry,
1030                content);
1031
1032         ret = -EINVAL;
1033         if (strlen(content) >= AFSPATHMAX)
1034                 goto error;
1035
1036         key = afs_request_key(dvnode->volume->cell);
1037         if (IS_ERR(key)) {
1038                 ret = PTR_ERR(key);
1039                 goto error;
1040         }
1041
1042         ret = afs_vnode_symlink(dvnode, key, dentry->d_name.name, content,
1043                                 &fid, &status, &server);
1044         if (ret < 0)
1045                 goto create_error;
1046
1047         inode = afs_iget(dir->i_sb, key, &fid, &status, NULL);
1048         if (IS_ERR(inode)) {
1049                 /* ENOMEM at a really inconvenient time - just abandon the new
1050                  * directory on the server */
1051                 ret = PTR_ERR(inode);
1052                 goto iget_error;
1053         }
1054
1055         /* apply the status report we've got for the new vnode */
1056         vnode = AFS_FS_I(inode);
1057         spin_lock(&vnode->lock);
1058         vnode->update_cnt++;
1059         spin_unlock(&vnode->lock);
1060         afs_vnode_finalise_status_update(vnode, server);
1061         afs_put_server(server);
1062
1063         d_instantiate(dentry, inode);
1064         if (d_unhashed(dentry)) {
1065                 _debug("not hashed");
1066                 d_rehash(dentry);
1067         }
1068         key_put(key);
1069         _leave(" = 0");
1070         return 0;
1071
1072 iget_error:
1073         afs_put_server(server);
1074 create_error:
1075         key_put(key);
1076 error:
1077         d_drop(dentry);
1078         _leave(" = %d", ret);
1079         return ret;
1080 }
1081
1082 /*
1083  * rename a file in an AFS filesystem and/or move it between directories
1084  */
1085 static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
1086                       struct inode *new_dir, struct dentry *new_dentry)
1087 {
1088         struct afs_vnode *orig_dvnode, *new_dvnode, *vnode;
1089         struct key *key;
1090         int ret;
1091
1092         vnode = AFS_FS_I(d_inode(old_dentry));
1093         orig_dvnode = AFS_FS_I(old_dir);
1094         new_dvnode = AFS_FS_I(new_dir);
1095
1096         _enter("{%x:%u},{%x:%u},{%x:%u},{%pd}",
1097                orig_dvnode->fid.vid, orig_dvnode->fid.vnode,
1098                vnode->fid.vid, vnode->fid.vnode,
1099                new_dvnode->fid.vid, new_dvnode->fid.vnode,
1100                new_dentry);
1101
1102         key = afs_request_key(orig_dvnode->volume->cell);
1103         if (IS_ERR(key)) {
1104                 ret = PTR_ERR(key);
1105                 goto error;
1106         }
1107
1108         ret = afs_vnode_rename(orig_dvnode, new_dvnode, key,
1109                                old_dentry->d_name.name,
1110                                new_dentry->d_name.name);
1111         if (ret < 0)
1112                 goto rename_error;
1113         key_put(key);
1114         _leave(" = 0");
1115         return 0;
1116
1117 rename_error:
1118         key_put(key);
1119 error:
1120         d_drop(new_dentry);
1121         _leave(" = %d", ret);
1122         return ret;
1123 }