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                       unsigned int flags);
  43
  44 const struct file_operations afs_dir_file_operations = {
  45         .open           = afs_dir_open,
  46         .release        = afs_release,
  47         .iterate_shared = afs_readdir,
  48         .lock           = afs_lock,
  49         .llseek         = generic_file_llseek,
  50 };
  51
  52 const struct inode_operations afs_dir_inode_operations = {
  53         .create         = afs_create,
  54         .lookup         = afs_lookup,
  55         .link           = afs_link,
  56         .unlink         = afs_unlink,
  57         .symlink        = afs_symlink,
  58         .mkdir          = afs_mkdir,
  59         .rmdir          = afs_rmdir,
  60         .rename         = afs_rename,
  61         .permission     = afs_permission,
  62         .getattr        = afs_getattr,
  63         .setattr        = afs_setattr,
  64         .listxattr      = afs_listxattr,
  65 };
  66
  67 const struct dentry_operations afs_fs_dentry_operations = {
  68         .d_revalidate   = afs_d_revalidate,
  69         .d_delete       = afs_d_delete,
  70         .d_release      = afs_d_release,
  71         .d_automount    = afs_d_automount,
  72 };
  73
  74 #define AFS_DIR_HASHTBL_SIZE    128
  75 #define AFS_DIR_DIRENT_SIZE     32
  76 #define AFS_DIRENT_PER_BLOCK    64
  77
  78 union afs_dirent {
  79         struct {
  80                 uint8_t         valid;
  81                 uint8_t         unused[1];
  82                 __be16          hash_next;
  83                 __be32          vnode;
  84                 __be32          unique;
  85                 uint8_t         name[16];
  86                 uint8_t         overflow[4];    /* if any char of the name (inc
  87                                                  * NUL) reaches here, consume
  88                                                  * the next dirent too */
  89         } u;
  90         uint8_t extended_name[32];
  91 };
  92
  93 /* AFS directory page header (one at the beginning of every 2048-byte chunk) */
  94 struct afs_dir_pagehdr {
  95         __be16          npages;
  96         __be16          magic;
  97 #define AFS_DIR_MAGIC htons(1234)
  98         uint8_t         nentries;
  99         uint8_t         bitmap[8];
 100         uint8_t         pad[19];
 101 };
 102
 103 /* directory block layout */
 104 union afs_dir_block {
 105
 106         struct afs_dir_pagehdr pagehdr;
 107
 108         struct {
 109                 struct afs_dir_pagehdr  pagehdr;
 110                 uint8_t                 alloc_ctrs[128];
 111                 /* dir hash table */
 112                 uint16_t                hashtable[AFS_DIR_HASHTBL_SIZE];
 113         } hdr;
 114
 115         union afs_dirent dirents[AFS_DIRENT_PER_BLOCK];
 116 };
 117
 118 /* layout on a linux VM page */
 119 struct afs_dir_page {
 120         union afs_dir_block blocks[PAGE_SIZE / sizeof(union afs_dir_block)];
 121 };
 122
 123 struct afs_lookup_cookie {
 124         struct dir_context ctx;
 125         struct afs_fid  fid;
 126         struct qstr name;
 127         int             found;
 128 };
 129
 130 /*
 131  * check that a directory page is valid
 132  */
 133 static inline bool afs_dir_check_page(struct inode *dir, struct page *page)
 134 {
 135         struct afs_dir_page *dbuf;
 136         loff_t latter;
 137         int tmp, qty;
 138
 139 #if 0
 140         /* check the page count */
 141         qty = desc.size / sizeof(dbuf->blocks[0]);
 142         if (qty == 0)
 143                 goto error;
 144
 145         if (page->index == 0 && qty != ntohs(dbuf->blocks[0].pagehdr.npages)) {
 146                 printk("kAFS: %s(%lu): wrong number of dir blocks %d!=%hu\n",
 147                        __func__, dir->i_ino, qty,
 148                        ntohs(dbuf->blocks[0].pagehdr.npages));
 149                 goto error;
 150         }
 151 #endif
 152
 153         /* determine how many magic numbers there should be in this page */
 154         latter = dir->i_size - page_offset(page);
 155         if (latter >= PAGE_SIZE)
 156                 qty = PAGE_SIZE;
 157         else
 158                 qty = latter;
 159         qty /= sizeof(union afs_dir_block);
 160
 161         /* check them */
 162         dbuf = page_address(page);
 163         for (tmp = 0; tmp < qty; tmp++) {
 164                 if (dbuf->blocks[tmp].pagehdr.magic != AFS_DIR_MAGIC) {
 165                         printk("kAFS: %s(%lu): bad magic %d/%d is %04hx\n",
 166                                __func__, dir->i_ino, tmp, qty,
 167                                ntohs(dbuf->blocks[tmp].pagehdr.magic));
 168                         goto error;
 169                 }
 170         }
 171
 172         SetPageChecked(page);
 173         return true;
 174
 175 error:
 176         SetPageError(page);
 177         return false;
 178 }
 179
 180 /*
 181  * discard a page cached in the pagecache
 182  */
 183 static inline void afs_dir_put_page(struct page *page)
 184 {
 185         kunmap(page);
 186         put_page(page);
 187 }
 188
 189 /*
 190  * get a page into the pagecache
 191  */
 192 static struct page *afs_dir_get_page(struct inode *dir, unsigned long index,
 193                                      struct key *key)
 194 {
 195         struct page *page;
 196         _enter("{%lu},%lu", dir->i_ino, index);
 197
 198         page = read_cache_page(dir->i_mapping, index, afs_page_filler, key);
 199         if (!IS_ERR(page)) {
 200                 kmap(page);
 201                 if (unlikely(!PageChecked(page))) {
 202                         if (PageError(page) || !afs_dir_check_page(dir, page))
 203                                 goto fail;
 204                 }
 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(struct dir_context *ctx,
 234                                  union afs_dir_block *block,
 235                                  unsigned blkoff)
 236 {
 237         union afs_dirent *dire;
 238         unsigned offset, next, curr;
 239         size_t nlen;
 240         int tmp;
 241
 242         _enter("%u,%x,%p,,",(unsigned)ctx->pos,blkoff,block);
 243
 244         curr = (ctx->pos - blkoff) / sizeof(union afs_dirent);
 245
 246         /* walk through the block, an entry at a time */
 247         for (offset = AFS_DIRENT_PER_BLOCK - block->pagehdr.nentries;
 248              offset < AFS_DIRENT_PER_BLOCK;
 249              offset = next
 250              ) {
 251                 next = offset + 1;
 252
 253                 /* skip entries marked unused in the bitmap */
 254                 if (!(block->pagehdr.bitmap[offset / 8] &
 255                       (1 << (offset % 8)))) {
 256                         _debug("ENT[%zu.%u]: unused",
 257                                blkoff / sizeof(union afs_dir_block), offset);
 258                         if (offset >= curr)
 259                                 ctx->pos = blkoff +
 260                                         next * sizeof(union afs_dirent);
 261                         continue;
 262                 }
 263
 264                 /* got a valid entry */
 265                 dire = &block->dirents[offset];
 266                 nlen = strnlen(dire->u.name,
 267                                sizeof(*block) -
 268                                offset * sizeof(union afs_dirent));
 269
 270                 _debug("ENT[%zu.%u]: %s %zu \"%s\"",
 271                        blkoff / sizeof(union afs_dir_block), offset,
 272                        (offset < curr ? "skip" : "fill"),
 273                        nlen, dire->u.name);
 274
 275                 /* work out where the next possible entry is */
 276                 for (tmp = nlen; tmp > 15; tmp -= sizeof(union afs_dirent)) {
 277                         if (next >= AFS_DIRENT_PER_BLOCK) {
 278                                 _debug("ENT[%zu.%u]:"
 279                                        " %u travelled beyond end dir block"
 280                                        " (len %u/%zu)",
 281                                        blkoff / sizeof(union afs_dir_block),
 282                                        offset, next, tmp, nlen);
 283                                 return -EIO;
 284                         }
 285                         if (!(block->pagehdr.bitmap[next / 8] &
 286                               (1 << (next % 8)))) {
 287                                 _debug("ENT[%zu.%u]:"
 288                                        " %u unmarked extension (len %u/%zu)",
 289                                        blkoff / sizeof(union afs_dir_block),
 290                                        offset, next, tmp, nlen);
 291                                 return -EIO;
 292                         }
 293
 294                         _debug("ENT[%zu.%u]: ext %u/%zu",
 295                                blkoff / sizeof(union afs_dir_block),
 296                                next, tmp, nlen);
 297                         next++;
 298                 }
 299
 300                 /* skip if starts before the current position */
 301                 if (offset < curr)
 302                         continue;
 303
 304                 /* found the next entry */
 305                 if (!dir_emit(ctx, dire->u.name, nlen,
 306                               ntohl(dire->u.vnode),
 307                               ctx->actor == afs_lookup_filldir ?
 308                               ntohl(dire->u.unique) : DT_UNKNOWN)) {
 309                         _leave(" = 0 [full]");
 310                         return 0;
 311                 }
 312
 313                 ctx->pos = blkoff + next * sizeof(union afs_dirent);
 314         }
 315
 316         _leave(" = 1 [more]");
 317         return 1;
 318 }
 319
 320 /*
 321  * iterate through the data blob that lists the contents of an AFS directory
 322  */
 323 static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx,
 324                            struct key *key)
 325 {
 326         union afs_dir_block *dblock;
 327         struct afs_dir_page *dbuf;
 328         struct page *page;
 329         unsigned blkoff, limit;
 330         int ret;
 331
 332         _enter("{%lu},%u,,", dir->i_ino, (unsigned)ctx->pos);
 333
 334         if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(dir)->flags)) {
 335                 _leave(" = -ESTALE");
 336                 return -ESTALE;
 337         }
 338
 339         /* round the file position up to the next entry boundary */
 340         ctx->pos += sizeof(union afs_dirent) - 1;
 341         ctx->pos &= ~(sizeof(union afs_dirent) - 1);
 342
 343         /* walk through the blocks in sequence */
 344         ret = 0;
 345         while (ctx->pos < dir->i_size) {
 346                 blkoff = ctx->pos & ~(sizeof(union afs_dir_block) - 1);
 347
 348                 /* fetch the appropriate page from the directory */
 349                 page = afs_dir_get_page(dir, blkoff / PAGE_SIZE, key);
 350                 if (IS_ERR(page)) {
 351                         ret = PTR_ERR(page);
 352                         break;
 353                 }
 354
 355                 limit = blkoff & ~(PAGE_SIZE - 1);
 356
 357                 dbuf = page_address(page);
 358
 359                 /* deal with the individual blocks stashed on this page */
 360                 do {
 361                         dblock = &dbuf->blocks[(blkoff % PAGE_SIZE) /
 362                                                sizeof(union afs_dir_block)];
 363                         ret = afs_dir_iterate_block(ctx, dblock, blkoff);
 364                         if (ret != 1) {
 365                                 afs_dir_put_page(page);
 366                                 goto out;
 367                         }
 368
 369                         blkoff += sizeof(union afs_dir_block);
 370
 371                 } while (ctx->pos < dir->i_size && blkoff < limit);
 372
 373                 afs_dir_put_page(page);
 374                 ret = 0;
 375         }
 376
 377 out:
 378         _leave(" = %d", ret);
 379         return ret;
 380 }
 381
 382 /*
 383  * read an AFS directory
 384  */
 385 static int afs_readdir(struct file *file, struct dir_context *ctx)
 386 {
 387         return afs_dir_iterate(file_inode(file),
 388                               ctx, file->private_data);
 389 }
 390
 391 /*
 392  * search the directory for a name
 393  * - if afs_dir_iterate_block() spots this function, it'll pass the FID
 394  *   uniquifier through dtype
 395  */
 396 static int afs_lookup_filldir(struct dir_context *ctx, const char *name,
 397                               int nlen, loff_t fpos, u64 ino, unsigned dtype)
 398 {
 399         struct afs_lookup_cookie *cookie =
 400                 container_of(ctx, struct afs_lookup_cookie, ctx);
 401
 402         _enter("{%s,%u},%s,%u,,%llu,%u",
 403                cookie->name.name, cookie->name.len, name, nlen,
 404                (unsigned long long) ino, dtype);
 405
 406         /* insanity checks first */
 407         BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048);
 408         BUILD_BUG_ON(sizeof(union afs_dirent) != 32);
 409
 410         if (cookie->name.len != nlen ||
 411             memcmp(cookie->name.name, name, nlen) != 0) {
 412                 _leave(" = 0 [no]");
 413                 return 0;
 414         }
 415
 416         cookie->fid.vnode = ino;
 417         cookie->fid.unique = dtype;
 418         cookie->found = 1;
 419
 420         _leave(" = -1 [found]");
 421         return -1;
 422 }
 423
 424 /*
 425  * do a lookup in a directory
 426  * - just returns the FID the dentry name maps to if found
 427  */
 428 static int afs_do_lookup(struct inode *dir, struct dentry *dentry,
 429                          struct afs_fid *fid, struct key *key)
 430 {
 431         struct afs_super_info *as = dir->i_sb->s_fs_info;
 432         struct afs_lookup_cookie cookie = {
 433                 .ctx.actor = afs_lookup_filldir,
 434                 .name = dentry->d_name,
 435                 .fid.vid = as->volume->vid
 436         };
 437         int ret;
 438
 439         _enter("{%lu},%p{%pd},", dir->i_ino, dentry, dentry);
 440
 441         /* search the directory */
 442         ret = afs_dir_iterate(dir, &cookie.ctx, key);
 443         if (ret < 0) {
 444                 _leave(" = %d [iter]", ret);
 445                 return ret;
 446         }
 447
 448         ret = -ENOENT;
 449         if (!cookie.found) {
 450                 _leave(" = -ENOENT [not found]");
 451                 return -ENOENT;
 452         }
 453
 454         *fid = cookie.fid;
 455         _leave(" = 0 { vn=%u u=%u }", fid->vnode, fid->unique);
 456         return 0;
 457 }
 458
 459 /*
 460  * Try to auto mount the mountpoint with pseudo directory, if the autocell
 461  * operation is setted.
 462  */
 463 static struct inode *afs_try_auto_mntpt(
 464         int ret, struct dentry *dentry, struct inode *dir, struct key *key,
 465         struct afs_fid *fid)
 466 {
 467         const char *devname = dentry->d_name.name;
 468         struct afs_vnode *vnode = AFS_FS_I(dir);
 469         struct inode *inode;
 470
 471         _enter("%d, %p{%pd}, {%x:%u}, %p",
 472                ret, dentry, dentry, vnode->fid.vid, vnode->fid.vnode, key);
 473
 474         if (ret != -ENOENT ||
 475             !test_bit(AFS_VNODE_AUTOCELL, &vnode->flags))
 476                 goto out;
 477
 478         inode = afs_iget_autocell(dir, devname, strlen(devname), key);
 479         if (IS_ERR(inode)) {
 480                 ret = PTR_ERR(inode);
 481                 goto out;
 482         }
 483
 484         *fid = AFS_FS_I(inode)->fid;
 485         _leave("= %p", inode);
 486         return inode;
 487
 488 out:
 489         _leave("= %d", ret);
 490         return ERR_PTR(ret);
 491 }
 492
 493 /*
 494  * look up an entry in a directory
 495  */
 496 static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
 497                                  unsigned int flags)
 498 {
 499         struct afs_vnode *vnode;
 500         struct afs_fid fid;
 501         struct inode *inode;
 502         struct key *key;
 503         int ret;
 504
 505         vnode = AFS_FS_I(dir);
 506
 507         _enter("{%x:%u},%p{%pd},",
 508                vnode->fid.vid, vnode->fid.vnode, dentry, dentry);
 509
 510         ASSERTCMP(d_inode(dentry), ==, NULL);
 511
 512         if (dentry->d_name.len >= AFSNAMEMAX) {
 513                 _leave(" = -ENAMETOOLONG");
 514                 return ERR_PTR(-ENAMETOOLONG);
 515         }
 516
 517         if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
 518                 _leave(" = -ESTALE");
 519                 return ERR_PTR(-ESTALE);
 520         }
 521
 522         key = afs_request_key(vnode->volume->cell);
 523         if (IS_ERR(key)) {
 524                 _leave(" = %ld [key]", PTR_ERR(key));
 525                 return ERR_CAST(key);
 526         }
 527
 528         ret = afs_validate(vnode, key);
 529         if (ret < 0) {
 530                 key_put(key);
 531                 _leave(" = %d [val]", ret);
 532                 return ERR_PTR(ret);
 533         }
 534
 535         ret = afs_do_lookup(dir, dentry, &fid, key);
 536         if (ret < 0) {
 537                 inode = afs_try_auto_mntpt(ret, dentry, dir, key, &fid);
 538                 if (!IS_ERR(inode)) {
 539                         key_put(key);
 540                         goto success;
 541                 }
 542
 543                 ret = PTR_ERR(inode);
 544                 key_put(key);
 545                 if (ret == -ENOENT) {
 546                         d_add(dentry, NULL);
 547                         _leave(" = NULL [negative]");
 548                         return NULL;
 549                 }
 550                 _leave(" = %d [do]", ret);
 551                 return ERR_PTR(ret);
 552         }
 553         dentry->d_fsdata = (void *)(unsigned long) vnode->status.data_version;
 554
 555         /* instantiate the dentry */
 556         inode = afs_iget(dir->i_sb, key, &fid, NULL, NULL);
 557         key_put(key);
 558         if (IS_ERR(inode)) {
 559                 _leave(" = %ld", PTR_ERR(inode));
 560                 return ERR_CAST(inode);
 561         }
 562
 563 success:
 564         d_add(dentry, inode);
 565         _leave(" = 0 { vn=%u u=%u } -> { ino=%lu v=%u }",
 566                fid.vnode,
 567                fid.unique,
 568                d_inode(dentry)->i_ino,
 569                d_inode(dentry)->i_generation);
 570
 571         return NULL;
 572 }
 573
 574 /*
 575  * check that a dentry lookup hit has found a valid entry
 576  * - NOTE! the hit can be a negative hit too, so we can't assume we have an
 577  *   inode
 578  */
 579 static int afs_d_revalidate(struct dentry *dentry, unsigned int flags)
 580 {
 581         struct afs_vnode *vnode, *dir;
 582         struct afs_fid uninitialized_var(fid);
 583         struct dentry *parent;
 584         struct key *key;
 585         void *dir_version;
 586         int ret;
 587
 588         if (flags & LOOKUP_RCU)
 589                 return -ECHILD;
 590
 591         vnode = AFS_FS_I(d_inode(dentry));
 592
 593         if (d_really_is_positive(dentry))
 594                 _enter("{v={%x:%u} n=%pd fl=%lx},",
 595                        vnode->fid.vid, vnode->fid.vnode, dentry,
 596                        vnode->flags);
 597         else
 598                 _enter("{neg n=%pd}", dentry);
 599
 600         key = afs_request_key(AFS_FS_S(dentry->d_sb)->volume->cell);
 601         if (IS_ERR(key))
 602                 key = NULL;
 603
 604         /* lock down the parent dentry so we can peer at it */
 605         parent = dget_parent(dentry);
 606         dir = AFS_FS_I(d_inode(parent));
 607
 608         /* validate the parent directory */
 609         if (test_bit(AFS_VNODE_MODIFIED, &dir->flags))
 610                 afs_validate(dir, key);
 611
 612         if (test_bit(AFS_VNODE_DELETED, &dir->flags)) {
 613                 _debug("%pd: parent dir deleted", dentry);
 614                 goto out_bad;
 615         }
 616
 617         dir_version = (void *) (unsigned long) dir->status.data_version;
 618         if (dentry->d_fsdata == dir_version)
 619                 goto out_valid; /* the dir contents are unchanged */
 620
 621         _debug("dir modified");
 622
 623         /* search the directory for this vnode */
 624         ret = afs_do_lookup(&dir->vfs_inode, dentry, &fid, key);
 625         switch (ret) {
 626         case 0:
 627                 /* the filename maps to something */
 628                 if (d_really_is_negative(dentry))
 629                         goto out_bad;
 630                 if (is_bad_inode(d_inode(dentry))) {
 631                         printk("kAFS: afs_d_revalidate: %pd2 has bad inode\n",
 632                                dentry);
 633                         goto out_bad;
 634                 }
 635
 636                 /* if the vnode ID has changed, then the dirent points to a
 637                  * different file */
 638                 if (fid.vnode != vnode->fid.vnode) {
 639                         _debug("%pd: dirent changed [%u != %u]",
 640                                dentry, fid.vnode,
 641                                vnode->fid.vnode);
 642                         goto not_found;
 643                 }
 644
 645                 /* if the vnode ID uniqifier has changed, then the file has
 646                  * been deleted and replaced, and the original vnode ID has
 647                  * been reused */
 648                 if (fid.unique != vnode->fid.unique) {
 649                         _debug("%pd: file deleted (uq %u -> %u I:%u)",
 650                                dentry, fid.unique,
 651                                vnode->fid.unique,
 652                                d_inode(dentry)->i_generation);
 653                         spin_lock(&vnode->lock);
 654                         set_bit(AFS_VNODE_DELETED, &vnode->flags);
 655                         spin_unlock(&vnode->lock);
 656                         goto not_found;
 657                 }
 658                 goto out_valid;
 659
 660         case -ENOENT:
 661                 /* the filename is unknown */
 662                 _debug("%pd: dirent not found", dentry);
 663                 if (d_really_is_positive(dentry))
 664                         goto not_found;
 665                 goto out_valid;
 666
 667         default:
 668                 _debug("failed to iterate dir %pd: %d",
 669                        parent, ret);
 670                 goto out_bad;
 671         }
 672
 673 out_valid:
 674         dentry->d_fsdata = dir_version;
 675         dput(parent);
 676         key_put(key);
 677         _leave(" = 1 [valid]");
 678         return 1;
 679
 680         /* the dirent, if it exists, now points to a different vnode */
 681 not_found:
 682         spin_lock(&dentry->d_lock);
 683         dentry->d_flags |= DCACHE_NFSFS_RENAMED;
 684         spin_unlock(&dentry->d_lock);
 685
 686 out_bad:
 687         _debug("dropping dentry %pd2", dentry);
 688         dput(parent);
 689         key_put(key);
 690
 691         _leave(" = 0 [bad]");
 692         return 0;
 693 }
 694
 695 /*
 696  * allow the VFS to enquire as to whether a dentry should be unhashed (mustn't
 697  * sleep)
 698  * - called from dput() when d_count is going to 0.
 699  * - return 1 to request dentry be unhashed, 0 otherwise
 700  */
 701 static int afs_d_delete(const struct dentry *dentry)
 702 {
 703         _enter("%pd", dentry);
 704
 705         if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
 706                 goto zap;
 707
 708         if (d_really_is_positive(dentry) &&
 709             (test_bit(AFS_VNODE_DELETED,   &AFS_FS_I(d_inode(dentry))->flags) ||
 710              test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(d_inode(dentry))->flags)))
 711                 goto zap;
 712
 713         _leave(" = 0 [keep]");
 714         return 0;
 715
 716 zap:
 717         _leave(" = 1 [zap]");
 718         return 1;
 719 }
 720
 721 /*
 722  * handle dentry release
 723  */
 724 static void afs_d_release(struct dentry *dentry)
 725 {
 726         _enter("%pd", dentry);
 727 }
 728
 729 /*
 730  * create a directory on an AFS filesystem
 731  */
 732 static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 733 {
 734         struct afs_file_status status;
 735         struct afs_callback cb;
 736         struct afs_server *server;
 737         struct afs_vnode *dvnode, *vnode;
 738         struct afs_fid fid;
 739         struct inode *inode;
 740         struct key *key;
 741         int ret;
 742
 743         dvnode = AFS_FS_I(dir);
 744
 745         _enter("{%x:%u},{%pd},%ho",
 746                dvnode->fid.vid, dvnode->fid.vnode, dentry, mode);
 747
 748         key = afs_request_key(dvnode->volume->cell);
 749         if (IS_ERR(key)) {
 750                 ret = PTR_ERR(key);
 751                 goto error;
 752         }
 753
 754         mode |= S_IFDIR;
 755         ret = afs_vnode_create(dvnode, key, dentry->d_name.name,
 756                                mode, &fid, &status, &cb, &server);
 757         if (ret < 0)
 758                 goto mkdir_error;
 759
 760         inode = afs_iget(dir->i_sb, key, &fid, &status, &cb);
 761         if (IS_ERR(inode)) {
 762                 /* ENOMEM at a really inconvenient time - just abandon the new
 763                  * directory on the server */
 764                 ret = PTR_ERR(inode);
 765                 goto iget_error;
 766         }
 767
 768         /* apply the status report we've got for the new vnode */
 769         vnode = AFS_FS_I(inode);
 770         spin_lock(&vnode->lock);
 771         vnode->update_cnt++;
 772         spin_unlock(&vnode->lock);
 773         afs_vnode_finalise_status_update(vnode, server);
 774         afs_put_server(server);
 775
 776         d_instantiate(dentry, inode);
 777         if (d_unhashed(dentry)) {
 778                 _debug("not hashed");
 779                 d_rehash(dentry);
 780         }
 781         key_put(key);
 782         _leave(" = 0");
 783         return 0;
 784
 785 iget_error:
 786         afs_put_server(server);
 787 mkdir_error:
 788         key_put(key);
 789 error:
 790         d_drop(dentry);
 791         _leave(" = %d", ret);
 792         return ret;
 793 }
 794
 795 /*
 796  * remove a directory from an AFS filesystem
 797  */
 798 static int afs_rmdir(struct inode *dir, struct dentry *dentry)
 799 {
 800         struct afs_vnode *dvnode, *vnode;
 801         struct key *key;
 802         int ret;
 803
 804         dvnode = AFS_FS_I(dir);
 805
 806         _enter("{%x:%u},{%pd}",
 807                dvnode->fid.vid, dvnode->fid.vnode, dentry);
 808
 809         key = afs_request_key(dvnode->volume->cell);
 810         if (IS_ERR(key)) {
 811                 ret = PTR_ERR(key);
 812                 goto error;
 813         }
 814
 815         ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, true);
 816         if (ret < 0)
 817                 goto rmdir_error;
 818
 819         if (d_really_is_positive(dentry)) {
 820                 vnode = AFS_FS_I(d_inode(dentry));
 821                 clear_nlink(&vnode->vfs_inode);
 822                 set_bit(AFS_VNODE_DELETED, &vnode->flags);
 823                 afs_discard_callback_on_delete(vnode);
 824         }
 825
 826         key_put(key);
 827         _leave(" = 0");
 828         return 0;
 829
 830 rmdir_error:
 831         key_put(key);
 832 error:
 833         _leave(" = %d", ret);
 834         return ret;
 835 }
 836
 837 /*
 838  * remove a file from an AFS filesystem
 839  */
 840 static int afs_unlink(struct inode *dir, struct dentry *dentry)
 841 {
 842         struct afs_vnode *dvnode, *vnode;
 843         struct key *key;
 844         int ret;
 845
 846         dvnode = AFS_FS_I(dir);
 847
 848         _enter("{%x:%u},{%pd}",
 849                dvnode->fid.vid, dvnode->fid.vnode, dentry);
 850
 851         ret = -ENAMETOOLONG;
 852         if (dentry->d_name.len >= AFSNAMEMAX)
 853                 goto error;
 854
 855         key = afs_request_key(dvnode->volume->cell);
 856         if (IS_ERR(key)) {
 857                 ret = PTR_ERR(key);
 858                 goto error;
 859         }
 860
 861         if (d_really_is_positive(dentry)) {
 862                 vnode = AFS_FS_I(d_inode(dentry));
 863
 864                 /* make sure we have a callback promise on the victim */
 865                 ret = afs_validate(vnode, key);
 866                 if (ret < 0)
 867                         goto error;
 868         }
 869
 870         ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, false);
 871         if (ret < 0)
 872                 goto remove_error;
 873
 874         if (d_really_is_positive(dentry)) {
 875                 /* if the file wasn't deleted due to excess hard links, the
 876                  * fileserver will break the callback promise on the file - if
 877                  * it had one - before it returns to us, and if it was deleted,
 878                  * it won't
 879                  *
 880                  * however, if we didn't have a callback promise outstanding,
 881                  * or it was outstanding on a different server, then it won't
 882                  * break it either...
 883                  */
 884                 vnode = AFS_FS_I(d_inode(dentry));
 885                 if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
 886                         _debug("AFS_VNODE_DELETED");
 887                 if (test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags))
 888                         _debug("AFS_VNODE_CB_BROKEN");
 889                 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
 890                 ret = afs_validate(vnode, key);
 891                 _debug("nlink %d [val %d]", vnode->vfs_inode.i_nlink, ret);
 892         }
 893
 894         key_put(key);
 895         _leave(" = 0");
 896         return 0;
 897
 898 remove_error:
 899         key_put(key);
 900 error:
 901         _leave(" = %d", ret);
 902         return ret;
 903 }
 904
 905 /*
 906  * create a regular file on an AFS filesystem
 907  */
 908 static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 909                       bool excl)
 910 {
 911         struct afs_file_status status;
 912         struct afs_callback cb;
 913         struct afs_server *server;
 914         struct afs_vnode *dvnode, *vnode;
 915         struct afs_fid fid;
 916         struct inode *inode;
 917         struct key *key;
 918         int ret;
 919
 920         dvnode = AFS_FS_I(dir);
 921
 922         _enter("{%x:%u},{%pd},%ho,",
 923                dvnode->fid.vid, dvnode->fid.vnode, dentry, mode);
 924
 925         key = afs_request_key(dvnode->volume->cell);
 926         if (IS_ERR(key)) {
 927                 ret = PTR_ERR(key);
 928                 goto error;
 929         }
 930
 931         mode |= S_IFREG;
 932         ret = afs_vnode_create(dvnode, key, dentry->d_name.name,
 933                                mode, &fid, &status, &cb, &server);
 934         if (ret < 0)
 935                 goto create_error;
 936
 937         inode = afs_iget(dir->i_sb, key, &fid, &status, &cb);
 938         if (IS_ERR(inode)) {
 939                 /* ENOMEM at a really inconvenient time - just abandon the new
 940                  * directory on the server */
 941                 ret = PTR_ERR(inode);
 942                 goto iget_error;
 943         }
 944
 945         /* apply the status report we've got for the new vnode */
 946         vnode = AFS_FS_I(inode);
 947         spin_lock(&vnode->lock);
 948         vnode->update_cnt++;
 949         spin_unlock(&vnode->lock);
 950         afs_vnode_finalise_status_update(vnode, server);
 951         afs_put_server(server);
 952
 953         d_instantiate(dentry, inode);
 954         if (d_unhashed(dentry)) {
 955                 _debug("not hashed");
 956                 d_rehash(dentry);
 957         }
 958         key_put(key);
 959         _leave(" = 0");
 960         return 0;
 961
 962 iget_error:
 963         afs_put_server(server);
 964 create_error:
 965         key_put(key);
 966 error:
 967         d_drop(dentry);
 968         _leave(" = %d", ret);
 969         return ret;
 970 }
 971
 972 /*
 973  * create a hard link between files in an AFS filesystem
 974  */
 975 static int afs_link(struct dentry *from, struct inode *dir,
 976                     struct dentry *dentry)
 977 {
 978         struct afs_vnode *dvnode, *vnode;
 979         struct key *key;
 980         int ret;
 981
 982         vnode = AFS_FS_I(d_inode(from));
 983         dvnode = AFS_FS_I(dir);
 984
 985         _enter("{%x:%u},{%x:%u},{%pd}",
 986                vnode->fid.vid, vnode->fid.vnode,
 987                dvnode->fid.vid, dvnode->fid.vnode,
 988                dentry);
 989
 990         key = afs_request_key(dvnode->volume->cell);
 991         if (IS_ERR(key)) {
 992                 ret = PTR_ERR(key);
 993                 goto error;
 994         }
 995
 996         ret = afs_vnode_link(dvnode, vnode, key, dentry->d_name.name);
 997         if (ret < 0)
 998                 goto link_error;
 999
1000         ihold(&vnode->vfs_inode);
1001         d_instantiate(dentry, &vnode->vfs_inode);
1002         key_put(key);
1003         _leave(" = 0");
1004         return 0;
1005
1006 link_error:
1007         key_put(key);
1008 error:
1009         d_drop(dentry);
1010         _leave(" = %d", ret);
1011         return ret;
1012 }
1013
1014 /*
1015  * create a symlink in an AFS filesystem
1016  */
1017 static int afs_symlink(struct inode *dir, struct dentry *dentry,
1018                        const char *content)
1019 {
1020         struct afs_file_status status;
1021         struct afs_server *server;
1022         struct afs_vnode *dvnode, *vnode;
1023         struct afs_fid fid;
1024         struct inode *inode;
1025         struct key *key;
1026         int ret;
1027
1028         dvnode = AFS_FS_I(dir);
1029
1030         _enter("{%x:%u},{%pd},%s",
1031                dvnode->fid.vid, dvnode->fid.vnode, dentry,
1032                content);
1033
1034         ret = -EINVAL;
1035         if (strlen(content) >= AFSPATHMAX)
1036                 goto error;
1037
1038         key = afs_request_key(dvnode->volume->cell);
1039         if (IS_ERR(key)) {
1040                 ret = PTR_ERR(key);
1041                 goto error;
1042         }
1043
1044         ret = afs_vnode_symlink(dvnode, key, dentry->d_name.name, content,
1045                                 &fid, &status, &server);
1046         if (ret < 0)
1047                 goto create_error;
1048
1049         inode = afs_iget(dir->i_sb, key, &fid, &status, NULL);
1050         if (IS_ERR(inode)) {
1051                 /* ENOMEM at a really inconvenient time - just abandon the new
1052                  * directory on the server */
1053                 ret = PTR_ERR(inode);
1054                 goto iget_error;
1055         }
1056
1057         /* apply the status report we've got for the new vnode */
1058         vnode = AFS_FS_I(inode);
1059         spin_lock(&vnode->lock);
1060         vnode->update_cnt++;
1061         spin_unlock(&vnode->lock);
1062         afs_vnode_finalise_status_update(vnode, server);
1063         afs_put_server(server);
1064
1065         d_instantiate(dentry, inode);
1066         if (d_unhashed(dentry)) {
1067                 _debug("not hashed");
1068                 d_rehash(dentry);
1069         }
1070         key_put(key);
1071         _leave(" = 0");
1072         return 0;
1073
1074 iget_error:
1075         afs_put_server(server);
1076 create_error:
1077         key_put(key);
1078 error:
1079         d_drop(dentry);
1080         _leave(" = %d", ret);
1081         return ret;
1082 }
1083
1084 /*
1085  * rename a file in an AFS filesystem and/or move it between directories
1086  */
1087 static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
1088                       struct inode *new_dir, struct dentry *new_dentry,
1089                       unsigned int flags)
1090 {
1091         struct afs_vnode *orig_dvnode, *new_dvnode, *vnode;
1092         struct key *key;
1093         int ret;
1094
1095         if (flags)
1096                 return -EINVAL;
1097
1098         vnode = AFS_FS_I(d_inode(old_dentry));
1099         orig_dvnode = AFS_FS_I(old_dir);
1100         new_dvnode = AFS_FS_I(new_dir);
1101
1102         _enter("{%x:%u},{%x:%u},{%x:%u},{%pd}",
1103                orig_dvnode->fid.vid, orig_dvnode->fid.vnode,
1104                vnode->fid.vid, vnode->fid.vnode,
1105                new_dvnode->fid.vid, new_dvnode->fid.vnode,
1106                new_dentry);
1107
1108         key = afs_request_key(orig_dvnode->volume->cell);
1109         if (IS_ERR(key)) {
1110                 ret = PTR_ERR(key);
1111                 goto error;
1112         }
1113
1114         ret = afs_vnode_rename(orig_dvnode, new_dvnode, key,
1115                                old_dentry->d_name.name,
1116                                new_dentry->d_name.name);
1117         if (ret < 0)
1118                 goto rename_error;
1119         key_put(key);
1120         _leave(" = 0");
1121         return 0;
1122
1123 rename_error:
1124         key_put(key);
1125 error:
1126         d_drop(new_dentry);
1127         _leave(" = %d", ret);
1128         return ret;
1129 }