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 };
  65
  66 const struct dentry_operations afs_fs_dentry_operations = {
  67         .d_revalidate   = afs_d_revalidate,
  68         .d_delete       = afs_d_delete,
  69         .d_release      = afs_d_release,
  70         .d_automount    = afs_d_automount,
  71 };
  72
  73 #define AFS_DIR_HASHTBL_SIZE    128
  74 #define AFS_DIR_DIRENT_SIZE     32
  75 #define AFS_DIRENT_PER_BLOCK    64
  76
  77 union afs_dirent {
  78         struct {
  79                 uint8_t         valid;
  80                 uint8_t         unused[1];
  81                 __be16          hash_next;
  82                 __be32          vnode;
  83                 __be32          unique;
  84                 uint8_t         name[16];
  85                 uint8_t         overflow[4];    /* if any char of the name (inc
  86                                                  * NUL) reaches here, consume
  87                                                  * the next dirent too */
  88         } u;
  89         uint8_t extended_name[32];
  90 };
  91
  92 /* AFS directory page header (one at the beginning of every 2048-byte chunk) */
  93 struct afs_dir_pagehdr {
  94         __be16          npages;
  95         __be16          magic;
  96 #define AFS_DIR_MAGIC htons(1234)
  97         uint8_t         nentries;
  98         uint8_t         bitmap[8];
  99         uint8_t         pad[19];
 100 };
 101
 102 /* directory block layout */
 103 union afs_dir_block {
 104
 105         struct afs_dir_pagehdr pagehdr;
 106
 107         struct {
 108                 struct afs_dir_pagehdr  pagehdr;
 109                 uint8_t                 alloc_ctrs[128];
 110                 /* dir hash table */
 111                 uint16_t                hashtable[AFS_DIR_HASHTBL_SIZE];
 112         } hdr;
 113
 114         union afs_dirent dirents[AFS_DIRENT_PER_BLOCK];
 115 };
 116
 117 /* layout on a linux VM page */
 118 struct afs_dir_page {
 119         union afs_dir_block blocks[PAGE_SIZE / sizeof(union afs_dir_block)];
 120 };
 121
 122 struct afs_lookup_cookie {
 123         struct dir_context ctx;
 124         struct afs_fid  fid;
 125         struct qstr name;
 126         int             found;
 127 };
 128
 129 /*
 130  * check that a directory page is valid
 131  */
 132 static inline bool afs_dir_check_page(struct inode *dir, struct page *page)
 133 {
 134         struct afs_dir_page *dbuf;
 135         loff_t latter;
 136         int tmp, qty;
 137
 138 #if 0
 139         /* check the page count */
 140         qty = desc.size / sizeof(dbuf->blocks[0]);
 141         if (qty == 0)
 142                 goto error;
 143
 144         if (page->index == 0 && qty != ntohs(dbuf->blocks[0].pagehdr.npages)) {
 145                 printk("kAFS: %s(%lu): wrong number of dir blocks %d!=%hu\n",
 146                        __func__, dir->i_ino, qty,
 147                        ntohs(dbuf->blocks[0].pagehdr.npages));
 148                 goto error;
 149         }
 150 #endif
 151
 152         /* determine how many magic numbers there should be in this page */
 153         latter = dir->i_size - page_offset(page);
 154         if (latter >= PAGE_SIZE)
 155                 qty = PAGE_SIZE;
 156         else
 157                 qty = latter;
 158         qty /= sizeof(union afs_dir_block);
 159
 160         /* check them */
 161         dbuf = page_address(page);
 162         for (tmp = 0; tmp < qty; tmp++) {
 163                 if (dbuf->blocks[tmp].pagehdr.magic != AFS_DIR_MAGIC) {
 164                         printk("kAFS: %s(%lu): bad magic %d/%d is %04hx\n",
 165                                __func__, dir->i_ino, tmp, qty,
 166                                ntohs(dbuf->blocks[tmp].pagehdr.magic));
 167                         goto error;
 168                 }
 169         }
 170
 171         SetPageChecked(page);
 172         return true;
 173
 174 error:
 175         SetPageError(page);
 176         return false;
 177 }
 178
 179 /*
 180  * discard a page cached in the pagecache
 181  */
 182 static inline void afs_dir_put_page(struct page *page)
 183 {
 184         kunmap(page);
 185         put_page(page);
 186 }
 187
 188 /*
 189  * get a page into the pagecache
 190  */
 191 static struct page *afs_dir_get_page(struct inode *dir, unsigned long index,
 192                                      struct key *key)
 193 {
 194         struct page *page;
 195         _enter("{%lu},%lu", dir->i_ino, index);
 196
 197         page = read_cache_page(dir->i_mapping, index, afs_page_filler, key);
 198         if (!IS_ERR(page)) {
 199                 kmap(page);
 200                 if (unlikely(!PageChecked(page))) {
 201                         if (PageError(page) || !afs_dir_check_page(dir, page))
 202                                 goto fail;
 203                 }
 204         }
 205         return page;
 206
 207 fail:
 208         afs_dir_put_page(page);
 209         _leave(" = -EIO");
 210         return ERR_PTR(-EIO);
 211 }
 212
 213 /*
 214  * open an AFS directory file
 215  */
 216 static int afs_dir_open(struct inode *inode, struct file *file)
 217 {
 218         _enter("{%lu}", inode->i_ino);
 219
 220         BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048);
 221         BUILD_BUG_ON(sizeof(union afs_dirent) != 32);
 222
 223         if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(inode)->flags))
 224                 return -ENOENT;
 225
 226         return afs_open(inode, file);
 227 }
 228
 229 /*
 230  * deal with one block in an AFS directory
 231  */
 232 static int afs_dir_iterate_block(struct dir_context *ctx,
 233                                  union afs_dir_block *block,
 234                                  unsigned blkoff)
 235 {
 236         union afs_dirent *dire;
 237         unsigned offset, next, curr;
 238         size_t nlen;
 239         int tmp;
 240
 241         _enter("%u,%x,%p,,",(unsigned)ctx->pos,blkoff,block);
 242
 243         curr = (ctx->pos - blkoff) / sizeof(union afs_dirent);
 244
 245         /* walk through the block, an entry at a time */
 246         for (offset = AFS_DIRENT_PER_BLOCK - block->pagehdr.nentries;
 247              offset < AFS_DIRENT_PER_BLOCK;
 248              offset = next
 249              ) {
 250                 next = offset + 1;
 251
 252                 /* skip entries marked unused in the bitmap */
 253                 if (!(block->pagehdr.bitmap[offset / 8] &
 254                       (1 << (offset % 8)))) {
 255                         _debug("ENT[%zu.%u]: unused",
 256                                blkoff / sizeof(union afs_dir_block), offset);
 257                         if (offset >= curr)
 258                                 ctx->pos = blkoff +
 259                                         next * sizeof(union afs_dirent);
 260                         continue;
 261                 }
 262
 263                 /* got a valid entry */
 264                 dire = &block->dirents[offset];
 265                 nlen = strnlen(dire->u.name,
 266                                sizeof(*block) -
 267                                offset * sizeof(union afs_dirent));
 268
 269                 _debug("ENT[%zu.%u]: %s %zu \"%s\"",
 270                        blkoff / sizeof(union afs_dir_block), offset,
 271                        (offset < curr ? "skip" : "fill"),
 272                        nlen, dire->u.name);
 273
 274                 /* work out where the next possible entry is */
 275                 for (tmp = nlen; tmp > 15; tmp -= sizeof(union afs_dirent)) {
 276                         if (next >= AFS_DIRENT_PER_BLOCK) {
 277                                 _debug("ENT[%zu.%u]:"
 278                                        " %u travelled beyond end dir block"
 279                                        " (len %u/%zu)",
 280                                        blkoff / sizeof(union afs_dir_block),
 281                                        offset, next, tmp, nlen);
 282                                 return -EIO;
 283                         }
 284                         if (!(block->pagehdr.bitmap[next / 8] &
 285                               (1 << (next % 8)))) {
 286                                 _debug("ENT[%zu.%u]:"
 287                                        " %u unmarked extension (len %u/%zu)",
 288                                        blkoff / sizeof(union afs_dir_block),
 289                                        offset, next, tmp, nlen);
 290                                 return -EIO;
 291                         }
 292
 293                         _debug("ENT[%zu.%u]: ext %u/%zu",
 294                                blkoff / sizeof(union afs_dir_block),
 295                                next, tmp, nlen);
 296                         next++;
 297                 }
 298
 299                 /* skip if starts before the current position */
 300                 if (offset < curr)
 301                         continue;
 302
 303                 /* found the next entry */
 304                 if (!dir_emit(ctx, dire->u.name, nlen,
 305                               ntohl(dire->u.vnode),
 306                               ctx->actor == afs_lookup_filldir ?
 307                               ntohl(dire->u.unique) : DT_UNKNOWN)) {
 308                         _leave(" = 0 [full]");
 309                         return 0;
 310                 }
 311
 312                 ctx->pos = blkoff + next * sizeof(union afs_dirent);
 313         }
 314
 315         _leave(" = 1 [more]");
 316         return 1;
 317 }
 318
 319 /*
 320  * iterate through the data blob that lists the contents of an AFS directory
 321  */
 322 static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx,
 323                            struct key *key)
 324 {
 325         union afs_dir_block *dblock;
 326         struct afs_dir_page *dbuf;
 327         struct page *page;
 328         unsigned blkoff, limit;
 329         int ret;
 330
 331         _enter("{%lu},%u,,", dir->i_ino, (unsigned)ctx->pos);
 332
 333         if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(dir)->flags)) {
 334                 _leave(" = -ESTALE");
 335                 return -ESTALE;
 336         }
 337
 338         /* round the file position up to the next entry boundary */
 339         ctx->pos += sizeof(union afs_dirent) - 1;
 340         ctx->pos &= ~(sizeof(union afs_dirent) - 1);
 341
 342         /* walk through the blocks in sequence */
 343         ret = 0;
 344         while (ctx->pos < dir->i_size) {
 345                 blkoff = ctx->pos & ~(sizeof(union afs_dir_block) - 1);
 346
 347                 /* fetch the appropriate page from the directory */
 348                 page = afs_dir_get_page(dir, blkoff / PAGE_SIZE, key);
 349                 if (IS_ERR(page)) {
 350                         ret = PTR_ERR(page);
 351                         break;
 352                 }
 353
 354                 limit = blkoff & ~(PAGE_SIZE - 1);
 355
 356                 dbuf = page_address(page);
 357
 358                 /* deal with the individual blocks stashed on this page */
 359                 do {
 360                         dblock = &dbuf->blocks[(blkoff % PAGE_SIZE) /
 361                                                sizeof(union afs_dir_block)];
 362                         ret = afs_dir_iterate_block(ctx, dblock, blkoff);
 363                         if (ret != 1) {
 364                                 afs_dir_put_page(page);
 365                                 goto out;
 366                         }
 367
 368                         blkoff += sizeof(union afs_dir_block);
 369
 370                 } while (ctx->pos < dir->i_size && blkoff < limit);
 371
 372                 afs_dir_put_page(page);
 373                 ret = 0;
 374         }
 375
 376 out:
 377         _leave(" = %d", ret);
 378         return ret;
 379 }
 380
 381 /*
 382  * read an AFS directory
 383  */
 384 static int afs_readdir(struct file *file, struct dir_context *ctx)
 385 {
 386         return afs_dir_iterate(file_inode(file),
 387                               ctx, file->private_data);
 388 }
 389
 390 /*
 391  * search the directory for a name
 392  * - if afs_dir_iterate_block() spots this function, it'll pass the FID
 393  *   uniquifier through dtype
 394  */
 395 static int afs_lookup_filldir(struct dir_context *ctx, const char *name,
 396                               int nlen, loff_t fpos, u64 ino, unsigned dtype)
 397 {
 398         struct afs_lookup_cookie *cookie =
 399                 container_of(ctx, struct afs_lookup_cookie, ctx);
 400
 401         _enter("{%s,%u},%s,%u,,%llu,%u",
 402                cookie->name.name, cookie->name.len, name, nlen,
 403                (unsigned long long) ino, dtype);
 404
 405         /* insanity checks first */
 406         BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048);
 407         BUILD_BUG_ON(sizeof(union afs_dirent) != 32);
 408
 409         if (cookie->name.len != nlen ||
 410             memcmp(cookie->name.name, name, nlen) != 0) {
 411                 _leave(" = 0 [no]");
 412                 return 0;
 413         }
 414
 415         cookie->fid.vnode = ino;
 416         cookie->fid.unique = dtype;
 417         cookie->found = 1;
 418
 419         _leave(" = -1 [found]");
 420         return -1;
 421 }
 422
 423 /*
 424  * do a lookup in a directory
 425  * - just returns the FID the dentry name maps to if found
 426  */
 427 static int afs_do_lookup(struct inode *dir, struct dentry *dentry,
 428                          struct afs_fid *fid, struct key *key)
 429 {
 430         struct afs_super_info *as = dir->i_sb->s_fs_info;
 431         struct afs_lookup_cookie cookie = {
 432                 .ctx.actor = afs_lookup_filldir,
 433                 .name = dentry->d_name,
 434                 .fid.vid = as->volume->vid
 435         };
 436         int ret;
 437
 438         _enter("{%lu},%p{%pd},", dir->i_ino, dentry, dentry);
 439
 440         /* search the directory */
 441         ret = afs_dir_iterate(dir, &cookie.ctx, key);
 442         if (ret < 0) {
 443                 _leave(" = %d [iter]", ret);
 444                 return ret;
 445         }
 446
 447         ret = -ENOENT;
 448         if (!cookie.found) {
 449                 _leave(" = -ENOENT [not found]");
 450                 return -ENOENT;
 451         }
 452
 453         *fid = cookie.fid;
 454         _leave(" = 0 { vn=%u u=%u }", fid->vnode, fid->unique);
 455         return 0;
 456 }
 457
 458 /*
 459  * Try to auto mount the mountpoint with pseudo directory, if the autocell
 460  * operation is setted.
 461  */
 462 static struct inode *afs_try_auto_mntpt(
 463         int ret, struct dentry *dentry, struct inode *dir, struct key *key,
 464         struct afs_fid *fid)
 465 {
 466         const char *devname = dentry->d_name.name;
 467         struct afs_vnode *vnode = AFS_FS_I(dir);
 468         struct inode *inode;
 469
 470         _enter("%d, %p{%pd}, {%x:%u}, %p",
 471                ret, dentry, dentry, vnode->fid.vid, vnode->fid.vnode, key);
 472
 473         if (ret != -ENOENT ||
 474             !test_bit(AFS_VNODE_AUTOCELL, &vnode->flags))
 475                 goto out;
 476
 477         inode = afs_iget_autocell(dir, devname, strlen(devname), key);
 478         if (IS_ERR(inode)) {
 479                 ret = PTR_ERR(inode);
 480                 goto out;
 481         }
 482
 483         *fid = AFS_FS_I(inode)->fid;
 484         _leave("= %p", inode);
 485         return inode;
 486
 487 out:
 488         _leave("= %d", ret);
 489         return ERR_PTR(ret);
 490 }
 491
 492 /*
 493  * look up an entry in a directory
 494  */
 495 static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
 496                                  unsigned int flags)
 497 {
 498         struct afs_vnode *vnode;
 499         struct afs_fid fid;
 500         struct inode *inode;
 501         struct key *key;
 502         int ret;
 503
 504         vnode = AFS_FS_I(dir);
 505
 506         _enter("{%x:%u},%p{%pd},",
 507                vnode->fid.vid, vnode->fid.vnode, dentry, dentry);
 508
 509         ASSERTCMP(d_inode(dentry), ==, NULL);
 510
 511         if (dentry->d_name.len >= AFSNAMEMAX) {
 512                 _leave(" = -ENAMETOOLONG");
 513                 return ERR_PTR(-ENAMETOOLONG);
 514         }
 515
 516         if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
 517                 _leave(" = -ESTALE");
 518                 return ERR_PTR(-ESTALE);
 519         }
 520
 521         key = afs_request_key(vnode->volume->cell);
 522         if (IS_ERR(key)) {
 523                 _leave(" = %ld [key]", PTR_ERR(key));
 524                 return ERR_CAST(key);
 525         }
 526
 527         ret = afs_validate(vnode, key);
 528         if (ret < 0) {
 529                 key_put(key);
 530                 _leave(" = %d [val]", ret);
 531                 return ERR_PTR(ret);
 532         }
 533
 534         ret = afs_do_lookup(dir, dentry, &fid, key);
 535         if (ret < 0) {
 536                 inode = afs_try_auto_mntpt(ret, dentry, dir, key, &fid);
 537                 if (!IS_ERR(inode)) {
 538                         key_put(key);
 539                         goto success;
 540                 }
 541
 542                 ret = PTR_ERR(inode);
 543                 key_put(key);
 544                 if (ret == -ENOENT) {
 545                         d_add(dentry, NULL);
 546                         _leave(" = NULL [negative]");
 547                         return NULL;
 548                 }
 549                 _leave(" = %d [do]", ret);
 550                 return ERR_PTR(ret);
 551         }
 552         dentry->d_fsdata = (void *)(unsigned long) vnode->status.data_version;
 553
 554         /* instantiate the dentry */
 555         inode = afs_iget(dir->i_sb, key, &fid, NULL, NULL);
 556         key_put(key);
 557         if (IS_ERR(inode)) {
 558                 _leave(" = %ld", PTR_ERR(inode));
 559                 return ERR_CAST(inode);
 560         }
 561
 562 success:
 563         d_add(dentry, inode);
 564         _leave(" = 0 { vn=%u u=%u } -> { ino=%lu v=%u }",
 565                fid.vnode,
 566                fid.unique,
 567                d_inode(dentry)->i_ino,
 568                d_inode(dentry)->i_generation);
 569
 570         return NULL;
 571 }
 572
 573 /*
 574  * check that a dentry lookup hit has found a valid entry
 575  * - NOTE! the hit can be a negative hit too, so we can't assume we have an
 576  *   inode
 577  */
 578 static int afs_d_revalidate(struct dentry *dentry, unsigned int flags)
 579 {
 580         struct afs_vnode *vnode, *dir;
 581         struct afs_fid uninitialized_var(fid);
 582         struct dentry *parent;
 583         struct key *key;
 584         void *dir_version;
 585         int ret;
 586
 587         if (flags & LOOKUP_RCU)
 588                 return -ECHILD;
 589
 590         vnode = AFS_FS_I(d_inode(dentry));
 591
 592         if (d_really_is_positive(dentry))
 593                 _enter("{v={%x:%u} n=%pd fl=%lx},",
 594                        vnode->fid.vid, vnode->fid.vnode, dentry,
 595                        vnode->flags);
 596         else
 597                 _enter("{neg n=%pd}", dentry);
 598
 599         key = afs_request_key(AFS_FS_S(dentry->d_sb)->volume->cell);
 600         if (IS_ERR(key))
 601                 key = NULL;
 602
 603         /* lock down the parent dentry so we can peer at it */
 604         parent = dget_parent(dentry);
 605         dir = AFS_FS_I(d_inode(parent));
 606
 607         /* validate the parent directory */
 608         if (test_bit(AFS_VNODE_MODIFIED, &dir->flags))
 609                 afs_validate(dir, key);
 610
 611         if (test_bit(AFS_VNODE_DELETED, &dir->flags)) {
 612                 _debug("%pd: parent dir deleted", dentry);
 613                 goto out_bad;
 614         }
 615
 616         dir_version = (void *) (unsigned long) dir->status.data_version;
 617         if (dentry->d_fsdata == dir_version)
 618                 goto out_valid; /* the dir contents are unchanged */
 619
 620         _debug("dir modified");
 621
 622         /* search the directory for this vnode */
 623         ret = afs_do_lookup(&dir->vfs_inode, dentry, &fid, key);
 624         switch (ret) {
 625         case 0:
 626                 /* the filename maps to something */
 627                 if (d_really_is_negative(dentry))
 628                         goto out_bad;
 629                 if (is_bad_inode(d_inode(dentry))) {
 630                         printk("kAFS: afs_d_revalidate: %pd2 has bad inode\n",
 631                                dentry);
 632                         goto out_bad;
 633                 }
 634
 635                 /* if the vnode ID has changed, then the dirent points to a
 636                  * different file */
 637                 if (fid.vnode != vnode->fid.vnode) {
 638                         _debug("%pd: dirent changed [%u != %u]",
 639                                dentry, fid.vnode,
 640                                vnode->fid.vnode);
 641                         goto not_found;
 642                 }
 643
 644                 /* if the vnode ID uniqifier has changed, then the file has
 645                  * been deleted and replaced, and the original vnode ID has
 646                  * been reused */
 647                 if (fid.unique != vnode->fid.unique) {
 648                         _debug("%pd: file deleted (uq %u -> %u I:%u)",
 649                                dentry, fid.unique,
 650                                vnode->fid.unique,
 651                                d_inode(dentry)->i_generation);
 652                         spin_lock(&vnode->lock);
 653                         set_bit(AFS_VNODE_DELETED, &vnode->flags);
 654                         spin_unlock(&vnode->lock);
 655                         goto not_found;
 656                 }
 657                 goto out_valid;
 658
 659         case -ENOENT:
 660                 /* the filename is unknown */
 661                 _debug("%pd: dirent not found", dentry);
 662                 if (d_really_is_positive(dentry))
 663                         goto not_found;
 664                 goto out_valid;
 665
 666         default:
 667                 _debug("failed to iterate dir %pd: %d",
 668                        parent, ret);
 669                 goto out_bad;
 670         }
 671
 672 out_valid:
 673         dentry->d_fsdata = dir_version;
 674         dput(parent);
 675         key_put(key);
 676         _leave(" = 1 [valid]");
 677         return 1;
 678
 679         /* the dirent, if it exists, now points to a different vnode */
 680 not_found:
 681         spin_lock(&dentry->d_lock);
 682         dentry->d_flags |= DCACHE_NFSFS_RENAMED;
 683         spin_unlock(&dentry->d_lock);
 684
 685 out_bad:
 686         _debug("dropping dentry %pd2", dentry);
 687         dput(parent);
 688         key_put(key);
 689
 690         _leave(" = 0 [bad]");
 691         return 0;
 692 }
 693
 694 /*
 695  * allow the VFS to enquire as to whether a dentry should be unhashed (mustn't
 696  * sleep)
 697  * - called from dput() when d_count is going to 0.
 698  * - return 1 to request dentry be unhashed, 0 otherwise
 699  */
 700 static int afs_d_delete(const struct dentry *dentry)
 701 {
 702         _enter("%pd", dentry);
 703
 704         if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
 705                 goto zap;
 706
 707         if (d_really_is_positive(dentry) &&
 708             (test_bit(AFS_VNODE_DELETED,   &AFS_FS_I(d_inode(dentry))->flags) ||
 709              test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(d_inode(dentry))->flags)))
 710                 goto zap;
 711
 712         _leave(" = 0 [keep]");
 713         return 0;
 714
 715 zap:
 716         _leave(" = 1 [zap]");
 717         return 1;
 718 }
 719
 720 /*
 721  * handle dentry release
 722  */
 723 static void afs_d_release(struct dentry *dentry)
 724 {
 725         _enter("%pd", dentry);
 726 }
 727
 728 /*
 729  * create a directory on an AFS filesystem
 730  */
 731 static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 732 {
 733         struct afs_file_status status;
 734         struct afs_callback cb;
 735         struct afs_server *server;
 736         struct afs_vnode *dvnode, *vnode;
 737         struct afs_fid fid;
 738         struct inode *inode;
 739         struct key *key;
 740         int ret;
 741
 742         dvnode = AFS_FS_I(dir);
 743
 744         _enter("{%x:%u},{%pd},%ho",
 745                dvnode->fid.vid, dvnode->fid.vnode, dentry, mode);
 746
 747         key = afs_request_key(dvnode->volume->cell);
 748         if (IS_ERR(key)) {
 749                 ret = PTR_ERR(key);
 750                 goto error;
 751         }
 752
 753         mode |= S_IFDIR;
 754         ret = afs_vnode_create(dvnode, key, dentry->d_name.name,
 755                                mode, &fid, &status, &cb, &server);
 756         if (ret < 0)
 757                 goto mkdir_error;
 758
 759         inode = afs_iget(dir->i_sb, key, &fid, &status, &cb);
 760         if (IS_ERR(inode)) {
 761                 /* ENOMEM at a really inconvenient time - just abandon the new
 762                  * directory on the server */
 763                 ret = PTR_ERR(inode);
 764                 goto iget_error;
 765         }
 766
 767         /* apply the status report we've got for the new vnode */
 768         vnode = AFS_FS_I(inode);
 769         spin_lock(&vnode->lock);
 770         vnode->update_cnt++;
 771         spin_unlock(&vnode->lock);
 772         afs_vnode_finalise_status_update(vnode, server);
 773         afs_put_server(server);
 774
 775         d_instantiate(dentry, inode);
 776         if (d_unhashed(dentry)) {
 777                 _debug("not hashed");
 778                 d_rehash(dentry);
 779         }
 780         key_put(key);
 781         _leave(" = 0");
 782         return 0;
 783
 784 iget_error:
 785         afs_put_server(server);
 786 mkdir_error:
 787         key_put(key);
 788 error:
 789         d_drop(dentry);
 790         _leave(" = %d", ret);
 791         return ret;
 792 }
 793
 794 /*
 795  * remove a directory from an AFS filesystem
 796  */
 797 static int afs_rmdir(struct inode *dir, struct dentry *dentry)
 798 {
 799         struct afs_vnode *dvnode, *vnode;
 800         struct key *key;
 801         int ret;
 802
 803         dvnode = AFS_FS_I(dir);
 804
 805         _enter("{%x:%u},{%pd}",
 806                dvnode->fid.vid, dvnode->fid.vnode, dentry);
 807
 808         key = afs_request_key(dvnode->volume->cell);
 809         if (IS_ERR(key)) {
 810                 ret = PTR_ERR(key);
 811                 goto error;
 812         }
 813
 814         ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, true);
 815         if (ret < 0)
 816                 goto rmdir_error;
 817
 818         if (d_really_is_positive(dentry)) {
 819                 vnode = AFS_FS_I(d_inode(dentry));
 820                 clear_nlink(&vnode->vfs_inode);
 821                 set_bit(AFS_VNODE_DELETED, &vnode->flags);
 822                 afs_discard_callback_on_delete(vnode);
 823         }
 824
 825         key_put(key);
 826         _leave(" = 0");
 827         return 0;
 828
 829 rmdir_error:
 830         key_put(key);
 831 error:
 832         _leave(" = %d", ret);
 833         return ret;
 834 }
 835
 836 /*
 837  * remove a file from an AFS filesystem
 838  */
 839 static int afs_unlink(struct inode *dir, struct dentry *dentry)
 840 {
 841         struct afs_vnode *dvnode, *vnode;
 842         struct key *key;
 843         int ret;
 844
 845         dvnode = AFS_FS_I(dir);
 846
 847         _enter("{%x:%u},{%pd}",
 848                dvnode->fid.vid, dvnode->fid.vnode, dentry);
 849
 850         ret = -ENAMETOOLONG;
 851         if (dentry->d_name.len >= AFSNAMEMAX)
 852                 goto error;
 853
 854         key = afs_request_key(dvnode->volume->cell);
 855         if (IS_ERR(key)) {
 856                 ret = PTR_ERR(key);
 857                 goto error;
 858         }
 859
 860         if (d_really_is_positive(dentry)) {
 861                 vnode = AFS_FS_I(d_inode(dentry));
 862
 863                 /* make sure we have a callback promise on the victim */
 864                 ret = afs_validate(vnode, key);
 865                 if (ret < 0)
 866                         goto error;
 867         }
 868
 869         ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, false);
 870         if (ret < 0)
 871                 goto remove_error;
 872
 873         if (d_really_is_positive(dentry)) {
 874                 /* if the file wasn't deleted due to excess hard links, the
 875                  * fileserver will break the callback promise on the file - if
 876                  * it had one - before it returns to us, and if it was deleted,
 877                  * it won't
 878                  *
 879                  * however, if we didn't have a callback promise outstanding,
 880                  * or it was outstanding on a different server, then it won't
 881                  * break it either...
 882                  */
 883                 vnode = AFS_FS_I(d_inode(dentry));
 884                 if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
 885                         _debug("AFS_VNODE_DELETED");
 886                 if (test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags))
 887                         _debug("AFS_VNODE_CB_BROKEN");
 888                 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
 889                 ret = afs_validate(vnode, key);
 890                 _debug("nlink %d [val %d]", vnode->vfs_inode.i_nlink, ret);
 891         }
 892
 893         key_put(key);
 894         _leave(" = 0");
 895         return 0;
 896
 897 remove_error:
 898         key_put(key);
 899 error:
 900         _leave(" = %d", ret);
 901         return ret;
 902 }
 903
 904 /*
 905  * create a regular file on an AFS filesystem
 906  */
 907 static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 908                       bool excl)
 909 {
 910         struct afs_file_status status;
 911         struct afs_callback cb;
 912         struct afs_server *server;
 913         struct afs_vnode *dvnode, *vnode;
 914         struct afs_fid fid;
 915         struct inode *inode;
 916         struct key *key;
 917         int ret;
 918
 919         dvnode = AFS_FS_I(dir);
 920
 921         _enter("{%x:%u},{%pd},%ho,",
 922                dvnode->fid.vid, dvnode->fid.vnode, dentry, mode);
 923
 924         key = afs_request_key(dvnode->volume->cell);
 925         if (IS_ERR(key)) {
 926                 ret = PTR_ERR(key);
 927                 goto error;
 928         }
 929
 930         mode |= S_IFREG;
 931         ret = afs_vnode_create(dvnode, key, dentry->d_name.name,
 932                                mode, &fid, &status, &cb, &server);
 933         if (ret < 0)
 934                 goto create_error;
 935
 936         inode = afs_iget(dir->i_sb, key, &fid, &status, &cb);
 937         if (IS_ERR(inode)) {
 938                 /* ENOMEM at a really inconvenient time - just abandon the new
 939                  * directory on the server */
 940                 ret = PTR_ERR(inode);
 941                 goto iget_error;
 942         }
 943
 944         /* apply the status report we've got for the new vnode */
 945         vnode = AFS_FS_I(inode);
 946         spin_lock(&vnode->lock);
 947         vnode->update_cnt++;
 948         spin_unlock(&vnode->lock);
 949         afs_vnode_finalise_status_update(vnode, server);
 950         afs_put_server(server);
 951
 952         d_instantiate(dentry, inode);
 953         if (d_unhashed(dentry)) {
 954                 _debug("not hashed");
 955                 d_rehash(dentry);
 956         }
 957         key_put(key);
 958         _leave(" = 0");
 959         return 0;
 960
 961 iget_error:
 962         afs_put_server(server);
 963 create_error:
 964         key_put(key);
 965 error:
 966         d_drop(dentry);
 967         _leave(" = %d", ret);
 968         return ret;
 969 }
 970
 971 /*
 972  * create a hard link between files in an AFS filesystem
 973  */
 974 static int afs_link(struct dentry *from, struct inode *dir,
 975                     struct dentry *dentry)
 976 {
 977         struct afs_vnode *dvnode, *vnode;
 978         struct key *key;
 979         int ret;
 980
 981         vnode = AFS_FS_I(d_inode(from));
 982         dvnode = AFS_FS_I(dir);
 983
 984         _enter("{%x:%u},{%x:%u},{%pd}",
 985                vnode->fid.vid, vnode->fid.vnode,
 986                dvnode->fid.vid, dvnode->fid.vnode,
 987                dentry);
 988
 989         key = afs_request_key(dvnode->volume->cell);
 990         if (IS_ERR(key)) {
 991                 ret = PTR_ERR(key);
 992                 goto error;
 993         }
 994
 995         ret = afs_vnode_link(dvnode, vnode, key, dentry->d_name.name);
 996         if (ret < 0)
 997                 goto link_error;
 998
 999         ihold(&vnode->vfs_inode);
1000         d_instantiate(dentry, &vnode->vfs_inode);
1001         key_put(key);
1002         _leave(" = 0");
1003         return 0;
1004
1005 link_error:
1006         key_put(key);
1007 error:
1008         d_drop(dentry);
1009         _leave(" = %d", ret);
1010         return ret;
1011 }
1012
1013 /*
1014  * create a symlink in an AFS filesystem
1015  */
1016 static int afs_symlink(struct inode *dir, struct dentry *dentry,
1017                        const char *content)
1018 {
1019         struct afs_file_status status;
1020         struct afs_server *server;
1021         struct afs_vnode *dvnode, *vnode;
1022         struct afs_fid fid;
1023         struct inode *inode;
1024         struct key *key;
1025         int ret;
1026
1027         dvnode = AFS_FS_I(dir);
1028
1029         _enter("{%x:%u},{%pd},%s",
1030                dvnode->fid.vid, dvnode->fid.vnode, dentry,
1031                content);
1032
1033         ret = -EINVAL;
1034         if (strlen(content) >= AFSPATHMAX)
1035                 goto error;
1036
1037         key = afs_request_key(dvnode->volume->cell);
1038         if (IS_ERR(key)) {
1039                 ret = PTR_ERR(key);
1040                 goto error;
1041         }
1042
1043         ret = afs_vnode_symlink(dvnode, key, dentry->d_name.name, content,
1044                                 &fid, &status, &server);
1045         if (ret < 0)
1046                 goto create_error;
1047
1048         inode = afs_iget(dir->i_sb, key, &fid, &status, NULL);
1049         if (IS_ERR(inode)) {
1050                 /* ENOMEM at a really inconvenient time - just abandon the new
1051                  * directory on the server */
1052                 ret = PTR_ERR(inode);
1053                 goto iget_error;
1054         }
1055
1056         /* apply the status report we've got for the new vnode */
1057         vnode = AFS_FS_I(inode);
1058         spin_lock(&vnode->lock);
1059         vnode->update_cnt++;
1060         spin_unlock(&vnode->lock);
1061         afs_vnode_finalise_status_update(vnode, server);
1062         afs_put_server(server);
1063
1064         d_instantiate(dentry, inode);
1065         if (d_unhashed(dentry)) {
1066                 _debug("not hashed");
1067                 d_rehash(dentry);
1068         }
1069         key_put(key);
1070         _leave(" = 0");
1071         return 0;
1072
1073 iget_error:
1074         afs_put_server(server);
1075 create_error:
1076         key_put(key);
1077 error:
1078         d_drop(dentry);
1079         _leave(" = %d", ret);
1080         return ret;
1081 }
1082
1083 /*
1084  * rename a file in an AFS filesystem and/or move it between directories
1085  */
1086 static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
1087                       struct inode *new_dir, struct dentry *new_dentry,
1088                       unsigned int flags)
1089 {
1090         struct afs_vnode *orig_dvnode, *new_dvnode, *vnode;
1091         struct key *key;
1092         int ret;
1093
1094         if (flags)
1095                 return -EINVAL;
1096
1097         vnode = AFS_FS_I(d_inode(old_dentry));
1098         orig_dvnode = AFS_FS_I(old_dir);
1099         new_dvnode = AFS_FS_I(new_dir);
1100
1101         _enter("{%x:%u},{%x:%u},{%x:%u},{%pd}",
1102                orig_dvnode->fid.vid, orig_dvnode->fid.vnode,
1103                vnode->fid.vid, vnode->fid.vnode,
1104                new_dvnode->fid.vid, new_dvnode->fid.vnode,
1105                new_dentry);
1106
1107         key = afs_request_key(orig_dvnode->volume->cell);
1108         if (IS_ERR(key)) {
1109                 ret = PTR_ERR(key);
1110                 goto error;
1111         }
1112
1113         ret = afs_vnode_rename(orig_dvnode, new_dvnode, key,
1114                                old_dentry->d_name.name,
1115                                new_dentry->d_name.name);
1116         if (ret < 0)
1117                 goto rename_error;
1118         key_put(key);
1119         _leave(" = 0");
1120         return 0;
1121
1122 rename_error:
1123         key_put(key);
1124 error:
1125         d_drop(new_dentry);
1126         _leave(" = %d", ret);
1127         return ret;
1128 }