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(void *_cookie, const char *name, int nlen,
  30                                   loff_t fpos, u64 ino, unsigned dtype);
  31 static int afs_create(struct inode *dir, struct dentry *dentry, 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(void *_cookie, const char *name, int nlen,
 395                               loff_t fpos, u64 ino, unsigned dtype)
 396 {
 397         struct afs_lookup_cookie *cookie = _cookie;
 398
 399         _enter("{%s,%u},%s,%u,,%llu,%u",
 400                cookie->name.name, cookie->name.len, name, nlen,
 401                (unsigned long long) ino, dtype);
 402
 403         /* insanity checks first */
 404         BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048);
 405         BUILD_BUG_ON(sizeof(union afs_dirent) != 32);
 406
 407         if (cookie->name.len != nlen ||
 408             memcmp(cookie->name.name, name, nlen) != 0) {
 409                 _leave(" = 0 [no]");
 410                 return 0;
 411         }
 412
 413         cookie->fid.vnode = ino;
 414         cookie->fid.unique = dtype;
 415         cookie->found = 1;
 416
 417         _leave(" = -1 [found]");
 418         return -1;
 419 }
 420
 421 /*
 422  * do a lookup in a directory
 423  * - just returns the FID the dentry name maps to if found
 424  */
 425 static int afs_do_lookup(struct inode *dir, struct dentry *dentry,
 426                          struct afs_fid *fid, struct key *key)
 427 {
 428         struct afs_super_info *as = dir->i_sb->s_fs_info;
 429         struct afs_lookup_cookie cookie = {
 430                 .ctx.actor = afs_lookup_filldir,
 431                 .name = dentry->d_name,
 432                 .fid.vid = as->volume->vid
 433         };
 434         int ret;
 435
 436         _enter("{%lu},%p{%s},", dir->i_ino, dentry, dentry->d_name.name);
 437
 438         /* search the directory */
 439         ret = afs_dir_iterate(dir, &cookie.ctx, key);
 440         if (ret < 0) {
 441                 _leave(" = %d [iter]", ret);
 442                 return ret;
 443         }
 444
 445         ret = -ENOENT;
 446         if (!cookie.found) {
 447                 _leave(" = -ENOENT [not found]");
 448                 return -ENOENT;
 449         }
 450
 451         *fid = cookie.fid;
 452         _leave(" = 0 { vn=%u u=%u }", fid->vnode, fid->unique);
 453         return 0;
 454 }
 455
 456 /*
 457  * Try to auto mount the mountpoint with pseudo directory, if the autocell
 458  * operation is setted.
 459  */
 460 static struct inode *afs_try_auto_mntpt(
 461         int ret, struct dentry *dentry, struct inode *dir, struct key *key,
 462         struct afs_fid *fid)
 463 {
 464         const char *devname = dentry->d_name.name;
 465         struct afs_vnode *vnode = AFS_FS_I(dir);
 466         struct inode *inode;
 467
 468         _enter("%d, %p{%s}, {%x:%u}, %p",
 469                ret, dentry, devname, vnode->fid.vid, vnode->fid.vnode, key);
 470
 471         if (ret != -ENOENT ||
 472             !test_bit(AFS_VNODE_AUTOCELL, &vnode->flags))
 473                 goto out;
 474
 475         inode = afs_iget_autocell(dir, devname, strlen(devname), key);
 476         if (IS_ERR(inode)) {
 477                 ret = PTR_ERR(inode);
 478                 goto out;
 479         }
 480
 481         *fid = AFS_FS_I(inode)->fid;
 482         _leave("= %p", inode);
 483         return inode;
 484
 485 out:
 486         _leave("= %d", ret);
 487         return ERR_PTR(ret);
 488 }
 489
 490 /*
 491  * look up an entry in a directory
 492  */
 493 static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
 494                                  unsigned int flags)
 495 {
 496         struct afs_vnode *vnode;
 497         struct afs_fid fid;
 498         struct inode *inode;
 499         struct key *key;
 500         int ret;
 501
 502         vnode = AFS_FS_I(dir);
 503
 504         _enter("{%x:%u},%p{%s},",
 505                vnode->fid.vid, vnode->fid.vnode, dentry, dentry->d_name.name);
 506
 507         ASSERTCMP(dentry->d_inode, ==, NULL);
 508
 509         if (dentry->d_name.len >= AFSNAMEMAX) {
 510                 _leave(" = -ENAMETOOLONG");
 511                 return ERR_PTR(-ENAMETOOLONG);
 512         }
 513
 514         if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
 515                 _leave(" = -ESTALE");
 516                 return ERR_PTR(-ESTALE);
 517         }
 518
 519         key = afs_request_key(vnode->volume->cell);
 520         if (IS_ERR(key)) {
 521                 _leave(" = %ld [key]", PTR_ERR(key));
 522                 return ERR_CAST(key);
 523         }
 524
 525         ret = afs_validate(vnode, key);
 526         if (ret < 0) {
 527                 key_put(key);
 528                 _leave(" = %d [val]", ret);
 529                 return ERR_PTR(ret);
 530         }
 531
 532         ret = afs_do_lookup(dir, dentry, &fid, key);
 533         if (ret < 0) {
 534                 inode = afs_try_auto_mntpt(ret, dentry, dir, key, &fid);
 535                 if (!IS_ERR(inode)) {
 536                         key_put(key);
 537                         goto success;
 538                 }
 539
 540                 ret = PTR_ERR(inode);
 541                 key_put(key);
 542                 if (ret == -ENOENT) {
 543                         d_add(dentry, NULL);
 544                         _leave(" = NULL [negative]");
 545                         return NULL;
 546                 }
 547                 _leave(" = %d [do]", ret);
 548                 return ERR_PTR(ret);
 549         }
 550         dentry->d_fsdata = (void *)(unsigned long) vnode->status.data_version;
 551
 552         /* instantiate the dentry */
 553         inode = afs_iget(dir->i_sb, key, &fid, NULL, NULL);
 554         key_put(key);
 555         if (IS_ERR(inode)) {
 556                 _leave(" = %ld", PTR_ERR(inode));
 557                 return ERR_CAST(inode);
 558         }
 559
 560 success:
 561         d_add(dentry, inode);
 562         _leave(" = 0 { vn=%u u=%u } -> { ino=%lu v=%u }",
 563                fid.vnode,
 564                fid.unique,
 565                dentry->d_inode->i_ino,
 566                dentry->d_inode->i_generation);
 567
 568         return NULL;
 569 }
 570
 571 /*
 572  * check that a dentry lookup hit has found a valid entry
 573  * - NOTE! the hit can be a negative hit too, so we can't assume we have an
 574  *   inode
 575  */
 576 static int afs_d_revalidate(struct dentry *dentry, unsigned int flags)
 577 {
 578         struct afs_vnode *vnode, *dir;
 579         struct afs_fid uninitialized_var(fid);
 580         struct dentry *parent;
 581         struct key *key;
 582         void *dir_version;
 583         int ret;
 584
 585         if (flags & LOOKUP_RCU)
 586                 return -ECHILD;
 587
 588         vnode = AFS_FS_I(dentry->d_inode);
 589
 590         if (dentry->d_inode)
 591                 _enter("{v={%x:%u} n=%s fl=%lx},",
 592                        vnode->fid.vid, vnode->fid.vnode, dentry->d_name.name,
 593                        vnode->flags);
 594         else
 595                 _enter("{neg n=%s}", dentry->d_name.name);
 596
 597         key = afs_request_key(AFS_FS_S(dentry->d_sb)->volume->cell);
 598         if (IS_ERR(key))
 599                 key = NULL;
 600
 601         /* lock down the parent dentry so we can peer at it */
 602         parent = dget_parent(dentry);
 603         dir = AFS_FS_I(parent->d_inode);
 604
 605         /* validate the parent directory */
 606         if (test_bit(AFS_VNODE_MODIFIED, &dir->flags))
 607                 afs_validate(dir, key);
 608
 609         if (test_bit(AFS_VNODE_DELETED, &dir->flags)) {
 610                 _debug("%s: parent dir deleted", dentry->d_name.name);
 611                 goto out_bad;
 612         }
 613
 614         dir_version = (void *) (unsigned long) dir->status.data_version;
 615         if (dentry->d_fsdata == dir_version)
 616                 goto out_valid; /* the dir contents are unchanged */
 617
 618         _debug("dir modified");
 619
 620         /* search the directory for this vnode */
 621         ret = afs_do_lookup(&dir->vfs_inode, dentry, &fid, key);
 622         switch (ret) {
 623         case 0:
 624                 /* the filename maps to something */
 625                 if (!dentry->d_inode)
 626                         goto out_bad;
 627                 if (is_bad_inode(dentry->d_inode)) {
 628                         printk("kAFS: afs_d_revalidate: %s/%s has bad inode\n",
 629                                parent->d_name.name, dentry->d_name.name);
 630                         goto out_bad;
 631                 }
 632
 633                 /* if the vnode ID has changed, then the dirent points to a
 634                  * different file */
 635                 if (fid.vnode != vnode->fid.vnode) {
 636                         _debug("%s: dirent changed [%u != %u]",
 637                                dentry->d_name.name, fid.vnode,
 638                                vnode->fid.vnode);
 639                         goto not_found;
 640                 }
 641
 642                 /* if the vnode ID uniqifier has changed, then the file has
 643                  * been deleted and replaced, and the original vnode ID has
 644                  * been reused */
 645                 if (fid.unique != vnode->fid.unique) {
 646                         _debug("%s: file deleted (uq %u -> %u I:%u)",
 647                                dentry->d_name.name, fid.unique,
 648                                vnode->fid.unique,
 649                                dentry->d_inode->i_generation);
 650                         spin_lock(&vnode->lock);
 651                         set_bit(AFS_VNODE_DELETED, &vnode->flags);
 652                         spin_unlock(&vnode->lock);
 653                         goto not_found;
 654                 }
 655                 goto out_valid;
 656
 657         case -ENOENT:
 658                 /* the filename is unknown */
 659                 _debug("%s: dirent not found", dentry->d_name.name);
 660                 if (dentry->d_inode)
 661                         goto not_found;
 662                 goto out_valid;
 663
 664         default:
 665                 _debug("failed to iterate dir %s: %d",
 666                        parent->d_name.name, ret);
 667                 goto out_bad;
 668         }
 669
 670 out_valid:
 671         dentry->d_fsdata = dir_version;
 672 out_skip:
 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         /* don't unhash if we have submounts */
 686         if (check_submounts_and_drop(dentry) != 0)
 687                 goto out_skip;
 688
 689         _debug("dropping dentry %s/%s",
 690                parent->d_name.name, dentry->d_name.name);
 691         dput(parent);
 692         key_put(key);
 693
 694         _leave(" = 0 [bad]");
 695         return 0;
 696 }
 697
 698 /*
 699  * allow the VFS to enquire as to whether a dentry should be unhashed (mustn't
 700  * sleep)
 701  * - called from dput() when d_count is going to 0.
 702  * - return 1 to request dentry be unhashed, 0 otherwise
 703  */
 704 static int afs_d_delete(const struct dentry *dentry)
 705 {
 706         _enter("%s", dentry->d_name.name);
 707
 708         if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
 709                 goto zap;
 710
 711         if (dentry->d_inode &&
 712             (test_bit(AFS_VNODE_DELETED,   &AFS_FS_I(dentry->d_inode)->flags) ||
 713              test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(dentry->d_inode)->flags)))
 714                 goto zap;
 715
 716         _leave(" = 0 [keep]");
 717         return 0;
 718
 719 zap:
 720         _leave(" = 1 [zap]");
 721         return 1;
 722 }
 723
 724 /*
 725  * handle dentry release
 726  */
 727 static void afs_d_release(struct dentry *dentry)
 728 {
 729         _enter("%s", dentry->d_name.name);
 730 }
 731
 732 /*
 733  * create a directory on an AFS filesystem
 734  */
 735 static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 736 {
 737         struct afs_file_status status;
 738         struct afs_callback cb;
 739         struct afs_server *server;
 740         struct afs_vnode *dvnode, *vnode;
 741         struct afs_fid fid;
 742         struct inode *inode;
 743         struct key *key;
 744         int ret;
 745
 746         dvnode = AFS_FS_I(dir);
 747
 748         _enter("{%x:%u},{%s},%ho",
 749                dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name, mode);
 750
 751         key = afs_request_key(dvnode->volume->cell);
 752         if (IS_ERR(key)) {
 753                 ret = PTR_ERR(key);
 754                 goto error;
 755         }
 756
 757         mode |= S_IFDIR;
 758         ret = afs_vnode_create(dvnode, key, dentry->d_name.name,
 759                                mode, &fid, &status, &cb, &server);
 760         if (ret < 0)
 761                 goto mkdir_error;
 762
 763         inode = afs_iget(dir->i_sb, key, &fid, &status, &cb);
 764         if (IS_ERR(inode)) {
 765                 /* ENOMEM at a really inconvenient time - just abandon the new
 766                  * directory on the server */
 767                 ret = PTR_ERR(inode);
 768                 goto iget_error;
 769         }
 770
 771         /* apply the status report we've got for the new vnode */
 772         vnode = AFS_FS_I(inode);
 773         spin_lock(&vnode->lock);
 774         vnode->update_cnt++;
 775         spin_unlock(&vnode->lock);
 776         afs_vnode_finalise_status_update(vnode, server);
 777         afs_put_server(server);
 778
 779         d_instantiate(dentry, inode);
 780         if (d_unhashed(dentry)) {
 781                 _debug("not hashed");
 782                 d_rehash(dentry);
 783         }
 784         key_put(key);
 785         _leave(" = 0");
 786         return 0;
 787
 788 iget_error:
 789         afs_put_server(server);
 790 mkdir_error:
 791         key_put(key);
 792 error:
 793         d_drop(dentry);
 794         _leave(" = %d", ret);
 795         return ret;
 796 }
 797
 798 /*
 799  * remove a directory from an AFS filesystem
 800  */
 801 static int afs_rmdir(struct inode *dir, struct dentry *dentry)
 802 {
 803         struct afs_vnode *dvnode, *vnode;
 804         struct key *key;
 805         int ret;
 806
 807         dvnode = AFS_FS_I(dir);
 808
 809         _enter("{%x:%u},{%s}",
 810                dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name);
 811
 812         key = afs_request_key(dvnode->volume->cell);
 813         if (IS_ERR(key)) {
 814                 ret = PTR_ERR(key);
 815                 goto error;
 816         }
 817
 818         ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, true);
 819         if (ret < 0)
 820                 goto rmdir_error;
 821
 822         if (dentry->d_inode) {
 823                 vnode = AFS_FS_I(dentry->d_inode);
 824                 clear_nlink(&vnode->vfs_inode);
 825                 set_bit(AFS_VNODE_DELETED, &vnode->flags);
 826                 afs_discard_callback_on_delete(vnode);
 827         }
 828
 829         key_put(key);
 830         _leave(" = 0");
 831         return 0;
 832
 833 rmdir_error:
 834         key_put(key);
 835 error:
 836         _leave(" = %d", ret);
 837         return ret;
 838 }
 839
 840 /*
 841  * remove a file from an AFS filesystem
 842  */
 843 static int afs_unlink(struct inode *dir, struct dentry *dentry)
 844 {
 845         struct afs_vnode *dvnode, *vnode;
 846         struct key *key;
 847         int ret;
 848
 849         dvnode = AFS_FS_I(dir);
 850
 851         _enter("{%x:%u},{%s}",
 852                dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name);
 853
 854         ret = -ENAMETOOLONG;
 855         if (dentry->d_name.len >= AFSNAMEMAX)
 856                 goto error;
 857
 858         key = afs_request_key(dvnode->volume->cell);
 859         if (IS_ERR(key)) {
 860                 ret = PTR_ERR(key);
 861                 goto error;
 862         }
 863
 864         if (dentry->d_inode) {
 865                 vnode = AFS_FS_I(dentry->d_inode);
 866
 867                 /* make sure we have a callback promise on the victim */
 868                 ret = afs_validate(vnode, key);
 869                 if (ret < 0)
 870                         goto error;
 871         }
 872
 873         ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, false);
 874         if (ret < 0)
 875                 goto remove_error;
 876
 877         if (dentry->d_inode) {
 878                 /* if the file wasn't deleted due to excess hard links, the
 879                  * fileserver will break the callback promise on the file - if
 880                  * it had one - before it returns to us, and if it was deleted,
 881                  * it won't
 882                  *
 883                  * however, if we didn't have a callback promise outstanding,
 884                  * or it was outstanding on a different server, then it won't
 885                  * break it either...
 886                  */
 887                 vnode = AFS_FS_I(dentry->d_inode);
 888                 if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
 889                         _debug("AFS_VNODE_DELETED");
 890                 if (test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags))
 891                         _debug("AFS_VNODE_CB_BROKEN");
 892                 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
 893                 ret = afs_validate(vnode, key);
 894                 _debug("nlink %d [val %d]", vnode->vfs_inode.i_nlink, ret);
 895         }
 896
 897         key_put(key);
 898         _leave(" = 0");
 899         return 0;
 900
 901 remove_error:
 902         key_put(key);
 903 error:
 904         _leave(" = %d", ret);
 905         return ret;
 906 }
 907
 908 /*
 909  * create a regular file on an AFS filesystem
 910  */
 911 static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 912                       bool excl)
 913 {
 914         struct afs_file_status status;
 915         struct afs_callback cb;
 916         struct afs_server *server;
 917         struct afs_vnode *dvnode, *vnode;
 918         struct afs_fid fid;
 919         struct inode *inode;
 920         struct key *key;
 921         int ret;
 922
 923         dvnode = AFS_FS_I(dir);
 924
 925         _enter("{%x:%u},{%s},%ho,",
 926                dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name, mode);
 927
 928         key = afs_request_key(dvnode->volume->cell);
 929         if (IS_ERR(key)) {
 930                 ret = PTR_ERR(key);
 931                 goto error;
 932         }
 933
 934         mode |= S_IFREG;
 935         ret = afs_vnode_create(dvnode, key, dentry->d_name.name,
 936                                mode, &fid, &status, &cb, &server);
 937         if (ret < 0)
 938                 goto create_error;
 939
 940         inode = afs_iget(dir->i_sb, key, &fid, &status, &cb);
 941         if (IS_ERR(inode)) {
 942                 /* ENOMEM at a really inconvenient time - just abandon the new
 943                  * directory on the server */
 944                 ret = PTR_ERR(inode);
 945                 goto iget_error;
 946         }
 947
 948         /* apply the status report we've got for the new vnode */
 949         vnode = AFS_FS_I(inode);
 950         spin_lock(&vnode->lock);
 951         vnode->update_cnt++;
 952         spin_unlock(&vnode->lock);
 953         afs_vnode_finalise_status_update(vnode, server);
 954         afs_put_server(server);
 955
 956         d_instantiate(dentry, inode);
 957         if (d_unhashed(dentry)) {
 958                 _debug("not hashed");
 959                 d_rehash(dentry);
 960         }
 961         key_put(key);
 962         _leave(" = 0");
 963         return 0;
 964
 965 iget_error:
 966         afs_put_server(server);
 967 create_error:
 968         key_put(key);
 969 error:
 970         d_drop(dentry);
 971         _leave(" = %d", ret);
 972         return ret;
 973 }
 974
 975 /*
 976  * create a hard link between files in an AFS filesystem
 977  */
 978 static int afs_link(struct dentry *from, struct inode *dir,
 979                     struct dentry *dentry)
 980 {
 981         struct afs_vnode *dvnode, *vnode;
 982         struct key *key;
 983         int ret;
 984
 985         vnode = AFS_FS_I(from->d_inode);
 986         dvnode = AFS_FS_I(dir);
 987
 988         _enter("{%x:%u},{%x:%u},{%s}",
 989                vnode->fid.vid, vnode->fid.vnode,
 990                dvnode->fid.vid, dvnode->fid.vnode,
 991                dentry->d_name.name);
 992
 993         key = afs_request_key(dvnode->volume->cell);
 994         if (IS_ERR(key)) {
 995                 ret = PTR_ERR(key);
 996                 goto error;
 997         }
 998
 999         ret = afs_vnode_link(dvnode, vnode, key, dentry->d_name.name);
1000         if (ret < 0)
1001                 goto link_error;
1002
1003         ihold(&vnode->vfs_inode);
1004         d_instantiate(dentry, &vnode->vfs_inode);
1005         key_put(key);
1006         _leave(" = 0");
1007         return 0;
1008
1009 link_error:
1010         key_put(key);
1011 error:
1012         d_drop(dentry);
1013         _leave(" = %d", ret);
1014         return ret;
1015 }
1016
1017 /*
1018  * create a symlink in an AFS filesystem
1019  */
1020 static int afs_symlink(struct inode *dir, struct dentry *dentry,
1021                        const char *content)
1022 {
1023         struct afs_file_status status;
1024         struct afs_server *server;
1025         struct afs_vnode *dvnode, *vnode;
1026         struct afs_fid fid;
1027         struct inode *inode;
1028         struct key *key;
1029         int ret;
1030
1031         dvnode = AFS_FS_I(dir);
1032
1033         _enter("{%x:%u},{%s},%s",
1034                dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name,
1035                content);
1036
1037         ret = -EINVAL;
1038         if (strlen(content) >= AFSPATHMAX)
1039                 goto error;
1040
1041         key = afs_request_key(dvnode->volume->cell);
1042         if (IS_ERR(key)) {
1043                 ret = PTR_ERR(key);
1044                 goto error;
1045         }
1046
1047         ret = afs_vnode_symlink(dvnode, key, dentry->d_name.name, content,
1048                                 &fid, &status, &server);
1049         if (ret < 0)
1050                 goto create_error;
1051
1052         inode = afs_iget(dir->i_sb, key, &fid, &status, NULL);
1053         if (IS_ERR(inode)) {
1054                 /* ENOMEM at a really inconvenient time - just abandon the new
1055                  * directory on the server */
1056                 ret = PTR_ERR(inode);
1057                 goto iget_error;
1058         }
1059
1060         /* apply the status report we've got for the new vnode */
1061         vnode = AFS_FS_I(inode);
1062         spin_lock(&vnode->lock);
1063         vnode->update_cnt++;
1064         spin_unlock(&vnode->lock);
1065         afs_vnode_finalise_status_update(vnode, server);
1066         afs_put_server(server);
1067
1068         d_instantiate(dentry, inode);
1069         if (d_unhashed(dentry)) {
1070                 _debug("not hashed");
1071                 d_rehash(dentry);
1072         }
1073         key_put(key);
1074         _leave(" = 0");
1075         return 0;
1076
1077 iget_error:
1078         afs_put_server(server);
1079 create_error:
1080         key_put(key);
1081 error:
1082         d_drop(dentry);
1083         _leave(" = %d", ret);
1084         return ret;
1085 }
1086
1087 /*
1088  * rename a file in an AFS filesystem and/or move it between directories
1089  */
1090 static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
1091                       struct inode *new_dir, struct dentry *new_dentry)
1092 {
1093         struct afs_vnode *orig_dvnode, *new_dvnode, *vnode;
1094         struct key *key;
1095         int ret;
1096
1097         vnode = AFS_FS_I(old_dentry->d_inode);
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},{%s}",
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->d_name.name);
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 }