fs/afs/dir.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* dir.c: AFS filesystem directory handling
   3  *
   4  * Copyright (C) 2002, 2018 Red Hat, Inc. All Rights Reserved.
   5  * Written by David Howells (dhowells@redhat.com)
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/fs.h>
  10 #include <linux/namei.h>
  11 #include <linux/pagemap.h>
  12 #include <linux/swap.h>
  13 #include <linux/ctype.h>
  14 #include <linux/sched.h>
  15 #include <linux/task_io_accounting_ops.h>
  16 #include "internal.h"
  17 #include "afs_fs.h"
  18 #include "xdr_fs.h"
  19
  20 static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
  21                                  unsigned int flags);
  22 static int afs_dir_open(struct inode *inode, struct file *file);
  23 static int afs_readdir(struct file *file, struct dir_context *ctx);
  24 static int afs_d_revalidate(struct dentry *dentry, unsigned int flags);
  25 static int afs_d_delete(const struct dentry *dentry);
  26 static void afs_d_iput(struct dentry *dentry, struct inode *inode);
  27 static int afs_lookup_one_filldir(struct dir_context *ctx, const char *name, int nlen,
  28                                   loff_t fpos, u64 ino, unsigned dtype);
  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 static int afs_dir_releasepage(struct page *page, gfp_t gfp_flags);
  44 static void afs_dir_invalidatepage(struct page *page, unsigned int offset,
  45                                    unsigned int length);
  46
  47 static int afs_dir_set_page_dirty(struct page *page)
  48 {
  49         BUG(); /* This should never happen. */
  50 }
  51
  52 const struct file_operations afs_dir_file_operations = {
  53         .open           = afs_dir_open,
  54         .release        = afs_release,
  55         .iterate_shared = afs_readdir,
  56         .lock           = afs_lock,
  57         .llseek         = generic_file_llseek,
  58 };
  59
  60 const struct inode_operations afs_dir_inode_operations = {
  61         .create         = afs_create,
  62         .lookup         = afs_lookup,
  63         .link           = afs_link,
  64         .unlink         = afs_unlink,
  65         .symlink        = afs_symlink,
  66         .mkdir          = afs_mkdir,
  67         .rmdir          = afs_rmdir,
  68         .rename         = afs_rename,
  69         .permission     = afs_permission,
  70         .getattr        = afs_getattr,
  71         .setattr        = afs_setattr,
  72         .listxattr      = afs_listxattr,
  73 };
  74
  75 const struct address_space_operations afs_dir_aops = {
  76         .set_page_dirty = afs_dir_set_page_dirty,
  77         .releasepage    = afs_dir_releasepage,
  78         .invalidatepage = afs_dir_invalidatepage,
  79 };
  80
  81 const struct dentry_operations afs_fs_dentry_operations = {
  82         .d_revalidate   = afs_d_revalidate,
  83         .d_delete       = afs_d_delete,
  84         .d_release      = afs_d_release,
  85         .d_automount    = afs_d_automount,
  86         .d_iput         = afs_d_iput,
  87 };
  88
  89 struct afs_lookup_one_cookie {
  90         struct dir_context      ctx;
  91         struct qstr             name;
  92         bool                    found;
  93         struct afs_fid          fid;
  94 };
  95
  96 struct afs_lookup_cookie {
  97         struct dir_context      ctx;
  98         struct qstr             name;
  99         bool                    found;
 100         bool                    one_only;
 101         unsigned short          nr_fids;
 102         struct inode            **inodes;
 103         struct afs_status_cb    *statuses;
 104         struct afs_fid          fids[50];
 105 };
 106
 107 /*
 108  * check that a directory page is valid
 109  */
 110 static bool afs_dir_check_page(struct afs_vnode *dvnode, struct page *page,
 111                                loff_t i_size)
 112 {
 113         struct afs_xdr_dir_page *dbuf;
 114         loff_t latter, off;
 115         int tmp, qty;
 116
 117         /* Determine how many magic numbers there should be in this page, but
 118          * we must take care because the directory may change size under us.
 119          */
 120         off = page_offset(page);
 121         if (i_size <= off)
 122                 goto checked;
 123
 124         latter = i_size - off;
 125         if (latter >= PAGE_SIZE)
 126                 qty = PAGE_SIZE;
 127         else
 128                 qty = latter;
 129         qty /= sizeof(union afs_xdr_dir_block);
 130
 131         /* check them */
 132         dbuf = kmap(page);
 133         for (tmp = 0; tmp < qty; tmp++) {
 134                 if (dbuf->blocks[tmp].hdr.magic != AFS_DIR_MAGIC) {
 135                         printk("kAFS: %s(%lx): bad magic %d/%d is %04hx\n",
 136                                __func__, dvnode->vfs_inode.i_ino, tmp, qty,
 137                                ntohs(dbuf->blocks[tmp].hdr.magic));
 138                         trace_afs_dir_check_failed(dvnode, off, i_size);
 139                         kunmap(page);
 140                         trace_afs_file_error(dvnode, -EIO, afs_file_error_dir_bad_magic);
 141                         goto error;
 142                 }
 143
 144                 /* Make sure each block is NUL terminated so we can reasonably
 145                  * use string functions on it.  The filenames in the page
 146                  * *should* be NUL-terminated anyway.
 147                  */
 148                 ((u8 *)&dbuf->blocks[tmp])[AFS_DIR_BLOCK_SIZE - 1] = 0;
 149         }
 150
 151         kunmap(page);
 152
 153 checked:
 154         afs_stat_v(dvnode, n_read_dir);
 155         return true;
 156
 157 error:
 158         return false;
 159 }
 160
 161 /*
 162  * Check the contents of a directory that we've just read.
 163  */
 164 static bool afs_dir_check_pages(struct afs_vnode *dvnode, struct afs_read *req)
 165 {
 166         struct afs_xdr_dir_page *dbuf;
 167         unsigned int i, j, qty = PAGE_SIZE / sizeof(union afs_xdr_dir_block);
 168
 169         for (i = 0; i < req->nr_pages; i++)
 170                 if (!afs_dir_check_page(dvnode, req->pages[i], req->actual_len))
 171                         goto bad;
 172         return true;
 173
 174 bad:
 175         pr_warn("DIR %llx:%llx f=%llx l=%llx al=%llx r=%llx\n",
 176                 dvnode->fid.vid, dvnode->fid.vnode,
 177                 req->file_size, req->len, req->actual_len, req->remain);
 178         pr_warn("DIR %llx %x %x %x\n",
 179                 req->pos, req->index, req->nr_pages, req->offset);
 180
 181         for (i = 0; i < req->nr_pages; i++) {
 182                 dbuf = kmap(req->pages[i]);
 183                 for (j = 0; j < qty; j++) {
 184                         union afs_xdr_dir_block *block = &dbuf->blocks[j];
 185
 186                         pr_warn("[%02x] %32phN\n", i * qty + j, block);
 187                 }
 188                 kunmap(req->pages[i]);
 189         }
 190         return false;
 191 }
 192
 193 /*
 194  * open an AFS directory file
 195  */
 196 static int afs_dir_open(struct inode *inode, struct file *file)
 197 {
 198         _enter("{%lu}", inode->i_ino);
 199
 200         BUILD_BUG_ON(sizeof(union afs_xdr_dir_block) != 2048);
 201         BUILD_BUG_ON(sizeof(union afs_xdr_dirent) != 32);
 202
 203         if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(inode)->flags))
 204                 return -ENOENT;
 205
 206         return afs_open(inode, file);
 207 }
 208
 209 /*
 210  * Read the directory into the pagecache in one go, scrubbing the previous
 211  * contents.  The list of pages is returned, pinning them so that they don't
 212  * get reclaimed during the iteration.
 213  */
 214 static struct afs_read *afs_read_dir(struct afs_vnode *dvnode, struct key *key)
 215         __acquires(&dvnode->validate_lock)
 216 {
 217         struct afs_read *req;
 218         loff_t i_size;
 219         int nr_pages, nr_inline, i, n;
 220         int ret = -ENOMEM;
 221
 222 retry:
 223         i_size = i_size_read(&dvnode->vfs_inode);
 224         if (i_size < 2048)
 225                 return ERR_PTR(afs_bad(dvnode, afs_file_error_dir_small));
 226         if (i_size > 2048 * 1024) {
 227                 trace_afs_file_error(dvnode, -EFBIG, afs_file_error_dir_big);
 228                 return ERR_PTR(-EFBIG);
 229         }
 230
 231         _enter("%llu", i_size);
 232
 233         /* Get a request record to hold the page list.  We want to hold it
 234          * inline if we can, but we don't want to make an order 1 allocation.
 235          */
 236         nr_pages = (i_size + PAGE_SIZE - 1) / PAGE_SIZE;
 237         nr_inline = nr_pages;
 238         if (nr_inline > (PAGE_SIZE - sizeof(*req)) / sizeof(struct page *))
 239                 nr_inline = 0;
 240
 241         req = kzalloc(struct_size(req, array, nr_inline), GFP_KERNEL);
 242         if (!req)
 243                 return ERR_PTR(-ENOMEM);
 244
 245         refcount_set(&req->usage, 1);
 246         req->nr_pages = nr_pages;
 247         req->actual_len = i_size; /* May change */
 248         req->len = nr_pages * PAGE_SIZE; /* We can ask for more than there is */
 249         req->data_version = dvnode->status.data_version; /* May change */
 250         if (nr_inline > 0) {
 251                 req->pages = req->array;
 252         } else {
 253                 req->pages = kcalloc(nr_pages, sizeof(struct page *),
 254                                      GFP_KERNEL);
 255                 if (!req->pages)
 256                         goto error;
 257         }
 258
 259         /* Get a list of all the pages that hold or will hold the directory
 260          * content.  We need to fill in any gaps that we might find where the
 261          * memory reclaimer has been at work.  If there are any gaps, we will
 262          * need to reread the entire directory contents.
 263          */
 264         i = 0;
 265         do {
 266                 n = find_get_pages_contig(dvnode->vfs_inode.i_mapping, i,
 267                                           req->nr_pages - i,
 268                                           req->pages + i);
 269                 _debug("find %u at %u/%u", n, i, req->nr_pages);
 270                 if (n == 0) {
 271                         gfp_t gfp = dvnode->vfs_inode.i_mapping->gfp_mask;
 272
 273                         if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
 274                                 afs_stat_v(dvnode, n_inval);
 275
 276                         ret = -ENOMEM;
 277                         req->pages[i] = __page_cache_alloc(gfp);
 278                         if (!req->pages[i])
 279                                 goto error;
 280                         ret = add_to_page_cache_lru(req->pages[i],
 281                                                     dvnode->vfs_inode.i_mapping,
 282                                                     i, gfp);
 283                         if (ret < 0)
 284                                 goto error;
 285
 286                         set_page_private(req->pages[i], 1);
 287                         SetPagePrivate(req->pages[i]);
 288                         unlock_page(req->pages[i]);
 289                         i++;
 290                 } else {
 291                         i += n;
 292                 }
 293         } while (i < req->nr_pages);
 294
 295         /* If we're going to reload, we need to lock all the pages to prevent
 296          * races.
 297          */
 298         ret = -ERESTARTSYS;
 299         if (down_read_killable(&dvnode->validate_lock) < 0)
 300                 goto error;
 301
 302         if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
 303                 goto success;
 304
 305         up_read(&dvnode->validate_lock);
 306         if (down_write_killable(&dvnode->validate_lock) < 0)
 307                 goto error;
 308
 309         if (!test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags)) {
 310                 trace_afs_reload_dir(dvnode);
 311                 ret = afs_fetch_data(dvnode, key, req);
 312                 if (ret < 0)
 313                         goto error_unlock;
 314
 315                 task_io_account_read(PAGE_SIZE * req->nr_pages);
 316
 317                 if (req->len < req->file_size)
 318                         goto content_has_grown;
 319
 320                 /* Validate the data we just read. */
 321                 ret = -EIO;
 322                 if (!afs_dir_check_pages(dvnode, req))
 323                         goto error_unlock;
 324
 325                 // TODO: Trim excess pages
 326
 327                 set_bit(AFS_VNODE_DIR_VALID, &dvnode->flags);
 328         }
 329
 330         downgrade_write(&dvnode->validate_lock);
 331 success:
 332         return req;
 333
 334 error_unlock:
 335         up_write(&dvnode->validate_lock);
 336 error:
 337         afs_put_read(req);
 338         _leave(" = %d", ret);
 339         return ERR_PTR(ret);
 340
 341 content_has_grown:
 342         up_write(&dvnode->validate_lock);
 343         afs_put_read(req);
 344         goto retry;
 345 }
 346
 347 /*
 348  * deal with one block in an AFS directory
 349  */
 350 static int afs_dir_iterate_block(struct afs_vnode *dvnode,
 351                                  struct dir_context *ctx,
 352                                  union afs_xdr_dir_block *block,
 353                                  unsigned blkoff)
 354 {
 355         union afs_xdr_dirent *dire;
 356         unsigned offset, next, curr;
 357         size_t nlen;
 358         int tmp;
 359
 360         _enter("%u,%x,%p,,",(unsigned)ctx->pos,blkoff,block);
 361
 362         curr = (ctx->pos - blkoff) / sizeof(union afs_xdr_dirent);
 363
 364         /* walk through the block, an entry at a time */
 365         for (offset = (blkoff == 0 ? AFS_DIR_RESV_BLOCKS0 : AFS_DIR_RESV_BLOCKS);
 366              offset < AFS_DIR_SLOTS_PER_BLOCK;
 367              offset = next
 368              ) {
 369                 next = offset + 1;
 370
 371                 /* skip entries marked unused in the bitmap */
 372                 if (!(block->hdr.bitmap[offset / 8] &
 373                       (1 << (offset % 8)))) {
 374                         _debug("ENT[%zu.%u]: unused",
 375                                blkoff / sizeof(union afs_xdr_dir_block), offset);
 376                         if (offset >= curr)
 377                                 ctx->pos = blkoff +
 378                                         next * sizeof(union afs_xdr_dirent);
 379                         continue;
 380                 }
 381
 382                 /* got a valid entry */
 383                 dire = &block->dirents[offset];
 384                 nlen = strnlen(dire->u.name,
 385                                sizeof(*block) -
 386                                offset * sizeof(union afs_xdr_dirent));
 387
 388                 _debug("ENT[%zu.%u]: %s %zu \"%s\"",
 389                        blkoff / sizeof(union afs_xdr_dir_block), offset,
 390                        (offset < curr ? "skip" : "fill"),
 391                        nlen, dire->u.name);
 392
 393                 /* work out where the next possible entry is */
 394                 for (tmp = nlen; tmp > 15; tmp -= sizeof(union afs_xdr_dirent)) {
 395                         if (next >= AFS_DIR_SLOTS_PER_BLOCK) {
 396                                 _debug("ENT[%zu.%u]:"
 397                                        " %u travelled beyond end dir block"
 398                                        " (len %u/%zu)",
 399                                        blkoff / sizeof(union afs_xdr_dir_block),
 400                                        offset, next, tmp, nlen);
 401                                 return afs_bad(dvnode, afs_file_error_dir_over_end);
 402                         }
 403                         if (!(block->hdr.bitmap[next / 8] &
 404                               (1 << (next % 8)))) {
 405                                 _debug("ENT[%zu.%u]:"
 406                                        " %u unmarked extension (len %u/%zu)",
 407                                        blkoff / sizeof(union afs_xdr_dir_block),
 408                                        offset, next, tmp, nlen);
 409                                 return afs_bad(dvnode, afs_file_error_dir_unmarked_ext);
 410                         }
 411
 412                         _debug("ENT[%zu.%u]: ext %u/%zu",
 413                                blkoff / sizeof(union afs_xdr_dir_block),
 414                                next, tmp, nlen);
 415                         next++;
 416                 }
 417
 418                 /* skip if starts before the current position */
 419                 if (offset < curr)
 420                         continue;
 421
 422                 /* found the next entry */
 423                 if (!dir_emit(ctx, dire->u.name, nlen,
 424                               ntohl(dire->u.vnode),
 425                               (ctx->actor == afs_lookup_filldir ||
 426                                ctx->actor == afs_lookup_one_filldir)?
 427                               ntohl(dire->u.unique) : DT_UNKNOWN)) {
 428                         _leave(" = 0 [full]");
 429                         return 0;
 430                 }
 431
 432                 ctx->pos = blkoff + next * sizeof(union afs_xdr_dirent);
 433         }
 434
 435         _leave(" = 1 [more]");
 436         return 1;
 437 }
 438
 439 /*
 440  * iterate through the data blob that lists the contents of an AFS directory
 441  */
 442 static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx,
 443                            struct key *key, afs_dataversion_t *_dir_version)
 444 {
 445         struct afs_vnode *dvnode = AFS_FS_I(dir);
 446         struct afs_xdr_dir_page *dbuf;
 447         union afs_xdr_dir_block *dblock;
 448         struct afs_read *req;
 449         struct page *page;
 450         unsigned blkoff, limit;
 451         int ret;
 452
 453         _enter("{%lu},%u,,", dir->i_ino, (unsigned)ctx->pos);
 454
 455         if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(dir)->flags)) {
 456                 _leave(" = -ESTALE");
 457                 return -ESTALE;
 458         }
 459
 460         req = afs_read_dir(dvnode, key);
 461         if (IS_ERR(req))
 462                 return PTR_ERR(req);
 463         *_dir_version = req->data_version;
 464
 465         /* round the file position up to the next entry boundary */
 466         ctx->pos += sizeof(union afs_xdr_dirent) - 1;
 467         ctx->pos &= ~(sizeof(union afs_xdr_dirent) - 1);
 468
 469         /* walk through the blocks in sequence */
 470         ret = 0;
 471         while (ctx->pos < req->actual_len) {
 472                 blkoff = ctx->pos & ~(sizeof(union afs_xdr_dir_block) - 1);
 473
 474                 /* Fetch the appropriate page from the directory and re-add it
 475                  * to the LRU.
 476                  */
 477                 page = req->pages[blkoff / PAGE_SIZE];
 478                 if (!page) {
 479                         ret = afs_bad(dvnode, afs_file_error_dir_missing_page);
 480                         break;
 481                 }
 482                 mark_page_accessed(page);
 483
 484                 limit = blkoff & ~(PAGE_SIZE - 1);
 485
 486                 dbuf = kmap(page);
 487
 488                 /* deal with the individual blocks stashed on this page */
 489                 do {
 490                         dblock = &dbuf->blocks[(blkoff % PAGE_SIZE) /
 491                                                sizeof(union afs_xdr_dir_block)];
 492                         ret = afs_dir_iterate_block(dvnode, ctx, dblock, blkoff);
 493                         if (ret != 1) {
 494                                 kunmap(page);
 495                                 goto out;
 496                         }
 497
 498                         blkoff += sizeof(union afs_xdr_dir_block);
 499
 500                 } while (ctx->pos < dir->i_size && blkoff < limit);
 501
 502                 kunmap(page);
 503                 ret = 0;
 504         }
 505
 506 out:
 507         up_read(&dvnode->validate_lock);
 508         afs_put_read(req);
 509         _leave(" = %d", ret);
 510         return ret;
 511 }
 512
 513 /*
 514  * read an AFS directory
 515  */
 516 static int afs_readdir(struct file *file, struct dir_context *ctx)
 517 {
 518         afs_dataversion_t dir_version;
 519
 520         return afs_dir_iterate(file_inode(file), ctx, afs_file_key(file),
 521                                &dir_version);
 522 }
 523
 524 /*
 525  * Search the directory for a single name
 526  * - if afs_dir_iterate_block() spots this function, it'll pass the FID
 527  *   uniquifier through dtype
 528  */
 529 static int afs_lookup_one_filldir(struct dir_context *ctx, const char *name,
 530                                   int nlen, loff_t fpos, u64 ino, unsigned dtype)
 531 {
 532         struct afs_lookup_one_cookie *cookie =
 533                 container_of(ctx, struct afs_lookup_one_cookie, ctx);
 534
 535         _enter("{%s,%u},%s,%u,,%llu,%u",
 536                cookie->name.name, cookie->name.len, name, nlen,
 537                (unsigned long long) ino, dtype);
 538
 539         /* insanity checks first */
 540         BUILD_BUG_ON(sizeof(union afs_xdr_dir_block) != 2048);
 541         BUILD_BUG_ON(sizeof(union afs_xdr_dirent) != 32);
 542
 543         if (cookie->name.len != nlen ||
 544             memcmp(cookie->name.name, name, nlen) != 0) {
 545                 _leave(" = 0 [no]");
 546                 return 0;
 547         }
 548
 549         cookie->fid.vnode = ino;
 550         cookie->fid.unique = dtype;
 551         cookie->found = 1;
 552
 553         _leave(" = -1 [found]");
 554         return -1;
 555 }
 556
 557 /*
 558  * Do a lookup of a single name in a directory
 559  * - just returns the FID the dentry name maps to if found
 560  */
 561 static int afs_do_lookup_one(struct inode *dir, struct dentry *dentry,
 562                              struct afs_fid *fid, struct key *key,
 563                              afs_dataversion_t *_dir_version)
 564 {
 565         struct afs_super_info *as = dir->i_sb->s_fs_info;
 566         struct afs_lookup_one_cookie cookie = {
 567                 .ctx.actor = afs_lookup_one_filldir,
 568                 .name = dentry->d_name,
 569                 .fid.vid = as->volume->vid
 570         };
 571         int ret;
 572
 573         _enter("{%lu},%p{%pd},", dir->i_ino, dentry, dentry);
 574
 575         /* search the directory */
 576         ret = afs_dir_iterate(dir, &cookie.ctx, key, _dir_version);
 577         if (ret < 0) {
 578                 _leave(" = %d [iter]", ret);
 579                 return ret;
 580         }
 581
 582         ret = -ENOENT;
 583         if (!cookie.found) {
 584                 _leave(" = -ENOENT [not found]");
 585                 return -ENOENT;
 586         }
 587
 588         *fid = cookie.fid;
 589         _leave(" = 0 { vn=%llu u=%u }", fid->vnode, fid->unique);
 590         return 0;
 591 }
 592
 593 /*
 594  * search the directory for a name
 595  * - if afs_dir_iterate_block() spots this function, it'll pass the FID
 596  *   uniquifier through dtype
 597  */
 598 static int afs_lookup_filldir(struct dir_context *ctx, const char *name,
 599                               int nlen, loff_t fpos, u64 ino, unsigned dtype)
 600 {
 601         struct afs_lookup_cookie *cookie =
 602                 container_of(ctx, struct afs_lookup_cookie, ctx);
 603         int ret;
 604
 605         _enter("{%s,%u},%s,%u,,%llu,%u",
 606                cookie->name.name, cookie->name.len, name, nlen,
 607                (unsigned long long) ino, dtype);
 608
 609         /* insanity checks first */
 610         BUILD_BUG_ON(sizeof(union afs_xdr_dir_block) != 2048);
 611         BUILD_BUG_ON(sizeof(union afs_xdr_dirent) != 32);
 612
 613         if (cookie->found) {
 614                 if (cookie->nr_fids < 50) {
 615                         cookie->fids[cookie->nr_fids].vnode     = ino;
 616                         cookie->fids[cookie->nr_fids].unique    = dtype;
 617                         cookie->nr_fids++;
 618                 }
 619         } else if (cookie->name.len == nlen &&
 620                    memcmp(cookie->name.name, name, nlen) == 0) {
 621                 cookie->fids[0].vnode   = ino;
 622                 cookie->fids[0].unique  = dtype;
 623                 cookie->found = 1;
 624                 if (cookie->one_only)
 625                         return -1;
 626         }
 627
 628         ret = cookie->nr_fids >= 50 ? -1 : 0;
 629         _leave(" = %d", ret);
 630         return ret;
 631 }
 632
 633 /*
 634  * Do a lookup in a directory.  We make use of bulk lookup to query a slew of
 635  * files in one go and create inodes for them.  The inode of the file we were
 636  * asked for is returned.
 637  */
 638 static struct inode *afs_do_lookup(struct inode *dir, struct dentry *dentry,
 639                                    struct key *key)
 640 {
 641         struct afs_lookup_cookie *cookie;
 642         struct afs_cb_interest *dcbi, *cbi = NULL;
 643         struct afs_super_info *as = dir->i_sb->s_fs_info;
 644         struct afs_status_cb *scb;
 645         struct afs_iget_data iget_data;
 646         struct afs_fs_cursor fc;
 647         struct afs_server *server;
 648         struct afs_vnode *dvnode = AFS_FS_I(dir), *vnode;
 649         struct inode *inode = NULL, *ti;
 650         afs_dataversion_t data_version = READ_ONCE(dvnode->status.data_version);
 651         int ret, i;
 652
 653         _enter("{%lu},%p{%pd},", dir->i_ino, dentry, dentry);
 654
 655         cookie = kzalloc(sizeof(struct afs_lookup_cookie), GFP_KERNEL);
 656         if (!cookie)
 657                 return ERR_PTR(-ENOMEM);
 658
 659         cookie->ctx.actor = afs_lookup_filldir;
 660         cookie->name = dentry->d_name;
 661         cookie->nr_fids = 1; /* slot 0 is saved for the fid we actually want */
 662
 663         read_seqlock_excl(&dvnode->cb_lock);
 664         dcbi = rcu_dereference_protected(dvnode->cb_interest,
 665                                          lockdep_is_held(&dvnode->cb_lock.lock));
 666         if (dcbi) {
 667                 server = dcbi->server;
 668                 if (server &&
 669                     test_bit(AFS_SERVER_FL_NO_IBULK, &server->flags))
 670                         cookie->one_only = true;
 671         }
 672         read_sequnlock_excl(&dvnode->cb_lock);
 673
 674         for (i = 0; i < 50; i++)
 675                 cookie->fids[i].vid = as->volume->vid;
 676
 677         /* search the directory */
 678         ret = afs_dir_iterate(dir, &cookie->ctx, key, &data_version);
 679         if (ret < 0) {
 680                 inode = ERR_PTR(ret);
 681                 goto out;
 682         }
 683
 684         dentry->d_fsdata = (void *)(unsigned long)data_version;
 685
 686         inode = ERR_PTR(-ENOENT);
 687         if (!cookie->found)
 688                 goto out;
 689
 690         /* Check to see if we already have an inode for the primary fid. */
 691         iget_data.fid = cookie->fids[0];
 692         iget_data.volume = dvnode->volume;
 693         iget_data.cb_v_break = dvnode->volume->cb_v_break;
 694         iget_data.cb_s_break = 0;
 695         inode = ilookup5(dir->i_sb, cookie->fids[0].vnode,
 696                          afs_iget5_test, &iget_data);
 697         if (inode)
 698                 goto out;
 699
 700         /* Need space for examining all the selected files */
 701         inode = ERR_PTR(-ENOMEM);
 702         cookie->statuses = kvcalloc(cookie->nr_fids, sizeof(struct afs_status_cb),
 703                                     GFP_KERNEL);
 704         if (!cookie->statuses)
 705                 goto out;
 706
 707         cookie->inodes = kcalloc(cookie->nr_fids, sizeof(struct inode *),
 708                                  GFP_KERNEL);
 709         if (!cookie->inodes)
 710                 goto out_s;
 711
 712         for (i = 1; i < cookie->nr_fids; i++) {
 713                 scb = &cookie->statuses[i];
 714
 715                 /* Find any inodes that already exist and get their
 716                  * callback counters.
 717                  */
 718                 iget_data.fid = cookie->fids[i];
 719                 ti = ilookup5_nowait(dir->i_sb, iget_data.fid.vnode,
 720                                      afs_iget5_test, &iget_data);
 721                 if (!IS_ERR_OR_NULL(ti)) {
 722                         vnode = AFS_FS_I(ti);
 723                         scb->cb_break = afs_calc_vnode_cb_break(vnode);
 724                         cookie->inodes[i] = ti;
 725                 }
 726         }
 727
 728         /* Try FS.InlineBulkStatus first.  Abort codes for the individual
 729          * lookups contained therein are stored in the reply without aborting
 730          * the whole operation.
 731          */
 732         if (cookie->one_only)
 733                 goto no_inline_bulk_status;
 734
 735         inode = ERR_PTR(-ERESTARTSYS);
 736         if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
 737                 while (afs_select_fileserver(&fc)) {
 738                         if (test_bit(AFS_SERVER_FL_NO_IBULK,
 739                                       &fc.cbi->server->flags)) {
 740                                 fc.ac.abort_code = RX_INVALID_OPERATION;
 741                                 fc.ac.error = -ECONNABORTED;
 742                                 break;
 743                         }
 744                         iget_data.cb_v_break = dvnode->volume->cb_v_break;
 745                         iget_data.cb_s_break = fc.cbi->server->cb_s_break;
 746                         afs_fs_inline_bulk_status(&fc,
 747                                                   afs_v2net(dvnode),
 748                                                   cookie->fids,
 749                                                   cookie->statuses,
 750                                                   cookie->nr_fids, NULL);
 751                 }
 752
 753                 if (fc.ac.error == 0)
 754                         cbi = afs_get_cb_interest(fc.cbi);
 755                 if (fc.ac.abort_code == RX_INVALID_OPERATION)
 756                         set_bit(AFS_SERVER_FL_NO_IBULK, &fc.cbi->server->flags);
 757                 inode = ERR_PTR(afs_end_vnode_operation(&fc));
 758         }
 759
 760         if (!IS_ERR(inode))
 761                 goto success;
 762         if (fc.ac.abort_code != RX_INVALID_OPERATION)
 763                 goto out_c;
 764
 765 no_inline_bulk_status:
 766         /* We could try FS.BulkStatus next, but this aborts the entire op if
 767          * any of the lookups fails - so, for the moment, revert to
 768          * FS.FetchStatus for just the primary fid.
 769          */
 770         inode = ERR_PTR(-ERESTARTSYS);
 771         if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
 772                 while (afs_select_fileserver(&fc)) {
 773                         iget_data.cb_v_break = dvnode->volume->cb_v_break;
 774                         iget_data.cb_s_break = fc.cbi->server->cb_s_break;
 775                         scb = &cookie->statuses[0];
 776                         afs_fs_fetch_status(&fc,
 777                                             afs_v2net(dvnode),
 778                                             cookie->fids,
 779                                             scb,
 780                                             NULL);
 781                 }
 782
 783                 if (fc.ac.error == 0)
 784                         cbi = afs_get_cb_interest(fc.cbi);
 785                 inode = ERR_PTR(afs_end_vnode_operation(&fc));
 786         }
 787
 788         if (IS_ERR(inode))
 789                 goto out_c;
 790
 791 success:
 792         /* Turn all the files into inodes and save the first one - which is the
 793          * one we actually want.
 794          */
 795         scb = &cookie->statuses[0];
 796         if (scb->status.abort_code != 0)
 797                 inode = ERR_PTR(afs_abort_to_error(scb->status.abort_code));
 798
 799         for (i = 0; i < cookie->nr_fids; i++) {
 800                 struct afs_status_cb *scb = &cookie->statuses[i];
 801
 802                 if (!scb->have_status && !scb->have_error)
 803                         continue;
 804
 805                 if (cookie->inodes[i]) {
 806                         struct afs_vnode *iv = AFS_FS_I(cookie->inodes[i]);
 807
 808                         if (test_bit(AFS_VNODE_UNSET, &iv->flags))
 809                                 continue;
 810
 811                         afs_vnode_commit_status(&fc, iv,
 812                                                 scb->cb_break, NULL, scb);
 813                         continue;
 814                 }
 815
 816                 if (scb->status.abort_code != 0)
 817                         continue;
 818
 819                 iget_data.fid = cookie->fids[i];
 820                 ti = afs_iget(dir->i_sb, key, &iget_data, scb, cbi, dvnode);
 821                 if (!IS_ERR(ti))
 822                         afs_cache_permit(AFS_FS_I(ti), key,
 823                                          0 /* Assume vnode->cb_break is 0 */ +
 824                                          iget_data.cb_v_break,
 825                                          scb);
 826                 if (i == 0) {
 827                         inode = ti;
 828                 } else {
 829                         if (!IS_ERR(ti))
 830                                 iput(ti);
 831                 }
 832         }
 833
 834 out_c:
 835         afs_put_cb_interest(afs_v2net(dvnode), cbi);
 836         if (cookie->inodes) {
 837                 for (i = 0; i < cookie->nr_fids; i++)
 838                         iput(cookie->inodes[i]);
 839                 kfree(cookie->inodes);
 840         }
 841 out_s:
 842         kvfree(cookie->statuses);
 843 out:
 844         kfree(cookie);
 845         return inode;
 846 }
 847
 848 /*
 849  * Look up an entry in a directory with @sys substitution.
 850  */
 851 static struct dentry *afs_lookup_atsys(struct inode *dir, struct dentry *dentry,
 852                                        struct key *key)
 853 {
 854         struct afs_sysnames *subs;
 855         struct afs_net *net = afs_i2net(dir);
 856         struct dentry *ret;
 857         char *buf, *p, *name;
 858         int len, i;
 859
 860         _enter("");
 861
 862         ret = ERR_PTR(-ENOMEM);
 863         p = buf = kmalloc(AFSNAMEMAX, GFP_KERNEL);
 864         if (!buf)
 865                 goto out_p;
 866         if (dentry->d_name.len > 4) {
 867                 memcpy(p, dentry->d_name.name, dentry->d_name.len - 4);
 868                 p += dentry->d_name.len - 4;
 869         }
 870
 871         /* There is an ordered list of substitutes that we have to try. */
 872         read_lock(&net->sysnames_lock);
 873         subs = net->sysnames;
 874         refcount_inc(&subs->usage);
 875         read_unlock(&net->sysnames_lock);
 876
 877         for (i = 0; i < subs->nr; i++) {
 878                 name = subs->subs[i];
 879                 len = dentry->d_name.len - 4 + strlen(name);
 880                 if (len >= AFSNAMEMAX) {
 881                         ret = ERR_PTR(-ENAMETOOLONG);
 882                         goto out_s;
 883                 }
 884
 885                 strcpy(p, name);
 886                 ret = lookup_one_len(buf, dentry->d_parent, len);
 887                 if (IS_ERR(ret) || d_is_positive(ret))
 888                         goto out_s;
 889                 dput(ret);
 890         }
 891
 892         /* We don't want to d_add() the @sys dentry here as we don't want to
 893          * the cached dentry to hide changes to the sysnames list.
 894          */
 895         ret = NULL;
 896 out_s:
 897         afs_put_sysnames(subs);
 898         kfree(buf);
 899 out_p:
 900         key_put(key);
 901         return ret;
 902 }
 903
 904 /*
 905  * look up an entry in a directory
 906  */
 907 static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
 908                                  unsigned int flags)
 909 {
 910         struct afs_vnode *dvnode = AFS_FS_I(dir);
 911         struct afs_fid fid = {};
 912         struct inode *inode;
 913         struct dentry *d;
 914         struct key *key;
 915         int ret;
 916
 917         _enter("{%llx:%llu},%p{%pd},",
 918                dvnode->fid.vid, dvnode->fid.vnode, dentry, dentry);
 919
 920         ASSERTCMP(d_inode(dentry), ==, NULL);
 921
 922         if (dentry->d_name.len >= AFSNAMEMAX) {
 923                 _leave(" = -ENAMETOOLONG");
 924                 return ERR_PTR(-ENAMETOOLONG);
 925         }
 926
 927         if (test_bit(AFS_VNODE_DELETED, &dvnode->flags)) {
 928                 _leave(" = -ESTALE");
 929                 return ERR_PTR(-ESTALE);
 930         }
 931
 932         key = afs_request_key(dvnode->volume->cell);
 933         if (IS_ERR(key)) {
 934                 _leave(" = %ld [key]", PTR_ERR(key));
 935                 return ERR_CAST(key);
 936         }
 937
 938         ret = afs_validate(dvnode, key);
 939         if (ret < 0) {
 940                 key_put(key);
 941                 _leave(" = %d [val]", ret);
 942                 return ERR_PTR(ret);
 943         }
 944
 945         if (dentry->d_name.len >= 4 &&
 946             dentry->d_name.name[dentry->d_name.len - 4] == '@' &&
 947             dentry->d_name.name[dentry->d_name.len - 3] == 's' &&
 948             dentry->d_name.name[dentry->d_name.len - 2] == 'y' &&
 949             dentry->d_name.name[dentry->d_name.len - 1] == 's')
 950                 return afs_lookup_atsys(dir, dentry, key);
 951
 952         afs_stat_v(dvnode, n_lookup);
 953         inode = afs_do_lookup(dir, dentry, key);
 954         key_put(key);
 955         if (inode == ERR_PTR(-ENOENT))
 956                 inode = afs_try_auto_mntpt(dentry, dir);
 957
 958         if (!IS_ERR_OR_NULL(inode))
 959                 fid = AFS_FS_I(inode)->fid;
 960
 961         d = d_splice_alias(inode, dentry);
 962         if (!IS_ERR_OR_NULL(d)) {
 963                 d->d_fsdata = dentry->d_fsdata;
 964                 trace_afs_lookup(dvnode, &d->d_name, &fid);
 965         } else {
 966                 trace_afs_lookup(dvnode, &dentry->d_name, &fid);
 967         }
 968         return d;
 969 }
 970
 971 /*
 972  * Check the validity of a dentry under RCU conditions.
 973  */
 974 static int afs_d_revalidate_rcu(struct dentry *dentry)
 975 {
 976         struct afs_vnode *dvnode, *vnode;
 977         struct dentry *parent;
 978         struct inode *dir, *inode;
 979         long dir_version, de_version;
 980
 981         _enter("%p", dentry);
 982
 983         /* Check the parent directory is still valid first. */
 984         parent = READ_ONCE(dentry->d_parent);
 985         dir = d_inode_rcu(parent);
 986         if (!dir)
 987                 return -ECHILD;
 988         dvnode = AFS_FS_I(dir);
 989         if (test_bit(AFS_VNODE_DELETED, &dvnode->flags))
 990                 return -ECHILD;
 991
 992         if (!afs_check_validity(dvnode))
 993                 return -ECHILD;
 994
 995         /* We only need to invalidate a dentry if the server's copy changed
 996          * behind our back.  If we made the change, it's no problem.  Note that
 997          * on a 32-bit system, we only have 32 bits in the dentry to store the
 998          * version.
 999          */
1000         dir_version = (long)READ_ONCE(dvnode->status.data_version);
1001         de_version = (long)READ_ONCE(dentry->d_fsdata);
1002         if (de_version != dir_version) {
1003                 dir_version = (long)READ_ONCE(dvnode->invalid_before);
1004                 if (de_version - dir_version < 0)
1005                         return -ECHILD;
1006         }
1007
1008         /* Check to see if the vnode referred to by the dentry still
1009          * has a callback.
1010          */
1011         if (d_really_is_positive(dentry)) {
1012                 inode = d_inode_rcu(dentry);
1013                 if (inode) {
1014                         vnode = AFS_FS_I(inode);
1015                         if (!afs_check_validity(vnode))
1016                                 return -ECHILD;
1017                 }
1018         }
1019
1020         return 1; /* Still valid */
1021 }
1022
1023 /*
1024  * check that a dentry lookup hit has found a valid entry
1025  * - NOTE! the hit can be a negative hit too, so we can't assume we have an
1026  *   inode
1027  */
1028 static int afs_d_revalidate(struct dentry *dentry, unsigned int flags)
1029 {
1030         struct afs_vnode *vnode, *dir;
1031         struct afs_fid uninitialized_var(fid);
1032         struct dentry *parent;
1033         struct inode *inode;
1034         struct key *key;
1035         afs_dataversion_t dir_version, invalid_before;
1036         long de_version;
1037         int ret;
1038
1039         if (flags & LOOKUP_RCU)
1040                 return afs_d_revalidate_rcu(dentry);
1041
1042         if (d_really_is_positive(dentry)) {
1043                 vnode = AFS_FS_I(d_inode(dentry));
1044                 _enter("{v={%llx:%llu} n=%pd fl=%lx},",
1045                        vnode->fid.vid, vnode->fid.vnode, dentry,
1046                        vnode->flags);
1047         } else {
1048                 _enter("{neg n=%pd}", dentry);
1049         }
1050
1051         key = afs_request_key(AFS_FS_S(dentry->d_sb)->volume->cell);
1052         if (IS_ERR(key))
1053                 key = NULL;
1054
1055         if (d_really_is_positive(dentry)) {
1056                 inode = d_inode(dentry);
1057                 if (inode) {
1058                         vnode = AFS_FS_I(inode);
1059                         afs_validate(vnode, key);
1060                         if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
1061                                 goto out_bad;
1062                 }
1063         }
1064
1065         /* lock down the parent dentry so we can peer at it */
1066         parent = dget_parent(dentry);
1067         dir = AFS_FS_I(d_inode(parent));
1068
1069         /* validate the parent directory */
1070         afs_validate(dir, key);
1071
1072         if (test_bit(AFS_VNODE_DELETED, &dir->flags)) {
1073                 _debug("%pd: parent dir deleted", dentry);
1074                 goto out_bad_parent;
1075         }
1076
1077         /* We only need to invalidate a dentry if the server's copy changed
1078          * behind our back.  If we made the change, it's no problem.  Note that
1079          * on a 32-bit system, we only have 32 bits in the dentry to store the
1080          * version.
1081          */
1082         dir_version = dir->status.data_version;
1083         de_version = (long)dentry->d_fsdata;
1084         if (de_version == (long)dir_version)
1085                 goto out_valid_noupdate;
1086
1087         invalid_before = dir->invalid_before;
1088         if (de_version - (long)invalid_before >= 0)
1089                 goto out_valid;
1090
1091         _debug("dir modified");
1092         afs_stat_v(dir, n_reval);
1093
1094         /* search the directory for this vnode */
1095         ret = afs_do_lookup_one(&dir->vfs_inode, dentry, &fid, key, &dir_version);
1096         switch (ret) {
1097         case 0:
1098                 /* the filename maps to something */
1099                 if (d_really_is_negative(dentry))
1100                         goto out_bad_parent;
1101                 inode = d_inode(dentry);
1102                 if (is_bad_inode(inode)) {
1103                         printk("kAFS: afs_d_revalidate: %pd2 has bad inode\n",
1104                                dentry);
1105                         goto out_bad_parent;
1106                 }
1107
1108                 vnode = AFS_FS_I(inode);
1109
1110                 /* if the vnode ID has changed, then the dirent points to a
1111                  * different file */
1112                 if (fid.vnode != vnode->fid.vnode) {
1113                         _debug("%pd: dirent changed [%llu != %llu]",
1114                                dentry, fid.vnode,
1115                                vnode->fid.vnode);
1116                         goto not_found;
1117                 }
1118
1119                 /* if the vnode ID uniqifier has changed, then the file has
1120                  * been deleted and replaced, and the original vnode ID has
1121                  * been reused */
1122                 if (fid.unique != vnode->fid.unique) {
1123                         _debug("%pd: file deleted (uq %u -> %u I:%u)",
1124                                dentry, fid.unique,
1125                                vnode->fid.unique,
1126                                vnode->vfs_inode.i_generation);
1127                         write_seqlock(&vnode->cb_lock);
1128                         set_bit(AFS_VNODE_DELETED, &vnode->flags);
1129                         write_sequnlock(&vnode->cb_lock);
1130                         goto not_found;
1131                 }
1132                 goto out_valid;
1133
1134         case -ENOENT:
1135                 /* the filename is unknown */
1136                 _debug("%pd: dirent not found", dentry);
1137                 if (d_really_is_positive(dentry))
1138                         goto not_found;
1139                 goto out_valid;
1140
1141         default:
1142                 _debug("failed to iterate dir %pd: %d",
1143                        parent, ret);
1144                 goto out_bad_parent;
1145         }
1146
1147 out_valid:
1148         dentry->d_fsdata = (void *)(unsigned long)dir_version;
1149 out_valid_noupdate:
1150         dput(parent);
1151         key_put(key);
1152         _leave(" = 1 [valid]");
1153         return 1;
1154
1155         /* the dirent, if it exists, now points to a different vnode */
1156 not_found:
1157         spin_lock(&dentry->d_lock);
1158         dentry->d_flags |= DCACHE_NFSFS_RENAMED;
1159         spin_unlock(&dentry->d_lock);
1160
1161 out_bad_parent:
1162         _debug("dropping dentry %pd2", dentry);
1163         dput(parent);
1164 out_bad:
1165         key_put(key);
1166
1167         _leave(" = 0 [bad]");
1168         return 0;
1169 }
1170
1171 /*
1172  * allow the VFS to enquire as to whether a dentry should be unhashed (mustn't
1173  * sleep)
1174  * - called from dput() when d_count is going to 0.
1175  * - return 1 to request dentry be unhashed, 0 otherwise
1176  */
1177 static int afs_d_delete(const struct dentry *dentry)
1178 {
1179         _enter("%pd", dentry);
1180
1181         if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
1182                 goto zap;
1183
1184         if (d_really_is_positive(dentry) &&
1185             (test_bit(AFS_VNODE_DELETED,   &AFS_FS_I(d_inode(dentry))->flags) ||
1186              test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(d_inode(dentry))->flags)))
1187                 goto zap;
1188
1189         _leave(" = 0 [keep]");
1190         return 0;
1191
1192 zap:
1193         _leave(" = 1 [zap]");
1194         return 1;
1195 }
1196
1197 /*
1198  * Clean up sillyrename files on dentry removal.
1199  */
1200 static void afs_d_iput(struct dentry *dentry, struct inode *inode)
1201 {
1202         if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
1203                 afs_silly_iput(dentry, inode);
1204         iput(inode);
1205 }
1206
1207 /*
1208  * handle dentry release
1209  */
1210 void afs_d_release(struct dentry *dentry)
1211 {
1212         _enter("%pd", dentry);
1213 }
1214
1215 /*
1216  * Create a new inode for create/mkdir/symlink
1217  */
1218 static void afs_vnode_new_inode(struct afs_fs_cursor *fc,
1219                                 struct dentry *new_dentry,
1220                                 struct afs_iget_data *new_data,
1221                                 struct afs_status_cb *new_scb)
1222 {
1223         struct afs_vnode *vnode;
1224         struct inode *inode;
1225
1226         if (fc->ac.error < 0)
1227                 return;
1228
1229         inode = afs_iget(fc->vnode->vfs_inode.i_sb, fc->key,
1230                          new_data, new_scb, fc->cbi, fc->vnode);
1231         if (IS_ERR(inode)) {
1232                 /* ENOMEM or EINTR at a really inconvenient time - just abandon
1233                  * the new directory on the server.
1234                  */
1235                 fc->ac.error = PTR_ERR(inode);
1236                 return;
1237         }
1238
1239         vnode = AFS_FS_I(inode);
1240         set_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags);
1241         if (fc->ac.error == 0)
1242                 afs_cache_permit(vnode, fc->key, vnode->cb_break, new_scb);
1243         d_instantiate(new_dentry, inode);
1244 }
1245
1246 static void afs_prep_for_new_inode(struct afs_fs_cursor *fc,
1247                                    struct afs_iget_data *iget_data)
1248 {
1249         iget_data->volume = fc->vnode->volume;
1250         iget_data->cb_v_break = fc->vnode->volume->cb_v_break;
1251         iget_data->cb_s_break = fc->cbi->server->cb_s_break;
1252 }
1253
1254 /*
1255  * Note that a dentry got changed.  We need to set d_fsdata to the data version
1256  * number derived from the result of the operation.  It doesn't matter if
1257  * d_fsdata goes backwards as we'll just revalidate.
1258  */
1259 static void afs_update_dentry_version(struct afs_fs_cursor *fc,
1260                                       struct dentry *dentry,
1261                                       struct afs_status_cb *scb)
1262 {
1263         if (fc->ac.error == 0)
1264                 dentry->d_fsdata =
1265                         (void *)(unsigned long)scb->status.data_version;
1266 }
1267
1268 /*
1269  * create a directory on an AFS filesystem
1270  */
1271 static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
1272 {
1273         struct afs_iget_data iget_data;
1274         struct afs_status_cb *scb;
1275         struct afs_fs_cursor fc;
1276         struct afs_vnode *dvnode = AFS_FS_I(dir);
1277         struct key *key;
1278         afs_dataversion_t data_version;
1279         int ret;
1280
1281         mode |= S_IFDIR;
1282
1283         _enter("{%llx:%llu},{%pd},%ho",
1284                dvnode->fid.vid, dvnode->fid.vnode, dentry, mode);
1285
1286         ret = -ENOMEM;
1287         scb = kcalloc(2, sizeof(struct afs_status_cb), GFP_KERNEL);
1288         if (!scb)
1289                 goto error;
1290
1291         key = afs_request_key(dvnode->volume->cell);
1292         if (IS_ERR(key)) {
1293                 ret = PTR_ERR(key);
1294                 goto error_scb;
1295         }
1296
1297         ret = -ERESTARTSYS;
1298         if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
1299                 data_version = dvnode->status.data_version + 1;
1300
1301                 while (afs_select_fileserver(&fc)) {
1302                         fc.cb_break = afs_calc_vnode_cb_break(dvnode);
1303                         afs_prep_for_new_inode(&fc, &iget_data);
1304                         afs_fs_create(&fc, dentry->d_name.name, mode,
1305                                       &scb[0], &iget_data.fid, &scb[1]);
1306                 }
1307
1308                 afs_check_for_remote_deletion(&fc, dvnode);
1309                 afs_vnode_commit_status(&fc, dvnode, fc.cb_break,
1310                                         &data_version, &scb[0]);
1311                 afs_update_dentry_version(&fc, dentry, &scb[0]);
1312                 afs_vnode_new_inode(&fc, dentry, &iget_data, &scb[1]);
1313                 ret = afs_end_vnode_operation(&fc);
1314                 if (ret < 0)
1315                         goto error_key;
1316         } else {
1317                 goto error_key;
1318         }
1319
1320         if (ret == 0) {
1321                 down_write(&dvnode->validate_lock);
1322                 if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags) &&
1323                     dvnode->status.data_version == data_version)
1324                         afs_edit_dir_add(dvnode, &dentry->d_name, &iget_data.fid,
1325                                          afs_edit_dir_for_create);
1326                 up_write(&dvnode->validate_lock);
1327         }
1328
1329         key_put(key);
1330         kfree(scb);
1331         _leave(" = 0");
1332         return 0;
1333
1334 error_key:
1335         key_put(key);
1336 error_scb:
1337         kfree(scb);
1338 error:
1339         d_drop(dentry);
1340         _leave(" = %d", ret);
1341         return ret;
1342 }
1343
1344 /*
1345  * Remove a subdir from a directory.
1346  */
1347 static void afs_dir_remove_subdir(struct dentry *dentry)
1348 {
1349         if (d_really_is_positive(dentry)) {
1350                 struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
1351
1352                 clear_nlink(&vnode->vfs_inode);
1353                 set_bit(AFS_VNODE_DELETED, &vnode->flags);
1354                 clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
1355                 clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags);
1356         }
1357 }
1358
1359 /*
1360  * remove a directory from an AFS filesystem
1361  */
1362 static int afs_rmdir(struct inode *dir, struct dentry *dentry)
1363 {
1364         struct afs_status_cb *scb;
1365         struct afs_fs_cursor fc;
1366         struct afs_vnode *dvnode = AFS_FS_I(dir), *vnode = NULL;
1367         struct key *key;
1368         afs_dataversion_t data_version;
1369         int ret;
1370
1371         _enter("{%llx:%llu},{%pd}",
1372                dvnode->fid.vid, dvnode->fid.vnode, dentry);
1373
1374         scb = kzalloc(sizeof(struct afs_status_cb), GFP_KERNEL);
1375         if (!scb)
1376                 return -ENOMEM;
1377
1378         key = afs_request_key(dvnode->volume->cell);
1379         if (IS_ERR(key)) {
1380                 ret = PTR_ERR(key);
1381                 goto error;
1382         }
1383
1384         /* Try to make sure we have a callback promise on the victim. */
1385         if (d_really_is_positive(dentry)) {
1386                 vnode = AFS_FS_I(d_inode(dentry));
1387                 ret = afs_validate(vnode, key);
1388                 if (ret < 0)
1389                         goto error_key;
1390         }
1391
1392         if (vnode) {
1393                 ret = down_write_killable(&vnode->rmdir_lock);
1394                 if (ret < 0)
1395                         goto error_key;
1396         }
1397
1398         ret = -ERESTARTSYS;
1399         if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
1400                 data_version = dvnode->status.data_version + 1;
1401
1402                 while (afs_select_fileserver(&fc)) {
1403                         fc.cb_break = afs_calc_vnode_cb_break(dvnode);
1404                         afs_fs_remove(&fc, vnode, dentry->d_name.name, true, scb);
1405                 }
1406
1407                 afs_vnode_commit_status(&fc, dvnode, fc.cb_break,
1408                                         &data_version, scb);
1409                 afs_update_dentry_version(&fc, dentry, scb);
1410                 ret = afs_end_vnode_operation(&fc);
1411                 if (ret == 0) {
1412                         afs_dir_remove_subdir(dentry);
1413                         down_write(&dvnode->validate_lock);
1414                         if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags) &&
1415                             dvnode->status.data_version == data_version)
1416                                 afs_edit_dir_remove(dvnode, &dentry->d_name,
1417                                                     afs_edit_dir_for_rmdir);
1418                         up_write(&dvnode->validate_lock);
1419                 }
1420         }
1421
1422         if (vnode)
1423                 up_write(&vnode->rmdir_lock);
1424 error_key:
1425         key_put(key);
1426 error:
1427         kfree(scb);
1428         return ret;
1429 }
1430
1431 /*
1432  * Remove a link to a file or symlink from a directory.
1433  *
1434  * If the file was not deleted due to excess hard links, the fileserver will
1435  * break the callback promise on the file - if it had one - before it returns
1436  * to us, and if it was deleted, it won't
1437  *
1438  * However, if we didn't have a callback promise outstanding, or it was
1439  * outstanding on a different server, then it won't break it either...
1440  */
1441 static int afs_dir_remove_link(struct afs_vnode *dvnode, struct dentry *dentry,
1442                                struct key *key)
1443 {
1444         int ret = 0;
1445
1446         if (d_really_is_positive(dentry)) {
1447                 struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
1448
1449                 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
1450                         /* Already done */
1451                 } else if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags)) {
1452                         write_seqlock(&vnode->cb_lock);
1453                         drop_nlink(&vnode->vfs_inode);
1454                         if (vnode->vfs_inode.i_nlink == 0) {
1455                                 set_bit(AFS_VNODE_DELETED, &vnode->flags);
1456                                 __afs_break_callback(vnode, afs_cb_break_for_unlink);
1457                         }
1458                         write_sequnlock(&vnode->cb_lock);
1459                         ret = 0;
1460                 } else {
1461                         afs_break_callback(vnode, afs_cb_break_for_unlink);
1462
1463                         if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
1464                                 kdebug("AFS_VNODE_DELETED");
1465
1466                         ret = afs_validate(vnode, key);
1467                         if (ret == -ESTALE)
1468                                 ret = 0;
1469                 }
1470                 _debug("nlink %d [val %d]", vnode->vfs_inode.i_nlink, ret);
1471         }
1472
1473         return ret;
1474 }
1475
1476 /*
1477  * Remove a file or symlink from an AFS filesystem.
1478  */
1479 static int afs_unlink(struct inode *dir, struct dentry *dentry)
1480 {
1481         struct afs_fs_cursor fc;
1482         struct afs_status_cb *scb;
1483         struct afs_vnode *dvnode = AFS_FS_I(dir);
1484         struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
1485         struct key *key;
1486         bool need_rehash = false;
1487         int ret;
1488
1489         _enter("{%llx:%llu},{%pd}",
1490                dvnode->fid.vid, dvnode->fid.vnode, dentry);
1491
1492         if (dentry->d_name.len >= AFSNAMEMAX)
1493                 return -ENAMETOOLONG;
1494
1495         ret = -ENOMEM;
1496         scb = kcalloc(2, sizeof(struct afs_status_cb), GFP_KERNEL);
1497         if (!scb)
1498                 goto error;
1499
1500         key = afs_request_key(dvnode->volume->cell);
1501         if (IS_ERR(key)) {
1502                 ret = PTR_ERR(key);
1503                 goto error_scb;
1504         }
1505
1506         /* Try to make sure we have a callback promise on the victim. */
1507         ret = afs_validate(vnode, key);
1508         if (ret < 0)
1509                 goto error_key;
1510
1511         spin_lock(&dentry->d_lock);
1512         if (d_count(dentry) > 1) {
1513                 spin_unlock(&dentry->d_lock);
1514                 /* Start asynchronous writeout of the inode */
1515                 write_inode_now(d_inode(dentry), 0);
1516                 ret = afs_sillyrename(dvnode, vnode, dentry, key);
1517                 goto error_key;
1518         }
1519         if (!d_unhashed(dentry)) {
1520                 /* Prevent a race with RCU lookup. */
1521                 __d_drop(dentry);
1522                 need_rehash = true;
1523         }
1524         spin_unlock(&dentry->d_lock);
1525
1526         ret = -ERESTARTSYS;
1527         if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
1528                 afs_dataversion_t data_version = dvnode->status.data_version + 1;
1529                 afs_dataversion_t data_version_2 = vnode->status.data_version;
1530
1531                 while (afs_select_fileserver(&fc)) {
1532                         fc.cb_break = afs_calc_vnode_cb_break(dvnode);
1533                         fc.cb_break_2 = afs_calc_vnode_cb_break(vnode);
1534
1535                         if (test_bit(AFS_SERVER_FL_IS_YFS, &fc.cbi->server->flags) &&
1536                             !test_bit(AFS_SERVER_FL_NO_RM2, &fc.cbi->server->flags)) {
1537                                 yfs_fs_remove_file2(&fc, vnode, dentry->d_name.name,
1538                                                     &scb[0], &scb[1]);
1539                                 if (fc.ac.error != -ECONNABORTED ||
1540                                     fc.ac.abort_code != RXGEN_OPCODE)
1541                                         continue;
1542                                 set_bit(AFS_SERVER_FL_NO_RM2, &fc.cbi->server->flags);
1543                         }
1544
1545                         afs_fs_remove(&fc, vnode, dentry->d_name.name, false, &scb[0]);
1546                 }
1547
1548                 afs_vnode_commit_status(&fc, dvnode, fc.cb_break,
1549                                         &data_version, &scb[0]);
1550                 afs_vnode_commit_status(&fc, vnode, fc.cb_break_2,
1551                                         &data_version_2, &scb[1]);
1552                 afs_update_dentry_version(&fc, dentry, &scb[0]);
1553                 ret = afs_end_vnode_operation(&fc);
1554                 if (ret == 0 && !(scb[1].have_status || scb[1].have_error))
1555                         ret = afs_dir_remove_link(dvnode, dentry, key);
1556
1557                 if (ret == 0) {
1558                         down_write(&dvnode->validate_lock);
1559                         if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags) &&
1560                             dvnode->status.data_version == data_version)
1561                                 afs_edit_dir_remove(dvnode, &dentry->d_name,
1562                                                     afs_edit_dir_for_unlink);
1563                         up_write(&dvnode->validate_lock);
1564                 }
1565         }
1566
1567         if (need_rehash && ret < 0 && ret != -ENOENT)
1568                 d_rehash(dentry);
1569
1570 error_key:
1571         key_put(key);
1572 error_scb:
1573         kfree(scb);
1574 error:
1575         _leave(" = %d", ret);
1576         return ret;
1577 }
1578
1579 /*
1580  * create a regular file on an AFS filesystem
1581  */
1582 static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
1583                       bool excl)
1584 {
1585         struct afs_iget_data iget_data;
1586         struct afs_fs_cursor fc;
1587         struct afs_status_cb *scb;
1588         struct afs_vnode *dvnode = AFS_FS_I(dir);
1589         struct key *key;
1590         afs_dataversion_t data_version;
1591         int ret;
1592
1593         mode |= S_IFREG;
1594
1595         _enter("{%llx:%llu},{%pd},%ho,",
1596                dvnode->fid.vid, dvnode->fid.vnode, dentry, mode);
1597
1598         ret = -ENAMETOOLONG;
1599         if (dentry->d_name.len >= AFSNAMEMAX)
1600                 goto error;
1601
1602         key = afs_request_key(dvnode->volume->cell);
1603         if (IS_ERR(key)) {
1604                 ret = PTR_ERR(key);
1605                 goto error;
1606         }
1607
1608         ret = -ENOMEM;
1609         scb = kcalloc(2, sizeof(struct afs_status_cb), GFP_KERNEL);
1610         if (!scb)
1611                 goto error_scb;
1612
1613         ret = -ERESTARTSYS;
1614         if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
1615                 data_version = dvnode->status.data_version + 1;
1616
1617                 while (afs_select_fileserver(&fc)) {
1618                         fc.cb_break = afs_calc_vnode_cb_break(dvnode);
1619                         afs_prep_for_new_inode(&fc, &iget_data);
1620                         afs_fs_create(&fc, dentry->d_name.name, mode,
1621                                       &scb[0], &iget_data.fid, &scb[1]);
1622                 }
1623
1624                 afs_check_for_remote_deletion(&fc, dvnode);
1625                 afs_vnode_commit_status(&fc, dvnode, fc.cb_break,
1626                                         &data_version, &scb[0]);
1627                 afs_update_dentry_version(&fc, dentry, &scb[0]);
1628                 afs_vnode_new_inode(&fc, dentry, &iget_data, &scb[1]);
1629                 ret = afs_end_vnode_operation(&fc);
1630                 if (ret < 0)
1631                         goto error_key;
1632         } else {
1633                 goto error_key;
1634         }
1635
1636         down_write(&dvnode->validate_lock);
1637         if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags) &&
1638             dvnode->status.data_version == data_version)
1639                 afs_edit_dir_add(dvnode, &dentry->d_name, &iget_data.fid,
1640                                  afs_edit_dir_for_create);
1641         up_write(&dvnode->validate_lock);
1642
1643         kfree(scb);
1644         key_put(key);
1645         _leave(" = 0");
1646         return 0;
1647
1648 error_scb:
1649         kfree(scb);
1650 error_key:
1651         key_put(key);
1652 error:
1653         d_drop(dentry);
1654         _leave(" = %d", ret);
1655         return ret;
1656 }
1657
1658 /*
1659  * create a hard link between files in an AFS filesystem
1660  */
1661 static int afs_link(struct dentry *from, struct inode *dir,
1662                     struct dentry *dentry)
1663 {
1664         struct afs_fs_cursor fc;
1665         struct afs_status_cb *scb;
1666         struct afs_vnode *dvnode = AFS_FS_I(dir);
1667         struct afs_vnode *vnode = AFS_FS_I(d_inode(from));
1668         struct key *key;
1669         afs_dataversion_t data_version;
1670         int ret;
1671
1672         _enter("{%llx:%llu},{%llx:%llu},{%pd}",
1673                vnode->fid.vid, vnode->fid.vnode,
1674                dvnode->fid.vid, dvnode->fid.vnode,
1675                dentry);
1676
1677         ret = -ENAMETOOLONG;
1678         if (dentry->d_name.len >= AFSNAMEMAX)
1679                 goto error;
1680
1681         ret = -ENOMEM;
1682         scb = kcalloc(2, sizeof(struct afs_status_cb), GFP_KERNEL);
1683         if (!scb)
1684                 goto error;
1685
1686         key = afs_request_key(dvnode->volume->cell);
1687         if (IS_ERR(key)) {
1688                 ret = PTR_ERR(key);
1689                 goto error_scb;
1690         }
1691
1692         ret = -ERESTARTSYS;
1693         if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
1694                 data_version = dvnode->status.data_version + 1;
1695
1696                 if (mutex_lock_interruptible_nested(&vnode->io_lock, 1) < 0) {
1697                         afs_end_vnode_operation(&fc);
1698                         goto error_key;
1699                 }
1700
1701                 while (afs_select_fileserver(&fc)) {
1702                         fc.cb_break = afs_calc_vnode_cb_break(dvnode);
1703                         fc.cb_break_2 = afs_calc_vnode_cb_break(vnode);
1704                         afs_fs_link(&fc, vnode, dentry->d_name.name,
1705                                     &scb[0], &scb[1]);
1706                 }
1707
1708                 afs_vnode_commit_status(&fc, dvnode, fc.cb_break,
1709                                         &data_version, &scb[0]);
1710                 afs_vnode_commit_status(&fc, vnode, fc.cb_break_2,
1711                                         NULL, &scb[1]);
1712                 ihold(&vnode->vfs_inode);
1713                 afs_update_dentry_version(&fc, dentry, &scb[0]);
1714                 d_instantiate(dentry, &vnode->vfs_inode);
1715
1716                 mutex_unlock(&vnode->io_lock);
1717                 ret = afs_end_vnode_operation(&fc);
1718                 if (ret < 0)
1719                         goto error_key;
1720         } else {
1721                 goto error_key;
1722         }
1723
1724         down_write(&dvnode->validate_lock);
1725         if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags) &&
1726             dvnode->status.data_version == data_version)
1727                 afs_edit_dir_add(dvnode, &dentry->d_name, &vnode->fid,
1728                                  afs_edit_dir_for_link);
1729         up_write(&dvnode->validate_lock);
1730
1731         key_put(key);
1732         kfree(scb);
1733         _leave(" = 0");
1734         return 0;
1735
1736 error_key:
1737         key_put(key);
1738 error_scb:
1739         kfree(scb);
1740 error:
1741         d_drop(dentry);
1742         _leave(" = %d", ret);
1743         return ret;
1744 }
1745
1746 /*
1747  * create a symlink in an AFS filesystem
1748  */
1749 static int afs_symlink(struct inode *dir, struct dentry *dentry,
1750                        const char *content)
1751 {
1752         struct afs_iget_data iget_data;
1753         struct afs_fs_cursor fc;
1754         struct afs_status_cb *scb;
1755         struct afs_vnode *dvnode = AFS_FS_I(dir);
1756         struct key *key;
1757         afs_dataversion_t data_version;
1758         int ret;
1759
1760         _enter("{%llx:%llu},{%pd},%s",
1761                dvnode->fid.vid, dvnode->fid.vnode, dentry,
1762                content);
1763
1764         ret = -ENAMETOOLONG;
1765         if (dentry->d_name.len >= AFSNAMEMAX)
1766                 goto error;
1767
1768         ret = -EINVAL;
1769         if (strlen(content) >= AFSPATHMAX)
1770                 goto error;
1771
1772         ret = -ENOMEM;
1773         scb = kcalloc(2, sizeof(struct afs_status_cb), GFP_KERNEL);
1774         if (!scb)
1775                 goto error;
1776
1777         key = afs_request_key(dvnode->volume->cell);
1778         if (IS_ERR(key)) {
1779                 ret = PTR_ERR(key);
1780                 goto error_scb;
1781         }
1782
1783         ret = -ERESTARTSYS;
1784         if (afs_begin_vnode_operation(&fc, dvnode, key, true)) {
1785                 data_version = dvnode->status.data_version + 1;
1786
1787                 while (afs_select_fileserver(&fc)) {
1788                         fc.cb_break = afs_calc_vnode_cb_break(dvnode);
1789                         afs_prep_for_new_inode(&fc, &iget_data);
1790                         afs_fs_symlink(&fc, dentry->d_name.name, content,
1791                                        &scb[0], &iget_data.fid, &scb[1]);
1792                 }
1793
1794                 afs_check_for_remote_deletion(&fc, dvnode);
1795                 afs_vnode_commit_status(&fc, dvnode, fc.cb_break,
1796                                         &data_version, &scb[0]);
1797                 afs_update_dentry_version(&fc, dentry, &scb[0]);
1798                 afs_vnode_new_inode(&fc, dentry, &iget_data, &scb[1]);
1799                 ret = afs_end_vnode_operation(&fc);
1800                 if (ret < 0)
1801                         goto error_key;
1802         } else {
1803                 goto error_key;
1804         }
1805
1806         down_write(&dvnode->validate_lock);
1807         if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags) &&
1808             dvnode->status.data_version == data_version)
1809                 afs_edit_dir_add(dvnode, &dentry->d_name, &iget_data.fid,
1810                                  afs_edit_dir_for_symlink);
1811         up_write(&dvnode->validate_lock);
1812
1813         key_put(key);
1814         kfree(scb);
1815         _leave(" = 0");
1816         return 0;
1817
1818 error_key:
1819         key_put(key);
1820 error_scb:
1821         kfree(scb);
1822 error:
1823         d_drop(dentry);
1824         _leave(" = %d", ret);
1825         return ret;
1826 }
1827
1828 /*
1829  * rename a file in an AFS filesystem and/or move it between directories
1830  */
1831 static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
1832                       struct inode *new_dir, struct dentry *new_dentry,
1833                       unsigned int flags)
1834 {
1835         struct afs_fs_cursor fc;
1836         struct afs_status_cb *scb;
1837         struct afs_vnode *orig_dvnode, *new_dvnode, *vnode;
1838         struct dentry *tmp = NULL, *rehash = NULL;
1839         struct inode *new_inode;
1840         struct key *key;
1841         afs_dataversion_t orig_data_version;
1842         afs_dataversion_t new_data_version;
1843         bool new_negative = d_is_negative(new_dentry);
1844         int ret;
1845
1846         if (flags)
1847                 return -EINVAL;
1848
1849         /* Don't allow silly-rename files be moved around. */
1850         if (old_dentry->d_flags & DCACHE_NFSFS_RENAMED)
1851                 return -EINVAL;
1852
1853         vnode = AFS_FS_I(d_inode(old_dentry));
1854         orig_dvnode = AFS_FS_I(old_dir);
1855         new_dvnode = AFS_FS_I(new_dir);
1856
1857         _enter("{%llx:%llu},{%llx:%llu},{%llx:%llu},{%pd}",
1858                orig_dvnode->fid.vid, orig_dvnode->fid.vnode,
1859                vnode->fid.vid, vnode->fid.vnode,
1860                new_dvnode->fid.vid, new_dvnode->fid.vnode,
1861                new_dentry);
1862
1863         ret = -ENOMEM;
1864         scb = kcalloc(2, sizeof(struct afs_status_cb), GFP_KERNEL);
1865         if (!scb)
1866                 goto error;
1867
1868         key = afs_request_key(orig_dvnode->volume->cell);
1869         if (IS_ERR(key)) {
1870                 ret = PTR_ERR(key);
1871                 goto error_scb;
1872         }
1873
1874         /* For non-directories, check whether the target is busy and if so,
1875          * make a copy of the dentry and then do a silly-rename.  If the
1876          * silly-rename succeeds, the copied dentry is hashed and becomes the
1877          * new target.
1878          */
1879         if (d_is_positive(new_dentry) && !d_is_dir(new_dentry)) {
1880                 /* To prevent any new references to the target during the
1881                  * rename, we unhash the dentry in advance.
1882                  */
1883                 if (!d_unhashed(new_dentry)) {
1884                         d_drop(new_dentry);
1885                         rehash = new_dentry;
1886                 }
1887
1888                 if (d_count(new_dentry) > 2) {
1889                         /* copy the target dentry's name */
1890                         ret = -ENOMEM;
1891                         tmp = d_alloc(new_dentry->d_parent,
1892                                       &new_dentry->d_name);
1893                         if (!tmp)
1894                                 goto error_rehash;
1895
1896                         ret = afs_sillyrename(new_dvnode,
1897                                               AFS_FS_I(d_inode(new_dentry)),
1898                                               new_dentry, key);
1899                         if (ret)
1900                                 goto error_rehash;
1901
1902                         new_dentry = tmp;
1903                         rehash = NULL;
1904                         new_negative = true;
1905                 }
1906         }
1907
1908         /* This bit is potentially nasty as there's a potential race with
1909          * afs_d_revalidate{,_rcu}().  We have to change d_fsdata on the dentry
1910          * to reflect it's new parent's new data_version after the op, but
1911          * d_revalidate may see old_dentry between the op having taken place
1912          * and the version being updated.
1913          *
1914          * So drop the old_dentry for now to make other threads go through
1915          * lookup instead - which we hold a lock against.
1916          */
1917         d_drop(old_dentry);
1918
1919         ret = -ERESTARTSYS;
1920         if (afs_begin_vnode_operation(&fc, orig_dvnode, key, true)) {
1921                 orig_data_version = orig_dvnode->status.data_version + 1;
1922
1923                 if (orig_dvnode != new_dvnode) {
1924                         if (mutex_lock_interruptible_nested(&new_dvnode->io_lock, 1) < 0) {
1925                                 afs_end_vnode_operation(&fc);
1926                                 goto error_rehash_old;
1927                         }
1928                         new_data_version = new_dvnode->status.data_version + 1;
1929                 } else {
1930                         new_data_version = orig_data_version;
1931                 }
1932
1933                 while (afs_select_fileserver(&fc)) {
1934                         fc.cb_break = afs_calc_vnode_cb_break(orig_dvnode);
1935                         fc.cb_break_2 = afs_calc_vnode_cb_break(new_dvnode);
1936                         afs_fs_rename(&fc, old_dentry->d_name.name,
1937                                       new_dvnode, new_dentry->d_name.name,
1938                                       &scb[0], &scb[1]);
1939                 }
1940
1941                 afs_vnode_commit_status(&fc, orig_dvnode, fc.cb_break,
1942                                         &orig_data_version, &scb[0]);
1943                 if (new_dvnode != orig_dvnode) {
1944                         afs_vnode_commit_status(&fc, new_dvnode, fc.cb_break_2,
1945                                                 &new_data_version, &scb[1]);
1946                         mutex_unlock(&new_dvnode->io_lock);
1947                 }
1948                 ret = afs_end_vnode_operation(&fc);
1949                 if (ret < 0)
1950                         goto error_rehash_old;
1951         }
1952
1953         if (ret == 0) {
1954                 if (rehash)
1955                         d_rehash(rehash);
1956                 down_write(&orig_dvnode->validate_lock);
1957                 if (test_bit(AFS_VNODE_DIR_VALID, &orig_dvnode->flags) &&
1958                     orig_dvnode->status.data_version == orig_data_version)
1959                         afs_edit_dir_remove(orig_dvnode, &old_dentry->d_name,
1960                                             afs_edit_dir_for_rename_0);
1961                 if (orig_dvnode != new_dvnode) {
1962                         up_write(&orig_dvnode->validate_lock);
1963
1964                         down_write(&new_dvnode->validate_lock);
1965                 }
1966                 if (test_bit(AFS_VNODE_DIR_VALID, &new_dvnode->flags) &&
1967                     orig_dvnode->status.data_version == new_data_version) {
1968                         if (!new_negative)
1969                                 afs_edit_dir_remove(new_dvnode, &new_dentry->d_name,
1970                                                     afs_edit_dir_for_rename_1);
1971
1972                         afs_edit_dir_add(new_dvnode, &new_dentry->d_name,
1973                                          &vnode->fid, afs_edit_dir_for_rename_2);
1974                 }
1975
1976                 new_inode = d_inode(new_dentry);
1977                 if (new_inode) {
1978                         spin_lock(&new_inode->i_lock);
1979                         if (new_inode->i_nlink > 0)
1980                                 drop_nlink(new_inode);
1981                         spin_unlock(&new_inode->i_lock);
1982                 }
1983
1984                 /* Now we can update d_fsdata on the dentries to reflect their
1985                  * new parent's data_version.
1986                  *
1987                  * Note that if we ever implement RENAME_EXCHANGE, we'll have
1988                  * to update both dentries with opposing dir versions.
1989                  */
1990                 afs_update_dentry_version(&fc, old_dentry, &scb[1]);
1991                 afs_update_dentry_version(&fc, new_dentry, &scb[1]);
1992                 d_move(old_dentry, new_dentry);
1993                 up_write(&new_dvnode->validate_lock);
1994                 goto error_tmp;
1995         }
1996
1997 error_rehash_old:
1998         d_rehash(new_dentry);
1999 error_rehash:
2000         if (rehash)
2001                 d_rehash(rehash);
2002 error_tmp:
2003         if (tmp)
2004                 dput(tmp);
2005         key_put(key);
2006 error_scb:
2007         kfree(scb);
2008 error:
2009         _leave(" = %d", ret);
2010         return ret;
2011 }
2012
2013 /*
2014  * Release a directory page and clean up its private state if it's not busy
2015  * - return true if the page can now be released, false if not
2016  */
2017 static int afs_dir_releasepage(struct page *page, gfp_t gfp_flags)
2018 {
2019         struct afs_vnode *dvnode = AFS_FS_I(page->mapping->host);
2020
2021         _enter("{{%llx:%llu}[%lu]}", dvnode->fid.vid, dvnode->fid.vnode, page->index);
2022
2023         set_page_private(page, 0);
2024         ClearPagePrivate(page);
2025
2026         /* The directory will need reloading. */
2027         if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
2028                 afs_stat_v(dvnode, n_relpg);
2029         return 1;
2030 }
2031
2032 /*
2033  * invalidate part or all of a page
2034  * - release a page and clean up its private data if offset is 0 (indicating
2035  *   the entire page)
2036  */
2037 static void afs_dir_invalidatepage(struct page *page, unsigned int offset,
2038                                    unsigned int length)
2039 {
2040         struct afs_vnode *dvnode = AFS_FS_I(page->mapping->host);
2041
2042         _enter("{%lu},%u,%u", page->index, offset, length);
2043
2044         BUG_ON(!PageLocked(page));
2045
2046         /* The directory will need reloading. */
2047         if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
2048                 afs_stat_v(dvnode, n_inval);
2049
2050         /* we clean up only if the entire page is being invalidated */
2051         if (offset == 0 && length == PAGE_SIZE) {
2052                 set_page_private(page, 0);
2053                 ClearPagePrivate(page);
2054         }
2055 }