fs/ceph/dir.c

   1 #include <linux/ceph/ceph_debug.h>
   2
   3 #include <linux/spinlock.h>
   4 #include <linux/fs_struct.h>
   5 #include <linux/namei.h>
   6 #include <linux/slab.h>
   7 #include <linux/sched.h>
   8 #include <linux/xattr.h>
   9
  10 #include "super.h"
  11 #include "mds_client.h"
  12
  13 /*
  14  * Directory operations: readdir, lookup, create, link, unlink,
  15  * rename, etc.
  16  */
  17
  18 /*
  19  * Ceph MDS operations are specified in terms of a base ino and
  20  * relative path.  Thus, the client can specify an operation on a
  21  * specific inode (e.g., a getattr due to fstat(2)), or as a path
  22  * relative to, say, the root directory.
  23  *
  24  * Normally, we limit ourselves to strict inode ops (no path component)
  25  * or dentry operations (a single path component relative to an ino).  The
  26  * exception to this is open_root_dentry(), which will open the mount
  27  * point by name.
  28  */
  29
  30 const struct dentry_operations ceph_dentry_ops;
  31
  32 /*
  33  * Initialize ceph dentry state.
  34  */
  35 int ceph_init_dentry(struct dentry *dentry)
  36 {
  37         struct ceph_dentry_info *di;
  38
  39         if (dentry->d_fsdata)
  40                 return 0;
  41
  42         di = kmem_cache_zalloc(ceph_dentry_cachep, GFP_KERNEL);
  43         if (!di)
  44                 return -ENOMEM;          /* oh well */
  45
  46         spin_lock(&dentry->d_lock);
  47         if (dentry->d_fsdata) {
  48                 /* lost a race */
  49                 kmem_cache_free(ceph_dentry_cachep, di);
  50                 goto out_unlock;
  51         }
  52
  53         if (ceph_snap(d_inode(dentry->d_parent)) == CEPH_NOSNAP)
  54                 d_set_d_op(dentry, &ceph_dentry_ops);
  55         else if (ceph_snap(d_inode(dentry->d_parent)) == CEPH_SNAPDIR)
  56                 d_set_d_op(dentry, &ceph_snapdir_dentry_ops);
  57         else
  58                 d_set_d_op(dentry, &ceph_snap_dentry_ops);
  59
  60         di->dentry = dentry;
  61         di->lease_session = NULL;
  62         dentry->d_time = jiffies;
  63         /* avoid reordering d_fsdata setup so that the check above is safe */
  64         smp_mb();
  65         dentry->d_fsdata = di;
  66         ceph_dentry_lru_add(dentry);
  67 out_unlock:
  68         spin_unlock(&dentry->d_lock);
  69         return 0;
  70 }
  71
  72 /*
  73  * for readdir, we encode the directory frag and offset within that
  74  * frag into f_pos.
  75  */
  76 static unsigned fpos_frag(loff_t p)
  77 {
  78         return p >> 32;
  79 }
  80 static unsigned fpos_off(loff_t p)
  81 {
  82         return p & 0xffffffff;
  83 }
  84
  85 static int fpos_cmp(loff_t l, loff_t r)
  86 {
  87         int v = ceph_frag_compare(fpos_frag(l), fpos_frag(r));
  88         if (v)
  89                 return v;
  90         return (int)(fpos_off(l) - fpos_off(r));
  91 }
  92
  93 /*
  94  * make note of the last dentry we read, so we can
  95  * continue at the same lexicographical point,
  96  * regardless of what dir changes take place on the
  97  * server.
  98  */
  99 static int note_last_dentry(struct ceph_file_info *fi, const char *name,
 100                             int len, unsigned next_offset)
 101 {
 102         char *buf = kmalloc(len+1, GFP_KERNEL);
 103         if (!buf)
 104                 return -ENOMEM;
 105         kfree(fi->last_name);
 106         fi->last_name = buf;
 107         memcpy(fi->last_name, name, len);
 108         fi->last_name[len] = 0;
 109         fi->next_offset = next_offset;
 110         dout("note_last_dentry '%s'\n", fi->last_name);
 111         return 0;
 112 }
 113
 114 /*
 115  * When possible, we try to satisfy a readdir by peeking at the
 116  * dcache.  We make this work by carefully ordering dentries on
 117  * d_child when we initially get results back from the MDS, and
 118  * falling back to a "normal" sync readdir if any dentries in the dir
 119  * are dropped.
 120  *
 121  * Complete dir indicates that we have all dentries in the dir.  It is
 122  * defined IFF we hold CEPH_CAP_FILE_SHARED (which will be revoked by
 123  * the MDS if/when the directory is modified).
 124  */
 125 static int __dcache_readdir(struct file *file,  struct dir_context *ctx,
 126                             u32 shared_gen)
 127 {
 128         struct ceph_file_info *fi = file->private_data;
 129         struct dentry *parent = file->f_path.dentry;
 130         struct inode *dir = d_inode(parent);
 131         struct dentry *dentry, *last = NULL;
 132         struct ceph_dentry_info *di;
 133         unsigned nsize = PAGE_SIZE / sizeof(struct dentry *);
 134         int err = 0;
 135         loff_t ptr_pos = 0;
 136         struct ceph_readdir_cache_control cache_ctl = {};
 137
 138         dout("__dcache_readdir %p v%u at %llu\n", dir, shared_gen, ctx->pos);
 139
 140         /* we can calculate cache index for the first dirfrag */
 141         if (ceph_frag_is_leftmost(fpos_frag(ctx->pos))) {
 142                 cache_ctl.index = fpos_off(ctx->pos) - 2;
 143                 BUG_ON(cache_ctl.index < 0);
 144                 ptr_pos = cache_ctl.index * sizeof(struct dentry *);
 145         }
 146
 147         while (true) {
 148                 pgoff_t pgoff;
 149                 bool emit_dentry;
 150
 151                 if (ptr_pos >= i_size_read(dir)) {
 152                         fi->flags |= CEPH_F_ATEND;
 153                         err = 0;
 154                         break;
 155                 }
 156
 157                 err = -EAGAIN;
 158                 pgoff = ptr_pos >> PAGE_SHIFT;
 159                 if (!cache_ctl.page || pgoff != page_index(cache_ctl.page)) {
 160                         ceph_readdir_cache_release(&cache_ctl);
 161                         cache_ctl.page = find_lock_page(&dir->i_data, pgoff);
 162                         if (!cache_ctl.page) {
 163                                 dout(" page %lu not found\n", pgoff);
 164                                 break;
 165                         }
 166                         /* reading/filling the cache are serialized by
 167                          * i_mutex, no need to use page lock */
 168                         unlock_page(cache_ctl.page);
 169                         cache_ctl.dentries = kmap(cache_ctl.page);
 170                 }
 171
 172                 rcu_read_lock();
 173                 spin_lock(&parent->d_lock);
 174                 /* check i_size again here, because empty directory can be
 175                  * marked as complete while not holding the i_mutex. */
 176                 if (ceph_dir_is_complete_ordered(dir) &&
 177                     ptr_pos < i_size_read(dir))
 178                         dentry = cache_ctl.dentries[cache_ctl.index % nsize];
 179                 else
 180                         dentry = NULL;
 181                 spin_unlock(&parent->d_lock);
 182                 if (dentry && !lockref_get_not_dead(&dentry->d_lockref))
 183                         dentry = NULL;
 184                 rcu_read_unlock();
 185                 if (!dentry)
 186                         break;
 187
 188                 emit_dentry = false;
 189                 di = ceph_dentry(dentry);
 190                 spin_lock(&dentry->d_lock);
 191                 if (di->lease_shared_gen == shared_gen &&
 192                     d_really_is_positive(dentry) &&
 193                     ceph_snap(d_inode(dentry)) != CEPH_SNAPDIR &&
 194                     ceph_ino(d_inode(dentry)) != CEPH_INO_CEPH &&
 195                     fpos_cmp(ctx->pos, di->offset) <= 0) {
 196                         emit_dentry = true;
 197                 }
 198                 spin_unlock(&dentry->d_lock);
 199
 200                 if (emit_dentry) {
 201                         dout(" %llu (%llu) dentry %p %pd %p\n", di->offset, ctx->pos,
 202                              dentry, dentry, d_inode(dentry));
 203                         ctx->pos = di->offset;
 204                         if (!dir_emit(ctx, dentry->d_name.name,
 205                                       dentry->d_name.len,
 206                                       ceph_translate_ino(dentry->d_sb,
 207                                                          d_inode(dentry)->i_ino),
 208                                       d_inode(dentry)->i_mode >> 12)) {
 209                                 dput(dentry);
 210                                 err = 0;
 211                                 break;
 212                         }
 213                         ctx->pos++;
 214
 215                         if (last)
 216                                 dput(last);
 217                         last = dentry;
 218                 } else {
 219                         dput(dentry);
 220                 }
 221
 222                 cache_ctl.index++;
 223                 ptr_pos += sizeof(struct dentry *);
 224         }
 225         ceph_readdir_cache_release(&cache_ctl);
 226         if (last) {
 227                 int ret;
 228                 di = ceph_dentry(last);
 229                 ret = note_last_dentry(fi, last->d_name.name, last->d_name.len,
 230                                        fpos_off(di->offset) + 1);
 231                 if (ret < 0)
 232                         err = ret;
 233                 dput(last);
 234         }
 235         return err;
 236 }
 237
 238 static int ceph_readdir(struct file *file, struct dir_context *ctx)
 239 {
 240         struct ceph_file_info *fi = file->private_data;
 241         struct inode *inode = file_inode(file);
 242         struct ceph_inode_info *ci = ceph_inode(inode);
 243         struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 244         struct ceph_mds_client *mdsc = fsc->mdsc;
 245         unsigned frag = fpos_frag(ctx->pos);
 246         int off = fpos_off(ctx->pos);
 247         int err;
 248         u32 ftype;
 249         struct ceph_mds_reply_info_parsed *rinfo;
 250
 251         dout("readdir %p file %p frag %u off %u\n", inode, file, frag, off);
 252         if (fi->flags & CEPH_F_ATEND)
 253                 return 0;
 254
 255         /* always start with . and .. */
 256         if (ctx->pos == 0) {
 257                 dout("readdir off 0 -> '.'\n");
 258                 if (!dir_emit(ctx, ".", 1,
 259                             ceph_translate_ino(inode->i_sb, inode->i_ino),
 260                             inode->i_mode >> 12))
 261                         return 0;
 262                 ctx->pos = 1;
 263                 off = 1;
 264         }
 265         if (ctx->pos == 1) {
 266                 ino_t ino = parent_ino(file->f_path.dentry);
 267                 dout("readdir off 1 -> '..'\n");
 268                 if (!dir_emit(ctx, "..", 2,
 269                             ceph_translate_ino(inode->i_sb, ino),
 270                             inode->i_mode >> 12))
 271                         return 0;
 272                 ctx->pos = 2;
 273                 off = 2;
 274         }
 275
 276         /* can we use the dcache? */
 277         spin_lock(&ci->i_ceph_lock);
 278         if (ceph_test_mount_opt(fsc, DCACHE) &&
 279             !ceph_test_mount_opt(fsc, NOASYNCREADDIR) &&
 280             ceph_snap(inode) != CEPH_SNAPDIR &&
 281             __ceph_dir_is_complete_ordered(ci) &&
 282             __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1)) {
 283                 u32 shared_gen = ci->i_shared_gen;
 284                 spin_unlock(&ci->i_ceph_lock);
 285                 err = __dcache_readdir(file, ctx, shared_gen);
 286                 if (err != -EAGAIN)
 287                         return err;
 288                 frag = fpos_frag(ctx->pos);
 289                 off = fpos_off(ctx->pos);
 290         } else {
 291                 spin_unlock(&ci->i_ceph_lock);
 292         }
 293
 294         /* proceed with a normal readdir */
 295 more:
 296         /* do we have the correct frag content buffered? */
 297         if (fi->frag != frag || fi->last_readdir == NULL) {
 298                 struct ceph_mds_request *req;
 299                 int op = ceph_snap(inode) == CEPH_SNAPDIR ?
 300                         CEPH_MDS_OP_LSSNAP : CEPH_MDS_OP_READDIR;
 301
 302                 /* discard old result, if any */
 303                 if (fi->last_readdir) {
 304                         ceph_mdsc_put_request(fi->last_readdir);
 305                         fi->last_readdir = NULL;
 306                 }
 307
 308                 dout("readdir fetching %llx.%llx frag %x offset '%s'\n",
 309                      ceph_vinop(inode), frag, fi->last_name);
 310                 req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
 311                 if (IS_ERR(req))
 312                         return PTR_ERR(req);
 313                 err = ceph_alloc_readdir_reply_buffer(req, inode);
 314                 if (err) {
 315                         ceph_mdsc_put_request(req);
 316                         return err;
 317                 }
 318                 /* hints to request -> mds selection code */
 319                 req->r_direct_mode = USE_AUTH_MDS;
 320                 req->r_direct_hash = ceph_frag_value(frag);
 321                 req->r_direct_is_hash = true;
 322                 if (fi->last_name) {
 323                         req->r_path2 = kstrdup(fi->last_name, GFP_KERNEL);
 324                         if (!req->r_path2) {
 325                                 ceph_mdsc_put_request(req);
 326                                 return -ENOMEM;
 327                         }
 328                 }
 329                 req->r_dir_release_cnt = fi->dir_release_count;
 330                 req->r_dir_ordered_cnt = fi->dir_ordered_count;
 331                 req->r_readdir_cache_idx = fi->readdir_cache_idx;
 332                 req->r_readdir_offset = fi->next_offset;
 333                 req->r_args.readdir.frag = cpu_to_le32(frag);
 334
 335                 req->r_inode = inode;
 336                 ihold(inode);
 337                 req->r_dentry = dget(file->f_path.dentry);
 338                 err = ceph_mdsc_do_request(mdsc, NULL, req);
 339                 if (err < 0) {
 340                         ceph_mdsc_put_request(req);
 341                         return err;
 342                 }
 343                 dout("readdir got and parsed readdir result=%d"
 344                      " on frag %x, end=%d, complete=%d\n", err, frag,
 345                      (int)req->r_reply_info.dir_end,
 346                      (int)req->r_reply_info.dir_complete);
 347
 348
 349                 /* note next offset and last dentry name */
 350                 rinfo = &req->r_reply_info;
 351                 if (le32_to_cpu(rinfo->dir_dir->frag) != frag) {
 352                         frag = le32_to_cpu(rinfo->dir_dir->frag);
 353                         off = req->r_readdir_offset;
 354                         fi->next_offset = off;
 355                 }
 356
 357                 fi->frag = frag;
 358                 fi->offset = fi->next_offset;
 359                 fi->last_readdir = req;
 360
 361                 if (req->r_did_prepopulate) {
 362                         fi->readdir_cache_idx = req->r_readdir_cache_idx;
 363                         if (fi->readdir_cache_idx < 0) {
 364                                 /* preclude from marking dir ordered */
 365                                 fi->dir_ordered_count = 0;
 366                         } else if (ceph_frag_is_leftmost(frag) && off == 2) {
 367                                 /* note dir version at start of readdir so
 368                                  * we can tell if any dentries get dropped */
 369                                 fi->dir_release_count = req->r_dir_release_cnt;
 370                                 fi->dir_ordered_count = req->r_dir_ordered_cnt;
 371                         }
 372                 } else {
 373                         dout("readdir !did_prepopulate");
 374                         /* disable readdir cache */
 375                         fi->readdir_cache_idx = -1;
 376                         /* preclude from marking dir complete */
 377                         fi->dir_release_count = 0;
 378                 }
 379
 380                 if (req->r_reply_info.dir_end) {
 381                         kfree(fi->last_name);
 382                         fi->last_name = NULL;
 383                         if (ceph_frag_is_rightmost(frag))
 384                                 fi->next_offset = 2;
 385                         else
 386                                 fi->next_offset = 0;
 387                 } else {
 388                         err = note_last_dentry(fi,
 389                                        rinfo->dir_dname[rinfo->dir_nr-1],
 390                                        rinfo->dir_dname_len[rinfo->dir_nr-1],
 391                                        fi->next_offset + rinfo->dir_nr);
 392                         if (err)
 393                                 return err;
 394                 }
 395         }
 396
 397         rinfo = &fi->last_readdir->r_reply_info;
 398         dout("readdir frag %x num %d off %d chunkoff %d\n", frag,
 399              rinfo->dir_nr, off, fi->offset);
 400
 401         ctx->pos = ceph_make_fpos(frag, off);
 402         while (off >= fi->offset && off - fi->offset < rinfo->dir_nr) {
 403                 struct ceph_mds_reply_inode *in =
 404                         rinfo->dir_in[off - fi->offset].in;
 405                 struct ceph_vino vino;
 406                 ino_t ino;
 407
 408                 dout("readdir off %d (%d/%d) -> %lld '%.*s' %p\n",
 409                      off, off - fi->offset, rinfo->dir_nr, ctx->pos,
 410                      rinfo->dir_dname_len[off - fi->offset],
 411                      rinfo->dir_dname[off - fi->offset], in);
 412                 BUG_ON(!in);
 413                 ftype = le32_to_cpu(in->mode) >> 12;
 414                 vino.ino = le64_to_cpu(in->ino);
 415                 vino.snap = le64_to_cpu(in->snapid);
 416                 ino = ceph_vino_to_ino(vino);
 417                 if (!dir_emit(ctx,
 418                             rinfo->dir_dname[off - fi->offset],
 419                             rinfo->dir_dname_len[off - fi->offset],
 420                             ceph_translate_ino(inode->i_sb, ino), ftype)) {
 421                         dout("filldir stopping us...\n");
 422                         return 0;
 423                 }
 424                 off++;
 425                 ctx->pos++;
 426         }
 427
 428         if (fi->last_name) {
 429                 ceph_mdsc_put_request(fi->last_readdir);
 430                 fi->last_readdir = NULL;
 431                 goto more;
 432         }
 433
 434         /* more frags? */
 435         if (!ceph_frag_is_rightmost(frag)) {
 436                 frag = ceph_frag_next(frag);
 437                 off = 0;
 438                 ctx->pos = ceph_make_fpos(frag, off);
 439                 dout("readdir next frag is %x\n", frag);
 440                 goto more;
 441         }
 442         fi->flags |= CEPH_F_ATEND;
 443
 444         /*
 445          * if dir_release_count still matches the dir, no dentries
 446          * were released during the whole readdir, and we should have
 447          * the complete dir contents in our cache.
 448          */
 449         if (atomic64_read(&ci->i_release_count) == fi->dir_release_count) {
 450                 spin_lock(&ci->i_ceph_lock);
 451                 if (fi->dir_ordered_count == atomic64_read(&ci->i_ordered_count)) {
 452                         dout(" marking %p complete and ordered\n", inode);
 453                         /* use i_size to track number of entries in
 454                          * readdir cache */
 455                         BUG_ON(fi->readdir_cache_idx < 0);
 456                         i_size_write(inode, fi->readdir_cache_idx *
 457                                      sizeof(struct dentry*));
 458                 } else {
 459                         dout(" marking %p complete\n", inode);
 460                 }
 461                 __ceph_dir_set_complete(ci, fi->dir_release_count,
 462                                         fi->dir_ordered_count);
 463                 spin_unlock(&ci->i_ceph_lock);
 464         }
 465
 466         dout("readdir %p file %p done.\n", inode, file);
 467         return 0;
 468 }
 469
 470 static void reset_readdir(struct ceph_file_info *fi, unsigned frag)
 471 {
 472         if (fi->last_readdir) {
 473                 ceph_mdsc_put_request(fi->last_readdir);
 474                 fi->last_readdir = NULL;
 475         }
 476         kfree(fi->last_name);
 477         fi->last_name = NULL;
 478         fi->dir_release_count = 0;
 479         fi->readdir_cache_idx = -1;
 480         if (ceph_frag_is_leftmost(frag))
 481                 fi->next_offset = 2;  /* compensate for . and .. */
 482         else
 483                 fi->next_offset = 0;
 484         fi->flags &= ~CEPH_F_ATEND;
 485 }
 486
 487 static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int whence)
 488 {
 489         struct ceph_file_info *fi = file->private_data;
 490         struct inode *inode = file->f_mapping->host;
 491         loff_t old_offset = ceph_make_fpos(fi->frag, fi->next_offset);
 492         loff_t retval;
 493
 494         inode_lock(inode);
 495         retval = -EINVAL;
 496         switch (whence) {
 497         case SEEK_CUR:
 498                 offset += file->f_pos;
 499         case SEEK_SET:
 500                 break;
 501         case SEEK_END:
 502                 retval = -EOPNOTSUPP;
 503         default:
 504                 goto out;
 505         }
 506
 507         if (offset >= 0) {
 508                 if (offset != file->f_pos) {
 509                         file->f_pos = offset;
 510                         file->f_version = 0;
 511                         fi->flags &= ~CEPH_F_ATEND;
 512                 }
 513                 retval = offset;
 514
 515                 if (offset == 0 ||
 516                     fpos_frag(offset) != fi->frag ||
 517                     fpos_off(offset) < fi->offset) {
 518                         /* discard buffered readdir content on seekdir(0), or
 519                          * seek to new frag, or seek prior to current chunk */
 520                         dout("dir_llseek dropping %p content\n", file);
 521                         reset_readdir(fi, fpos_frag(offset));
 522                 } else if (fpos_cmp(offset, old_offset) > 0) {
 523                         /* reset dir_release_count if we did a forward seek */
 524                         fi->dir_release_count = 0;
 525                         fi->readdir_cache_idx = -1;
 526                 }
 527         }
 528 out:
 529         inode_unlock(inode);
 530         return retval;
 531 }
 532
 533 /*
 534  * Handle lookups for the hidden .snap directory.
 535  */
 536 int ceph_handle_snapdir(struct ceph_mds_request *req,
 537                         struct dentry *dentry, int err)
 538 {
 539         struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
 540         struct inode *parent = d_inode(dentry->d_parent); /* we hold i_mutex */
 541
 542         /* .snap dir? */
 543         if (err == -ENOENT &&
 544             ceph_snap(parent) == CEPH_NOSNAP &&
 545             strcmp(dentry->d_name.name,
 546                    fsc->mount_options->snapdir_name) == 0) {
 547                 struct inode *inode = ceph_get_snapdir(parent);
 548                 dout("ENOENT on snapdir %p '%pd', linking to snapdir %p\n",
 549                      dentry, dentry, inode);
 550                 BUG_ON(!d_unhashed(dentry));
 551                 d_add(dentry, inode);
 552                 err = 0;
 553         }
 554         return err;
 555 }
 556
 557 /*
 558  * Figure out final result of a lookup/open request.
 559  *
 560  * Mainly, make sure we return the final req->r_dentry (if it already
 561  * existed) in place of the original VFS-provided dentry when they
 562  * differ.
 563  *
 564  * Gracefully handle the case where the MDS replies with -ENOENT and
 565  * no trace (which it may do, at its discretion, e.g., if it doesn't
 566  * care to issue a lease on the negative dentry).
 567  */
 568 struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
 569                                   struct dentry *dentry, int err)
 570 {
 571         if (err == -ENOENT) {
 572                 /* no trace? */
 573                 err = 0;
 574                 if (!req->r_reply_info.head->is_dentry) {
 575                         dout("ENOENT and no trace, dentry %p inode %p\n",
 576                              dentry, d_inode(dentry));
 577                         if (d_really_is_positive(dentry)) {
 578                                 d_drop(dentry);
 579                                 err = -ENOENT;
 580                         } else {
 581                                 d_add(dentry, NULL);
 582                         }
 583                 }
 584         }
 585         if (err)
 586                 dentry = ERR_PTR(err);
 587         else if (dentry != req->r_dentry)
 588                 dentry = dget(req->r_dentry);   /* we got spliced */
 589         else
 590                 dentry = NULL;
 591         return dentry;
 592 }
 593
 594 static int is_root_ceph_dentry(struct inode *inode, struct dentry *dentry)
 595 {
 596         return ceph_ino(inode) == CEPH_INO_ROOT &&
 597                 strncmp(dentry->d_name.name, ".ceph", 5) == 0;
 598 }
 599
 600 /*
 601  * Look up a single dir entry.  If there is a lookup intent, inform
 602  * the MDS so that it gets our 'caps wanted' value in a single op.
 603  */
 604 static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
 605                                   unsigned int flags)
 606 {
 607         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 608         struct ceph_mds_client *mdsc = fsc->mdsc;
 609         struct ceph_mds_request *req;
 610         int op;
 611         int mask;
 612         int err;
 613
 614         dout("lookup %p dentry %p '%pd'\n",
 615              dir, dentry, dentry);
 616
 617         if (dentry->d_name.len > NAME_MAX)
 618                 return ERR_PTR(-ENAMETOOLONG);
 619
 620         err = ceph_init_dentry(dentry);
 621         if (err < 0)
 622                 return ERR_PTR(err);
 623
 624         /* can we conclude ENOENT locally? */
 625         if (d_really_is_negative(dentry)) {
 626                 struct ceph_inode_info *ci = ceph_inode(dir);
 627                 struct ceph_dentry_info *di = ceph_dentry(dentry);
 628
 629                 spin_lock(&ci->i_ceph_lock);
 630                 dout(" dir %p flags are %d\n", dir, ci->i_ceph_flags);
 631                 if (strncmp(dentry->d_name.name,
 632                             fsc->mount_options->snapdir_name,
 633                             dentry->d_name.len) &&
 634                     !is_root_ceph_dentry(dir, dentry) &&
 635                     ceph_test_mount_opt(fsc, DCACHE) &&
 636                     __ceph_dir_is_complete(ci) &&
 637                     (__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1))) {
 638                         spin_unlock(&ci->i_ceph_lock);
 639                         dout(" dir %p complete, -ENOENT\n", dir);
 640                         d_add(dentry, NULL);
 641                         di->lease_shared_gen = ci->i_shared_gen;
 642                         return NULL;
 643                 }
 644                 spin_unlock(&ci->i_ceph_lock);
 645         }
 646
 647         op = ceph_snap(dir) == CEPH_SNAPDIR ?
 648                 CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
 649         req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
 650         if (IS_ERR(req))
 651                 return ERR_CAST(req);
 652         req->r_dentry = dget(dentry);
 653         req->r_num_caps = 2;
 654
 655         mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
 656         if (ceph_security_xattr_wanted(dir))
 657                 mask |= CEPH_CAP_XATTR_SHARED;
 658         req->r_args.getattr.mask = cpu_to_le32(mask);
 659
 660         req->r_locked_dir = dir;
 661         err = ceph_mdsc_do_request(mdsc, NULL, req);
 662         err = ceph_handle_snapdir(req, dentry, err);
 663         dentry = ceph_finish_lookup(req, dentry, err);
 664         ceph_mdsc_put_request(req);  /* will dput(dentry) */
 665         dout("lookup result=%p\n", dentry);
 666         return dentry;
 667 }
 668
 669 /*
 670  * If we do a create but get no trace back from the MDS, follow up with
 671  * a lookup (the VFS expects us to link up the provided dentry).
 672  */
 673 int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
 674 {
 675         struct dentry *result = ceph_lookup(dir, dentry, 0);
 676
 677         if (result && !IS_ERR(result)) {
 678                 /*
 679                  * We created the item, then did a lookup, and found
 680                  * it was already linked to another inode we already
 681                  * had in our cache (and thus got spliced). To not
 682                  * confuse VFS (especially when inode is a directory),
 683                  * we don't link our dentry to that inode, return an
 684                  * error instead.
 685                  *
 686                  * This event should be rare and it happens only when
 687                  * we talk to old MDS. Recent MDS does not send traceless
 688                  * reply for request that creates new inode.
 689                  */
 690                 d_drop(result);
 691                 return -ESTALE;
 692         }
 693         return PTR_ERR(result);
 694 }
 695
 696 static int ceph_mknod(struct inode *dir, struct dentry *dentry,
 697                       umode_t mode, dev_t rdev)
 698 {
 699         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 700         struct ceph_mds_client *mdsc = fsc->mdsc;
 701         struct ceph_mds_request *req;
 702         struct ceph_acls_info acls = {};
 703         int err;
 704
 705         if (ceph_snap(dir) != CEPH_NOSNAP)
 706                 return -EROFS;
 707
 708         err = ceph_pre_init_acls(dir, &mode, &acls);
 709         if (err < 0)
 710                 return err;
 711
 712         dout("mknod in dir %p dentry %p mode 0%ho rdev %d\n",
 713              dir, dentry, mode, rdev);
 714         req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_MKNOD, USE_AUTH_MDS);
 715         if (IS_ERR(req)) {
 716                 err = PTR_ERR(req);
 717                 goto out;
 718         }
 719         req->r_dentry = dget(dentry);
 720         req->r_num_caps = 2;
 721         req->r_locked_dir = dir;
 722         req->r_args.mknod.mode = cpu_to_le32(mode);
 723         req->r_args.mknod.rdev = cpu_to_le32(rdev);
 724         req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
 725         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 726         if (acls.pagelist) {
 727                 req->r_pagelist = acls.pagelist;
 728                 acls.pagelist = NULL;
 729         }
 730         err = ceph_mdsc_do_request(mdsc, dir, req);
 731         if (!err && !req->r_reply_info.head->is_dentry)
 732                 err = ceph_handle_notrace_create(dir, dentry);
 733         ceph_mdsc_put_request(req);
 734 out:
 735         if (!err)
 736                 ceph_init_inode_acls(d_inode(dentry), &acls);
 737         else
 738                 d_drop(dentry);
 739         ceph_release_acls_info(&acls);
 740         return err;
 741 }
 742
 743 static int ceph_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 744                        bool excl)
 745 {
 746         return ceph_mknod(dir, dentry, mode, 0);
 747 }
 748
 749 static int ceph_symlink(struct inode *dir, struct dentry *dentry,
 750                             const char *dest)
 751 {
 752         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 753         struct ceph_mds_client *mdsc = fsc->mdsc;
 754         struct ceph_mds_request *req;
 755         int err;
 756
 757         if (ceph_snap(dir) != CEPH_NOSNAP)
 758                 return -EROFS;
 759
 760         dout("symlink in dir %p dentry %p to '%s'\n", dir, dentry, dest);
 761         req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SYMLINK, USE_AUTH_MDS);
 762         if (IS_ERR(req)) {
 763                 err = PTR_ERR(req);
 764                 goto out;
 765         }
 766         req->r_path2 = kstrdup(dest, GFP_KERNEL);
 767         if (!req->r_path2) {
 768                 err = -ENOMEM;
 769                 ceph_mdsc_put_request(req);
 770                 goto out;
 771         }
 772         req->r_locked_dir = dir;
 773         req->r_dentry = dget(dentry);
 774         req->r_num_caps = 2;
 775         req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
 776         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 777         err = ceph_mdsc_do_request(mdsc, dir, req);
 778         if (!err && !req->r_reply_info.head->is_dentry)
 779                 err = ceph_handle_notrace_create(dir, dentry);
 780         ceph_mdsc_put_request(req);
 781 out:
 782         if (err)
 783                 d_drop(dentry);
 784         return err;
 785 }
 786
 787 static int ceph_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 788 {
 789         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 790         struct ceph_mds_client *mdsc = fsc->mdsc;
 791         struct ceph_mds_request *req;
 792         struct ceph_acls_info acls = {};
 793         int err = -EROFS;
 794         int op;
 795
 796         if (ceph_snap(dir) == CEPH_SNAPDIR) {
 797                 /* mkdir .snap/foo is a MKSNAP */
 798                 op = CEPH_MDS_OP_MKSNAP;
 799                 dout("mksnap dir %p snap '%pd' dn %p\n", dir,
 800                      dentry, dentry);
 801         } else if (ceph_snap(dir) == CEPH_NOSNAP) {
 802                 dout("mkdir dir %p dn %p mode 0%ho\n", dir, dentry, mode);
 803                 op = CEPH_MDS_OP_MKDIR;
 804         } else {
 805                 goto out;
 806         }
 807
 808         mode |= S_IFDIR;
 809         err = ceph_pre_init_acls(dir, &mode, &acls);
 810         if (err < 0)
 811                 goto out;
 812
 813         req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
 814         if (IS_ERR(req)) {
 815                 err = PTR_ERR(req);
 816                 goto out;
 817         }
 818
 819         req->r_dentry = dget(dentry);
 820         req->r_num_caps = 2;
 821         req->r_locked_dir = dir;
 822         req->r_args.mkdir.mode = cpu_to_le32(mode);
 823         req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
 824         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 825         if (acls.pagelist) {
 826                 req->r_pagelist = acls.pagelist;
 827                 acls.pagelist = NULL;
 828         }
 829         err = ceph_mdsc_do_request(mdsc, dir, req);
 830         if (!err &&
 831             !req->r_reply_info.head->is_target &&
 832             !req->r_reply_info.head->is_dentry)
 833                 err = ceph_handle_notrace_create(dir, dentry);
 834         ceph_mdsc_put_request(req);
 835 out:
 836         if (!err)
 837                 ceph_init_inode_acls(d_inode(dentry), &acls);
 838         else
 839                 d_drop(dentry);
 840         ceph_release_acls_info(&acls);
 841         return err;
 842 }
 843
 844 static int ceph_link(struct dentry *old_dentry, struct inode *dir,
 845                      struct dentry *dentry)
 846 {
 847         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 848         struct ceph_mds_client *mdsc = fsc->mdsc;
 849         struct ceph_mds_request *req;
 850         int err;
 851
 852         if (ceph_snap(dir) != CEPH_NOSNAP)
 853                 return -EROFS;
 854
 855         dout("link in dir %p old_dentry %p dentry %p\n", dir,
 856              old_dentry, dentry);
 857         req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LINK, USE_AUTH_MDS);
 858         if (IS_ERR(req)) {
 859                 d_drop(dentry);
 860                 return PTR_ERR(req);
 861         }
 862         req->r_dentry = dget(dentry);
 863         req->r_num_caps = 2;
 864         req->r_old_dentry = dget(old_dentry);
 865         req->r_locked_dir = dir;
 866         req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
 867         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 868         /* release LINK_SHARED on source inode (mds will lock it) */
 869         req->r_old_inode_drop = CEPH_CAP_LINK_SHARED;
 870         err = ceph_mdsc_do_request(mdsc, dir, req);
 871         if (err) {
 872                 d_drop(dentry);
 873         } else if (!req->r_reply_info.head->is_dentry) {
 874                 ihold(d_inode(old_dentry));
 875                 d_instantiate(dentry, d_inode(old_dentry));
 876         }
 877         ceph_mdsc_put_request(req);
 878         return err;
 879 }
 880
 881 /*
 882  * For a soon-to-be unlinked file, drop the AUTH_RDCACHE caps.  If it
 883  * looks like the link count will hit 0, drop any other caps (other
 884  * than PIN) we don't specifically want (due to the file still being
 885  * open).
 886  */
 887 static int drop_caps_for_unlink(struct inode *inode)
 888 {
 889         struct ceph_inode_info *ci = ceph_inode(inode);
 890         int drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
 891
 892         spin_lock(&ci->i_ceph_lock);
 893         if (inode->i_nlink == 1) {
 894                 drop |= ~(__ceph_caps_wanted(ci) | CEPH_CAP_PIN);
 895                 ci->i_ceph_flags |= CEPH_I_NODELAY;
 896         }
 897         spin_unlock(&ci->i_ceph_lock);
 898         return drop;
 899 }
 900
 901 /*
 902  * rmdir and unlink are differ only by the metadata op code
 903  */
 904 static int ceph_unlink(struct inode *dir, struct dentry *dentry)
 905 {
 906         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 907         struct ceph_mds_client *mdsc = fsc->mdsc;
 908         struct inode *inode = d_inode(dentry);
 909         struct ceph_mds_request *req;
 910         int err = -EROFS;
 911         int op;
 912
 913         if (ceph_snap(dir) == CEPH_SNAPDIR) {
 914                 /* rmdir .snap/foo is RMSNAP */
 915                 dout("rmsnap dir %p '%pd' dn %p\n", dir, dentry, dentry);
 916                 op = CEPH_MDS_OP_RMSNAP;
 917         } else if (ceph_snap(dir) == CEPH_NOSNAP) {
 918                 dout("unlink/rmdir dir %p dn %p inode %p\n",
 919                      dir, dentry, inode);
 920                 op = d_is_dir(dentry) ?
 921                         CEPH_MDS_OP_RMDIR : CEPH_MDS_OP_UNLINK;
 922         } else
 923                 goto out;
 924         req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
 925         if (IS_ERR(req)) {
 926                 err = PTR_ERR(req);
 927                 goto out;
 928         }
 929         req->r_dentry = dget(dentry);
 930         req->r_num_caps = 2;
 931         req->r_locked_dir = dir;
 932         req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
 933         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 934         req->r_inode_drop = drop_caps_for_unlink(inode);
 935         err = ceph_mdsc_do_request(mdsc, dir, req);
 936         if (!err && !req->r_reply_info.head->is_dentry)
 937                 d_delete(dentry);
 938         ceph_mdsc_put_request(req);
 939 out:
 940         return err;
 941 }
 942
 943 static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
 944                        struct inode *new_dir, struct dentry *new_dentry)
 945 {
 946         struct ceph_fs_client *fsc = ceph_sb_to_client(old_dir->i_sb);
 947         struct ceph_mds_client *mdsc = fsc->mdsc;
 948         struct ceph_mds_request *req;
 949         int op = CEPH_MDS_OP_RENAME;
 950         int err;
 951
 952         if (ceph_snap(old_dir) != ceph_snap(new_dir))
 953                 return -EXDEV;
 954         if (ceph_snap(old_dir) != CEPH_NOSNAP) {
 955                 if (old_dir == new_dir && ceph_snap(old_dir) == CEPH_SNAPDIR)
 956                         op = CEPH_MDS_OP_RENAMESNAP;
 957                 else
 958                         return -EROFS;
 959         }
 960         dout("rename dir %p dentry %p to dir %p dentry %p\n",
 961              old_dir, old_dentry, new_dir, new_dentry);
 962         req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
 963         if (IS_ERR(req))
 964                 return PTR_ERR(req);
 965         ihold(old_dir);
 966         req->r_dentry = dget(new_dentry);
 967         req->r_num_caps = 2;
 968         req->r_old_dentry = dget(old_dentry);
 969         req->r_old_dentry_dir = old_dir;
 970         req->r_locked_dir = new_dir;
 971         req->r_old_dentry_drop = CEPH_CAP_FILE_SHARED;
 972         req->r_old_dentry_unless = CEPH_CAP_FILE_EXCL;
 973         req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
 974         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 975         /* release LINK_RDCACHE on source inode (mds will lock it) */
 976         req->r_old_inode_drop = CEPH_CAP_LINK_SHARED;
 977         if (d_really_is_positive(new_dentry))
 978                 req->r_inode_drop = drop_caps_for_unlink(d_inode(new_dentry));
 979         err = ceph_mdsc_do_request(mdsc, old_dir, req);
 980         if (!err && !req->r_reply_info.head->is_dentry) {
 981                 /*
 982                  * Normally d_move() is done by fill_trace (called by
 983                  * do_request, above).  If there is no trace, we need
 984                  * to do it here.
 985                  */
 986
 987                 /* d_move screws up sibling dentries' offsets */
 988                 ceph_dir_clear_complete(old_dir);
 989                 ceph_dir_clear_complete(new_dir);
 990
 991                 d_move(old_dentry, new_dentry);
 992
 993                 /* ensure target dentry is invalidated, despite
 994                    rehashing bug in vfs_rename_dir */
 995                 ceph_invalidate_dentry_lease(new_dentry);
 996         }
 997         ceph_mdsc_put_request(req);
 998         return err;
 999 }
1000
1001 /*
1002  * Ensure a dentry lease will no longer revalidate.
1003  */
1004 void ceph_invalidate_dentry_lease(struct dentry *dentry)
1005 {
1006         spin_lock(&dentry->d_lock);
1007         dentry->d_time = jiffies;
1008         ceph_dentry(dentry)->lease_shared_gen = 0;
1009         spin_unlock(&dentry->d_lock);
1010 }
1011
1012 /*
1013  * Check if dentry lease is valid.  If not, delete the lease.  Try to
1014  * renew if the least is more than half up.
1015  */
1016 static int dentry_lease_is_valid(struct dentry *dentry)
1017 {
1018         struct ceph_dentry_info *di;
1019         struct ceph_mds_session *s;
1020         int valid = 0;
1021         u32 gen;
1022         unsigned long ttl;
1023         struct ceph_mds_session *session = NULL;
1024         struct inode *dir = NULL;
1025         u32 seq = 0;
1026
1027         spin_lock(&dentry->d_lock);
1028         di = ceph_dentry(dentry);
1029         if (di->lease_session) {
1030                 s = di->lease_session;
1031                 spin_lock(&s->s_gen_ttl_lock);
1032                 gen = s->s_cap_gen;
1033                 ttl = s->s_cap_ttl;
1034                 spin_unlock(&s->s_gen_ttl_lock);
1035
1036                 if (di->lease_gen == gen &&
1037                     time_before(jiffies, dentry->d_time) &&
1038                     time_before(jiffies, ttl)) {
1039                         valid = 1;
1040                         if (di->lease_renew_after &&
1041                             time_after(jiffies, di->lease_renew_after)) {
1042                                 /* we should renew */
1043                                 dir = d_inode(dentry->d_parent);
1044                                 session = ceph_get_mds_session(s);
1045                                 seq = di->lease_seq;
1046                                 di->lease_renew_after = 0;
1047                                 di->lease_renew_from = jiffies;
1048                         }
1049                 }
1050         }
1051         spin_unlock(&dentry->d_lock);
1052
1053         if (session) {
1054                 ceph_mdsc_lease_send_msg(session, dir, dentry,
1055                                          CEPH_MDS_LEASE_RENEW, seq);
1056                 ceph_put_mds_session(session);
1057         }
1058         dout("dentry_lease_is_valid - dentry %p = %d\n", dentry, valid);
1059         return valid;
1060 }
1061
1062 /*
1063  * Check if directory-wide content lease/cap is valid.
1064  */
1065 static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry)
1066 {
1067         struct ceph_inode_info *ci = ceph_inode(dir);
1068         struct ceph_dentry_info *di = ceph_dentry(dentry);
1069         int valid = 0;
1070
1071         spin_lock(&ci->i_ceph_lock);
1072         if (ci->i_shared_gen == di->lease_shared_gen)
1073                 valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
1074         spin_unlock(&ci->i_ceph_lock);
1075         dout("dir_lease_is_valid dir %p v%u dentry %p v%u = %d\n",
1076              dir, (unsigned)ci->i_shared_gen, dentry,
1077              (unsigned)di->lease_shared_gen, valid);
1078         return valid;
1079 }
1080
1081 /*
1082  * Check if cached dentry can be trusted.
1083  */
1084 static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
1085 {
1086         int valid = 0;
1087         struct dentry *parent;
1088         struct inode *dir;
1089
1090         if (flags & LOOKUP_RCU)
1091                 return -ECHILD;
1092
1093         dout("d_revalidate %p '%pd' inode %p offset %lld\n", dentry,
1094              dentry, d_inode(dentry), ceph_dentry(dentry)->offset);
1095
1096         parent = dget_parent(dentry);
1097         dir = d_inode(parent);
1098
1099         /* always trust cached snapped dentries, snapdir dentry */
1100         if (ceph_snap(dir) != CEPH_NOSNAP) {
1101                 dout("d_revalidate %p '%pd' inode %p is SNAPPED\n", dentry,
1102                      dentry, d_inode(dentry));
1103                 valid = 1;
1104         } else if (d_really_is_positive(dentry) &&
1105                    ceph_snap(d_inode(dentry)) == CEPH_SNAPDIR) {
1106                 valid = 1;
1107         } else if (dentry_lease_is_valid(dentry) ||
1108                    dir_lease_is_valid(dir, dentry)) {
1109                 if (d_really_is_positive(dentry))
1110                         valid = ceph_is_any_caps(d_inode(dentry));
1111                 else
1112                         valid = 1;
1113         }
1114
1115         if (!valid) {
1116                 struct ceph_mds_client *mdsc =
1117                         ceph_sb_to_client(dir->i_sb)->mdsc;
1118                 struct ceph_mds_request *req;
1119                 int op, mask, err;
1120
1121                 op = ceph_snap(dir) == CEPH_SNAPDIR ?
1122                         CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
1123                 req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
1124                 if (!IS_ERR(req)) {
1125                         req->r_dentry = dget(dentry);
1126                         req->r_num_caps = 2;
1127
1128                         mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
1129                         if (ceph_security_xattr_wanted(dir))
1130                                 mask |= CEPH_CAP_XATTR_SHARED;
1131                         req->r_args.getattr.mask = mask;
1132
1133                         req->r_locked_dir = dir;
1134                         err = ceph_mdsc_do_request(mdsc, NULL, req);
1135                         if (err == 0 || err == -ENOENT) {
1136                                 if (dentry == req->r_dentry) {
1137                                         valid = !d_unhashed(dentry);
1138                                 } else {
1139                                         d_invalidate(req->r_dentry);
1140                                         err = -EAGAIN;
1141                                 }
1142                         }
1143                         ceph_mdsc_put_request(req);
1144                         dout("d_revalidate %p lookup result=%d\n",
1145                              dentry, err);
1146                 }
1147         }
1148
1149         dout("d_revalidate %p %s\n", dentry, valid ? "valid" : "invalid");
1150         if (valid) {
1151                 ceph_dentry_lru_touch(dentry);
1152         } else {
1153                 ceph_dir_clear_complete(dir);
1154         }
1155
1156         dput(parent);
1157         return valid;
1158 }
1159
1160 /*
1161  * Release our ceph_dentry_info.
1162  */
1163 static void ceph_d_release(struct dentry *dentry)
1164 {
1165         struct ceph_dentry_info *di = ceph_dentry(dentry);
1166
1167         dout("d_release %p\n", dentry);
1168         ceph_dentry_lru_del(dentry);
1169         if (di->lease_session)
1170                 ceph_put_mds_session(di->lease_session);
1171         kmem_cache_free(ceph_dentry_cachep, di);
1172         dentry->d_fsdata = NULL;
1173 }
1174
1175 static int ceph_snapdir_d_revalidate(struct dentry *dentry,
1176                                           unsigned int flags)
1177 {
1178         /*
1179          * Eventually, we'll want to revalidate snapped metadata
1180          * too... probably...
1181          */
1182         return 1;
1183 }
1184
1185 /*
1186  * When the VFS prunes a dentry from the cache, we need to clear the
1187  * complete flag on the parent directory.
1188  *
1189  * Called under dentry->d_lock.
1190  */
1191 static void ceph_d_prune(struct dentry *dentry)
1192 {
1193         dout("ceph_d_prune %p\n", dentry);
1194
1195         /* do we have a valid parent? */
1196         if (IS_ROOT(dentry))
1197                 return;
1198
1199         /* if we are not hashed, we don't affect dir's completeness */
1200         if (d_unhashed(dentry))
1201                 return;
1202
1203         /*
1204          * we hold d_lock, so d_parent is stable, and d_fsdata is never
1205          * cleared until d_release
1206          */
1207         ceph_dir_clear_complete(d_inode(dentry->d_parent));
1208 }
1209
1210 /*
1211  * read() on a dir.  This weird interface hack only works if mounted
1212  * with '-o dirstat'.
1213  */
1214 static ssize_t ceph_read_dir(struct file *file, char __user *buf, size_t size,
1215                              loff_t *ppos)
1216 {
1217         struct ceph_file_info *cf = file->private_data;
1218         struct inode *inode = file_inode(file);
1219         struct ceph_inode_info *ci = ceph_inode(inode);
1220         int left;
1221         const int bufsize = 1024;
1222
1223         if (!ceph_test_mount_opt(ceph_sb_to_client(inode->i_sb), DIRSTAT))
1224                 return -EISDIR;
1225
1226         if (!cf->dir_info) {
1227                 cf->dir_info = kmalloc(bufsize, GFP_KERNEL);
1228                 if (!cf->dir_info)
1229                         return -ENOMEM;
1230                 cf->dir_info_len =
1231                         snprintf(cf->dir_info, bufsize,
1232                                 "entries:   %20lld\n"
1233                                 " files:    %20lld\n"
1234                                 " subdirs:  %20lld\n"
1235                                 "rentries:  %20lld\n"
1236                                 " rfiles:   %20lld\n"
1237                                 " rsubdirs: %20lld\n"
1238                                 "rbytes:    %20lld\n"
1239                                 "rctime:    %10ld.%09ld\n",
1240                                 ci->i_files + ci->i_subdirs,
1241                                 ci->i_files,
1242                                 ci->i_subdirs,
1243                                 ci->i_rfiles + ci->i_rsubdirs,
1244                                 ci->i_rfiles,
1245                                 ci->i_rsubdirs,
1246                                 ci->i_rbytes,
1247                                 (long)ci->i_rctime.tv_sec,
1248                                 (long)ci->i_rctime.tv_nsec);
1249         }
1250
1251         if (*ppos >= cf->dir_info_len)
1252                 return 0;
1253         size = min_t(unsigned, size, cf->dir_info_len-*ppos);
1254         left = copy_to_user(buf, cf->dir_info + *ppos, size);
1255         if (left == size)
1256                 return -EFAULT;
1257         *ppos += (size - left);
1258         return size - left;
1259 }
1260
1261 /*
1262  * We maintain a private dentry LRU.
1263  *
1264  * FIXME: this needs to be changed to a per-mds lru to be useful.
1265  */
1266 void ceph_dentry_lru_add(struct dentry *dn)
1267 {
1268         struct ceph_dentry_info *di = ceph_dentry(dn);
1269         struct ceph_mds_client *mdsc;
1270
1271         dout("dentry_lru_add %p %p '%pd'\n", di, dn, dn);
1272         mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1273         spin_lock(&mdsc->dentry_lru_lock);
1274         list_add_tail(&di->lru, &mdsc->dentry_lru);
1275         mdsc->num_dentry++;
1276         spin_unlock(&mdsc->dentry_lru_lock);
1277 }
1278
1279 void ceph_dentry_lru_touch(struct dentry *dn)
1280 {
1281         struct ceph_dentry_info *di = ceph_dentry(dn);
1282         struct ceph_mds_client *mdsc;
1283
1284         dout("dentry_lru_touch %p %p '%pd' (offset %lld)\n", di, dn, dn,
1285              di->offset);
1286         mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1287         spin_lock(&mdsc->dentry_lru_lock);
1288         list_move_tail(&di->lru, &mdsc->dentry_lru);
1289         spin_unlock(&mdsc->dentry_lru_lock);
1290 }
1291
1292 void ceph_dentry_lru_del(struct dentry *dn)
1293 {
1294         struct ceph_dentry_info *di = ceph_dentry(dn);
1295         struct ceph_mds_client *mdsc;
1296
1297         dout("dentry_lru_del %p %p '%pd'\n", di, dn, dn);
1298         mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1299         spin_lock(&mdsc->dentry_lru_lock);
1300         list_del_init(&di->lru);
1301         mdsc->num_dentry--;
1302         spin_unlock(&mdsc->dentry_lru_lock);
1303 }
1304
1305 /*
1306  * Return name hash for a given dentry.  This is dependent on
1307  * the parent directory's hash function.
1308  */
1309 unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
1310 {
1311         struct ceph_inode_info *dci = ceph_inode(dir);
1312
1313         switch (dci->i_dir_layout.dl_dir_hash) {
1314         case 0: /* for backward compat */
1315         case CEPH_STR_HASH_LINUX:
1316                 return dn->d_name.hash;
1317
1318         default:
1319                 return ceph_str_hash(dci->i_dir_layout.dl_dir_hash,
1320                                      dn->d_name.name, dn->d_name.len);
1321         }
1322 }
1323
1324 const struct file_operations ceph_dir_fops = {
1325         .read = ceph_read_dir,
1326         .iterate = ceph_readdir,
1327         .llseek = ceph_dir_llseek,
1328         .open = ceph_open,
1329         .release = ceph_release,
1330         .unlocked_ioctl = ceph_ioctl,
1331         .fsync = ceph_fsync,
1332 };
1333
1334 const struct file_operations ceph_snapdir_fops = {
1335         .iterate = ceph_readdir,
1336         .llseek = ceph_dir_llseek,
1337         .open = ceph_open,
1338         .release = ceph_release,
1339 };
1340
1341 const struct inode_operations ceph_dir_iops = {
1342         .lookup = ceph_lookup,
1343         .permission = ceph_permission,
1344         .getattr = ceph_getattr,
1345         .setattr = ceph_setattr,
1346         .setxattr = generic_setxattr,
1347         .getxattr = generic_getxattr,
1348         .listxattr = ceph_listxattr,
1349         .removexattr = generic_removexattr,
1350         .get_acl = ceph_get_acl,
1351         .set_acl = ceph_set_acl,
1352         .mknod = ceph_mknod,
1353         .symlink = ceph_symlink,
1354         .mkdir = ceph_mkdir,
1355         .link = ceph_link,
1356         .unlink = ceph_unlink,
1357         .rmdir = ceph_unlink,
1358         .rename = ceph_rename,
1359         .create = ceph_create,
1360         .atomic_open = ceph_atomic_open,
1361 };
1362
1363 const struct inode_operations ceph_snapdir_iops = {
1364         .lookup = ceph_lookup,
1365         .permission = ceph_permission,
1366         .getattr = ceph_getattr,
1367         .mkdir = ceph_mkdir,
1368         .rmdir = ceph_unlink,
1369         .rename = ceph_rename,
1370 };
1371
1372 const struct dentry_operations ceph_dentry_ops = {
1373         .d_revalidate = ceph_d_revalidate,
1374         .d_release = ceph_d_release,
1375         .d_prune = ceph_d_prune,
1376 };
1377
1378 const struct dentry_operations ceph_snapdir_dentry_ops = {
1379         .d_revalidate = ceph_snapdir_d_revalidate,
1380         .d_release = ceph_d_release,
1381 };
1382
1383 const struct dentry_operations ceph_snap_dentry_ops = {
1384         .d_release = ceph_d_release,
1385         .d_prune = ceph_d_prune,
1386 };