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         di->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 f_pos for readdir:
  74  * - hash order:
  75  *      (0xff << 52) | ((24 bits hash) << 28) |
  76  *      (the nth entry has hash collision);
  77  * - frag+name order;
  78  *      ((frag value) << 28) | (the nth entry in frag);
  79  */
  80 #define OFFSET_BITS     28
  81 #define OFFSET_MASK     ((1 << OFFSET_BITS) - 1)
  82 #define HASH_ORDER      (0xffull << (OFFSET_BITS + 24))
  83 loff_t ceph_make_fpos(unsigned high, unsigned off, bool hash_order)
  84 {
  85         loff_t fpos = ((loff_t)high << 28) | (loff_t)off;
  86         if (hash_order)
  87                 fpos |= HASH_ORDER;
  88         return fpos;
  89 }
  90
  91 static bool is_hash_order(loff_t p)
  92 {
  93         return (p & HASH_ORDER) == HASH_ORDER;
  94 }
  95
  96 static unsigned fpos_frag(loff_t p)
  97 {
  98         return p >> OFFSET_BITS;
  99 }
 100
 101 static unsigned fpos_hash(loff_t p)
 102 {
 103         return ceph_frag_value(fpos_frag(p));
 104 }
 105
 106 static unsigned fpos_off(loff_t p)
 107 {
 108         return p & OFFSET_MASK;
 109 }
 110
 111 static int fpos_cmp(loff_t l, loff_t r)
 112 {
 113         int v = ceph_frag_compare(fpos_frag(l), fpos_frag(r));
 114         if (v)
 115                 return v;
 116         return (int)(fpos_off(l) - fpos_off(r));
 117 }
 118
 119 /*
 120  * make note of the last dentry we read, so we can
 121  * continue at the same lexicographical point,
 122  * regardless of what dir changes take place on the
 123  * server.
 124  */
 125 static int note_last_dentry(struct ceph_file_info *fi, const char *name,
 126                             int len, unsigned next_offset)
 127 {
 128         char *buf = kmalloc(len+1, GFP_KERNEL);
 129         if (!buf)
 130                 return -ENOMEM;
 131         kfree(fi->last_name);
 132         fi->last_name = buf;
 133         memcpy(fi->last_name, name, len);
 134         fi->last_name[len] = 0;
 135         fi->next_offset = next_offset;
 136         dout("note_last_dentry '%s'\n", fi->last_name);
 137         return 0;
 138 }
 139
 140
 141 static struct dentry *
 142 __dcache_find_get_entry(struct dentry *parent, u64 idx,
 143                         struct ceph_readdir_cache_control *cache_ctl)
 144 {
 145         struct inode *dir = d_inode(parent);
 146         struct dentry *dentry;
 147         unsigned idx_mask = (PAGE_SIZE / sizeof(struct dentry *)) - 1;
 148         loff_t ptr_pos = idx * sizeof(struct dentry *);
 149         pgoff_t ptr_pgoff = ptr_pos >> PAGE_SHIFT;
 150
 151         if (ptr_pos >= i_size_read(dir))
 152                 return NULL;
 153
 154         if (!cache_ctl->page || ptr_pgoff != page_index(cache_ctl->page)) {
 155                 ceph_readdir_cache_release(cache_ctl);
 156                 cache_ctl->page = find_lock_page(&dir->i_data, ptr_pgoff);
 157                 if (!cache_ctl->page) {
 158                         dout(" page %lu not found\n", ptr_pgoff);
 159                         return ERR_PTR(-EAGAIN);
 160                 }
 161                 /* reading/filling the cache are serialized by
 162                    i_mutex, no need to use page lock */
 163                 unlock_page(cache_ctl->page);
 164                 cache_ctl->dentries = kmap(cache_ctl->page);
 165         }
 166
 167         cache_ctl->index = idx & idx_mask;
 168
 169         rcu_read_lock();
 170         spin_lock(&parent->d_lock);
 171         /* check i_size again here, because empty directory can be
 172          * marked as complete while not holding the i_mutex. */
 173         if (ceph_dir_is_complete_ordered(dir) && ptr_pos < i_size_read(dir))
 174                 dentry = cache_ctl->dentries[cache_ctl->index];
 175         else
 176                 dentry = NULL;
 177         spin_unlock(&parent->d_lock);
 178         if (dentry && !lockref_get_not_dead(&dentry->d_lockref))
 179                 dentry = NULL;
 180         rcu_read_unlock();
 181         return dentry ? : ERR_PTR(-EAGAIN);
 182 }
 183
 184 /*
 185  * When possible, we try to satisfy a readdir by peeking at the
 186  * dcache.  We make this work by carefully ordering dentries on
 187  * d_child when we initially get results back from the MDS, and
 188  * falling back to a "normal" sync readdir if any dentries in the dir
 189  * are dropped.
 190  *
 191  * Complete dir indicates that we have all dentries in the dir.  It is
 192  * defined IFF we hold CEPH_CAP_FILE_SHARED (which will be revoked by
 193  * the MDS if/when the directory is modified).
 194  */
 195 static int __dcache_readdir(struct file *file,  struct dir_context *ctx,
 196                             u32 shared_gen)
 197 {
 198         struct ceph_file_info *fi = file->private_data;
 199         struct dentry *parent = file->f_path.dentry;
 200         struct inode *dir = d_inode(parent);
 201         struct dentry *dentry, *last = NULL;
 202         struct ceph_dentry_info *di;
 203         struct ceph_readdir_cache_control cache_ctl = {};
 204         u64 idx = 0;
 205         int err = 0;
 206
 207         dout("__dcache_readdir %p v%u at %llx\n", dir, shared_gen, ctx->pos);
 208
 209         /* search start position */
 210         if (ctx->pos > 2) {
 211                 u64 count = div_u64(i_size_read(dir), sizeof(struct dentry *));
 212                 while (count > 0) {
 213                         u64 step = count >> 1;
 214                         dentry = __dcache_find_get_entry(parent, idx + step,
 215                                                          &cache_ctl);
 216                         if (!dentry) {
 217                                 /* use linar search */
 218                                 idx = 0;
 219                                 break;
 220                         }
 221                         if (IS_ERR(dentry)) {
 222                                 err = PTR_ERR(dentry);
 223                                 goto out;
 224                         }
 225                         di = ceph_dentry(dentry);
 226                         spin_lock(&dentry->d_lock);
 227                         if (fpos_cmp(di->offset, ctx->pos) < 0) {
 228                                 idx += step + 1;
 229                                 count -= step + 1;
 230                         } else {
 231                                 count = step;
 232                         }
 233                         spin_unlock(&dentry->d_lock);
 234                         dput(dentry);
 235                 }
 236
 237                 dout("__dcache_readdir %p cache idx %llu\n", dir, idx);
 238         }
 239
 240
 241         for (;;) {
 242                 bool emit_dentry = false;
 243                 dentry = __dcache_find_get_entry(parent, idx++, &cache_ctl);
 244                 if (!dentry) {
 245                         fi->flags |= CEPH_F_ATEND;
 246                         err = 0;
 247                         break;
 248                 }
 249                 if (IS_ERR(dentry)) {
 250                         err = PTR_ERR(dentry);
 251                         goto out;
 252                 }
 253
 254                 di = ceph_dentry(dentry);
 255                 spin_lock(&dentry->d_lock);
 256                 if (di->lease_shared_gen == shared_gen &&
 257                     d_really_is_positive(dentry) &&
 258                     fpos_cmp(ctx->pos, di->offset) <= 0) {
 259                         emit_dentry = true;
 260                 }
 261                 spin_unlock(&dentry->d_lock);
 262
 263                 if (emit_dentry) {
 264                         dout(" %llx dentry %p %pd %p\n", di->offset,
 265                              dentry, dentry, d_inode(dentry));
 266                         ctx->pos = di->offset;
 267                         if (!dir_emit(ctx, dentry->d_name.name,
 268                                       dentry->d_name.len,
 269                                       ceph_translate_ino(dentry->d_sb,
 270                                                          d_inode(dentry)->i_ino),
 271                                       d_inode(dentry)->i_mode >> 12)) {
 272                                 dput(dentry);
 273                                 err = 0;
 274                                 break;
 275                         }
 276                         ctx->pos++;
 277
 278                         if (last)
 279                                 dput(last);
 280                         last = dentry;
 281                 } else {
 282                         dput(dentry);
 283                 }
 284         }
 285 out:
 286         ceph_readdir_cache_release(&cache_ctl);
 287         if (last) {
 288                 int ret;
 289                 di = ceph_dentry(last);
 290                 ret = note_last_dentry(fi, last->d_name.name, last->d_name.len,
 291                                        fpos_off(di->offset) + 1);
 292                 if (ret < 0)
 293                         err = ret;
 294                 dput(last);
 295                 /* last_name no longer match cache index */
 296                 if (fi->readdir_cache_idx >= 0) {
 297                         fi->readdir_cache_idx = -1;
 298                         fi->dir_release_count = 0;
 299                 }
 300         }
 301         return err;
 302 }
 303
 304 static bool need_send_readdir(struct ceph_file_info *fi, loff_t pos)
 305 {
 306         if (!fi->last_readdir)
 307                 return true;
 308         if (is_hash_order(pos))
 309                 return !ceph_frag_contains_value(fi->frag, fpos_hash(pos));
 310         else
 311                 return fi->frag != fpos_frag(pos);
 312 }
 313
 314 static int ceph_readdir(struct file *file, struct dir_context *ctx)
 315 {
 316         struct ceph_file_info *fi = file->private_data;
 317         struct inode *inode = file_inode(file);
 318         struct ceph_inode_info *ci = ceph_inode(inode);
 319         struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 320         struct ceph_mds_client *mdsc = fsc->mdsc;
 321         int i;
 322         int err;
 323         unsigned frag = -1;
 324         struct ceph_mds_reply_info_parsed *rinfo;
 325
 326         dout("readdir %p file %p pos %llx\n", inode, file, ctx->pos);
 327         if (fi->flags & CEPH_F_ATEND)
 328                 return 0;
 329
 330         /* always start with . and .. */
 331         if (ctx->pos == 0) {
 332                 dout("readdir off 0 -> '.'\n");
 333                 if (!dir_emit(ctx, ".", 1,
 334                             ceph_translate_ino(inode->i_sb, inode->i_ino),
 335                             inode->i_mode >> 12))
 336                         return 0;
 337                 ctx->pos = 1;
 338         }
 339         if (ctx->pos == 1) {
 340                 ino_t ino = parent_ino(file->f_path.dentry);
 341                 dout("readdir off 1 -> '..'\n");
 342                 if (!dir_emit(ctx, "..", 2,
 343                             ceph_translate_ino(inode->i_sb, ino),
 344                             inode->i_mode >> 12))
 345                         return 0;
 346                 ctx->pos = 2;
 347         }
 348
 349         /* can we use the dcache? */
 350         spin_lock(&ci->i_ceph_lock);
 351         if (ceph_test_mount_opt(fsc, DCACHE) &&
 352             !ceph_test_mount_opt(fsc, NOASYNCREADDIR) &&
 353             ceph_snap(inode) != CEPH_SNAPDIR &&
 354             __ceph_dir_is_complete_ordered(ci) &&
 355             __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1)) {
 356                 u32 shared_gen = ci->i_shared_gen;
 357                 spin_unlock(&ci->i_ceph_lock);
 358                 err = __dcache_readdir(file, ctx, shared_gen);
 359                 if (err != -EAGAIN)
 360                         return err;
 361         } else {
 362                 spin_unlock(&ci->i_ceph_lock);
 363         }
 364
 365         /* proceed with a normal readdir */
 366 more:
 367         /* do we have the correct frag content buffered? */
 368         if (need_send_readdir(fi, ctx->pos)) {
 369                 struct ceph_mds_request *req;
 370                 int op = ceph_snap(inode) == CEPH_SNAPDIR ?
 371                         CEPH_MDS_OP_LSSNAP : CEPH_MDS_OP_READDIR;
 372
 373                 /* discard old result, if any */
 374                 if (fi->last_readdir) {
 375                         ceph_mdsc_put_request(fi->last_readdir);
 376                         fi->last_readdir = NULL;
 377                 }
 378
 379                 if (is_hash_order(ctx->pos)) {
 380                         /* fragtree isn't always accurate. choose frag
 381                          * based on previous reply when possible. */
 382                         if (frag == (unsigned)-1)
 383                                 frag = ceph_choose_frag(ci, fpos_hash(ctx->pos),
 384                                                         NULL, NULL);
 385                 } else {
 386                         frag = fpos_frag(ctx->pos);
 387                 }
 388
 389                 dout("readdir fetching %llx.%llx frag %x offset '%s'\n",
 390                      ceph_vinop(inode), frag, fi->last_name);
 391                 req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
 392                 if (IS_ERR(req))
 393                         return PTR_ERR(req);
 394                 err = ceph_alloc_readdir_reply_buffer(req, inode);
 395                 if (err) {
 396                         ceph_mdsc_put_request(req);
 397                         return err;
 398                 }
 399                 /* hints to request -> mds selection code */
 400                 req->r_direct_mode = USE_AUTH_MDS;
 401                 req->r_direct_hash = ceph_frag_value(frag);
 402                 req->r_direct_is_hash = true;
 403                 if (fi->last_name) {
 404                         req->r_path2 = kstrdup(fi->last_name, GFP_KERNEL);
 405                         if (!req->r_path2) {
 406                                 ceph_mdsc_put_request(req);
 407                                 return -ENOMEM;
 408                         }
 409                 }
 410                 req->r_dir_release_cnt = fi->dir_release_count;
 411                 req->r_dir_ordered_cnt = fi->dir_ordered_count;
 412                 req->r_readdir_cache_idx = fi->readdir_cache_idx;
 413                 req->r_readdir_offset = fi->next_offset;
 414                 req->r_args.readdir.frag = cpu_to_le32(frag);
 415                 req->r_args.readdir.flags =
 416                                 cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS);
 417
 418                 req->r_inode = inode;
 419                 ihold(inode);
 420                 req->r_dentry = dget(file->f_path.dentry);
 421                 err = ceph_mdsc_do_request(mdsc, NULL, req);
 422                 if (err < 0) {
 423                         ceph_mdsc_put_request(req);
 424                         return err;
 425                 }
 426                 dout("readdir got and parsed readdir result=%d on "
 427                      "frag %x, end=%d, complete=%d, hash_order=%d\n",
 428                      err, frag,
 429                      (int)req->r_reply_info.dir_end,
 430                      (int)req->r_reply_info.dir_complete,
 431                      (int)req->r_reply_info.hash_order);
 432
 433                 rinfo = &req->r_reply_info;
 434                 if (le32_to_cpu(rinfo->dir_dir->frag) != frag) {
 435                         frag = le32_to_cpu(rinfo->dir_dir->frag);
 436                         if (!rinfo->hash_order) {
 437                                 fi->next_offset = req->r_readdir_offset;
 438                                 /* adjust ctx->pos to beginning of frag */
 439                                 ctx->pos = ceph_make_fpos(frag,
 440                                                           fi->next_offset,
 441                                                           false);
 442                         }
 443                 }
 444
 445                 fi->frag = frag;
 446                 fi->last_readdir = req;
 447
 448                 if (req->r_did_prepopulate) {
 449                         fi->readdir_cache_idx = req->r_readdir_cache_idx;
 450                         if (fi->readdir_cache_idx < 0) {
 451                                 /* preclude from marking dir ordered */
 452                                 fi->dir_ordered_count = 0;
 453                         } else if (ceph_frag_is_leftmost(frag) &&
 454                                    fi->next_offset == 2) {
 455                                 /* note dir version at start of readdir so
 456                                  * we can tell if any dentries get dropped */
 457                                 fi->dir_release_count = req->r_dir_release_cnt;
 458                                 fi->dir_ordered_count = req->r_dir_ordered_cnt;
 459                         }
 460                 } else {
 461                         dout("readdir !did_prepopulate");
 462                         /* disable readdir cache */
 463                         fi->readdir_cache_idx = -1;
 464                         /* preclude from marking dir complete */
 465                         fi->dir_release_count = 0;
 466                 }
 467
 468                 /* note next offset and last dentry name */
 469                 if (rinfo->dir_nr > 0) {
 470                         struct ceph_mds_reply_dir_entry *rde =
 471                                         rinfo->dir_entries + (rinfo->dir_nr-1);
 472                         unsigned next_offset = req->r_reply_info.dir_end ?
 473                                         2 : (fpos_off(rde->offset) + 1);
 474                         err = note_last_dentry(fi, rde->name, rde->name_len,
 475                                                next_offset);
 476                         if (err)
 477                                 return err;
 478                 } else if (req->r_reply_info.dir_end) {
 479                         fi->next_offset = 2;
 480                         /* keep last name */
 481                 }
 482         }
 483
 484         rinfo = &fi->last_readdir->r_reply_info;
 485         dout("readdir frag %x num %d pos %llx chunk first %llx\n",
 486              fi->frag, rinfo->dir_nr, ctx->pos,
 487              rinfo->dir_nr ? rinfo->dir_entries[0].offset : 0LL);
 488
 489         i = 0;
 490         /* search start position */
 491         if (rinfo->dir_nr > 0) {
 492                 int step, nr = rinfo->dir_nr;
 493                 while (nr > 0) {
 494                         step = nr >> 1;
 495                         if (rinfo->dir_entries[i + step].offset < ctx->pos) {
 496                                 i +=  step + 1;
 497                                 nr -= step + 1;
 498                         } else {
 499                                 nr = step;
 500                         }
 501                 }
 502         }
 503         for (; i < rinfo->dir_nr; i++) {
 504                 struct ceph_mds_reply_dir_entry *rde = rinfo->dir_entries + i;
 505                 struct ceph_vino vino;
 506                 ino_t ino;
 507                 u32 ftype;
 508
 509                 BUG_ON(rde->offset < ctx->pos);
 510
 511                 ctx->pos = rde->offset;
 512                 dout("readdir (%d/%d) -> %llx '%.*s' %p\n",
 513                      i, rinfo->dir_nr, ctx->pos,
 514                      rde->name_len, rde->name, &rde->inode.in);
 515
 516                 BUG_ON(!rde->inode.in);
 517                 ftype = le32_to_cpu(rde->inode.in->mode) >> 12;
 518                 vino.ino = le64_to_cpu(rde->inode.in->ino);
 519                 vino.snap = le64_to_cpu(rde->inode.in->snapid);
 520                 ino = ceph_vino_to_ino(vino);
 521
 522                 if (!dir_emit(ctx, rde->name, rde->name_len,
 523                               ceph_translate_ino(inode->i_sb, ino), ftype)) {
 524                         dout("filldir stopping us...\n");
 525                         return 0;
 526                 }
 527                 ctx->pos++;
 528         }
 529
 530         ceph_mdsc_put_request(fi->last_readdir);
 531         fi->last_readdir = NULL;
 532
 533         if (fi->next_offset > 2) {
 534                 frag = fi->frag;
 535                 goto more;
 536         }
 537
 538         /* more frags? */
 539         if (!ceph_frag_is_rightmost(fi->frag)) {
 540                 frag = ceph_frag_next(fi->frag);
 541                 if (is_hash_order(ctx->pos)) {
 542                         loff_t new_pos = ceph_make_fpos(ceph_frag_value(frag),
 543                                                         fi->next_offset, true);
 544                         if (new_pos > ctx->pos)
 545                                 ctx->pos = new_pos;
 546                         /* keep last_name */
 547                 } else {
 548                         ctx->pos = ceph_make_fpos(frag, fi->next_offset, false);
 549                         kfree(fi->last_name);
 550                         fi->last_name = NULL;
 551                 }
 552                 dout("readdir next frag is %x\n", frag);
 553                 goto more;
 554         }
 555         fi->flags |= CEPH_F_ATEND;
 556
 557         /*
 558          * if dir_release_count still matches the dir, no dentries
 559          * were released during the whole readdir, and we should have
 560          * the complete dir contents in our cache.
 561          */
 562         if (atomic64_read(&ci->i_release_count) == fi->dir_release_count) {
 563                 spin_lock(&ci->i_ceph_lock);
 564                 if (fi->dir_ordered_count == atomic64_read(&ci->i_ordered_count)) {
 565                         dout(" marking %p complete and ordered\n", inode);
 566                         /* use i_size to track number of entries in
 567                          * readdir cache */
 568                         BUG_ON(fi->readdir_cache_idx < 0);
 569                         i_size_write(inode, fi->readdir_cache_idx *
 570                                      sizeof(struct dentry*));
 571                 } else {
 572                         dout(" marking %p complete\n", inode);
 573                 }
 574                 __ceph_dir_set_complete(ci, fi->dir_release_count,
 575                                         fi->dir_ordered_count);
 576                 spin_unlock(&ci->i_ceph_lock);
 577         }
 578
 579         dout("readdir %p file %p done.\n", inode, file);
 580         return 0;
 581 }
 582
 583 static void reset_readdir(struct ceph_file_info *fi)
 584 {
 585         if (fi->last_readdir) {
 586                 ceph_mdsc_put_request(fi->last_readdir);
 587                 fi->last_readdir = NULL;
 588         }
 589         kfree(fi->last_name);
 590         fi->last_name = NULL;
 591         fi->dir_release_count = 0;
 592         fi->readdir_cache_idx = -1;
 593         fi->next_offset = 2;  /* compensate for . and .. */
 594         fi->flags &= ~CEPH_F_ATEND;
 595 }
 596
 597 /*
 598  * discard buffered readdir content on seekdir(0), or seek to new frag,
 599  * or seek prior to current chunk
 600  */
 601 static bool need_reset_readdir(struct ceph_file_info *fi, loff_t new_pos)
 602 {
 603         struct ceph_mds_reply_info_parsed *rinfo;
 604         loff_t chunk_offset;
 605         if (new_pos == 0)
 606                 return true;
 607         if (is_hash_order(new_pos)) {
 608                 /* no need to reset last_name for a forward seek when
 609                  * dentries are sotred in hash order */
 610         } else if (fi->frag != fpos_frag(new_pos)) {
 611                 return true;
 612         }
 613         rinfo = fi->last_readdir ? &fi->last_readdir->r_reply_info : NULL;
 614         if (!rinfo || !rinfo->dir_nr)
 615                 return true;
 616         chunk_offset = rinfo->dir_entries[0].offset;
 617         return new_pos < chunk_offset ||
 618                is_hash_order(new_pos) != is_hash_order(chunk_offset);
 619 }
 620
 621 static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int whence)
 622 {
 623         struct ceph_file_info *fi = file->private_data;
 624         struct inode *inode = file->f_mapping->host;
 625         loff_t retval;
 626
 627         inode_lock(inode);
 628         retval = -EINVAL;
 629         switch (whence) {
 630         case SEEK_CUR:
 631                 offset += file->f_pos;
 632         case SEEK_SET:
 633                 break;
 634         case SEEK_END:
 635                 retval = -EOPNOTSUPP;
 636         default:
 637                 goto out;
 638         }
 639
 640         if (offset >= 0) {
 641                 if (need_reset_readdir(fi, offset)) {
 642                         dout("dir_llseek dropping %p content\n", file);
 643                         reset_readdir(fi);
 644                 } else if (is_hash_order(offset) && offset > file->f_pos) {
 645                         /* for hash offset, we don't know if a forward seek
 646                          * is within same frag */
 647                         fi->dir_release_count = 0;
 648                         fi->readdir_cache_idx = -1;
 649                 }
 650
 651                 if (offset != file->f_pos) {
 652                         file->f_pos = offset;
 653                         file->f_version = 0;
 654                         fi->flags &= ~CEPH_F_ATEND;
 655                 }
 656                 retval = offset;
 657         }
 658 out:
 659         inode_unlock(inode);
 660         return retval;
 661 }
 662
 663 /*
 664  * Handle lookups for the hidden .snap directory.
 665  */
 666 int ceph_handle_snapdir(struct ceph_mds_request *req,
 667                         struct dentry *dentry, int err)
 668 {
 669         struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
 670         struct inode *parent = d_inode(dentry->d_parent); /* we hold i_mutex */
 671
 672         /* .snap dir? */
 673         if (err == -ENOENT &&
 674             ceph_snap(parent) == CEPH_NOSNAP &&
 675             strcmp(dentry->d_name.name,
 676                    fsc->mount_options->snapdir_name) == 0) {
 677                 struct inode *inode = ceph_get_snapdir(parent);
 678                 dout("ENOENT on snapdir %p '%pd', linking to snapdir %p\n",
 679                      dentry, dentry, inode);
 680                 BUG_ON(!d_unhashed(dentry));
 681                 d_add(dentry, inode);
 682                 err = 0;
 683         }
 684         return err;
 685 }
 686
 687 /*
 688  * Figure out final result of a lookup/open request.
 689  *
 690  * Mainly, make sure we return the final req->r_dentry (if it already
 691  * existed) in place of the original VFS-provided dentry when they
 692  * differ.
 693  *
 694  * Gracefully handle the case where the MDS replies with -ENOENT and
 695  * no trace (which it may do, at its discretion, e.g., if it doesn't
 696  * care to issue a lease on the negative dentry).
 697  */
 698 struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
 699                                   struct dentry *dentry, int err)
 700 {
 701         if (err == -ENOENT) {
 702                 /* no trace? */
 703                 err = 0;
 704                 if (!req->r_reply_info.head->is_dentry) {
 705                         dout("ENOENT and no trace, dentry %p inode %p\n",
 706                              dentry, d_inode(dentry));
 707                         if (d_really_is_positive(dentry)) {
 708                                 d_drop(dentry);
 709                                 err = -ENOENT;
 710                         } else {
 711                                 d_add(dentry, NULL);
 712                         }
 713                 }
 714         }
 715         if (err)
 716                 dentry = ERR_PTR(err);
 717         else if (dentry != req->r_dentry)
 718                 dentry = dget(req->r_dentry);   /* we got spliced */
 719         else
 720                 dentry = NULL;
 721         return dentry;
 722 }
 723
 724 static bool is_root_ceph_dentry(struct inode *inode, struct dentry *dentry)
 725 {
 726         return ceph_ino(inode) == CEPH_INO_ROOT &&
 727                 strncmp(dentry->d_name.name, ".ceph", 5) == 0;
 728 }
 729
 730 /*
 731  * Look up a single dir entry.  If there is a lookup intent, inform
 732  * the MDS so that it gets our 'caps wanted' value in a single op.
 733  */
 734 static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
 735                                   unsigned int flags)
 736 {
 737         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 738         struct ceph_mds_client *mdsc = fsc->mdsc;
 739         struct ceph_mds_request *req;
 740         int op;
 741         int mask;
 742         int err;
 743
 744         dout("lookup %p dentry %p '%pd'\n",
 745              dir, dentry, dentry);
 746
 747         if (dentry->d_name.len > NAME_MAX)
 748                 return ERR_PTR(-ENAMETOOLONG);
 749
 750         err = ceph_init_dentry(dentry);
 751         if (err < 0)
 752                 return ERR_PTR(err);
 753
 754         /* can we conclude ENOENT locally? */
 755         if (d_really_is_negative(dentry)) {
 756                 struct ceph_inode_info *ci = ceph_inode(dir);
 757                 struct ceph_dentry_info *di = ceph_dentry(dentry);
 758
 759                 spin_lock(&ci->i_ceph_lock);
 760                 dout(" dir %p flags are %d\n", dir, ci->i_ceph_flags);
 761                 if (strncmp(dentry->d_name.name,
 762                             fsc->mount_options->snapdir_name,
 763                             dentry->d_name.len) &&
 764                     !is_root_ceph_dentry(dir, dentry) &&
 765                     ceph_test_mount_opt(fsc, DCACHE) &&
 766                     __ceph_dir_is_complete(ci) &&
 767                     (__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1))) {
 768                         spin_unlock(&ci->i_ceph_lock);
 769                         dout(" dir %p complete, -ENOENT\n", dir);
 770                         d_add(dentry, NULL);
 771                         di->lease_shared_gen = ci->i_shared_gen;
 772                         return NULL;
 773                 }
 774                 spin_unlock(&ci->i_ceph_lock);
 775         }
 776
 777         op = ceph_snap(dir) == CEPH_SNAPDIR ?
 778                 CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
 779         req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
 780         if (IS_ERR(req))
 781                 return ERR_CAST(req);
 782         req->r_dentry = dget(dentry);
 783         req->r_num_caps = 2;
 784
 785         mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
 786         if (ceph_security_xattr_wanted(dir))
 787                 mask |= CEPH_CAP_XATTR_SHARED;
 788         req->r_args.getattr.mask = cpu_to_le32(mask);
 789
 790         req->r_locked_dir = dir;
 791         err = ceph_mdsc_do_request(mdsc, NULL, req);
 792         err = ceph_handle_snapdir(req, dentry, err);
 793         dentry = ceph_finish_lookup(req, dentry, err);
 794         ceph_mdsc_put_request(req);  /* will dput(dentry) */
 795         dout("lookup result=%p\n", dentry);
 796         return dentry;
 797 }
 798
 799 /*
 800  * If we do a create but get no trace back from the MDS, follow up with
 801  * a lookup (the VFS expects us to link up the provided dentry).
 802  */
 803 int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
 804 {
 805         struct dentry *result = ceph_lookup(dir, dentry, 0);
 806
 807         if (result && !IS_ERR(result)) {
 808                 /*
 809                  * We created the item, then did a lookup, and found
 810                  * it was already linked to another inode we already
 811                  * had in our cache (and thus got spliced). To not
 812                  * confuse VFS (especially when inode is a directory),
 813                  * we don't link our dentry to that inode, return an
 814                  * error instead.
 815                  *
 816                  * This event should be rare and it happens only when
 817                  * we talk to old MDS. Recent MDS does not send traceless
 818                  * reply for request that creates new inode.
 819                  */
 820                 d_drop(result);
 821                 return -ESTALE;
 822         }
 823         return PTR_ERR(result);
 824 }
 825
 826 static int ceph_mknod(struct inode *dir, struct dentry *dentry,
 827                       umode_t mode, dev_t rdev)
 828 {
 829         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 830         struct ceph_mds_client *mdsc = fsc->mdsc;
 831         struct ceph_mds_request *req;
 832         struct ceph_acls_info acls = {};
 833         int err;
 834
 835         if (ceph_snap(dir) != CEPH_NOSNAP)
 836                 return -EROFS;
 837
 838         err = ceph_pre_init_acls(dir, &mode, &acls);
 839         if (err < 0)
 840                 return err;
 841
 842         dout("mknod in dir %p dentry %p mode 0%ho rdev %d\n",
 843              dir, dentry, mode, rdev);
 844         req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_MKNOD, USE_AUTH_MDS);
 845         if (IS_ERR(req)) {
 846                 err = PTR_ERR(req);
 847                 goto out;
 848         }
 849         req->r_dentry = dget(dentry);
 850         req->r_num_caps = 2;
 851         req->r_locked_dir = dir;
 852         req->r_args.mknod.mode = cpu_to_le32(mode);
 853         req->r_args.mknod.rdev = cpu_to_le32(rdev);
 854         req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
 855         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 856         if (acls.pagelist) {
 857                 req->r_pagelist = acls.pagelist;
 858                 acls.pagelist = NULL;
 859         }
 860         err = ceph_mdsc_do_request(mdsc, dir, req);
 861         if (!err && !req->r_reply_info.head->is_dentry)
 862                 err = ceph_handle_notrace_create(dir, dentry);
 863         ceph_mdsc_put_request(req);
 864 out:
 865         if (!err)
 866                 ceph_init_inode_acls(d_inode(dentry), &acls);
 867         else
 868                 d_drop(dentry);
 869         ceph_release_acls_info(&acls);
 870         return err;
 871 }
 872
 873 static int ceph_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 874                        bool excl)
 875 {
 876         return ceph_mknod(dir, dentry, mode, 0);
 877 }
 878
 879 static int ceph_symlink(struct inode *dir, struct dentry *dentry,
 880                             const char *dest)
 881 {
 882         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 883         struct ceph_mds_client *mdsc = fsc->mdsc;
 884         struct ceph_mds_request *req;
 885         int err;
 886
 887         if (ceph_snap(dir) != CEPH_NOSNAP)
 888                 return -EROFS;
 889
 890         dout("symlink in dir %p dentry %p to '%s'\n", dir, dentry, dest);
 891         req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SYMLINK, USE_AUTH_MDS);
 892         if (IS_ERR(req)) {
 893                 err = PTR_ERR(req);
 894                 goto out;
 895         }
 896         req->r_path2 = kstrdup(dest, GFP_KERNEL);
 897         if (!req->r_path2) {
 898                 err = -ENOMEM;
 899                 ceph_mdsc_put_request(req);
 900                 goto out;
 901         }
 902         req->r_locked_dir = dir;
 903         req->r_dentry = dget(dentry);
 904         req->r_num_caps = 2;
 905         req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
 906         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 907         err = ceph_mdsc_do_request(mdsc, dir, req);
 908         if (!err && !req->r_reply_info.head->is_dentry)
 909                 err = ceph_handle_notrace_create(dir, dentry);
 910         ceph_mdsc_put_request(req);
 911 out:
 912         if (err)
 913                 d_drop(dentry);
 914         return err;
 915 }
 916
 917 static int ceph_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 918 {
 919         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 920         struct ceph_mds_client *mdsc = fsc->mdsc;
 921         struct ceph_mds_request *req;
 922         struct ceph_acls_info acls = {};
 923         int err = -EROFS;
 924         int op;
 925
 926         if (ceph_snap(dir) == CEPH_SNAPDIR) {
 927                 /* mkdir .snap/foo is a MKSNAP */
 928                 op = CEPH_MDS_OP_MKSNAP;
 929                 dout("mksnap dir %p snap '%pd' dn %p\n", dir,
 930                      dentry, dentry);
 931         } else if (ceph_snap(dir) == CEPH_NOSNAP) {
 932                 dout("mkdir dir %p dn %p mode 0%ho\n", dir, dentry, mode);
 933                 op = CEPH_MDS_OP_MKDIR;
 934         } else {
 935                 goto out;
 936         }
 937
 938         mode |= S_IFDIR;
 939         err = ceph_pre_init_acls(dir, &mode, &acls);
 940         if (err < 0)
 941                 goto out;
 942
 943         req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
 944         if (IS_ERR(req)) {
 945                 err = PTR_ERR(req);
 946                 goto out;
 947         }
 948
 949         req->r_dentry = dget(dentry);
 950         req->r_num_caps = 2;
 951         req->r_locked_dir = dir;
 952         req->r_args.mkdir.mode = cpu_to_le32(mode);
 953         req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
 954         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 955         if (acls.pagelist) {
 956                 req->r_pagelist = acls.pagelist;
 957                 acls.pagelist = NULL;
 958         }
 959         err = ceph_mdsc_do_request(mdsc, dir, req);
 960         if (!err &&
 961             !req->r_reply_info.head->is_target &&
 962             !req->r_reply_info.head->is_dentry)
 963                 err = ceph_handle_notrace_create(dir, dentry);
 964         ceph_mdsc_put_request(req);
 965 out:
 966         if (!err)
 967                 ceph_init_inode_acls(d_inode(dentry), &acls);
 968         else
 969                 d_drop(dentry);
 970         ceph_release_acls_info(&acls);
 971         return err;
 972 }
 973
 974 static int ceph_link(struct dentry *old_dentry, struct inode *dir,
 975                      struct dentry *dentry)
 976 {
 977         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 978         struct ceph_mds_client *mdsc = fsc->mdsc;
 979         struct ceph_mds_request *req;
 980         int err;
 981
 982         if (ceph_snap(dir) != CEPH_NOSNAP)
 983                 return -EROFS;
 984
 985         dout("link in dir %p old_dentry %p dentry %p\n", dir,
 986              old_dentry, dentry);
 987         req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LINK, USE_AUTH_MDS);
 988         if (IS_ERR(req)) {
 989                 d_drop(dentry);
 990                 return PTR_ERR(req);
 991         }
 992         req->r_dentry = dget(dentry);
 993         req->r_num_caps = 2;
 994         req->r_old_dentry = dget(old_dentry);
 995         req->r_locked_dir = dir;
 996         req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
 997         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 998         /* release LINK_SHARED on source inode (mds will lock it) */
 999         req->r_old_inode_drop = CEPH_CAP_LINK_SHARED;
1000         err = ceph_mdsc_do_request(mdsc, dir, req);
1001         if (err) {
1002                 d_drop(dentry);
1003         } else if (!req->r_reply_info.head->is_dentry) {
1004                 ihold(d_inode(old_dentry));
1005                 d_instantiate(dentry, d_inode(old_dentry));
1006         }
1007         ceph_mdsc_put_request(req);
1008         return err;
1009 }
1010
1011 /*
1012  * For a soon-to-be unlinked file, drop the AUTH_RDCACHE caps.  If it
1013  * looks like the link count will hit 0, drop any other caps (other
1014  * than PIN) we don't specifically want (due to the file still being
1015  * open).
1016  */
1017 static int drop_caps_for_unlink(struct inode *inode)
1018 {
1019         struct ceph_inode_info *ci = ceph_inode(inode);
1020         int drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
1021
1022         spin_lock(&ci->i_ceph_lock);
1023         if (inode->i_nlink == 1) {
1024                 drop |= ~(__ceph_caps_wanted(ci) | CEPH_CAP_PIN);
1025                 ci->i_ceph_flags |= CEPH_I_NODELAY;
1026         }
1027         spin_unlock(&ci->i_ceph_lock);
1028         return drop;
1029 }
1030
1031 /*
1032  * rmdir and unlink are differ only by the metadata op code
1033  */
1034 static int ceph_unlink(struct inode *dir, struct dentry *dentry)
1035 {
1036         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
1037         struct ceph_mds_client *mdsc = fsc->mdsc;
1038         struct inode *inode = d_inode(dentry);
1039         struct ceph_mds_request *req;
1040         int err = -EROFS;
1041         int op;
1042
1043         if (ceph_snap(dir) == CEPH_SNAPDIR) {
1044                 /* rmdir .snap/foo is RMSNAP */
1045                 dout("rmsnap dir %p '%pd' dn %p\n", dir, dentry, dentry);
1046                 op = CEPH_MDS_OP_RMSNAP;
1047         } else if (ceph_snap(dir) == CEPH_NOSNAP) {
1048                 dout("unlink/rmdir dir %p dn %p inode %p\n",
1049                      dir, dentry, inode);
1050                 op = d_is_dir(dentry) ?
1051                         CEPH_MDS_OP_RMDIR : CEPH_MDS_OP_UNLINK;
1052         } else
1053                 goto out;
1054         req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
1055         if (IS_ERR(req)) {
1056                 err = PTR_ERR(req);
1057                 goto out;
1058         }
1059         req->r_dentry = dget(dentry);
1060         req->r_num_caps = 2;
1061         req->r_locked_dir = dir;
1062         req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
1063         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1064         req->r_inode_drop = drop_caps_for_unlink(inode);
1065         err = ceph_mdsc_do_request(mdsc, dir, req);
1066         if (!err && !req->r_reply_info.head->is_dentry)
1067                 d_delete(dentry);
1068         ceph_mdsc_put_request(req);
1069 out:
1070         return err;
1071 }
1072
1073 static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
1074                        struct inode *new_dir, struct dentry *new_dentry,
1075                        unsigned int flags)
1076 {
1077         struct ceph_fs_client *fsc = ceph_sb_to_client(old_dir->i_sb);
1078         struct ceph_mds_client *mdsc = fsc->mdsc;
1079         struct ceph_mds_request *req;
1080         int op = CEPH_MDS_OP_RENAME;
1081         int err;
1082
1083         if (flags)
1084                 return -EINVAL;
1085
1086         if (ceph_snap(old_dir) != ceph_snap(new_dir))
1087                 return -EXDEV;
1088         if (ceph_snap(old_dir) != CEPH_NOSNAP) {
1089                 if (old_dir == new_dir && ceph_snap(old_dir) == CEPH_SNAPDIR)
1090                         op = CEPH_MDS_OP_RENAMESNAP;
1091                 else
1092                         return -EROFS;
1093         }
1094         dout("rename dir %p dentry %p to dir %p dentry %p\n",
1095              old_dir, old_dentry, new_dir, new_dentry);
1096         req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
1097         if (IS_ERR(req))
1098                 return PTR_ERR(req);
1099         ihold(old_dir);
1100         req->r_dentry = dget(new_dentry);
1101         req->r_num_caps = 2;
1102         req->r_old_dentry = dget(old_dentry);
1103         req->r_old_dentry_dir = old_dir;
1104         req->r_locked_dir = new_dir;
1105         req->r_old_dentry_drop = CEPH_CAP_FILE_SHARED;
1106         req->r_old_dentry_unless = CEPH_CAP_FILE_EXCL;
1107         req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
1108         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1109         /* release LINK_RDCACHE on source inode (mds will lock it) */
1110         req->r_old_inode_drop = CEPH_CAP_LINK_SHARED;
1111         if (d_really_is_positive(new_dentry))
1112                 req->r_inode_drop = drop_caps_for_unlink(d_inode(new_dentry));
1113         err = ceph_mdsc_do_request(mdsc, old_dir, req);
1114         if (!err && !req->r_reply_info.head->is_dentry) {
1115                 /*
1116                  * Normally d_move() is done by fill_trace (called by
1117                  * do_request, above).  If there is no trace, we need
1118                  * to do it here.
1119                  */
1120
1121                 /* d_move screws up sibling dentries' offsets */
1122                 ceph_dir_clear_complete(old_dir);
1123                 ceph_dir_clear_complete(new_dir);
1124
1125                 d_move(old_dentry, new_dentry);
1126
1127                 /* ensure target dentry is invalidated, despite
1128                    rehashing bug in vfs_rename_dir */
1129                 ceph_invalidate_dentry_lease(new_dentry);
1130         }
1131         ceph_mdsc_put_request(req);
1132         return err;
1133 }
1134
1135 /*
1136  * Ensure a dentry lease will no longer revalidate.
1137  */
1138 void ceph_invalidate_dentry_lease(struct dentry *dentry)
1139 {
1140         spin_lock(&dentry->d_lock);
1141         ceph_dentry(dentry)->time = jiffies;
1142         ceph_dentry(dentry)->lease_shared_gen = 0;
1143         spin_unlock(&dentry->d_lock);
1144 }
1145
1146 /*
1147  * Check if dentry lease is valid.  If not, delete the lease.  Try to
1148  * renew if the least is more than half up.
1149  */
1150 static int dentry_lease_is_valid(struct dentry *dentry, unsigned int flags,
1151                                  struct inode *dir)
1152 {
1153         struct ceph_dentry_info *di;
1154         struct ceph_mds_session *s;
1155         int valid = 0;
1156         u32 gen;
1157         unsigned long ttl;
1158         struct ceph_mds_session *session = NULL;
1159         u32 seq = 0;
1160
1161         spin_lock(&dentry->d_lock);
1162         di = ceph_dentry(dentry);
1163         if (di && di->lease_session) {
1164                 s = di->lease_session;
1165                 spin_lock(&s->s_gen_ttl_lock);
1166                 gen = s->s_cap_gen;
1167                 ttl = s->s_cap_ttl;
1168                 spin_unlock(&s->s_gen_ttl_lock);
1169
1170                 if (di->lease_gen == gen &&
1171                     time_before(jiffies, di->time) &&
1172                     time_before(jiffies, ttl)) {
1173                         valid = 1;
1174                         if (di->lease_renew_after &&
1175                             time_after(jiffies, di->lease_renew_after)) {
1176                                 /*
1177                                  * We should renew. If we're in RCU walk mode
1178                                  * though, we can't do that so just return
1179                                  * -ECHILD.
1180                                  */
1181                                 if (flags & LOOKUP_RCU) {
1182                                         valid = -ECHILD;
1183                                 } else {
1184                                         session = ceph_get_mds_session(s);
1185                                         seq = di->lease_seq;
1186                                         di->lease_renew_after = 0;
1187                                         di->lease_renew_from = jiffies;
1188                                 }
1189                         }
1190                 }
1191         }
1192         spin_unlock(&dentry->d_lock);
1193
1194         if (session) {
1195                 ceph_mdsc_lease_send_msg(session, dir, dentry,
1196                                          CEPH_MDS_LEASE_RENEW, seq);
1197                 ceph_put_mds_session(session);
1198         }
1199         dout("dentry_lease_is_valid - dentry %p = %d\n", dentry, valid);
1200         return valid;
1201 }
1202
1203 /*
1204  * Check if directory-wide content lease/cap is valid.
1205  */
1206 static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry)
1207 {
1208         struct ceph_inode_info *ci = ceph_inode(dir);
1209         struct ceph_dentry_info *di = ceph_dentry(dentry);
1210         int valid = 0;
1211
1212         spin_lock(&ci->i_ceph_lock);
1213         if (ci->i_shared_gen == di->lease_shared_gen)
1214                 valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
1215         spin_unlock(&ci->i_ceph_lock);
1216         dout("dir_lease_is_valid dir %p v%u dentry %p v%u = %d\n",
1217              dir, (unsigned)ci->i_shared_gen, dentry,
1218              (unsigned)di->lease_shared_gen, valid);
1219         return valid;
1220 }
1221
1222 /*
1223  * Check if cached dentry can be trusted.
1224  */
1225 static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
1226 {
1227         int valid = 0;
1228         struct dentry *parent;
1229         struct inode *dir;
1230
1231         if (flags & LOOKUP_RCU) {
1232                 parent = ACCESS_ONCE(dentry->d_parent);
1233                 dir = d_inode_rcu(parent);
1234                 if (!dir)
1235                         return -ECHILD;
1236         } else {
1237                 parent = dget_parent(dentry);
1238                 dir = d_inode(parent);
1239         }
1240
1241         dout("d_revalidate %p '%pd' inode %p offset %lld\n", dentry,
1242              dentry, d_inode(dentry), ceph_dentry(dentry)->offset);
1243
1244         /* always trust cached snapped dentries, snapdir dentry */
1245         if (ceph_snap(dir) != CEPH_NOSNAP) {
1246                 dout("d_revalidate %p '%pd' inode %p is SNAPPED\n", dentry,
1247                      dentry, d_inode(dentry));
1248                 valid = 1;
1249         } else if (d_really_is_positive(dentry) &&
1250                    ceph_snap(d_inode(dentry)) == CEPH_SNAPDIR) {
1251                 valid = 1;
1252         } else {
1253                 valid = dentry_lease_is_valid(dentry, flags, dir);
1254                 if (valid == -ECHILD)
1255                         return valid;
1256                 if (valid || dir_lease_is_valid(dir, dentry)) {
1257                         if (d_really_is_positive(dentry))
1258                                 valid = ceph_is_any_caps(d_inode(dentry));
1259                         else
1260                                 valid = 1;
1261                 }
1262         }
1263
1264         if (!valid) {
1265                 struct ceph_mds_client *mdsc =
1266                         ceph_sb_to_client(dir->i_sb)->mdsc;
1267                 struct ceph_mds_request *req;
1268                 int op, err;
1269                 u32 mask;
1270
1271                 if (flags & LOOKUP_RCU)
1272                         return -ECHILD;
1273
1274                 op = ceph_snap(dir) == CEPH_SNAPDIR ?
1275                         CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_GETATTR;
1276                 req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
1277                 if (!IS_ERR(req)) {
1278                         req->r_dentry = dget(dentry);
1279                         req->r_num_caps = op == CEPH_MDS_OP_GETATTR ? 1 : 2;
1280
1281                         mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
1282                         if (ceph_security_xattr_wanted(dir))
1283                                 mask |= CEPH_CAP_XATTR_SHARED;
1284                         req->r_args.getattr.mask = cpu_to_le32(mask);
1285
1286                         err = ceph_mdsc_do_request(mdsc, NULL, req);
1287                         switch (err) {
1288                         case 0:
1289                                 if (d_really_is_positive(dentry) &&
1290                                     d_inode(dentry) == req->r_target_inode)
1291                                         valid = 1;
1292                                 break;
1293                         case -ENOENT:
1294                                 if (d_really_is_negative(dentry))
1295                                         valid = 1;
1296                                 /* Fallthrough */
1297                         default:
1298                                 break;
1299                         }
1300                         ceph_mdsc_put_request(req);
1301                         dout("d_revalidate %p lookup result=%d\n",
1302                              dentry, err);
1303                 }
1304         }
1305
1306         dout("d_revalidate %p %s\n", dentry, valid ? "valid" : "invalid");
1307         if (valid) {
1308                 ceph_dentry_lru_touch(dentry);
1309         } else {
1310                 ceph_dir_clear_complete(dir);
1311         }
1312
1313         if (!(flags & LOOKUP_RCU))
1314                 dput(parent);
1315         return valid;
1316 }
1317
1318 /*
1319  * Release our ceph_dentry_info.
1320  */
1321 static void ceph_d_release(struct dentry *dentry)
1322 {
1323         struct ceph_dentry_info *di = ceph_dentry(dentry);
1324
1325         dout("d_release %p\n", dentry);
1326         ceph_dentry_lru_del(dentry);
1327
1328         spin_lock(&dentry->d_lock);
1329         dentry->d_fsdata = NULL;
1330         spin_unlock(&dentry->d_lock);
1331
1332         if (di->lease_session)
1333                 ceph_put_mds_session(di->lease_session);
1334         kmem_cache_free(ceph_dentry_cachep, di);
1335 }
1336
1337 static int ceph_snapdir_d_revalidate(struct dentry *dentry,
1338                                           unsigned int flags)
1339 {
1340         /*
1341          * Eventually, we'll want to revalidate snapped metadata
1342          * too... probably...
1343          */
1344         return 1;
1345 }
1346
1347 /*
1348  * When the VFS prunes a dentry from the cache, we need to clear the
1349  * complete flag on the parent directory.
1350  *
1351  * Called under dentry->d_lock.
1352  */
1353 static void ceph_d_prune(struct dentry *dentry)
1354 {
1355         dout("ceph_d_prune %p\n", dentry);
1356
1357         /* do we have a valid parent? */
1358         if (IS_ROOT(dentry))
1359                 return;
1360
1361         /* if we are not hashed, we don't affect dir's completeness */
1362         if (d_unhashed(dentry))
1363                 return;
1364
1365         /*
1366          * we hold d_lock, so d_parent is stable, and d_fsdata is never
1367          * cleared until d_release
1368          */
1369         ceph_dir_clear_complete(d_inode(dentry->d_parent));
1370 }
1371
1372 /*
1373  * read() on a dir.  This weird interface hack only works if mounted
1374  * with '-o dirstat'.
1375  */
1376 static ssize_t ceph_read_dir(struct file *file, char __user *buf, size_t size,
1377                              loff_t *ppos)
1378 {
1379         struct ceph_file_info *cf = file->private_data;
1380         struct inode *inode = file_inode(file);
1381         struct ceph_inode_info *ci = ceph_inode(inode);
1382         int left;
1383         const int bufsize = 1024;
1384
1385         if (!ceph_test_mount_opt(ceph_sb_to_client(inode->i_sb), DIRSTAT))
1386                 return -EISDIR;
1387
1388         if (!cf->dir_info) {
1389                 cf->dir_info = kmalloc(bufsize, GFP_KERNEL);
1390                 if (!cf->dir_info)
1391                         return -ENOMEM;
1392                 cf->dir_info_len =
1393                         snprintf(cf->dir_info, bufsize,
1394                                 "entries:   %20lld\n"
1395                                 " files:    %20lld\n"
1396                                 " subdirs:  %20lld\n"
1397                                 "rentries:  %20lld\n"
1398                                 " rfiles:   %20lld\n"
1399                                 " rsubdirs: %20lld\n"
1400                                 "rbytes:    %20lld\n"
1401                                 "rctime:    %10ld.%09ld\n",
1402                                 ci->i_files + ci->i_subdirs,
1403                                 ci->i_files,
1404                                 ci->i_subdirs,
1405                                 ci->i_rfiles + ci->i_rsubdirs,
1406                                 ci->i_rfiles,
1407                                 ci->i_rsubdirs,
1408                                 ci->i_rbytes,
1409                                 (long)ci->i_rctime.tv_sec,
1410                                 (long)ci->i_rctime.tv_nsec);
1411         }
1412
1413         if (*ppos >= cf->dir_info_len)
1414                 return 0;
1415         size = min_t(unsigned, size, cf->dir_info_len-*ppos);
1416         left = copy_to_user(buf, cf->dir_info + *ppos, size);
1417         if (left == size)
1418                 return -EFAULT;
1419         *ppos += (size - left);
1420         return size - left;
1421 }
1422
1423 /*
1424  * We maintain a private dentry LRU.
1425  *
1426  * FIXME: this needs to be changed to a per-mds lru to be useful.
1427  */
1428 void ceph_dentry_lru_add(struct dentry *dn)
1429 {
1430         struct ceph_dentry_info *di = ceph_dentry(dn);
1431         struct ceph_mds_client *mdsc;
1432
1433         dout("dentry_lru_add %p %p '%pd'\n", di, dn, dn);
1434         mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1435         spin_lock(&mdsc->dentry_lru_lock);
1436         list_add_tail(&di->lru, &mdsc->dentry_lru);
1437         mdsc->num_dentry++;
1438         spin_unlock(&mdsc->dentry_lru_lock);
1439 }
1440
1441 void ceph_dentry_lru_touch(struct dentry *dn)
1442 {
1443         struct ceph_dentry_info *di = ceph_dentry(dn);
1444         struct ceph_mds_client *mdsc;
1445
1446         dout("dentry_lru_touch %p %p '%pd' (offset %lld)\n", di, dn, dn,
1447              di->offset);
1448         mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1449         spin_lock(&mdsc->dentry_lru_lock);
1450         list_move_tail(&di->lru, &mdsc->dentry_lru);
1451         spin_unlock(&mdsc->dentry_lru_lock);
1452 }
1453
1454 void ceph_dentry_lru_del(struct dentry *dn)
1455 {
1456         struct ceph_dentry_info *di = ceph_dentry(dn);
1457         struct ceph_mds_client *mdsc;
1458
1459         dout("dentry_lru_del %p %p '%pd'\n", di, dn, dn);
1460         mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1461         spin_lock(&mdsc->dentry_lru_lock);
1462         list_del_init(&di->lru);
1463         mdsc->num_dentry--;
1464         spin_unlock(&mdsc->dentry_lru_lock);
1465 }
1466
1467 /*
1468  * Return name hash for a given dentry.  This is dependent on
1469  * the parent directory's hash function.
1470  */
1471 unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
1472 {
1473         struct ceph_inode_info *dci = ceph_inode(dir);
1474         unsigned hash;
1475
1476         switch (dci->i_dir_layout.dl_dir_hash) {
1477         case 0: /* for backward compat */
1478         case CEPH_STR_HASH_LINUX:
1479                 return dn->d_name.hash;
1480
1481         default:
1482                 spin_lock(&dn->d_lock);
1483                 hash = ceph_str_hash(dci->i_dir_layout.dl_dir_hash,
1484                                      dn->d_name.name, dn->d_name.len);
1485                 spin_unlock(&dn->d_lock);
1486                 return hash;
1487         }
1488 }
1489
1490 const struct file_operations ceph_dir_fops = {
1491         .read = ceph_read_dir,
1492         .iterate = ceph_readdir,
1493         .llseek = ceph_dir_llseek,
1494         .open = ceph_open,
1495         .release = ceph_release,
1496         .unlocked_ioctl = ceph_ioctl,
1497         .fsync = ceph_fsync,
1498 };
1499
1500 const struct file_operations ceph_snapdir_fops = {
1501         .iterate = ceph_readdir,
1502         .llseek = ceph_dir_llseek,
1503         .open = ceph_open,
1504         .release = ceph_release,
1505 };
1506
1507 const struct inode_operations ceph_dir_iops = {
1508         .lookup = ceph_lookup,
1509         .permission = ceph_permission,
1510         .getattr = ceph_getattr,
1511         .setattr = ceph_setattr,
1512         .listxattr = ceph_listxattr,
1513         .get_acl = ceph_get_acl,
1514         .set_acl = ceph_set_acl,
1515         .mknod = ceph_mknod,
1516         .symlink = ceph_symlink,
1517         .mkdir = ceph_mkdir,
1518         .link = ceph_link,
1519         .unlink = ceph_unlink,
1520         .rmdir = ceph_unlink,
1521         .rename = ceph_rename,
1522         .create = ceph_create,
1523         .atomic_open = ceph_atomic_open,
1524 };
1525
1526 const struct inode_operations ceph_snapdir_iops = {
1527         .lookup = ceph_lookup,
1528         .permission = ceph_permission,
1529         .getattr = ceph_getattr,
1530         .mkdir = ceph_mkdir,
1531         .rmdir = ceph_unlink,
1532         .rename = ceph_rename,
1533 };
1534
1535 const struct dentry_operations ceph_dentry_ops = {
1536         .d_revalidate = ceph_d_revalidate,
1537         .d_release = ceph_d_release,
1538         .d_prune = ceph_d_prune,
1539 };
1540
1541 const struct dentry_operations ceph_snapdir_dentry_ops = {
1542         .d_revalidate = ceph_snapdir_d_revalidate,
1543         .d_release = ceph_d_release,
1544 };
1545
1546 const struct dentry_operations ceph_snap_dentry_ops = {
1547         .d_release = ceph_d_release,
1548         .d_prune = ceph_d_prune,
1549 };