fs/ceph/dir.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/ceph/ceph_debug.h>
   3
   4 #include <linux/spinlock.h>
   5 #include <linux/fs_struct.h>
   6 #include <linux/namei.h>
   7 #include <linux/slab.h>
   8 #include <linux/sched.h>
   9 #include <linux/xattr.h>
  10
  11 #include "super.h"
  12 #include "mds_client.h"
  13
  14 /*
  15  * Directory operations: readdir, lookup, create, link, unlink,
  16  * rename, etc.
  17  */
  18
  19 /*
  20  * Ceph MDS operations are specified in terms of a base ino and
  21  * relative path.  Thus, the client can specify an operation on a
  22  * specific inode (e.g., a getattr due to fstat(2)), or as a path
  23  * relative to, say, the root directory.
  24  *
  25  * Normally, we limit ourselves to strict inode ops (no path component)
  26  * or dentry operations (a single path component relative to an ino).  The
  27  * exception to this is open_root_dentry(), which will open the mount
  28  * point by name.
  29  */
  30
  31 const struct dentry_operations ceph_dentry_ops;
  32
  33 /*
  34  * Initialize ceph dentry state.
  35  */
  36 static int ceph_d_init(struct dentry *dentry)
  37 {
  38         struct ceph_dentry_info *di;
  39
  40         di = kmem_cache_zalloc(ceph_dentry_cachep, GFP_KERNEL);
  41         if (!di)
  42                 return -ENOMEM;          /* oh well */
  43
  44         di->dentry = dentry;
  45         di->lease_session = NULL;
  46         di->time = jiffies;
  47         dentry->d_fsdata = di;
  48         ceph_dentry_lru_add(dentry);
  49         return 0;
  50 }
  51
  52 /*
  53  * for f_pos for readdir:
  54  * - hash order:
  55  *      (0xff << 52) | ((24 bits hash) << 28) |
  56  *      (the nth entry has hash collision);
  57  * - frag+name order;
  58  *      ((frag value) << 28) | (the nth entry in frag);
  59  */
  60 #define OFFSET_BITS     28
  61 #define OFFSET_MASK     ((1 << OFFSET_BITS) - 1)
  62 #define HASH_ORDER      (0xffull << (OFFSET_BITS + 24))
  63 loff_t ceph_make_fpos(unsigned high, unsigned off, bool hash_order)
  64 {
  65         loff_t fpos = ((loff_t)high << 28) | (loff_t)off;
  66         if (hash_order)
  67                 fpos |= HASH_ORDER;
  68         return fpos;
  69 }
  70
  71 static bool is_hash_order(loff_t p)
  72 {
  73         return (p & HASH_ORDER) == HASH_ORDER;
  74 }
  75
  76 static unsigned fpos_frag(loff_t p)
  77 {
  78         return p >> OFFSET_BITS;
  79 }
  80
  81 static unsigned fpos_hash(loff_t p)
  82 {
  83         return ceph_frag_value(fpos_frag(p));
  84 }
  85
  86 static unsigned fpos_off(loff_t p)
  87 {
  88         return p & OFFSET_MASK;
  89 }
  90
  91 static int fpos_cmp(loff_t l, loff_t r)
  92 {
  93         int v = ceph_frag_compare(fpos_frag(l), fpos_frag(r));
  94         if (v)
  95                 return v;
  96         return (int)(fpos_off(l) - fpos_off(r));
  97 }
  98
  99 /*
 100  * make note of the last dentry we read, so we can
 101  * continue at the same lexicographical point,
 102  * regardless of what dir changes take place on the
 103  * server.
 104  */
 105 static int note_last_dentry(struct ceph_file_info *fi, const char *name,
 106                             int len, unsigned next_offset)
 107 {
 108         char *buf = kmalloc(len+1, GFP_KERNEL);
 109         if (!buf)
 110                 return -ENOMEM;
 111         kfree(fi->last_name);
 112         fi->last_name = buf;
 113         memcpy(fi->last_name, name, len);
 114         fi->last_name[len] = 0;
 115         fi->next_offset = next_offset;
 116         dout("note_last_dentry '%s'\n", fi->last_name);
 117         return 0;
 118 }
 119
 120
 121 static struct dentry *
 122 __dcache_find_get_entry(struct dentry *parent, u64 idx,
 123                         struct ceph_readdir_cache_control *cache_ctl)
 124 {
 125         struct inode *dir = d_inode(parent);
 126         struct dentry *dentry;
 127         unsigned idx_mask = (PAGE_SIZE / sizeof(struct dentry *)) - 1;
 128         loff_t ptr_pos = idx * sizeof(struct dentry *);
 129         pgoff_t ptr_pgoff = ptr_pos >> PAGE_SHIFT;
 130
 131         if (ptr_pos >= i_size_read(dir))
 132                 return NULL;
 133
 134         if (!cache_ctl->page || ptr_pgoff != page_index(cache_ctl->page)) {
 135                 ceph_readdir_cache_release(cache_ctl);
 136                 cache_ctl->page = find_lock_page(&dir->i_data, ptr_pgoff);
 137                 if (!cache_ctl->page) {
 138                         dout(" page %lu not found\n", ptr_pgoff);
 139                         return ERR_PTR(-EAGAIN);
 140                 }
 141                 /* reading/filling the cache are serialized by
 142                    i_mutex, no need to use page lock */
 143                 unlock_page(cache_ctl->page);
 144                 cache_ctl->dentries = kmap(cache_ctl->page);
 145         }
 146
 147         cache_ctl->index = idx & idx_mask;
 148
 149         rcu_read_lock();
 150         spin_lock(&parent->d_lock);
 151         /* check i_size again here, because empty directory can be
 152          * marked as complete while not holding the i_mutex. */
 153         if (ceph_dir_is_complete_ordered(dir) && ptr_pos < i_size_read(dir))
 154                 dentry = cache_ctl->dentries[cache_ctl->index];
 155         else
 156                 dentry = NULL;
 157         spin_unlock(&parent->d_lock);
 158         if (dentry && !lockref_get_not_dead(&dentry->d_lockref))
 159                 dentry = NULL;
 160         rcu_read_unlock();
 161         return dentry ? : ERR_PTR(-EAGAIN);
 162 }
 163
 164 /*
 165  * When possible, we try to satisfy a readdir by peeking at the
 166  * dcache.  We make this work by carefully ordering dentries on
 167  * d_child when we initially get results back from the MDS, and
 168  * falling back to a "normal" sync readdir if any dentries in the dir
 169  * are dropped.
 170  *
 171  * Complete dir indicates that we have all dentries in the dir.  It is
 172  * defined IFF we hold CEPH_CAP_FILE_SHARED (which will be revoked by
 173  * the MDS if/when the directory is modified).
 174  */
 175 static int __dcache_readdir(struct file *file,  struct dir_context *ctx,
 176                             int shared_gen)
 177 {
 178         struct ceph_file_info *fi = file->private_data;
 179         struct dentry *parent = file->f_path.dentry;
 180         struct inode *dir = d_inode(parent);
 181         struct dentry *dentry, *last = NULL;
 182         struct ceph_dentry_info *di;
 183         struct ceph_readdir_cache_control cache_ctl = {};
 184         u64 idx = 0;
 185         int err = 0;
 186
 187         dout("__dcache_readdir %p v%u at %llx\n", dir, (unsigned)shared_gen, ctx->pos);
 188
 189         /* search start position */
 190         if (ctx->pos > 2) {
 191                 u64 count = div_u64(i_size_read(dir), sizeof(struct dentry *));
 192                 while (count > 0) {
 193                         u64 step = count >> 1;
 194                         dentry = __dcache_find_get_entry(parent, idx + step,
 195                                                          &cache_ctl);
 196                         if (!dentry) {
 197                                 /* use linar search */
 198                                 idx = 0;
 199                                 break;
 200                         }
 201                         if (IS_ERR(dentry)) {
 202                                 err = PTR_ERR(dentry);
 203                                 goto out;
 204                         }
 205                         di = ceph_dentry(dentry);
 206                         spin_lock(&dentry->d_lock);
 207                         if (fpos_cmp(di->offset, ctx->pos) < 0) {
 208                                 idx += step + 1;
 209                                 count -= step + 1;
 210                         } else {
 211                                 count = step;
 212                         }
 213                         spin_unlock(&dentry->d_lock);
 214                         dput(dentry);
 215                 }
 216
 217                 dout("__dcache_readdir %p cache idx %llu\n", dir, idx);
 218         }
 219
 220
 221         for (;;) {
 222                 bool emit_dentry = false;
 223                 dentry = __dcache_find_get_entry(parent, idx++, &cache_ctl);
 224                 if (!dentry) {
 225                         fi->flags |= CEPH_F_ATEND;
 226                         err = 0;
 227                         break;
 228                 }
 229                 if (IS_ERR(dentry)) {
 230                         err = PTR_ERR(dentry);
 231                         goto out;
 232                 }
 233
 234                 di = ceph_dentry(dentry);
 235                 spin_lock(&dentry->d_lock);
 236                 if (di->lease_shared_gen == shared_gen &&
 237                     d_really_is_positive(dentry) &&
 238                     fpos_cmp(ctx->pos, di->offset) <= 0) {
 239                         emit_dentry = true;
 240                 }
 241                 spin_unlock(&dentry->d_lock);
 242
 243                 if (emit_dentry) {
 244                         dout(" %llx dentry %p %pd %p\n", di->offset,
 245                              dentry, dentry, d_inode(dentry));
 246                         ctx->pos = di->offset;
 247                         if (!dir_emit(ctx, dentry->d_name.name,
 248                                       dentry->d_name.len,
 249                                       ceph_translate_ino(dentry->d_sb,
 250                                                          d_inode(dentry)->i_ino),
 251                                       d_inode(dentry)->i_mode >> 12)) {
 252                                 dput(dentry);
 253                                 err = 0;
 254                                 break;
 255                         }
 256                         ctx->pos++;
 257
 258                         if (last)
 259                                 dput(last);
 260                         last = dentry;
 261                 } else {
 262                         dput(dentry);
 263                 }
 264         }
 265 out:
 266         ceph_readdir_cache_release(&cache_ctl);
 267         if (last) {
 268                 int ret;
 269                 di = ceph_dentry(last);
 270                 ret = note_last_dentry(fi, last->d_name.name, last->d_name.len,
 271                                        fpos_off(di->offset) + 1);
 272                 if (ret < 0)
 273                         err = ret;
 274                 dput(last);
 275                 /* last_name no longer match cache index */
 276                 if (fi->readdir_cache_idx >= 0) {
 277                         fi->readdir_cache_idx = -1;
 278                         fi->dir_release_count = 0;
 279                 }
 280         }
 281         return err;
 282 }
 283
 284 static bool need_send_readdir(struct ceph_file_info *fi, loff_t pos)
 285 {
 286         if (!fi->last_readdir)
 287                 return true;
 288         if (is_hash_order(pos))
 289                 return !ceph_frag_contains_value(fi->frag, fpos_hash(pos));
 290         else
 291                 return fi->frag != fpos_frag(pos);
 292 }
 293
 294 static int ceph_readdir(struct file *file, struct dir_context *ctx)
 295 {
 296         struct ceph_file_info *fi = file->private_data;
 297         struct inode *inode = file_inode(file);
 298         struct ceph_inode_info *ci = ceph_inode(inode);
 299         struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
 300         struct ceph_mds_client *mdsc = fsc->mdsc;
 301         int i;
 302         int err;
 303         unsigned frag = -1;
 304         struct ceph_mds_reply_info_parsed *rinfo;
 305
 306         dout("readdir %p file %p pos %llx\n", inode, file, ctx->pos);
 307         if (fi->flags & CEPH_F_ATEND)
 308                 return 0;
 309
 310         /* always start with . and .. */
 311         if (ctx->pos == 0) {
 312                 dout("readdir off 0 -> '.'\n");
 313                 if (!dir_emit(ctx, ".", 1,
 314                             ceph_translate_ino(inode->i_sb, inode->i_ino),
 315                             inode->i_mode >> 12))
 316                         return 0;
 317                 ctx->pos = 1;
 318         }
 319         if (ctx->pos == 1) {
 320                 ino_t ino = parent_ino(file->f_path.dentry);
 321                 dout("readdir off 1 -> '..'\n");
 322                 if (!dir_emit(ctx, "..", 2,
 323                             ceph_translate_ino(inode->i_sb, ino),
 324                             inode->i_mode >> 12))
 325                         return 0;
 326                 ctx->pos = 2;
 327         }
 328
 329         /* can we use the dcache? */
 330         spin_lock(&ci->i_ceph_lock);
 331         if (ceph_test_mount_opt(fsc, DCACHE) &&
 332             !ceph_test_mount_opt(fsc, NOASYNCREADDIR) &&
 333             ceph_snap(inode) != CEPH_SNAPDIR &&
 334             __ceph_dir_is_complete_ordered(ci) &&
 335             __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1)) {
 336                 int shared_gen = atomic_read(&ci->i_shared_gen);
 337                 spin_unlock(&ci->i_ceph_lock);
 338                 err = __dcache_readdir(file, ctx, shared_gen);
 339                 if (err != -EAGAIN)
 340                         return err;
 341         } else {
 342                 spin_unlock(&ci->i_ceph_lock);
 343         }
 344
 345         /* proceed with a normal readdir */
 346 more:
 347         /* do we have the correct frag content buffered? */
 348         if (need_send_readdir(fi, ctx->pos)) {
 349                 struct ceph_mds_request *req;
 350                 int op = ceph_snap(inode) == CEPH_SNAPDIR ?
 351                         CEPH_MDS_OP_LSSNAP : CEPH_MDS_OP_READDIR;
 352
 353                 /* discard old result, if any */
 354                 if (fi->last_readdir) {
 355                         ceph_mdsc_put_request(fi->last_readdir);
 356                         fi->last_readdir = NULL;
 357                 }
 358
 359                 if (is_hash_order(ctx->pos)) {
 360                         /* fragtree isn't always accurate. choose frag
 361                          * based on previous reply when possible. */
 362                         if (frag == (unsigned)-1)
 363                                 frag = ceph_choose_frag(ci, fpos_hash(ctx->pos),
 364                                                         NULL, NULL);
 365                 } else {
 366                         frag = fpos_frag(ctx->pos);
 367                 }
 368
 369                 dout("readdir fetching %llx.%llx frag %x offset '%s'\n",
 370                      ceph_vinop(inode), frag, fi->last_name);
 371                 req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
 372                 if (IS_ERR(req))
 373                         return PTR_ERR(req);
 374                 err = ceph_alloc_readdir_reply_buffer(req, inode);
 375                 if (err) {
 376                         ceph_mdsc_put_request(req);
 377                         return err;
 378                 }
 379                 /* hints to request -> mds selection code */
 380                 req->r_direct_mode = USE_AUTH_MDS;
 381                 if (op == CEPH_MDS_OP_READDIR) {
 382                         req->r_direct_hash = ceph_frag_value(frag);
 383                         __set_bit(CEPH_MDS_R_DIRECT_IS_HASH, &req->r_req_flags);
 384                         req->r_inode_drop = CEPH_CAP_FILE_EXCL;
 385                 }
 386                 if (fi->last_name) {
 387                         req->r_path2 = kstrdup(fi->last_name, GFP_KERNEL);
 388                         if (!req->r_path2) {
 389                                 ceph_mdsc_put_request(req);
 390                                 return -ENOMEM;
 391                         }
 392                 } else if (is_hash_order(ctx->pos)) {
 393                         req->r_args.readdir.offset_hash =
 394                                 cpu_to_le32(fpos_hash(ctx->pos));
 395                 }
 396
 397                 req->r_dir_release_cnt = fi->dir_release_count;
 398                 req->r_dir_ordered_cnt = fi->dir_ordered_count;
 399                 req->r_readdir_cache_idx = fi->readdir_cache_idx;
 400                 req->r_readdir_offset = fi->next_offset;
 401                 req->r_args.readdir.frag = cpu_to_le32(frag);
 402                 req->r_args.readdir.flags =
 403                                 cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS);
 404
 405                 req->r_inode = inode;
 406                 ihold(inode);
 407                 req->r_dentry = dget(file->f_path.dentry);
 408                 err = ceph_mdsc_do_request(mdsc, NULL, req);
 409                 if (err < 0) {
 410                         ceph_mdsc_put_request(req);
 411                         return err;
 412                 }
 413                 dout("readdir got and parsed readdir result=%d on "
 414                      "frag %x, end=%d, complete=%d, hash_order=%d\n",
 415                      err, frag,
 416                      (int)req->r_reply_info.dir_end,
 417                      (int)req->r_reply_info.dir_complete,
 418                      (int)req->r_reply_info.hash_order);
 419
 420                 rinfo = &req->r_reply_info;
 421                 if (le32_to_cpu(rinfo->dir_dir->frag) != frag) {
 422                         frag = le32_to_cpu(rinfo->dir_dir->frag);
 423                         if (!rinfo->hash_order) {
 424                                 fi->next_offset = req->r_readdir_offset;
 425                                 /* adjust ctx->pos to beginning of frag */
 426                                 ctx->pos = ceph_make_fpos(frag,
 427                                                           fi->next_offset,
 428                                                           false);
 429                         }
 430                 }
 431
 432                 fi->frag = frag;
 433                 fi->last_readdir = req;
 434
 435                 if (test_bit(CEPH_MDS_R_DID_PREPOPULATE, &req->r_req_flags)) {
 436                         fi->readdir_cache_idx = req->r_readdir_cache_idx;
 437                         if (fi->readdir_cache_idx < 0) {
 438                                 /* preclude from marking dir ordered */
 439                                 fi->dir_ordered_count = 0;
 440                         } else if (ceph_frag_is_leftmost(frag) &&
 441                                    fi->next_offset == 2) {
 442                                 /* note dir version at start of readdir so
 443                                  * we can tell if any dentries get dropped */
 444                                 fi->dir_release_count = req->r_dir_release_cnt;
 445                                 fi->dir_ordered_count = req->r_dir_ordered_cnt;
 446                         }
 447                 } else {
 448                         dout("readdir !did_prepopulate");
 449                         /* disable readdir cache */
 450                         fi->readdir_cache_idx = -1;
 451                         /* preclude from marking dir complete */
 452                         fi->dir_release_count = 0;
 453                 }
 454
 455                 /* note next offset and last dentry name */
 456                 if (rinfo->dir_nr > 0) {
 457                         struct ceph_mds_reply_dir_entry *rde =
 458                                         rinfo->dir_entries + (rinfo->dir_nr-1);
 459                         unsigned next_offset = req->r_reply_info.dir_end ?
 460                                         2 : (fpos_off(rde->offset) + 1);
 461                         err = note_last_dentry(fi, rde->name, rde->name_len,
 462                                                next_offset);
 463                         if (err)
 464                                 return err;
 465                 } else if (req->r_reply_info.dir_end) {
 466                         fi->next_offset = 2;
 467                         /* keep last name */
 468                 }
 469         }
 470
 471         rinfo = &fi->last_readdir->r_reply_info;
 472         dout("readdir frag %x num %d pos %llx chunk first %llx\n",
 473              fi->frag, rinfo->dir_nr, ctx->pos,
 474              rinfo->dir_nr ? rinfo->dir_entries[0].offset : 0LL);
 475
 476         i = 0;
 477         /* search start position */
 478         if (rinfo->dir_nr > 0) {
 479                 int step, nr = rinfo->dir_nr;
 480                 while (nr > 0) {
 481                         step = nr >> 1;
 482                         if (rinfo->dir_entries[i + step].offset < ctx->pos) {
 483                                 i +=  step + 1;
 484                                 nr -= step + 1;
 485                         } else {
 486                                 nr = step;
 487                         }
 488                 }
 489         }
 490         for (; i < rinfo->dir_nr; i++) {
 491                 struct ceph_mds_reply_dir_entry *rde = rinfo->dir_entries + i;
 492                 struct ceph_vino vino;
 493                 ino_t ino;
 494                 u32 ftype;
 495
 496                 BUG_ON(rde->offset < ctx->pos);
 497
 498                 ctx->pos = rde->offset;
 499                 dout("readdir (%d/%d) -> %llx '%.*s' %p\n",
 500                      i, rinfo->dir_nr, ctx->pos,
 501                      rde->name_len, rde->name, &rde->inode.in);
 502
 503                 BUG_ON(!rde->inode.in);
 504                 ftype = le32_to_cpu(rde->inode.in->mode) >> 12;
 505                 vino.ino = le64_to_cpu(rde->inode.in->ino);
 506                 vino.snap = le64_to_cpu(rde->inode.in->snapid);
 507                 ino = ceph_vino_to_ino(vino);
 508
 509                 if (!dir_emit(ctx, rde->name, rde->name_len,
 510                               ceph_translate_ino(inode->i_sb, ino), ftype)) {
 511                         dout("filldir stopping us...\n");
 512                         return 0;
 513                 }
 514                 ctx->pos++;
 515         }
 516
 517         ceph_mdsc_put_request(fi->last_readdir);
 518         fi->last_readdir = NULL;
 519
 520         if (fi->next_offset > 2) {
 521                 frag = fi->frag;
 522                 goto more;
 523         }
 524
 525         /* more frags? */
 526         if (!ceph_frag_is_rightmost(fi->frag)) {
 527                 frag = ceph_frag_next(fi->frag);
 528                 if (is_hash_order(ctx->pos)) {
 529                         loff_t new_pos = ceph_make_fpos(ceph_frag_value(frag),
 530                                                         fi->next_offset, true);
 531                         if (new_pos > ctx->pos)
 532                                 ctx->pos = new_pos;
 533                         /* keep last_name */
 534                 } else {
 535                         ctx->pos = ceph_make_fpos(frag, fi->next_offset, false);
 536                         kfree(fi->last_name);
 537                         fi->last_name = NULL;
 538                 }
 539                 dout("readdir next frag is %x\n", frag);
 540                 goto more;
 541         }
 542         fi->flags |= CEPH_F_ATEND;
 543
 544         /*
 545          * if dir_release_count still matches the dir, no dentries
 546          * were released during the whole readdir, and we should have
 547          * the complete dir contents in our cache.
 548          */
 549         if (atomic64_read(&ci->i_release_count) == fi->dir_release_count) {
 550                 spin_lock(&ci->i_ceph_lock);
 551                 if (fi->dir_ordered_count == atomic64_read(&ci->i_ordered_count)) {
 552                         dout(" marking %p complete and ordered\n", inode);
 553                         /* use i_size to track number of entries in
 554                          * readdir cache */
 555                         BUG_ON(fi->readdir_cache_idx < 0);
 556                         i_size_write(inode, fi->readdir_cache_idx *
 557                                      sizeof(struct dentry*));
 558                 } else {
 559                         dout(" marking %p complete\n", inode);
 560                 }
 561                 __ceph_dir_set_complete(ci, fi->dir_release_count,
 562                                         fi->dir_ordered_count);
 563                 spin_unlock(&ci->i_ceph_lock);
 564         }
 565
 566         dout("readdir %p file %p done.\n", inode, file);
 567         return 0;
 568 }
 569
 570 static void reset_readdir(struct ceph_file_info *fi)
 571 {
 572         if (fi->last_readdir) {
 573                 ceph_mdsc_put_request(fi->last_readdir);
 574                 fi->last_readdir = NULL;
 575         }
 576         kfree(fi->last_name);
 577         fi->last_name = NULL;
 578         fi->dir_release_count = 0;
 579         fi->readdir_cache_idx = -1;
 580         fi->next_offset = 2;  /* compensate for . and .. */
 581         fi->flags &= ~CEPH_F_ATEND;
 582 }
 583
 584 /*
 585  * discard buffered readdir content on seekdir(0), or seek to new frag,
 586  * or seek prior to current chunk
 587  */
 588 static bool need_reset_readdir(struct ceph_file_info *fi, loff_t new_pos)
 589 {
 590         struct ceph_mds_reply_info_parsed *rinfo;
 591         loff_t chunk_offset;
 592         if (new_pos == 0)
 593                 return true;
 594         if (is_hash_order(new_pos)) {
 595                 /* no need to reset last_name for a forward seek when
 596                  * dentries are sotred in hash order */
 597         } else if (fi->frag != fpos_frag(new_pos)) {
 598                 return true;
 599         }
 600         rinfo = fi->last_readdir ? &fi->last_readdir->r_reply_info : NULL;
 601         if (!rinfo || !rinfo->dir_nr)
 602                 return true;
 603         chunk_offset = rinfo->dir_entries[0].offset;
 604         return new_pos < chunk_offset ||
 605                is_hash_order(new_pos) != is_hash_order(chunk_offset);
 606 }
 607
 608 static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int whence)
 609 {
 610         struct ceph_file_info *fi = file->private_data;
 611         struct inode *inode = file->f_mapping->host;
 612         loff_t retval;
 613
 614         inode_lock(inode);
 615         retval = -EINVAL;
 616         switch (whence) {
 617         case SEEK_CUR:
 618                 offset += file->f_pos;
 619         case SEEK_SET:
 620                 break;
 621         case SEEK_END:
 622                 retval = -EOPNOTSUPP;
 623         default:
 624                 goto out;
 625         }
 626
 627         if (offset >= 0) {
 628                 if (need_reset_readdir(fi, offset)) {
 629                         dout("dir_llseek dropping %p content\n", file);
 630                         reset_readdir(fi);
 631                 } else if (is_hash_order(offset) && offset > file->f_pos) {
 632                         /* for hash offset, we don't know if a forward seek
 633                          * is within same frag */
 634                         fi->dir_release_count = 0;
 635                         fi->readdir_cache_idx = -1;
 636                 }
 637
 638                 if (offset != file->f_pos) {
 639                         file->f_pos = offset;
 640                         file->f_version = 0;
 641                         fi->flags &= ~CEPH_F_ATEND;
 642                 }
 643                 retval = offset;
 644         }
 645 out:
 646         inode_unlock(inode);
 647         return retval;
 648 }
 649
 650 /*
 651  * Handle lookups for the hidden .snap directory.
 652  */
 653 int ceph_handle_snapdir(struct ceph_mds_request *req,
 654                         struct dentry *dentry, int err)
 655 {
 656         struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
 657         struct inode *parent = d_inode(dentry->d_parent); /* we hold i_mutex */
 658
 659         /* .snap dir? */
 660         if (err == -ENOENT &&
 661             ceph_snap(parent) == CEPH_NOSNAP &&
 662             strcmp(dentry->d_name.name,
 663                    fsc->mount_options->snapdir_name) == 0) {
 664                 struct inode *inode = ceph_get_snapdir(parent);
 665                 dout("ENOENT on snapdir %p '%pd', linking to snapdir %p\n",
 666                      dentry, dentry, inode);
 667                 BUG_ON(!d_unhashed(dentry));
 668                 d_add(dentry, inode);
 669                 err = 0;
 670         }
 671         return err;
 672 }
 673
 674 /*
 675  * Figure out final result of a lookup/open request.
 676  *
 677  * Mainly, make sure we return the final req->r_dentry (if it already
 678  * existed) in place of the original VFS-provided dentry when they
 679  * differ.
 680  *
 681  * Gracefully handle the case where the MDS replies with -ENOENT and
 682  * no trace (which it may do, at its discretion, e.g., if it doesn't
 683  * care to issue a lease on the negative dentry).
 684  */
 685 struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
 686                                   struct dentry *dentry, int err)
 687 {
 688         if (err == -ENOENT) {
 689                 /* no trace? */
 690                 err = 0;
 691                 if (!req->r_reply_info.head->is_dentry) {
 692                         dout("ENOENT and no trace, dentry %p inode %p\n",
 693                              dentry, d_inode(dentry));
 694                         if (d_really_is_positive(dentry)) {
 695                                 d_drop(dentry);
 696                                 err = -ENOENT;
 697                         } else {
 698                                 d_add(dentry, NULL);
 699                         }
 700                 }
 701         }
 702         if (err)
 703                 dentry = ERR_PTR(err);
 704         else if (dentry != req->r_dentry)
 705                 dentry = dget(req->r_dentry);   /* we got spliced */
 706         else
 707                 dentry = NULL;
 708         return dentry;
 709 }
 710
 711 static bool is_root_ceph_dentry(struct inode *inode, struct dentry *dentry)
 712 {
 713         return ceph_ino(inode) == CEPH_INO_ROOT &&
 714                 strncmp(dentry->d_name.name, ".ceph", 5) == 0;
 715 }
 716
 717 /*
 718  * Look up a single dir entry.  If there is a lookup intent, inform
 719  * the MDS so that it gets our 'caps wanted' value in a single op.
 720  */
 721 static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
 722                                   unsigned int flags)
 723 {
 724         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 725         struct ceph_mds_client *mdsc = fsc->mdsc;
 726         struct ceph_mds_request *req;
 727         int op;
 728         int mask;
 729         int err;
 730
 731         dout("lookup %p dentry %p '%pd'\n",
 732              dir, dentry, dentry);
 733
 734         if (dentry->d_name.len > NAME_MAX)
 735                 return ERR_PTR(-ENAMETOOLONG);
 736
 737         /* can we conclude ENOENT locally? */
 738         if (d_really_is_negative(dentry)) {
 739                 struct ceph_inode_info *ci = ceph_inode(dir);
 740                 struct ceph_dentry_info *di = ceph_dentry(dentry);
 741
 742                 spin_lock(&ci->i_ceph_lock);
 743                 dout(" dir %p flags are %d\n", dir, ci->i_ceph_flags);
 744                 if (strncmp(dentry->d_name.name,
 745                             fsc->mount_options->snapdir_name,
 746                             dentry->d_name.len) &&
 747                     !is_root_ceph_dentry(dir, dentry) &&
 748                     ceph_test_mount_opt(fsc, DCACHE) &&
 749                     __ceph_dir_is_complete(ci) &&
 750                     (__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1))) {
 751                         spin_unlock(&ci->i_ceph_lock);
 752                         dout(" dir %p complete, -ENOENT\n", dir);
 753                         d_add(dentry, NULL);
 754                         di->lease_shared_gen = atomic_read(&ci->i_shared_gen);
 755                         return NULL;
 756                 }
 757                 spin_unlock(&ci->i_ceph_lock);
 758         }
 759
 760         op = ceph_snap(dir) == CEPH_SNAPDIR ?
 761                 CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
 762         req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
 763         if (IS_ERR(req))
 764                 return ERR_CAST(req);
 765         req->r_dentry = dget(dentry);
 766         req->r_num_caps = 2;
 767
 768         mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
 769         if (ceph_security_xattr_wanted(dir))
 770                 mask |= CEPH_CAP_XATTR_SHARED;
 771         req->r_args.getattr.mask = cpu_to_le32(mask);
 772
 773         req->r_parent = dir;
 774         set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
 775         err = ceph_mdsc_do_request(mdsc, NULL, req);
 776         err = ceph_handle_snapdir(req, dentry, err);
 777         dentry = ceph_finish_lookup(req, dentry, err);
 778         ceph_mdsc_put_request(req);  /* will dput(dentry) */
 779         dout("lookup result=%p\n", dentry);
 780         return dentry;
 781 }
 782
 783 /*
 784  * If we do a create but get no trace back from the MDS, follow up with
 785  * a lookup (the VFS expects us to link up the provided dentry).
 786  */
 787 int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
 788 {
 789         struct dentry *result = ceph_lookup(dir, dentry, 0);
 790
 791         if (result && !IS_ERR(result)) {
 792                 /*
 793                  * We created the item, then did a lookup, and found
 794                  * it was already linked to another inode we already
 795                  * had in our cache (and thus got spliced). To not
 796                  * confuse VFS (especially when inode is a directory),
 797                  * we don't link our dentry to that inode, return an
 798                  * error instead.
 799                  *
 800                  * This event should be rare and it happens only when
 801                  * we talk to old MDS. Recent MDS does not send traceless
 802                  * reply for request that creates new inode.
 803                  */
 804                 d_drop(result);
 805                 return -ESTALE;
 806         }
 807         return PTR_ERR(result);
 808 }
 809
 810 static int ceph_mknod(struct inode *dir, struct dentry *dentry,
 811                       umode_t mode, dev_t rdev)
 812 {
 813         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 814         struct ceph_mds_client *mdsc = fsc->mdsc;
 815         struct ceph_mds_request *req;
 816         struct ceph_acls_info acls = {};
 817         int err;
 818
 819         if (ceph_snap(dir) != CEPH_NOSNAP)
 820                 return -EROFS;
 821
 822         err = ceph_pre_init_acls(dir, &mode, &acls);
 823         if (err < 0)
 824                 return err;
 825
 826         dout("mknod in dir %p dentry %p mode 0%ho rdev %d\n",
 827              dir, dentry, mode, rdev);
 828         req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_MKNOD, USE_AUTH_MDS);
 829         if (IS_ERR(req)) {
 830                 err = PTR_ERR(req);
 831                 goto out;
 832         }
 833         req->r_dentry = dget(dentry);
 834         req->r_num_caps = 2;
 835         req->r_parent = dir;
 836         set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
 837         req->r_args.mknod.mode = cpu_to_le32(mode);
 838         req->r_args.mknod.rdev = cpu_to_le32(rdev);
 839         req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
 840         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 841         if (acls.pagelist) {
 842                 req->r_pagelist = acls.pagelist;
 843                 acls.pagelist = NULL;
 844         }
 845         err = ceph_mdsc_do_request(mdsc, dir, req);
 846         if (!err && !req->r_reply_info.head->is_dentry)
 847                 err = ceph_handle_notrace_create(dir, dentry);
 848         ceph_mdsc_put_request(req);
 849 out:
 850         if (!err)
 851                 ceph_init_inode_acls(d_inode(dentry), &acls);
 852         else
 853                 d_drop(dentry);
 854         ceph_release_acls_info(&acls);
 855         return err;
 856 }
 857
 858 static int ceph_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 859                        bool excl)
 860 {
 861         return ceph_mknod(dir, dentry, mode, 0);
 862 }
 863
 864 static int ceph_symlink(struct inode *dir, struct dentry *dentry,
 865                             const char *dest)
 866 {
 867         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 868         struct ceph_mds_client *mdsc = fsc->mdsc;
 869         struct ceph_mds_request *req;
 870         int err;
 871
 872         if (ceph_snap(dir) != CEPH_NOSNAP)
 873                 return -EROFS;
 874
 875         dout("symlink in dir %p dentry %p to '%s'\n", dir, dentry, dest);
 876         req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SYMLINK, USE_AUTH_MDS);
 877         if (IS_ERR(req)) {
 878                 err = PTR_ERR(req);
 879                 goto out;
 880         }
 881         req->r_path2 = kstrdup(dest, GFP_KERNEL);
 882         if (!req->r_path2) {
 883                 err = -ENOMEM;
 884                 ceph_mdsc_put_request(req);
 885                 goto out;
 886         }
 887         req->r_parent = dir;
 888         set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
 889         req->r_dentry = dget(dentry);
 890         req->r_num_caps = 2;
 891         req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
 892         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 893         err = ceph_mdsc_do_request(mdsc, dir, req);
 894         if (!err && !req->r_reply_info.head->is_dentry)
 895                 err = ceph_handle_notrace_create(dir, dentry);
 896         ceph_mdsc_put_request(req);
 897 out:
 898         if (err)
 899                 d_drop(dentry);
 900         return err;
 901 }
 902
 903 static int ceph_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 904 {
 905         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 906         struct ceph_mds_client *mdsc = fsc->mdsc;
 907         struct ceph_mds_request *req;
 908         struct ceph_acls_info acls = {};
 909         int err = -EROFS;
 910         int op;
 911
 912         if (ceph_snap(dir) == CEPH_SNAPDIR) {
 913                 /* mkdir .snap/foo is a MKSNAP */
 914                 op = CEPH_MDS_OP_MKSNAP;
 915                 dout("mksnap dir %p snap '%pd' dn %p\n", dir,
 916                      dentry, dentry);
 917         } else if (ceph_snap(dir) == CEPH_NOSNAP) {
 918                 dout("mkdir dir %p dn %p mode 0%ho\n", dir, dentry, mode);
 919                 op = CEPH_MDS_OP_MKDIR;
 920         } else {
 921                 goto out;
 922         }
 923
 924         mode |= S_IFDIR;
 925         err = ceph_pre_init_acls(dir, &mode, &acls);
 926         if (err < 0)
 927                 goto out;
 928
 929         req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
 930         if (IS_ERR(req)) {
 931                 err = PTR_ERR(req);
 932                 goto out;
 933         }
 934
 935         req->r_dentry = dget(dentry);
 936         req->r_num_caps = 2;
 937         req->r_parent = dir;
 938         set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
 939         req->r_args.mkdir.mode = cpu_to_le32(mode);
 940         req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
 941         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 942         if (acls.pagelist) {
 943                 req->r_pagelist = acls.pagelist;
 944                 acls.pagelist = NULL;
 945         }
 946         err = ceph_mdsc_do_request(mdsc, dir, req);
 947         if (!err &&
 948             !req->r_reply_info.head->is_target &&
 949             !req->r_reply_info.head->is_dentry)
 950                 err = ceph_handle_notrace_create(dir, dentry);
 951         ceph_mdsc_put_request(req);
 952 out:
 953         if (!err)
 954                 ceph_init_inode_acls(d_inode(dentry), &acls);
 955         else
 956                 d_drop(dentry);
 957         ceph_release_acls_info(&acls);
 958         return err;
 959 }
 960
 961 static int ceph_link(struct dentry *old_dentry, struct inode *dir,
 962                      struct dentry *dentry)
 963 {
 964         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 965         struct ceph_mds_client *mdsc = fsc->mdsc;
 966         struct ceph_mds_request *req;
 967         int err;
 968
 969         if (ceph_snap(dir) != CEPH_NOSNAP)
 970                 return -EROFS;
 971
 972         dout("link in dir %p old_dentry %p dentry %p\n", dir,
 973              old_dentry, dentry);
 974         req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LINK, USE_AUTH_MDS);
 975         if (IS_ERR(req)) {
 976                 d_drop(dentry);
 977                 return PTR_ERR(req);
 978         }
 979         req->r_dentry = dget(dentry);
 980         req->r_num_caps = 2;
 981         req->r_old_dentry = dget(old_dentry);
 982         req->r_parent = dir;
 983         set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
 984         req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
 985         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 986         /* release LINK_SHARED on source inode (mds will lock it) */
 987         req->r_old_inode_drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
 988         err = ceph_mdsc_do_request(mdsc, dir, req);
 989         if (err) {
 990                 d_drop(dentry);
 991         } else if (!req->r_reply_info.head->is_dentry) {
 992                 ihold(d_inode(old_dentry));
 993                 d_instantiate(dentry, d_inode(old_dentry));
 994         }
 995         ceph_mdsc_put_request(req);
 996         return err;
 997 }
 998
 999 /*
1000  * For a soon-to-be unlinked file, drop the AUTH_RDCACHE caps.  If it
1001  * looks like the link count will hit 0, drop any other caps (other
1002  * than PIN) we don't specifically want (due to the file still being
1003  * open).
1004  */
1005 static int drop_caps_for_unlink(struct inode *inode)
1006 {
1007         struct ceph_inode_info *ci = ceph_inode(inode);
1008         int drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
1009
1010         spin_lock(&ci->i_ceph_lock);
1011         if (inode->i_nlink == 1) {
1012                 drop |= ~(__ceph_caps_wanted(ci) | CEPH_CAP_PIN);
1013                 ci->i_ceph_flags |= CEPH_I_NODELAY;
1014         }
1015         spin_unlock(&ci->i_ceph_lock);
1016         return drop;
1017 }
1018
1019 /*
1020  * rmdir and unlink are differ only by the metadata op code
1021  */
1022 static int ceph_unlink(struct inode *dir, struct dentry *dentry)
1023 {
1024         struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
1025         struct ceph_mds_client *mdsc = fsc->mdsc;
1026         struct inode *inode = d_inode(dentry);
1027         struct ceph_mds_request *req;
1028         int err = -EROFS;
1029         int op;
1030
1031         if (ceph_snap(dir) == CEPH_SNAPDIR) {
1032                 /* rmdir .snap/foo is RMSNAP */
1033                 dout("rmsnap dir %p '%pd' dn %p\n", dir, dentry, dentry);
1034                 op = CEPH_MDS_OP_RMSNAP;
1035         } else if (ceph_snap(dir) == CEPH_NOSNAP) {
1036                 dout("unlink/rmdir dir %p dn %p inode %p\n",
1037                      dir, dentry, inode);
1038                 op = d_is_dir(dentry) ?
1039                         CEPH_MDS_OP_RMDIR : CEPH_MDS_OP_UNLINK;
1040         } else
1041                 goto out;
1042         req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
1043         if (IS_ERR(req)) {
1044                 err = PTR_ERR(req);
1045                 goto out;
1046         }
1047         req->r_dentry = dget(dentry);
1048         req->r_num_caps = 2;
1049         req->r_parent = dir;
1050         set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
1051         req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
1052         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1053         req->r_inode_drop = drop_caps_for_unlink(inode);
1054         err = ceph_mdsc_do_request(mdsc, dir, req);
1055         if (!err && !req->r_reply_info.head->is_dentry)
1056                 d_delete(dentry);
1057         ceph_mdsc_put_request(req);
1058 out:
1059         return err;
1060 }
1061
1062 static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
1063                        struct inode *new_dir, struct dentry *new_dentry,
1064                        unsigned int flags)
1065 {
1066         struct ceph_fs_client *fsc = ceph_sb_to_client(old_dir->i_sb);
1067         struct ceph_mds_client *mdsc = fsc->mdsc;
1068         struct ceph_mds_request *req;
1069         int op = CEPH_MDS_OP_RENAME;
1070         int err;
1071
1072         if (flags)
1073                 return -EINVAL;
1074
1075         if (ceph_snap(old_dir) != ceph_snap(new_dir))
1076                 return -EXDEV;
1077         if (ceph_snap(old_dir) != CEPH_NOSNAP) {
1078                 if (old_dir == new_dir && ceph_snap(old_dir) == CEPH_SNAPDIR)
1079                         op = CEPH_MDS_OP_RENAMESNAP;
1080                 else
1081                         return -EROFS;
1082         }
1083         dout("rename dir %p dentry %p to dir %p dentry %p\n",
1084              old_dir, old_dentry, new_dir, new_dentry);
1085         req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
1086         if (IS_ERR(req))
1087                 return PTR_ERR(req);
1088         ihold(old_dir);
1089         req->r_dentry = dget(new_dentry);
1090         req->r_num_caps = 2;
1091         req->r_old_dentry = dget(old_dentry);
1092         req->r_old_dentry_dir = old_dir;
1093         req->r_parent = new_dir;
1094         set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
1095         req->r_old_dentry_drop = CEPH_CAP_FILE_SHARED;
1096         req->r_old_dentry_unless = CEPH_CAP_FILE_EXCL;
1097         req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
1098         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
1099         /* release LINK_RDCACHE on source inode (mds will lock it) */
1100         req->r_old_inode_drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
1101         if (d_really_is_positive(new_dentry))
1102                 req->r_inode_drop = drop_caps_for_unlink(d_inode(new_dentry));
1103         err = ceph_mdsc_do_request(mdsc, old_dir, req);
1104         if (!err && !req->r_reply_info.head->is_dentry) {
1105                 /*
1106                  * Normally d_move() is done by fill_trace (called by
1107                  * do_request, above).  If there is no trace, we need
1108                  * to do it here.
1109                  */
1110                 d_move(old_dentry, new_dentry);
1111         }
1112         ceph_mdsc_put_request(req);
1113         return err;
1114 }
1115
1116 /*
1117  * Ensure a dentry lease will no longer revalidate.
1118  */
1119 void ceph_invalidate_dentry_lease(struct dentry *dentry)
1120 {
1121         spin_lock(&dentry->d_lock);
1122         ceph_dentry(dentry)->time = jiffies;
1123         ceph_dentry(dentry)->lease_shared_gen = 0;
1124         spin_unlock(&dentry->d_lock);
1125 }
1126
1127 /*
1128  * Check if dentry lease is valid.  If not, delete the lease.  Try to
1129  * renew if the least is more than half up.
1130  */
1131 static int dentry_lease_is_valid(struct dentry *dentry, unsigned int flags,
1132                                  struct inode *dir)
1133 {
1134         struct ceph_dentry_info *di;
1135         struct ceph_mds_session *s;
1136         int valid = 0;
1137         u32 gen;
1138         unsigned long ttl;
1139         struct ceph_mds_session *session = NULL;
1140         u32 seq = 0;
1141
1142         spin_lock(&dentry->d_lock);
1143         di = ceph_dentry(dentry);
1144         if (di && di->lease_session) {
1145                 s = di->lease_session;
1146                 spin_lock(&s->s_gen_ttl_lock);
1147                 gen = s->s_cap_gen;
1148                 ttl = s->s_cap_ttl;
1149                 spin_unlock(&s->s_gen_ttl_lock);
1150
1151                 if (di->lease_gen == gen &&
1152                     time_before(jiffies, di->time) &&
1153                     time_before(jiffies, ttl)) {
1154                         valid = 1;
1155                         if (di->lease_renew_after &&
1156                             time_after(jiffies, di->lease_renew_after)) {
1157                                 /*
1158                                  * We should renew. If we're in RCU walk mode
1159                                  * though, we can't do that so just return
1160                                  * -ECHILD.
1161                                  */
1162                                 if (flags & LOOKUP_RCU) {
1163                                         valid = -ECHILD;
1164                                 } else {
1165                                         session = ceph_get_mds_session(s);
1166                                         seq = di->lease_seq;
1167                                         di->lease_renew_after = 0;
1168                                         di->lease_renew_from = jiffies;
1169                                 }
1170                         }
1171                 }
1172         }
1173         spin_unlock(&dentry->d_lock);
1174
1175         if (session) {
1176                 ceph_mdsc_lease_send_msg(session, dir, dentry,
1177                                          CEPH_MDS_LEASE_RENEW, seq);
1178                 ceph_put_mds_session(session);
1179         }
1180         dout("dentry_lease_is_valid - dentry %p = %d\n", dentry, valid);
1181         return valid;
1182 }
1183
1184 /*
1185  * Check if directory-wide content lease/cap is valid.
1186  */
1187 static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry)
1188 {
1189         struct ceph_inode_info *ci = ceph_inode(dir);
1190         struct ceph_dentry_info *di = ceph_dentry(dentry);
1191         int valid = 0;
1192
1193         spin_lock(&ci->i_ceph_lock);
1194         if (atomic_read(&ci->i_shared_gen) == di->lease_shared_gen)
1195                 valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
1196         spin_unlock(&ci->i_ceph_lock);
1197         dout("dir_lease_is_valid dir %p v%u dentry %p v%u = %d\n",
1198              dir, (unsigned)atomic_read(&ci->i_shared_gen),
1199              dentry, (unsigned)di->lease_shared_gen, valid);
1200         return valid;
1201 }
1202
1203 /*
1204  * Check if cached dentry can be trusted.
1205  */
1206 static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
1207 {
1208         int valid = 0;
1209         struct dentry *parent;
1210         struct inode *dir;
1211
1212         if (flags & LOOKUP_RCU) {
1213                 parent = READ_ONCE(dentry->d_parent);
1214                 dir = d_inode_rcu(parent);
1215                 if (!dir)
1216                         return -ECHILD;
1217         } else {
1218                 parent = dget_parent(dentry);
1219                 dir = d_inode(parent);
1220         }
1221
1222         dout("d_revalidate %p '%pd' inode %p offset %lld\n", dentry,
1223              dentry, d_inode(dentry), ceph_dentry(dentry)->offset);
1224
1225         /* always trust cached snapped dentries, snapdir dentry */
1226         if (ceph_snap(dir) != CEPH_NOSNAP) {
1227                 dout("d_revalidate %p '%pd' inode %p is SNAPPED\n", dentry,
1228                      dentry, d_inode(dentry));
1229                 valid = 1;
1230         } else if (d_really_is_positive(dentry) &&
1231                    ceph_snap(d_inode(dentry)) == CEPH_SNAPDIR) {
1232                 valid = 1;
1233         } else {
1234                 valid = dentry_lease_is_valid(dentry, flags, dir);
1235                 if (valid == -ECHILD)
1236                         return valid;
1237                 if (valid || dir_lease_is_valid(dir, dentry)) {
1238                         if (d_really_is_positive(dentry))
1239                                 valid = ceph_is_any_caps(d_inode(dentry));
1240                         else
1241                                 valid = 1;
1242                 }
1243         }
1244
1245         if (!valid) {
1246                 struct ceph_mds_client *mdsc =
1247                         ceph_sb_to_client(dir->i_sb)->mdsc;
1248                 struct ceph_mds_request *req;
1249                 int op, err;
1250                 u32 mask;
1251
1252                 if (flags & LOOKUP_RCU)
1253                         return -ECHILD;
1254
1255                 op = ceph_snap(dir) == CEPH_SNAPDIR ?
1256                         CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
1257                 req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
1258                 if (!IS_ERR(req)) {
1259                         req->r_dentry = dget(dentry);
1260                         req->r_num_caps = 2;
1261                         req->r_parent = dir;
1262
1263                         mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
1264                         if (ceph_security_xattr_wanted(dir))
1265                                 mask |= CEPH_CAP_XATTR_SHARED;
1266                         req->r_args.getattr.mask = cpu_to_le32(mask);
1267
1268                         err = ceph_mdsc_do_request(mdsc, NULL, req);
1269                         switch (err) {
1270                         case 0:
1271                                 if (d_really_is_positive(dentry) &&
1272                                     d_inode(dentry) == req->r_target_inode)
1273                                         valid = 1;
1274                                 break;
1275                         case -ENOENT:
1276                                 if (d_really_is_negative(dentry))
1277                                         valid = 1;
1278                                 /* Fallthrough */
1279                         default:
1280                                 break;
1281                         }
1282                         ceph_mdsc_put_request(req);
1283                         dout("d_revalidate %p lookup result=%d\n",
1284                              dentry, err);
1285                 }
1286         }
1287
1288         dout("d_revalidate %p %s\n", dentry, valid ? "valid" : "invalid");
1289         if (valid) {
1290                 ceph_dentry_lru_touch(dentry);
1291         } else {
1292                 ceph_dir_clear_complete(dir);
1293         }
1294
1295         if (!(flags & LOOKUP_RCU))
1296                 dput(parent);
1297         return valid;
1298 }
1299
1300 /*
1301  * Release our ceph_dentry_info.
1302  */
1303 static void ceph_d_release(struct dentry *dentry)
1304 {
1305         struct ceph_dentry_info *di = ceph_dentry(dentry);
1306
1307         dout("d_release %p\n", dentry);
1308         ceph_dentry_lru_del(dentry);
1309
1310         spin_lock(&dentry->d_lock);
1311         dentry->d_fsdata = NULL;
1312         spin_unlock(&dentry->d_lock);
1313
1314         if (di->lease_session)
1315                 ceph_put_mds_session(di->lease_session);
1316         kmem_cache_free(ceph_dentry_cachep, di);
1317 }
1318
1319 /*
1320  * When the VFS prunes a dentry from the cache, we need to clear the
1321  * complete flag on the parent directory.
1322  *
1323  * Called under dentry->d_lock.
1324  */
1325 static void ceph_d_prune(struct dentry *dentry)
1326 {
1327         dout("ceph_d_prune %p\n", dentry);
1328
1329         /* do we have a valid parent? */
1330         if (IS_ROOT(dentry))
1331                 return;
1332
1333         /* if we are not hashed, we don't affect dir's completeness */
1334         if (d_unhashed(dentry))
1335                 return;
1336
1337         if (ceph_snap(d_inode(dentry->d_parent)) == CEPH_SNAPDIR)
1338                 return;
1339
1340         /*
1341          * we hold d_lock, so d_parent is stable, and d_fsdata is never
1342          * cleared until d_release
1343          */
1344         ceph_dir_clear_complete(d_inode(dentry->d_parent));
1345 }
1346
1347 /*
1348  * read() on a dir.  This weird interface hack only works if mounted
1349  * with '-o dirstat'.
1350  */
1351 static ssize_t ceph_read_dir(struct file *file, char __user *buf, size_t size,
1352                              loff_t *ppos)
1353 {
1354         struct ceph_file_info *cf = file->private_data;
1355         struct inode *inode = file_inode(file);
1356         struct ceph_inode_info *ci = ceph_inode(inode);
1357         int left;
1358         const int bufsize = 1024;
1359
1360         if (!ceph_test_mount_opt(ceph_sb_to_client(inode->i_sb), DIRSTAT))
1361                 return -EISDIR;
1362
1363         if (!cf->dir_info) {
1364                 cf->dir_info = kmalloc(bufsize, GFP_KERNEL);
1365                 if (!cf->dir_info)
1366                         return -ENOMEM;
1367                 cf->dir_info_len =
1368                         snprintf(cf->dir_info, bufsize,
1369                                 "entries:   %20lld\n"
1370                                 " files:    %20lld\n"
1371                                 " subdirs:  %20lld\n"
1372                                 "rentries:  %20lld\n"
1373                                 " rfiles:   %20lld\n"
1374                                 " rsubdirs: %20lld\n"
1375                                 "rbytes:    %20lld\n"
1376                                 "rctime:    %10ld.%09ld\n",
1377                                 ci->i_files + ci->i_subdirs,
1378                                 ci->i_files,
1379                                 ci->i_subdirs,
1380                                 ci->i_rfiles + ci->i_rsubdirs,
1381                                 ci->i_rfiles,
1382                                 ci->i_rsubdirs,
1383                                 ci->i_rbytes,
1384                                 (long)ci->i_rctime.tv_sec,
1385                                 (long)ci->i_rctime.tv_nsec);
1386         }
1387
1388         if (*ppos >= cf->dir_info_len)
1389                 return 0;
1390         size = min_t(unsigned, size, cf->dir_info_len-*ppos);
1391         left = copy_to_user(buf, cf->dir_info + *ppos, size);
1392         if (left == size)
1393                 return -EFAULT;
1394         *ppos += (size - left);
1395         return size - left;
1396 }
1397
1398 /*
1399  * We maintain a private dentry LRU.
1400  *
1401  * FIXME: this needs to be changed to a per-mds lru to be useful.
1402  */
1403 void ceph_dentry_lru_add(struct dentry *dn)
1404 {
1405         struct ceph_dentry_info *di = ceph_dentry(dn);
1406         struct ceph_mds_client *mdsc;
1407
1408         dout("dentry_lru_add %p %p '%pd'\n", di, dn, dn);
1409         mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1410         spin_lock(&mdsc->dentry_lru_lock);
1411         list_add_tail(&di->lru, &mdsc->dentry_lru);
1412         mdsc->num_dentry++;
1413         spin_unlock(&mdsc->dentry_lru_lock);
1414 }
1415
1416 void ceph_dentry_lru_touch(struct dentry *dn)
1417 {
1418         struct ceph_dentry_info *di = ceph_dentry(dn);
1419         struct ceph_mds_client *mdsc;
1420
1421         dout("dentry_lru_touch %p %p '%pd' (offset %lld)\n", di, dn, dn,
1422              di->offset);
1423         mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1424         spin_lock(&mdsc->dentry_lru_lock);
1425         list_move_tail(&di->lru, &mdsc->dentry_lru);
1426         spin_unlock(&mdsc->dentry_lru_lock);
1427 }
1428
1429 void ceph_dentry_lru_del(struct dentry *dn)
1430 {
1431         struct ceph_dentry_info *di = ceph_dentry(dn);
1432         struct ceph_mds_client *mdsc;
1433
1434         dout("dentry_lru_del %p %p '%pd'\n", di, dn, dn);
1435         mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
1436         spin_lock(&mdsc->dentry_lru_lock);
1437         list_del_init(&di->lru);
1438         mdsc->num_dentry--;
1439         spin_unlock(&mdsc->dentry_lru_lock);
1440 }
1441
1442 /*
1443  * Return name hash for a given dentry.  This is dependent on
1444  * the parent directory's hash function.
1445  */
1446 unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
1447 {
1448         struct ceph_inode_info *dci = ceph_inode(dir);
1449
1450         switch (dci->i_dir_layout.dl_dir_hash) {
1451         case 0: /* for backward compat */
1452         case CEPH_STR_HASH_LINUX:
1453                 return dn->d_name.hash;
1454
1455         default:
1456                 return ceph_str_hash(dci->i_dir_layout.dl_dir_hash,
1457                                      dn->d_name.name, dn->d_name.len);
1458         }
1459 }
1460
1461 const struct file_operations ceph_dir_fops = {
1462         .read = ceph_read_dir,
1463         .iterate = ceph_readdir,
1464         .llseek = ceph_dir_llseek,
1465         .open = ceph_open,
1466         .release = ceph_release,
1467         .unlocked_ioctl = ceph_ioctl,
1468         .fsync = ceph_fsync,
1469 };
1470
1471 const struct file_operations ceph_snapdir_fops = {
1472         .iterate = ceph_readdir,
1473         .llseek = ceph_dir_llseek,
1474         .open = ceph_open,
1475         .release = ceph_release,
1476 };
1477
1478 const struct inode_operations ceph_dir_iops = {
1479         .lookup = ceph_lookup,
1480         .permission = ceph_permission,
1481         .getattr = ceph_getattr,
1482         .setattr = ceph_setattr,
1483         .listxattr = ceph_listxattr,
1484         .get_acl = ceph_get_acl,
1485         .set_acl = ceph_set_acl,
1486         .mknod = ceph_mknod,
1487         .symlink = ceph_symlink,
1488         .mkdir = ceph_mkdir,
1489         .link = ceph_link,
1490         .unlink = ceph_unlink,
1491         .rmdir = ceph_unlink,
1492         .rename = ceph_rename,
1493         .create = ceph_create,
1494         .atomic_open = ceph_atomic_open,
1495 };
1496
1497 const struct inode_operations ceph_snapdir_iops = {
1498         .lookup = ceph_lookup,
1499         .permission = ceph_permission,
1500         .getattr = ceph_getattr,
1501         .mkdir = ceph_mkdir,
1502         .rmdir = ceph_unlink,
1503         .rename = ceph_rename,
1504 };
1505
1506 const struct dentry_operations ceph_dentry_ops = {
1507         .d_revalidate = ceph_d_revalidate,
1508         .d_release = ceph_d_release,
1509         .d_prune = ceph_d_prune,
1510         .d_init = ceph_d_init,
1511 };