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