fs/ceph/super.c

   1
   2 #include <linux/ceph/ceph_debug.h>
   3
   4 #include <linux/backing-dev.h>
   5 #include <linux/ctype.h>
   6 #include <linux/fs.h>
   7 #include <linux/inet.h>
   8 #include <linux/in6.h>
   9 #include <linux/module.h>
  10 #include <linux/mount.h>
  11 #include <linux/parser.h>
  12 #include <linux/sched.h>
  13 #include <linux/seq_file.h>
  14 #include <linux/slab.h>
  15 #include <linux/statfs.h>
  16 #include <linux/string.h>
  17
  18 #include "super.h"
  19 #include "mds_client.h"
  20
  21 #include <linux/ceph/decode.h>
  22 #include <linux/ceph/mon_client.h>
  23 #include <linux/ceph/auth.h>
  24 #include <linux/ceph/debugfs.h>
  25
  26 /*
  27  * Ceph superblock operations
  28  *
  29  * Handle the basics of mounting, unmounting.
  30  */
  31
  32 /*
  33  * super ops
  34  */
  35 static void ceph_put_super(struct super_block *s)
  36 {
  37         struct ceph_fs_client *fsc = ceph_sb_to_client(s);
  38
  39         dout("put_super\n");
  40         ceph_mdsc_close_sessions(fsc->mdsc);
  41
  42         /*
  43          * ensure we release the bdi before put_anon_super releases
  44          * the device name.
  45          */
  46         if (s->s_bdi == &fsc->backing_dev_info) {
  47                 bdi_unregister(&fsc->backing_dev_info);
  48                 s->s_bdi = NULL;
  49         }
  50
  51         return;
  52 }
  53
  54 static int ceph_statfs(struct dentry *dentry, struct kstatfs *buf)
  55 {
  56         struct ceph_fs_client *fsc = ceph_inode_to_client(dentry->d_inode);
  57         struct ceph_monmap *monmap = fsc->client->monc.monmap;
  58         struct ceph_statfs st;
  59         u64 fsid;
  60         int err;
  61
  62         dout("statfs\n");
  63         err = ceph_monc_do_statfs(&fsc->client->monc, &st);
  64         if (err < 0)
  65                 return err;
  66
  67         /* fill in kstatfs */
  68         buf->f_type = CEPH_SUPER_MAGIC;  /* ?? */
  69
  70         /*
  71          * express utilization in terms of large blocks to avoid
  72          * overflow on 32-bit machines.
  73          */
  74         buf->f_bsize = 1 << CEPH_BLOCK_SHIFT;
  75         buf->f_blocks = le64_to_cpu(st.kb) >> (CEPH_BLOCK_SHIFT-10);
  76         buf->f_bfree = (le64_to_cpu(st.kb) - le64_to_cpu(st.kb_used)) >>
  77                 (CEPH_BLOCK_SHIFT-10);
  78         buf->f_bavail = le64_to_cpu(st.kb_avail) >> (CEPH_BLOCK_SHIFT-10);
  79
  80         buf->f_files = le64_to_cpu(st.num_objects);
  81         buf->f_ffree = -1;
  82         buf->f_namelen = NAME_MAX;
  83         buf->f_frsize = PAGE_CACHE_SIZE;
  84
  85         /* leave fsid little-endian, regardless of host endianness */
  86         fsid = *(u64 *)(&monmap->fsid) ^ *((u64 *)&monmap->fsid + 1);
  87         buf->f_fsid.val[0] = fsid & 0xffffffff;
  88         buf->f_fsid.val[1] = fsid >> 32;
  89
  90         return 0;
  91 }
  92
  93
  94 static int ceph_sync_fs(struct super_block *sb, int wait)
  95 {
  96         struct ceph_fs_client *fsc = ceph_sb_to_client(sb);
  97
  98         if (!wait) {
  99                 dout("sync_fs (non-blocking)\n");
 100                 ceph_flush_dirty_caps(fsc->mdsc);
 101                 dout("sync_fs (non-blocking) done\n");
 102                 return 0;
 103         }
 104
 105         dout("sync_fs (blocking)\n");
 106         ceph_osdc_sync(&fsc->client->osdc);
 107         ceph_mdsc_sync(fsc->mdsc);
 108         dout("sync_fs (blocking) done\n");
 109         return 0;
 110 }
 111
 112 /*
 113  * mount options
 114  */
 115 enum {
 116         Opt_wsize,
 117         Opt_rsize,
 118         Opt_caps_wanted_delay_min,
 119         Opt_caps_wanted_delay_max,
 120         Opt_cap_release_safety,
 121         Opt_readdir_max_entries,
 122         Opt_readdir_max_bytes,
 123         Opt_congestion_kb,
 124         Opt_last_int,
 125         /* int args above */
 126         Opt_snapdirname,
 127         Opt_last_string,
 128         /* string args above */
 129         Opt_dirstat,
 130         Opt_nodirstat,
 131         Opt_rbytes,
 132         Opt_norbytes,
 133         Opt_noasyncreaddir,
 134         Opt_ino32,
 135 };
 136
 137 static match_table_t fsopt_tokens = {
 138         {Opt_wsize, "wsize=%d"},
 139         {Opt_rsize, "rsize=%d"},
 140         {Opt_caps_wanted_delay_min, "caps_wanted_delay_min=%d"},
 141         {Opt_caps_wanted_delay_max, "caps_wanted_delay_max=%d"},
 142         {Opt_cap_release_safety, "cap_release_safety=%d"},
 143         {Opt_readdir_max_entries, "readdir_max_entries=%d"},
 144         {Opt_readdir_max_bytes, "readdir_max_bytes=%d"},
 145         {Opt_congestion_kb, "write_congestion_kb=%d"},
 146         /* int args above */
 147         {Opt_snapdirname, "snapdirname=%s"},
 148         /* string args above */
 149         {Opt_dirstat, "dirstat"},
 150         {Opt_nodirstat, "nodirstat"},
 151         {Opt_rbytes, "rbytes"},
 152         {Opt_norbytes, "norbytes"},
 153         {Opt_noasyncreaddir, "noasyncreaddir"},
 154         {Opt_ino32, "ino32"},
 155         {-1, NULL}
 156 };
 157
 158 static int parse_fsopt_token(char *c, void *private)
 159 {
 160         struct ceph_mount_options *fsopt = private;
 161         substring_t argstr[MAX_OPT_ARGS];
 162         int token, intval, ret;
 163
 164         token = match_token((char *)c, fsopt_tokens, argstr);
 165         if (token < 0)
 166                 return -EINVAL;
 167
 168         if (token < Opt_last_int) {
 169                 ret = match_int(&argstr[0], &intval);
 170                 if (ret < 0) {
 171                         pr_err("bad mount option arg (not int) "
 172                                "at '%s'\n", c);
 173                         return ret;
 174                 }
 175                 dout("got int token %d val %d\n", token, intval);
 176         } else if (token > Opt_last_int && token < Opt_last_string) {
 177                 dout("got string token %d val %s\n", token,
 178                      argstr[0].from);
 179         } else {
 180                 dout("got token %d\n", token);
 181         }
 182
 183         switch (token) {
 184         case Opt_snapdirname:
 185                 kfree(fsopt->snapdir_name);
 186                 fsopt->snapdir_name = kstrndup(argstr[0].from,
 187                                                argstr[0].to-argstr[0].from,
 188                                                GFP_KERNEL);
 189                 if (!fsopt->snapdir_name)
 190                         return -ENOMEM;
 191                 break;
 192
 193                 /* misc */
 194         case Opt_wsize:
 195                 fsopt->wsize = intval;
 196                 break;
 197         case Opt_rsize:
 198                 fsopt->rsize = intval;
 199                 break;
 200         case Opt_caps_wanted_delay_min:
 201                 fsopt->caps_wanted_delay_min = intval;
 202                 break;
 203         case Opt_caps_wanted_delay_max:
 204                 fsopt->caps_wanted_delay_max = intval;
 205                 break;
 206         case Opt_readdir_max_entries:
 207                 fsopt->max_readdir = intval;
 208                 break;
 209         case Opt_readdir_max_bytes:
 210                 fsopt->max_readdir_bytes = intval;
 211                 break;
 212         case Opt_congestion_kb:
 213                 fsopt->congestion_kb = intval;
 214                 break;
 215         case Opt_dirstat:
 216                 fsopt->flags |= CEPH_MOUNT_OPT_DIRSTAT;
 217                 break;
 218         case Opt_nodirstat:
 219                 fsopt->flags &= ~CEPH_MOUNT_OPT_DIRSTAT;
 220                 break;
 221         case Opt_rbytes:
 222                 fsopt->flags |= CEPH_MOUNT_OPT_RBYTES;
 223                 break;
 224         case Opt_norbytes:
 225                 fsopt->flags &= ~CEPH_MOUNT_OPT_RBYTES;
 226                 break;
 227         case Opt_noasyncreaddir:
 228                 fsopt->flags |= CEPH_MOUNT_OPT_NOASYNCREADDIR;
 229                 break;
 230         case Opt_ino32:
 231                 fsopt->flags |= CEPH_MOUNT_OPT_INO32;
 232                 break;
 233         default:
 234                 BUG_ON(token);
 235         }
 236         return 0;
 237 }
 238
 239 static void destroy_mount_options(struct ceph_mount_options *args)
 240 {
 241         dout("destroy_mount_options %p\n", args);
 242         kfree(args->snapdir_name);
 243         kfree(args);
 244 }
 245
 246 static int strcmp_null(const char *s1, const char *s2)
 247 {
 248         if (!s1 && !s2)
 249                 return 0;
 250         if (s1 && !s2)
 251                 return -1;
 252         if (!s1 && s2)
 253                 return 1;
 254         return strcmp(s1, s2);
 255 }
 256
 257 static int compare_mount_options(struct ceph_mount_options *new_fsopt,
 258                                  struct ceph_options *new_opt,
 259                                  struct ceph_fs_client *fsc)
 260 {
 261         struct ceph_mount_options *fsopt1 = new_fsopt;
 262         struct ceph_mount_options *fsopt2 = fsc->mount_options;
 263         int ofs = offsetof(struct ceph_mount_options, snapdir_name);
 264         int ret;
 265
 266         ret = memcmp(fsopt1, fsopt2, ofs);
 267         if (ret)
 268                 return ret;
 269
 270         ret = strcmp_null(fsopt1->snapdir_name, fsopt2->snapdir_name);
 271         if (ret)
 272                 return ret;
 273
 274         return ceph_compare_options(new_opt, fsc->client);
 275 }
 276
 277 static int parse_mount_options(struct ceph_mount_options **pfsopt,
 278                                struct ceph_options **popt,
 279                                int flags, char *options,
 280                                const char *dev_name,
 281                                const char **path)
 282 {
 283         struct ceph_mount_options *fsopt;
 284         const char *dev_name_end;
 285         int err = -ENOMEM;
 286
 287         fsopt = kzalloc(sizeof(*fsopt), GFP_KERNEL);
 288         if (!fsopt)
 289                 return -ENOMEM;
 290
 291         dout("parse_mount_options %p, dev_name '%s'\n", fsopt, dev_name);
 292
 293         fsopt->sb_flags = flags;
 294         fsopt->flags = CEPH_MOUNT_OPT_DEFAULT;
 295
 296         fsopt->rsize = CEPH_RSIZE_DEFAULT;
 297         fsopt->snapdir_name = kstrdup(CEPH_SNAPDIRNAME_DEFAULT, GFP_KERNEL);
 298         fsopt->caps_wanted_delay_min = CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT;
 299         fsopt->caps_wanted_delay_max = CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT;
 300         fsopt->cap_release_safety = CEPH_CAP_RELEASE_SAFETY_DEFAULT;
 301         fsopt->max_readdir = CEPH_MAX_READDIR_DEFAULT;
 302         fsopt->max_readdir_bytes = CEPH_MAX_READDIR_BYTES_DEFAULT;
 303         fsopt->congestion_kb = default_congestion_kb();
 304
 305         /* ip1[:port1][,ip2[:port2]...]:/subdir/in/fs */
 306         err = -EINVAL;
 307         if (!dev_name)
 308                 goto out;
 309         *path = strstr(dev_name, ":/");
 310         if (*path == NULL) {
 311                 pr_err("device name is missing path (no :/ in %s)\n",
 312                        dev_name);
 313                 goto out;
 314         }
 315         dev_name_end = *path;
 316         dout("device name '%.*s'\n", (int)(dev_name_end - dev_name), dev_name);
 317
 318         /* path on server */
 319         *path += 2;
 320         dout("server path '%s'\n", *path);
 321
 322         err = ceph_parse_options(popt, options, dev_name, dev_name_end,
 323                                  parse_fsopt_token, (void *)fsopt);
 324         if (err)
 325                 goto out;
 326
 327         /* success */
 328         *pfsopt = fsopt;
 329         return 0;
 330
 331 out:
 332         destroy_mount_options(fsopt);
 333         return err;
 334 }
 335
 336 /**
 337  * ceph_show_options - Show mount options in /proc/mounts
 338  * @m: seq_file to write to
 339  * @mnt: mount descriptor
 340  */
 341 static int ceph_show_options(struct seq_file *m, struct vfsmount *mnt)
 342 {
 343         struct ceph_fs_client *fsc = ceph_sb_to_client(mnt->mnt_sb);
 344         struct ceph_mount_options *fsopt = fsc->mount_options;
 345         struct ceph_options *opt = fsc->client->options;
 346
 347         if (opt->flags & CEPH_OPT_FSID)
 348                 seq_printf(m, ",fsid=%pU", &opt->fsid);
 349         if (opt->flags & CEPH_OPT_NOSHARE)
 350                 seq_puts(m, ",noshare");
 351         if (opt->flags & CEPH_OPT_NOCRC)
 352                 seq_puts(m, ",nocrc");
 353
 354         if (opt->name)
 355                 seq_printf(m, ",name=%s", opt->name);
 356         if (opt->key)
 357                 seq_puts(m, ",secret=<hidden>");
 358
 359         if (opt->mount_timeout != CEPH_MOUNT_TIMEOUT_DEFAULT)
 360                 seq_printf(m, ",mount_timeout=%d", opt->mount_timeout);
 361         if (opt->osd_idle_ttl != CEPH_OSD_IDLE_TTL_DEFAULT)
 362                 seq_printf(m, ",osd_idle_ttl=%d", opt->osd_idle_ttl);
 363         if (opt->osd_timeout != CEPH_OSD_TIMEOUT_DEFAULT)
 364                 seq_printf(m, ",osdtimeout=%d", opt->osd_timeout);
 365         if (opt->osd_keepalive_timeout != CEPH_OSD_KEEPALIVE_DEFAULT)
 366                 seq_printf(m, ",osdkeepalivetimeout=%d",
 367                            opt->osd_keepalive_timeout);
 368
 369         if (fsopt->flags & CEPH_MOUNT_OPT_DIRSTAT)
 370                 seq_puts(m, ",dirstat");
 371         if ((fsopt->flags & CEPH_MOUNT_OPT_RBYTES) == 0)
 372                 seq_puts(m, ",norbytes");
 373         if (fsopt->flags & CEPH_MOUNT_OPT_NOASYNCREADDIR)
 374                 seq_puts(m, ",noasyncreaddir");
 375
 376         if (fsopt->wsize)
 377                 seq_printf(m, ",wsize=%d", fsopt->wsize);
 378         if (fsopt->rsize != CEPH_RSIZE_DEFAULT)
 379                 seq_printf(m, ",rsize=%d", fsopt->rsize);
 380         if (fsopt->congestion_kb != default_congestion_kb())
 381                 seq_printf(m, ",write_congestion_kb=%d", fsopt->congestion_kb);
 382         if (fsopt->caps_wanted_delay_min != CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT)
 383                 seq_printf(m, ",caps_wanted_delay_min=%d",
 384                          fsopt->caps_wanted_delay_min);
 385         if (fsopt->caps_wanted_delay_max != CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT)
 386                 seq_printf(m, ",caps_wanted_delay_max=%d",
 387                            fsopt->caps_wanted_delay_max);
 388         if (fsopt->cap_release_safety != CEPH_CAP_RELEASE_SAFETY_DEFAULT)
 389                 seq_printf(m, ",cap_release_safety=%d",
 390                            fsopt->cap_release_safety);
 391         if (fsopt->max_readdir != CEPH_MAX_READDIR_DEFAULT)
 392                 seq_printf(m, ",readdir_max_entries=%d", fsopt->max_readdir);
 393         if (fsopt->max_readdir_bytes != CEPH_MAX_READDIR_BYTES_DEFAULT)
 394                 seq_printf(m, ",readdir_max_bytes=%d", fsopt->max_readdir_bytes);
 395         if (strcmp(fsopt->snapdir_name, CEPH_SNAPDIRNAME_DEFAULT))
 396                 seq_printf(m, ",snapdirname=%s", fsopt->snapdir_name);
 397         return 0;
 398 }
 399
 400 /*
 401  * handle any mon messages the standard library doesn't understand.
 402  * return error if we don't either.
 403  */
 404 static int extra_mon_dispatch(struct ceph_client *client, struct ceph_msg *msg)
 405 {
 406         struct ceph_fs_client *fsc = client->private;
 407         int type = le16_to_cpu(msg->hdr.type);
 408
 409         switch (type) {
 410         case CEPH_MSG_MDS_MAP:
 411                 ceph_mdsc_handle_map(fsc->mdsc, msg);
 412                 return 0;
 413
 414         default:
 415                 return -1;
 416         }
 417 }
 418
 419 /*
 420  * create a new fs client
 421  */
 422 struct ceph_fs_client *create_fs_client(struct ceph_mount_options *fsopt,
 423                                         struct ceph_options *opt)
 424 {
 425         struct ceph_fs_client *fsc;
 426         int err = -ENOMEM;
 427
 428         fsc = kzalloc(sizeof(*fsc), GFP_KERNEL);
 429         if (!fsc)
 430                 return ERR_PTR(-ENOMEM);
 431
 432         fsc->client = ceph_create_client(opt, fsc);
 433         if (IS_ERR(fsc->client)) {
 434                 err = PTR_ERR(fsc->client);
 435                 goto fail;
 436         }
 437         fsc->client->extra_mon_dispatch = extra_mon_dispatch;
 438         fsc->client->supported_features |= CEPH_FEATURE_FLOCK |
 439                 CEPH_FEATURE_DIRLAYOUTHASH;
 440         fsc->client->monc.want_mdsmap = 1;
 441
 442         fsc->mount_options = fsopt;
 443
 444         fsc->sb = NULL;
 445         fsc->mount_state = CEPH_MOUNT_MOUNTING;
 446
 447         atomic_long_set(&fsc->writeback_count, 0);
 448
 449         err = bdi_init(&fsc->backing_dev_info);
 450         if (err < 0)
 451                 goto fail_client;
 452
 453         err = -ENOMEM;
 454         /*
 455          * The number of concurrent works can be high but they don't need
 456          * to be processed in parallel, limit concurrency.
 457          */
 458         fsc->wb_wq = alloc_workqueue("ceph-writeback", 0, 1);
 459         if (fsc->wb_wq == NULL)
 460                 goto fail_bdi;
 461         fsc->pg_inv_wq = alloc_workqueue("ceph-pg-invalid", 0, 1);
 462         if (fsc->pg_inv_wq == NULL)
 463                 goto fail_wb_wq;
 464         fsc->trunc_wq = alloc_workqueue("ceph-trunc", 0, 1);
 465         if (fsc->trunc_wq == NULL)
 466                 goto fail_pg_inv_wq;
 467
 468         /* set up mempools */
 469         err = -ENOMEM;
 470         fsc->wb_pagevec_pool = mempool_create_kmalloc_pool(10,
 471                               fsc->mount_options->wsize >> PAGE_CACHE_SHIFT);
 472         if (!fsc->wb_pagevec_pool)
 473                 goto fail_trunc_wq;
 474
 475         /* caps */
 476         fsc->min_caps = fsopt->max_readdir;
 477
 478         return fsc;
 479
 480 fail_trunc_wq:
 481         destroy_workqueue(fsc->trunc_wq);
 482 fail_pg_inv_wq:
 483         destroy_workqueue(fsc->pg_inv_wq);
 484 fail_wb_wq:
 485         destroy_workqueue(fsc->wb_wq);
 486 fail_bdi:
 487         bdi_destroy(&fsc->backing_dev_info);
 488 fail_client:
 489         ceph_destroy_client(fsc->client);
 490 fail:
 491         kfree(fsc);
 492         return ERR_PTR(err);
 493 }
 494
 495 void destroy_fs_client(struct ceph_fs_client *fsc)
 496 {
 497         dout("destroy_fs_client %p\n", fsc);
 498
 499         destroy_workqueue(fsc->wb_wq);
 500         destroy_workqueue(fsc->pg_inv_wq);
 501         destroy_workqueue(fsc->trunc_wq);
 502
 503         bdi_destroy(&fsc->backing_dev_info);
 504
 505         mempool_destroy(fsc->wb_pagevec_pool);
 506
 507         destroy_mount_options(fsc->mount_options);
 508
 509         ceph_fs_debugfs_cleanup(fsc);
 510
 511         ceph_destroy_client(fsc->client);
 512
 513         kfree(fsc);
 514         dout("destroy_fs_client %p done\n", fsc);
 515 }
 516
 517 /*
 518  * caches
 519  */
 520 struct kmem_cache *ceph_inode_cachep;
 521 struct kmem_cache *ceph_cap_cachep;
 522 struct kmem_cache *ceph_dentry_cachep;
 523 struct kmem_cache *ceph_file_cachep;
 524
 525 static void ceph_inode_init_once(void *foo)
 526 {
 527         struct ceph_inode_info *ci = foo;
 528         inode_init_once(&ci->vfs_inode);
 529 }
 530
 531 static int __init init_caches(void)
 532 {
 533         ceph_inode_cachep = kmem_cache_create("ceph_inode_info",
 534                                       sizeof(struct ceph_inode_info),
 535                                       __alignof__(struct ceph_inode_info),
 536                                       (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD),
 537                                       ceph_inode_init_once);
 538         if (ceph_inode_cachep == NULL)
 539                 return -ENOMEM;
 540
 541         ceph_cap_cachep = KMEM_CACHE(ceph_cap,
 542                                      SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
 543         if (ceph_cap_cachep == NULL)
 544                 goto bad_cap;
 545
 546         ceph_dentry_cachep = KMEM_CACHE(ceph_dentry_info,
 547                                         SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
 548         if (ceph_dentry_cachep == NULL)
 549                 goto bad_dentry;
 550
 551         ceph_file_cachep = KMEM_CACHE(ceph_file_info,
 552                                       SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
 553         if (ceph_file_cachep == NULL)
 554                 goto bad_file;
 555
 556         return 0;
 557
 558 bad_file:
 559         kmem_cache_destroy(ceph_dentry_cachep);
 560 bad_dentry:
 561         kmem_cache_destroy(ceph_cap_cachep);
 562 bad_cap:
 563         kmem_cache_destroy(ceph_inode_cachep);
 564         return -ENOMEM;
 565 }
 566
 567 static void destroy_caches(void)
 568 {
 569         kmem_cache_destroy(ceph_inode_cachep);
 570         kmem_cache_destroy(ceph_cap_cachep);
 571         kmem_cache_destroy(ceph_dentry_cachep);
 572         kmem_cache_destroy(ceph_file_cachep);
 573 }
 574
 575
 576 /*
 577  * ceph_umount_begin - initiate forced umount.  Tear down down the
 578  * mount, skipping steps that may hang while waiting for server(s).
 579  */
 580 static void ceph_umount_begin(struct super_block *sb)
 581 {
 582         struct ceph_fs_client *fsc = ceph_sb_to_client(sb);
 583
 584         dout("ceph_umount_begin - starting forced umount\n");
 585         if (!fsc)
 586                 return;
 587         fsc->mount_state = CEPH_MOUNT_SHUTDOWN;
 588         return;
 589 }
 590
 591 static const struct super_operations ceph_super_ops = {
 592         .alloc_inode    = ceph_alloc_inode,
 593         .destroy_inode  = ceph_destroy_inode,
 594         .write_inode    = ceph_write_inode,
 595         .sync_fs        = ceph_sync_fs,
 596         .put_super      = ceph_put_super,
 597         .show_options   = ceph_show_options,
 598         .statfs         = ceph_statfs,
 599         .umount_begin   = ceph_umount_begin,
 600 };
 601
 602 /*
 603  * Bootstrap mount by opening the root directory.  Note the mount
 604  * @started time from caller, and time out if this takes too long.
 605  */
 606 static struct dentry *open_root_dentry(struct ceph_fs_client *fsc,
 607                                        const char *path,
 608                                        unsigned long started)
 609 {
 610         struct ceph_mds_client *mdsc = fsc->mdsc;
 611         struct ceph_mds_request *req = NULL;
 612         int err;
 613         struct dentry *root;
 614
 615         /* open dir */
 616         dout("open_root_inode opening '%s'\n", path);
 617         req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_GETATTR, USE_ANY_MDS);
 618         if (IS_ERR(req))
 619                 return ERR_CAST(req);
 620         req->r_path1 = kstrdup(path, GFP_NOFS);
 621         req->r_ino1.ino = CEPH_INO_ROOT;
 622         req->r_ino1.snap = CEPH_NOSNAP;
 623         req->r_started = started;
 624         req->r_timeout = fsc->client->options->mount_timeout * HZ;
 625         req->r_args.getattr.mask = cpu_to_le32(CEPH_STAT_CAP_INODE);
 626         req->r_num_caps = 2;
 627         err = ceph_mdsc_do_request(mdsc, NULL, req);
 628         if (err == 0) {
 629                 dout("open_root_inode success\n");
 630                 if (ceph_ino(req->r_target_inode) == CEPH_INO_ROOT &&
 631                     fsc->sb->s_root == NULL)
 632                         root = d_alloc_root(req->r_target_inode);
 633                 else
 634                         root = d_obtain_alias(req->r_target_inode);
 635                 req->r_target_inode = NULL;
 636                 dout("open_root_inode success, root dentry is %p\n", root);
 637         } else {
 638                 root = ERR_PTR(err);
 639         }
 640         ceph_mdsc_put_request(req);
 641         return root;
 642 }
 643
 644
 645
 646
 647 /*
 648  * mount: join the ceph cluster, and open root directory.
 649  */
 650 static struct dentry *ceph_real_mount(struct ceph_fs_client *fsc,
 651                       const char *path)
 652 {
 653         int err;
 654         unsigned long started = jiffies;  /* note the start time */
 655         struct dentry *root;
 656         int first = 0;   /* first vfsmount for this super_block */
 657
 658         dout("mount start\n");
 659         mutex_lock(&fsc->client->mount_mutex);
 660
 661         err = __ceph_open_session(fsc->client, started);
 662         if (err < 0)
 663                 goto out;
 664
 665         dout("mount opening root\n");
 666         root = open_root_dentry(fsc, "", started);
 667         if (IS_ERR(root)) {
 668                 err = PTR_ERR(root);
 669                 goto out;
 670         }
 671         if (fsc->sb->s_root) {
 672                 dput(root);
 673         } else {
 674                 fsc->sb->s_root = root;
 675                 first = 1;
 676
 677                 err = ceph_fs_debugfs_init(fsc);
 678                 if (err < 0)
 679                         goto fail;
 680         }
 681
 682         if (path[0] == 0) {
 683                 dget(root);
 684         } else {
 685                 dout("mount opening base mountpoint\n");
 686                 root = open_root_dentry(fsc, path, started);
 687                 if (IS_ERR(root)) {
 688                         err = PTR_ERR(root);
 689                         goto fail;
 690                 }
 691         }
 692
 693         fsc->mount_state = CEPH_MOUNT_MOUNTED;
 694         dout("mount success\n");
 695         mutex_unlock(&fsc->client->mount_mutex);
 696         return root;
 697
 698 out:
 699         mutex_unlock(&fsc->client->mount_mutex);
 700         return ERR_PTR(err);
 701
 702 fail:
 703         if (first) {
 704                 dput(fsc->sb->s_root);
 705                 fsc->sb->s_root = NULL;
 706         }
 707         goto out;
 708 }
 709
 710 static int ceph_set_super(struct super_block *s, void *data)
 711 {
 712         struct ceph_fs_client *fsc = data;
 713         int ret;
 714
 715         dout("set_super %p data %p\n", s, data);
 716
 717         s->s_flags = fsc->mount_options->sb_flags;
 718         s->s_maxbytes = 1ULL << 40;  /* temp value until we get mdsmap */
 719
 720         s->s_fs_info = fsc;
 721         fsc->sb = s;
 722
 723         s->s_op = &ceph_super_ops;
 724         s->s_export_op = &ceph_export_ops;
 725
 726         s->s_time_gran = 1000;  /* 1000 ns == 1 us */
 727
 728         ret = set_anon_super(s, NULL);  /* what is that second arg for? */
 729         if (ret != 0)
 730                 goto fail;
 731
 732         return ret;
 733
 734 fail:
 735         s->s_fs_info = NULL;
 736         fsc->sb = NULL;
 737         return ret;
 738 }
 739
 740 /*
 741  * share superblock if same fs AND options
 742  */
 743 static int ceph_compare_super(struct super_block *sb, void *data)
 744 {
 745         struct ceph_fs_client *new = data;
 746         struct ceph_mount_options *fsopt = new->mount_options;
 747         struct ceph_options *opt = new->client->options;
 748         struct ceph_fs_client *other = ceph_sb_to_client(sb);
 749
 750         dout("ceph_compare_super %p\n", sb);
 751
 752         if (compare_mount_options(fsopt, opt, other)) {
 753                 dout("monitor(s)/mount options don't match\n");
 754                 return 0;
 755         }
 756         if ((opt->flags & CEPH_OPT_FSID) &&
 757             ceph_fsid_compare(&opt->fsid, &other->client->fsid)) {
 758                 dout("fsid doesn't match\n");
 759                 return 0;
 760         }
 761         if (fsopt->sb_flags != other->mount_options->sb_flags) {
 762                 dout("flags differ\n");
 763                 return 0;
 764         }
 765         return 1;
 766 }
 767
 768 /*
 769  * construct our own bdi so we can control readahead, etc.
 770  */
 771 static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0);
 772
 773 static int ceph_register_bdi(struct super_block *sb,
 774                              struct ceph_fs_client *fsc)
 775 {
 776         int err;
 777
 778         /* set ra_pages based on rsize mount option? */
 779         if (fsc->mount_options->rsize >= PAGE_CACHE_SIZE)
 780                 fsc->backing_dev_info.ra_pages =
 781                         (fsc->mount_options->rsize + PAGE_CACHE_SIZE - 1)
 782                         >> PAGE_SHIFT;
 783         err = bdi_register(&fsc->backing_dev_info, NULL, "ceph-%d",
 784                            atomic_long_inc_return(&bdi_seq));
 785         if (!err)
 786                 sb->s_bdi = &fsc->backing_dev_info;
 787         return err;
 788 }
 789
 790 static struct dentry *ceph_mount(struct file_system_type *fs_type,
 791                        int flags, const char *dev_name, void *data)
 792 {
 793         struct super_block *sb;
 794         struct ceph_fs_client *fsc;
 795         struct dentry *res;
 796         int err;
 797         int (*compare_super)(struct super_block *, void *) = ceph_compare_super;
 798         const char *path = NULL;
 799         struct ceph_mount_options *fsopt = NULL;
 800         struct ceph_options *opt = NULL;
 801
 802         dout("ceph_mount\n");
 803         err = parse_mount_options(&fsopt, &opt, flags, data, dev_name, &path);
 804         if (err < 0) {
 805                 res = ERR_PTR(err);
 806                 goto out_final;
 807         }
 808
 809         /* create client (which we may/may not use) */
 810         fsc = create_fs_client(fsopt, opt);
 811         if (IS_ERR(fsc)) {
 812                 res = ERR_CAST(fsc);
 813                 kfree(fsopt);
 814                 kfree(opt);
 815                 goto out_final;
 816         }
 817
 818         err = ceph_mdsc_init(fsc);
 819         if (err < 0) {
 820                 res = ERR_PTR(err);
 821                 goto out;
 822         }
 823
 824         if (ceph_test_opt(fsc->client, NOSHARE))
 825                 compare_super = NULL;
 826         sb = sget(fs_type, compare_super, ceph_set_super, fsc);
 827         if (IS_ERR(sb)) {
 828                 res = ERR_CAST(sb);
 829                 goto out;
 830         }
 831
 832         if (ceph_sb_to_client(sb) != fsc) {
 833                 ceph_mdsc_destroy(fsc);
 834                 destroy_fs_client(fsc);
 835                 fsc = ceph_sb_to_client(sb);
 836                 dout("get_sb got existing client %p\n", fsc);
 837         } else {
 838                 dout("get_sb using new client %p\n", fsc);
 839                 err = ceph_register_bdi(sb, fsc);
 840                 if (err < 0) {
 841                         res = ERR_PTR(err);
 842                         goto out_splat;
 843                 }
 844         }
 845
 846         res = ceph_real_mount(fsc, path);
 847         if (IS_ERR(res))
 848                 goto out_splat;
 849         dout("root %p inode %p ino %llx.%llx\n", res,
 850              res->d_inode, ceph_vinop(res->d_inode));
 851         return res;
 852
 853 out_splat:
 854         ceph_mdsc_close_sessions(fsc->mdsc);
 855         deactivate_locked_super(sb);
 856         goto out_final;
 857
 858 out:
 859         ceph_mdsc_destroy(fsc);
 860         destroy_fs_client(fsc);
 861 out_final:
 862         dout("ceph_mount fail %ld\n", PTR_ERR(res));
 863         return res;
 864 }
 865
 866 static void ceph_kill_sb(struct super_block *s)
 867 {
 868         struct ceph_fs_client *fsc = ceph_sb_to_client(s);
 869         dout("kill_sb %p\n", s);
 870         ceph_mdsc_pre_umount(fsc->mdsc);
 871         kill_anon_super(s);    /* will call put_super after sb is r/o */
 872         ceph_mdsc_destroy(fsc);
 873         destroy_fs_client(fsc);
 874 }
 875
 876 static struct file_system_type ceph_fs_type = {
 877         .owner          = THIS_MODULE,
 878         .name           = "ceph",
 879         .mount          = ceph_mount,
 880         .kill_sb        = ceph_kill_sb,
 881         .fs_flags       = FS_RENAME_DOES_D_MOVE,
 882 };
 883
 884 #define _STRINGIFY(x) #x
 885 #define STRINGIFY(x) _STRINGIFY(x)
 886
 887 static int __init init_ceph(void)
 888 {
 889         int ret = init_caches();
 890         if (ret)
 891                 goto out;
 892
 893         ret = register_filesystem(&ceph_fs_type);
 894         if (ret)
 895                 goto out_icache;
 896
 897         pr_info("loaded (mds proto %d)\n", CEPH_MDSC_PROTOCOL);
 898
 899         return 0;
 900
 901 out_icache:
 902         destroy_caches();
 903 out:
 904         return ret;
 905 }
 906
 907 static void __exit exit_ceph(void)
 908 {
 909         dout("exit_ceph\n");
 910         unregister_filesystem(&ceph_fs_type);
 911         destroy_caches();
 912 }
 913
 914 module_init(init_ceph);
 915 module_exit(exit_ceph);
 916
 917 MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
 918 MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
 919 MODULE_AUTHOR("Patience Warnick <patience@newdream.net>");
 920 MODULE_DESCRIPTION("Ceph filesystem for Linux");
 921 MODULE_LICENSE("GPL");