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