ceph: factor out libceph from Ceph file system
[linux-3.10.git] / 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 };
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         {-1, NULL}
154 };
155
156 static int parse_fsopt_token(char *c, void *private)
157 {
158         struct ceph_mount_options *fsopt = private;
159         substring_t argstr[MAX_OPT_ARGS];
160         int token, intval, ret;
161
162         token = match_token((char *)c, fsopt_tokens, argstr);
163         if (token < 0)
164                 return -EINVAL;
165
166         if (token < Opt_last_int) {
167                 ret = match_int(&argstr[0], &intval);
168                 if (ret < 0) {
169                         pr_err("bad mount option arg (not int) "
170                                "at '%s'\n", c);
171                         return ret;
172                 }
173                 dout("got int token %d val %d\n", token, intval);
174         } else if (token > Opt_last_int && token < Opt_last_string) {
175                 dout("got string token %d val %s\n", token,
176                      argstr[0].from);
177         } else {
178                 dout("got token %d\n", token);
179         }
180
181         switch (token) {
182         case Opt_snapdirname:
183                 kfree(fsopt->snapdir_name);
184                 fsopt->snapdir_name = kstrndup(argstr[0].from,
185                                                argstr[0].to-argstr[0].from,
186                                                GFP_KERNEL);
187                 if (!fsopt->snapdir_name)
188                         return -ENOMEM;
189                 break;
190
191                 /* misc */
192         case Opt_wsize:
193                 fsopt->wsize = intval;
194                 break;
195         case Opt_rsize:
196                 fsopt->rsize = intval;
197                 break;
198         case Opt_caps_wanted_delay_min:
199                 fsopt->caps_wanted_delay_min = intval;
200                 break;
201         case Opt_caps_wanted_delay_max:
202                 fsopt->caps_wanted_delay_max = intval;
203                 break;
204         case Opt_readdir_max_entries:
205                 fsopt->max_readdir = intval;
206                 break;
207         case Opt_readdir_max_bytes:
208                 fsopt->max_readdir_bytes = intval;
209                 break;
210         case Opt_congestion_kb:
211                 fsopt->congestion_kb = intval;
212                 break;
213         case Opt_dirstat:
214                 fsopt->flags |= CEPH_MOUNT_OPT_DIRSTAT;
215                 break;
216         case Opt_nodirstat:
217                 fsopt->flags &= ~CEPH_MOUNT_OPT_DIRSTAT;
218                 break;
219         case Opt_rbytes:
220                 fsopt->flags |= CEPH_MOUNT_OPT_RBYTES;
221                 break;
222         case Opt_norbytes:
223                 fsopt->flags &= ~CEPH_MOUNT_OPT_RBYTES;
224                 break;
225         case Opt_noasyncreaddir:
226                 fsopt->flags |= CEPH_MOUNT_OPT_NOASYNCREADDIR;
227                 break;
228         default:
229                 BUG_ON(token);
230         }
231         return 0;
232 }
233
234 static void destroy_mount_options(struct ceph_mount_options *args)
235 {
236         dout("destroy_mount_options %p\n", args);
237         kfree(args->snapdir_name);
238         kfree(args);
239 }
240
241 static int strcmp_null(const char *s1, const char *s2)
242 {
243         if (!s1 && !s2)
244                 return 0;
245         if (s1 && !s2)
246                 return -1;
247         if (!s1 && s2)
248                 return 1;
249         return strcmp(s1, s2);
250 }
251
252 static int compare_mount_options(struct ceph_mount_options *new_fsopt,
253                                  struct ceph_options *new_opt,
254                                  struct ceph_fs_client *fsc)
255 {
256         struct ceph_mount_options *fsopt1 = new_fsopt;
257         struct ceph_mount_options *fsopt2 = fsc->mount_options;
258         int ofs = offsetof(struct ceph_mount_options, snapdir_name);
259         int ret;
260
261         ret = memcmp(fsopt1, fsopt2, ofs);
262         if (ret)
263                 return ret;
264
265         ret = strcmp_null(fsopt1->snapdir_name, fsopt2->snapdir_name);
266         if (ret)
267                 return ret;
268
269         return ceph_compare_options(new_opt, fsc->client);
270 }
271
272 static int parse_mount_options(struct ceph_mount_options **pfsopt,
273                                struct ceph_options **popt,
274                                int flags, char *options,
275                                const char *dev_name,
276                                const char **path)
277 {
278         struct ceph_mount_options *fsopt;
279         const char *dev_name_end;
280         int err = -ENOMEM;
281
282         fsopt = kzalloc(sizeof(*fsopt), GFP_KERNEL);
283         if (!fsopt)
284                 return -ENOMEM;
285
286         dout("parse_mount_options %p, dev_name '%s'\n", fsopt, dev_name);
287
288         fsopt->sb_flags = flags;
289         fsopt->flags = CEPH_MOUNT_OPT_DEFAULT;
290
291         fsopt->rsize = CEPH_MOUNT_RSIZE_DEFAULT;
292         fsopt->snapdir_name = kstrdup(CEPH_SNAPDIRNAME_DEFAULT, GFP_KERNEL);
293         fsopt->cap_release_safety = CEPH_CAP_RELEASE_SAFETY_DEFAULT;
294         fsopt->max_readdir = CEPH_MAX_READDIR_DEFAULT;
295         fsopt->max_readdir_bytes = CEPH_MAX_READDIR_BYTES_DEFAULT;
296         fsopt->congestion_kb = default_congestion_kb();
297         
298         /* ip1[:port1][,ip2[:port2]...]:/subdir/in/fs */
299         err = -EINVAL;
300         if (!dev_name)
301                 goto out;
302         *path = strstr(dev_name, ":/");
303         if (*path == NULL) {
304                 pr_err("device name is missing path (no :/ in %s)\n",
305                        dev_name);
306                 goto out;
307         }
308         dev_name_end = *path;
309         dout("device name '%.*s'\n", (int)(dev_name_end - dev_name), dev_name);
310
311         /* path on server */
312         *path += 2;
313         dout("server path '%s'\n", *path);
314
315         err = ceph_parse_options(popt, options, dev_name, dev_name_end,
316                                  parse_fsopt_token, (void *)fsopt);
317         if (err)
318                 goto out;
319
320         /* success */
321         *pfsopt = fsopt;
322         return 0;
323
324 out:
325         destroy_mount_options(fsopt);
326         return err;
327 }
328
329 /**
330  * ceph_show_options - Show mount options in /proc/mounts
331  * @m: seq_file to write to
332  * @mnt: mount descriptor
333  */
334 static int ceph_show_options(struct seq_file *m, struct vfsmount *mnt)
335 {
336         struct ceph_fs_client *fsc = ceph_sb_to_client(mnt->mnt_sb);
337         struct ceph_mount_options *fsopt = fsc->mount_options;
338         struct ceph_options *opt = fsc->client->options;
339
340         if (opt->flags & CEPH_OPT_FSID)
341                 seq_printf(m, ",fsid=%pU", &opt->fsid);
342         if (opt->flags & CEPH_OPT_NOSHARE)
343                 seq_puts(m, ",noshare");
344         if (opt->flags & CEPH_OPT_NOCRC)
345                 seq_puts(m, ",nocrc");
346
347         if (opt->name)
348                 seq_printf(m, ",name=%s", opt->name);
349         if (opt->secret)
350                 seq_puts(m, ",secret=<hidden>");
351
352         if (opt->mount_timeout != CEPH_MOUNT_TIMEOUT_DEFAULT)
353                 seq_printf(m, ",mount_timeout=%d", opt->mount_timeout);
354         if (opt->osd_idle_ttl != CEPH_OSD_IDLE_TTL_DEFAULT)
355                 seq_printf(m, ",osd_idle_ttl=%d", opt->osd_idle_ttl);
356         if (opt->osd_timeout != CEPH_OSD_TIMEOUT_DEFAULT)
357                 seq_printf(m, ",osdtimeout=%d", opt->osd_timeout);
358         if (opt->osd_keepalive_timeout != CEPH_OSD_KEEPALIVE_DEFAULT)
359                 seq_printf(m, ",osdkeepalivetimeout=%d",
360                            opt->osd_keepalive_timeout);
361
362         if (fsopt->flags & CEPH_MOUNT_OPT_DIRSTAT)
363                 seq_puts(m, ",dirstat");
364         if ((fsopt->flags & CEPH_MOUNT_OPT_RBYTES) == 0)
365                 seq_puts(m, ",norbytes");
366         if (fsopt->flags & CEPH_MOUNT_OPT_NOASYNCREADDIR)
367                 seq_puts(m, ",noasyncreaddir");
368
369         if (fsopt->wsize)
370                 seq_printf(m, ",wsize=%d", fsopt->wsize);
371         if (fsopt->rsize != CEPH_MOUNT_RSIZE_DEFAULT)
372                 seq_printf(m, ",rsize=%d", fsopt->rsize);
373         if (fsopt->congestion_kb != default_congestion_kb())
374                 seq_printf(m, ",write_congestion_kb=%d", fsopt->congestion_kb);
375         if (fsopt->caps_wanted_delay_min != CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT)
376                 seq_printf(m, ",caps_wanted_delay_min=%d",
377                          fsopt->caps_wanted_delay_min);
378         if (fsopt->caps_wanted_delay_max != CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT)
379                 seq_printf(m, ",caps_wanted_delay_max=%d",
380                            fsopt->caps_wanted_delay_max);
381         if (fsopt->cap_release_safety != CEPH_CAP_RELEASE_SAFETY_DEFAULT)
382                 seq_printf(m, ",cap_release_safety=%d",
383                            fsopt->cap_release_safety);
384         if (fsopt->max_readdir != CEPH_MAX_READDIR_DEFAULT)
385                 seq_printf(m, ",readdir_max_entries=%d", fsopt->max_readdir);
386         if (fsopt->max_readdir_bytes != CEPH_MAX_READDIR_BYTES_DEFAULT)
387                 seq_printf(m, ",readdir_max_bytes=%d", fsopt->max_readdir_bytes);
388         if (strcmp(fsopt->snapdir_name, CEPH_SNAPDIRNAME_DEFAULT))
389                 seq_printf(m, ",snapdirname=%s", fsopt->snapdir_name);
390         return 0;
391 }
392
393 /*
394  * handle any mon messages the standard library doesn't understand.
395  * return error if we don't either.
396  */
397 static int extra_mon_dispatch(struct ceph_client *client, struct ceph_msg *msg)
398 {
399         struct ceph_fs_client *fsc = client->private;
400         int type = le16_to_cpu(msg->hdr.type);
401
402         switch (type) {
403         case CEPH_MSG_MDS_MAP:
404                 ceph_mdsc_handle_map(fsc->mdsc, msg);
405                 return 0;
406
407         default:
408                 return -1;
409         }
410 }
411
412 /*
413  * create a new fs client
414  */
415 struct ceph_fs_client *create_fs_client(struct ceph_mount_options *fsopt,
416                                         struct ceph_options *opt)
417 {
418         struct ceph_fs_client *fsc;
419         int err = -ENOMEM;
420
421         fsc = kzalloc(sizeof(*fsc), GFP_KERNEL);
422         if (!fsc)
423                 return ERR_PTR(-ENOMEM);
424
425         fsc->client = ceph_create_client(opt, fsc);
426         if (IS_ERR(fsc->client)) {
427                 err = PTR_ERR(fsc->client);
428                 goto fail;
429         }
430         fsc->client->extra_mon_dispatch = extra_mon_dispatch;
431         fsc->client->supported_features |= CEPH_FEATURE_FLOCK;
432         fsc->client->monc.want_mdsmap = 1;
433
434         fsc->mount_options = fsopt;
435
436         fsc->sb = NULL;
437         fsc->mount_state = CEPH_MOUNT_MOUNTING;
438
439         atomic_long_set(&fsc->writeback_count, 0);
440
441         err = bdi_init(&fsc->backing_dev_info);
442         if (err < 0)
443                 goto fail_client;
444
445         err = -ENOMEM;
446         fsc->wb_wq = create_workqueue("ceph-writeback");
447         if (fsc->wb_wq == NULL)
448                 goto fail_bdi;
449         fsc->pg_inv_wq = create_singlethread_workqueue("ceph-pg-invalid");
450         if (fsc->pg_inv_wq == NULL)
451                 goto fail_wb_wq;
452         fsc->trunc_wq = create_singlethread_workqueue("ceph-trunc");
453         if (fsc->trunc_wq == NULL)
454                 goto fail_pg_inv_wq;
455
456         /* set up mempools */
457         err = -ENOMEM;
458         fsc->wb_pagevec_pool = mempool_create_kmalloc_pool(10,
459                               fsc->mount_options->wsize >> PAGE_CACHE_SHIFT);
460         if (!fsc->wb_pagevec_pool)
461                 goto fail_trunc_wq;
462
463         /* caps */
464         fsc->min_caps = fsopt->max_readdir;
465
466         return fsc;
467
468 fail_trunc_wq:
469         destroy_workqueue(fsc->trunc_wq);
470 fail_pg_inv_wq:
471         destroy_workqueue(fsc->pg_inv_wq);
472 fail_wb_wq:
473         destroy_workqueue(fsc->wb_wq);
474 fail_bdi:
475         bdi_destroy(&fsc->backing_dev_info);
476 fail_client:
477         ceph_destroy_client(fsc->client);
478 fail:
479         kfree(fsc);
480         return ERR_PTR(err);
481 }
482
483 void destroy_fs_client(struct ceph_fs_client *fsc)
484 {
485         dout("destroy_fs_client %p\n", fsc);
486
487         destroy_workqueue(fsc->wb_wq);
488         destroy_workqueue(fsc->pg_inv_wq);
489         destroy_workqueue(fsc->trunc_wq);
490
491         bdi_destroy(&fsc->backing_dev_info);
492
493         mempool_destroy(fsc->wb_pagevec_pool);
494
495         destroy_mount_options(fsc->mount_options);
496
497         ceph_fs_debugfs_cleanup(fsc);
498
499         ceph_destroy_client(fsc->client);
500
501         kfree(fsc);
502         dout("destroy_fs_client %p done\n", fsc);
503 }
504
505 /*
506  * caches
507  */
508 struct kmem_cache *ceph_inode_cachep;
509 struct kmem_cache *ceph_cap_cachep;
510 struct kmem_cache *ceph_dentry_cachep;
511 struct kmem_cache *ceph_file_cachep;
512
513 static void ceph_inode_init_once(void *foo)
514 {
515         struct ceph_inode_info *ci = foo;
516         inode_init_once(&ci->vfs_inode);
517 }
518
519 static int __init init_caches(void)
520 {
521         ceph_inode_cachep = kmem_cache_create("ceph_inode_info",
522                                       sizeof(struct ceph_inode_info),
523                                       __alignof__(struct ceph_inode_info),
524                                       (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD),
525                                       ceph_inode_init_once);
526         if (ceph_inode_cachep == NULL)
527                 return -ENOMEM;
528
529         ceph_cap_cachep = KMEM_CACHE(ceph_cap,
530                                      SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
531         if (ceph_cap_cachep == NULL)
532                 goto bad_cap;
533
534         ceph_dentry_cachep = KMEM_CACHE(ceph_dentry_info,
535                                         SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
536         if (ceph_dentry_cachep == NULL)
537                 goto bad_dentry;
538
539         ceph_file_cachep = KMEM_CACHE(ceph_file_info,
540                                       SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
541         if (ceph_file_cachep == NULL)
542                 goto bad_file;
543
544         return 0;
545
546 bad_file:
547         kmem_cache_destroy(ceph_dentry_cachep);
548 bad_dentry:
549         kmem_cache_destroy(ceph_cap_cachep);
550 bad_cap:
551         kmem_cache_destroy(ceph_inode_cachep);
552         return -ENOMEM;
553 }
554
555 static void destroy_caches(void)
556 {
557         kmem_cache_destroy(ceph_inode_cachep);
558         kmem_cache_destroy(ceph_cap_cachep);
559         kmem_cache_destroy(ceph_dentry_cachep);
560         kmem_cache_destroy(ceph_file_cachep);
561 }
562
563
564 /*
565  * ceph_umount_begin - initiate forced umount.  Tear down down the
566  * mount, skipping steps that may hang while waiting for server(s).
567  */
568 static void ceph_umount_begin(struct super_block *sb)
569 {
570         struct ceph_fs_client *fsc = ceph_sb_to_client(sb);
571
572         dout("ceph_umount_begin - starting forced umount\n");
573         if (!fsc)
574                 return;
575         fsc->mount_state = CEPH_MOUNT_SHUTDOWN;
576         return;
577 }
578
579 static const struct super_operations ceph_super_ops = {
580         .alloc_inode    = ceph_alloc_inode,
581         .destroy_inode  = ceph_destroy_inode,
582         .write_inode    = ceph_write_inode,
583         .sync_fs        = ceph_sync_fs,
584         .put_super      = ceph_put_super,
585         .show_options   = ceph_show_options,
586         .statfs         = ceph_statfs,
587         .umount_begin   = ceph_umount_begin,
588 };
589
590 /*
591  * Bootstrap mount by opening the root directory.  Note the mount
592  * @started time from caller, and time out if this takes too long.
593  */
594 static struct dentry *open_root_dentry(struct ceph_fs_client *fsc,
595                                        const char *path,
596                                        unsigned long started)
597 {
598         struct ceph_mds_client *mdsc = fsc->mdsc;
599         struct ceph_mds_request *req = NULL;
600         int err;
601         struct dentry *root;
602
603         /* open dir */
604         dout("open_root_inode opening '%s'\n", path);
605         req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_GETATTR, USE_ANY_MDS);
606         if (IS_ERR(req))
607                 return ERR_CAST(req);
608         req->r_path1 = kstrdup(path, GFP_NOFS);
609         req->r_ino1.ino = CEPH_INO_ROOT;
610         req->r_ino1.snap = CEPH_NOSNAP;
611         req->r_started = started;
612         req->r_timeout = fsc->client->options->mount_timeout * HZ;
613         req->r_args.getattr.mask = cpu_to_le32(CEPH_STAT_CAP_INODE);
614         req->r_num_caps = 2;
615         err = ceph_mdsc_do_request(mdsc, NULL, req);
616         if (err == 0) {
617                 dout("open_root_inode success\n");
618                 if (ceph_ino(req->r_target_inode) == CEPH_INO_ROOT &&
619                     fsc->sb->s_root == NULL)
620                         root = d_alloc_root(req->r_target_inode);
621                 else
622                         root = d_obtain_alias(req->r_target_inode);
623                 req->r_target_inode = NULL;
624                 dout("open_root_inode success, root dentry is %p\n", root);
625         } else {
626                 root = ERR_PTR(err);
627         }
628         ceph_mdsc_put_request(req);
629         return root;
630 }
631
632
633
634
635 /*
636  * mount: join the ceph cluster, and open root directory.
637  */
638 static int ceph_mount(struct ceph_fs_client *fsc, struct vfsmount *mnt,
639                       const char *path)
640 {
641         int err;
642         unsigned long started = jiffies;  /* note the start time */
643         struct dentry *root;
644         int first = 0;   /* first vfsmount for this super_block */
645
646         dout("mount start\n");
647         mutex_lock(&fsc->client->mount_mutex);
648
649         err = __ceph_open_session(fsc->client, started);
650         if (err < 0)
651                 goto out;
652
653         dout("mount opening root\n");
654         root = open_root_dentry(fsc, "", started);
655         if (IS_ERR(root)) {
656                 err = PTR_ERR(root);
657                 goto out;
658         }
659         if (fsc->sb->s_root) {
660                 dput(root);
661         } else {
662                 fsc->sb->s_root = root;
663                 first = 1;
664
665                 err = ceph_fs_debugfs_init(fsc);
666                 if (err < 0)
667                         goto fail;
668         }
669
670         if (path[0] == 0) {
671                 dget(root);
672         } else {
673                 dout("mount opening base mountpoint\n");
674                 root = open_root_dentry(fsc, path, started);
675                 if (IS_ERR(root)) {
676                         err = PTR_ERR(root);
677                         goto fail;
678                 }
679         }
680
681         mnt->mnt_root = root;
682         mnt->mnt_sb = fsc->sb;
683
684         fsc->mount_state = CEPH_MOUNT_MOUNTED;
685         dout("mount success\n");
686         err = 0;
687
688 out:
689         mutex_unlock(&fsc->client->mount_mutex);
690         return err;
691
692 fail:
693         if (first) {
694                 dput(fsc->sb->s_root);
695                 fsc->sb->s_root = NULL;
696         }
697         goto out;
698 }
699
700 static int ceph_set_super(struct super_block *s, void *data)
701 {
702         struct ceph_fs_client *fsc = data;
703         int ret;
704
705         dout("set_super %p data %p\n", s, data);
706
707         s->s_flags = fsc->mount_options->sb_flags;
708         s->s_maxbytes = 1ULL << 40;  /* temp value until we get mdsmap */
709
710         s->s_fs_info = fsc;
711         fsc->sb = s;
712
713         s->s_op = &ceph_super_ops;
714         s->s_export_op = &ceph_export_ops;
715
716         s->s_time_gran = 1000;  /* 1000 ns == 1 us */
717
718         ret = set_anon_super(s, NULL);  /* what is that second arg for? */
719         if (ret != 0)
720                 goto fail;
721
722         return ret;
723
724 fail:
725         s->s_fs_info = NULL;
726         fsc->sb = NULL;
727         return ret;
728 }
729
730 /*
731  * share superblock if same fs AND options
732  */
733 static int ceph_compare_super(struct super_block *sb, void *data)
734 {
735         struct ceph_fs_client *new = data;
736         struct ceph_mount_options *fsopt = new->mount_options;
737         struct ceph_options *opt = new->client->options;
738         struct ceph_fs_client *other = ceph_sb_to_client(sb);
739
740         dout("ceph_compare_super %p\n", sb);
741
742         if (compare_mount_options(fsopt, opt, other)) {
743                 dout("monitor(s)/mount options don't match\n");
744                 return 0;
745         }
746         if ((opt->flags & CEPH_OPT_FSID) &&
747             ceph_fsid_compare(&opt->fsid, &other->client->fsid)) {
748                 dout("fsid doesn't match\n");
749                 return 0;
750         }
751         if (fsopt->sb_flags != other->mount_options->sb_flags) {
752                 dout("flags differ\n");
753                 return 0;
754         }
755         return 1;
756 }
757
758 /*
759  * construct our own bdi so we can control readahead, etc.
760  */
761 static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0);
762
763 static int ceph_register_bdi(struct super_block *sb,
764                              struct ceph_fs_client *fsc)
765 {
766         int err;
767
768         /* set ra_pages based on rsize mount option? */
769         if (fsc->mount_options->rsize >= PAGE_CACHE_SIZE)
770                 fsc->backing_dev_info.ra_pages =
771                         (fsc->mount_options->rsize + PAGE_CACHE_SIZE - 1)
772                         >> PAGE_SHIFT;
773         err = bdi_register(&fsc->backing_dev_info, NULL, "ceph-%d",
774                            atomic_long_inc_return(&bdi_seq));
775         if (!err)
776                 sb->s_bdi = &fsc->backing_dev_info;
777         return err;
778 }
779
780 static int ceph_get_sb(struct file_system_type *fs_type,
781                        int flags, const char *dev_name, void *data,
782                        struct vfsmount *mnt)
783 {
784         struct super_block *sb;
785         struct ceph_fs_client *fsc;
786         int err;
787         int (*compare_super)(struct super_block *, void *) = ceph_compare_super;
788         const char *path = NULL;
789         struct ceph_mount_options *fsopt = NULL;
790         struct ceph_options *opt = NULL;
791
792         dout("ceph_get_sb\n");
793         err = parse_mount_options(&fsopt, &opt, flags, data, dev_name, &path);
794         if (err < 0)
795                 goto out_final;
796
797         /* create client (which we may/may not use) */
798         fsc = create_fs_client(fsopt, opt);
799         if (IS_ERR(fsc)) {
800                 err = PTR_ERR(fsc);
801                 kfree(fsopt);
802                 kfree(opt);
803                 goto out_final;
804         }
805
806         err = ceph_mdsc_init(fsc);
807         if (err < 0)
808                 goto out;
809
810         if (ceph_test_opt(fsc->client, NOSHARE))
811                 compare_super = NULL;
812         sb = sget(fs_type, compare_super, ceph_set_super, fsc);
813         if (IS_ERR(sb)) {
814                 err = PTR_ERR(sb);
815                 goto out;
816         }
817
818         if (ceph_sb_to_client(sb) != fsc) {
819                 ceph_mdsc_destroy(fsc);
820                 destroy_fs_client(fsc);
821                 fsc = ceph_sb_to_client(sb);
822                 dout("get_sb got existing client %p\n", fsc);
823         } else {
824                 dout("get_sb using new client %p\n", fsc);
825                 err = ceph_register_bdi(sb, fsc);
826                 if (err < 0)
827                         goto out_splat;
828         }
829
830         err = ceph_mount(fsc, mnt, path);
831         if (err < 0)
832                 goto out_splat;
833         dout("root %p inode %p ino %llx.%llx\n", mnt->mnt_root,
834              mnt->mnt_root->d_inode, ceph_vinop(mnt->mnt_root->d_inode));
835         return 0;
836
837 out_splat:
838         ceph_mdsc_close_sessions(fsc->mdsc);
839         deactivate_locked_super(sb);
840         goto out_final;
841
842 out:
843         ceph_mdsc_destroy(fsc);
844         destroy_fs_client(fsc);
845 out_final:
846         dout("ceph_get_sb fail %d\n", err);
847         return err;
848 }
849
850 static void ceph_kill_sb(struct super_block *s)
851 {
852         struct ceph_fs_client *fsc = ceph_sb_to_client(s);
853         dout("kill_sb %p\n", s);
854         ceph_mdsc_pre_umount(fsc->mdsc);
855         kill_anon_super(s);    /* will call put_super after sb is r/o */
856         ceph_mdsc_destroy(fsc);
857         destroy_fs_client(fsc);
858 }
859
860 static struct file_system_type ceph_fs_type = {
861         .owner          = THIS_MODULE,
862         .name           = "ceph",
863         .get_sb         = ceph_get_sb,
864         .kill_sb        = ceph_kill_sb,
865         .fs_flags       = FS_RENAME_DOES_D_MOVE,
866 };
867
868 #define _STRINGIFY(x) #x
869 #define STRINGIFY(x) _STRINGIFY(x)
870
871 static int __init init_ceph(void)
872 {
873         int ret = init_caches();
874         if (ret)
875                 goto out;
876
877         ret = register_filesystem(&ceph_fs_type);
878         if (ret)
879                 goto out_icache;
880
881         pr_info("loaded (mds proto %d)\n", CEPH_MDSC_PROTOCOL);
882
883         return 0;
884
885 out_icache:
886         destroy_caches();
887 out:
888         return ret;
889 }
890
891 static void __exit exit_ceph(void)
892 {
893         dout("exit_ceph\n");
894         unregister_filesystem(&ceph_fs_type);
895         destroy_caches();
896 }
897
898 module_init(init_ceph);
899 module_exit(exit_ceph);
900
901 MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
902 MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
903 MODULE_AUTHOR("Patience Warnick <patience@newdream.net>");
904 MODULE_DESCRIPTION("Ceph filesystem for Linux");
905 MODULE_LICENSE("GPL");