xref: /openbmc/linux/fs/ceph/super.c (revision 75f25bd3)
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 		kfree(fsopt);
817 		kfree(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");
925