xref: /linux/fs/ceph/super.c (revision 25aee3debe0464f6c680173041fa3de30ec9ff54)
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/ceph_features.h>
22 #include <linux/ceph/decode.h>
23 #include <linux/ceph/mon_client.h>
24 #include <linux/ceph/auth.h>
25 #include <linux/ceph/debugfs.h>
26 
27 /*
28  * Ceph superblock operations
29  *
30  * Handle the basics of mounting, unmounting.
31  */
32 
33 /*
34  * super ops
35  */
36 static void ceph_put_super(struct super_block *s)
37 {
38 	struct ceph_fs_client *fsc = ceph_sb_to_client(s);
39 
40 	dout("put_super\n");
41 	ceph_mdsc_close_sessions(fsc->mdsc);
42 
43 	/*
44 	 * ensure we release the bdi before put_anon_super releases
45 	 * the device name.
46 	 */
47 	if (s->s_bdi == &fsc->backing_dev_info) {
48 		bdi_unregister(&fsc->backing_dev_info);
49 		s->s_bdi = NULL;
50 	}
51 
52 	return;
53 }
54 
55 static int ceph_statfs(struct dentry *dentry, struct kstatfs *buf)
56 {
57 	struct ceph_fs_client *fsc = ceph_inode_to_client(dentry->d_inode);
58 	struct ceph_monmap *monmap = fsc->client->monc.monmap;
59 	struct ceph_statfs st;
60 	u64 fsid;
61 	int err;
62 
63 	dout("statfs\n");
64 	err = ceph_monc_do_statfs(&fsc->client->monc, &st);
65 	if (err < 0)
66 		return err;
67 
68 	/* fill in kstatfs */
69 	buf->f_type = CEPH_SUPER_MAGIC;  /* ?? */
70 
71 	/*
72 	 * express utilization in terms of large blocks to avoid
73 	 * overflow on 32-bit machines.
74 	 */
75 	buf->f_bsize = 1 << CEPH_BLOCK_SHIFT;
76 	buf->f_blocks = le64_to_cpu(st.kb) >> (CEPH_BLOCK_SHIFT-10);
77 	buf->f_bfree = le64_to_cpu(st.kb_avail) >> (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_rasize,
119 	Opt_caps_wanted_delay_min,
120 	Opt_caps_wanted_delay_max,
121 	Opt_cap_release_safety,
122 	Opt_readdir_max_entries,
123 	Opt_readdir_max_bytes,
124 	Opt_congestion_kb,
125 	Opt_last_int,
126 	/* int args above */
127 	Opt_snapdirname,
128 	Opt_last_string,
129 	/* string args above */
130 	Opt_dirstat,
131 	Opt_nodirstat,
132 	Opt_rbytes,
133 	Opt_norbytes,
134 	Opt_asyncreaddir,
135 	Opt_noasyncreaddir,
136 	Opt_dcache,
137 	Opt_nodcache,
138 	Opt_ino32,
139 	Opt_noino32,
140 };
141 
142 static match_table_t fsopt_tokens = {
143 	{Opt_wsize, "wsize=%d"},
144 	{Opt_rsize, "rsize=%d"},
145 	{Opt_rasize, "rasize=%d"},
146 	{Opt_caps_wanted_delay_min, "caps_wanted_delay_min=%d"},
147 	{Opt_caps_wanted_delay_max, "caps_wanted_delay_max=%d"},
148 	{Opt_cap_release_safety, "cap_release_safety=%d"},
149 	{Opt_readdir_max_entries, "readdir_max_entries=%d"},
150 	{Opt_readdir_max_bytes, "readdir_max_bytes=%d"},
151 	{Opt_congestion_kb, "write_congestion_kb=%d"},
152 	/* int args above */
153 	{Opt_snapdirname, "snapdirname=%s"},
154 	/* string args above */
155 	{Opt_dirstat, "dirstat"},
156 	{Opt_nodirstat, "nodirstat"},
157 	{Opt_rbytes, "rbytes"},
158 	{Opt_norbytes, "norbytes"},
159 	{Opt_asyncreaddir, "asyncreaddir"},
160 	{Opt_noasyncreaddir, "noasyncreaddir"},
161 	{Opt_dcache, "dcache"},
162 	{Opt_nodcache, "nodcache"},
163 	{Opt_ino32, "ino32"},
164 	{Opt_noino32, "noino32"},
165 	{-1, NULL}
166 };
167 
168 static int parse_fsopt_token(char *c, void *private)
169 {
170 	struct ceph_mount_options *fsopt = private;
171 	substring_t argstr[MAX_OPT_ARGS];
172 	int token, intval, ret;
173 
174 	token = match_token((char *)c, fsopt_tokens, argstr);
175 	if (token < 0)
176 		return -EINVAL;
177 
178 	if (token < Opt_last_int) {
179 		ret = match_int(&argstr[0], &intval);
180 		if (ret < 0) {
181 			pr_err("bad mount option arg (not int) "
182 			       "at '%s'\n", c);
183 			return ret;
184 		}
185 		dout("got int token %d val %d\n", token, intval);
186 	} else if (token > Opt_last_int && token < Opt_last_string) {
187 		dout("got string token %d val %s\n", token,
188 		     argstr[0].from);
189 	} else {
190 		dout("got token %d\n", token);
191 	}
192 
193 	switch (token) {
194 	case Opt_snapdirname:
195 		kfree(fsopt->snapdir_name);
196 		fsopt->snapdir_name = kstrndup(argstr[0].from,
197 					       argstr[0].to-argstr[0].from,
198 					       GFP_KERNEL);
199 		if (!fsopt->snapdir_name)
200 			return -ENOMEM;
201 		break;
202 
203 		/* misc */
204 	case Opt_wsize:
205 		fsopt->wsize = intval;
206 		break;
207 	case Opt_rsize:
208 		fsopt->rsize = intval;
209 		break;
210 	case Opt_rasize:
211 		fsopt->rasize = intval;
212 		break;
213 	case Opt_caps_wanted_delay_min:
214 		fsopt->caps_wanted_delay_min = intval;
215 		break;
216 	case Opt_caps_wanted_delay_max:
217 		fsopt->caps_wanted_delay_max = intval;
218 		break;
219 	case Opt_readdir_max_entries:
220 		fsopt->max_readdir = intval;
221 		break;
222 	case Opt_readdir_max_bytes:
223 		fsopt->max_readdir_bytes = intval;
224 		break;
225 	case Opt_congestion_kb:
226 		fsopt->congestion_kb = intval;
227 		break;
228 	case Opt_dirstat:
229 		fsopt->flags |= CEPH_MOUNT_OPT_DIRSTAT;
230 		break;
231 	case Opt_nodirstat:
232 		fsopt->flags &= ~CEPH_MOUNT_OPT_DIRSTAT;
233 		break;
234 	case Opt_rbytes:
235 		fsopt->flags |= CEPH_MOUNT_OPT_RBYTES;
236 		break;
237 	case Opt_norbytes:
238 		fsopt->flags &= ~CEPH_MOUNT_OPT_RBYTES;
239 		break;
240 	case Opt_asyncreaddir:
241 		fsopt->flags &= ~CEPH_MOUNT_OPT_NOASYNCREADDIR;
242 		break;
243 	case Opt_noasyncreaddir:
244 		fsopt->flags |= CEPH_MOUNT_OPT_NOASYNCREADDIR;
245 		break;
246 	case Opt_dcache:
247 		fsopt->flags |= CEPH_MOUNT_OPT_DCACHE;
248 		break;
249 	case Opt_nodcache:
250 		fsopt->flags &= ~CEPH_MOUNT_OPT_DCACHE;
251 		break;
252 	case Opt_ino32:
253 		fsopt->flags |= CEPH_MOUNT_OPT_INO32;
254 		break;
255 	case Opt_noino32:
256 		fsopt->flags &= ~CEPH_MOUNT_OPT_INO32;
257 		break;
258 	default:
259 		BUG_ON(token);
260 	}
261 	return 0;
262 }
263 
264 static void destroy_mount_options(struct ceph_mount_options *args)
265 {
266 	dout("destroy_mount_options %p\n", args);
267 	kfree(args->snapdir_name);
268 	kfree(args);
269 }
270 
271 static int strcmp_null(const char *s1, const char *s2)
272 {
273 	if (!s1 && !s2)
274 		return 0;
275 	if (s1 && !s2)
276 		return -1;
277 	if (!s1 && s2)
278 		return 1;
279 	return strcmp(s1, s2);
280 }
281 
282 static int compare_mount_options(struct ceph_mount_options *new_fsopt,
283 				 struct ceph_options *new_opt,
284 				 struct ceph_fs_client *fsc)
285 {
286 	struct ceph_mount_options *fsopt1 = new_fsopt;
287 	struct ceph_mount_options *fsopt2 = fsc->mount_options;
288 	int ofs = offsetof(struct ceph_mount_options, snapdir_name);
289 	int ret;
290 
291 	ret = memcmp(fsopt1, fsopt2, ofs);
292 	if (ret)
293 		return ret;
294 
295 	ret = strcmp_null(fsopt1->snapdir_name, fsopt2->snapdir_name);
296 	if (ret)
297 		return ret;
298 
299 	return ceph_compare_options(new_opt, fsc->client);
300 }
301 
302 static int parse_mount_options(struct ceph_mount_options **pfsopt,
303 			       struct ceph_options **popt,
304 			       int flags, char *options,
305 			       const char *dev_name,
306 			       const char **path)
307 {
308 	struct ceph_mount_options *fsopt;
309 	const char *dev_name_end;
310 	int err = -ENOMEM;
311 
312 	fsopt = kzalloc(sizeof(*fsopt), GFP_KERNEL);
313 	if (!fsopt)
314 		return -ENOMEM;
315 
316 	dout("parse_mount_options %p, dev_name '%s'\n", fsopt, dev_name);
317 
318 	fsopt->sb_flags = flags;
319 	fsopt->flags = CEPH_MOUNT_OPT_DEFAULT;
320 
321 	fsopt->rsize = CEPH_RSIZE_DEFAULT;
322 	fsopt->rasize = CEPH_RASIZE_DEFAULT;
323 	fsopt->snapdir_name = kstrdup(CEPH_SNAPDIRNAME_DEFAULT, GFP_KERNEL);
324 	fsopt->caps_wanted_delay_min = CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT;
325 	fsopt->caps_wanted_delay_max = CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT;
326 	fsopt->cap_release_safety = CEPH_CAP_RELEASE_SAFETY_DEFAULT;
327 	fsopt->max_readdir = CEPH_MAX_READDIR_DEFAULT;
328 	fsopt->max_readdir_bytes = CEPH_MAX_READDIR_BYTES_DEFAULT;
329 	fsopt->congestion_kb = default_congestion_kb();
330 
331 	/* ip1[:port1][,ip2[:port2]...]:/subdir/in/fs */
332 	err = -EINVAL;
333 	if (!dev_name)
334 		goto out;
335 	*path = strstr(dev_name, ":/");
336 	if (*path == NULL) {
337 		pr_err("device name is missing path (no :/ in %s)\n",
338 				dev_name);
339 		goto out;
340 	}
341 	dev_name_end = *path;
342 	dout("device name '%.*s'\n", (int)(dev_name_end - dev_name), dev_name);
343 
344 	/* path on server */
345 	*path += 2;
346 	dout("server path '%s'\n", *path);
347 
348 	*popt = ceph_parse_options(options, dev_name, dev_name_end,
349 				 parse_fsopt_token, (void *)fsopt);
350 	if (IS_ERR(*popt)) {
351 		err = PTR_ERR(*popt);
352 		goto out;
353 	}
354 
355 	/* success */
356 	*pfsopt = fsopt;
357 	return 0;
358 
359 out:
360 	destroy_mount_options(fsopt);
361 	return err;
362 }
363 
364 /**
365  * ceph_show_options - Show mount options in /proc/mounts
366  * @m: seq_file to write to
367  * @root: root of that (sub)tree
368  */
369 static int ceph_show_options(struct seq_file *m, struct dentry *root)
370 {
371 	struct ceph_fs_client *fsc = ceph_sb_to_client(root->d_sb);
372 	struct ceph_mount_options *fsopt = fsc->mount_options;
373 	struct ceph_options *opt = fsc->client->options;
374 
375 	if (opt->flags & CEPH_OPT_FSID)
376 		seq_printf(m, ",fsid=%pU", &opt->fsid);
377 	if (opt->flags & CEPH_OPT_NOSHARE)
378 		seq_puts(m, ",noshare");
379 	if (opt->flags & CEPH_OPT_NOCRC)
380 		seq_puts(m, ",nocrc");
381 
382 	if (opt->name)
383 		seq_printf(m, ",name=%s", opt->name);
384 	if (opt->key)
385 		seq_puts(m, ",secret=<hidden>");
386 
387 	if (opt->mount_timeout != CEPH_MOUNT_TIMEOUT_DEFAULT)
388 		seq_printf(m, ",mount_timeout=%d", opt->mount_timeout);
389 	if (opt->osd_idle_ttl != CEPH_OSD_IDLE_TTL_DEFAULT)
390 		seq_printf(m, ",osd_idle_ttl=%d", opt->osd_idle_ttl);
391 	if (opt->osd_timeout != CEPH_OSD_TIMEOUT_DEFAULT)
392 		seq_printf(m, ",osdtimeout=%d", opt->osd_timeout);
393 	if (opt->osd_keepalive_timeout != CEPH_OSD_KEEPALIVE_DEFAULT)
394 		seq_printf(m, ",osdkeepalivetimeout=%d",
395 			   opt->osd_keepalive_timeout);
396 
397 	if (fsopt->flags & CEPH_MOUNT_OPT_DIRSTAT)
398 		seq_puts(m, ",dirstat");
399 	if ((fsopt->flags & CEPH_MOUNT_OPT_RBYTES) == 0)
400 		seq_puts(m, ",norbytes");
401 	if (fsopt->flags & CEPH_MOUNT_OPT_NOASYNCREADDIR)
402 		seq_puts(m, ",noasyncreaddir");
403 	if (fsopt->flags & CEPH_MOUNT_OPT_DCACHE)
404 		seq_puts(m, ",dcache");
405 	else
406 		seq_puts(m, ",nodcache");
407 
408 	if (fsopt->wsize)
409 		seq_printf(m, ",wsize=%d", fsopt->wsize);
410 	if (fsopt->rsize != CEPH_RSIZE_DEFAULT)
411 		seq_printf(m, ",rsize=%d", fsopt->rsize);
412 	if (fsopt->rasize != CEPH_RASIZE_DEFAULT)
413 		seq_printf(m, ",rasize=%d", fsopt->rasize);
414 	if (fsopt->congestion_kb != default_congestion_kb())
415 		seq_printf(m, ",write_congestion_kb=%d", fsopt->congestion_kb);
416 	if (fsopt->caps_wanted_delay_min != CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT)
417 		seq_printf(m, ",caps_wanted_delay_min=%d",
418 			 fsopt->caps_wanted_delay_min);
419 	if (fsopt->caps_wanted_delay_max != CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT)
420 		seq_printf(m, ",caps_wanted_delay_max=%d",
421 			   fsopt->caps_wanted_delay_max);
422 	if (fsopt->cap_release_safety != CEPH_CAP_RELEASE_SAFETY_DEFAULT)
423 		seq_printf(m, ",cap_release_safety=%d",
424 			   fsopt->cap_release_safety);
425 	if (fsopt->max_readdir != CEPH_MAX_READDIR_DEFAULT)
426 		seq_printf(m, ",readdir_max_entries=%d", fsopt->max_readdir);
427 	if (fsopt->max_readdir_bytes != CEPH_MAX_READDIR_BYTES_DEFAULT)
428 		seq_printf(m, ",readdir_max_bytes=%d", fsopt->max_readdir_bytes);
429 	if (strcmp(fsopt->snapdir_name, CEPH_SNAPDIRNAME_DEFAULT))
430 		seq_printf(m, ",snapdirname=%s", fsopt->snapdir_name);
431 	return 0;
432 }
433 
434 /*
435  * handle any mon messages the standard library doesn't understand.
436  * return error if we don't either.
437  */
438 static int extra_mon_dispatch(struct ceph_client *client, struct ceph_msg *msg)
439 {
440 	struct ceph_fs_client *fsc = client->private;
441 	int type = le16_to_cpu(msg->hdr.type);
442 
443 	switch (type) {
444 	case CEPH_MSG_MDS_MAP:
445 		ceph_mdsc_handle_map(fsc->mdsc, msg);
446 		return 0;
447 
448 	default:
449 		return -1;
450 	}
451 }
452 
453 /*
454  * create a new fs client
455  */
456 static struct ceph_fs_client *create_fs_client(struct ceph_mount_options *fsopt,
457 					struct ceph_options *opt)
458 {
459 	struct ceph_fs_client *fsc;
460 	const unsigned supported_features =
461 		CEPH_FEATURE_FLOCK |
462 		CEPH_FEATURE_DIRLAYOUTHASH;
463 	const unsigned required_features = 0;
464 	int err = -ENOMEM;
465 
466 	fsc = kzalloc(sizeof(*fsc), GFP_KERNEL);
467 	if (!fsc)
468 		return ERR_PTR(-ENOMEM);
469 
470 	fsc->client = ceph_create_client(opt, fsc, supported_features,
471 					 required_features);
472 	if (IS_ERR(fsc->client)) {
473 		err = PTR_ERR(fsc->client);
474 		goto fail;
475 	}
476 	fsc->client->extra_mon_dispatch = extra_mon_dispatch;
477 	fsc->client->monc.want_mdsmap = 1;
478 
479 	fsc->mount_options = fsopt;
480 
481 	fsc->sb = NULL;
482 	fsc->mount_state = CEPH_MOUNT_MOUNTING;
483 
484 	atomic_long_set(&fsc->writeback_count, 0);
485 
486 	err = bdi_init(&fsc->backing_dev_info);
487 	if (err < 0)
488 		goto fail_client;
489 
490 	err = -ENOMEM;
491 	/*
492 	 * The number of concurrent works can be high but they don't need
493 	 * to be processed in parallel, limit concurrency.
494 	 */
495 	fsc->wb_wq = alloc_workqueue("ceph-writeback", 0, 1);
496 	if (fsc->wb_wq == NULL)
497 		goto fail_bdi;
498 	fsc->pg_inv_wq = alloc_workqueue("ceph-pg-invalid", 0, 1);
499 	if (fsc->pg_inv_wq == NULL)
500 		goto fail_wb_wq;
501 	fsc->trunc_wq = alloc_workqueue("ceph-trunc", 0, 1);
502 	if (fsc->trunc_wq == NULL)
503 		goto fail_pg_inv_wq;
504 
505 	/* set up mempools */
506 	err = -ENOMEM;
507 	fsc->wb_pagevec_pool = mempool_create_kmalloc_pool(10,
508 			      fsc->mount_options->wsize >> PAGE_CACHE_SHIFT);
509 	if (!fsc->wb_pagevec_pool)
510 		goto fail_trunc_wq;
511 
512 	/* caps */
513 	fsc->min_caps = fsopt->max_readdir;
514 
515 	return fsc;
516 
517 fail_trunc_wq:
518 	destroy_workqueue(fsc->trunc_wq);
519 fail_pg_inv_wq:
520 	destroy_workqueue(fsc->pg_inv_wq);
521 fail_wb_wq:
522 	destroy_workqueue(fsc->wb_wq);
523 fail_bdi:
524 	bdi_destroy(&fsc->backing_dev_info);
525 fail_client:
526 	ceph_destroy_client(fsc->client);
527 fail:
528 	kfree(fsc);
529 	return ERR_PTR(err);
530 }
531 
532 static void destroy_fs_client(struct ceph_fs_client *fsc)
533 {
534 	dout("destroy_fs_client %p\n", fsc);
535 
536 	destroy_workqueue(fsc->wb_wq);
537 	destroy_workqueue(fsc->pg_inv_wq);
538 	destroy_workqueue(fsc->trunc_wq);
539 
540 	bdi_destroy(&fsc->backing_dev_info);
541 
542 	mempool_destroy(fsc->wb_pagevec_pool);
543 
544 	destroy_mount_options(fsc->mount_options);
545 
546 	ceph_fs_debugfs_cleanup(fsc);
547 
548 	ceph_destroy_client(fsc->client);
549 
550 	kfree(fsc);
551 	dout("destroy_fs_client %p done\n", fsc);
552 }
553 
554 /*
555  * caches
556  */
557 struct kmem_cache *ceph_inode_cachep;
558 struct kmem_cache *ceph_cap_cachep;
559 struct kmem_cache *ceph_dentry_cachep;
560 struct kmem_cache *ceph_file_cachep;
561 
562 static void ceph_inode_init_once(void *foo)
563 {
564 	struct ceph_inode_info *ci = foo;
565 	inode_init_once(&ci->vfs_inode);
566 }
567 
568 static int __init init_caches(void)
569 {
570 	ceph_inode_cachep = kmem_cache_create("ceph_inode_info",
571 				      sizeof(struct ceph_inode_info),
572 				      __alignof__(struct ceph_inode_info),
573 				      (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD),
574 				      ceph_inode_init_once);
575 	if (ceph_inode_cachep == NULL)
576 		return -ENOMEM;
577 
578 	ceph_cap_cachep = KMEM_CACHE(ceph_cap,
579 				     SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
580 	if (ceph_cap_cachep == NULL)
581 		goto bad_cap;
582 
583 	ceph_dentry_cachep = KMEM_CACHE(ceph_dentry_info,
584 					SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
585 	if (ceph_dentry_cachep == NULL)
586 		goto bad_dentry;
587 
588 	ceph_file_cachep = KMEM_CACHE(ceph_file_info,
589 				      SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
590 	if (ceph_file_cachep == NULL)
591 		goto bad_file;
592 
593 	return 0;
594 
595 bad_file:
596 	kmem_cache_destroy(ceph_dentry_cachep);
597 bad_dentry:
598 	kmem_cache_destroy(ceph_cap_cachep);
599 bad_cap:
600 	kmem_cache_destroy(ceph_inode_cachep);
601 	return -ENOMEM;
602 }
603 
604 static void destroy_caches(void)
605 {
606 	kmem_cache_destroy(ceph_inode_cachep);
607 	kmem_cache_destroy(ceph_cap_cachep);
608 	kmem_cache_destroy(ceph_dentry_cachep);
609 	kmem_cache_destroy(ceph_file_cachep);
610 }
611 
612 
613 /*
614  * ceph_umount_begin - initiate forced umount.  Tear down down the
615  * mount, skipping steps that may hang while waiting for server(s).
616  */
617 static void ceph_umount_begin(struct super_block *sb)
618 {
619 	struct ceph_fs_client *fsc = ceph_sb_to_client(sb);
620 
621 	dout("ceph_umount_begin - starting forced umount\n");
622 	if (!fsc)
623 		return;
624 	fsc->mount_state = CEPH_MOUNT_SHUTDOWN;
625 	return;
626 }
627 
628 static const struct super_operations ceph_super_ops = {
629 	.alloc_inode	= ceph_alloc_inode,
630 	.destroy_inode	= ceph_destroy_inode,
631 	.write_inode    = ceph_write_inode,
632 	.sync_fs        = ceph_sync_fs,
633 	.put_super	= ceph_put_super,
634 	.show_options   = ceph_show_options,
635 	.statfs		= ceph_statfs,
636 	.umount_begin   = ceph_umount_begin,
637 };
638 
639 /*
640  * Bootstrap mount by opening the root directory.  Note the mount
641  * @started time from caller, and time out if this takes too long.
642  */
643 static struct dentry *open_root_dentry(struct ceph_fs_client *fsc,
644 				       const char *path,
645 				       unsigned long started)
646 {
647 	struct ceph_mds_client *mdsc = fsc->mdsc;
648 	struct ceph_mds_request *req = NULL;
649 	int err;
650 	struct dentry *root;
651 
652 	/* open dir */
653 	dout("open_root_inode opening '%s'\n", path);
654 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_GETATTR, USE_ANY_MDS);
655 	if (IS_ERR(req))
656 		return ERR_CAST(req);
657 	req->r_path1 = kstrdup(path, GFP_NOFS);
658 	req->r_ino1.ino = CEPH_INO_ROOT;
659 	req->r_ino1.snap = CEPH_NOSNAP;
660 	req->r_started = started;
661 	req->r_timeout = fsc->client->options->mount_timeout * HZ;
662 	req->r_args.getattr.mask = cpu_to_le32(CEPH_STAT_CAP_INODE);
663 	req->r_num_caps = 2;
664 	err = ceph_mdsc_do_request(mdsc, NULL, req);
665 	if (err == 0) {
666 		struct inode *inode = req->r_target_inode;
667 		req->r_target_inode = NULL;
668 		dout("open_root_inode success\n");
669 		if (ceph_ino(inode) == CEPH_INO_ROOT &&
670 		    fsc->sb->s_root == NULL) {
671 			root = d_make_root(inode);
672 			if (!root) {
673 				root = ERR_PTR(-ENOMEM);
674 				goto out;
675 			}
676 		} else {
677 			root = d_obtain_alias(inode);
678 		}
679 		ceph_init_dentry(root);
680 		dout("open_root_inode success, root dentry is %p\n", root);
681 	} else {
682 		root = ERR_PTR(err);
683 	}
684 out:
685 	ceph_mdsc_put_request(req);
686 	return root;
687 }
688 
689 
690 
691 
692 /*
693  * mount: join the ceph cluster, and open root directory.
694  */
695 static struct dentry *ceph_real_mount(struct ceph_fs_client *fsc,
696 		      const char *path)
697 {
698 	int err;
699 	unsigned long started = jiffies;  /* note the start time */
700 	struct dentry *root;
701 	int first = 0;   /* first vfsmount for this super_block */
702 
703 	dout("mount start\n");
704 	mutex_lock(&fsc->client->mount_mutex);
705 
706 	err = __ceph_open_session(fsc->client, started);
707 	if (err < 0)
708 		goto out;
709 
710 	dout("mount opening root\n");
711 	root = open_root_dentry(fsc, "", started);
712 	if (IS_ERR(root)) {
713 		err = PTR_ERR(root);
714 		goto out;
715 	}
716 	if (fsc->sb->s_root) {
717 		dput(root);
718 	} else {
719 		fsc->sb->s_root = root;
720 		first = 1;
721 
722 		err = ceph_fs_debugfs_init(fsc);
723 		if (err < 0)
724 			goto fail;
725 	}
726 
727 	if (path[0] == 0) {
728 		dget(root);
729 	} else {
730 		dout("mount opening base mountpoint\n");
731 		root = open_root_dentry(fsc, path, started);
732 		if (IS_ERR(root)) {
733 			err = PTR_ERR(root);
734 			goto fail;
735 		}
736 	}
737 
738 	fsc->mount_state = CEPH_MOUNT_MOUNTED;
739 	dout("mount success\n");
740 	mutex_unlock(&fsc->client->mount_mutex);
741 	return root;
742 
743 out:
744 	mutex_unlock(&fsc->client->mount_mutex);
745 	return ERR_PTR(err);
746 
747 fail:
748 	if (first) {
749 		dput(fsc->sb->s_root);
750 		fsc->sb->s_root = NULL;
751 	}
752 	goto out;
753 }
754 
755 static int ceph_set_super(struct super_block *s, void *data)
756 {
757 	struct ceph_fs_client *fsc = data;
758 	int ret;
759 
760 	dout("set_super %p data %p\n", s, data);
761 
762 	s->s_flags = fsc->mount_options->sb_flags;
763 	s->s_maxbytes = 1ULL << 40;  /* temp value until we get mdsmap */
764 
765 	s->s_fs_info = fsc;
766 	fsc->sb = s;
767 
768 	s->s_op = &ceph_super_ops;
769 	s->s_export_op = &ceph_export_ops;
770 
771 	s->s_time_gran = 1000;  /* 1000 ns == 1 us */
772 
773 	ret = set_anon_super(s, NULL);  /* what is that second arg for? */
774 	if (ret != 0)
775 		goto fail;
776 
777 	return ret;
778 
779 fail:
780 	s->s_fs_info = NULL;
781 	fsc->sb = NULL;
782 	return ret;
783 }
784 
785 /*
786  * share superblock if same fs AND options
787  */
788 static int ceph_compare_super(struct super_block *sb, void *data)
789 {
790 	struct ceph_fs_client *new = data;
791 	struct ceph_mount_options *fsopt = new->mount_options;
792 	struct ceph_options *opt = new->client->options;
793 	struct ceph_fs_client *other = ceph_sb_to_client(sb);
794 
795 	dout("ceph_compare_super %p\n", sb);
796 
797 	if (compare_mount_options(fsopt, opt, other)) {
798 		dout("monitor(s)/mount options don't match\n");
799 		return 0;
800 	}
801 	if ((opt->flags & CEPH_OPT_FSID) &&
802 	    ceph_fsid_compare(&opt->fsid, &other->client->fsid)) {
803 		dout("fsid doesn't match\n");
804 		return 0;
805 	}
806 	if (fsopt->sb_flags != other->mount_options->sb_flags) {
807 		dout("flags differ\n");
808 		return 0;
809 	}
810 	return 1;
811 }
812 
813 /*
814  * construct our own bdi so we can control readahead, etc.
815  */
816 static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0);
817 
818 static int ceph_register_bdi(struct super_block *sb,
819 			     struct ceph_fs_client *fsc)
820 {
821 	int err;
822 
823 	/* set ra_pages based on rasize mount option? */
824 	if (fsc->mount_options->rasize >= PAGE_CACHE_SIZE)
825 		fsc->backing_dev_info.ra_pages =
826 			(fsc->mount_options->rasize + PAGE_CACHE_SIZE - 1)
827 			>> PAGE_SHIFT;
828 	else
829 		fsc->backing_dev_info.ra_pages =
830 			default_backing_dev_info.ra_pages;
831 
832 	err = bdi_register(&fsc->backing_dev_info, NULL, "ceph-%d",
833 			   atomic_long_inc_return(&bdi_seq));
834 	if (!err)
835 		sb->s_bdi = &fsc->backing_dev_info;
836 	return err;
837 }
838 
839 static struct dentry *ceph_mount(struct file_system_type *fs_type,
840 		       int flags, const char *dev_name, void *data)
841 {
842 	struct super_block *sb;
843 	struct ceph_fs_client *fsc;
844 	struct dentry *res;
845 	int err;
846 	int (*compare_super)(struct super_block *, void *) = ceph_compare_super;
847 	const char *path = NULL;
848 	struct ceph_mount_options *fsopt = NULL;
849 	struct ceph_options *opt = NULL;
850 
851 	dout("ceph_mount\n");
852 	err = parse_mount_options(&fsopt, &opt, flags, data, dev_name, &path);
853 	if (err < 0) {
854 		res = ERR_PTR(err);
855 		goto out_final;
856 	}
857 
858 	/* create client (which we may/may not use) */
859 	fsc = create_fs_client(fsopt, opt);
860 	if (IS_ERR(fsc)) {
861 		res = ERR_CAST(fsc);
862 		destroy_mount_options(fsopt);
863 		ceph_destroy_options(opt);
864 		goto out_final;
865 	}
866 
867 	err = ceph_mdsc_init(fsc);
868 	if (err < 0) {
869 		res = ERR_PTR(err);
870 		goto out;
871 	}
872 
873 	if (ceph_test_opt(fsc->client, NOSHARE))
874 		compare_super = NULL;
875 	sb = sget(fs_type, compare_super, ceph_set_super, flags, fsc);
876 	if (IS_ERR(sb)) {
877 		res = ERR_CAST(sb);
878 		goto out;
879 	}
880 
881 	if (ceph_sb_to_client(sb) != fsc) {
882 		ceph_mdsc_destroy(fsc);
883 		destroy_fs_client(fsc);
884 		fsc = ceph_sb_to_client(sb);
885 		dout("get_sb got existing client %p\n", fsc);
886 	} else {
887 		dout("get_sb using new client %p\n", fsc);
888 		err = ceph_register_bdi(sb, fsc);
889 		if (err < 0) {
890 			res = ERR_PTR(err);
891 			goto out_splat;
892 		}
893 	}
894 
895 	res = ceph_real_mount(fsc, path);
896 	if (IS_ERR(res))
897 		goto out_splat;
898 	dout("root %p inode %p ino %llx.%llx\n", res,
899 	     res->d_inode, ceph_vinop(res->d_inode));
900 	return res;
901 
902 out_splat:
903 	ceph_mdsc_close_sessions(fsc->mdsc);
904 	deactivate_locked_super(sb);
905 	goto out_final;
906 
907 out:
908 	ceph_mdsc_destroy(fsc);
909 	destroy_fs_client(fsc);
910 out_final:
911 	dout("ceph_mount fail %ld\n", PTR_ERR(res));
912 	return res;
913 }
914 
915 static void ceph_kill_sb(struct super_block *s)
916 {
917 	struct ceph_fs_client *fsc = ceph_sb_to_client(s);
918 	dout("kill_sb %p\n", s);
919 	ceph_mdsc_pre_umount(fsc->mdsc);
920 	kill_anon_super(s);    /* will call put_super after sb is r/o */
921 	ceph_mdsc_destroy(fsc);
922 	destroy_fs_client(fsc);
923 }
924 
925 static struct file_system_type ceph_fs_type = {
926 	.owner		= THIS_MODULE,
927 	.name		= "ceph",
928 	.mount		= ceph_mount,
929 	.kill_sb	= ceph_kill_sb,
930 	.fs_flags	= FS_RENAME_DOES_D_MOVE,
931 };
932 
933 #define _STRINGIFY(x) #x
934 #define STRINGIFY(x) _STRINGIFY(x)
935 
936 static int __init init_ceph(void)
937 {
938 	int ret = init_caches();
939 	if (ret)
940 		goto out;
941 
942 	ceph_xattr_init();
943 	ret = register_filesystem(&ceph_fs_type);
944 	if (ret)
945 		goto out_icache;
946 
947 	pr_info("loaded (mds proto %d)\n", CEPH_MDSC_PROTOCOL);
948 
949 	return 0;
950 
951 out_icache:
952 	ceph_xattr_exit();
953 	destroy_caches();
954 out:
955 	return ret;
956 }
957 
958 static void __exit exit_ceph(void)
959 {
960 	dout("exit_ceph\n");
961 	unregister_filesystem(&ceph_fs_type);
962 	ceph_xattr_exit();
963 	destroy_caches();
964 }
965 
966 module_init(init_ceph);
967 module_exit(exit_ceph);
968 
969 MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
970 MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
971 MODULE_AUTHOR("Patience Warnick <patience@newdream.net>");
972 MODULE_DESCRIPTION("Ceph filesystem for Linux");
973 MODULE_LICENSE("GPL");
974