xref: /linux/fs/ceph/super.c (revision 90ab5ee94171b3e28de6bb42ee30b527014e0be7)
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_rasize,
118 	Opt_caps_wanted_delay_min,
119 	Opt_caps_wanted_delay_max,
120 	Opt_cap_release_safety,
121 	Opt_readdir_max_entries,
122 	Opt_readdir_max_bytes,
123 	Opt_congestion_kb,
124 	Opt_last_int,
125 	/* int args above */
126 	Opt_snapdirname,
127 	Opt_last_string,
128 	/* string args above */
129 	Opt_dirstat,
130 	Opt_nodirstat,
131 	Opt_rbytes,
132 	Opt_norbytes,
133 	Opt_noasyncreaddir,
134 	Opt_ino32,
135 };
136 
137 static match_table_t fsopt_tokens = {
138 	{Opt_wsize, "wsize=%d"},
139 	{Opt_rsize, "rsize=%d"},
140 	{Opt_rasize, "rasize=%d"},
141 	{Opt_caps_wanted_delay_min, "caps_wanted_delay_min=%d"},
142 	{Opt_caps_wanted_delay_max, "caps_wanted_delay_max=%d"},
143 	{Opt_cap_release_safety, "cap_release_safety=%d"},
144 	{Opt_readdir_max_entries, "readdir_max_entries=%d"},
145 	{Opt_readdir_max_bytes, "readdir_max_bytes=%d"},
146 	{Opt_congestion_kb, "write_congestion_kb=%d"},
147 	/* int args above */
148 	{Opt_snapdirname, "snapdirname=%s"},
149 	/* string args above */
150 	{Opt_dirstat, "dirstat"},
151 	{Opt_nodirstat, "nodirstat"},
152 	{Opt_rbytes, "rbytes"},
153 	{Opt_norbytes, "norbytes"},
154 	{Opt_noasyncreaddir, "noasyncreaddir"},
155 	{Opt_ino32, "ino32"},
156 	{-1, NULL}
157 };
158 
159 static int parse_fsopt_token(char *c, void *private)
160 {
161 	struct ceph_mount_options *fsopt = private;
162 	substring_t argstr[MAX_OPT_ARGS];
163 	int token, intval, ret;
164 
165 	token = match_token((char *)c, fsopt_tokens, argstr);
166 	if (token < 0)
167 		return -EINVAL;
168 
169 	if (token < Opt_last_int) {
170 		ret = match_int(&argstr[0], &intval);
171 		if (ret < 0) {
172 			pr_err("bad mount option arg (not int) "
173 			       "at '%s'\n", c);
174 			return ret;
175 		}
176 		dout("got int token %d val %d\n", token, intval);
177 	} else if (token > Opt_last_int && token < Opt_last_string) {
178 		dout("got string token %d val %s\n", token,
179 		     argstr[0].from);
180 	} else {
181 		dout("got token %d\n", token);
182 	}
183 
184 	switch (token) {
185 	case Opt_snapdirname:
186 		kfree(fsopt->snapdir_name);
187 		fsopt->snapdir_name = kstrndup(argstr[0].from,
188 					       argstr[0].to-argstr[0].from,
189 					       GFP_KERNEL);
190 		if (!fsopt->snapdir_name)
191 			return -ENOMEM;
192 		break;
193 
194 		/* misc */
195 	case Opt_wsize:
196 		fsopt->wsize = intval;
197 		break;
198 	case Opt_rsize:
199 		fsopt->rsize = intval;
200 		break;
201 	case Opt_rasize:
202 		fsopt->rasize = intval;
203 		break;
204 	case Opt_caps_wanted_delay_min:
205 		fsopt->caps_wanted_delay_min = intval;
206 		break;
207 	case Opt_caps_wanted_delay_max:
208 		fsopt->caps_wanted_delay_max = intval;
209 		break;
210 	case Opt_readdir_max_entries:
211 		fsopt->max_readdir = intval;
212 		break;
213 	case Opt_readdir_max_bytes:
214 		fsopt->max_readdir_bytes = intval;
215 		break;
216 	case Opt_congestion_kb:
217 		fsopt->congestion_kb = intval;
218 		break;
219 	case Opt_dirstat:
220 		fsopt->flags |= CEPH_MOUNT_OPT_DIRSTAT;
221 		break;
222 	case Opt_nodirstat:
223 		fsopt->flags &= ~CEPH_MOUNT_OPT_DIRSTAT;
224 		break;
225 	case Opt_rbytes:
226 		fsopt->flags |= CEPH_MOUNT_OPT_RBYTES;
227 		break;
228 	case Opt_norbytes:
229 		fsopt->flags &= ~CEPH_MOUNT_OPT_RBYTES;
230 		break;
231 	case Opt_noasyncreaddir:
232 		fsopt->flags |= CEPH_MOUNT_OPT_NOASYNCREADDIR;
233 		break;
234 	case Opt_ino32:
235 		fsopt->flags |= CEPH_MOUNT_OPT_INO32;
236 		break;
237 	default:
238 		BUG_ON(token);
239 	}
240 	return 0;
241 }
242 
243 static void destroy_mount_options(struct ceph_mount_options *args)
244 {
245 	dout("destroy_mount_options %p\n", args);
246 	kfree(args->snapdir_name);
247 	kfree(args);
248 }
249 
250 static int strcmp_null(const char *s1, const char *s2)
251 {
252 	if (!s1 && !s2)
253 		return 0;
254 	if (s1 && !s2)
255 		return -1;
256 	if (!s1 && s2)
257 		return 1;
258 	return strcmp(s1, s2);
259 }
260 
261 static int compare_mount_options(struct ceph_mount_options *new_fsopt,
262 				 struct ceph_options *new_opt,
263 				 struct ceph_fs_client *fsc)
264 {
265 	struct ceph_mount_options *fsopt1 = new_fsopt;
266 	struct ceph_mount_options *fsopt2 = fsc->mount_options;
267 	int ofs = offsetof(struct ceph_mount_options, snapdir_name);
268 	int ret;
269 
270 	ret = memcmp(fsopt1, fsopt2, ofs);
271 	if (ret)
272 		return ret;
273 
274 	ret = strcmp_null(fsopt1->snapdir_name, fsopt2->snapdir_name);
275 	if (ret)
276 		return ret;
277 
278 	return ceph_compare_options(new_opt, fsc->client);
279 }
280 
281 static int parse_mount_options(struct ceph_mount_options **pfsopt,
282 			       struct ceph_options **popt,
283 			       int flags, char *options,
284 			       const char *dev_name,
285 			       const char **path)
286 {
287 	struct ceph_mount_options *fsopt;
288 	const char *dev_name_end;
289 	int err = -ENOMEM;
290 
291 	fsopt = kzalloc(sizeof(*fsopt), GFP_KERNEL);
292 	if (!fsopt)
293 		return -ENOMEM;
294 
295 	dout("parse_mount_options %p, dev_name '%s'\n", fsopt, dev_name);
296 
297 	fsopt->sb_flags = flags;
298 	fsopt->flags = CEPH_MOUNT_OPT_DEFAULT;
299 
300 	fsopt->rsize = CEPH_RSIZE_DEFAULT;
301 	fsopt->rasize = CEPH_RASIZE_DEFAULT;
302 	fsopt->snapdir_name = kstrdup(CEPH_SNAPDIRNAME_DEFAULT, GFP_KERNEL);
303 	fsopt->caps_wanted_delay_min = CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT;
304 	fsopt->caps_wanted_delay_max = CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT;
305 	fsopt->cap_release_safety = CEPH_CAP_RELEASE_SAFETY_DEFAULT;
306 	fsopt->max_readdir = CEPH_MAX_READDIR_DEFAULT;
307 	fsopt->max_readdir_bytes = CEPH_MAX_READDIR_BYTES_DEFAULT;
308 	fsopt->congestion_kb = default_congestion_kb();
309 
310 	/* ip1[:port1][,ip2[:port2]...]:/subdir/in/fs */
311 	err = -EINVAL;
312 	if (!dev_name)
313 		goto out;
314 	*path = strstr(dev_name, ":/");
315 	if (*path == NULL) {
316 		pr_err("device name is missing path (no :/ in %s)\n",
317 				dev_name);
318 		goto out;
319 	}
320 	dev_name_end = *path;
321 	dout("device name '%.*s'\n", (int)(dev_name_end - dev_name), dev_name);
322 
323 	/* path on server */
324 	*path += 2;
325 	dout("server path '%s'\n", *path);
326 
327 	err = ceph_parse_options(popt, options, dev_name, dev_name_end,
328 				 parse_fsopt_token, (void *)fsopt);
329 	if (err)
330 		goto out;
331 
332 	/* success */
333 	*pfsopt = fsopt;
334 	return 0;
335 
336 out:
337 	destroy_mount_options(fsopt);
338 	return err;
339 }
340 
341 /**
342  * ceph_show_options - Show mount options in /proc/mounts
343  * @m: seq_file to write to
344  * @root: root of that (sub)tree
345  */
346 static int ceph_show_options(struct seq_file *m, struct dentry *root)
347 {
348 	struct ceph_fs_client *fsc = ceph_sb_to_client(root->d_sb);
349 	struct ceph_mount_options *fsopt = fsc->mount_options;
350 	struct ceph_options *opt = fsc->client->options;
351 
352 	if (opt->flags & CEPH_OPT_FSID)
353 		seq_printf(m, ",fsid=%pU", &opt->fsid);
354 	if (opt->flags & CEPH_OPT_NOSHARE)
355 		seq_puts(m, ",noshare");
356 	if (opt->flags & CEPH_OPT_NOCRC)
357 		seq_puts(m, ",nocrc");
358 
359 	if (opt->name)
360 		seq_printf(m, ",name=%s", opt->name);
361 	if (opt->key)
362 		seq_puts(m, ",secret=<hidden>");
363 
364 	if (opt->mount_timeout != CEPH_MOUNT_TIMEOUT_DEFAULT)
365 		seq_printf(m, ",mount_timeout=%d", opt->mount_timeout);
366 	if (opt->osd_idle_ttl != CEPH_OSD_IDLE_TTL_DEFAULT)
367 		seq_printf(m, ",osd_idle_ttl=%d", opt->osd_idle_ttl);
368 	if (opt->osd_timeout != CEPH_OSD_TIMEOUT_DEFAULT)
369 		seq_printf(m, ",osdtimeout=%d", opt->osd_timeout);
370 	if (opt->osd_keepalive_timeout != CEPH_OSD_KEEPALIVE_DEFAULT)
371 		seq_printf(m, ",osdkeepalivetimeout=%d",
372 			   opt->osd_keepalive_timeout);
373 
374 	if (fsopt->flags & CEPH_MOUNT_OPT_DIRSTAT)
375 		seq_puts(m, ",dirstat");
376 	if ((fsopt->flags & CEPH_MOUNT_OPT_RBYTES) == 0)
377 		seq_puts(m, ",norbytes");
378 	if (fsopt->flags & CEPH_MOUNT_OPT_NOASYNCREADDIR)
379 		seq_puts(m, ",noasyncreaddir");
380 
381 	if (fsopt->wsize)
382 		seq_printf(m, ",wsize=%d", fsopt->wsize);
383 	if (fsopt->rsize != CEPH_RSIZE_DEFAULT)
384 		seq_printf(m, ",rsize=%d", fsopt->rsize);
385 	if (fsopt->rasize != CEPH_RASIZE_DEFAULT)
386 		seq_printf(m, ",rasize=%d", fsopt->rasize);
387 	if (fsopt->congestion_kb != default_congestion_kb())
388 		seq_printf(m, ",write_congestion_kb=%d", fsopt->congestion_kb);
389 	if (fsopt->caps_wanted_delay_min != CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT)
390 		seq_printf(m, ",caps_wanted_delay_min=%d",
391 			 fsopt->caps_wanted_delay_min);
392 	if (fsopt->caps_wanted_delay_max != CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT)
393 		seq_printf(m, ",caps_wanted_delay_max=%d",
394 			   fsopt->caps_wanted_delay_max);
395 	if (fsopt->cap_release_safety != CEPH_CAP_RELEASE_SAFETY_DEFAULT)
396 		seq_printf(m, ",cap_release_safety=%d",
397 			   fsopt->cap_release_safety);
398 	if (fsopt->max_readdir != CEPH_MAX_READDIR_DEFAULT)
399 		seq_printf(m, ",readdir_max_entries=%d", fsopt->max_readdir);
400 	if (fsopt->max_readdir_bytes != CEPH_MAX_READDIR_BYTES_DEFAULT)
401 		seq_printf(m, ",readdir_max_bytes=%d", fsopt->max_readdir_bytes);
402 	if (strcmp(fsopt->snapdir_name, CEPH_SNAPDIRNAME_DEFAULT))
403 		seq_printf(m, ",snapdirname=%s", fsopt->snapdir_name);
404 	return 0;
405 }
406 
407 /*
408  * handle any mon messages the standard library doesn't understand.
409  * return error if we don't either.
410  */
411 static int extra_mon_dispatch(struct ceph_client *client, struct ceph_msg *msg)
412 {
413 	struct ceph_fs_client *fsc = client->private;
414 	int type = le16_to_cpu(msg->hdr.type);
415 
416 	switch (type) {
417 	case CEPH_MSG_MDS_MAP:
418 		ceph_mdsc_handle_map(fsc->mdsc, msg);
419 		return 0;
420 
421 	default:
422 		return -1;
423 	}
424 }
425 
426 /*
427  * create a new fs client
428  */
429 static struct ceph_fs_client *create_fs_client(struct ceph_mount_options *fsopt,
430 					struct ceph_options *opt)
431 {
432 	struct ceph_fs_client *fsc;
433 	const unsigned supported_features =
434 		CEPH_FEATURE_FLOCK |
435 		CEPH_FEATURE_DIRLAYOUTHASH;
436 	const unsigned required_features = 0;
437 	int err = -ENOMEM;
438 
439 	fsc = kzalloc(sizeof(*fsc), GFP_KERNEL);
440 	if (!fsc)
441 		return ERR_PTR(-ENOMEM);
442 
443 	fsc->client = ceph_create_client(opt, fsc, supported_features,
444 					 required_features);
445 	if (IS_ERR(fsc->client)) {
446 		err = PTR_ERR(fsc->client);
447 		goto fail;
448 	}
449 	fsc->client->extra_mon_dispatch = extra_mon_dispatch;
450 	fsc->client->monc.want_mdsmap = 1;
451 
452 	fsc->mount_options = fsopt;
453 
454 	fsc->sb = NULL;
455 	fsc->mount_state = CEPH_MOUNT_MOUNTING;
456 
457 	atomic_long_set(&fsc->writeback_count, 0);
458 
459 	err = bdi_init(&fsc->backing_dev_info);
460 	if (err < 0)
461 		goto fail_client;
462 
463 	err = -ENOMEM;
464 	/*
465 	 * The number of concurrent works can be high but they don't need
466 	 * to be processed in parallel, limit concurrency.
467 	 */
468 	fsc->wb_wq = alloc_workqueue("ceph-writeback", 0, 1);
469 	if (fsc->wb_wq == NULL)
470 		goto fail_bdi;
471 	fsc->pg_inv_wq = alloc_workqueue("ceph-pg-invalid", 0, 1);
472 	if (fsc->pg_inv_wq == NULL)
473 		goto fail_wb_wq;
474 	fsc->trunc_wq = alloc_workqueue("ceph-trunc", 0, 1);
475 	if (fsc->trunc_wq == NULL)
476 		goto fail_pg_inv_wq;
477 
478 	/* set up mempools */
479 	err = -ENOMEM;
480 	fsc->wb_pagevec_pool = mempool_create_kmalloc_pool(10,
481 			      fsc->mount_options->wsize >> PAGE_CACHE_SHIFT);
482 	if (!fsc->wb_pagevec_pool)
483 		goto fail_trunc_wq;
484 
485 	/* caps */
486 	fsc->min_caps = fsopt->max_readdir;
487 
488 	return fsc;
489 
490 fail_trunc_wq:
491 	destroy_workqueue(fsc->trunc_wq);
492 fail_pg_inv_wq:
493 	destroy_workqueue(fsc->pg_inv_wq);
494 fail_wb_wq:
495 	destroy_workqueue(fsc->wb_wq);
496 fail_bdi:
497 	bdi_destroy(&fsc->backing_dev_info);
498 fail_client:
499 	ceph_destroy_client(fsc->client);
500 fail:
501 	kfree(fsc);
502 	return ERR_PTR(err);
503 }
504 
505 static void destroy_fs_client(struct ceph_fs_client *fsc)
506 {
507 	dout("destroy_fs_client %p\n", fsc);
508 
509 	destroy_workqueue(fsc->wb_wq);
510 	destroy_workqueue(fsc->pg_inv_wq);
511 	destroy_workqueue(fsc->trunc_wq);
512 
513 	bdi_destroy(&fsc->backing_dev_info);
514 
515 	mempool_destroy(fsc->wb_pagevec_pool);
516 
517 	destroy_mount_options(fsc->mount_options);
518 
519 	ceph_fs_debugfs_cleanup(fsc);
520 
521 	ceph_destroy_client(fsc->client);
522 
523 	kfree(fsc);
524 	dout("destroy_fs_client %p done\n", fsc);
525 }
526 
527 /*
528  * caches
529  */
530 struct kmem_cache *ceph_inode_cachep;
531 struct kmem_cache *ceph_cap_cachep;
532 struct kmem_cache *ceph_dentry_cachep;
533 struct kmem_cache *ceph_file_cachep;
534 
535 static void ceph_inode_init_once(void *foo)
536 {
537 	struct ceph_inode_info *ci = foo;
538 	inode_init_once(&ci->vfs_inode);
539 }
540 
541 static int __init init_caches(void)
542 {
543 	ceph_inode_cachep = kmem_cache_create("ceph_inode_info",
544 				      sizeof(struct ceph_inode_info),
545 				      __alignof__(struct ceph_inode_info),
546 				      (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD),
547 				      ceph_inode_init_once);
548 	if (ceph_inode_cachep == NULL)
549 		return -ENOMEM;
550 
551 	ceph_cap_cachep = KMEM_CACHE(ceph_cap,
552 				     SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
553 	if (ceph_cap_cachep == NULL)
554 		goto bad_cap;
555 
556 	ceph_dentry_cachep = KMEM_CACHE(ceph_dentry_info,
557 					SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
558 	if (ceph_dentry_cachep == NULL)
559 		goto bad_dentry;
560 
561 	ceph_file_cachep = KMEM_CACHE(ceph_file_info,
562 				      SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
563 	if (ceph_file_cachep == NULL)
564 		goto bad_file;
565 
566 	return 0;
567 
568 bad_file:
569 	kmem_cache_destroy(ceph_dentry_cachep);
570 bad_dentry:
571 	kmem_cache_destroy(ceph_cap_cachep);
572 bad_cap:
573 	kmem_cache_destroy(ceph_inode_cachep);
574 	return -ENOMEM;
575 }
576 
577 static void destroy_caches(void)
578 {
579 	kmem_cache_destroy(ceph_inode_cachep);
580 	kmem_cache_destroy(ceph_cap_cachep);
581 	kmem_cache_destroy(ceph_dentry_cachep);
582 	kmem_cache_destroy(ceph_file_cachep);
583 }
584 
585 
586 /*
587  * ceph_umount_begin - initiate forced umount.  Tear down down the
588  * mount, skipping steps that may hang while waiting for server(s).
589  */
590 static void ceph_umount_begin(struct super_block *sb)
591 {
592 	struct ceph_fs_client *fsc = ceph_sb_to_client(sb);
593 
594 	dout("ceph_umount_begin - starting forced umount\n");
595 	if (!fsc)
596 		return;
597 	fsc->mount_state = CEPH_MOUNT_SHUTDOWN;
598 	return;
599 }
600 
601 static const struct super_operations ceph_super_ops = {
602 	.alloc_inode	= ceph_alloc_inode,
603 	.destroy_inode	= ceph_destroy_inode,
604 	.write_inode    = ceph_write_inode,
605 	.sync_fs        = ceph_sync_fs,
606 	.put_super	= ceph_put_super,
607 	.show_options   = ceph_show_options,
608 	.statfs		= ceph_statfs,
609 	.umount_begin   = ceph_umount_begin,
610 };
611 
612 /*
613  * Bootstrap mount by opening the root directory.  Note the mount
614  * @started time from caller, and time out if this takes too long.
615  */
616 static struct dentry *open_root_dentry(struct ceph_fs_client *fsc,
617 				       const char *path,
618 				       unsigned long started)
619 {
620 	struct ceph_mds_client *mdsc = fsc->mdsc;
621 	struct ceph_mds_request *req = NULL;
622 	int err;
623 	struct dentry *root;
624 
625 	/* open dir */
626 	dout("open_root_inode opening '%s'\n", path);
627 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_GETATTR, USE_ANY_MDS);
628 	if (IS_ERR(req))
629 		return ERR_CAST(req);
630 	req->r_path1 = kstrdup(path, GFP_NOFS);
631 	req->r_ino1.ino = CEPH_INO_ROOT;
632 	req->r_ino1.snap = CEPH_NOSNAP;
633 	req->r_started = started;
634 	req->r_timeout = fsc->client->options->mount_timeout * HZ;
635 	req->r_args.getattr.mask = cpu_to_le32(CEPH_STAT_CAP_INODE);
636 	req->r_num_caps = 2;
637 	err = ceph_mdsc_do_request(mdsc, NULL, req);
638 	if (err == 0) {
639 		struct inode *inode = req->r_target_inode;
640 		req->r_target_inode = NULL;
641 		dout("open_root_inode success\n");
642 		if (ceph_ino(inode) == CEPH_INO_ROOT &&
643 		    fsc->sb->s_root == NULL) {
644 			root = d_alloc_root(inode);
645 			if (!root) {
646 				iput(inode);
647 				root = ERR_PTR(-ENOMEM);
648 				goto out;
649 			}
650 			ceph_init_dentry(root);
651 		} else {
652 			root = d_obtain_alias(inode);
653 		}
654 		dout("open_root_inode success, root dentry is %p\n", root);
655 	} else {
656 		root = ERR_PTR(err);
657 	}
658 out:
659 	ceph_mdsc_put_request(req);
660 	return root;
661 }
662 
663 
664 
665 
666 /*
667  * mount: join the ceph cluster, and open root directory.
668  */
669 static struct dentry *ceph_real_mount(struct ceph_fs_client *fsc,
670 		      const char *path)
671 {
672 	int err;
673 	unsigned long started = jiffies;  /* note the start time */
674 	struct dentry *root;
675 	int first = 0;   /* first vfsmount for this super_block */
676 
677 	dout("mount start\n");
678 	mutex_lock(&fsc->client->mount_mutex);
679 
680 	err = __ceph_open_session(fsc->client, started);
681 	if (err < 0)
682 		goto out;
683 
684 	dout("mount opening root\n");
685 	root = open_root_dentry(fsc, "", started);
686 	if (IS_ERR(root)) {
687 		err = PTR_ERR(root);
688 		goto out;
689 	}
690 	if (fsc->sb->s_root) {
691 		dput(root);
692 	} else {
693 		fsc->sb->s_root = root;
694 		first = 1;
695 
696 		err = ceph_fs_debugfs_init(fsc);
697 		if (err < 0)
698 			goto fail;
699 	}
700 
701 	if (path[0] == 0) {
702 		dget(root);
703 	} else {
704 		dout("mount opening base mountpoint\n");
705 		root = open_root_dentry(fsc, path, started);
706 		if (IS_ERR(root)) {
707 			err = PTR_ERR(root);
708 			goto fail;
709 		}
710 	}
711 
712 	fsc->mount_state = CEPH_MOUNT_MOUNTED;
713 	dout("mount success\n");
714 	mutex_unlock(&fsc->client->mount_mutex);
715 	return root;
716 
717 out:
718 	mutex_unlock(&fsc->client->mount_mutex);
719 	return ERR_PTR(err);
720 
721 fail:
722 	if (first) {
723 		dput(fsc->sb->s_root);
724 		fsc->sb->s_root = NULL;
725 	}
726 	goto out;
727 }
728 
729 static int ceph_set_super(struct super_block *s, void *data)
730 {
731 	struct ceph_fs_client *fsc = data;
732 	int ret;
733 
734 	dout("set_super %p data %p\n", s, data);
735 
736 	s->s_flags = fsc->mount_options->sb_flags;
737 	s->s_maxbytes = 1ULL << 40;  /* temp value until we get mdsmap */
738 
739 	s->s_fs_info = fsc;
740 	fsc->sb = s;
741 
742 	s->s_op = &ceph_super_ops;
743 	s->s_export_op = &ceph_export_ops;
744 
745 	s->s_time_gran = 1000;  /* 1000 ns == 1 us */
746 
747 	ret = set_anon_super(s, NULL);  /* what is that second arg for? */
748 	if (ret != 0)
749 		goto fail;
750 
751 	return ret;
752 
753 fail:
754 	s->s_fs_info = NULL;
755 	fsc->sb = NULL;
756 	return ret;
757 }
758 
759 /*
760  * share superblock if same fs AND options
761  */
762 static int ceph_compare_super(struct super_block *sb, void *data)
763 {
764 	struct ceph_fs_client *new = data;
765 	struct ceph_mount_options *fsopt = new->mount_options;
766 	struct ceph_options *opt = new->client->options;
767 	struct ceph_fs_client *other = ceph_sb_to_client(sb);
768 
769 	dout("ceph_compare_super %p\n", sb);
770 
771 	if (compare_mount_options(fsopt, opt, other)) {
772 		dout("monitor(s)/mount options don't match\n");
773 		return 0;
774 	}
775 	if ((opt->flags & CEPH_OPT_FSID) &&
776 	    ceph_fsid_compare(&opt->fsid, &other->client->fsid)) {
777 		dout("fsid doesn't match\n");
778 		return 0;
779 	}
780 	if (fsopt->sb_flags != other->mount_options->sb_flags) {
781 		dout("flags differ\n");
782 		return 0;
783 	}
784 	return 1;
785 }
786 
787 /*
788  * construct our own bdi so we can control readahead, etc.
789  */
790 static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0);
791 
792 static int ceph_register_bdi(struct super_block *sb,
793 			     struct ceph_fs_client *fsc)
794 {
795 	int err;
796 
797 	/* set ra_pages based on rasize mount option? */
798 	if (fsc->mount_options->rasize >= PAGE_CACHE_SIZE)
799 		fsc->backing_dev_info.ra_pages =
800 			(fsc->mount_options->rasize + PAGE_CACHE_SIZE - 1)
801 			>> PAGE_SHIFT;
802 	else
803 		fsc->backing_dev_info.ra_pages =
804 			default_backing_dev_info.ra_pages;
805 
806 	err = bdi_register(&fsc->backing_dev_info, NULL, "ceph-%d",
807 			   atomic_long_inc_return(&bdi_seq));
808 	if (!err)
809 		sb->s_bdi = &fsc->backing_dev_info;
810 	return err;
811 }
812 
813 static struct dentry *ceph_mount(struct file_system_type *fs_type,
814 		       int flags, const char *dev_name, void *data)
815 {
816 	struct super_block *sb;
817 	struct ceph_fs_client *fsc;
818 	struct dentry *res;
819 	int err;
820 	int (*compare_super)(struct super_block *, void *) = ceph_compare_super;
821 	const char *path = NULL;
822 	struct ceph_mount_options *fsopt = NULL;
823 	struct ceph_options *opt = NULL;
824 
825 	dout("ceph_mount\n");
826 	err = parse_mount_options(&fsopt, &opt, flags, data, dev_name, &path);
827 	if (err < 0) {
828 		res = ERR_PTR(err);
829 		goto out_final;
830 	}
831 
832 	/* create client (which we may/may not use) */
833 	fsc = create_fs_client(fsopt, opt);
834 	if (IS_ERR(fsc)) {
835 		res = ERR_CAST(fsc);
836 		destroy_mount_options(fsopt);
837 		ceph_destroy_options(opt);
838 		goto out_final;
839 	}
840 
841 	err = ceph_mdsc_init(fsc);
842 	if (err < 0) {
843 		res = ERR_PTR(err);
844 		goto out;
845 	}
846 
847 	if (ceph_test_opt(fsc->client, NOSHARE))
848 		compare_super = NULL;
849 	sb = sget(fs_type, compare_super, ceph_set_super, fsc);
850 	if (IS_ERR(sb)) {
851 		res = ERR_CAST(sb);
852 		goto out;
853 	}
854 
855 	if (ceph_sb_to_client(sb) != fsc) {
856 		ceph_mdsc_destroy(fsc);
857 		destroy_fs_client(fsc);
858 		fsc = ceph_sb_to_client(sb);
859 		dout("get_sb got existing client %p\n", fsc);
860 	} else {
861 		dout("get_sb using new client %p\n", fsc);
862 		err = ceph_register_bdi(sb, fsc);
863 		if (err < 0) {
864 			res = ERR_PTR(err);
865 			goto out_splat;
866 		}
867 	}
868 
869 	res = ceph_real_mount(fsc, path);
870 	if (IS_ERR(res))
871 		goto out_splat;
872 	dout("root %p inode %p ino %llx.%llx\n", res,
873 	     res->d_inode, ceph_vinop(res->d_inode));
874 	return res;
875 
876 out_splat:
877 	ceph_mdsc_close_sessions(fsc->mdsc);
878 	deactivate_locked_super(sb);
879 	goto out_final;
880 
881 out:
882 	ceph_mdsc_destroy(fsc);
883 	destroy_fs_client(fsc);
884 out_final:
885 	dout("ceph_mount fail %ld\n", PTR_ERR(res));
886 	return res;
887 }
888 
889 static void ceph_kill_sb(struct super_block *s)
890 {
891 	struct ceph_fs_client *fsc = ceph_sb_to_client(s);
892 	dout("kill_sb %p\n", s);
893 	ceph_mdsc_pre_umount(fsc->mdsc);
894 	kill_anon_super(s);    /* will call put_super after sb is r/o */
895 	ceph_mdsc_destroy(fsc);
896 	destroy_fs_client(fsc);
897 }
898 
899 static struct file_system_type ceph_fs_type = {
900 	.owner		= THIS_MODULE,
901 	.name		= "ceph",
902 	.mount		= ceph_mount,
903 	.kill_sb	= ceph_kill_sb,
904 	.fs_flags	= FS_RENAME_DOES_D_MOVE,
905 };
906 
907 #define _STRINGIFY(x) #x
908 #define STRINGIFY(x) _STRINGIFY(x)
909 
910 static int __init init_ceph(void)
911 {
912 	int ret = init_caches();
913 	if (ret)
914 		goto out;
915 
916 	ret = register_filesystem(&ceph_fs_type);
917 	if (ret)
918 		goto out_icache;
919 
920 	pr_info("loaded (mds proto %d)\n", CEPH_MDSC_PROTOCOL);
921 
922 	return 0;
923 
924 out_icache:
925 	destroy_caches();
926 out:
927 	return ret;
928 }
929 
930 static void __exit exit_ceph(void)
931 {
932 	dout("exit_ceph\n");
933 	unregister_filesystem(&ceph_fs_type);
934 	destroy_caches();
935 }
936 
937 module_init(init_ceph);
938 module_exit(exit_ceph);
939 
940 MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
941 MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
942 MODULE_AUTHOR("Patience Warnick <patience@newdream.net>");
943 MODULE_DESCRIPTION("Ceph filesystem for Linux");
944 MODULE_LICENSE("GPL");
945