xref: /linux/fs/ceph/super.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
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 #include "cache.h"
21 
22 #include <linux/ceph/ceph_features.h>
23 #include <linux/ceph/decode.h>
24 #include <linux/ceph/mon_client.h>
25 #include <linux/ceph/auth.h>
26 #include <linux/ceph/debugfs.h>
27 
28 /*
29  * Ceph superblock operations
30  *
31  * Handle the basics of mounting, unmounting.
32  */
33 
34 /*
35  * super ops
36  */
37 static void ceph_put_super(struct super_block *s)
38 {
39 	struct ceph_fs_client *fsc = ceph_sb_to_client(s);
40 
41 	dout("put_super\n");
42 	ceph_mdsc_close_sessions(fsc->mdsc);
43 }
44 
45 static int ceph_statfs(struct dentry *dentry, struct kstatfs *buf)
46 {
47 	struct ceph_fs_client *fsc = ceph_inode_to_client(d_inode(dentry));
48 	struct ceph_monmap *monmap = fsc->client->monc.monmap;
49 	struct ceph_statfs st;
50 	u64 fsid;
51 	int err;
52 
53 	dout("statfs\n");
54 	err = ceph_monc_do_statfs(&fsc->client->monc, &st);
55 	if (err < 0)
56 		return err;
57 
58 	/* fill in kstatfs */
59 	buf->f_type = CEPH_SUPER_MAGIC;  /* ?? */
60 
61 	/*
62 	 * express utilization in terms of large blocks to avoid
63 	 * overflow on 32-bit machines.
64 	 *
65 	 * NOTE: for the time being, we make bsize == frsize to humor
66 	 * not-yet-ancient versions of glibc that are broken.
67 	 * Someday, we will probably want to report a real block
68 	 * size...  whatever that may mean for a network file system!
69 	 */
70 	buf->f_bsize = 1 << CEPH_BLOCK_SHIFT;
71 	buf->f_frsize = 1 << CEPH_BLOCK_SHIFT;
72 	buf->f_blocks = le64_to_cpu(st.kb) >> (CEPH_BLOCK_SHIFT-10);
73 	buf->f_bfree = le64_to_cpu(st.kb_avail) >> (CEPH_BLOCK_SHIFT-10);
74 	buf->f_bavail = le64_to_cpu(st.kb_avail) >> (CEPH_BLOCK_SHIFT-10);
75 
76 	buf->f_files = le64_to_cpu(st.num_objects);
77 	buf->f_ffree = -1;
78 	buf->f_namelen = NAME_MAX;
79 
80 	/* leave fsid little-endian, regardless of host endianness */
81 	fsid = *(u64 *)(&monmap->fsid) ^ *((u64 *)&monmap->fsid + 1);
82 	buf->f_fsid.val[0] = fsid & 0xffffffff;
83 	buf->f_fsid.val[1] = fsid >> 32;
84 
85 	return 0;
86 }
87 
88 
89 static int ceph_sync_fs(struct super_block *sb, int wait)
90 {
91 	struct ceph_fs_client *fsc = ceph_sb_to_client(sb);
92 
93 	if (!wait) {
94 		dout("sync_fs (non-blocking)\n");
95 		ceph_flush_dirty_caps(fsc->mdsc);
96 		dout("sync_fs (non-blocking) done\n");
97 		return 0;
98 	}
99 
100 	dout("sync_fs (blocking)\n");
101 	ceph_osdc_sync(&fsc->client->osdc);
102 	ceph_mdsc_sync(fsc->mdsc);
103 	dout("sync_fs (blocking) done\n");
104 	return 0;
105 }
106 
107 /*
108  * mount options
109  */
110 enum {
111 	Opt_wsize,
112 	Opt_rsize,
113 	Opt_rasize,
114 	Opt_caps_wanted_delay_min,
115 	Opt_caps_wanted_delay_max,
116 	Opt_cap_release_safety,
117 	Opt_readdir_max_entries,
118 	Opt_readdir_max_bytes,
119 	Opt_congestion_kb,
120 	Opt_last_int,
121 	/* int args above */
122 	Opt_snapdirname,
123 	Opt_last_string,
124 	/* string args above */
125 	Opt_dirstat,
126 	Opt_nodirstat,
127 	Opt_rbytes,
128 	Opt_norbytes,
129 	Opt_asyncreaddir,
130 	Opt_noasyncreaddir,
131 	Opt_dcache,
132 	Opt_nodcache,
133 	Opt_ino32,
134 	Opt_noino32,
135 	Opt_fscache,
136 	Opt_nofscache,
137 	Opt_poolperm,
138 	Opt_nopoolperm,
139 #ifdef CONFIG_CEPH_FS_POSIX_ACL
140 	Opt_acl,
141 #endif
142 	Opt_noacl,
143 };
144 
145 static match_table_t fsopt_tokens = {
146 	{Opt_wsize, "wsize=%d"},
147 	{Opt_rsize, "rsize=%d"},
148 	{Opt_rasize, "rasize=%d"},
149 	{Opt_caps_wanted_delay_min, "caps_wanted_delay_min=%d"},
150 	{Opt_caps_wanted_delay_max, "caps_wanted_delay_max=%d"},
151 	{Opt_cap_release_safety, "cap_release_safety=%d"},
152 	{Opt_readdir_max_entries, "readdir_max_entries=%d"},
153 	{Opt_readdir_max_bytes, "readdir_max_bytes=%d"},
154 	{Opt_congestion_kb, "write_congestion_kb=%d"},
155 	/* int args above */
156 	{Opt_snapdirname, "snapdirname=%s"},
157 	/* string args above */
158 	{Opt_dirstat, "dirstat"},
159 	{Opt_nodirstat, "nodirstat"},
160 	{Opt_rbytes, "rbytes"},
161 	{Opt_norbytes, "norbytes"},
162 	{Opt_asyncreaddir, "asyncreaddir"},
163 	{Opt_noasyncreaddir, "noasyncreaddir"},
164 	{Opt_dcache, "dcache"},
165 	{Opt_nodcache, "nodcache"},
166 	{Opt_ino32, "ino32"},
167 	{Opt_noino32, "noino32"},
168 	{Opt_fscache, "fsc"},
169 	{Opt_nofscache, "nofsc"},
170 	{Opt_poolperm, "poolperm"},
171 	{Opt_nopoolperm, "nopoolperm"},
172 #ifdef CONFIG_CEPH_FS_POSIX_ACL
173 	{Opt_acl, "acl"},
174 #endif
175 	{Opt_noacl, "noacl"},
176 	{-1, NULL}
177 };
178 
179 static int parse_fsopt_token(char *c, void *private)
180 {
181 	struct ceph_mount_options *fsopt = private;
182 	substring_t argstr[MAX_OPT_ARGS];
183 	int token, intval, ret;
184 
185 	token = match_token((char *)c, fsopt_tokens, argstr);
186 	if (token < 0)
187 		return -EINVAL;
188 
189 	if (token < Opt_last_int) {
190 		ret = match_int(&argstr[0], &intval);
191 		if (ret < 0) {
192 			pr_err("bad mount option arg (not int) "
193 			       "at '%s'\n", c);
194 			return ret;
195 		}
196 		dout("got int token %d val %d\n", token, intval);
197 	} else if (token > Opt_last_int && token < Opt_last_string) {
198 		dout("got string token %d val %s\n", token,
199 		     argstr[0].from);
200 	} else {
201 		dout("got token %d\n", token);
202 	}
203 
204 	switch (token) {
205 	case Opt_snapdirname:
206 		kfree(fsopt->snapdir_name);
207 		fsopt->snapdir_name = kstrndup(argstr[0].from,
208 					       argstr[0].to-argstr[0].from,
209 					       GFP_KERNEL);
210 		if (!fsopt->snapdir_name)
211 			return -ENOMEM;
212 		break;
213 
214 		/* misc */
215 	case Opt_wsize:
216 		fsopt->wsize = intval;
217 		break;
218 	case Opt_rsize:
219 		fsopt->rsize = intval;
220 		break;
221 	case Opt_rasize:
222 		fsopt->rasize = intval;
223 		break;
224 	case Opt_caps_wanted_delay_min:
225 		fsopt->caps_wanted_delay_min = intval;
226 		break;
227 	case Opt_caps_wanted_delay_max:
228 		fsopt->caps_wanted_delay_max = intval;
229 		break;
230 	case Opt_readdir_max_entries:
231 		fsopt->max_readdir = intval;
232 		break;
233 	case Opt_readdir_max_bytes:
234 		fsopt->max_readdir_bytes = intval;
235 		break;
236 	case Opt_congestion_kb:
237 		fsopt->congestion_kb = intval;
238 		break;
239 	case Opt_dirstat:
240 		fsopt->flags |= CEPH_MOUNT_OPT_DIRSTAT;
241 		break;
242 	case Opt_nodirstat:
243 		fsopt->flags &= ~CEPH_MOUNT_OPT_DIRSTAT;
244 		break;
245 	case Opt_rbytes:
246 		fsopt->flags |= CEPH_MOUNT_OPT_RBYTES;
247 		break;
248 	case Opt_norbytes:
249 		fsopt->flags &= ~CEPH_MOUNT_OPT_RBYTES;
250 		break;
251 	case Opt_asyncreaddir:
252 		fsopt->flags &= ~CEPH_MOUNT_OPT_NOASYNCREADDIR;
253 		break;
254 	case Opt_noasyncreaddir:
255 		fsopt->flags |= CEPH_MOUNT_OPT_NOASYNCREADDIR;
256 		break;
257 	case Opt_dcache:
258 		fsopt->flags |= CEPH_MOUNT_OPT_DCACHE;
259 		break;
260 	case Opt_nodcache:
261 		fsopt->flags &= ~CEPH_MOUNT_OPT_DCACHE;
262 		break;
263 	case Opt_ino32:
264 		fsopt->flags |= CEPH_MOUNT_OPT_INO32;
265 		break;
266 	case Opt_noino32:
267 		fsopt->flags &= ~CEPH_MOUNT_OPT_INO32;
268 		break;
269 	case Opt_fscache:
270 		fsopt->flags |= CEPH_MOUNT_OPT_FSCACHE;
271 		break;
272 	case Opt_nofscache:
273 		fsopt->flags &= ~CEPH_MOUNT_OPT_FSCACHE;
274 		break;
275 	case Opt_poolperm:
276 		fsopt->flags &= ~CEPH_MOUNT_OPT_NOPOOLPERM;
277 		printk ("pool perm");
278 		break;
279 	case Opt_nopoolperm:
280 		fsopt->flags |= CEPH_MOUNT_OPT_NOPOOLPERM;
281 		break;
282 #ifdef CONFIG_CEPH_FS_POSIX_ACL
283 	case Opt_acl:
284 		fsopt->sb_flags |= MS_POSIXACL;
285 		break;
286 #endif
287 	case Opt_noacl:
288 		fsopt->sb_flags &= ~MS_POSIXACL;
289 		break;
290 	default:
291 		BUG_ON(token);
292 	}
293 	return 0;
294 }
295 
296 static void destroy_mount_options(struct ceph_mount_options *args)
297 {
298 	dout("destroy_mount_options %p\n", args);
299 	kfree(args->snapdir_name);
300 	kfree(args);
301 }
302 
303 static int strcmp_null(const char *s1, const char *s2)
304 {
305 	if (!s1 && !s2)
306 		return 0;
307 	if (s1 && !s2)
308 		return -1;
309 	if (!s1 && s2)
310 		return 1;
311 	return strcmp(s1, s2);
312 }
313 
314 static int compare_mount_options(struct ceph_mount_options *new_fsopt,
315 				 struct ceph_options *new_opt,
316 				 struct ceph_fs_client *fsc)
317 {
318 	struct ceph_mount_options *fsopt1 = new_fsopt;
319 	struct ceph_mount_options *fsopt2 = fsc->mount_options;
320 	int ofs = offsetof(struct ceph_mount_options, snapdir_name);
321 	int ret;
322 
323 	ret = memcmp(fsopt1, fsopt2, ofs);
324 	if (ret)
325 		return ret;
326 
327 	ret = strcmp_null(fsopt1->snapdir_name, fsopt2->snapdir_name);
328 	if (ret)
329 		return ret;
330 
331 	return ceph_compare_options(new_opt, fsc->client);
332 }
333 
334 static int parse_mount_options(struct ceph_mount_options **pfsopt,
335 			       struct ceph_options **popt,
336 			       int flags, char *options,
337 			       const char *dev_name,
338 			       const char **path)
339 {
340 	struct ceph_mount_options *fsopt;
341 	const char *dev_name_end;
342 	int err;
343 
344 	if (!dev_name || !*dev_name)
345 		return -EINVAL;
346 
347 	fsopt = kzalloc(sizeof(*fsopt), GFP_KERNEL);
348 	if (!fsopt)
349 		return -ENOMEM;
350 
351 	dout("parse_mount_options %p, dev_name '%s'\n", fsopt, dev_name);
352 
353 	fsopt->sb_flags = flags;
354 	fsopt->flags = CEPH_MOUNT_OPT_DEFAULT;
355 
356 	fsopt->rsize = CEPH_RSIZE_DEFAULT;
357 	fsopt->rasize = CEPH_RASIZE_DEFAULT;
358 	fsopt->snapdir_name = kstrdup(CEPH_SNAPDIRNAME_DEFAULT, GFP_KERNEL);
359 	if (!fsopt->snapdir_name) {
360 		err = -ENOMEM;
361 		goto out;
362 	}
363 
364 	fsopt->caps_wanted_delay_min = CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT;
365 	fsopt->caps_wanted_delay_max = CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT;
366 	fsopt->cap_release_safety = CEPH_CAP_RELEASE_SAFETY_DEFAULT;
367 	fsopt->max_readdir = CEPH_MAX_READDIR_DEFAULT;
368 	fsopt->max_readdir_bytes = CEPH_MAX_READDIR_BYTES_DEFAULT;
369 	fsopt->congestion_kb = default_congestion_kb();
370 
371 	/*
372 	 * Distinguish the server list from the path in "dev_name".
373 	 * Internally we do not include the leading '/' in the path.
374 	 *
375 	 * "dev_name" will look like:
376 	 *     <server_spec>[,<server_spec>...]:[<path>]
377 	 * where
378 	 *     <server_spec> is <ip>[:<port>]
379 	 *     <path> is optional, but if present must begin with '/'
380 	 */
381 	dev_name_end = strchr(dev_name, '/');
382 	if (dev_name_end) {
383 		/* skip over leading '/' for path */
384 		*path = dev_name_end + 1;
385 	} else {
386 		/* path is empty */
387 		dev_name_end = dev_name + strlen(dev_name);
388 		*path = dev_name_end;
389 	}
390 	err = -EINVAL;
391 	dev_name_end--;		/* back up to ':' separator */
392 	if (dev_name_end < dev_name || *dev_name_end != ':') {
393 		pr_err("device name is missing path (no : separator in %s)\n",
394 				dev_name);
395 		goto out;
396 	}
397 	dout("device name '%.*s'\n", (int)(dev_name_end - dev_name), dev_name);
398 	dout("server path '%s'\n", *path);
399 
400 	*popt = ceph_parse_options(options, dev_name, dev_name_end,
401 				 parse_fsopt_token, (void *)fsopt);
402 	if (IS_ERR(*popt)) {
403 		err = PTR_ERR(*popt);
404 		goto out;
405 	}
406 
407 	/* success */
408 	*pfsopt = fsopt;
409 	return 0;
410 
411 out:
412 	destroy_mount_options(fsopt);
413 	return err;
414 }
415 
416 /**
417  * ceph_show_options - Show mount options in /proc/mounts
418  * @m: seq_file to write to
419  * @root: root of that (sub)tree
420  */
421 static int ceph_show_options(struct seq_file *m, struct dentry *root)
422 {
423 	struct ceph_fs_client *fsc = ceph_sb_to_client(root->d_sb);
424 	struct ceph_mount_options *fsopt = fsc->mount_options;
425 	size_t pos;
426 	int ret;
427 
428 	/* a comma between MNT/MS and client options */
429 	seq_putc(m, ',');
430 	pos = m->count;
431 
432 	ret = ceph_print_client_options(m, fsc->client);
433 	if (ret)
434 		return ret;
435 
436 	/* retract our comma if no client options */
437 	if (m->count == pos)
438 		m->count--;
439 
440 	if (fsopt->flags & CEPH_MOUNT_OPT_DIRSTAT)
441 		seq_puts(m, ",dirstat");
442 	if ((fsopt->flags & CEPH_MOUNT_OPT_RBYTES) == 0)
443 		seq_puts(m, ",norbytes");
444 	if (fsopt->flags & CEPH_MOUNT_OPT_NOASYNCREADDIR)
445 		seq_puts(m, ",noasyncreaddir");
446 	if ((fsopt->flags & CEPH_MOUNT_OPT_DCACHE) == 0)
447 		seq_puts(m, ",nodcache");
448 	if (fsopt->flags & CEPH_MOUNT_OPT_FSCACHE)
449 		seq_puts(m, ",fsc");
450 	if (fsopt->flags & CEPH_MOUNT_OPT_NOPOOLPERM)
451 		seq_puts(m, ",nopoolperm");
452 
453 #ifdef CONFIG_CEPH_FS_POSIX_ACL
454 	if (fsopt->sb_flags & MS_POSIXACL)
455 		seq_puts(m, ",acl");
456 	else
457 		seq_puts(m, ",noacl");
458 #endif
459 
460 	if (fsopt->wsize)
461 		seq_printf(m, ",wsize=%d", fsopt->wsize);
462 	if (fsopt->rsize != CEPH_RSIZE_DEFAULT)
463 		seq_printf(m, ",rsize=%d", fsopt->rsize);
464 	if (fsopt->rasize != CEPH_RASIZE_DEFAULT)
465 		seq_printf(m, ",rasize=%d", fsopt->rasize);
466 	if (fsopt->congestion_kb != default_congestion_kb())
467 		seq_printf(m, ",write_congestion_kb=%d", fsopt->congestion_kb);
468 	if (fsopt->caps_wanted_delay_min != CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT)
469 		seq_printf(m, ",caps_wanted_delay_min=%d",
470 			 fsopt->caps_wanted_delay_min);
471 	if (fsopt->caps_wanted_delay_max != CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT)
472 		seq_printf(m, ",caps_wanted_delay_max=%d",
473 			   fsopt->caps_wanted_delay_max);
474 	if (fsopt->cap_release_safety != CEPH_CAP_RELEASE_SAFETY_DEFAULT)
475 		seq_printf(m, ",cap_release_safety=%d",
476 			   fsopt->cap_release_safety);
477 	if (fsopt->max_readdir != CEPH_MAX_READDIR_DEFAULT)
478 		seq_printf(m, ",readdir_max_entries=%d", fsopt->max_readdir);
479 	if (fsopt->max_readdir_bytes != CEPH_MAX_READDIR_BYTES_DEFAULT)
480 		seq_printf(m, ",readdir_max_bytes=%d", fsopt->max_readdir_bytes);
481 	if (strcmp(fsopt->snapdir_name, CEPH_SNAPDIRNAME_DEFAULT))
482 		seq_show_option(m, "snapdirname", fsopt->snapdir_name);
483 
484 	return 0;
485 }
486 
487 /*
488  * handle any mon messages the standard library doesn't understand.
489  * return error if we don't either.
490  */
491 static int extra_mon_dispatch(struct ceph_client *client, struct ceph_msg *msg)
492 {
493 	struct ceph_fs_client *fsc = client->private;
494 	int type = le16_to_cpu(msg->hdr.type);
495 
496 	switch (type) {
497 	case CEPH_MSG_MDS_MAP:
498 		ceph_mdsc_handle_map(fsc->mdsc, msg);
499 		return 0;
500 
501 	default:
502 		return -1;
503 	}
504 }
505 
506 /*
507  * create a new fs client
508  */
509 static struct ceph_fs_client *create_fs_client(struct ceph_mount_options *fsopt,
510 					struct ceph_options *opt)
511 {
512 	struct ceph_fs_client *fsc;
513 	const u64 supported_features =
514 		CEPH_FEATURE_FLOCK |
515 		CEPH_FEATURE_DIRLAYOUTHASH |
516 		CEPH_FEATURE_MDS_INLINE_DATA;
517 	const u64 required_features = 0;
518 	int page_count;
519 	size_t size;
520 	int err = -ENOMEM;
521 
522 	fsc = kzalloc(sizeof(*fsc), GFP_KERNEL);
523 	if (!fsc)
524 		return ERR_PTR(-ENOMEM);
525 
526 	fsc->client = ceph_create_client(opt, fsc, supported_features,
527 					 required_features);
528 	if (IS_ERR(fsc->client)) {
529 		err = PTR_ERR(fsc->client);
530 		goto fail;
531 	}
532 	fsc->client->extra_mon_dispatch = extra_mon_dispatch;
533 	fsc->client->monc.want_mdsmap = 1;
534 
535 	fsc->mount_options = fsopt;
536 
537 	fsc->sb = NULL;
538 	fsc->mount_state = CEPH_MOUNT_MOUNTING;
539 
540 	atomic_long_set(&fsc->writeback_count, 0);
541 
542 	err = bdi_init(&fsc->backing_dev_info);
543 	if (err < 0)
544 		goto fail_client;
545 
546 	err = -ENOMEM;
547 	/*
548 	 * The number of concurrent works can be high but they don't need
549 	 * to be processed in parallel, limit concurrency.
550 	 */
551 	fsc->wb_wq = alloc_workqueue("ceph-writeback", 0, 1);
552 	if (fsc->wb_wq == NULL)
553 		goto fail_bdi;
554 	fsc->pg_inv_wq = alloc_workqueue("ceph-pg-invalid", 0, 1);
555 	if (fsc->pg_inv_wq == NULL)
556 		goto fail_wb_wq;
557 	fsc->trunc_wq = alloc_workqueue("ceph-trunc", 0, 1);
558 	if (fsc->trunc_wq == NULL)
559 		goto fail_pg_inv_wq;
560 
561 	/* set up mempools */
562 	err = -ENOMEM;
563 	page_count = fsc->mount_options->wsize >> PAGE_CACHE_SHIFT;
564 	size = sizeof (struct page *) * (page_count ? page_count : 1);
565 	fsc->wb_pagevec_pool = mempool_create_kmalloc_pool(10, size);
566 	if (!fsc->wb_pagevec_pool)
567 		goto fail_trunc_wq;
568 
569 	/* setup fscache */
570 	if ((fsopt->flags & CEPH_MOUNT_OPT_FSCACHE) &&
571 	    (ceph_fscache_register_fs(fsc) != 0))
572 		goto fail_fscache;
573 
574 	/* caps */
575 	fsc->min_caps = fsopt->max_readdir;
576 
577 	return fsc;
578 
579 fail_fscache:
580 	ceph_fscache_unregister_fs(fsc);
581 fail_trunc_wq:
582 	destroy_workqueue(fsc->trunc_wq);
583 fail_pg_inv_wq:
584 	destroy_workqueue(fsc->pg_inv_wq);
585 fail_wb_wq:
586 	destroy_workqueue(fsc->wb_wq);
587 fail_bdi:
588 	bdi_destroy(&fsc->backing_dev_info);
589 fail_client:
590 	ceph_destroy_client(fsc->client);
591 fail:
592 	kfree(fsc);
593 	return ERR_PTR(err);
594 }
595 
596 static void destroy_fs_client(struct ceph_fs_client *fsc)
597 {
598 	dout("destroy_fs_client %p\n", fsc);
599 
600 	ceph_fscache_unregister_fs(fsc);
601 
602 	destroy_workqueue(fsc->wb_wq);
603 	destroy_workqueue(fsc->pg_inv_wq);
604 	destroy_workqueue(fsc->trunc_wq);
605 
606 	bdi_destroy(&fsc->backing_dev_info);
607 
608 	mempool_destroy(fsc->wb_pagevec_pool);
609 
610 	destroy_mount_options(fsc->mount_options);
611 
612 	ceph_fs_debugfs_cleanup(fsc);
613 
614 	ceph_destroy_client(fsc->client);
615 
616 	kfree(fsc);
617 	dout("destroy_fs_client %p done\n", fsc);
618 }
619 
620 /*
621  * caches
622  */
623 struct kmem_cache *ceph_inode_cachep;
624 struct kmem_cache *ceph_cap_cachep;
625 struct kmem_cache *ceph_cap_flush_cachep;
626 struct kmem_cache *ceph_dentry_cachep;
627 struct kmem_cache *ceph_file_cachep;
628 
629 static void ceph_inode_init_once(void *foo)
630 {
631 	struct ceph_inode_info *ci = foo;
632 	inode_init_once(&ci->vfs_inode);
633 }
634 
635 static int __init init_caches(void)
636 {
637 	int error = -ENOMEM;
638 
639 	ceph_inode_cachep = kmem_cache_create("ceph_inode_info",
640 				      sizeof(struct ceph_inode_info),
641 				      __alignof__(struct ceph_inode_info),
642 				      SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
643 				      SLAB_ACCOUNT, ceph_inode_init_once);
644 	if (ceph_inode_cachep == NULL)
645 		return -ENOMEM;
646 
647 	ceph_cap_cachep = KMEM_CACHE(ceph_cap,
648 				     SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
649 	if (ceph_cap_cachep == NULL)
650 		goto bad_cap;
651 	ceph_cap_flush_cachep = KMEM_CACHE(ceph_cap_flush,
652 					   SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
653 	if (ceph_cap_flush_cachep == NULL)
654 		goto bad_cap_flush;
655 
656 	ceph_dentry_cachep = KMEM_CACHE(ceph_dentry_info,
657 					SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
658 	if (ceph_dentry_cachep == NULL)
659 		goto bad_dentry;
660 
661 	ceph_file_cachep = KMEM_CACHE(ceph_file_info,
662 				      SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
663 	if (ceph_file_cachep == NULL)
664 		goto bad_file;
665 
666 	if ((error = ceph_fscache_register()))
667 		goto bad_file;
668 
669 	return 0;
670 bad_file:
671 	kmem_cache_destroy(ceph_dentry_cachep);
672 bad_dentry:
673 	kmem_cache_destroy(ceph_cap_flush_cachep);
674 bad_cap_flush:
675 	kmem_cache_destroy(ceph_cap_cachep);
676 bad_cap:
677 	kmem_cache_destroy(ceph_inode_cachep);
678 	return error;
679 }
680 
681 static void destroy_caches(void)
682 {
683 	/*
684 	 * Make sure all delayed rcu free inodes are flushed before we
685 	 * destroy cache.
686 	 */
687 	rcu_barrier();
688 
689 	kmem_cache_destroy(ceph_inode_cachep);
690 	kmem_cache_destroy(ceph_cap_cachep);
691 	kmem_cache_destroy(ceph_cap_flush_cachep);
692 	kmem_cache_destroy(ceph_dentry_cachep);
693 	kmem_cache_destroy(ceph_file_cachep);
694 
695 	ceph_fscache_unregister();
696 }
697 
698 
699 /*
700  * ceph_umount_begin - initiate forced umount.  Tear down down the
701  * mount, skipping steps that may hang while waiting for server(s).
702  */
703 static void ceph_umount_begin(struct super_block *sb)
704 {
705 	struct ceph_fs_client *fsc = ceph_sb_to_client(sb);
706 
707 	dout("ceph_umount_begin - starting forced umount\n");
708 	if (!fsc)
709 		return;
710 	fsc->mount_state = CEPH_MOUNT_SHUTDOWN;
711 	ceph_mdsc_force_umount(fsc->mdsc);
712 	return;
713 }
714 
715 static const struct super_operations ceph_super_ops = {
716 	.alloc_inode	= ceph_alloc_inode,
717 	.destroy_inode	= ceph_destroy_inode,
718 	.write_inode    = ceph_write_inode,
719 	.drop_inode	= ceph_drop_inode,
720 	.sync_fs        = ceph_sync_fs,
721 	.put_super	= ceph_put_super,
722 	.show_options   = ceph_show_options,
723 	.statfs		= ceph_statfs,
724 	.umount_begin   = ceph_umount_begin,
725 };
726 
727 /*
728  * Bootstrap mount by opening the root directory.  Note the mount
729  * @started time from caller, and time out if this takes too long.
730  */
731 static struct dentry *open_root_dentry(struct ceph_fs_client *fsc,
732 				       const char *path,
733 				       unsigned long started)
734 {
735 	struct ceph_mds_client *mdsc = fsc->mdsc;
736 	struct ceph_mds_request *req = NULL;
737 	int err;
738 	struct dentry *root;
739 
740 	/* open dir */
741 	dout("open_root_inode opening '%s'\n", path);
742 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_GETATTR, USE_ANY_MDS);
743 	if (IS_ERR(req))
744 		return ERR_CAST(req);
745 	req->r_path1 = kstrdup(path, GFP_NOFS);
746 	if (!req->r_path1) {
747 		root = ERR_PTR(-ENOMEM);
748 		goto out;
749 	}
750 
751 	req->r_ino1.ino = CEPH_INO_ROOT;
752 	req->r_ino1.snap = CEPH_NOSNAP;
753 	req->r_started = started;
754 	req->r_timeout = fsc->client->options->mount_timeout;
755 	req->r_args.getattr.mask = cpu_to_le32(CEPH_STAT_CAP_INODE);
756 	req->r_num_caps = 2;
757 	err = ceph_mdsc_do_request(mdsc, NULL, req);
758 	if (err == 0) {
759 		struct inode *inode = req->r_target_inode;
760 		req->r_target_inode = NULL;
761 		dout("open_root_inode success\n");
762 		if (ceph_ino(inode) == CEPH_INO_ROOT &&
763 		    fsc->sb->s_root == NULL) {
764 			root = d_make_root(inode);
765 			if (!root) {
766 				root = ERR_PTR(-ENOMEM);
767 				goto out;
768 			}
769 		} else {
770 			root = d_obtain_root(inode);
771 		}
772 		ceph_init_dentry(root);
773 		dout("open_root_inode success, root dentry is %p\n", root);
774 	} else {
775 		root = ERR_PTR(err);
776 	}
777 out:
778 	ceph_mdsc_put_request(req);
779 	return root;
780 }
781 
782 
783 
784 
785 /*
786  * mount: join the ceph cluster, and open root directory.
787  */
788 static struct dentry *ceph_real_mount(struct ceph_fs_client *fsc,
789 		      const char *path)
790 {
791 	int err;
792 	unsigned long started = jiffies;  /* note the start time */
793 	struct dentry *root;
794 	int first = 0;   /* first vfsmount for this super_block */
795 
796 	dout("mount start\n");
797 	mutex_lock(&fsc->client->mount_mutex);
798 
799 	err = __ceph_open_session(fsc->client, started);
800 	if (err < 0)
801 		goto out;
802 
803 	dout("mount opening root\n");
804 	root = open_root_dentry(fsc, "", started);
805 	if (IS_ERR(root)) {
806 		err = PTR_ERR(root);
807 		goto out;
808 	}
809 	if (fsc->sb->s_root) {
810 		dput(root);
811 	} else {
812 		fsc->sb->s_root = root;
813 		first = 1;
814 
815 		err = ceph_fs_debugfs_init(fsc);
816 		if (err < 0)
817 			goto fail;
818 	}
819 
820 	if (path[0] == 0) {
821 		dget(root);
822 	} else {
823 		dout("mount opening base mountpoint\n");
824 		root = open_root_dentry(fsc, path, started);
825 		if (IS_ERR(root)) {
826 			err = PTR_ERR(root);
827 			goto fail;
828 		}
829 	}
830 
831 	fsc->mount_state = CEPH_MOUNT_MOUNTED;
832 	dout("mount success\n");
833 	mutex_unlock(&fsc->client->mount_mutex);
834 	return root;
835 
836 out:
837 	mutex_unlock(&fsc->client->mount_mutex);
838 	return ERR_PTR(err);
839 
840 fail:
841 	if (first) {
842 		dput(fsc->sb->s_root);
843 		fsc->sb->s_root = NULL;
844 	}
845 	goto out;
846 }
847 
848 static int ceph_set_super(struct super_block *s, void *data)
849 {
850 	struct ceph_fs_client *fsc = data;
851 	int ret;
852 
853 	dout("set_super %p data %p\n", s, data);
854 
855 	s->s_flags = fsc->mount_options->sb_flags;
856 	s->s_maxbytes = 1ULL << 40;  /* temp value until we get mdsmap */
857 
858 	s->s_xattr = ceph_xattr_handlers;
859 	s->s_fs_info = fsc;
860 	fsc->sb = s;
861 
862 	s->s_op = &ceph_super_ops;
863 	s->s_export_op = &ceph_export_ops;
864 
865 	s->s_time_gran = 1000;  /* 1000 ns == 1 us */
866 
867 	ret = set_anon_super(s, NULL);  /* what is that second arg for? */
868 	if (ret != 0)
869 		goto fail;
870 
871 	return ret;
872 
873 fail:
874 	s->s_fs_info = NULL;
875 	fsc->sb = NULL;
876 	return ret;
877 }
878 
879 /*
880  * share superblock if same fs AND options
881  */
882 static int ceph_compare_super(struct super_block *sb, void *data)
883 {
884 	struct ceph_fs_client *new = data;
885 	struct ceph_mount_options *fsopt = new->mount_options;
886 	struct ceph_options *opt = new->client->options;
887 	struct ceph_fs_client *other = ceph_sb_to_client(sb);
888 
889 	dout("ceph_compare_super %p\n", sb);
890 
891 	if (compare_mount_options(fsopt, opt, other)) {
892 		dout("monitor(s)/mount options don't match\n");
893 		return 0;
894 	}
895 	if ((opt->flags & CEPH_OPT_FSID) &&
896 	    ceph_fsid_compare(&opt->fsid, &other->client->fsid)) {
897 		dout("fsid doesn't match\n");
898 		return 0;
899 	}
900 	if (fsopt->sb_flags != other->mount_options->sb_flags) {
901 		dout("flags differ\n");
902 		return 0;
903 	}
904 	return 1;
905 }
906 
907 /*
908  * construct our own bdi so we can control readahead, etc.
909  */
910 static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0);
911 
912 static int ceph_register_bdi(struct super_block *sb,
913 			     struct ceph_fs_client *fsc)
914 {
915 	int err;
916 
917 	/* set ra_pages based on rasize mount option? */
918 	if (fsc->mount_options->rasize >= PAGE_CACHE_SIZE)
919 		fsc->backing_dev_info.ra_pages =
920 			(fsc->mount_options->rasize + PAGE_CACHE_SIZE - 1)
921 			>> PAGE_SHIFT;
922 	else
923 		fsc->backing_dev_info.ra_pages =
924 			VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE;
925 
926 	err = bdi_register(&fsc->backing_dev_info, NULL, "ceph-%ld",
927 			   atomic_long_inc_return(&bdi_seq));
928 	if (!err)
929 		sb->s_bdi = &fsc->backing_dev_info;
930 	return err;
931 }
932 
933 static struct dentry *ceph_mount(struct file_system_type *fs_type,
934 		       int flags, const char *dev_name, void *data)
935 {
936 	struct super_block *sb;
937 	struct ceph_fs_client *fsc;
938 	struct dentry *res;
939 	int err;
940 	int (*compare_super)(struct super_block *, void *) = ceph_compare_super;
941 	const char *path = NULL;
942 	struct ceph_mount_options *fsopt = NULL;
943 	struct ceph_options *opt = NULL;
944 
945 	dout("ceph_mount\n");
946 
947 #ifdef CONFIG_CEPH_FS_POSIX_ACL
948 	flags |= MS_POSIXACL;
949 #endif
950 	err = parse_mount_options(&fsopt, &opt, flags, data, dev_name, &path);
951 	if (err < 0) {
952 		res = ERR_PTR(err);
953 		goto out_final;
954 	}
955 
956 	/* create client (which we may/may not use) */
957 	fsc = create_fs_client(fsopt, opt);
958 	if (IS_ERR(fsc)) {
959 		res = ERR_CAST(fsc);
960 		destroy_mount_options(fsopt);
961 		ceph_destroy_options(opt);
962 		goto out_final;
963 	}
964 
965 	err = ceph_mdsc_init(fsc);
966 	if (err < 0) {
967 		res = ERR_PTR(err);
968 		goto out;
969 	}
970 
971 	if (ceph_test_opt(fsc->client, NOSHARE))
972 		compare_super = NULL;
973 	sb = sget(fs_type, compare_super, ceph_set_super, flags, fsc);
974 	if (IS_ERR(sb)) {
975 		res = ERR_CAST(sb);
976 		goto out;
977 	}
978 
979 	if (ceph_sb_to_client(sb) != fsc) {
980 		ceph_mdsc_destroy(fsc);
981 		destroy_fs_client(fsc);
982 		fsc = ceph_sb_to_client(sb);
983 		dout("get_sb got existing client %p\n", fsc);
984 	} else {
985 		dout("get_sb using new client %p\n", fsc);
986 		err = ceph_register_bdi(sb, fsc);
987 		if (err < 0) {
988 			res = ERR_PTR(err);
989 			goto out_splat;
990 		}
991 	}
992 
993 	res = ceph_real_mount(fsc, path);
994 	if (IS_ERR(res))
995 		goto out_splat;
996 	dout("root %p inode %p ino %llx.%llx\n", res,
997 	     d_inode(res), ceph_vinop(d_inode(res)));
998 	return res;
999 
1000 out_splat:
1001 	ceph_mdsc_close_sessions(fsc->mdsc);
1002 	deactivate_locked_super(sb);
1003 	goto out_final;
1004 
1005 out:
1006 	ceph_mdsc_destroy(fsc);
1007 	destroy_fs_client(fsc);
1008 out_final:
1009 	dout("ceph_mount fail %ld\n", PTR_ERR(res));
1010 	return res;
1011 }
1012 
1013 static void ceph_kill_sb(struct super_block *s)
1014 {
1015 	struct ceph_fs_client *fsc = ceph_sb_to_client(s);
1016 	dev_t dev = s->s_dev;
1017 
1018 	dout("kill_sb %p\n", s);
1019 
1020 	ceph_mdsc_pre_umount(fsc->mdsc);
1021 	generic_shutdown_super(s);
1022 	ceph_mdsc_destroy(fsc);
1023 
1024 	destroy_fs_client(fsc);
1025 	free_anon_bdev(dev);
1026 }
1027 
1028 static struct file_system_type ceph_fs_type = {
1029 	.owner		= THIS_MODULE,
1030 	.name		= "ceph",
1031 	.mount		= ceph_mount,
1032 	.kill_sb	= ceph_kill_sb,
1033 	.fs_flags	= FS_RENAME_DOES_D_MOVE,
1034 };
1035 MODULE_ALIAS_FS("ceph");
1036 
1037 static int __init init_ceph(void)
1038 {
1039 	int ret = init_caches();
1040 	if (ret)
1041 		goto out;
1042 
1043 	ceph_flock_init();
1044 	ceph_xattr_init();
1045 	ret = ceph_snap_init();
1046 	if (ret)
1047 		goto out_xattr;
1048 	ret = register_filesystem(&ceph_fs_type);
1049 	if (ret)
1050 		goto out_snap;
1051 
1052 	pr_info("loaded (mds proto %d)\n", CEPH_MDSC_PROTOCOL);
1053 
1054 	return 0;
1055 
1056 out_snap:
1057 	ceph_snap_exit();
1058 out_xattr:
1059 	ceph_xattr_exit();
1060 	destroy_caches();
1061 out:
1062 	return ret;
1063 }
1064 
1065 static void __exit exit_ceph(void)
1066 {
1067 	dout("exit_ceph\n");
1068 	unregister_filesystem(&ceph_fs_type);
1069 	ceph_snap_exit();
1070 	ceph_xattr_exit();
1071 	destroy_caches();
1072 }
1073 
1074 module_init(init_ceph);
1075 module_exit(exit_ceph);
1076 
1077 MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
1078 MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
1079 MODULE_AUTHOR("Patience Warnick <patience@newdream.net>");
1080 MODULE_DESCRIPTION("Ceph filesystem for Linux");
1081 MODULE_LICENSE("GPL");
1082