xref: /openbmc/linux/fs/ceph/super.c (revision 3e30a927)
1 // SPDX-License-Identifier: GPL-2.0-only
2 
3 #include <linux/ceph/ceph_debug.h>
4 
5 #include <linux/backing-dev.h>
6 #include <linux/ctype.h>
7 #include <linux/fs.h>
8 #include <linux/inet.h>
9 #include <linux/in6.h>
10 #include <linux/module.h>
11 #include <linux/mount.h>
12 #include <linux/fs_context.h>
13 #include <linux/fs_parser.h>
14 #include <linux/sched.h>
15 #include <linux/seq_file.h>
16 #include <linux/slab.h>
17 #include <linux/statfs.h>
18 #include <linux/string.h>
19 
20 #include "super.h"
21 #include "mds_client.h"
22 #include "cache.h"
23 
24 #include <linux/ceph/ceph_features.h>
25 #include <linux/ceph/decode.h>
26 #include <linux/ceph/mon_client.h>
27 #include <linux/ceph/auth.h>
28 #include <linux/ceph/debugfs.h>
29 
30 /*
31  * Ceph superblock operations
32  *
33  * Handle the basics of mounting, unmounting.
34  */
35 
36 /*
37  * super ops
38  */
39 static void ceph_put_super(struct super_block *s)
40 {
41 	struct ceph_fs_client *fsc = ceph_sb_to_client(s);
42 
43 	dout("put_super\n");
44 	ceph_mdsc_close_sessions(fsc->mdsc);
45 }
46 
47 static int ceph_statfs(struct dentry *dentry, struct kstatfs *buf)
48 {
49 	struct ceph_fs_client *fsc = ceph_inode_to_client(d_inode(dentry));
50 	struct ceph_mon_client *monc = &fsc->client->monc;
51 	struct ceph_statfs st;
52 	u64 fsid;
53 	int err;
54 	u64 data_pool;
55 
56 	if (fsc->mdsc->mdsmap->m_num_data_pg_pools == 1) {
57 		data_pool = fsc->mdsc->mdsmap->m_data_pg_pools[0];
58 	} else {
59 		data_pool = CEPH_NOPOOL;
60 	}
61 
62 	dout("statfs\n");
63 	err = ceph_monc_do_statfs(monc, data_pool, &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 	 * NOTE: for the time being, we make bsize == frsize to humor
75 	 * not-yet-ancient versions of glibc that are broken.
76 	 * Someday, we will probably want to report a real block
77 	 * size...  whatever that may mean for a network file system!
78 	 */
79 	buf->f_bsize = 1 << CEPH_BLOCK_SHIFT;
80 	buf->f_frsize = 1 << CEPH_BLOCK_SHIFT;
81 
82 	/*
83 	 * By default use root quota for stats; fallback to overall filesystem
84 	 * usage if using 'noquotadf' mount option or if the root dir doesn't
85 	 * have max_bytes quota set.
86 	 */
87 	if (ceph_test_mount_opt(fsc, NOQUOTADF) ||
88 	    !ceph_quota_update_statfs(fsc, buf)) {
89 		buf->f_blocks = le64_to_cpu(st.kb) >> (CEPH_BLOCK_SHIFT-10);
90 		buf->f_bfree = le64_to_cpu(st.kb_avail) >> (CEPH_BLOCK_SHIFT-10);
91 		buf->f_bavail = le64_to_cpu(st.kb_avail) >> (CEPH_BLOCK_SHIFT-10);
92 	}
93 
94 	buf->f_files = le64_to_cpu(st.num_objects);
95 	buf->f_ffree = -1;
96 	buf->f_namelen = NAME_MAX;
97 
98 	/* Must convert the fsid, for consistent values across arches */
99 	mutex_lock(&monc->mutex);
100 	fsid = le64_to_cpu(*(__le64 *)(&monc->monmap->fsid)) ^
101 	       le64_to_cpu(*((__le64 *)&monc->monmap->fsid + 1));
102 	mutex_unlock(&monc->mutex);
103 
104 	buf->f_fsid.val[0] = fsid & 0xffffffff;
105 	buf->f_fsid.val[1] = fsid >> 32;
106 
107 	return 0;
108 }
109 
110 static int ceph_sync_fs(struct super_block *sb, int wait)
111 {
112 	struct ceph_fs_client *fsc = ceph_sb_to_client(sb);
113 
114 	if (!wait) {
115 		dout("sync_fs (non-blocking)\n");
116 		ceph_flush_dirty_caps(fsc->mdsc);
117 		dout("sync_fs (non-blocking) done\n");
118 		return 0;
119 	}
120 
121 	dout("sync_fs (blocking)\n");
122 	ceph_osdc_sync(&fsc->client->osdc);
123 	ceph_mdsc_sync(fsc->mdsc);
124 	dout("sync_fs (blocking) done\n");
125 	return 0;
126 }
127 
128 /*
129  * mount options
130  */
131 enum {
132 	Opt_wsize,
133 	Opt_rsize,
134 	Opt_rasize,
135 	Opt_caps_wanted_delay_min,
136 	Opt_caps_wanted_delay_max,
137 	Opt_caps_max,
138 	Opt_readdir_max_entries,
139 	Opt_readdir_max_bytes,
140 	Opt_congestion_kb,
141 	/* int args above */
142 	Opt_snapdirname,
143 	Opt_mds_namespace,
144 	Opt_recover_session,
145 	Opt_source,
146 	/* string args above */
147 	Opt_dirstat,
148 	Opt_rbytes,
149 	Opt_asyncreaddir,
150 	Opt_dcache,
151 	Opt_ino32,
152 	Opt_fscache,
153 	Opt_poolperm,
154 	Opt_require_active_mds,
155 	Opt_acl,
156 	Opt_quotadf,
157 	Opt_copyfrom,
158 };
159 
160 enum ceph_recover_session_mode {
161 	ceph_recover_session_no,
162 	ceph_recover_session_clean
163 };
164 
165 static const struct constant_table ceph_param_recover[] = {
166 	{ "no",		ceph_recover_session_no },
167 	{ "clean",	ceph_recover_session_clean },
168 	{}
169 };
170 
171 static const struct fs_parameter_spec ceph_mount_parameters[] = {
172 	fsparam_flag_no ("acl",				Opt_acl),
173 	fsparam_flag_no ("asyncreaddir",		Opt_asyncreaddir),
174 	fsparam_s32	("caps_max",			Opt_caps_max),
175 	fsparam_u32	("caps_wanted_delay_max",	Opt_caps_wanted_delay_max),
176 	fsparam_u32	("caps_wanted_delay_min",	Opt_caps_wanted_delay_min),
177 	fsparam_u32	("write_congestion_kb",		Opt_congestion_kb),
178 	fsparam_flag_no ("copyfrom",			Opt_copyfrom),
179 	fsparam_flag_no ("dcache",			Opt_dcache),
180 	fsparam_flag_no ("dirstat",			Opt_dirstat),
181 	fsparam_flag_no	("fsc",				Opt_fscache), // fsc|nofsc
182 	fsparam_string	("fsc",				Opt_fscache), // fsc=...
183 	fsparam_flag_no ("ino32",			Opt_ino32),
184 	fsparam_string	("mds_namespace",		Opt_mds_namespace),
185 	fsparam_flag_no ("poolperm",			Opt_poolperm),
186 	fsparam_flag_no ("quotadf",			Opt_quotadf),
187 	fsparam_u32	("rasize",			Opt_rasize),
188 	fsparam_flag_no ("rbytes",			Opt_rbytes),
189 	fsparam_u32	("readdir_max_bytes",		Opt_readdir_max_bytes),
190 	fsparam_u32	("readdir_max_entries",		Opt_readdir_max_entries),
191 	fsparam_enum	("recover_session",		Opt_recover_session, ceph_param_recover),
192 	fsparam_flag_no ("require_active_mds",		Opt_require_active_mds),
193 	fsparam_u32	("rsize",			Opt_rsize),
194 	fsparam_string	("snapdirname",			Opt_snapdirname),
195 	fsparam_string	("source",			Opt_source),
196 	fsparam_u32	("wsize",			Opt_wsize),
197 	{}
198 };
199 
200 struct ceph_parse_opts_ctx {
201 	struct ceph_options		*copts;
202 	struct ceph_mount_options	*opts;
203 };
204 
205 /*
206  * Parse the source parameter.  Distinguish the server list from the path.
207  *
208  * The source will look like:
209  *     <server_spec>[,<server_spec>...]:[<path>]
210  * where
211  *     <server_spec> is <ip>[:<port>]
212  *     <path> is optional, but if present must begin with '/'
213  */
214 static int ceph_parse_source(struct fs_parameter *param, struct fs_context *fc)
215 {
216 	struct ceph_parse_opts_ctx *pctx = fc->fs_private;
217 	struct ceph_mount_options *fsopt = pctx->opts;
218 	char *dev_name = param->string, *dev_name_end;
219 	int ret;
220 
221 	dout("%s '%s'\n", __func__, dev_name);
222 	if (!dev_name || !*dev_name)
223 		return invalfc(fc, "Empty source");
224 
225 	dev_name_end = strchr(dev_name, '/');
226 	if (dev_name_end) {
227 		kfree(fsopt->server_path);
228 
229 		/*
230 		 * The server_path will include the whole chars from userland
231 		 * including the leading '/'.
232 		 */
233 		fsopt->server_path = kstrdup(dev_name_end, GFP_KERNEL);
234 		if (!fsopt->server_path)
235 			return -ENOMEM;
236 	} else {
237 		dev_name_end = dev_name + strlen(dev_name);
238 	}
239 
240 	dev_name_end--;		/* back up to ':' separator */
241 	if (dev_name_end < dev_name || *dev_name_end != ':')
242 		return invalfc(fc, "No path or : separator in source");
243 
244 	dout("device name '%.*s'\n", (int)(dev_name_end - dev_name), dev_name);
245 	if (fsopt->server_path)
246 		dout("server path '%s'\n", fsopt->server_path);
247 
248 	ret = ceph_parse_mon_ips(param->string, dev_name_end - dev_name,
249 				 pctx->copts, fc->log.log);
250 	if (ret)
251 		return ret;
252 
253 	fc->source = param->string;
254 	param->string = NULL;
255 	return 0;
256 }
257 
258 static int ceph_parse_mount_param(struct fs_context *fc,
259 				  struct fs_parameter *param)
260 {
261 	struct ceph_parse_opts_ctx *pctx = fc->fs_private;
262 	struct ceph_mount_options *fsopt = pctx->opts;
263 	struct fs_parse_result result;
264 	unsigned int mode;
265 	int token, ret;
266 
267 	ret = ceph_parse_param(param, pctx->copts, fc->log.log);
268 	if (ret != -ENOPARAM)
269 		return ret;
270 
271 	token = fs_parse(fc, ceph_mount_parameters, param, &result);
272 	dout("%s fs_parse '%s' token %d\n", __func__, param->key, token);
273 	if (token < 0)
274 		return token;
275 
276 	switch (token) {
277 	case Opt_snapdirname:
278 		kfree(fsopt->snapdir_name);
279 		fsopt->snapdir_name = param->string;
280 		param->string = NULL;
281 		break;
282 	case Opt_mds_namespace:
283 		kfree(fsopt->mds_namespace);
284 		fsopt->mds_namespace = param->string;
285 		param->string = NULL;
286 		break;
287 	case Opt_recover_session:
288 		mode = result.uint_32;
289 		if (mode == ceph_recover_session_no)
290 			fsopt->flags &= ~CEPH_MOUNT_OPT_CLEANRECOVER;
291 		else if (mode == ceph_recover_session_clean)
292 			fsopt->flags |= CEPH_MOUNT_OPT_CLEANRECOVER;
293 		else
294 			BUG();
295 		break;
296 	case Opt_source:
297 		if (fc->source)
298 			return invalfc(fc, "Multiple sources specified");
299 		return ceph_parse_source(param, fc);
300 	case Opt_wsize:
301 		if (result.uint_32 < PAGE_SIZE ||
302 		    result.uint_32 > CEPH_MAX_WRITE_SIZE)
303 			goto out_of_range;
304 		fsopt->wsize = ALIGN(result.uint_32, PAGE_SIZE);
305 		break;
306 	case Opt_rsize:
307 		if (result.uint_32 < PAGE_SIZE ||
308 		    result.uint_32 > CEPH_MAX_READ_SIZE)
309 			goto out_of_range;
310 		fsopt->rsize = ALIGN(result.uint_32, PAGE_SIZE);
311 		break;
312 	case Opt_rasize:
313 		fsopt->rasize = ALIGN(result.uint_32, PAGE_SIZE);
314 		break;
315 	case Opt_caps_wanted_delay_min:
316 		if (result.uint_32 < 1)
317 			goto out_of_range;
318 		fsopt->caps_wanted_delay_min = result.uint_32;
319 		break;
320 	case Opt_caps_wanted_delay_max:
321 		if (result.uint_32 < 1)
322 			goto out_of_range;
323 		fsopt->caps_wanted_delay_max = result.uint_32;
324 		break;
325 	case Opt_caps_max:
326 		if (result.int_32 < 0)
327 			goto out_of_range;
328 		fsopt->caps_max = result.int_32;
329 		break;
330 	case Opt_readdir_max_entries:
331 		if (result.uint_32 < 1)
332 			goto out_of_range;
333 		fsopt->max_readdir = result.uint_32;
334 		break;
335 	case Opt_readdir_max_bytes:
336 		if (result.uint_32 < PAGE_SIZE && result.uint_32 != 0)
337 			goto out_of_range;
338 		fsopt->max_readdir_bytes = result.uint_32;
339 		break;
340 	case Opt_congestion_kb:
341 		if (result.uint_32 < 1024) /* at least 1M */
342 			goto out_of_range;
343 		fsopt->congestion_kb = result.uint_32;
344 		break;
345 	case Opt_dirstat:
346 		if (!result.negated)
347 			fsopt->flags |= CEPH_MOUNT_OPT_DIRSTAT;
348 		else
349 			fsopt->flags &= ~CEPH_MOUNT_OPT_DIRSTAT;
350 		break;
351 	case Opt_rbytes:
352 		if (!result.negated)
353 			fsopt->flags |= CEPH_MOUNT_OPT_RBYTES;
354 		else
355 			fsopt->flags &= ~CEPH_MOUNT_OPT_RBYTES;
356 		break;
357 	case Opt_asyncreaddir:
358 		if (!result.negated)
359 			fsopt->flags &= ~CEPH_MOUNT_OPT_NOASYNCREADDIR;
360 		else
361 			fsopt->flags |= CEPH_MOUNT_OPT_NOASYNCREADDIR;
362 		break;
363 	case Opt_dcache:
364 		if (!result.negated)
365 			fsopt->flags |= CEPH_MOUNT_OPT_DCACHE;
366 		else
367 			fsopt->flags &= ~CEPH_MOUNT_OPT_DCACHE;
368 		break;
369 	case Opt_ino32:
370 		if (!result.negated)
371 			fsopt->flags |= CEPH_MOUNT_OPT_INO32;
372 		else
373 			fsopt->flags &= ~CEPH_MOUNT_OPT_INO32;
374 		break;
375 
376 	case Opt_fscache:
377 #ifdef CONFIG_CEPH_FSCACHE
378 		kfree(fsopt->fscache_uniq);
379 		fsopt->fscache_uniq = NULL;
380 		if (result.negated) {
381 			fsopt->flags &= ~CEPH_MOUNT_OPT_FSCACHE;
382 		} else {
383 			fsopt->flags |= CEPH_MOUNT_OPT_FSCACHE;
384 			fsopt->fscache_uniq = param->string;
385 			param->string = NULL;
386 		}
387 		break;
388 #else
389 		return invalfc(fc, "fscache support is disabled");
390 #endif
391 	case Opt_poolperm:
392 		if (!result.negated)
393 			fsopt->flags &= ~CEPH_MOUNT_OPT_NOPOOLPERM;
394 		else
395 			fsopt->flags |= CEPH_MOUNT_OPT_NOPOOLPERM;
396 		break;
397 	case Opt_require_active_mds:
398 		if (!result.negated)
399 			fsopt->flags &= ~CEPH_MOUNT_OPT_MOUNTWAIT;
400 		else
401 			fsopt->flags |= CEPH_MOUNT_OPT_MOUNTWAIT;
402 		break;
403 	case Opt_quotadf:
404 		if (!result.negated)
405 			fsopt->flags &= ~CEPH_MOUNT_OPT_NOQUOTADF;
406 		else
407 			fsopt->flags |= CEPH_MOUNT_OPT_NOQUOTADF;
408 		break;
409 	case Opt_copyfrom:
410 		if (!result.negated)
411 			fsopt->flags &= ~CEPH_MOUNT_OPT_NOCOPYFROM;
412 		else
413 			fsopt->flags |= CEPH_MOUNT_OPT_NOCOPYFROM;
414 		break;
415 	case Opt_acl:
416 		if (!result.negated) {
417 #ifdef CONFIG_CEPH_FS_POSIX_ACL
418 			fc->sb_flags |= SB_POSIXACL;
419 #else
420 			return invalfc(fc, "POSIX ACL support is disabled");
421 #endif
422 		} else {
423 			fc->sb_flags &= ~SB_POSIXACL;
424 		}
425 		break;
426 	default:
427 		BUG();
428 	}
429 	return 0;
430 
431 out_of_range:
432 	return invalfc(fc, "%s out of range", param->key);
433 }
434 
435 static void destroy_mount_options(struct ceph_mount_options *args)
436 {
437 	dout("destroy_mount_options %p\n", args);
438 	if (!args)
439 		return;
440 
441 	kfree(args->snapdir_name);
442 	kfree(args->mds_namespace);
443 	kfree(args->server_path);
444 	kfree(args->fscache_uniq);
445 	kfree(args);
446 }
447 
448 static int strcmp_null(const char *s1, const char *s2)
449 {
450 	if (!s1 && !s2)
451 		return 0;
452 	if (s1 && !s2)
453 		return -1;
454 	if (!s1 && s2)
455 		return 1;
456 	return strcmp(s1, s2);
457 }
458 
459 /**
460  * path_remove_extra_slash - Remove the extra slashes in the server path
461  * @server_path: the server path and could be NULL
462  *
463  * Return NULL if the path is NULL or only consists of "/", or a string
464  * without any extra slashes including the leading slash(es) and the
465  * slash(es) at the end of the server path, such as:
466  * "//dir1////dir2///" --> "dir1/dir2"
467  */
468 static char *path_remove_extra_slash(const char *server_path)
469 {
470 	const char *path = server_path;
471 	const char *cur, *end;
472 	char *buf, *p;
473 	int len;
474 
475 	/* if the server path is omitted */
476 	if (!path)
477 		return NULL;
478 
479 	/* remove all the leading slashes */
480 	while (*path == '/')
481 		path++;
482 
483 	/* if the server path only consists of slashes */
484 	if (*path == '\0')
485 		return NULL;
486 
487 	len = strlen(path);
488 
489 	buf = kmalloc(len + 1, GFP_KERNEL);
490 	if (!buf)
491 		return ERR_PTR(-ENOMEM);
492 
493 	end = path + len;
494 	p = buf;
495 	do {
496 		cur = strchr(path, '/');
497 		if (!cur)
498 			cur = end;
499 
500 		len = cur - path;
501 
502 		/* including one '/' */
503 		if (cur != end)
504 			len += 1;
505 
506 		memcpy(p, path, len);
507 		p += len;
508 
509 		while (cur <= end && *cur == '/')
510 			cur++;
511 		path = cur;
512 	} while (path < end);
513 
514 	*p = '\0';
515 
516 	/*
517 	 * remove the last slash if there has and just to make sure that
518 	 * we will get something like "dir1/dir2"
519 	 */
520 	if (*(--p) == '/')
521 		*p = '\0';
522 
523 	return buf;
524 }
525 
526 static int compare_mount_options(struct ceph_mount_options *new_fsopt,
527 				 struct ceph_options *new_opt,
528 				 struct ceph_fs_client *fsc)
529 {
530 	struct ceph_mount_options *fsopt1 = new_fsopt;
531 	struct ceph_mount_options *fsopt2 = fsc->mount_options;
532 	int ofs = offsetof(struct ceph_mount_options, snapdir_name);
533 	char *p1, *p2;
534 	int ret;
535 
536 	ret = memcmp(fsopt1, fsopt2, ofs);
537 	if (ret)
538 		return ret;
539 
540 	ret = strcmp_null(fsopt1->snapdir_name, fsopt2->snapdir_name);
541 	if (ret)
542 		return ret;
543 	ret = strcmp_null(fsopt1->mds_namespace, fsopt2->mds_namespace);
544 	if (ret)
545 		return ret;
546 
547 	p1 = path_remove_extra_slash(fsopt1->server_path);
548 	if (IS_ERR(p1))
549 		return PTR_ERR(p1);
550 	p2 = path_remove_extra_slash(fsopt2->server_path);
551 	if (IS_ERR(p2)) {
552 		kfree(p1);
553 		return PTR_ERR(p2);
554 	}
555 	ret = strcmp_null(p1, p2);
556 	kfree(p1);
557 	kfree(p2);
558 	if (ret)
559 		return ret;
560 
561 	ret = strcmp_null(fsopt1->fscache_uniq, fsopt2->fscache_uniq);
562 	if (ret)
563 		return ret;
564 
565 	return ceph_compare_options(new_opt, fsc->client);
566 }
567 
568 /**
569  * ceph_show_options - Show mount options in /proc/mounts
570  * @m: seq_file to write to
571  * @root: root of that (sub)tree
572  */
573 static int ceph_show_options(struct seq_file *m, struct dentry *root)
574 {
575 	struct ceph_fs_client *fsc = ceph_sb_to_client(root->d_sb);
576 	struct ceph_mount_options *fsopt = fsc->mount_options;
577 	size_t pos;
578 	int ret;
579 
580 	/* a comma between MNT/MS and client options */
581 	seq_putc(m, ',');
582 	pos = m->count;
583 
584 	ret = ceph_print_client_options(m, fsc->client, false);
585 	if (ret)
586 		return ret;
587 
588 	/* retract our comma if no client options */
589 	if (m->count == pos)
590 		m->count--;
591 
592 	if (fsopt->flags & CEPH_MOUNT_OPT_DIRSTAT)
593 		seq_puts(m, ",dirstat");
594 	if ((fsopt->flags & CEPH_MOUNT_OPT_RBYTES))
595 		seq_puts(m, ",rbytes");
596 	if (fsopt->flags & CEPH_MOUNT_OPT_NOASYNCREADDIR)
597 		seq_puts(m, ",noasyncreaddir");
598 	if ((fsopt->flags & CEPH_MOUNT_OPT_DCACHE) == 0)
599 		seq_puts(m, ",nodcache");
600 	if (fsopt->flags & CEPH_MOUNT_OPT_INO32)
601 		seq_puts(m, ",ino32");
602 	if (fsopt->flags & CEPH_MOUNT_OPT_FSCACHE) {
603 		seq_show_option(m, "fsc", fsopt->fscache_uniq);
604 	}
605 	if (fsopt->flags & CEPH_MOUNT_OPT_NOPOOLPERM)
606 		seq_puts(m, ",nopoolperm");
607 	if (fsopt->flags & CEPH_MOUNT_OPT_NOQUOTADF)
608 		seq_puts(m, ",noquotadf");
609 
610 #ifdef CONFIG_CEPH_FS_POSIX_ACL
611 	if (root->d_sb->s_flags & SB_POSIXACL)
612 		seq_puts(m, ",acl");
613 	else
614 		seq_puts(m, ",noacl");
615 #endif
616 
617 	if ((fsopt->flags & CEPH_MOUNT_OPT_NOCOPYFROM) == 0)
618 		seq_puts(m, ",copyfrom");
619 
620 	if (fsopt->mds_namespace)
621 		seq_show_option(m, "mds_namespace", fsopt->mds_namespace);
622 
623 	if (fsopt->flags & CEPH_MOUNT_OPT_CLEANRECOVER)
624 		seq_show_option(m, "recover_session", "clean");
625 
626 	if (fsopt->wsize != CEPH_MAX_WRITE_SIZE)
627 		seq_printf(m, ",wsize=%u", fsopt->wsize);
628 	if (fsopt->rsize != CEPH_MAX_READ_SIZE)
629 		seq_printf(m, ",rsize=%u", fsopt->rsize);
630 	if (fsopt->rasize != CEPH_RASIZE_DEFAULT)
631 		seq_printf(m, ",rasize=%u", fsopt->rasize);
632 	if (fsopt->congestion_kb != default_congestion_kb())
633 		seq_printf(m, ",write_congestion_kb=%u", fsopt->congestion_kb);
634 	if (fsopt->caps_max)
635 		seq_printf(m, ",caps_max=%d", fsopt->caps_max);
636 	if (fsopt->caps_wanted_delay_min != CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT)
637 		seq_printf(m, ",caps_wanted_delay_min=%u",
638 			 fsopt->caps_wanted_delay_min);
639 	if (fsopt->caps_wanted_delay_max != CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT)
640 		seq_printf(m, ",caps_wanted_delay_max=%u",
641 			   fsopt->caps_wanted_delay_max);
642 	if (fsopt->max_readdir != CEPH_MAX_READDIR_DEFAULT)
643 		seq_printf(m, ",readdir_max_entries=%u", fsopt->max_readdir);
644 	if (fsopt->max_readdir_bytes != CEPH_MAX_READDIR_BYTES_DEFAULT)
645 		seq_printf(m, ",readdir_max_bytes=%u", fsopt->max_readdir_bytes);
646 	if (strcmp(fsopt->snapdir_name, CEPH_SNAPDIRNAME_DEFAULT))
647 		seq_show_option(m, "snapdirname", fsopt->snapdir_name);
648 
649 	return 0;
650 }
651 
652 /*
653  * handle any mon messages the standard library doesn't understand.
654  * return error if we don't either.
655  */
656 static int extra_mon_dispatch(struct ceph_client *client, struct ceph_msg *msg)
657 {
658 	struct ceph_fs_client *fsc = client->private;
659 	int type = le16_to_cpu(msg->hdr.type);
660 
661 	switch (type) {
662 	case CEPH_MSG_MDS_MAP:
663 		ceph_mdsc_handle_mdsmap(fsc->mdsc, msg);
664 		return 0;
665 	case CEPH_MSG_FS_MAP_USER:
666 		ceph_mdsc_handle_fsmap(fsc->mdsc, msg);
667 		return 0;
668 	default:
669 		return -1;
670 	}
671 }
672 
673 /*
674  * create a new fs client
675  *
676  * Success or not, this function consumes @fsopt and @opt.
677  */
678 static struct ceph_fs_client *create_fs_client(struct ceph_mount_options *fsopt,
679 					struct ceph_options *opt)
680 {
681 	struct ceph_fs_client *fsc;
682 	int page_count;
683 	size_t size;
684 	int err;
685 
686 	fsc = kzalloc(sizeof(*fsc), GFP_KERNEL);
687 	if (!fsc) {
688 		err = -ENOMEM;
689 		goto fail;
690 	}
691 
692 	fsc->client = ceph_create_client(opt, fsc);
693 	if (IS_ERR(fsc->client)) {
694 		err = PTR_ERR(fsc->client);
695 		goto fail;
696 	}
697 	opt = NULL; /* fsc->client now owns this */
698 
699 	fsc->client->extra_mon_dispatch = extra_mon_dispatch;
700 	ceph_set_opt(fsc->client, ABORT_ON_FULL);
701 
702 	if (!fsopt->mds_namespace) {
703 		ceph_monc_want_map(&fsc->client->monc, CEPH_SUB_MDSMAP,
704 				   0, true);
705 	} else {
706 		ceph_monc_want_map(&fsc->client->monc, CEPH_SUB_FSMAP,
707 				   0, false);
708 	}
709 
710 	fsc->mount_options = fsopt;
711 
712 	fsc->sb = NULL;
713 	fsc->mount_state = CEPH_MOUNT_MOUNTING;
714 	fsc->filp_gen = 1;
715 	fsc->have_copy_from2 = true;
716 
717 	atomic_long_set(&fsc->writeback_count, 0);
718 
719 	err = -ENOMEM;
720 	/*
721 	 * The number of concurrent works can be high but they don't need
722 	 * to be processed in parallel, limit concurrency.
723 	 */
724 	fsc->inode_wq = alloc_workqueue("ceph-inode", WQ_UNBOUND, 0);
725 	if (!fsc->inode_wq)
726 		goto fail_client;
727 	fsc->cap_wq = alloc_workqueue("ceph-cap", 0, 1);
728 	if (!fsc->cap_wq)
729 		goto fail_inode_wq;
730 
731 	/* set up mempools */
732 	err = -ENOMEM;
733 	page_count = fsc->mount_options->wsize >> PAGE_SHIFT;
734 	size = sizeof (struct page *) * (page_count ? page_count : 1);
735 	fsc->wb_pagevec_pool = mempool_create_kmalloc_pool(10, size);
736 	if (!fsc->wb_pagevec_pool)
737 		goto fail_cap_wq;
738 
739 	return fsc;
740 
741 fail_cap_wq:
742 	destroy_workqueue(fsc->cap_wq);
743 fail_inode_wq:
744 	destroy_workqueue(fsc->inode_wq);
745 fail_client:
746 	ceph_destroy_client(fsc->client);
747 fail:
748 	kfree(fsc);
749 	if (opt)
750 		ceph_destroy_options(opt);
751 	destroy_mount_options(fsopt);
752 	return ERR_PTR(err);
753 }
754 
755 static void flush_fs_workqueues(struct ceph_fs_client *fsc)
756 {
757 	flush_workqueue(fsc->inode_wq);
758 	flush_workqueue(fsc->cap_wq);
759 }
760 
761 static void destroy_fs_client(struct ceph_fs_client *fsc)
762 {
763 	dout("destroy_fs_client %p\n", fsc);
764 
765 	ceph_mdsc_destroy(fsc);
766 	destroy_workqueue(fsc->inode_wq);
767 	destroy_workqueue(fsc->cap_wq);
768 
769 	mempool_destroy(fsc->wb_pagevec_pool);
770 
771 	destroy_mount_options(fsc->mount_options);
772 
773 	ceph_destroy_client(fsc->client);
774 
775 	kfree(fsc);
776 	dout("destroy_fs_client %p done\n", fsc);
777 }
778 
779 /*
780  * caches
781  */
782 struct kmem_cache *ceph_inode_cachep;
783 struct kmem_cache *ceph_cap_cachep;
784 struct kmem_cache *ceph_cap_flush_cachep;
785 struct kmem_cache *ceph_dentry_cachep;
786 struct kmem_cache *ceph_file_cachep;
787 struct kmem_cache *ceph_dir_file_cachep;
788 
789 static void ceph_inode_init_once(void *foo)
790 {
791 	struct ceph_inode_info *ci = foo;
792 	inode_init_once(&ci->vfs_inode);
793 }
794 
795 static int __init init_caches(void)
796 {
797 	int error = -ENOMEM;
798 
799 	ceph_inode_cachep = kmem_cache_create("ceph_inode_info",
800 				      sizeof(struct ceph_inode_info),
801 				      __alignof__(struct ceph_inode_info),
802 				      SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
803 				      SLAB_ACCOUNT, ceph_inode_init_once);
804 	if (!ceph_inode_cachep)
805 		return -ENOMEM;
806 
807 	ceph_cap_cachep = KMEM_CACHE(ceph_cap, SLAB_MEM_SPREAD);
808 	if (!ceph_cap_cachep)
809 		goto bad_cap;
810 	ceph_cap_flush_cachep = KMEM_CACHE(ceph_cap_flush,
811 					   SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
812 	if (!ceph_cap_flush_cachep)
813 		goto bad_cap_flush;
814 
815 	ceph_dentry_cachep = KMEM_CACHE(ceph_dentry_info,
816 					SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
817 	if (!ceph_dentry_cachep)
818 		goto bad_dentry;
819 
820 	ceph_file_cachep = KMEM_CACHE(ceph_file_info, SLAB_MEM_SPREAD);
821 	if (!ceph_file_cachep)
822 		goto bad_file;
823 
824 	ceph_dir_file_cachep = KMEM_CACHE(ceph_dir_file_info, SLAB_MEM_SPREAD);
825 	if (!ceph_dir_file_cachep)
826 		goto bad_dir_file;
827 
828 	error = ceph_fscache_register();
829 	if (error)
830 		goto bad_fscache;
831 
832 	return 0;
833 
834 bad_fscache:
835 	kmem_cache_destroy(ceph_dir_file_cachep);
836 bad_dir_file:
837 	kmem_cache_destroy(ceph_file_cachep);
838 bad_file:
839 	kmem_cache_destroy(ceph_dentry_cachep);
840 bad_dentry:
841 	kmem_cache_destroy(ceph_cap_flush_cachep);
842 bad_cap_flush:
843 	kmem_cache_destroy(ceph_cap_cachep);
844 bad_cap:
845 	kmem_cache_destroy(ceph_inode_cachep);
846 	return error;
847 }
848 
849 static void destroy_caches(void)
850 {
851 	/*
852 	 * Make sure all delayed rcu free inodes are flushed before we
853 	 * destroy cache.
854 	 */
855 	rcu_barrier();
856 
857 	kmem_cache_destroy(ceph_inode_cachep);
858 	kmem_cache_destroy(ceph_cap_cachep);
859 	kmem_cache_destroy(ceph_cap_flush_cachep);
860 	kmem_cache_destroy(ceph_dentry_cachep);
861 	kmem_cache_destroy(ceph_file_cachep);
862 	kmem_cache_destroy(ceph_dir_file_cachep);
863 
864 	ceph_fscache_unregister();
865 }
866 
867 /*
868  * ceph_umount_begin - initiate forced umount.  Tear down down the
869  * mount, skipping steps that may hang while waiting for server(s).
870  */
871 static void ceph_umount_begin(struct super_block *sb)
872 {
873 	struct ceph_fs_client *fsc = ceph_sb_to_client(sb);
874 
875 	dout("ceph_umount_begin - starting forced umount\n");
876 	if (!fsc)
877 		return;
878 	fsc->mount_state = CEPH_MOUNT_SHUTDOWN;
879 	ceph_osdc_abort_requests(&fsc->client->osdc, -EIO);
880 	ceph_mdsc_force_umount(fsc->mdsc);
881 	fsc->filp_gen++; // invalidate open files
882 }
883 
884 static const struct super_operations ceph_super_ops = {
885 	.alloc_inode	= ceph_alloc_inode,
886 	.free_inode	= ceph_free_inode,
887 	.write_inode    = ceph_write_inode,
888 	.drop_inode	= generic_delete_inode,
889 	.evict_inode	= ceph_evict_inode,
890 	.sync_fs        = ceph_sync_fs,
891 	.put_super	= ceph_put_super,
892 	.show_options   = ceph_show_options,
893 	.statfs		= ceph_statfs,
894 	.umount_begin   = ceph_umount_begin,
895 };
896 
897 /*
898  * Bootstrap mount by opening the root directory.  Note the mount
899  * @started time from caller, and time out if this takes too long.
900  */
901 static struct dentry *open_root_dentry(struct ceph_fs_client *fsc,
902 				       const char *path,
903 				       unsigned long started)
904 {
905 	struct ceph_mds_client *mdsc = fsc->mdsc;
906 	struct ceph_mds_request *req = NULL;
907 	int err;
908 	struct dentry *root;
909 
910 	/* open dir */
911 	dout("open_root_inode opening '%s'\n", path);
912 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_GETATTR, USE_ANY_MDS);
913 	if (IS_ERR(req))
914 		return ERR_CAST(req);
915 	req->r_path1 = kstrdup(path, GFP_NOFS);
916 	if (!req->r_path1) {
917 		root = ERR_PTR(-ENOMEM);
918 		goto out;
919 	}
920 
921 	req->r_ino1.ino = CEPH_INO_ROOT;
922 	req->r_ino1.snap = CEPH_NOSNAP;
923 	req->r_started = started;
924 	req->r_timeout = fsc->client->options->mount_timeout;
925 	req->r_args.getattr.mask = cpu_to_le32(CEPH_STAT_CAP_INODE);
926 	req->r_num_caps = 2;
927 	err = ceph_mdsc_do_request(mdsc, NULL, req);
928 	if (err == 0) {
929 		struct inode *inode = req->r_target_inode;
930 		req->r_target_inode = NULL;
931 		dout("open_root_inode success\n");
932 		root = d_make_root(inode);
933 		if (!root) {
934 			root = ERR_PTR(-ENOMEM);
935 			goto out;
936 		}
937 		dout("open_root_inode success, root dentry is %p\n", root);
938 	} else {
939 		root = ERR_PTR(err);
940 	}
941 out:
942 	ceph_mdsc_put_request(req);
943 	return root;
944 }
945 
946 /*
947  * mount: join the ceph cluster, and open root directory.
948  */
949 static struct dentry *ceph_real_mount(struct ceph_fs_client *fsc,
950 				      struct fs_context *fc)
951 {
952 	int err;
953 	unsigned long started = jiffies;  /* note the start time */
954 	struct dentry *root;
955 
956 	dout("mount start %p\n", fsc);
957 	mutex_lock(&fsc->client->mount_mutex);
958 
959 	if (!fsc->sb->s_root) {
960 		const char *path, *p;
961 		err = __ceph_open_session(fsc->client, started);
962 		if (err < 0)
963 			goto out;
964 
965 		/* setup fscache */
966 		if (fsc->mount_options->flags & CEPH_MOUNT_OPT_FSCACHE) {
967 			err = ceph_fscache_register_fs(fsc, fc);
968 			if (err < 0)
969 				goto out;
970 		}
971 
972 		p = path_remove_extra_slash(fsc->mount_options->server_path);
973 		if (IS_ERR(p)) {
974 			err = PTR_ERR(p);
975 			goto out;
976 		}
977 		/* if the server path is omitted or just consists of '/' */
978 		if (!p)
979 			path = "";
980 		else
981 			path = p;
982 		dout("mount opening path '%s'\n", path);
983 
984 		ceph_fs_debugfs_init(fsc);
985 
986 		root = open_root_dentry(fsc, path, started);
987 		kfree(p);
988 		if (IS_ERR(root)) {
989 			err = PTR_ERR(root);
990 			goto out;
991 		}
992 		fsc->sb->s_root = dget(root);
993 	} else {
994 		root = dget(fsc->sb->s_root);
995 	}
996 
997 	fsc->mount_state = CEPH_MOUNT_MOUNTED;
998 	dout("mount success\n");
999 	mutex_unlock(&fsc->client->mount_mutex);
1000 	return root;
1001 
1002 out:
1003 	mutex_unlock(&fsc->client->mount_mutex);
1004 	return ERR_PTR(err);
1005 }
1006 
1007 static int ceph_set_super(struct super_block *s, struct fs_context *fc)
1008 {
1009 	struct ceph_fs_client *fsc = s->s_fs_info;
1010 	int ret;
1011 
1012 	dout("set_super %p\n", s);
1013 
1014 	s->s_maxbytes = MAX_LFS_FILESIZE;
1015 
1016 	s->s_xattr = ceph_xattr_handlers;
1017 	fsc->sb = s;
1018 	fsc->max_file_size = 1ULL << 40; /* temp value until we get mdsmap */
1019 
1020 	s->s_op = &ceph_super_ops;
1021 	s->s_d_op = &ceph_dentry_ops;
1022 	s->s_export_op = &ceph_export_ops;
1023 
1024 	s->s_time_gran = 1;
1025 	s->s_time_min = 0;
1026 	s->s_time_max = U32_MAX;
1027 
1028 	ret = set_anon_super_fc(s, fc);
1029 	if (ret != 0)
1030 		fsc->sb = NULL;
1031 	return ret;
1032 }
1033 
1034 /*
1035  * share superblock if same fs AND options
1036  */
1037 static int ceph_compare_super(struct super_block *sb, struct fs_context *fc)
1038 {
1039 	struct ceph_fs_client *new = fc->s_fs_info;
1040 	struct ceph_mount_options *fsopt = new->mount_options;
1041 	struct ceph_options *opt = new->client->options;
1042 	struct ceph_fs_client *other = ceph_sb_to_client(sb);
1043 
1044 	dout("ceph_compare_super %p\n", sb);
1045 
1046 	if (compare_mount_options(fsopt, opt, other)) {
1047 		dout("monitor(s)/mount options don't match\n");
1048 		return 0;
1049 	}
1050 	if ((opt->flags & CEPH_OPT_FSID) &&
1051 	    ceph_fsid_compare(&opt->fsid, &other->client->fsid)) {
1052 		dout("fsid doesn't match\n");
1053 		return 0;
1054 	}
1055 	if (fc->sb_flags != (sb->s_flags & ~SB_BORN)) {
1056 		dout("flags differ\n");
1057 		return 0;
1058 	}
1059 	return 1;
1060 }
1061 
1062 /*
1063  * construct our own bdi so we can control readahead, etc.
1064  */
1065 static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0);
1066 
1067 static int ceph_setup_bdi(struct super_block *sb, struct ceph_fs_client *fsc)
1068 {
1069 	int err;
1070 
1071 	err = super_setup_bdi_name(sb, "ceph-%ld",
1072 				   atomic_long_inc_return(&bdi_seq));
1073 	if (err)
1074 		return err;
1075 
1076 	/* set ra_pages based on rasize mount option? */
1077 	sb->s_bdi->ra_pages = fsc->mount_options->rasize >> PAGE_SHIFT;
1078 
1079 	/* set io_pages based on max osd read size */
1080 	sb->s_bdi->io_pages = fsc->mount_options->rsize >> PAGE_SHIFT;
1081 
1082 	return 0;
1083 }
1084 
1085 static int ceph_get_tree(struct fs_context *fc)
1086 {
1087 	struct ceph_parse_opts_ctx *pctx = fc->fs_private;
1088 	struct super_block *sb;
1089 	struct ceph_fs_client *fsc;
1090 	struct dentry *res;
1091 	int (*compare_super)(struct super_block *, struct fs_context *) =
1092 		ceph_compare_super;
1093 	int err;
1094 
1095 	dout("ceph_get_tree\n");
1096 
1097 	if (!fc->source)
1098 		return invalfc(fc, "No source");
1099 
1100 #ifdef CONFIG_CEPH_FS_POSIX_ACL
1101 	fc->sb_flags |= SB_POSIXACL;
1102 #endif
1103 
1104 	/* create client (which we may/may not use) */
1105 	fsc = create_fs_client(pctx->opts, pctx->copts);
1106 	pctx->opts = NULL;
1107 	pctx->copts = NULL;
1108 	if (IS_ERR(fsc)) {
1109 		err = PTR_ERR(fsc);
1110 		goto out_final;
1111 	}
1112 
1113 	err = ceph_mdsc_init(fsc);
1114 	if (err < 0)
1115 		goto out;
1116 
1117 	if (ceph_test_opt(fsc->client, NOSHARE))
1118 		compare_super = NULL;
1119 
1120 	fc->s_fs_info = fsc;
1121 	sb = sget_fc(fc, compare_super, ceph_set_super);
1122 	fc->s_fs_info = NULL;
1123 	if (IS_ERR(sb)) {
1124 		err = PTR_ERR(sb);
1125 		goto out;
1126 	}
1127 
1128 	if (ceph_sb_to_client(sb) != fsc) {
1129 		destroy_fs_client(fsc);
1130 		fsc = ceph_sb_to_client(sb);
1131 		dout("get_sb got existing client %p\n", fsc);
1132 	} else {
1133 		dout("get_sb using new client %p\n", fsc);
1134 		err = ceph_setup_bdi(sb, fsc);
1135 		if (err < 0)
1136 			goto out_splat;
1137 	}
1138 
1139 	res = ceph_real_mount(fsc, fc);
1140 	if (IS_ERR(res)) {
1141 		err = PTR_ERR(res);
1142 		goto out_splat;
1143 	}
1144 	dout("root %p inode %p ino %llx.%llx\n", res,
1145 	     d_inode(res), ceph_vinop(d_inode(res)));
1146 	fc->root = fsc->sb->s_root;
1147 	return 0;
1148 
1149 out_splat:
1150 	if (!ceph_mdsmap_is_cluster_available(fsc->mdsc->mdsmap)) {
1151 		pr_info("No mds server is up or the cluster is laggy\n");
1152 		err = -EHOSTUNREACH;
1153 	}
1154 
1155 	ceph_mdsc_close_sessions(fsc->mdsc);
1156 	deactivate_locked_super(sb);
1157 	goto out_final;
1158 
1159 out:
1160 	destroy_fs_client(fsc);
1161 out_final:
1162 	dout("ceph_get_tree fail %d\n", err);
1163 	return err;
1164 }
1165 
1166 static void ceph_free_fc(struct fs_context *fc)
1167 {
1168 	struct ceph_parse_opts_ctx *pctx = fc->fs_private;
1169 
1170 	if (pctx) {
1171 		destroy_mount_options(pctx->opts);
1172 		ceph_destroy_options(pctx->copts);
1173 		kfree(pctx);
1174 	}
1175 }
1176 
1177 static int ceph_reconfigure_fc(struct fs_context *fc)
1178 {
1179 	sync_filesystem(fc->root->d_sb);
1180 	return 0;
1181 }
1182 
1183 static const struct fs_context_operations ceph_context_ops = {
1184 	.free		= ceph_free_fc,
1185 	.parse_param	= ceph_parse_mount_param,
1186 	.get_tree	= ceph_get_tree,
1187 	.reconfigure	= ceph_reconfigure_fc,
1188 };
1189 
1190 /*
1191  * Set up the filesystem mount context.
1192  */
1193 static int ceph_init_fs_context(struct fs_context *fc)
1194 {
1195 	struct ceph_parse_opts_ctx *pctx;
1196 	struct ceph_mount_options *fsopt;
1197 
1198 	pctx = kzalloc(sizeof(*pctx), GFP_KERNEL);
1199 	if (!pctx)
1200 		return -ENOMEM;
1201 
1202 	pctx->copts = ceph_alloc_options();
1203 	if (!pctx->copts)
1204 		goto nomem;
1205 
1206 	pctx->opts = kzalloc(sizeof(*pctx->opts), GFP_KERNEL);
1207 	if (!pctx->opts)
1208 		goto nomem;
1209 
1210 	fsopt = pctx->opts;
1211 	fsopt->flags = CEPH_MOUNT_OPT_DEFAULT;
1212 
1213 	fsopt->wsize = CEPH_MAX_WRITE_SIZE;
1214 	fsopt->rsize = CEPH_MAX_READ_SIZE;
1215 	fsopt->rasize = CEPH_RASIZE_DEFAULT;
1216 	fsopt->snapdir_name = kstrdup(CEPH_SNAPDIRNAME_DEFAULT, GFP_KERNEL);
1217 	if (!fsopt->snapdir_name)
1218 		goto nomem;
1219 
1220 	fsopt->caps_wanted_delay_min = CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT;
1221 	fsopt->caps_wanted_delay_max = CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT;
1222 	fsopt->max_readdir = CEPH_MAX_READDIR_DEFAULT;
1223 	fsopt->max_readdir_bytes = CEPH_MAX_READDIR_BYTES_DEFAULT;
1224 	fsopt->congestion_kb = default_congestion_kb();
1225 
1226 	fc->fs_private = pctx;
1227 	fc->ops = &ceph_context_ops;
1228 	return 0;
1229 
1230 nomem:
1231 	destroy_mount_options(pctx->opts);
1232 	ceph_destroy_options(pctx->copts);
1233 	kfree(pctx);
1234 	return -ENOMEM;
1235 }
1236 
1237 static void ceph_kill_sb(struct super_block *s)
1238 {
1239 	struct ceph_fs_client *fsc = ceph_sb_to_client(s);
1240 	dev_t dev = s->s_dev;
1241 
1242 	dout("kill_sb %p\n", s);
1243 
1244 	ceph_mdsc_pre_umount(fsc->mdsc);
1245 	flush_fs_workqueues(fsc);
1246 
1247 	generic_shutdown_super(s);
1248 
1249 	fsc->client->extra_mon_dispatch = NULL;
1250 	ceph_fs_debugfs_cleanup(fsc);
1251 
1252 	ceph_fscache_unregister_fs(fsc);
1253 
1254 	destroy_fs_client(fsc);
1255 	free_anon_bdev(dev);
1256 }
1257 
1258 static struct file_system_type ceph_fs_type = {
1259 	.owner		= THIS_MODULE,
1260 	.name		= "ceph",
1261 	.init_fs_context = ceph_init_fs_context,
1262 	.kill_sb	= ceph_kill_sb,
1263 	.fs_flags	= FS_RENAME_DOES_D_MOVE,
1264 };
1265 MODULE_ALIAS_FS("ceph");
1266 
1267 int ceph_force_reconnect(struct super_block *sb)
1268 {
1269 	struct ceph_fs_client *fsc = ceph_sb_to_client(sb);
1270 	int err = 0;
1271 
1272 	ceph_umount_begin(sb);
1273 
1274 	/* Make sure all page caches get invalidated.
1275 	 * see remove_session_caps_cb() */
1276 	flush_workqueue(fsc->inode_wq);
1277 
1278 	/* In case that we were blacklisted. This also reset
1279 	 * all mon/osd connections */
1280 	ceph_reset_client_addr(fsc->client);
1281 
1282 	ceph_osdc_clear_abort_err(&fsc->client->osdc);
1283 
1284 	fsc->blacklisted = false;
1285 	fsc->mount_state = CEPH_MOUNT_MOUNTED;
1286 
1287 	if (sb->s_root) {
1288 		err = __ceph_do_getattr(d_inode(sb->s_root), NULL,
1289 					CEPH_STAT_CAP_INODE, true);
1290 	}
1291 	return err;
1292 }
1293 
1294 static int __init init_ceph(void)
1295 {
1296 	int ret = init_caches();
1297 	if (ret)
1298 		goto out;
1299 
1300 	ceph_flock_init();
1301 	ret = register_filesystem(&ceph_fs_type);
1302 	if (ret)
1303 		goto out_caches;
1304 
1305 	pr_info("loaded (mds proto %d)\n", CEPH_MDSC_PROTOCOL);
1306 
1307 	return 0;
1308 
1309 out_caches:
1310 	destroy_caches();
1311 out:
1312 	return ret;
1313 }
1314 
1315 static void __exit exit_ceph(void)
1316 {
1317 	dout("exit_ceph\n");
1318 	unregister_filesystem(&ceph_fs_type);
1319 	destroy_caches();
1320 }
1321 
1322 module_init(init_ceph);
1323 module_exit(exit_ceph);
1324 
1325 MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
1326 MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
1327 MODULE_AUTHOR("Patience Warnick <patience@newdream.net>");
1328 MODULE_DESCRIPTION("Ceph filesystem for Linux");
1329 MODULE_LICENSE("GPL");
1330