xref: /openbmc/linux/fs/ceph/super.c (revision 3b23dc52)
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_mon_client *monc = &fsc->client->monc;
49 	struct ceph_statfs st;
50 	u64 fsid;
51 	int err;
52 	u64 data_pool;
53 
54 	if (fsc->mdsc->mdsmap->m_num_data_pg_pools == 1) {
55 		data_pool = fsc->mdsc->mdsmap->m_data_pg_pools[0];
56 	} else {
57 		data_pool = CEPH_NOPOOL;
58 	}
59 
60 	dout("statfs\n");
61 	err = ceph_monc_do_statfs(monc, data_pool, &st);
62 	if (err < 0)
63 		return err;
64 
65 	/* fill in kstatfs */
66 	buf->f_type = CEPH_SUPER_MAGIC;  /* ?? */
67 
68 	/*
69 	 * express utilization in terms of large blocks to avoid
70 	 * overflow on 32-bit machines.
71 	 *
72 	 * NOTE: for the time being, we make bsize == frsize to humor
73 	 * not-yet-ancient versions of glibc that are broken.
74 	 * Someday, we will probably want to report a real block
75 	 * size...  whatever that may mean for a network file system!
76 	 */
77 	buf->f_bsize = 1 << CEPH_BLOCK_SHIFT;
78 	buf->f_frsize = 1 << CEPH_BLOCK_SHIFT;
79 
80 	/*
81 	 * By default use root quota for stats; fallback to overall filesystem
82 	 * usage if using 'noquotadf' mount option or if the root dir doesn't
83 	 * have max_bytes quota set.
84 	 */
85 	if (ceph_test_mount_opt(fsc, NOQUOTADF) ||
86 	    !ceph_quota_update_statfs(fsc, buf)) {
87 		buf->f_blocks = le64_to_cpu(st.kb) >> (CEPH_BLOCK_SHIFT-10);
88 		buf->f_bfree = le64_to_cpu(st.kb_avail) >> (CEPH_BLOCK_SHIFT-10);
89 		buf->f_bavail = le64_to_cpu(st.kb_avail) >> (CEPH_BLOCK_SHIFT-10);
90 	}
91 
92 	buf->f_files = le64_to_cpu(st.num_objects);
93 	buf->f_ffree = -1;
94 	buf->f_namelen = NAME_MAX;
95 
96 	/* Must convert the fsid, for consistent values across arches */
97 	mutex_lock(&monc->mutex);
98 	fsid = le64_to_cpu(*(__le64 *)(&monc->monmap->fsid)) ^
99 	       le64_to_cpu(*((__le64 *)&monc->monmap->fsid + 1));
100 	mutex_unlock(&monc->mutex);
101 
102 	buf->f_fsid.val[0] = fsid & 0xffffffff;
103 	buf->f_fsid.val[1] = fsid >> 32;
104 
105 	return 0;
106 }
107 
108 
109 static int ceph_sync_fs(struct super_block *sb, int wait)
110 {
111 	struct ceph_fs_client *fsc = ceph_sb_to_client(sb);
112 
113 	if (!wait) {
114 		dout("sync_fs (non-blocking)\n");
115 		ceph_flush_dirty_caps(fsc->mdsc);
116 		dout("sync_fs (non-blocking) done\n");
117 		return 0;
118 	}
119 
120 	dout("sync_fs (blocking)\n");
121 	ceph_osdc_sync(&fsc->client->osdc);
122 	ceph_mdsc_sync(fsc->mdsc);
123 	dout("sync_fs (blocking) done\n");
124 	return 0;
125 }
126 
127 /*
128  * mount options
129  */
130 enum {
131 	Opt_wsize,
132 	Opt_rsize,
133 	Opt_rasize,
134 	Opt_caps_wanted_delay_min,
135 	Opt_caps_wanted_delay_max,
136 	Opt_readdir_max_entries,
137 	Opt_readdir_max_bytes,
138 	Opt_congestion_kb,
139 	Opt_last_int,
140 	/* int args above */
141 	Opt_snapdirname,
142 	Opt_mds_namespace,
143 	Opt_fscache_uniq,
144 	Opt_last_string,
145 	/* string args above */
146 	Opt_dirstat,
147 	Opt_nodirstat,
148 	Opt_rbytes,
149 	Opt_norbytes,
150 	Opt_asyncreaddir,
151 	Opt_noasyncreaddir,
152 	Opt_dcache,
153 	Opt_nodcache,
154 	Opt_ino32,
155 	Opt_noino32,
156 	Opt_fscache,
157 	Opt_nofscache,
158 	Opt_poolperm,
159 	Opt_nopoolperm,
160 	Opt_require_active_mds,
161 	Opt_norequire_active_mds,
162 #ifdef CONFIG_CEPH_FS_POSIX_ACL
163 	Opt_acl,
164 #endif
165 	Opt_noacl,
166 	Opt_quotadf,
167 	Opt_noquotadf,
168 };
169 
170 static match_table_t fsopt_tokens = {
171 	{Opt_wsize, "wsize=%d"},
172 	{Opt_rsize, "rsize=%d"},
173 	{Opt_rasize, "rasize=%d"},
174 	{Opt_caps_wanted_delay_min, "caps_wanted_delay_min=%d"},
175 	{Opt_caps_wanted_delay_max, "caps_wanted_delay_max=%d"},
176 	{Opt_readdir_max_entries, "readdir_max_entries=%d"},
177 	{Opt_readdir_max_bytes, "readdir_max_bytes=%d"},
178 	{Opt_congestion_kb, "write_congestion_kb=%d"},
179 	/* int args above */
180 	{Opt_snapdirname, "snapdirname=%s"},
181 	{Opt_mds_namespace, "mds_namespace=%s"},
182 	{Opt_fscache_uniq, "fsc=%s"},
183 	/* string args above */
184 	{Opt_dirstat, "dirstat"},
185 	{Opt_nodirstat, "nodirstat"},
186 	{Opt_rbytes, "rbytes"},
187 	{Opt_norbytes, "norbytes"},
188 	{Opt_asyncreaddir, "asyncreaddir"},
189 	{Opt_noasyncreaddir, "noasyncreaddir"},
190 	{Opt_dcache, "dcache"},
191 	{Opt_nodcache, "nodcache"},
192 	{Opt_ino32, "ino32"},
193 	{Opt_noino32, "noino32"},
194 	{Opt_fscache, "fsc"},
195 	{Opt_nofscache, "nofsc"},
196 	{Opt_poolperm, "poolperm"},
197 	{Opt_nopoolperm, "nopoolperm"},
198 	{Opt_require_active_mds, "require_active_mds"},
199 	{Opt_norequire_active_mds, "norequire_active_mds"},
200 #ifdef CONFIG_CEPH_FS_POSIX_ACL
201 	{Opt_acl, "acl"},
202 #endif
203 	{Opt_noacl, "noacl"},
204 	{Opt_quotadf, "quotadf"},
205 	{Opt_noquotadf, "noquotadf"},
206 	{-1, NULL}
207 };
208 
209 static int parse_fsopt_token(char *c, void *private)
210 {
211 	struct ceph_mount_options *fsopt = private;
212 	substring_t argstr[MAX_OPT_ARGS];
213 	int token, intval, ret;
214 
215 	token = match_token((char *)c, fsopt_tokens, argstr);
216 	if (token < 0)
217 		return -EINVAL;
218 
219 	if (token < Opt_last_int) {
220 		ret = match_int(&argstr[0], &intval);
221 		if (ret < 0) {
222 			pr_err("bad mount option arg (not int) "
223 			       "at '%s'\n", c);
224 			return ret;
225 		}
226 		dout("got int token %d val %d\n", token, intval);
227 	} else if (token > Opt_last_int && token < Opt_last_string) {
228 		dout("got string token %d val %s\n", token,
229 		     argstr[0].from);
230 	} else {
231 		dout("got token %d\n", token);
232 	}
233 
234 	switch (token) {
235 	case Opt_snapdirname:
236 		kfree(fsopt->snapdir_name);
237 		fsopt->snapdir_name = kstrndup(argstr[0].from,
238 					       argstr[0].to-argstr[0].from,
239 					       GFP_KERNEL);
240 		if (!fsopt->snapdir_name)
241 			return -ENOMEM;
242 		break;
243 	case Opt_mds_namespace:
244 		kfree(fsopt->mds_namespace);
245 		fsopt->mds_namespace = kstrndup(argstr[0].from,
246 						argstr[0].to-argstr[0].from,
247 						GFP_KERNEL);
248 		if (!fsopt->mds_namespace)
249 			return -ENOMEM;
250 		break;
251 	case Opt_fscache_uniq:
252 		kfree(fsopt->fscache_uniq);
253 		fsopt->fscache_uniq = kstrndup(argstr[0].from,
254 					       argstr[0].to-argstr[0].from,
255 					       GFP_KERNEL);
256 		if (!fsopt->fscache_uniq)
257 			return -ENOMEM;
258 		fsopt->flags |= CEPH_MOUNT_OPT_FSCACHE;
259 		break;
260 		/* misc */
261 	case Opt_wsize:
262 		if (intval < (int)PAGE_SIZE || intval > CEPH_MAX_WRITE_SIZE)
263 			return -EINVAL;
264 		fsopt->wsize = ALIGN(intval, PAGE_SIZE);
265 		break;
266 	case Opt_rsize:
267 		if (intval < (int)PAGE_SIZE || intval > CEPH_MAX_READ_SIZE)
268 			return -EINVAL;
269 		fsopt->rsize = ALIGN(intval, PAGE_SIZE);
270 		break;
271 	case Opt_rasize:
272 		if (intval < 0)
273 			return -EINVAL;
274 		fsopt->rasize = ALIGN(intval, PAGE_SIZE);
275 		break;
276 	case Opt_caps_wanted_delay_min:
277 		if (intval < 1)
278 			return -EINVAL;
279 		fsopt->caps_wanted_delay_min = intval;
280 		break;
281 	case Opt_caps_wanted_delay_max:
282 		if (intval < 1)
283 			return -EINVAL;
284 		fsopt->caps_wanted_delay_max = intval;
285 		break;
286 	case Opt_readdir_max_entries:
287 		if (intval < 1)
288 			return -EINVAL;
289 		fsopt->max_readdir = intval;
290 		break;
291 	case Opt_readdir_max_bytes:
292 		if (intval < (int)PAGE_SIZE && intval != 0)
293 			return -EINVAL;
294 		fsopt->max_readdir_bytes = intval;
295 		break;
296 	case Opt_congestion_kb:
297 		if (intval < 1024) /* at least 1M */
298 			return -EINVAL;
299 		fsopt->congestion_kb = intval;
300 		break;
301 	case Opt_dirstat:
302 		fsopt->flags |= CEPH_MOUNT_OPT_DIRSTAT;
303 		break;
304 	case Opt_nodirstat:
305 		fsopt->flags &= ~CEPH_MOUNT_OPT_DIRSTAT;
306 		break;
307 	case Opt_rbytes:
308 		fsopt->flags |= CEPH_MOUNT_OPT_RBYTES;
309 		break;
310 	case Opt_norbytes:
311 		fsopt->flags &= ~CEPH_MOUNT_OPT_RBYTES;
312 		break;
313 	case Opt_asyncreaddir:
314 		fsopt->flags &= ~CEPH_MOUNT_OPT_NOASYNCREADDIR;
315 		break;
316 	case Opt_noasyncreaddir:
317 		fsopt->flags |= CEPH_MOUNT_OPT_NOASYNCREADDIR;
318 		break;
319 	case Opt_dcache:
320 		fsopt->flags |= CEPH_MOUNT_OPT_DCACHE;
321 		break;
322 	case Opt_nodcache:
323 		fsopt->flags &= ~CEPH_MOUNT_OPT_DCACHE;
324 		break;
325 	case Opt_ino32:
326 		fsopt->flags |= CEPH_MOUNT_OPT_INO32;
327 		break;
328 	case Opt_noino32:
329 		fsopt->flags &= ~CEPH_MOUNT_OPT_INO32;
330 		break;
331 	case Opt_fscache:
332 		fsopt->flags |= CEPH_MOUNT_OPT_FSCACHE;
333 		kfree(fsopt->fscache_uniq);
334 		fsopt->fscache_uniq = NULL;
335 		break;
336 	case Opt_nofscache:
337 		fsopt->flags &= ~CEPH_MOUNT_OPT_FSCACHE;
338 		kfree(fsopt->fscache_uniq);
339 		fsopt->fscache_uniq = NULL;
340 		break;
341 	case Opt_poolperm:
342 		fsopt->flags &= ~CEPH_MOUNT_OPT_NOPOOLPERM;
343 		break;
344 	case Opt_nopoolperm:
345 		fsopt->flags |= CEPH_MOUNT_OPT_NOPOOLPERM;
346 		break;
347 	case Opt_require_active_mds:
348 		fsopt->flags &= ~CEPH_MOUNT_OPT_MOUNTWAIT;
349 		break;
350 	case Opt_norequire_active_mds:
351 		fsopt->flags |= CEPH_MOUNT_OPT_MOUNTWAIT;
352 		break;
353 	case Opt_quotadf:
354 		fsopt->flags &= ~CEPH_MOUNT_OPT_NOQUOTADF;
355 		break;
356 	case Opt_noquotadf:
357 		fsopt->flags |= CEPH_MOUNT_OPT_NOQUOTADF;
358 		break;
359 #ifdef CONFIG_CEPH_FS_POSIX_ACL
360 	case Opt_acl:
361 		fsopt->sb_flags |= SB_POSIXACL;
362 		break;
363 #endif
364 	case Opt_noacl:
365 		fsopt->sb_flags &= ~SB_POSIXACL;
366 		break;
367 	default:
368 		BUG_ON(token);
369 	}
370 	return 0;
371 }
372 
373 static void destroy_mount_options(struct ceph_mount_options *args)
374 {
375 	dout("destroy_mount_options %p\n", args);
376 	kfree(args->snapdir_name);
377 	kfree(args->mds_namespace);
378 	kfree(args->server_path);
379 	kfree(args->fscache_uniq);
380 	kfree(args);
381 }
382 
383 static int strcmp_null(const char *s1, const char *s2)
384 {
385 	if (!s1 && !s2)
386 		return 0;
387 	if (s1 && !s2)
388 		return -1;
389 	if (!s1 && s2)
390 		return 1;
391 	return strcmp(s1, s2);
392 }
393 
394 static int compare_mount_options(struct ceph_mount_options *new_fsopt,
395 				 struct ceph_options *new_opt,
396 				 struct ceph_fs_client *fsc)
397 {
398 	struct ceph_mount_options *fsopt1 = new_fsopt;
399 	struct ceph_mount_options *fsopt2 = fsc->mount_options;
400 	int ofs = offsetof(struct ceph_mount_options, snapdir_name);
401 	int ret;
402 
403 	ret = memcmp(fsopt1, fsopt2, ofs);
404 	if (ret)
405 		return ret;
406 
407 	ret = strcmp_null(fsopt1->snapdir_name, fsopt2->snapdir_name);
408 	if (ret)
409 		return ret;
410 	ret = strcmp_null(fsopt1->mds_namespace, fsopt2->mds_namespace);
411 	if (ret)
412 		return ret;
413 	ret = strcmp_null(fsopt1->server_path, fsopt2->server_path);
414 	if (ret)
415 		return ret;
416 	ret = strcmp_null(fsopt1->fscache_uniq, fsopt2->fscache_uniq);
417 	if (ret)
418 		return ret;
419 
420 	return ceph_compare_options(new_opt, fsc->client);
421 }
422 
423 static int parse_mount_options(struct ceph_mount_options **pfsopt,
424 			       struct ceph_options **popt,
425 			       int flags, char *options,
426 			       const char *dev_name)
427 {
428 	struct ceph_mount_options *fsopt;
429 	const char *dev_name_end;
430 	int err;
431 
432 	if (!dev_name || !*dev_name)
433 		return -EINVAL;
434 
435 	fsopt = kzalloc(sizeof(*fsopt), GFP_KERNEL);
436 	if (!fsopt)
437 		return -ENOMEM;
438 
439 	dout("parse_mount_options %p, dev_name '%s'\n", fsopt, dev_name);
440 
441 	fsopt->sb_flags = flags;
442 	fsopt->flags = CEPH_MOUNT_OPT_DEFAULT;
443 
444 	fsopt->wsize = CEPH_MAX_WRITE_SIZE;
445 	fsopt->rsize = CEPH_MAX_READ_SIZE;
446 	fsopt->rasize = CEPH_RASIZE_DEFAULT;
447 	fsopt->snapdir_name = kstrdup(CEPH_SNAPDIRNAME_DEFAULT, GFP_KERNEL);
448 	if (!fsopt->snapdir_name) {
449 		err = -ENOMEM;
450 		goto out;
451 	}
452 
453 	fsopt->caps_wanted_delay_min = CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT;
454 	fsopt->caps_wanted_delay_max = CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT;
455 	fsopt->max_readdir = CEPH_MAX_READDIR_DEFAULT;
456 	fsopt->max_readdir_bytes = CEPH_MAX_READDIR_BYTES_DEFAULT;
457 	fsopt->congestion_kb = default_congestion_kb();
458 
459 	/*
460 	 * Distinguish the server list from the path in "dev_name".
461 	 * Internally we do not include the leading '/' in the path.
462 	 *
463 	 * "dev_name" will look like:
464 	 *     <server_spec>[,<server_spec>...]:[<path>]
465 	 * where
466 	 *     <server_spec> is <ip>[:<port>]
467 	 *     <path> is optional, but if present must begin with '/'
468 	 */
469 	dev_name_end = strchr(dev_name, '/');
470 	if (dev_name_end) {
471 		if (strlen(dev_name_end) > 1) {
472 			fsopt->server_path = kstrdup(dev_name_end, GFP_KERNEL);
473 			if (!fsopt->server_path) {
474 				err = -ENOMEM;
475 				goto out;
476 			}
477 		}
478 	} else {
479 		dev_name_end = dev_name + strlen(dev_name);
480 	}
481 	err = -EINVAL;
482 	dev_name_end--;		/* back up to ':' separator */
483 	if (dev_name_end < dev_name || *dev_name_end != ':') {
484 		pr_err("device name is missing path (no : separator in %s)\n",
485 				dev_name);
486 		goto out;
487 	}
488 	dout("device name '%.*s'\n", (int)(dev_name_end - dev_name), dev_name);
489 	if (fsopt->server_path)
490 		dout("server path '%s'\n", fsopt->server_path);
491 
492 	*popt = ceph_parse_options(options, dev_name, dev_name_end,
493 				 parse_fsopt_token, (void *)fsopt);
494 	if (IS_ERR(*popt)) {
495 		err = PTR_ERR(*popt);
496 		goto out;
497 	}
498 
499 	/* success */
500 	*pfsopt = fsopt;
501 	return 0;
502 
503 out:
504 	destroy_mount_options(fsopt);
505 	return err;
506 }
507 
508 /**
509  * ceph_show_options - Show mount options in /proc/mounts
510  * @m: seq_file to write to
511  * @root: root of that (sub)tree
512  */
513 static int ceph_show_options(struct seq_file *m, struct dentry *root)
514 {
515 	struct ceph_fs_client *fsc = ceph_sb_to_client(root->d_sb);
516 	struct ceph_mount_options *fsopt = fsc->mount_options;
517 	size_t pos;
518 	int ret;
519 
520 	/* a comma between MNT/MS and client options */
521 	seq_putc(m, ',');
522 	pos = m->count;
523 
524 	ret = ceph_print_client_options(m, fsc->client);
525 	if (ret)
526 		return ret;
527 
528 	/* retract our comma if no client options */
529 	if (m->count == pos)
530 		m->count--;
531 
532 	if (fsopt->flags & CEPH_MOUNT_OPT_DIRSTAT)
533 		seq_puts(m, ",dirstat");
534 	if ((fsopt->flags & CEPH_MOUNT_OPT_RBYTES))
535 		seq_puts(m, ",rbytes");
536 	if (fsopt->flags & CEPH_MOUNT_OPT_NOASYNCREADDIR)
537 		seq_puts(m, ",noasyncreaddir");
538 	if ((fsopt->flags & CEPH_MOUNT_OPT_DCACHE) == 0)
539 		seq_puts(m, ",nodcache");
540 	if (fsopt->flags & CEPH_MOUNT_OPT_INO32)
541 		seq_puts(m, ",ino32");
542 	if (fsopt->flags & CEPH_MOUNT_OPT_FSCACHE) {
543 		seq_show_option(m, "fsc", fsopt->fscache_uniq);
544 	}
545 	if (fsopt->flags & CEPH_MOUNT_OPT_NOPOOLPERM)
546 		seq_puts(m, ",nopoolperm");
547 	if (fsopt->flags & CEPH_MOUNT_OPT_NOQUOTADF)
548 		seq_puts(m, ",noquotadf");
549 
550 #ifdef CONFIG_CEPH_FS_POSIX_ACL
551 	if (fsopt->sb_flags & SB_POSIXACL)
552 		seq_puts(m, ",acl");
553 	else
554 		seq_puts(m, ",noacl");
555 #endif
556 
557 	if (fsopt->mds_namespace)
558 		seq_show_option(m, "mds_namespace", fsopt->mds_namespace);
559 	if (fsopt->wsize != CEPH_MAX_WRITE_SIZE)
560 		seq_printf(m, ",wsize=%d", fsopt->wsize);
561 	if (fsopt->rsize != CEPH_MAX_READ_SIZE)
562 		seq_printf(m, ",rsize=%d", fsopt->rsize);
563 	if (fsopt->rasize != CEPH_RASIZE_DEFAULT)
564 		seq_printf(m, ",rasize=%d", fsopt->rasize);
565 	if (fsopt->congestion_kb != default_congestion_kb())
566 		seq_printf(m, ",write_congestion_kb=%d", fsopt->congestion_kb);
567 	if (fsopt->caps_wanted_delay_min != CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT)
568 		seq_printf(m, ",caps_wanted_delay_min=%d",
569 			 fsopt->caps_wanted_delay_min);
570 	if (fsopt->caps_wanted_delay_max != CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT)
571 		seq_printf(m, ",caps_wanted_delay_max=%d",
572 			   fsopt->caps_wanted_delay_max);
573 	if (fsopt->max_readdir != CEPH_MAX_READDIR_DEFAULT)
574 		seq_printf(m, ",readdir_max_entries=%d", fsopt->max_readdir);
575 	if (fsopt->max_readdir_bytes != CEPH_MAX_READDIR_BYTES_DEFAULT)
576 		seq_printf(m, ",readdir_max_bytes=%d", fsopt->max_readdir_bytes);
577 	if (strcmp(fsopt->snapdir_name, CEPH_SNAPDIRNAME_DEFAULT))
578 		seq_show_option(m, "snapdirname", fsopt->snapdir_name);
579 
580 	return 0;
581 }
582 
583 /*
584  * handle any mon messages the standard library doesn't understand.
585  * return error if we don't either.
586  */
587 static int extra_mon_dispatch(struct ceph_client *client, struct ceph_msg *msg)
588 {
589 	struct ceph_fs_client *fsc = client->private;
590 	int type = le16_to_cpu(msg->hdr.type);
591 
592 	switch (type) {
593 	case CEPH_MSG_MDS_MAP:
594 		ceph_mdsc_handle_mdsmap(fsc->mdsc, msg);
595 		return 0;
596 	case CEPH_MSG_FS_MAP_USER:
597 		ceph_mdsc_handle_fsmap(fsc->mdsc, msg);
598 		return 0;
599 	default:
600 		return -1;
601 	}
602 }
603 
604 /*
605  * create a new fs client
606  */
607 static struct ceph_fs_client *create_fs_client(struct ceph_mount_options *fsopt,
608 					struct ceph_options *opt)
609 {
610 	struct ceph_fs_client *fsc;
611 	int page_count;
612 	size_t size;
613 	int err = -ENOMEM;
614 
615 	fsc = kzalloc(sizeof(*fsc), GFP_KERNEL);
616 	if (!fsc)
617 		return ERR_PTR(-ENOMEM);
618 
619 	fsc->client = ceph_create_client(opt, fsc);
620 	if (IS_ERR(fsc->client)) {
621 		err = PTR_ERR(fsc->client);
622 		goto fail;
623 	}
624 
625 	fsc->client->extra_mon_dispatch = extra_mon_dispatch;
626 	fsc->client->osdc.abort_on_full = true;
627 
628 	if (!fsopt->mds_namespace) {
629 		ceph_monc_want_map(&fsc->client->monc, CEPH_SUB_MDSMAP,
630 				   0, true);
631 	} else {
632 		ceph_monc_want_map(&fsc->client->monc, CEPH_SUB_FSMAP,
633 				   0, false);
634 	}
635 
636 	fsc->mount_options = fsopt;
637 
638 	fsc->sb = NULL;
639 	fsc->mount_state = CEPH_MOUNT_MOUNTING;
640 
641 	atomic_long_set(&fsc->writeback_count, 0);
642 
643 	err = -ENOMEM;
644 	/*
645 	 * The number of concurrent works can be high but they don't need
646 	 * to be processed in parallel, limit concurrency.
647 	 */
648 	fsc->wb_wq = alloc_workqueue("ceph-writeback", 0, 1);
649 	if (!fsc->wb_wq)
650 		goto fail_client;
651 	fsc->pg_inv_wq = alloc_workqueue("ceph-pg-invalid", 0, 1);
652 	if (!fsc->pg_inv_wq)
653 		goto fail_wb_wq;
654 	fsc->trunc_wq = alloc_workqueue("ceph-trunc", 0, 1);
655 	if (!fsc->trunc_wq)
656 		goto fail_pg_inv_wq;
657 
658 	/* set up mempools */
659 	err = -ENOMEM;
660 	page_count = fsc->mount_options->wsize >> PAGE_SHIFT;
661 	size = sizeof (struct page *) * (page_count ? page_count : 1);
662 	fsc->wb_pagevec_pool = mempool_create_kmalloc_pool(10, size);
663 	if (!fsc->wb_pagevec_pool)
664 		goto fail_trunc_wq;
665 
666 	/* caps */
667 	fsc->min_caps = fsopt->max_readdir;
668 
669 	return fsc;
670 
671 fail_trunc_wq:
672 	destroy_workqueue(fsc->trunc_wq);
673 fail_pg_inv_wq:
674 	destroy_workqueue(fsc->pg_inv_wq);
675 fail_wb_wq:
676 	destroy_workqueue(fsc->wb_wq);
677 fail_client:
678 	ceph_destroy_client(fsc->client);
679 fail:
680 	kfree(fsc);
681 	return ERR_PTR(err);
682 }
683 
684 static void flush_fs_workqueues(struct ceph_fs_client *fsc)
685 {
686 	flush_workqueue(fsc->wb_wq);
687 	flush_workqueue(fsc->pg_inv_wq);
688 	flush_workqueue(fsc->trunc_wq);
689 }
690 
691 static void destroy_fs_client(struct ceph_fs_client *fsc)
692 {
693 	dout("destroy_fs_client %p\n", fsc);
694 
695 	destroy_workqueue(fsc->wb_wq);
696 	destroy_workqueue(fsc->pg_inv_wq);
697 	destroy_workqueue(fsc->trunc_wq);
698 
699 	mempool_destroy(fsc->wb_pagevec_pool);
700 
701 	destroy_mount_options(fsc->mount_options);
702 
703 	ceph_destroy_client(fsc->client);
704 
705 	kfree(fsc);
706 	dout("destroy_fs_client %p done\n", fsc);
707 }
708 
709 /*
710  * caches
711  */
712 struct kmem_cache *ceph_inode_cachep;
713 struct kmem_cache *ceph_cap_cachep;
714 struct kmem_cache *ceph_cap_flush_cachep;
715 struct kmem_cache *ceph_dentry_cachep;
716 struct kmem_cache *ceph_file_cachep;
717 struct kmem_cache *ceph_dir_file_cachep;
718 
719 static void ceph_inode_init_once(void *foo)
720 {
721 	struct ceph_inode_info *ci = foo;
722 	inode_init_once(&ci->vfs_inode);
723 }
724 
725 static int __init init_caches(void)
726 {
727 	int error = -ENOMEM;
728 
729 	ceph_inode_cachep = kmem_cache_create("ceph_inode_info",
730 				      sizeof(struct ceph_inode_info),
731 				      __alignof__(struct ceph_inode_info),
732 				      SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
733 				      SLAB_ACCOUNT, ceph_inode_init_once);
734 	if (!ceph_inode_cachep)
735 		return -ENOMEM;
736 
737 	ceph_cap_cachep = KMEM_CACHE(ceph_cap, SLAB_MEM_SPREAD);
738 	if (!ceph_cap_cachep)
739 		goto bad_cap;
740 	ceph_cap_flush_cachep = KMEM_CACHE(ceph_cap_flush,
741 					   SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
742 	if (!ceph_cap_flush_cachep)
743 		goto bad_cap_flush;
744 
745 	ceph_dentry_cachep = KMEM_CACHE(ceph_dentry_info,
746 					SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD);
747 	if (!ceph_dentry_cachep)
748 		goto bad_dentry;
749 
750 	ceph_file_cachep = KMEM_CACHE(ceph_file_info, SLAB_MEM_SPREAD);
751 	if (!ceph_file_cachep)
752 		goto bad_file;
753 
754 	ceph_dir_file_cachep = KMEM_CACHE(ceph_dir_file_info, SLAB_MEM_SPREAD);
755 	if (!ceph_dir_file_cachep)
756 		goto bad_dir_file;
757 
758 	error = ceph_fscache_register();
759 	if (error)
760 		goto bad_fscache;
761 
762 	return 0;
763 
764 bad_fscache:
765 	kmem_cache_destroy(ceph_dir_file_cachep);
766 bad_dir_file:
767 	kmem_cache_destroy(ceph_file_cachep);
768 bad_file:
769 	kmem_cache_destroy(ceph_dentry_cachep);
770 bad_dentry:
771 	kmem_cache_destroy(ceph_cap_flush_cachep);
772 bad_cap_flush:
773 	kmem_cache_destroy(ceph_cap_cachep);
774 bad_cap:
775 	kmem_cache_destroy(ceph_inode_cachep);
776 	return error;
777 }
778 
779 static void destroy_caches(void)
780 {
781 	/*
782 	 * Make sure all delayed rcu free inodes are flushed before we
783 	 * destroy cache.
784 	 */
785 	rcu_barrier();
786 
787 	kmem_cache_destroy(ceph_inode_cachep);
788 	kmem_cache_destroy(ceph_cap_cachep);
789 	kmem_cache_destroy(ceph_cap_flush_cachep);
790 	kmem_cache_destroy(ceph_dentry_cachep);
791 	kmem_cache_destroy(ceph_file_cachep);
792 	kmem_cache_destroy(ceph_dir_file_cachep);
793 
794 	ceph_fscache_unregister();
795 }
796 
797 
798 /*
799  * ceph_umount_begin - initiate forced umount.  Tear down down the
800  * mount, skipping steps that may hang while waiting for server(s).
801  */
802 static void ceph_umount_begin(struct super_block *sb)
803 {
804 	struct ceph_fs_client *fsc = ceph_sb_to_client(sb);
805 
806 	dout("ceph_umount_begin - starting forced umount\n");
807 	if (!fsc)
808 		return;
809 	fsc->mount_state = CEPH_MOUNT_SHUTDOWN;
810 	ceph_osdc_abort_requests(&fsc->client->osdc, -EIO);
811 	ceph_mdsc_force_umount(fsc->mdsc);
812 	return;
813 }
814 
815 static const struct super_operations ceph_super_ops = {
816 	.alloc_inode	= ceph_alloc_inode,
817 	.destroy_inode	= ceph_destroy_inode,
818 	.write_inode    = ceph_write_inode,
819 	.drop_inode	= ceph_drop_inode,
820 	.sync_fs        = ceph_sync_fs,
821 	.put_super	= ceph_put_super,
822 	.show_options   = ceph_show_options,
823 	.statfs		= ceph_statfs,
824 	.umount_begin   = ceph_umount_begin,
825 };
826 
827 /*
828  * Bootstrap mount by opening the root directory.  Note the mount
829  * @started time from caller, and time out if this takes too long.
830  */
831 static struct dentry *open_root_dentry(struct ceph_fs_client *fsc,
832 				       const char *path,
833 				       unsigned long started)
834 {
835 	struct ceph_mds_client *mdsc = fsc->mdsc;
836 	struct ceph_mds_request *req = NULL;
837 	int err;
838 	struct dentry *root;
839 
840 	/* open dir */
841 	dout("open_root_inode opening '%s'\n", path);
842 	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_GETATTR, USE_ANY_MDS);
843 	if (IS_ERR(req))
844 		return ERR_CAST(req);
845 	req->r_path1 = kstrdup(path, GFP_NOFS);
846 	if (!req->r_path1) {
847 		root = ERR_PTR(-ENOMEM);
848 		goto out;
849 	}
850 
851 	req->r_ino1.ino = CEPH_INO_ROOT;
852 	req->r_ino1.snap = CEPH_NOSNAP;
853 	req->r_started = started;
854 	req->r_timeout = fsc->client->options->mount_timeout;
855 	req->r_args.getattr.mask = cpu_to_le32(CEPH_STAT_CAP_INODE);
856 	req->r_num_caps = 2;
857 	err = ceph_mdsc_do_request(mdsc, NULL, req);
858 	if (err == 0) {
859 		struct inode *inode = req->r_target_inode;
860 		req->r_target_inode = NULL;
861 		dout("open_root_inode success\n");
862 		root = d_make_root(inode);
863 		if (!root) {
864 			root = ERR_PTR(-ENOMEM);
865 			goto out;
866 		}
867 		dout("open_root_inode success, root dentry is %p\n", root);
868 	} else {
869 		root = ERR_PTR(err);
870 	}
871 out:
872 	ceph_mdsc_put_request(req);
873 	return root;
874 }
875 
876 
877 
878 
879 /*
880  * mount: join the ceph cluster, and open root directory.
881  */
882 static struct dentry *ceph_real_mount(struct ceph_fs_client *fsc)
883 {
884 	int err;
885 	unsigned long started = jiffies;  /* note the start time */
886 	struct dentry *root;
887 
888 	dout("mount start %p\n", fsc);
889 	mutex_lock(&fsc->client->mount_mutex);
890 
891 	if (!fsc->sb->s_root) {
892 		const char *path;
893 		err = __ceph_open_session(fsc->client, started);
894 		if (err < 0)
895 			goto out;
896 
897 		/* setup fscache */
898 		if (fsc->mount_options->flags & CEPH_MOUNT_OPT_FSCACHE) {
899 			err = ceph_fscache_register_fs(fsc);
900 			if (err < 0)
901 				goto out;
902 		}
903 
904 		if (!fsc->mount_options->server_path) {
905 			path = "";
906 			dout("mount opening path \\t\n");
907 		} else {
908 			path = fsc->mount_options->server_path + 1;
909 			dout("mount opening path %s\n", path);
910 		}
911 
912 		err = ceph_fs_debugfs_init(fsc);
913 		if (err < 0)
914 			goto out;
915 
916 		root = open_root_dentry(fsc, path, started);
917 		if (IS_ERR(root)) {
918 			err = PTR_ERR(root);
919 			goto out;
920 		}
921 		fsc->sb->s_root = dget(root);
922 	} else {
923 		root = dget(fsc->sb->s_root);
924 	}
925 
926 	fsc->mount_state = CEPH_MOUNT_MOUNTED;
927 	dout("mount success\n");
928 	mutex_unlock(&fsc->client->mount_mutex);
929 	return root;
930 
931 out:
932 	mutex_unlock(&fsc->client->mount_mutex);
933 	return ERR_PTR(err);
934 }
935 
936 static int ceph_set_super(struct super_block *s, void *data)
937 {
938 	struct ceph_fs_client *fsc = data;
939 	int ret;
940 
941 	dout("set_super %p data %p\n", s, data);
942 
943 	s->s_flags = fsc->mount_options->sb_flags;
944 	s->s_maxbytes = 1ULL << 40;  /* temp value until we get mdsmap */
945 
946 	s->s_xattr = ceph_xattr_handlers;
947 	s->s_fs_info = fsc;
948 	fsc->sb = s;
949 
950 	s->s_op = &ceph_super_ops;
951 	s->s_d_op = &ceph_dentry_ops;
952 	s->s_export_op = &ceph_export_ops;
953 
954 	s->s_time_gran = 1000;  /* 1000 ns == 1 us */
955 
956 	ret = set_anon_super(s, NULL);  /* what is that second arg for? */
957 	if (ret != 0)
958 		goto fail;
959 
960 	return ret;
961 
962 fail:
963 	s->s_fs_info = NULL;
964 	fsc->sb = NULL;
965 	return ret;
966 }
967 
968 /*
969  * share superblock if same fs AND options
970  */
971 static int ceph_compare_super(struct super_block *sb, void *data)
972 {
973 	struct ceph_fs_client *new = data;
974 	struct ceph_mount_options *fsopt = new->mount_options;
975 	struct ceph_options *opt = new->client->options;
976 	struct ceph_fs_client *other = ceph_sb_to_client(sb);
977 
978 	dout("ceph_compare_super %p\n", sb);
979 
980 	if (compare_mount_options(fsopt, opt, other)) {
981 		dout("monitor(s)/mount options don't match\n");
982 		return 0;
983 	}
984 	if ((opt->flags & CEPH_OPT_FSID) &&
985 	    ceph_fsid_compare(&opt->fsid, &other->client->fsid)) {
986 		dout("fsid doesn't match\n");
987 		return 0;
988 	}
989 	if (fsopt->sb_flags != other->mount_options->sb_flags) {
990 		dout("flags differ\n");
991 		return 0;
992 	}
993 	return 1;
994 }
995 
996 /*
997  * construct our own bdi so we can control readahead, etc.
998  */
999 static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0);
1000 
1001 static int ceph_setup_bdi(struct super_block *sb, struct ceph_fs_client *fsc)
1002 {
1003 	int err;
1004 
1005 	err = super_setup_bdi_name(sb, "ceph-%ld",
1006 				   atomic_long_inc_return(&bdi_seq));
1007 	if (err)
1008 		return err;
1009 
1010 	/* set ra_pages based on rasize mount option? */
1011 	sb->s_bdi->ra_pages = fsc->mount_options->rasize >> PAGE_SHIFT;
1012 
1013 	/* set io_pages based on max osd read size */
1014 	sb->s_bdi->io_pages = fsc->mount_options->rsize >> PAGE_SHIFT;
1015 
1016 	return 0;
1017 }
1018 
1019 static struct dentry *ceph_mount(struct file_system_type *fs_type,
1020 		       int flags, const char *dev_name, void *data)
1021 {
1022 	struct super_block *sb;
1023 	struct ceph_fs_client *fsc;
1024 	struct dentry *res;
1025 	int err;
1026 	int (*compare_super)(struct super_block *, void *) = ceph_compare_super;
1027 	struct ceph_mount_options *fsopt = NULL;
1028 	struct ceph_options *opt = NULL;
1029 
1030 	dout("ceph_mount\n");
1031 
1032 #ifdef CONFIG_CEPH_FS_POSIX_ACL
1033 	flags |= SB_POSIXACL;
1034 #endif
1035 	err = parse_mount_options(&fsopt, &opt, flags, data, dev_name);
1036 	if (err < 0) {
1037 		res = ERR_PTR(err);
1038 		goto out_final;
1039 	}
1040 
1041 	/* create client (which we may/may not use) */
1042 	fsc = create_fs_client(fsopt, opt);
1043 	if (IS_ERR(fsc)) {
1044 		res = ERR_CAST(fsc);
1045 		destroy_mount_options(fsopt);
1046 		ceph_destroy_options(opt);
1047 		goto out_final;
1048 	}
1049 
1050 	err = ceph_mdsc_init(fsc);
1051 	if (err < 0) {
1052 		res = ERR_PTR(err);
1053 		goto out;
1054 	}
1055 
1056 	if (ceph_test_opt(fsc->client, NOSHARE))
1057 		compare_super = NULL;
1058 	sb = sget(fs_type, compare_super, ceph_set_super, flags, fsc);
1059 	if (IS_ERR(sb)) {
1060 		res = ERR_CAST(sb);
1061 		goto out;
1062 	}
1063 
1064 	if (ceph_sb_to_client(sb) != fsc) {
1065 		ceph_mdsc_destroy(fsc);
1066 		destroy_fs_client(fsc);
1067 		fsc = ceph_sb_to_client(sb);
1068 		dout("get_sb got existing client %p\n", fsc);
1069 	} else {
1070 		dout("get_sb using new client %p\n", fsc);
1071 		err = ceph_setup_bdi(sb, fsc);
1072 		if (err < 0) {
1073 			res = ERR_PTR(err);
1074 			goto out_splat;
1075 		}
1076 	}
1077 
1078 	res = ceph_real_mount(fsc);
1079 	if (IS_ERR(res))
1080 		goto out_splat;
1081 	dout("root %p inode %p ino %llx.%llx\n", res,
1082 	     d_inode(res), ceph_vinop(d_inode(res)));
1083 	return res;
1084 
1085 out_splat:
1086 	ceph_mdsc_close_sessions(fsc->mdsc);
1087 	deactivate_locked_super(sb);
1088 	goto out_final;
1089 
1090 out:
1091 	ceph_mdsc_destroy(fsc);
1092 	destroy_fs_client(fsc);
1093 out_final:
1094 	dout("ceph_mount fail %ld\n", PTR_ERR(res));
1095 	return res;
1096 }
1097 
1098 static void ceph_kill_sb(struct super_block *s)
1099 {
1100 	struct ceph_fs_client *fsc = ceph_sb_to_client(s);
1101 	dev_t dev = s->s_dev;
1102 
1103 	dout("kill_sb %p\n", s);
1104 
1105 	ceph_mdsc_pre_umount(fsc->mdsc);
1106 	flush_fs_workqueues(fsc);
1107 
1108 	generic_shutdown_super(s);
1109 
1110 	fsc->client->extra_mon_dispatch = NULL;
1111 	ceph_fs_debugfs_cleanup(fsc);
1112 
1113 	ceph_fscache_unregister_fs(fsc);
1114 
1115 	ceph_mdsc_destroy(fsc);
1116 
1117 	destroy_fs_client(fsc);
1118 	free_anon_bdev(dev);
1119 }
1120 
1121 static struct file_system_type ceph_fs_type = {
1122 	.owner		= THIS_MODULE,
1123 	.name		= "ceph",
1124 	.mount		= ceph_mount,
1125 	.kill_sb	= ceph_kill_sb,
1126 	.fs_flags	= FS_RENAME_DOES_D_MOVE,
1127 };
1128 MODULE_ALIAS_FS("ceph");
1129 
1130 static int __init init_ceph(void)
1131 {
1132 	int ret = init_caches();
1133 	if (ret)
1134 		goto out;
1135 
1136 	ceph_flock_init();
1137 	ceph_xattr_init();
1138 	ret = register_filesystem(&ceph_fs_type);
1139 	if (ret)
1140 		goto out_xattr;
1141 
1142 	pr_info("loaded (mds proto %d)\n", CEPH_MDSC_PROTOCOL);
1143 
1144 	return 0;
1145 
1146 out_xattr:
1147 	ceph_xattr_exit();
1148 	destroy_caches();
1149 out:
1150 	return ret;
1151 }
1152 
1153 static void __exit exit_ceph(void)
1154 {
1155 	dout("exit_ceph\n");
1156 	unregister_filesystem(&ceph_fs_type);
1157 	ceph_xattr_exit();
1158 	destroy_caches();
1159 }
1160 
1161 module_init(init_ceph);
1162 module_exit(exit_ceph);
1163 
1164 MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
1165 MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
1166 MODULE_AUTHOR("Patience Warnick <patience@newdream.net>");
1167 MODULE_DESCRIPTION("Ceph filesystem for Linux");
1168 MODULE_LICENSE("GPL");
1169