xref: /openbmc/linux/fs/gfs2/sys.c (revision e75d5ae8)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
4  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
5  */
6 
7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8 
9 #include <linux/sched.h>
10 #include <linux/cred.h>
11 #include <linux/spinlock.h>
12 #include <linux/completion.h>
13 #include <linux/buffer_head.h>
14 #include <linux/module.h>
15 #include <linux/kobject.h>
16 #include <linux/uaccess.h>
17 #include <linux/gfs2_ondisk.h>
18 #include <linux/blkdev.h>
19 
20 #include "gfs2.h"
21 #include "incore.h"
22 #include "sys.h"
23 #include "super.h"
24 #include "glock.h"
25 #include "quota.h"
26 #include "util.h"
27 #include "glops.h"
28 #include "recovery.h"
29 
30 struct gfs2_attr {
31 	struct attribute attr;
32 	ssize_t (*show)(struct gfs2_sbd *, char *);
33 	ssize_t (*store)(struct gfs2_sbd *, const char *, size_t);
34 };
35 
36 static ssize_t gfs2_attr_show(struct kobject *kobj, struct attribute *attr,
37 			      char *buf)
38 {
39 	struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj);
40 	struct gfs2_attr *a = container_of(attr, struct gfs2_attr, attr);
41 	return a->show ? a->show(sdp, buf) : 0;
42 }
43 
44 static ssize_t gfs2_attr_store(struct kobject *kobj, struct attribute *attr,
45 			       const char *buf, size_t len)
46 {
47 	struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj);
48 	struct gfs2_attr *a = container_of(attr, struct gfs2_attr, attr);
49 	return a->store ? a->store(sdp, buf, len) : len;
50 }
51 
52 static const struct sysfs_ops gfs2_attr_ops = {
53 	.show  = gfs2_attr_show,
54 	.store = gfs2_attr_store,
55 };
56 
57 
58 static struct kset *gfs2_kset;
59 
60 static ssize_t id_show(struct gfs2_sbd *sdp, char *buf)
61 {
62 	return snprintf(buf, PAGE_SIZE, "%u:%u\n",
63 			MAJOR(sdp->sd_vfs->s_dev), MINOR(sdp->sd_vfs->s_dev));
64 }
65 
66 static ssize_t status_show(struct gfs2_sbd *sdp, char *buf)
67 {
68 	unsigned long f = sdp->sd_flags;
69 	ssize_t s;
70 
71 	s = snprintf(buf, PAGE_SIZE,
72 		     "Journal Checked:          %d\n"
73 		     "Journal Live:             %d\n"
74 		     "Journal ID:               %d\n"
75 		     "Spectator:                %d\n"
76 		     "Withdrawn:                %d\n"
77 		     "No barriers:              %d\n"
78 		     "No recovery:              %d\n"
79 		     "Demote:                   %d\n"
80 		     "No Journal ID:            %d\n"
81 		     "Mounted RO:               %d\n"
82 		     "RO Recovery:              %d\n"
83 		     "Skip DLM Unlock:          %d\n"
84 		     "Force AIL Flush:          %d\n"
85 		     "FS Frozen:                %d\n"
86 		     "Withdrawing:              %d\n"
87 		     "Withdraw In Prog:         %d\n"
88 		     "Remote Withdraw:          %d\n"
89 		     "Withdraw Recovery:        %d\n"
90 		     "sd_log_error:             %d\n"
91 		     "sd_log_flush_lock:        %d\n"
92 		     "sd_log_num_revoke:        %u\n"
93 		     "sd_log_in_flight:         %d\n"
94 		     "sd_log_blks_needed:       %d\n"
95 		     "sd_log_blks_free:         %d\n"
96 		     "sd_log_flush_head:        %d\n"
97 		     "sd_log_flush_tail:        %d\n"
98 		     "sd_log_blks_reserved:     %d\n"
99 		     "sd_log_revokes_available: %d\n",
100 		     test_bit(SDF_JOURNAL_CHECKED, &f),
101 		     test_bit(SDF_JOURNAL_LIVE, &f),
102 		     (sdp->sd_jdesc ? sdp->sd_jdesc->jd_jid : 0),
103 		     (sdp->sd_args.ar_spectator ? 1 : 0),
104 		     test_bit(SDF_WITHDRAWN, &f),
105 		     test_bit(SDF_NOBARRIERS, &f),
106 		     test_bit(SDF_NORECOVERY, &f),
107 		     test_bit(SDF_DEMOTE, &f),
108 		     test_bit(SDF_NOJOURNALID, &f),
109 		     (sb_rdonly(sdp->sd_vfs) ? 1 : 0),
110 		     test_bit(SDF_RORECOVERY, &f),
111 		     test_bit(SDF_SKIP_DLM_UNLOCK, &f),
112 		     test_bit(SDF_FORCE_AIL_FLUSH, &f),
113 		     test_bit(SDF_FS_FROZEN, &f),
114 		     test_bit(SDF_WITHDRAWING, &f),
115 		     test_bit(SDF_WITHDRAW_IN_PROG, &f),
116 		     test_bit(SDF_REMOTE_WITHDRAW, &f),
117 		     test_bit(SDF_WITHDRAW_RECOVERY, &f),
118 		     sdp->sd_log_error,
119 		     rwsem_is_locked(&sdp->sd_log_flush_lock),
120 		     sdp->sd_log_num_revoke,
121 		     atomic_read(&sdp->sd_log_in_flight),
122 		     atomic_read(&sdp->sd_log_blks_needed),
123 		     atomic_read(&sdp->sd_log_blks_free),
124 		     sdp->sd_log_flush_head,
125 		     sdp->sd_log_flush_tail,
126 		     sdp->sd_log_blks_reserved,
127 		     atomic_read(&sdp->sd_log_revokes_available));
128 	return s;
129 }
130 
131 static ssize_t fsname_show(struct gfs2_sbd *sdp, char *buf)
132 {
133 	return snprintf(buf, PAGE_SIZE, "%s\n", sdp->sd_fsname);
134 }
135 
136 static ssize_t uuid_show(struct gfs2_sbd *sdp, char *buf)
137 {
138 	struct super_block *s = sdp->sd_vfs;
139 
140 	buf[0] = '\0';
141 	if (uuid_is_null(&s->s_uuid))
142 		return 0;
143 	return snprintf(buf, PAGE_SIZE, "%pUB\n", &s->s_uuid);
144 }
145 
146 static ssize_t freeze_show(struct gfs2_sbd *sdp, char *buf)
147 {
148 	struct super_block *sb = sdp->sd_vfs;
149 	int frozen = (sb->s_writers.frozen == SB_UNFROZEN) ? 0 : 1;
150 
151 	return snprintf(buf, PAGE_SIZE, "%d\n", frozen);
152 }
153 
154 static ssize_t freeze_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
155 {
156 	int error, n;
157 
158 	error = kstrtoint(buf, 0, &n);
159 	if (error)
160 		return error;
161 
162 	if (!capable(CAP_SYS_ADMIN))
163 		return -EPERM;
164 
165 	switch (n) {
166 	case 0:
167 		error = thaw_super(sdp->sd_vfs);
168 		break;
169 	case 1:
170 		error = freeze_super(sdp->sd_vfs);
171 		break;
172 	default:
173 		return -EINVAL;
174 	}
175 
176 	if (error) {
177 		fs_warn(sdp, "freeze %d error %d\n", n, error);
178 		return error;
179 	}
180 
181 	return len;
182 }
183 
184 static ssize_t withdraw_show(struct gfs2_sbd *sdp, char *buf)
185 {
186 	unsigned int b = gfs2_withdrawn(sdp);
187 	return snprintf(buf, PAGE_SIZE, "%u\n", b);
188 }
189 
190 static ssize_t withdraw_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
191 {
192 	int error, val;
193 
194 	if (!capable(CAP_SYS_ADMIN))
195 		return -EPERM;
196 
197 	error = kstrtoint(buf, 0, &val);
198 	if (error)
199 		return error;
200 
201 	if (val != 1)
202 		return -EINVAL;
203 
204 	gfs2_lm(sdp, "withdrawing from cluster at user's request\n");
205 	gfs2_withdraw(sdp);
206 
207 	return len;
208 }
209 
210 static ssize_t statfs_sync_store(struct gfs2_sbd *sdp, const char *buf,
211 				 size_t len)
212 {
213 	int error, val;
214 
215 	if (!capable(CAP_SYS_ADMIN))
216 		return -EPERM;
217 
218 	error = kstrtoint(buf, 0, &val);
219 	if (error)
220 		return error;
221 
222 	if (val != 1)
223 		return -EINVAL;
224 
225 	gfs2_statfs_sync(sdp->sd_vfs, 0);
226 	return len;
227 }
228 
229 static ssize_t quota_sync_store(struct gfs2_sbd *sdp, const char *buf,
230 				size_t len)
231 {
232 	int error, val;
233 
234 	if (!capable(CAP_SYS_ADMIN))
235 		return -EPERM;
236 
237 	error = kstrtoint(buf, 0, &val);
238 	if (error)
239 		return error;
240 
241 	if (val != 1)
242 		return -EINVAL;
243 
244 	gfs2_quota_sync(sdp->sd_vfs, 0);
245 	return len;
246 }
247 
248 static ssize_t quota_refresh_user_store(struct gfs2_sbd *sdp, const char *buf,
249 					size_t len)
250 {
251 	struct kqid qid;
252 	int error;
253 	u32 id;
254 
255 	if (!capable(CAP_SYS_ADMIN))
256 		return -EPERM;
257 
258 	error = kstrtou32(buf, 0, &id);
259 	if (error)
260 		return error;
261 
262 	qid = make_kqid(current_user_ns(), USRQUOTA, id);
263 	if (!qid_valid(qid))
264 		return -EINVAL;
265 
266 	error = gfs2_quota_refresh(sdp, qid);
267 	return error ? error : len;
268 }
269 
270 static ssize_t quota_refresh_group_store(struct gfs2_sbd *sdp, const char *buf,
271 					 size_t len)
272 {
273 	struct kqid qid;
274 	int error;
275 	u32 id;
276 
277 	if (!capable(CAP_SYS_ADMIN))
278 		return -EPERM;
279 
280 	error = kstrtou32(buf, 0, &id);
281 	if (error)
282 		return error;
283 
284 	qid = make_kqid(current_user_ns(), GRPQUOTA, id);
285 	if (!qid_valid(qid))
286 		return -EINVAL;
287 
288 	error = gfs2_quota_refresh(sdp, qid);
289 	return error ? error : len;
290 }
291 
292 static ssize_t demote_rq_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
293 {
294 	struct gfs2_glock *gl;
295 	const struct gfs2_glock_operations *glops;
296 	unsigned int glmode;
297 	unsigned int gltype;
298 	unsigned long long glnum;
299 	char mode[16];
300 	int rv;
301 
302 	if (!capable(CAP_SYS_ADMIN))
303 		return -EPERM;
304 
305 	rv = sscanf(buf, "%u:%llu %15s", &gltype, &glnum,
306 		    mode);
307 	if (rv != 3)
308 		return -EINVAL;
309 
310 	if (strcmp(mode, "EX") == 0)
311 		glmode = LM_ST_UNLOCKED;
312 	else if ((strcmp(mode, "CW") == 0) || (strcmp(mode, "DF") == 0))
313 		glmode = LM_ST_DEFERRED;
314 	else if ((strcmp(mode, "PR") == 0) || (strcmp(mode, "SH") == 0))
315 		glmode = LM_ST_SHARED;
316 	else
317 		return -EINVAL;
318 
319 	if (gltype > LM_TYPE_JOURNAL)
320 		return -EINVAL;
321 	if (gltype == LM_TYPE_NONDISK && glnum == GFS2_FREEZE_LOCK)
322 		glops = &gfs2_freeze_glops;
323 	else
324 		glops = gfs2_glops_list[gltype];
325 	if (glops == NULL)
326 		return -EINVAL;
327 	if (!test_and_set_bit(SDF_DEMOTE, &sdp->sd_flags))
328 		fs_info(sdp, "demote interface used\n");
329 	rv = gfs2_glock_get(sdp, glnum, glops, 0, &gl);
330 	if (rv)
331 		return rv;
332 	gfs2_glock_cb(gl, glmode);
333 	gfs2_glock_put(gl);
334 	return len;
335 }
336 
337 
338 #define GFS2_ATTR(name, mode, show, store) \
339 static struct gfs2_attr gfs2_attr_##name = __ATTR(name, mode, show, store)
340 
341 GFS2_ATTR(id,                  0444, id_show,       NULL);
342 GFS2_ATTR(fsname,              0444, fsname_show,   NULL);
343 GFS2_ATTR(uuid,                0444, uuid_show,     NULL);
344 GFS2_ATTR(freeze,              0644, freeze_show,   freeze_store);
345 GFS2_ATTR(withdraw,            0644, withdraw_show, withdraw_store);
346 GFS2_ATTR(statfs_sync,         0200, NULL,          statfs_sync_store);
347 GFS2_ATTR(quota_sync,          0200, NULL,          quota_sync_store);
348 GFS2_ATTR(quota_refresh_user,  0200, NULL,          quota_refresh_user_store);
349 GFS2_ATTR(quota_refresh_group, 0200, NULL,          quota_refresh_group_store);
350 GFS2_ATTR(demote_rq,           0200, NULL,	    demote_rq_store);
351 GFS2_ATTR(status,              0400, status_show,   NULL);
352 
353 static struct attribute *gfs2_attrs[] = {
354 	&gfs2_attr_id.attr,
355 	&gfs2_attr_fsname.attr,
356 	&gfs2_attr_uuid.attr,
357 	&gfs2_attr_freeze.attr,
358 	&gfs2_attr_withdraw.attr,
359 	&gfs2_attr_statfs_sync.attr,
360 	&gfs2_attr_quota_sync.attr,
361 	&gfs2_attr_quota_refresh_user.attr,
362 	&gfs2_attr_quota_refresh_group.attr,
363 	&gfs2_attr_demote_rq.attr,
364 	&gfs2_attr_status.attr,
365 	NULL,
366 };
367 ATTRIBUTE_GROUPS(gfs2);
368 
369 static void gfs2_sbd_release(struct kobject *kobj)
370 {
371 	struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj);
372 
373 	complete(&sdp->sd_kobj_unregister);
374 }
375 
376 static struct kobj_type gfs2_ktype = {
377 	.release = gfs2_sbd_release,
378 	.default_groups = gfs2_groups,
379 	.sysfs_ops     = &gfs2_attr_ops,
380 };
381 
382 
383 /*
384  * lock_module. Originally from lock_dlm
385  */
386 
387 static ssize_t proto_name_show(struct gfs2_sbd *sdp, char *buf)
388 {
389 	const struct lm_lockops *ops = sdp->sd_lockstruct.ls_ops;
390 	return sprintf(buf, "%s\n", ops->lm_proto_name);
391 }
392 
393 static ssize_t block_show(struct gfs2_sbd *sdp, char *buf)
394 {
395 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
396 	ssize_t ret;
397 	int val = 0;
398 
399 	if (test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags))
400 		val = 1;
401 	ret = sprintf(buf, "%d\n", val);
402 	return ret;
403 }
404 
405 static ssize_t block_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
406 {
407 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
408 	int ret, val;
409 
410 	ret = kstrtoint(buf, 0, &val);
411 	if (ret)
412 		return ret;
413 
414 	if (val == 1)
415 		set_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
416 	else if (val == 0) {
417 		clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
418 		smp_mb__after_atomic();
419 		gfs2_glock_thaw(sdp);
420 	} else {
421 		return -EINVAL;
422 	}
423 	return len;
424 }
425 
426 static ssize_t wdack_show(struct gfs2_sbd *sdp, char *buf)
427 {
428 	int val = completion_done(&sdp->sd_wdack) ? 1 : 0;
429 
430 	return sprintf(buf, "%d\n", val);
431 }
432 
433 static ssize_t wdack_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
434 {
435 	int ret, val;
436 
437 	ret = kstrtoint(buf, 0, &val);
438 	if (ret)
439 		return ret;
440 
441 	if ((val == 1) &&
442 	    !strcmp(sdp->sd_lockstruct.ls_ops->lm_proto_name, "lock_dlm"))
443 		complete(&sdp->sd_wdack);
444 	else
445 		return -EINVAL;
446 	return len;
447 }
448 
449 static ssize_t lkfirst_show(struct gfs2_sbd *sdp, char *buf)
450 {
451 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
452 	return sprintf(buf, "%d\n", ls->ls_first);
453 }
454 
455 static ssize_t lkfirst_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
456 {
457 	unsigned first;
458 	int rv;
459 
460 	rv = sscanf(buf, "%u", &first);
461 	if (rv != 1 || first > 1)
462 		return -EINVAL;
463 	rv = wait_for_completion_killable(&sdp->sd_locking_init);
464 	if (rv)
465 		return rv;
466 	spin_lock(&sdp->sd_jindex_spin);
467 	rv = -EBUSY;
468 	if (test_bit(SDF_NOJOURNALID, &sdp->sd_flags) == 0)
469 		goto out;
470 	rv = -EINVAL;
471 	if (sdp->sd_args.ar_spectator)
472 		goto out;
473 	if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
474 		goto out;
475 	sdp->sd_lockstruct.ls_first = first;
476 	rv = 0;
477 out:
478         spin_unlock(&sdp->sd_jindex_spin);
479         return rv ? rv : len;
480 }
481 
482 static ssize_t first_done_show(struct gfs2_sbd *sdp, char *buf)
483 {
484 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
485 	return sprintf(buf, "%d\n", !!test_bit(DFL_FIRST_MOUNT_DONE, &ls->ls_recover_flags));
486 }
487 
488 int gfs2_recover_set(struct gfs2_sbd *sdp, unsigned jid)
489 {
490 	struct gfs2_jdesc *jd;
491 	int rv;
492 
493 	/* Wait for our primary journal to be initialized */
494 	wait_for_completion(&sdp->sd_journal_ready);
495 
496 	spin_lock(&sdp->sd_jindex_spin);
497 	rv = -EBUSY;
498 	/**
499 	 * If we're a spectator, we use journal0, but it's not really ours.
500 	 * So we need to wait for its recovery too. If we skip it we'd never
501 	 * queue work to the recovery workqueue, and so its completion would
502 	 * never clear the DFL_BLOCK_LOCKS flag, so all our locks would
503 	 * permanently stop working.
504 	 */
505 	if (!sdp->sd_jdesc)
506 		goto out;
507 	if (sdp->sd_jdesc->jd_jid == jid && !sdp->sd_args.ar_spectator)
508 		goto out;
509 	rv = -ENOENT;
510 	list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
511 		if (jd->jd_jid != jid && !sdp->sd_args.ar_spectator)
512 			continue;
513 		rv = gfs2_recover_journal(jd, false);
514 		break;
515 	}
516 out:
517 	spin_unlock(&sdp->sd_jindex_spin);
518 	return rv;
519 }
520 
521 static ssize_t recover_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
522 {
523 	unsigned jid;
524 	int rv;
525 
526 	rv = sscanf(buf, "%u", &jid);
527 	if (rv != 1)
528 		return -EINVAL;
529 
530 	if (test_bit(SDF_NORECOVERY, &sdp->sd_flags)) {
531 		rv = -ESHUTDOWN;
532 		goto out;
533 	}
534 
535 	rv = gfs2_recover_set(sdp, jid);
536 out:
537 	return rv ? rv : len;
538 }
539 
540 static ssize_t recover_done_show(struct gfs2_sbd *sdp, char *buf)
541 {
542 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
543 	return sprintf(buf, "%d\n", ls->ls_recover_jid_done);
544 }
545 
546 static ssize_t recover_status_show(struct gfs2_sbd *sdp, char *buf)
547 {
548 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
549 	return sprintf(buf, "%d\n", ls->ls_recover_jid_status);
550 }
551 
552 static ssize_t jid_show(struct gfs2_sbd *sdp, char *buf)
553 {
554 	return sprintf(buf, "%d\n", sdp->sd_lockstruct.ls_jid);
555 }
556 
557 static ssize_t jid_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
558 {
559         int jid;
560 	int rv;
561 
562 	rv = sscanf(buf, "%d", &jid);
563 	if (rv != 1)
564 		return -EINVAL;
565 	rv = wait_for_completion_killable(&sdp->sd_locking_init);
566 	if (rv)
567 		return rv;
568 	spin_lock(&sdp->sd_jindex_spin);
569 	rv = -EINVAL;
570 	if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
571 		goto out;
572 	rv = -EBUSY;
573 	if (test_bit(SDF_NOJOURNALID, &sdp->sd_flags) == 0)
574 		goto out;
575 	rv = 0;
576 	if (sdp->sd_args.ar_spectator && jid > 0)
577 		rv = jid = -EINVAL;
578 	sdp->sd_lockstruct.ls_jid = jid;
579 	clear_bit(SDF_NOJOURNALID, &sdp->sd_flags);
580 	smp_mb__after_atomic();
581 	wake_up_bit(&sdp->sd_flags, SDF_NOJOURNALID);
582 out:
583 	spin_unlock(&sdp->sd_jindex_spin);
584 	return rv ? rv : len;
585 }
586 
587 #define GDLM_ATTR(_name,_mode,_show,_store) \
588 static struct gfs2_attr gdlm_attr_##_name = __ATTR(_name,_mode,_show,_store)
589 
590 GDLM_ATTR(proto_name,		0444, proto_name_show,		NULL);
591 GDLM_ATTR(block,		0644, block_show,		block_store);
592 GDLM_ATTR(withdraw,		0644, wdack_show,		wdack_store);
593 GDLM_ATTR(jid,			0644, jid_show,			jid_store);
594 GDLM_ATTR(first,		0644, lkfirst_show,		lkfirst_store);
595 GDLM_ATTR(first_done,		0444, first_done_show,		NULL);
596 GDLM_ATTR(recover,		0600, NULL,			recover_store);
597 GDLM_ATTR(recover_done,		0444, recover_done_show,	NULL);
598 GDLM_ATTR(recover_status,	0444, recover_status_show,	NULL);
599 
600 static struct attribute *lock_module_attrs[] = {
601 	&gdlm_attr_proto_name.attr,
602 	&gdlm_attr_block.attr,
603 	&gdlm_attr_withdraw.attr,
604 	&gdlm_attr_jid.attr,
605 	&gdlm_attr_first.attr,
606 	&gdlm_attr_first_done.attr,
607 	&gdlm_attr_recover.attr,
608 	&gdlm_attr_recover_done.attr,
609 	&gdlm_attr_recover_status.attr,
610 	NULL,
611 };
612 
613 /*
614  * get and set struct gfs2_tune fields
615  */
616 
617 static ssize_t quota_scale_show(struct gfs2_sbd *sdp, char *buf)
618 {
619 	return snprintf(buf, PAGE_SIZE, "%u %u\n",
620 			sdp->sd_tune.gt_quota_scale_num,
621 			sdp->sd_tune.gt_quota_scale_den);
622 }
623 
624 static ssize_t quota_scale_store(struct gfs2_sbd *sdp, const char *buf,
625 				 size_t len)
626 {
627 	struct gfs2_tune *gt = &sdp->sd_tune;
628 	unsigned int x, y;
629 
630 	if (!capable(CAP_SYS_ADMIN))
631 		return -EPERM;
632 
633 	if (sscanf(buf, "%u %u", &x, &y) != 2 || !y)
634 		return -EINVAL;
635 
636 	spin_lock(&gt->gt_spin);
637 	gt->gt_quota_scale_num = x;
638 	gt->gt_quota_scale_den = y;
639 	spin_unlock(&gt->gt_spin);
640 	return len;
641 }
642 
643 static ssize_t tune_set(struct gfs2_sbd *sdp, unsigned int *field,
644 			int check_zero, const char *buf, size_t len)
645 {
646 	struct gfs2_tune *gt = &sdp->sd_tune;
647 	unsigned int x;
648 	int error;
649 
650 	if (!capable(CAP_SYS_ADMIN))
651 		return -EPERM;
652 
653 	error = kstrtouint(buf, 0, &x);
654 	if (error)
655 		return error;
656 
657 	if (check_zero && !x)
658 		return -EINVAL;
659 
660 	spin_lock(&gt->gt_spin);
661 	*field = x;
662 	spin_unlock(&gt->gt_spin);
663 	return len;
664 }
665 
666 #define TUNE_ATTR_3(name, show, store)                                        \
667 static struct gfs2_attr tune_attr_##name = __ATTR(name, 0644, show, store)
668 
669 #define TUNE_ATTR_2(name, store)                                              \
670 static ssize_t name##_show(struct gfs2_sbd *sdp, char *buf)                   \
671 {                                                                             \
672 	return snprintf(buf, PAGE_SIZE, "%u\n", sdp->sd_tune.gt_##name);      \
673 }                                                                             \
674 TUNE_ATTR_3(name, name##_show, store)
675 
676 #define TUNE_ATTR(name, check_zero)                                           \
677 static ssize_t name##_store(struct gfs2_sbd *sdp, const char *buf, size_t len)\
678 {                                                                             \
679 	return tune_set(sdp, &sdp->sd_tune.gt_##name, check_zero, buf, len);  \
680 }                                                                             \
681 TUNE_ATTR_2(name, name##_store)
682 
683 TUNE_ATTR(quota_warn_period, 0);
684 TUNE_ATTR(quota_quantum, 0);
685 TUNE_ATTR(max_readahead, 0);
686 TUNE_ATTR(complain_secs, 0);
687 TUNE_ATTR(statfs_slow, 0);
688 TUNE_ATTR(new_files_jdata, 0);
689 TUNE_ATTR(statfs_quantum, 1);
690 TUNE_ATTR_3(quota_scale, quota_scale_show, quota_scale_store);
691 
692 static struct attribute *tune_attrs[] = {
693 	&tune_attr_quota_warn_period.attr,
694 	&tune_attr_quota_quantum.attr,
695 	&tune_attr_max_readahead.attr,
696 	&tune_attr_complain_secs.attr,
697 	&tune_attr_statfs_slow.attr,
698 	&tune_attr_statfs_quantum.attr,
699 	&tune_attr_quota_scale.attr,
700 	&tune_attr_new_files_jdata.attr,
701 	NULL,
702 };
703 
704 static const struct attribute_group tune_group = {
705 	.name = "tune",
706 	.attrs = tune_attrs,
707 };
708 
709 static const struct attribute_group lock_module_group = {
710 	.name = "lock_module",
711 	.attrs = lock_module_attrs,
712 };
713 
714 int gfs2_sys_fs_add(struct gfs2_sbd *sdp)
715 {
716 	struct super_block *sb = sdp->sd_vfs;
717 	int error;
718 	char ro[20];
719 	char spectator[20];
720 	char *envp[] = { ro, spectator, NULL };
721 
722 	sprintf(ro, "RDONLY=%d", sb_rdonly(sb));
723 	sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);
724 
725 	init_completion(&sdp->sd_kobj_unregister);
726 	sdp->sd_kobj.kset = gfs2_kset;
727 	error = kobject_init_and_add(&sdp->sd_kobj, &gfs2_ktype, NULL,
728 				     "%s", sdp->sd_table_name);
729 	if (error)
730 		goto fail_reg;
731 
732 	error = sysfs_create_group(&sdp->sd_kobj, &tune_group);
733 	if (error)
734 		goto fail_reg;
735 
736 	error = sysfs_create_group(&sdp->sd_kobj, &lock_module_group);
737 	if (error)
738 		goto fail_tune;
739 
740 	error = sysfs_create_link(&sdp->sd_kobj,
741 				  &disk_to_dev(sb->s_bdev->bd_disk)->kobj,
742 				  "device");
743 	if (error)
744 		goto fail_lock_module;
745 
746 	kobject_uevent_env(&sdp->sd_kobj, KOBJ_ADD, envp);
747 	return 0;
748 
749 fail_lock_module:
750 	sysfs_remove_group(&sdp->sd_kobj, &lock_module_group);
751 fail_tune:
752 	sysfs_remove_group(&sdp->sd_kobj, &tune_group);
753 fail_reg:
754 	fs_err(sdp, "error %d adding sysfs files\n", error);
755 	kobject_put(&sdp->sd_kobj);
756 	wait_for_completion(&sdp->sd_kobj_unregister);
757 	sb->s_fs_info = NULL;
758 	return error;
759 }
760 
761 void gfs2_sys_fs_del(struct gfs2_sbd *sdp)
762 {
763 	sysfs_remove_link(&sdp->sd_kobj, "device");
764 	sysfs_remove_group(&sdp->sd_kobj, &tune_group);
765 	sysfs_remove_group(&sdp->sd_kobj, &lock_module_group);
766 	kobject_put(&sdp->sd_kobj);
767 	wait_for_completion(&sdp->sd_kobj_unregister);
768 }
769 
770 static int gfs2_uevent(struct kobject *kobj, struct kobj_uevent_env *env)
771 {
772 	struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj);
773 	struct super_block *s = sdp->sd_vfs;
774 
775 	add_uevent_var(env, "LOCKTABLE=%s", sdp->sd_table_name);
776 	add_uevent_var(env, "LOCKPROTO=%s", sdp->sd_proto_name);
777 	if (!test_bit(SDF_NOJOURNALID, &sdp->sd_flags))
778 		add_uevent_var(env, "JOURNALID=%d", sdp->sd_lockstruct.ls_jid);
779 	if (!uuid_is_null(&s->s_uuid))
780 		add_uevent_var(env, "UUID=%pUB", &s->s_uuid);
781 	return 0;
782 }
783 
784 static const struct kset_uevent_ops gfs2_uevent_ops = {
785 	.uevent = gfs2_uevent,
786 };
787 
788 int gfs2_sys_init(void)
789 {
790 	gfs2_kset = kset_create_and_add("gfs2", &gfs2_uevent_ops, fs_kobj);
791 	if (!gfs2_kset)
792 		return -ENOMEM;
793 	return 0;
794 }
795 
796 void gfs2_sys_uninit(void)
797 {
798 	kset_unregister(gfs2_kset);
799 }
800 
801