RISC-V: Fix a race condition during kernel stack overflow
[platform/kernel/linux-starfive.git] / fs / gfs2 / sys.c
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