Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
[cascardo/linux.git] / fs / gfs2 / sys.c
1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
4  *
5  * This copyrighted material is made available to anyone wishing to use,
6  * modify, copy, or redistribute it subject to the terms and conditions
7  * of the GNU General Public License version 2.
8  */
9
10 #include <linux/sched.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 <asm/uaccess.h>
17 #include <linux/gfs2_ondisk.h>
18 #include <linux/genhd.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 fsname_show(struct gfs2_sbd *sdp, char *buf)
67 {
68         return snprintf(buf, PAGE_SIZE, "%s\n", sdp->sd_fsname);
69 }
70
71 static int gfs2_uuid_valid(const u8 *uuid)
72 {
73         int i;
74
75         for (i = 0; i < 16; i++) {
76                 if (uuid[i])
77                         return 1;
78         }
79         return 0;
80 }
81
82 static ssize_t uuid_show(struct gfs2_sbd *sdp, char *buf)
83 {
84         struct super_block *s = sdp->sd_vfs;
85         const u8 *uuid = s->s_uuid;
86         buf[0] = '\0';
87         if (!gfs2_uuid_valid(uuid))
88                 return 0;
89         return snprintf(buf, PAGE_SIZE, "%pUB\n", uuid);
90 }
91
92 static ssize_t freeze_show(struct gfs2_sbd *sdp, char *buf)
93 {
94         unsigned int count;
95
96         mutex_lock(&sdp->sd_freeze_lock);
97         count = sdp->sd_freeze_count;
98         mutex_unlock(&sdp->sd_freeze_lock);
99
100         return snprintf(buf, PAGE_SIZE, "%u\n", count);
101 }
102
103 static ssize_t freeze_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
104 {
105         ssize_t ret = len;
106         int error = 0;
107         int n = simple_strtol(buf, NULL, 0);
108
109         if (!capable(CAP_SYS_ADMIN))
110                 return -EACCES;
111
112         switch (n) {
113         case 0:
114                 gfs2_unfreeze_fs(sdp);
115                 break;
116         case 1:
117                 error = gfs2_freeze_fs(sdp);
118                 break;
119         default:
120                 ret = -EINVAL;
121         }
122
123         if (error)
124                 fs_warn(sdp, "freeze %d error %d", n, error);
125
126         return ret;
127 }
128
129 static ssize_t withdraw_show(struct gfs2_sbd *sdp, char *buf)
130 {
131         unsigned int b = test_bit(SDF_SHUTDOWN, &sdp->sd_flags);
132         return snprintf(buf, PAGE_SIZE, "%u\n", b);
133 }
134
135 static ssize_t withdraw_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
136 {
137         if (!capable(CAP_SYS_ADMIN))
138                 return -EACCES;
139
140         if (simple_strtol(buf, NULL, 0) != 1)
141                 return -EINVAL;
142
143         gfs2_lm_withdraw(sdp,
144                 "GFS2: fsid=%s: withdrawing from cluster at user's request\n",
145                 sdp->sd_fsname);
146         return len;
147 }
148
149 static ssize_t statfs_sync_store(struct gfs2_sbd *sdp, const char *buf,
150                                  size_t len)
151 {
152         if (!capable(CAP_SYS_ADMIN))
153                 return -EACCES;
154
155         if (simple_strtol(buf, NULL, 0) != 1)
156                 return -EINVAL;
157
158         gfs2_statfs_sync(sdp->sd_vfs, 0);
159         return len;
160 }
161
162 static ssize_t quota_sync_store(struct gfs2_sbd *sdp, const char *buf,
163                                 size_t len)
164 {
165         if (!capable(CAP_SYS_ADMIN))
166                 return -EACCES;
167
168         if (simple_strtol(buf, NULL, 0) != 1)
169                 return -EINVAL;
170
171         gfs2_quota_sync(sdp->sd_vfs, 0, 1);
172         return len;
173 }
174
175 static ssize_t quota_refresh_user_store(struct gfs2_sbd *sdp, const char *buf,
176                                         size_t len)
177 {
178         int error;
179         u32 id;
180
181         if (!capable(CAP_SYS_ADMIN))
182                 return -EACCES;
183
184         id = simple_strtoul(buf, NULL, 0);
185
186         error = gfs2_quota_refresh(sdp, 1, id);
187         return error ? error : len;
188 }
189
190 static ssize_t quota_refresh_group_store(struct gfs2_sbd *sdp, const char *buf,
191                                          size_t len)
192 {
193         int error;
194         u32 id;
195
196         if (!capable(CAP_SYS_ADMIN))
197                 return -EACCES;
198
199         id = simple_strtoul(buf, NULL, 0);
200
201         error = gfs2_quota_refresh(sdp, 0, id);
202         return error ? error : len;
203 }
204
205 static ssize_t demote_rq_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
206 {
207         struct gfs2_glock *gl;
208         const struct gfs2_glock_operations *glops;
209         unsigned int glmode;
210         unsigned int gltype;
211         unsigned long long glnum;
212         char mode[16];
213         int rv;
214
215         if (!capable(CAP_SYS_ADMIN))
216                 return -EACCES;
217
218         rv = sscanf(buf, "%u:%llu %15s", &gltype, &glnum,
219                     mode);
220         if (rv != 3)
221                 return -EINVAL;
222
223         if (strcmp(mode, "EX") == 0)
224                 glmode = LM_ST_UNLOCKED;
225         else if ((strcmp(mode, "CW") == 0) || (strcmp(mode, "DF") == 0))
226                 glmode = LM_ST_DEFERRED;
227         else if ((strcmp(mode, "PR") == 0) || (strcmp(mode, "SH") == 0))
228                 glmode = LM_ST_SHARED;
229         else
230                 return -EINVAL;
231
232         if (gltype > LM_TYPE_JOURNAL)
233                 return -EINVAL;
234         if (gltype == LM_TYPE_NONDISK && glnum == GFS2_TRANS_LOCK)
235                 glops = &gfs2_trans_glops;
236         else
237                 glops = gfs2_glops_list[gltype];
238         if (glops == NULL)
239                 return -EINVAL;
240         if (!test_and_set_bit(SDF_DEMOTE, &sdp->sd_flags))
241                 fs_info(sdp, "demote interface used\n");
242         rv = gfs2_glock_get(sdp, glnum, glops, 0, &gl);
243         if (rv)
244                 return rv;
245         gfs2_glock_cb(gl, glmode);
246         gfs2_glock_put(gl);
247         return len;
248 }
249
250
251 #define GFS2_ATTR(name, mode, show, store) \
252 static struct gfs2_attr gfs2_attr_##name = __ATTR(name, mode, show, store)
253
254 GFS2_ATTR(id,                  0444, id_show,       NULL);
255 GFS2_ATTR(fsname,              0444, fsname_show,   NULL);
256 GFS2_ATTR(uuid,                0444, uuid_show,     NULL);
257 GFS2_ATTR(freeze,              0644, freeze_show,   freeze_store);
258 GFS2_ATTR(withdraw,            0644, withdraw_show, withdraw_store);
259 GFS2_ATTR(statfs_sync,         0200, NULL,          statfs_sync_store);
260 GFS2_ATTR(quota_sync,          0200, NULL,          quota_sync_store);
261 GFS2_ATTR(quota_refresh_user,  0200, NULL,          quota_refresh_user_store);
262 GFS2_ATTR(quota_refresh_group, 0200, NULL,          quota_refresh_group_store);
263 GFS2_ATTR(demote_rq,           0200, NULL,          demote_rq_store);
264
265 static struct attribute *gfs2_attrs[] = {
266         &gfs2_attr_id.attr,
267         &gfs2_attr_fsname.attr,
268         &gfs2_attr_uuid.attr,
269         &gfs2_attr_freeze.attr,
270         &gfs2_attr_withdraw.attr,
271         &gfs2_attr_statfs_sync.attr,
272         &gfs2_attr_quota_sync.attr,
273         &gfs2_attr_quota_refresh_user.attr,
274         &gfs2_attr_quota_refresh_group.attr,
275         &gfs2_attr_demote_rq.attr,
276         NULL,
277 };
278
279 static struct kobj_type gfs2_ktype = {
280         .default_attrs = gfs2_attrs,
281         .sysfs_ops     = &gfs2_attr_ops,
282 };
283
284
285 /*
286  * lock_module. Originally from lock_dlm
287  */
288
289 static ssize_t proto_name_show(struct gfs2_sbd *sdp, char *buf)
290 {
291         const struct lm_lockops *ops = sdp->sd_lockstruct.ls_ops;
292         return sprintf(buf, "%s\n", ops->lm_proto_name);
293 }
294
295 static ssize_t block_show(struct gfs2_sbd *sdp, char *buf)
296 {
297         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
298         ssize_t ret;
299         int val = 0;
300
301         if (test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags))
302                 val = 1;
303         ret = sprintf(buf, "%d\n", val);
304         return ret;
305 }
306
307 static ssize_t block_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
308 {
309         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
310         ssize_t ret = len;
311         int val;
312
313         val = simple_strtol(buf, NULL, 0);
314
315         if (val == 1)
316                 set_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
317         else if (val == 0) {
318                 clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
319                 smp_mb__after_clear_bit();
320                 gfs2_glock_thaw(sdp);
321         } else {
322                 ret = -EINVAL;
323         }
324         return ret;
325 }
326
327 static ssize_t lkfirst_show(struct gfs2_sbd *sdp, char *buf)
328 {
329         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
330         return sprintf(buf, "%d\n", ls->ls_first);
331 }
332
333 static ssize_t lkfirst_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
334 {
335         unsigned first;
336         int rv;
337
338         rv = sscanf(buf, "%u", &first);
339         if (rv != 1 || first > 1)
340                 return -EINVAL;
341         rv = wait_for_completion_killable(&sdp->sd_locking_init);
342         if (rv)
343                 return rv;
344         spin_lock(&sdp->sd_jindex_spin);
345         rv = -EBUSY;
346         if (test_bit(SDF_NOJOURNALID, &sdp->sd_flags) == 0)
347                 goto out;
348         rv = -EINVAL;
349         if (sdp->sd_args.ar_spectator)
350                 goto out;
351         if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
352                 goto out;
353         sdp->sd_lockstruct.ls_first = first;
354         rv = 0;
355 out:
356         spin_unlock(&sdp->sd_jindex_spin);
357         return rv ? rv : len;
358 }
359
360 static ssize_t first_done_show(struct gfs2_sbd *sdp, char *buf)
361 {
362         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
363         return sprintf(buf, "%d\n", !!test_bit(DFL_FIRST_MOUNT_DONE, &ls->ls_recover_flags));
364 }
365
366 int gfs2_recover_set(struct gfs2_sbd *sdp, unsigned jid)
367 {
368         struct gfs2_jdesc *jd;
369         int rv;
370
371         rv = -ESHUTDOWN;
372         spin_lock(&sdp->sd_jindex_spin);
373         if (test_bit(SDF_NORECOVERY, &sdp->sd_flags))
374                 goto out;
375         rv = -EBUSY;
376         if (sdp->sd_jdesc->jd_jid == jid)
377                 goto out;
378         rv = -ENOENT;
379         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
380                 if (jd->jd_jid != jid)
381                         continue;
382                 rv = gfs2_recover_journal(jd, false);
383                 break;
384         }
385 out:
386         spin_unlock(&sdp->sd_jindex_spin);
387         return rv;
388 }
389
390 static ssize_t recover_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
391 {
392         unsigned jid;
393         int rv;
394
395         rv = sscanf(buf, "%u", &jid);
396         if (rv != 1)
397                 return -EINVAL;
398
399         rv = gfs2_recover_set(sdp, jid);
400
401         return rv ? rv : len;
402 }
403
404 static ssize_t recover_done_show(struct gfs2_sbd *sdp, char *buf)
405 {
406         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
407         return sprintf(buf, "%d\n", ls->ls_recover_jid_done);
408 }
409
410 static ssize_t recover_status_show(struct gfs2_sbd *sdp, char *buf)
411 {
412         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
413         return sprintf(buf, "%d\n", ls->ls_recover_jid_status);
414 }
415
416 static ssize_t jid_show(struct gfs2_sbd *sdp, char *buf)
417 {
418         return sprintf(buf, "%d\n", sdp->sd_lockstruct.ls_jid);
419 }
420
421 static ssize_t jid_store(struct gfs2_sbd *sdp, const char *buf, size_t len)
422 {
423         int jid;
424         int rv;
425
426         rv = sscanf(buf, "%d", &jid);
427         if (rv != 1)
428                 return -EINVAL;
429         rv = wait_for_completion_killable(&sdp->sd_locking_init);
430         if (rv)
431                 return rv;
432         spin_lock(&sdp->sd_jindex_spin);
433         rv = -EINVAL;
434         if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
435                 goto out;
436         rv = -EBUSY;
437         if (test_bit(SDF_NOJOURNALID, &sdp->sd_flags) == 0)
438                 goto out;
439         rv = 0;
440         if (sdp->sd_args.ar_spectator && jid > 0)
441                 rv = jid = -EINVAL;
442         sdp->sd_lockstruct.ls_jid = jid;
443         clear_bit(SDF_NOJOURNALID, &sdp->sd_flags);
444         smp_mb__after_clear_bit();
445         wake_up_bit(&sdp->sd_flags, SDF_NOJOURNALID);
446 out:
447         spin_unlock(&sdp->sd_jindex_spin);
448         return rv ? rv : len;
449 }
450
451 #define GDLM_ATTR(_name,_mode,_show,_store) \
452 static struct gfs2_attr gdlm_attr_##_name = __ATTR(_name,_mode,_show,_store)
453
454 GDLM_ATTR(proto_name,           0444, proto_name_show,          NULL);
455 GDLM_ATTR(block,                0644, block_show,               block_store);
456 GDLM_ATTR(withdraw,             0644, withdraw_show,            withdraw_store);
457 GDLM_ATTR(jid,                  0644, jid_show,                 jid_store);
458 GDLM_ATTR(first,                0644, lkfirst_show,             lkfirst_store);
459 GDLM_ATTR(first_done,           0444, first_done_show,          NULL);
460 GDLM_ATTR(recover,              0600, NULL,                     recover_store);
461 GDLM_ATTR(recover_done,         0444, recover_done_show,        NULL);
462 GDLM_ATTR(recover_status,       0444, recover_status_show,      NULL);
463
464 static struct attribute *lock_module_attrs[] = {
465         &gdlm_attr_proto_name.attr,
466         &gdlm_attr_block.attr,
467         &gdlm_attr_withdraw.attr,
468         &gdlm_attr_jid.attr,
469         &gdlm_attr_first.attr,
470         &gdlm_attr_first_done.attr,
471         &gdlm_attr_recover.attr,
472         &gdlm_attr_recover_done.attr,
473         &gdlm_attr_recover_status.attr,
474         NULL,
475 };
476
477 /*
478  * get and set struct gfs2_tune fields
479  */
480
481 static ssize_t quota_scale_show(struct gfs2_sbd *sdp, char *buf)
482 {
483         return snprintf(buf, PAGE_SIZE, "%u %u\n",
484                         sdp->sd_tune.gt_quota_scale_num,
485                         sdp->sd_tune.gt_quota_scale_den);
486 }
487
488 static ssize_t quota_scale_store(struct gfs2_sbd *sdp, const char *buf,
489                                  size_t len)
490 {
491         struct gfs2_tune *gt = &sdp->sd_tune;
492         unsigned int x, y;
493
494         if (!capable(CAP_SYS_ADMIN))
495                 return -EACCES;
496
497         if (sscanf(buf, "%u %u", &x, &y) != 2 || !y)
498                 return -EINVAL;
499
500         spin_lock(&gt->gt_spin);
501         gt->gt_quota_scale_num = x;
502         gt->gt_quota_scale_den = y;
503         spin_unlock(&gt->gt_spin);
504         return len;
505 }
506
507 static ssize_t tune_set(struct gfs2_sbd *sdp, unsigned int *field,
508                         int check_zero, const char *buf, size_t len)
509 {
510         struct gfs2_tune *gt = &sdp->sd_tune;
511         unsigned int x;
512
513         if (!capable(CAP_SYS_ADMIN))
514                 return -EACCES;
515
516         x = simple_strtoul(buf, NULL, 0);
517
518         if (check_zero && !x)
519                 return -EINVAL;
520
521         spin_lock(&gt->gt_spin);
522         *field = x;
523         spin_unlock(&gt->gt_spin);
524         return len;
525 }
526
527 #define TUNE_ATTR_3(name, show, store)                                        \
528 static struct gfs2_attr tune_attr_##name = __ATTR(name, 0644, show, store)
529
530 #define TUNE_ATTR_2(name, store)                                              \
531 static ssize_t name##_show(struct gfs2_sbd *sdp, char *buf)                   \
532 {                                                                             \
533         return snprintf(buf, PAGE_SIZE, "%u\n", sdp->sd_tune.gt_##name);      \
534 }                                                                             \
535 TUNE_ATTR_3(name, name##_show, store)
536
537 #define TUNE_ATTR(name, check_zero)                                           \
538 static ssize_t name##_store(struct gfs2_sbd *sdp, const char *buf, size_t len)\
539 {                                                                             \
540         return tune_set(sdp, &sdp->sd_tune.gt_##name, check_zero, buf, len);  \
541 }                                                                             \
542 TUNE_ATTR_2(name, name##_store)
543
544 TUNE_ATTR(quota_warn_period, 0);
545 TUNE_ATTR(quota_quantum, 0);
546 TUNE_ATTR(max_readahead, 0);
547 TUNE_ATTR(complain_secs, 0);
548 TUNE_ATTR(statfs_slow, 0);
549 TUNE_ATTR(new_files_jdata, 0);
550 TUNE_ATTR(quota_simul_sync, 1);
551 TUNE_ATTR(statfs_quantum, 1);
552 TUNE_ATTR_3(quota_scale, quota_scale_show, quota_scale_store);
553
554 static struct attribute *tune_attrs[] = {
555         &tune_attr_quota_warn_period.attr,
556         &tune_attr_quota_quantum.attr,
557         &tune_attr_max_readahead.attr,
558         &tune_attr_complain_secs.attr,
559         &tune_attr_statfs_slow.attr,
560         &tune_attr_quota_simul_sync.attr,
561         &tune_attr_statfs_quantum.attr,
562         &tune_attr_quota_scale.attr,
563         &tune_attr_new_files_jdata.attr,
564         NULL,
565 };
566
567 static struct attribute_group tune_group = {
568         .name = "tune",
569         .attrs = tune_attrs,
570 };
571
572 static struct attribute_group lock_module_group = {
573         .name = "lock_module",
574         .attrs = lock_module_attrs,
575 };
576
577 int gfs2_sys_fs_add(struct gfs2_sbd *sdp)
578 {
579         struct super_block *sb = sdp->sd_vfs;
580         int error;
581         char ro[20];
582         char spectator[20];
583         char *envp[] = { ro, spectator, NULL };
584
585         sprintf(ro, "RDONLY=%d", (sb->s_flags & MS_RDONLY) ? 1 : 0);
586         sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);
587
588         sdp->sd_kobj.kset = gfs2_kset;
589         error = kobject_init_and_add(&sdp->sd_kobj, &gfs2_ktype, NULL,
590                                      "%s", sdp->sd_table_name);
591         if (error)
592                 goto fail;
593
594         error = sysfs_create_group(&sdp->sd_kobj, &tune_group);
595         if (error)
596                 goto fail_reg;
597
598         error = sysfs_create_group(&sdp->sd_kobj, &lock_module_group);
599         if (error)
600                 goto fail_tune;
601
602         error = sysfs_create_link(&sdp->sd_kobj,
603                                   &disk_to_dev(sb->s_bdev->bd_disk)->kobj,
604                                   "device");
605         if (error)
606                 goto fail_lock_module;
607
608         kobject_uevent_env(&sdp->sd_kobj, KOBJ_ADD, envp);
609         return 0;
610
611 fail_lock_module:
612         sysfs_remove_group(&sdp->sd_kobj, &lock_module_group);
613 fail_tune:
614         sysfs_remove_group(&sdp->sd_kobj, &tune_group);
615 fail_reg:
616         kobject_put(&sdp->sd_kobj);
617 fail:
618         fs_err(sdp, "error %d adding sysfs files", error);
619         return error;
620 }
621
622 void gfs2_sys_fs_del(struct gfs2_sbd *sdp)
623 {
624         sysfs_remove_link(&sdp->sd_kobj, "device");
625         sysfs_remove_group(&sdp->sd_kobj, &tune_group);
626         sysfs_remove_group(&sdp->sd_kobj, &lock_module_group);
627         kobject_put(&sdp->sd_kobj);
628 }
629
630 static int gfs2_uevent(struct kset *kset, struct kobject *kobj,
631                        struct kobj_uevent_env *env)
632 {
633         struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj);
634         struct super_block *s = sdp->sd_vfs;
635         const u8 *uuid = s->s_uuid;
636
637         add_uevent_var(env, "LOCKTABLE=%s", sdp->sd_table_name);
638         add_uevent_var(env, "LOCKPROTO=%s", sdp->sd_proto_name);
639         if (!test_bit(SDF_NOJOURNALID, &sdp->sd_flags))
640                 add_uevent_var(env, "JOURNALID=%d", sdp->sd_lockstruct.ls_jid);
641         if (gfs2_uuid_valid(uuid))
642                 add_uevent_var(env, "UUID=%pUB", uuid);
643         return 0;
644 }
645
646 static const struct kset_uevent_ops gfs2_uevent_ops = {
647         .uevent = gfs2_uevent,
648 };
649
650 int gfs2_sys_init(void)
651 {
652         gfs2_kset = kset_create_and_add("gfs2", &gfs2_uevent_ops, fs_kobj);
653         if (!gfs2_kset)
654                 return -ENOMEM;
655         return 0;
656 }
657
658 void gfs2_sys_uninit(void)
659 {
660         kset_unregister(gfs2_kset);
661 }
662