1/*
  2 * Copyright (C) 2007 Oracle.  All rights reserved.
  3 *
  4 * This program is free software; you can redistribute it and/or
  5 * modify it under the terms of the GNU General Public
  6 * License v2 as published by the Free Software Foundation.
  7 *
  8 * This program is distributed in the hope that it will be useful,
  9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 11 * General Public License for more details.
 12 *
 13 * You should have received a copy of the GNU General Public
 14 * License along with this program; if not, write to the
 15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 16 * Boston, MA 021110-1307, USA.
 17 */
 18
 19#include <linux/sched.h>
 20#include <linux/slab.h>
 21#include <linux/spinlock.h>
 22#include <linux/completion.h>
 23#include <linux/buffer_head.h>
 24#include <linux/kobject.h>
 25#include <linux/bug.h>
 26#include <linux/genhd.h>
 27#include <linux/debugfs.h>
 28
 29#include "ctree.h"
 30#include "disk-io.h"
 31#include "transaction.h"
 32#include "sysfs.h"
 33#include "volumes.h"
 34
 35static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
 36static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
 37
 38static u64 get_features(struct btrfs_fs_info *fs_info,
 39			enum btrfs_feature_set set)
 40{
 41	struct btrfs_super_block *disk_super = fs_info->super_copy;
 42	if (set == FEAT_COMPAT)
 43		return btrfs_super_compat_flags(disk_super);
 44	else if (set == FEAT_COMPAT_RO)
 45		return btrfs_super_compat_ro_flags(disk_super);
 46	else
 47		return btrfs_super_incompat_flags(disk_super);
 48}
 49
 50static void set_features(struct btrfs_fs_info *fs_info,
 51			 enum btrfs_feature_set set, u64 features)
 52{
 53	struct btrfs_super_block *disk_super = fs_info->super_copy;
 54	if (set == FEAT_COMPAT)
 55		btrfs_set_super_compat_flags(disk_super, features);
 56	else if (set == FEAT_COMPAT_RO)
 57		btrfs_set_super_compat_ro_flags(disk_super, features);
 58	else
 59		btrfs_set_super_incompat_flags(disk_super, features);
 60}
 61
 62static int can_modify_feature(struct btrfs_feature_attr *fa)
 63{
 64	int val = 0;
 65	u64 set, clear;
 66	switch (fa->feature_set) {
 67	case FEAT_COMPAT:
 68		set = BTRFS_FEATURE_COMPAT_SAFE_SET;
 69		clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
 70		break;
 71	case FEAT_COMPAT_RO:
 72		set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
 73		clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
 74		break;
 75	case FEAT_INCOMPAT:
 76		set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
 77		clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 78		break;
 79	default:
 80		printk(KERN_WARNING "btrfs: sysfs: unknown feature set %d\n",
 81				fa->feature_set);
 82		return 0;
 83	}
 84
 85	if (set & fa->feature_bit)
 86		val |= 1;
 87	if (clear & fa->feature_bit)
 88		val |= 2;
 89
 90	return val;
 91}
 92
 93static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
 94				       struct kobj_attribute *a, char *buf)
 95{
 96	int val = 0;
 97	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
 98	struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 99	if (fs_info) {
100		u64 features = get_features(fs_info, fa->feature_set);
101		if (features & fa->feature_bit)
102			val = 1;
103	} else
104		val = can_modify_feature(fa);
105
106	return snprintf(buf, PAGE_SIZE, "%d\n", val);
107}
108
109static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
110					struct kobj_attribute *a,
111					const char *buf, size_t count)
112{
113	struct btrfs_fs_info *fs_info;
114	struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
 
115	u64 features, set, clear;
116	unsigned long val;
117	int ret;
118
119	fs_info = to_fs_info(kobj);
120	if (!fs_info)
121		return -EPERM;
122
123	ret = kstrtoul(skip_spaces(buf), 0, &val);
124	if (ret)
125		return ret;
126
127	if (fa->feature_set == FEAT_COMPAT) {
128		set = BTRFS_FEATURE_COMPAT_SAFE_SET;
129		clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
130	} else if (fa->feature_set == FEAT_COMPAT_RO) {
131		set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
132		clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
133	} else {
134		set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
135		clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
136	}
137
138	features = get_features(fs_info, fa->feature_set);
139
140	/* Nothing to do */
141	if ((val && (features & fa->feature_bit)) ||
142	    (!val && !(features & fa->feature_bit)))
143		return count;
144
145	if ((val && !(set & fa->feature_bit)) ||
146	    (!val && !(clear & fa->feature_bit))) {
147		btrfs_info(fs_info,
148			"%sabling feature %s on mounted fs is not supported.",
149			val ? "En" : "Dis", fa->kobj_attr.attr.name);
150		return -EPERM;
151	}
152
153	btrfs_info(fs_info, "%s %s feature flag",
154		   val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
155
 
 
 
 
156	spin_lock(&fs_info->super_lock);
157	features = get_features(fs_info, fa->feature_set);
158	if (val)
159		features |= fa->feature_bit;
160	else
161		features &= ~fa->feature_bit;
162	set_features(fs_info, fa->feature_set, features);
163	spin_unlock(&fs_info->super_lock);
164
165	/*
166	 * We don't want to do full transaction commit from inside sysfs
167	 */
168	btrfs_set_pending(fs_info, COMMIT);
169	wake_up_process(fs_info->transaction_kthread);
170
171	return count;
172}
173
174static umode_t btrfs_feature_visible(struct kobject *kobj,
175				     struct attribute *attr, int unused)
176{
177	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
178	umode_t mode = attr->mode;
179
180	if (fs_info) {
181		struct btrfs_feature_attr *fa;
182		u64 features;
183
184		fa = attr_to_btrfs_feature_attr(attr);
185		features = get_features(fs_info, fa->feature_set);
186
187		if (can_modify_feature(fa))
188			mode |= S_IWUSR;
189		else if (!(features & fa->feature_bit))
190			mode = 0;
191	}
192
193	return mode;
194}
195
196BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF);
197BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
198BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
199BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
200BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA);
201BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
202BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
203BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
204BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
205BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
206
207static struct attribute *btrfs_supported_feature_attrs[] = {
208	BTRFS_FEAT_ATTR_PTR(mixed_backref),
209	BTRFS_FEAT_ATTR_PTR(default_subvol),
210	BTRFS_FEAT_ATTR_PTR(mixed_groups),
211	BTRFS_FEAT_ATTR_PTR(compress_lzo),
212	BTRFS_FEAT_ATTR_PTR(big_metadata),
213	BTRFS_FEAT_ATTR_PTR(extended_iref),
214	BTRFS_FEAT_ATTR_PTR(raid56),
215	BTRFS_FEAT_ATTR_PTR(skinny_metadata),
216	BTRFS_FEAT_ATTR_PTR(no_holes),
217	BTRFS_FEAT_ATTR_PTR(free_space_tree),
218	NULL
219};
220
221static const struct attribute_group btrfs_feature_attr_group = {
222	.name = "features",
223	.is_visible = btrfs_feature_visible,
224	.attrs = btrfs_supported_feature_attrs,
225};
226
227static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
228{
229	u64 val;
230	if (lock)
231		spin_lock(lock);
232	val = *value_ptr;
233	if (lock)
234		spin_unlock(lock);
235	return snprintf(buf, PAGE_SIZE, "%llu\n", val);
236}
237
238static ssize_t global_rsv_size_show(struct kobject *kobj,
239				    struct kobj_attribute *ka, char *buf)
240{
241	struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
242	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
243	return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
244}
245BTRFS_ATTR(global_rsv_size, global_rsv_size_show);
246
247static ssize_t global_rsv_reserved_show(struct kobject *kobj,
248					struct kobj_attribute *a, char *buf)
249{
250	struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
251	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
252	return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
253}
254BTRFS_ATTR(global_rsv_reserved, global_rsv_reserved_show);
255
256#define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
257#define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
258
259static ssize_t raid_bytes_show(struct kobject *kobj,
260			       struct kobj_attribute *attr, char *buf);
261BTRFS_RAID_ATTR(total_bytes, raid_bytes_show);
262BTRFS_RAID_ATTR(used_bytes, raid_bytes_show);
263
264static ssize_t raid_bytes_show(struct kobject *kobj,
265			       struct kobj_attribute *attr, char *buf)
266
267{
268	struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
269	struct btrfs_block_group_cache *block_group;
270	int index = to_raid_kobj(kobj)->raid_type;
271	u64 val = 0;
272
273	down_read(&sinfo->groups_sem);
274	list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
275		if (&attr->attr == BTRFS_RAID_ATTR_PTR(total_bytes))
276			val += block_group->key.offset;
277		else
278			val += btrfs_block_group_used(&block_group->item);
279	}
280	up_read(&sinfo->groups_sem);
281	return snprintf(buf, PAGE_SIZE, "%llu\n", val);
282}
283
284static struct attribute *raid_attributes[] = {
285	BTRFS_RAID_ATTR_PTR(total_bytes),
286	BTRFS_RAID_ATTR_PTR(used_bytes),
287	NULL
288};
289
290static void release_raid_kobj(struct kobject *kobj)
291{
292	kfree(to_raid_kobj(kobj));
293}
294
295struct kobj_type btrfs_raid_ktype = {
296	.sysfs_ops = &kobj_sysfs_ops,
297	.release = release_raid_kobj,
298	.default_attrs = raid_attributes,
299};
300
301#define SPACE_INFO_ATTR(field)						\
302static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,	\
303					     struct kobj_attribute *a,	\
304					     char *buf)			\
305{									\
306	struct btrfs_space_info *sinfo = to_space_info(kobj);		\
307	return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);	\
308}									\
309BTRFS_ATTR(field, btrfs_space_info_show_##field)
310
311static ssize_t btrfs_space_info_show_total_bytes_pinned(struct kobject *kobj,
312						       struct kobj_attribute *a,
313						       char *buf)
314{
315	struct btrfs_space_info *sinfo = to_space_info(kobj);
316	s64 val = percpu_counter_sum(&sinfo->total_bytes_pinned);
317	return snprintf(buf, PAGE_SIZE, "%lld\n", val);
318}
319
320SPACE_INFO_ATTR(flags);
321SPACE_INFO_ATTR(total_bytes);
322SPACE_INFO_ATTR(bytes_used);
323SPACE_INFO_ATTR(bytes_pinned);
324SPACE_INFO_ATTR(bytes_reserved);
325SPACE_INFO_ATTR(bytes_may_use);
326SPACE_INFO_ATTR(disk_used);
327SPACE_INFO_ATTR(disk_total);
328BTRFS_ATTR(total_bytes_pinned, btrfs_space_info_show_total_bytes_pinned);
329
330static struct attribute *space_info_attrs[] = {
331	BTRFS_ATTR_PTR(flags),
332	BTRFS_ATTR_PTR(total_bytes),
333	BTRFS_ATTR_PTR(bytes_used),
334	BTRFS_ATTR_PTR(bytes_pinned),
335	BTRFS_ATTR_PTR(bytes_reserved),
336	BTRFS_ATTR_PTR(bytes_may_use),
337	BTRFS_ATTR_PTR(disk_used),
338	BTRFS_ATTR_PTR(disk_total),
339	BTRFS_ATTR_PTR(total_bytes_pinned),
340	NULL,
341};
342
343static void space_info_release(struct kobject *kobj)
344{
345	struct btrfs_space_info *sinfo = to_space_info(kobj);
346	percpu_counter_destroy(&sinfo->total_bytes_pinned);
347	kfree(sinfo);
348}
349
350struct kobj_type space_info_ktype = {
351	.sysfs_ops = &kobj_sysfs_ops,
352	.release = space_info_release,
353	.default_attrs = space_info_attrs,
354};
355
356static const struct attribute *allocation_attrs[] = {
357	BTRFS_ATTR_PTR(global_rsv_reserved),
358	BTRFS_ATTR_PTR(global_rsv_size),
359	NULL,
360};
361
362static ssize_t btrfs_label_show(struct kobject *kobj,
363				struct kobj_attribute *a, char *buf)
364{
365	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
366	char *label = fs_info->super_copy->label;
367	return snprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label);
368}
369
370static ssize_t btrfs_label_store(struct kobject *kobj,
371				 struct kobj_attribute *a,
372				 const char *buf, size_t len)
373{
374	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
375	size_t p_len;
376
377	if (fs_info->sb->s_flags & MS_RDONLY)
378		return -EROFS;
379
380	/*
381	 * p_len is the len until the first occurrence of either
382	 * '\n' or '\0'
383	 */
384	p_len = strcspn(buf, "\n");
385
386	if (p_len >= BTRFS_LABEL_SIZE)
 
 
387		return -EINVAL;
 
388
389	spin_lock(&fs_info->super_lock);
390	memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
391	memcpy(fs_info->super_copy->label, buf, p_len);
392	spin_unlock(&fs_info->super_lock);
393
394	/*
395	 * We don't want to do full transaction commit from inside sysfs
396	 */
397	btrfs_set_pending(fs_info, COMMIT);
398	wake_up_process(fs_info->transaction_kthread);
399
400	return len;
401}
402BTRFS_ATTR_RW(label, btrfs_label_show, btrfs_label_store);
403
404static ssize_t btrfs_nodesize_show(struct kobject *kobj,
405				struct kobj_attribute *a, char *buf)
406{
407	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
408
409	return snprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize);
410}
411
412BTRFS_ATTR(nodesize, btrfs_nodesize_show);
 
 
 
413
414static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
415				struct kobj_attribute *a, char *buf)
416{
417	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
418
419	return snprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->sectorsize);
420}
 
421
422BTRFS_ATTR(sectorsize, btrfs_sectorsize_show);
423
424static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
425				struct kobj_attribute *a, char *buf)
426{
427	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
428
429	return snprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->sectorsize);
430}
431
432BTRFS_ATTR(clone_alignment, btrfs_clone_alignment_show);
433
434static const struct attribute *btrfs_attrs[] = {
435	BTRFS_ATTR_PTR(label),
436	BTRFS_ATTR_PTR(nodesize),
437	BTRFS_ATTR_PTR(sectorsize),
438	BTRFS_ATTR_PTR(clone_alignment),
439	NULL,
440};
441
442static void btrfs_release_fsid_kobj(struct kobject *kobj)
443{
444	struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
445
446	memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
447	complete(&fs_devs->kobj_unregister);
448}
449
450static struct kobj_type btrfs_ktype = {
451	.sysfs_ops	= &kobj_sysfs_ops,
452	.release	= btrfs_release_fsid_kobj,
 
453};
454
455static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
456{
457	if (kobj->ktype != &btrfs_ktype)
458		return NULL;
459	return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
460}
461
462static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
463{
464	if (kobj->ktype != &btrfs_ktype)
465		return NULL;
466	return to_fs_devs(kobj)->fs_info;
467}
468
469#define NUM_FEATURE_BITS 64
470static char btrfs_unknown_feature_names[3][NUM_FEATURE_BITS][13];
471static struct btrfs_feature_attr btrfs_feature_attrs[3][NUM_FEATURE_BITS];
472
473static const u64 supported_feature_masks[3] = {
474	[FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
475	[FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
476	[FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
477};
478
479static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
480{
481	int set;
482
483	for (set = 0; set < FEAT_MAX; set++) {
484		int i;
485		struct attribute *attrs[2];
486		struct attribute_group agroup = {
487			.name = "features",
488			.attrs = attrs,
489		};
490		u64 features = get_features(fs_info, set);
491		features &= ~supported_feature_masks[set];
492
493		if (!features)
494			continue;
495
496		attrs[1] = NULL;
497		for (i = 0; i < NUM_FEATURE_BITS; i++) {
498			struct btrfs_feature_attr *fa;
499
500			if (!(features & (1ULL << i)))
501				continue;
502
503			fa = &btrfs_feature_attrs[set][i];
504			attrs[0] = &fa->kobj_attr.attr;
505			if (add) {
506				int ret;
507				ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
508							&agroup);
509				if (ret)
510					return ret;
511			} else
512				sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
513						    &agroup);
514		}
515
516	}
517	return 0;
518}
519
520static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
521{
522	if (fs_devs->device_dir_kobj) {
523		kobject_del(fs_devs->device_dir_kobj);
524		kobject_put(fs_devs->device_dir_kobj);
525		fs_devs->device_dir_kobj = NULL;
526	}
527
528	if (fs_devs->fsid_kobj.state_initialized) {
529		kobject_del(&fs_devs->fsid_kobj);
530		kobject_put(&fs_devs->fsid_kobj);
531		wait_for_completion(&fs_devs->kobj_unregister);
532	}
533}
534
535/* when fs_devs is NULL it will remove all fsid kobject */
536void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
537{
538	struct list_head *fs_uuids = btrfs_get_fs_uuids();
539
540	if (fs_devs) {
541		__btrfs_sysfs_remove_fsid(fs_devs);
542		return;
543	}
544
545	list_for_each_entry(fs_devs, fs_uuids, list) {
546		__btrfs_sysfs_remove_fsid(fs_devs);
547	}
548}
549
550void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
551{
552	btrfs_reset_fs_info_ptr(fs_info);
553
554	if (fs_info->space_info_kobj) {
555		sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
556		kobject_del(fs_info->space_info_kobj);
557		kobject_put(fs_info->space_info_kobj);
558	}
 
 
559	addrm_unknown_feature_attrs(fs_info, false);
560	sysfs_remove_group(&fs_info->fs_devices->fsid_kobj, &btrfs_feature_attr_group);
561	sysfs_remove_files(&fs_info->fs_devices->fsid_kobj, btrfs_attrs);
562	btrfs_sysfs_rm_device_link(fs_info->fs_devices, NULL);
563}
564
565const char * const btrfs_feature_set_names[3] = {
566	[FEAT_COMPAT]	 = "compat",
567	[FEAT_COMPAT_RO] = "compat_ro",
568	[FEAT_INCOMPAT]	 = "incompat",
569};
570
571char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
572{
573	size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
574	int len = 0;
575	int i;
576	char *str;
577
578	str = kmalloc(bufsize, GFP_KERNEL);
579	if (!str)
580		return str;
581
582	for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
583		const char *name;
584
585		if (!(flags & (1ULL << i)))
586			continue;
587
588		name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
589		len += snprintf(str + len, bufsize - len, "%s%s",
590				len ? "," : "", name);
591	}
592
593	return str;
594}
595
596static void init_feature_attrs(void)
597{
598	struct btrfs_feature_attr *fa;
599	int set, i;
600
601	BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) !=
602		     ARRAY_SIZE(btrfs_feature_attrs));
603	BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) !=
604		     ARRAY_SIZE(btrfs_feature_attrs[0]));
605
606	memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
607	memset(btrfs_unknown_feature_names, 0,
608	       sizeof(btrfs_unknown_feature_names));
609
610	for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
611		struct btrfs_feature_attr *sfa;
612		struct attribute *a = btrfs_supported_feature_attrs[i];
613		int bit;
614		sfa = attr_to_btrfs_feature_attr(a);
615		bit = ilog2(sfa->feature_bit);
616		fa = &btrfs_feature_attrs[sfa->feature_set][bit];
617
618		fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
619	}
620
621	for (set = 0; set < FEAT_MAX; set++) {
622		for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
623			char *name = btrfs_unknown_feature_names[set][i];
624			fa = &btrfs_feature_attrs[set][i];
625
626			if (fa->kobj_attr.attr.name)
627				continue;
628
629			snprintf(name, 13, "%s:%u",
630				 btrfs_feature_set_names[set], i);
631
632			fa->kobj_attr.attr.name = name;
633			fa->kobj_attr.attr.mode = S_IRUGO;
634			fa->feature_set = set;
635			fa->feature_bit = 1ULL << i;
636		}
637	}
638}
639
640/* when one_device is NULL, it removes all device links */
641
642int btrfs_sysfs_rm_device_link(struct btrfs_fs_devices *fs_devices,
643		struct btrfs_device *one_device)
644{
645	struct hd_struct *disk;
646	struct kobject *disk_kobj;
647
648	if (!fs_devices->device_dir_kobj)
649		return -EINVAL;
650
651	if (one_device && one_device->bdev) {
652		disk = one_device->bdev->bd_part;
653		disk_kobj = &part_to_dev(disk)->kobj;
654
655		sysfs_remove_link(fs_devices->device_dir_kobj,
656						disk_kobj->name);
657	}
658
659	if (one_device)
660		return 0;
661
662	list_for_each_entry(one_device,
663			&fs_devices->devices, dev_list) {
664		if (!one_device->bdev)
665			continue;
666		disk = one_device->bdev->bd_part;
667		disk_kobj = &part_to_dev(disk)->kobj;
668
669		sysfs_remove_link(fs_devices->device_dir_kobj,
670						disk_kobj->name);
671	}
672
673	return 0;
674}
675
676int btrfs_sysfs_add_device(struct btrfs_fs_devices *fs_devs)
677{
678	if (!fs_devs->device_dir_kobj)
679		fs_devs->device_dir_kobj = kobject_create_and_add("devices",
680						&fs_devs->fsid_kobj);
681
682	if (!fs_devs->device_dir_kobj)
683		return -ENOMEM;
684
685	return 0;
686}
687
688int btrfs_sysfs_add_device_link(struct btrfs_fs_devices *fs_devices,
689				struct btrfs_device *one_device)
690{
691	int error = 0;
 
692	struct btrfs_device *dev;
693
 
 
 
 
 
694	list_for_each_entry(dev, &fs_devices->devices, dev_list) {
695		struct hd_struct *disk;
696		struct kobject *disk_kobj;
697
698		if (!dev->bdev)
699			continue;
700
701		if (one_device && one_device != dev)
702			continue;
703
704		disk = dev->bdev->bd_part;
705		disk_kobj = &part_to_dev(disk)->kobj;
706
707		error = sysfs_create_link(fs_devices->device_dir_kobj,
708					  disk_kobj, disk_kobj->name);
709		if (error)
710			break;
711	}
712
713	return error;
714}
715
716/* /sys/fs/btrfs/ entry */
717static struct kset *btrfs_kset;
718
719/* /sys/kernel/debug/btrfs */
720static struct dentry *btrfs_debugfs_root_dentry;
721
722/* Debugging tunables and exported data */
723u64 btrfs_debugfs_test;
724
725/*
726 * Can be called by the device discovery thread.
727 * And parent can be specified for seed device
728 */
729int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs,
730				struct kobject *parent)
731{
732	int error;
733
734	init_completion(&fs_devs->kobj_unregister);
735	fs_devs->fsid_kobj.kset = btrfs_kset;
736	error = kobject_init_and_add(&fs_devs->fsid_kobj,
737				&btrfs_ktype, parent, "%pU", fs_devs->fsid);
738	return error;
739}
740
741int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
742{
743	int error;
744	struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
745	struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
746
747	btrfs_set_fs_info_ptr(fs_info);
748
749	error = btrfs_sysfs_add_device_link(fs_devs, NULL);
 
750	if (error)
751		return error;
752
753	error = sysfs_create_files(fsid_kobj, btrfs_attrs);
 
754	if (error) {
755		btrfs_sysfs_rm_device_link(fs_devs, NULL);
756		return error;
757	}
758
759	error = sysfs_create_group(fsid_kobj,
760				   &btrfs_feature_attr_group);
761	if (error)
762		goto failure;
763
764	error = addrm_unknown_feature_attrs(fs_info, true);
765	if (error)
766		goto failure;
767
768	fs_info->space_info_kobj = kobject_create_and_add("allocation",
769						  fsid_kobj);
770	if (!fs_info->space_info_kobj) {
771		error = -ENOMEM;
772		goto failure;
773	}
774
775	error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
776	if (error)
777		goto failure;
778
779	return 0;
780failure:
781	btrfs_sysfs_remove_mounted(fs_info);
782	return error;
783}
784
785
786/*
787 * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
788 * values in superblock. Call after any changes to incompat/compat_ro flags
789 */
790void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
791		u64 bit, enum btrfs_feature_set set)
792{
793	struct btrfs_fs_devices *fs_devs;
794	struct kobject *fsid_kobj;
795	u64 features;
796	int ret;
797
798	if (!fs_info)
799		return;
800
801	features = get_features(fs_info, set);
802	ASSERT(bit & supported_feature_masks[set]);
803
804	fs_devs = fs_info->fs_devices;
805	fsid_kobj = &fs_devs->fsid_kobj;
806
807	if (!fsid_kobj->state_initialized)
808		return;
809
810	/*
811	 * FIXME: this is too heavy to update just one value, ideally we'd like
812	 * to use sysfs_update_group but some refactoring is needed first.
813	 */
814	sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
815	ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
816}
817
818static int btrfs_init_debugfs(void)
819{
820#ifdef CONFIG_DEBUG_FS
821	btrfs_debugfs_root_dentry = debugfs_create_dir("btrfs", NULL);
822	if (!btrfs_debugfs_root_dentry)
823		return -ENOMEM;
824
825	debugfs_create_u64("test", S_IRUGO | S_IWUGO, btrfs_debugfs_root_dentry,
826			&btrfs_debugfs_test);
827#endif
828	return 0;
829}
830
831int btrfs_init_sysfs(void)
832{
833	int ret;
834
835	btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
836	if (!btrfs_kset)
837		return -ENOMEM;
838
839	ret = btrfs_init_debugfs();
840	if (ret)
841		goto out1;
842
843	init_feature_attrs();
844	ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
845	if (ret)
846		goto out2;
847
848	return 0;
849out2:
850	debugfs_remove_recursive(btrfs_debugfs_root_dentry);
851out1:
852	kset_unregister(btrfs_kset);
853
854	return ret;
855}
856
857void btrfs_exit_sysfs(void)
858{
859	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
860	kset_unregister(btrfs_kset);
861	debugfs_remove_recursive(btrfs_debugfs_root_dentry);
862}
863