sysfs.c 23.3 KB
Newer Older
Chris Mason's avatar
Chris Mason committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
/*
 * Copyright (C) 2007 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

19 20 21 22 23 24
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/kobject.h>
25
#include <linux/bug.h>
26
#include <linux/genhd.h>
27
#include <linux/debugfs.h>
28

Chris Mason's avatar
Chris Mason committed
29 30 31
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
32
#include "sysfs.h"
33
#include "volumes.h"
34

35
static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
36
static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
37

38 39
static u64 get_features(struct btrfs_fs_info *fs_info,
			enum btrfs_feature_set set)
40
{
41 42 43 44 45 46 47
	struct btrfs_super_block *disk_super = fs_info->super_copy;
	if (set == FEAT_COMPAT)
		return btrfs_super_compat_flags(disk_super);
	else if (set == FEAT_COMPAT_RO)
		return btrfs_super_compat_ro_flags(disk_super);
	else
		return btrfs_super_incompat_flags(disk_super);
48 49
}

50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79
static void set_features(struct btrfs_fs_info *fs_info,
			 enum btrfs_feature_set set, u64 features)
{
	struct btrfs_super_block *disk_super = fs_info->super_copy;
	if (set == FEAT_COMPAT)
		btrfs_set_super_compat_flags(disk_super, features);
	else if (set == FEAT_COMPAT_RO)
		btrfs_set_super_compat_ro_flags(disk_super, features);
	else
		btrfs_set_super_incompat_flags(disk_super, features);
}

static int can_modify_feature(struct btrfs_feature_attr *fa)
{
	int val = 0;
	u64 set, clear;
	switch (fa->feature_set) {
	case FEAT_COMPAT:
		set = BTRFS_FEATURE_COMPAT_SAFE_SET;
		clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
		break;
	case FEAT_COMPAT_RO:
		set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
		clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
		break;
	case FEAT_INCOMPAT:
		set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
		clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
		break;
	default:
80
		pr_warn("btrfs: sysfs: unknown feature set %d\n",
81 82
				fa->feature_set);
		return 0;
83 84 85 86 87 88 89 90 91 92
	}

	if (set & fa->feature_bit)
		val |= 1;
	if (clear & fa->feature_bit)
		val |= 2;

	return val;
}

93 94
static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
				       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);
99 100 101 102
	if (fs_info) {
		u64 features = get_features(fs_info, fa->feature_set);
		if (features & fa->feature_bit)
			val = 1;
103 104
	} else
		val = can_modify_feature(fa);
105 106

	return snprintf(buf, PAGE_SIZE, "%d\n", val);
107 108
}

109 110 111 112 113 114 115 116 117 118 119 120 121 122
static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
					struct kobj_attribute *a,
					const char *buf, size_t count)
{
	struct btrfs_fs_info *fs_info;
	struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
	u64 features, set, clear;
	unsigned long val;
	int ret;

	fs_info = to_fs_info(kobj);
	if (!fs_info)
		return -EPERM;

123
	if (sb_rdonly(fs_info->sb))
124 125
		return -EROFS;

126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167
	ret = kstrtoul(skip_spaces(buf), 0, &val);
	if (ret)
		return ret;

	if (fa->feature_set == FEAT_COMPAT) {
		set = BTRFS_FEATURE_COMPAT_SAFE_SET;
		clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
	} else if (fa->feature_set == FEAT_COMPAT_RO) {
		set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
		clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
	} else {
		set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
		clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
	}

	features = get_features(fs_info, fa->feature_set);

	/* Nothing to do */
	if ((val && (features & fa->feature_bit)) ||
	    (!val && !(features & fa->feature_bit)))
		return count;

	if ((val && !(set & fa->feature_bit)) ||
	    (!val && !(clear & fa->feature_bit))) {
		btrfs_info(fs_info,
			"%sabling feature %s on mounted fs is not supported.",
			val ? "En" : "Dis", fa->kobj_attr.attr.name);
		return -EPERM;
	}

	btrfs_info(fs_info, "%s %s feature flag",
		   val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);

	spin_lock(&fs_info->super_lock);
	features = get_features(fs_info, fa->feature_set);
	if (val)
		features |= fa->feature_bit;
	else
		features &= ~fa->feature_bit;
	set_features(fs_info, fa->feature_set, features);
	spin_unlock(&fs_info->super_lock);

168 169 170 171 172
	/*
	 * We don't want to do full transaction commit from inside sysfs
	 */
	btrfs_set_pending(fs_info, COMMIT);
	wake_up_process(fs_info->transaction_kthread);
173 174 175 176

	return count;
}

177 178
static umode_t btrfs_feature_visible(struct kobject *kobj,
				     struct attribute *attr, int unused)
179
{
180 181 182 183 184 185 186 187 188 189
	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
	umode_t mode = attr->mode;

	if (fs_info) {
		struct btrfs_feature_attr *fa;
		u64 features;

		fa = attr_to_btrfs_feature_attr(attr);
		features = get_features(fs_info, fa->feature_set);

190 191 192
		if (can_modify_feature(fa))
			mode |= S_IWUSR;
		else if (!(features & fa->feature_bit))
193 194 195 196
			mode = 0;
	}

	return mode;
197 198 199 200 201 202 203 204 205 206
}

BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF);
BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA);
BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
207
BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
208
BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
209 210 211 212 213 214 215 216 217 218

static struct attribute *btrfs_supported_feature_attrs[] = {
	BTRFS_FEAT_ATTR_PTR(mixed_backref),
	BTRFS_FEAT_ATTR_PTR(default_subvol),
	BTRFS_FEAT_ATTR_PTR(mixed_groups),
	BTRFS_FEAT_ATTR_PTR(compress_lzo),
	BTRFS_FEAT_ATTR_PTR(big_metadata),
	BTRFS_FEAT_ATTR_PTR(extended_iref),
	BTRFS_FEAT_ATTR_PTR(raid56),
	BTRFS_FEAT_ATTR_PTR(skinny_metadata),
219
	BTRFS_FEAT_ATTR_PTR(no_holes),
220
	BTRFS_FEAT_ATTR_PTR(free_space_tree),
221 222 223 224 225
	NULL
};

static const struct attribute_group btrfs_feature_attr_group = {
	.name = "features",
226
	.is_visible = btrfs_feature_visible,
227 228
	.attrs = btrfs_supported_feature_attrs,
};
229

230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247
static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
{
	u64 val;
	if (lock)
		spin_lock(lock);
	val = *value_ptr;
	if (lock)
		spin_unlock(lock);
	return snprintf(buf, PAGE_SIZE, "%llu\n", val);
}

static ssize_t global_rsv_size_show(struct kobject *kobj,
				    struct kobj_attribute *ka, char *buf)
{
	struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
	return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
}
248
BTRFS_ATTR(global_rsv_size, global_rsv_size_show);
249 250 251 252 253 254 255 256

static ssize_t global_rsv_reserved_show(struct kobject *kobj,
					struct kobj_attribute *a, char *buf)
{
	struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
	return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
}
257
BTRFS_ATTR(global_rsv_reserved, global_rsv_reserved_show);
258 259

#define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
260
#define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
261 262 263 264 265 266 267 268 269 270 271 272

static ssize_t raid_bytes_show(struct kobject *kobj,
			       struct kobj_attribute *attr, char *buf);
BTRFS_RAID_ATTR(total_bytes, raid_bytes_show);
BTRFS_RAID_ATTR(used_bytes, raid_bytes_show);

static ssize_t raid_bytes_show(struct kobject *kobj,
			       struct kobj_attribute *attr, char *buf)

{
	struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
	struct btrfs_block_group_cache *block_group;
273
	int index = to_raid_kobj(kobj)->raid_type;
274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294
	u64 val = 0;

	down_read(&sinfo->groups_sem);
	list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
		if (&attr->attr == BTRFS_RAID_ATTR_PTR(total_bytes))
			val += block_group->key.offset;
		else
			val += btrfs_block_group_used(&block_group->item);
	}
	up_read(&sinfo->groups_sem);
	return snprintf(buf, PAGE_SIZE, "%llu\n", val);
}

static struct attribute *raid_attributes[] = {
	BTRFS_RAID_ATTR_PTR(total_bytes),
	BTRFS_RAID_ATTR_PTR(used_bytes),
	NULL
};

static void release_raid_kobj(struct kobject *kobj)
{
295
	kfree(to_raid_kobj(kobj));
296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311
}

struct kobj_type btrfs_raid_ktype = {
	.sysfs_ops = &kobj_sysfs_ops,
	.release = release_raid_kobj,
	.default_attrs = raid_attributes,
};

#define SPACE_INFO_ATTR(field)						\
static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,	\
					     struct kobj_attribute *a,	\
					     char *buf)			\
{									\
	struct btrfs_space_info *sinfo = to_space_info(kobj);		\
	return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);	\
}									\
312
BTRFS_ATTR(field, btrfs_space_info_show_##field)
313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328

static ssize_t btrfs_space_info_show_total_bytes_pinned(struct kobject *kobj,
						       struct kobj_attribute *a,
						       char *buf)
{
	struct btrfs_space_info *sinfo = to_space_info(kobj);
	s64 val = percpu_counter_sum(&sinfo->total_bytes_pinned);
	return snprintf(buf, PAGE_SIZE, "%lld\n", val);
}

SPACE_INFO_ATTR(flags);
SPACE_INFO_ATTR(total_bytes);
SPACE_INFO_ATTR(bytes_used);
SPACE_INFO_ATTR(bytes_pinned);
SPACE_INFO_ATTR(bytes_reserved);
SPACE_INFO_ATTR(bytes_may_use);
329
SPACE_INFO_ATTR(bytes_readonly);
330 331
SPACE_INFO_ATTR(disk_used);
SPACE_INFO_ATTR(disk_total);
332
BTRFS_ATTR(total_bytes_pinned, btrfs_space_info_show_total_bytes_pinned);
333 334 335 336 337 338 339 340

static struct attribute *space_info_attrs[] = {
	BTRFS_ATTR_PTR(flags),
	BTRFS_ATTR_PTR(total_bytes),
	BTRFS_ATTR_PTR(bytes_used),
	BTRFS_ATTR_PTR(bytes_pinned),
	BTRFS_ATTR_PTR(bytes_reserved),
	BTRFS_ATTR_PTR(bytes_may_use),
341
	BTRFS_ATTR_PTR(bytes_readonly),
342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366
	BTRFS_ATTR_PTR(disk_used),
	BTRFS_ATTR_PTR(disk_total),
	BTRFS_ATTR_PTR(total_bytes_pinned),
	NULL,
};

static void space_info_release(struct kobject *kobj)
{
	struct btrfs_space_info *sinfo = to_space_info(kobj);
	percpu_counter_destroy(&sinfo->total_bytes_pinned);
	kfree(sinfo);
}

struct kobj_type space_info_ktype = {
	.sysfs_ops = &kobj_sysfs_ops,
	.release = space_info_release,
	.default_attrs = space_info_attrs,
};

static const struct attribute *allocation_attrs[] = {
	BTRFS_ATTR_PTR(global_rsv_reserved),
	BTRFS_ATTR_PTR(global_rsv_size),
	NULL,
};

367 368 369 370
static ssize_t btrfs_label_show(struct kobject *kobj,
				struct kobj_attribute *a, char *buf)
{
	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
371
	char *label = fs_info->super_copy->label;
372 373 374 375 376 377 378
	ssize_t ret;

	spin_lock(&fs_info->super_lock);
	ret = snprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label);
	spin_unlock(&fs_info->super_lock);

	return ret;
379 380 381 382 383 384 385
}

static ssize_t btrfs_label_store(struct kobject *kobj,
				 struct kobj_attribute *a,
				 const char *buf, size_t len)
{
	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
386
	size_t p_len;
387

388 389 390
	if (!fs_info)
		return -EPERM;

391
	if (sb_rdonly(fs_info->sb))
392 393
		return -EROFS;

394 395 396 397 398 399 400
	/*
	 * p_len is the len until the first occurrence of either
	 * '\n' or '\0'
	 */
	p_len = strcspn(buf, "\n");

	if (p_len >= BTRFS_LABEL_SIZE)
401 402
		return -EINVAL;

403
	spin_lock(&fs_info->super_lock);
404 405
	memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
	memcpy(fs_info->super_copy->label, buf, p_len);
406
	spin_unlock(&fs_info->super_lock);
407

408 409 410 411 412
	/*
	 * We don't want to do full transaction commit from inside sysfs
	 */
	btrfs_set_pending(fs_info, COMMIT);
	wake_up_process(fs_info->transaction_kthread);
413

414
	return len;
415
}
416
BTRFS_ATTR_RW(label, btrfs_label_show, btrfs_label_store);
417

418 419 420 421 422 423 424 425
static ssize_t btrfs_nodesize_show(struct kobject *kobj,
				struct kobj_attribute *a, char *buf)
{
	struct btrfs_fs_info *fs_info = to_fs_info(kobj);

	return snprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize);
}

426
BTRFS_ATTR(nodesize, btrfs_nodesize_show);
427 428 429 430 431 432

static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
				struct kobj_attribute *a, char *buf)
{
	struct btrfs_fs_info *fs_info = to_fs_info(kobj);

433 434
	return snprintf(buf, PAGE_SIZE, "%u\n",
			fs_info->super_copy->sectorsize);
435 436
}

437
BTRFS_ATTR(sectorsize, btrfs_sectorsize_show);
438 439 440 441 442 443

static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
				struct kobj_attribute *a, char *buf)
{
	struct btrfs_fs_info *fs_info = to_fs_info(kobj);

444 445
	return snprintf(buf, PAGE_SIZE, "%u\n",
			fs_info->super_copy->sectorsize);
446 447
}

448
BTRFS_ATTR(clone_alignment, btrfs_clone_alignment_show);
449

450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489
static ssize_t quota_override_show(struct kobject *kobj,
				   struct kobj_attribute *a, char *buf)
{
	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
	int quota_override;

	quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
	return snprintf(buf, PAGE_SIZE, "%d\n", quota_override);
}

static ssize_t quota_override_store(struct kobject *kobj,
				    struct kobj_attribute *a,
				    const char *buf, size_t len)
{
	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
	unsigned long knob;
	int err;

	if (!fs_info)
		return -EPERM;

	if (!capable(CAP_SYS_RESOURCE))
		return -EPERM;

	err = kstrtoul(buf, 10, &knob);
	if (err)
		return err;
	if (knob > 1)
		return -EINVAL;

	if (knob)
		set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
	else
		clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);

	return len;
}

BTRFS_ATTR_RW(quota_override, quota_override_show, quota_override_store);

490
static const struct attribute *btrfs_attrs[] = {
491
	BTRFS_ATTR_PTR(label),
492 493 494
	BTRFS_ATTR_PTR(nodesize),
	BTRFS_ATTR_PTR(sectorsize),
	BTRFS_ATTR_PTR(clone_alignment),
495
	BTRFS_ATTR_PTR(quota_override),
496 497 498
	NULL,
};

499
static void btrfs_release_fsid_kobj(struct kobject *kobj)
500
{
501
	struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
502

503
	memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
504
	complete(&fs_devs->kobj_unregister);
505 506 507 508
}

static struct kobj_type btrfs_ktype = {
	.sysfs_ops	= &kobj_sysfs_ops,
509
	.release	= btrfs_release_fsid_kobj,
510 511
};

512 513 514 515
static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
{
	if (kobj->ktype != &btrfs_ktype)
		return NULL;
516
	return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
517 518
}

519 520 521 522
static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
{
	if (kobj->ktype != &btrfs_ktype)
		return NULL;
523
	return to_fs_devs(kobj)->fs_info;
524
}
525

526 527 528 529
#define NUM_FEATURE_BITS 64
static char btrfs_unknown_feature_names[3][NUM_FEATURE_BITS][13];
static struct btrfs_feature_attr btrfs_feature_attrs[3][NUM_FEATURE_BITS];

530
static const u64 supported_feature_masks[3] = {
531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563
	[FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
	[FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
	[FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
};

static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
{
	int set;

	for (set = 0; set < FEAT_MAX; set++) {
		int i;
		struct attribute *attrs[2];
		struct attribute_group agroup = {
			.name = "features",
			.attrs = attrs,
		};
		u64 features = get_features(fs_info, set);
		features &= ~supported_feature_masks[set];

		if (!features)
			continue;

		attrs[1] = NULL;
		for (i = 0; i < NUM_FEATURE_BITS; i++) {
			struct btrfs_feature_attr *fa;

			if (!(features & (1ULL << i)))
				continue;

			fa = &btrfs_feature_attrs[set][i];
			attrs[0] = &fa->kobj_attr.attr;
			if (add) {
				int ret;
564
				ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
565 566 567 568
							&agroup);
				if (ret)
					return ret;
			} else
569
				sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
570 571 572 573 574 575 576
						    &agroup);
		}

	}
	return 0;
}

577
static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
578
{
579 580 581 582
	if (fs_devs->device_dir_kobj) {
		kobject_del(fs_devs->device_dir_kobj);
		kobject_put(fs_devs->device_dir_kobj);
		fs_devs->device_dir_kobj = NULL;
583 584
	}

585 586 587
	if (fs_devs->fsid_kobj.state_initialized) {
		kobject_del(&fs_devs->fsid_kobj);
		kobject_put(&fs_devs->fsid_kobj);
588 589
		wait_for_completion(&fs_devs->kobj_unregister);
	}
590 591
}

592
/* when fs_devs is NULL it will remove all fsid kobject */
593
void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
594 595 596 597 598 599 600 601 602 603 604 605 606
{
	struct list_head *fs_uuids = btrfs_get_fs_uuids();

	if (fs_devs) {
		__btrfs_sysfs_remove_fsid(fs_devs);
		return;
	}

	list_for_each_entry(fs_devs, fs_uuids, list) {
		__btrfs_sysfs_remove_fsid(fs_devs);
	}
}

607
void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
608
{
609 610
	btrfs_reset_fs_info_ptr(fs_info);

611 612 613 614 615 616
	if (fs_info->space_info_kobj) {
		sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
		kobject_del(fs_info->space_info_kobj);
		kobject_put(fs_info->space_info_kobj);
	}
	addrm_unknown_feature_attrs(fs_info, false);
617 618
	sysfs_remove_group(&fs_info->fs_devices->fsid_kobj, &btrfs_feature_attr_group);
	sysfs_remove_files(&fs_info->fs_devices->fsid_kobj, btrfs_attrs);
619
	btrfs_sysfs_rm_device_link(fs_info->fs_devices, NULL);
620 621
}

622 623 624 625 626 627
const char * const btrfs_feature_set_names[3] = {
	[FEAT_COMPAT]	 = "compat",
	[FEAT_COMPAT_RO] = "compat_ro",
	[FEAT_INCOMPAT]	 = "incompat",
};

628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652
char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
{
	size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
	int len = 0;
	int i;
	char *str;

	str = kmalloc(bufsize, GFP_KERNEL);
	if (!str)
		return str;

	for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
		const char *name;

		if (!(flags & (1ULL << i)))
			continue;

		name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
		len += snprintf(str + len, bufsize - len, "%s%s",
				len ? "," : "", name);
	}

	return str;
}

653 654 655 656 657 658 659 660 661 662
static void init_feature_attrs(void)
{
	struct btrfs_feature_attr *fa;
	int set, i;

	BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) !=
		     ARRAY_SIZE(btrfs_feature_attrs));
	BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) !=
		     ARRAY_SIZE(btrfs_feature_attrs[0]));

663 664 665 666
	memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
	memset(btrfs_unknown_feature_names, 0,
	       sizeof(btrfs_unknown_feature_names));

667 668 669
	for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
		struct btrfs_feature_attr *sfa;
		struct attribute *a = btrfs_supported_feature_attrs[i];
670
		int bit;
671
		sfa = attr_to_btrfs_feature_attr(a);
672 673
		bit = ilog2(sfa->feature_bit);
		fa = &btrfs_feature_attrs[sfa->feature_set][bit];
674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696

		fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
	}

	for (set = 0; set < FEAT_MAX; set++) {
		for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
			char *name = btrfs_unknown_feature_names[set][i];
			fa = &btrfs_feature_attrs[set][i];

			if (fa->kobj_attr.attr.name)
				continue;

			snprintf(name, 13, "%s:%u",
				 btrfs_feature_set_names[set], i);

			fa->kobj_attr.attr.name = name;
			fa->kobj_attr.attr.mode = S_IRUGO;
			fa->feature_set = set;
			fa->feature_bit = 1ULL << i;
		}
	}
}

697 698
/* when one_device is NULL, it removes all device links */

699
int btrfs_sysfs_rm_device_link(struct btrfs_fs_devices *fs_devices,
700 701 702 703 704
		struct btrfs_device *one_device)
{
	struct hd_struct *disk;
	struct kobject *disk_kobj;

705
	if (!fs_devices->device_dir_kobj)
706 707
		return -EINVAL;

708
	if (one_device && one_device->bdev) {
709 710 711
		disk = one_device->bdev->bd_part;
		disk_kobj = &part_to_dev(disk)->kobj;

712
		sysfs_remove_link(fs_devices->device_dir_kobj,
713 714 715
						disk_kobj->name);
	}

716 717 718 719
	if (one_device)
		return 0;

	list_for_each_entry(one_device,
720
			&fs_devices->devices, dev_list) {
721 722 723 724 725
		if (!one_device->bdev)
			continue;
		disk = one_device->bdev->bd_part;
		disk_kobj = &part_to_dev(disk)->kobj;

726
		sysfs_remove_link(fs_devices->device_dir_kobj,
727 728 729
						disk_kobj->name);
	}

730 731 732
	return 0;
}

733
int btrfs_sysfs_add_device(struct btrfs_fs_devices *fs_devs)
734
{
735 736
	if (!fs_devs->device_dir_kobj)
		fs_devs->device_dir_kobj = kobject_create_and_add("devices",
737
						&fs_devs->fsid_kobj);
738

739
	if (!fs_devs->device_dir_kobj)
740 741
		return -ENOMEM;

742 743 744
	return 0;
}

745
int btrfs_sysfs_add_device_link(struct btrfs_fs_devices *fs_devices,
746
				struct btrfs_device *one_device)
747 748 749 750
{
	int error = 0;
	struct btrfs_device *dev;

751
	list_for_each_entry(dev, &fs_devices->devices, dev_list) {
752 753 754 755 756 757
		struct hd_struct *disk;
		struct kobject *disk_kobj;

		if (!dev->bdev)
			continue;

758 759 760
		if (one_device && one_device != dev)
			continue;

761 762
		disk = dev->bdev->bd_part;
		disk_kobj = &part_to_dev(disk)->kobj;
763

764
		error = sysfs_create_link(fs_devices->device_dir_kobj,
765 766 767 768 769 770 771 772
					  disk_kobj, disk_kobj->name);
		if (error)
			break;
	}

	return error;
}

773 774 775
/* /sys/fs/btrfs/ entry */
static struct kset *btrfs_kset;

776 777 778 779 780 781
/* /sys/kernel/debug/btrfs */
static struct dentry *btrfs_debugfs_root_dentry;

/* Debugging tunables and exported data */
u64 btrfs_debugfs_test;

782 783 784 785
/*
 * Can be called by the device discovery thread.
 * And parent can be specified for seed device
 */
786
int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs,
787
				struct kobject *parent)
788 789 790
{
	int error;

791
	init_completion(&fs_devs->kobj_unregister);
792 793
	fs_devs->fsid_kobj.kset = btrfs_kset;
	error = kobject_init_and_add(&fs_devs->fsid_kobj,
794
				&btrfs_ktype, parent, "%pU", fs_devs->fsid);
795 796 797
	return error;
}

798
int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
799 800
{
	int error;
801
	struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
802
	struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
803

804 805
	btrfs_set_fs_info_ptr(fs_info);

806
	error = btrfs_sysfs_add_device_link(fs_devs, NULL);
807
	if (error)
808 809
		return error;

810
	error = sysfs_create_files(fsid_kobj, btrfs_attrs);
811
	if (error) {
812
		btrfs_sysfs_rm_device_link(fs_devs, NULL);
813 814
		return error;
	}
815

816
	error = sysfs_create_group(fsid_kobj,
817 818 819 820
				   &btrfs_feature_attr_group);
	if (error)
		goto failure;

821
	error = addrm_unknown_feature_attrs(fs_info, true);
822 823 824
	if (error)
		goto failure;

825
	fs_info->space_info_kobj = kobject_create_and_add("allocation",
826
						  fsid_kobj);
827 828 829 830 831 832 833 834 835
	if (!fs_info->space_info_kobj) {
		error = -ENOMEM;
		goto failure;
	}

	error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
	if (error)
		goto failure;

836 837
	return 0;
failure:
838
	btrfs_sysfs_remove_mounted(fs_info);
839 840 841
	return error;
}

842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863

/*
 * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
 * values in superblock. Call after any changes to incompat/compat_ro flags
 */
void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
		u64 bit, enum btrfs_feature_set set)
{
	struct btrfs_fs_devices *fs_devs;
	struct kobject *fsid_kobj;
	u64 features;
	int ret;

	if (!fs_info)
		return;

	features = get_features(fs_info, set);
	ASSERT(bit & supported_feature_masks[set]);

	fs_devs = fs_info->fs_devices;
	fsid_kobj = &fs_devs->fsid_kobj;

864 865 866
	if (!fsid_kobj->state_initialized)
		return;

867 868 869 870 871 872 873 874
	/*
	 * FIXME: this is too heavy to update just one value, ideally we'd like
	 * to use sysfs_update_group but some refactoring is needed first.
	 */
	sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
	ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
}

875 876 877 878 879 880 881
static int btrfs_init_debugfs(void)
{
#ifdef CONFIG_DEBUG_FS
	btrfs_debugfs_root_dentry = debugfs_create_dir("btrfs", NULL);
	if (!btrfs_debugfs_root_dentry)
		return -ENOMEM;

882 883 884 885 886 887 888
	/*
	 * Example code, how to export data through debugfs.
	 *
	 * file:        /sys/kernel/debug/btrfs/test
	 * contents of: btrfs_debugfs_test
	 */
#ifdef CONFIG_BTRFS_DEBUG
889
	debugfs_create_u64("test", S_IRUGO | S_IWUSR, btrfs_debugfs_root_dentry,
890
			&btrfs_debugfs_test);
891 892
#endif

893 894 895 896
#endif
	return 0;
}

897
int btrfs_init_sysfs(void)
898
{
899
	int ret;
900

901 902 903
	btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
	if (!btrfs_kset)
		return -ENOMEM;
904

905 906
	ret = btrfs_init_debugfs();
	if (ret)
907
		goto out1;
908

909
	init_feature_attrs();
910
	ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
911 912 913 914 915 916 917 918
	if (ret)
		goto out2;

	return 0;
out2:
	debugfs_remove_recursive(btrfs_debugfs_root_dentry);
out1:
	kset_unregister(btrfs_kset);
919

920
	return ret;
921 922
}

923
void btrfs_exit_sysfs(void)
924
{
925
	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
926
	kset_unregister(btrfs_kset);
927
	debugfs_remove_recursive(btrfs_debugfs_root_dentry);
928
}
929