1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2007 Oracle.  All rights reserved.
4  */
5 
6 #include <linux/sched.h>
7 #include <linux/sched/mm.h>
8 #include <linux/slab.h>
9 #include <linux/spinlock.h>
10 #include <linux/completion.h>
11 #include <linux/bug.h>
12 #include <crypto/hash.h>
13 
14 #include "ctree.h"
15 #include "discard.h"
16 #include "disk-io.h"
17 #include "send.h"
18 #include "transaction.h"
19 #include "sysfs.h"
20 #include "volumes.h"
21 #include "space-info.h"
22 #include "block-group.h"
23 #include "qgroup.h"
24 #include "misc.h"
25 
26 /*
27  * Structure name                       Path
28  * --------------------------------------------------------------------------
29  * btrfs_supported_static_feature_attrs /sys/fs/btrfs/features
30  * btrfs_supported_feature_attrs	/sys/fs/btrfs/features and
31  *					/sys/fs/btrfs/<uuid>/features
32  * btrfs_attrs				/sys/fs/btrfs/<uuid>
33  * devid_attrs				/sys/fs/btrfs/<uuid>/devinfo/<devid>
34  * allocation_attrs			/sys/fs/btrfs/<uuid>/allocation
35  * qgroup_attrs				/sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>
36  * space_info_attrs			/sys/fs/btrfs/<uuid>/allocation/<bg-type>
37  * raid_attrs				/sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>
38  * discard_attrs			/sys/fs/btrfs/<uuid>/discard
39  *
40  * When built with BTRFS_CONFIG_DEBUG:
41  *
42  * btrfs_debug_feature_attrs		/sys/fs/btrfs/debug
43  * btrfs_debug_mount_attrs		/sys/fs/btrfs/<uuid>/debug
44  */
45 
46 struct btrfs_feature_attr {
47 	struct kobj_attribute kobj_attr;
48 	enum btrfs_feature_set feature_set;
49 	u64 feature_bit;
50 };
51 
52 /* For raid type sysfs entries */
53 struct raid_kobject {
54 	u64 flags;
55 	struct kobject kobj;
56 };
57 
58 #define __INIT_KOBJ_ATTR(_name, _mode, _show, _store)			\
59 {									\
60 	.attr	= { .name = __stringify(_name), .mode = _mode },	\
61 	.show	= _show,						\
62 	.store	= _store,						\
63 }
64 
65 #define BTRFS_ATTR_W(_prefix, _name, _store)			        \
66 	static struct kobj_attribute btrfs_attr_##_prefix##_##_name =	\
67 			__INIT_KOBJ_ATTR(_name, 0200, NULL, _store)
68 
69 #define BTRFS_ATTR_RW(_prefix, _name, _show, _store)			\
70 	static struct kobj_attribute btrfs_attr_##_prefix##_##_name =	\
71 			__INIT_KOBJ_ATTR(_name, 0644, _show, _store)
72 
73 #define BTRFS_ATTR(_prefix, _name, _show)				\
74 	static struct kobj_attribute btrfs_attr_##_prefix##_##_name =	\
75 			__INIT_KOBJ_ATTR(_name, 0444, _show, NULL)
76 
77 #define BTRFS_ATTR_PTR(_prefix, _name)					\
78 	(&btrfs_attr_##_prefix##_##_name.attr)
79 
80 #define BTRFS_FEAT_ATTR(_name, _feature_set, _feature_prefix, _feature_bit)  \
81 static struct btrfs_feature_attr btrfs_attr_features_##_name = {	     \
82 	.kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO,			     \
83 				      btrfs_feature_attr_show,		     \
84 				      btrfs_feature_attr_store),	     \
85 	.feature_set	= _feature_set,					     \
86 	.feature_bit	= _feature_prefix ##_## _feature_bit,		     \
87 }
88 #define BTRFS_FEAT_ATTR_PTR(_name)					     \
89 	(&btrfs_attr_features_##_name.kobj_attr.attr)
90 
91 #define BTRFS_FEAT_ATTR_COMPAT(name, feature) \
92 	BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature)
93 #define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \
94 	BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
95 #define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
96 	BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
97 
98 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
99 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
100 static struct kobject *get_btrfs_kobj(struct kobject *kobj);
101 
to_btrfs_feature_attr(struct kobj_attribute * a)102 static struct btrfs_feature_attr *to_btrfs_feature_attr(struct kobj_attribute *a)
103 {
104 	return container_of(a, struct btrfs_feature_attr, kobj_attr);
105 }
106 
attr_to_btrfs_attr(struct attribute * attr)107 static struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr)
108 {
109 	return container_of(attr, struct kobj_attribute, attr);
110 }
111 
attr_to_btrfs_feature_attr(struct attribute * attr)112 static struct btrfs_feature_attr *attr_to_btrfs_feature_attr(
113 		struct attribute *attr)
114 {
115 	return to_btrfs_feature_attr(attr_to_btrfs_attr(attr));
116 }
117 
get_features(struct btrfs_fs_info * fs_info,enum btrfs_feature_set set)118 static u64 get_features(struct btrfs_fs_info *fs_info,
119 			enum btrfs_feature_set set)
120 {
121 	struct btrfs_super_block *disk_super = fs_info->super_copy;
122 	if (set == FEAT_COMPAT)
123 		return btrfs_super_compat_flags(disk_super);
124 	else if (set == FEAT_COMPAT_RO)
125 		return btrfs_super_compat_ro_flags(disk_super);
126 	else
127 		return btrfs_super_incompat_flags(disk_super);
128 }
129 
set_features(struct btrfs_fs_info * fs_info,enum btrfs_feature_set set,u64 features)130 static void set_features(struct btrfs_fs_info *fs_info,
131 			 enum btrfs_feature_set set, u64 features)
132 {
133 	struct btrfs_super_block *disk_super = fs_info->super_copy;
134 	if (set == FEAT_COMPAT)
135 		btrfs_set_super_compat_flags(disk_super, features);
136 	else if (set == FEAT_COMPAT_RO)
137 		btrfs_set_super_compat_ro_flags(disk_super, features);
138 	else
139 		btrfs_set_super_incompat_flags(disk_super, features);
140 }
141 
can_modify_feature(struct btrfs_feature_attr * fa)142 static int can_modify_feature(struct btrfs_feature_attr *fa)
143 {
144 	int val = 0;
145 	u64 set, clear;
146 	switch (fa->feature_set) {
147 	case FEAT_COMPAT:
148 		set = BTRFS_FEATURE_COMPAT_SAFE_SET;
149 		clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
150 		break;
151 	case FEAT_COMPAT_RO:
152 		set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
153 		clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
154 		break;
155 	case FEAT_INCOMPAT:
156 		set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
157 		clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
158 		break;
159 	default:
160 		pr_warn("btrfs: sysfs: unknown feature set %d\n",
161 				fa->feature_set);
162 		return 0;
163 	}
164 
165 	if (set & fa->feature_bit)
166 		val |= 1;
167 	if (clear & fa->feature_bit)
168 		val |= 2;
169 
170 	return val;
171 }
172 
btrfs_feature_attr_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)173 static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
174 				       struct kobj_attribute *a, char *buf)
175 {
176 	int val = 0;
177 	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
178 	struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
179 	if (fs_info) {
180 		u64 features = get_features(fs_info, fa->feature_set);
181 		if (features & fa->feature_bit)
182 			val = 1;
183 	} else
184 		val = can_modify_feature(fa);
185 
186 	return sysfs_emit(buf, "%d\n", val);
187 }
188 
btrfs_feature_attr_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t count)189 static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
190 					struct kobj_attribute *a,
191 					const char *buf, size_t count)
192 {
193 	struct btrfs_fs_info *fs_info;
194 	struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
195 	u64 features, set, clear;
196 	unsigned long val;
197 	int ret;
198 
199 	fs_info = to_fs_info(kobj);
200 	if (!fs_info)
201 		return -EPERM;
202 
203 	if (sb_rdonly(fs_info->sb))
204 		return -EROFS;
205 
206 	ret = kstrtoul(skip_spaces(buf), 0, &val);
207 	if (ret)
208 		return ret;
209 
210 	if (fa->feature_set == FEAT_COMPAT) {
211 		set = BTRFS_FEATURE_COMPAT_SAFE_SET;
212 		clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
213 	} else if (fa->feature_set == FEAT_COMPAT_RO) {
214 		set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
215 		clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
216 	} else {
217 		set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
218 		clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
219 	}
220 
221 	features = get_features(fs_info, fa->feature_set);
222 
223 	/* Nothing to do */
224 	if ((val && (features & fa->feature_bit)) ||
225 	    (!val && !(features & fa->feature_bit)))
226 		return count;
227 
228 	if ((val && !(set & fa->feature_bit)) ||
229 	    (!val && !(clear & fa->feature_bit))) {
230 		btrfs_info(fs_info,
231 			"%sabling feature %s on mounted fs is not supported.",
232 			val ? "En" : "Dis", fa->kobj_attr.attr.name);
233 		return -EPERM;
234 	}
235 
236 	btrfs_info(fs_info, "%s %s feature flag",
237 		   val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
238 
239 	spin_lock(&fs_info->super_lock);
240 	features = get_features(fs_info, fa->feature_set);
241 	if (val)
242 		features |= fa->feature_bit;
243 	else
244 		features &= ~fa->feature_bit;
245 	set_features(fs_info, fa->feature_set, features);
246 	spin_unlock(&fs_info->super_lock);
247 
248 	/*
249 	 * We don't want to do full transaction commit from inside sysfs
250 	 */
251 	btrfs_set_pending(fs_info, COMMIT);
252 	wake_up_process(fs_info->transaction_kthread);
253 
254 	return count;
255 }
256 
btrfs_feature_visible(struct kobject * kobj,struct attribute * attr,int unused)257 static umode_t btrfs_feature_visible(struct kobject *kobj,
258 				     struct attribute *attr, int unused)
259 {
260 	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
261 	umode_t mode = attr->mode;
262 
263 	if (fs_info) {
264 		struct btrfs_feature_attr *fa;
265 		u64 features;
266 
267 		fa = attr_to_btrfs_feature_attr(attr);
268 		features = get_features(fs_info, fa->feature_set);
269 
270 		if (can_modify_feature(fa))
271 			mode |= S_IWUSR;
272 		else if (!(features & fa->feature_bit))
273 			mode = 0;
274 	}
275 
276 	return mode;
277 }
278 
279 BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
280 BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
281 BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
282 BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD);
283 BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
284 BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
285 BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
286 BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
287 BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
288 BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
289 BTRFS_FEAT_ATTR_COMPAT_RO(block_group_tree, BLOCK_GROUP_TREE);
290 BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
291 #ifdef CONFIG_BLK_DEV_ZONED
292 BTRFS_FEAT_ATTR_INCOMPAT(zoned, ZONED);
293 #endif
294 #ifdef CONFIG_BTRFS_DEBUG
295 /* Remove once support for extent tree v2 is feature complete */
296 BTRFS_FEAT_ATTR_INCOMPAT(extent_tree_v2, EXTENT_TREE_V2);
297 #endif
298 #ifdef CONFIG_FS_VERITY
299 BTRFS_FEAT_ATTR_COMPAT_RO(verity, VERITY);
300 #endif
301 
302 /*
303  * Features which depend on feature bits and may differ between each fs.
304  *
305  * /sys/fs/btrfs/features      - all available features implemented by this version
306  * /sys/fs/btrfs/UUID/features - features of the fs which are enabled or
307  *                               can be changed on a mounted filesystem.
308  */
309 static struct attribute *btrfs_supported_feature_attrs[] = {
310 	BTRFS_FEAT_ATTR_PTR(default_subvol),
311 	BTRFS_FEAT_ATTR_PTR(mixed_groups),
312 	BTRFS_FEAT_ATTR_PTR(compress_lzo),
313 	BTRFS_FEAT_ATTR_PTR(compress_zstd),
314 	BTRFS_FEAT_ATTR_PTR(extended_iref),
315 	BTRFS_FEAT_ATTR_PTR(raid56),
316 	BTRFS_FEAT_ATTR_PTR(skinny_metadata),
317 	BTRFS_FEAT_ATTR_PTR(no_holes),
318 	BTRFS_FEAT_ATTR_PTR(metadata_uuid),
319 	BTRFS_FEAT_ATTR_PTR(free_space_tree),
320 	BTRFS_FEAT_ATTR_PTR(raid1c34),
321 	BTRFS_FEAT_ATTR_PTR(block_group_tree),
322 #ifdef CONFIG_BLK_DEV_ZONED
323 	BTRFS_FEAT_ATTR_PTR(zoned),
324 #endif
325 #ifdef CONFIG_BTRFS_DEBUG
326 	BTRFS_FEAT_ATTR_PTR(extent_tree_v2),
327 #endif
328 #ifdef CONFIG_FS_VERITY
329 	BTRFS_FEAT_ATTR_PTR(verity),
330 #endif
331 	NULL
332 };
333 
334 static const struct attribute_group btrfs_feature_attr_group = {
335 	.name = "features",
336 	.is_visible = btrfs_feature_visible,
337 	.attrs = btrfs_supported_feature_attrs,
338 };
339 
rmdir_subvol_show(struct kobject * kobj,struct kobj_attribute * ka,char * buf)340 static ssize_t rmdir_subvol_show(struct kobject *kobj,
341 				 struct kobj_attribute *ka, char *buf)
342 {
343 	return sysfs_emit(buf, "0\n");
344 }
345 BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
346 
supported_checksums_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)347 static ssize_t supported_checksums_show(struct kobject *kobj,
348 					struct kobj_attribute *a, char *buf)
349 {
350 	ssize_t ret = 0;
351 	int i;
352 
353 	for (i = 0; i < btrfs_get_num_csums(); i++) {
354 		/*
355 		 * This "trick" only works as long as 'enum btrfs_csum_type' has
356 		 * no holes in it
357 		 */
358 		ret += sysfs_emit_at(buf, ret, "%s%s", (i == 0 ? "" : " "),
359 				     btrfs_super_csum_name(i));
360 
361 	}
362 
363 	ret += sysfs_emit_at(buf, ret, "\n");
364 	return ret;
365 }
366 BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
367 
send_stream_version_show(struct kobject * kobj,struct kobj_attribute * ka,char * buf)368 static ssize_t send_stream_version_show(struct kobject *kobj,
369 					struct kobj_attribute *ka, char *buf)
370 {
371 	return sysfs_emit(buf, "%d\n", BTRFS_SEND_STREAM_VERSION);
372 }
373 BTRFS_ATTR(static_feature, send_stream_version, send_stream_version_show);
374 
375 static const char *rescue_opts[] = {
376 	"usebackuproot",
377 	"nologreplay",
378 	"ignorebadroots",
379 	"ignoredatacsums",
380 	"all",
381 };
382 
supported_rescue_options_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)383 static ssize_t supported_rescue_options_show(struct kobject *kobj,
384 					     struct kobj_attribute *a,
385 					     char *buf)
386 {
387 	ssize_t ret = 0;
388 	int i;
389 
390 	for (i = 0; i < ARRAY_SIZE(rescue_opts); i++)
391 		ret += sysfs_emit_at(buf, ret, "%s%s", (i ? " " : ""), rescue_opts[i]);
392 	ret += sysfs_emit_at(buf, ret, "\n");
393 	return ret;
394 }
395 BTRFS_ATTR(static_feature, supported_rescue_options,
396 	   supported_rescue_options_show);
397 
supported_sectorsizes_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)398 static ssize_t supported_sectorsizes_show(struct kobject *kobj,
399 					  struct kobj_attribute *a,
400 					  char *buf)
401 {
402 	ssize_t ret = 0;
403 
404 	/* An artificial limit to only support 4K and PAGE_SIZE */
405 	if (PAGE_SIZE > SZ_4K)
406 		ret += sysfs_emit_at(buf, ret, "%u ", SZ_4K);
407 	ret += sysfs_emit_at(buf, ret, "%lu\n", PAGE_SIZE);
408 
409 	return ret;
410 }
411 BTRFS_ATTR(static_feature, supported_sectorsizes,
412 	   supported_sectorsizes_show);
413 
414 /*
415  * Features which only depend on kernel version.
416  *
417  * These are listed in /sys/fs/btrfs/features along with
418  * btrfs_supported_feature_attrs.
419  */
420 static struct attribute *btrfs_supported_static_feature_attrs[] = {
421 	BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
422 	BTRFS_ATTR_PTR(static_feature, supported_checksums),
423 	BTRFS_ATTR_PTR(static_feature, send_stream_version),
424 	BTRFS_ATTR_PTR(static_feature, supported_rescue_options),
425 	BTRFS_ATTR_PTR(static_feature, supported_sectorsizes),
426 	NULL
427 };
428 
429 static const struct attribute_group btrfs_static_feature_attr_group = {
430 	.name = "features",
431 	.attrs = btrfs_supported_static_feature_attrs,
432 };
433 
434 /*
435  * Discard statistics and tunables
436  */
437 #define discard_to_fs_info(_kobj)	to_fs_info(get_btrfs_kobj(_kobj))
438 
btrfs_discardable_bytes_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)439 static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
440 					    struct kobj_attribute *a,
441 					    char *buf)
442 {
443 	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
444 
445 	return sysfs_emit(buf, "%lld\n",
446 			atomic64_read(&fs_info->discard_ctl.discardable_bytes));
447 }
448 BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
449 
btrfs_discardable_extents_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)450 static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
451 					      struct kobj_attribute *a,
452 					      char *buf)
453 {
454 	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
455 
456 	return sysfs_emit(buf, "%d\n",
457 			atomic_read(&fs_info->discard_ctl.discardable_extents));
458 }
459 BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
460 
btrfs_discard_bitmap_bytes_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)461 static ssize_t btrfs_discard_bitmap_bytes_show(struct kobject *kobj,
462 					       struct kobj_attribute *a,
463 					       char *buf)
464 {
465 	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
466 
467 	return sysfs_emit(buf, "%llu\n",
468 			  fs_info->discard_ctl.discard_bitmap_bytes);
469 }
470 BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
471 
btrfs_discard_bytes_saved_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)472 static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj,
473 					      struct kobj_attribute *a,
474 					      char *buf)
475 {
476 	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
477 
478 	return sysfs_emit(buf, "%lld\n",
479 		atomic64_read(&fs_info->discard_ctl.discard_bytes_saved));
480 }
481 BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
482 
btrfs_discard_extent_bytes_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)483 static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj,
484 					       struct kobj_attribute *a,
485 					       char *buf)
486 {
487 	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
488 
489 	return sysfs_emit(buf, "%llu\n",
490 			  fs_info->discard_ctl.discard_extent_bytes);
491 }
492 BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
493 
btrfs_discard_iops_limit_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)494 static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
495 					     struct kobj_attribute *a,
496 					     char *buf)
497 {
498 	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
499 
500 	return sysfs_emit(buf, "%u\n",
501 			  READ_ONCE(fs_info->discard_ctl.iops_limit));
502 }
503 
btrfs_discard_iops_limit_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)504 static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
505 					      struct kobj_attribute *a,
506 					      const char *buf, size_t len)
507 {
508 	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
509 	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
510 	u32 iops_limit;
511 	int ret;
512 
513 	ret = kstrtou32(buf, 10, &iops_limit);
514 	if (ret)
515 		return -EINVAL;
516 
517 	WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
518 	btrfs_discard_calc_delay(discard_ctl);
519 	btrfs_discard_schedule_work(discard_ctl, true);
520 	return len;
521 }
522 BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
523 	      btrfs_discard_iops_limit_store);
524 
btrfs_discard_kbps_limit_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)525 static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
526 					     struct kobj_attribute *a,
527 					     char *buf)
528 {
529 	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
530 
531 	return sysfs_emit(buf, "%u\n",
532 			  READ_ONCE(fs_info->discard_ctl.kbps_limit));
533 }
534 
btrfs_discard_kbps_limit_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)535 static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
536 					      struct kobj_attribute *a,
537 					      const char *buf, size_t len)
538 {
539 	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
540 	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
541 	u32 kbps_limit;
542 	int ret;
543 
544 	ret = kstrtou32(buf, 10, &kbps_limit);
545 	if (ret)
546 		return -EINVAL;
547 
548 	WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
549 	btrfs_discard_schedule_work(discard_ctl, true);
550 	return len;
551 }
552 BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
553 	      btrfs_discard_kbps_limit_store);
554 
btrfs_discard_max_discard_size_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)555 static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
556 						   struct kobj_attribute *a,
557 						   char *buf)
558 {
559 	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
560 
561 	return sysfs_emit(buf, "%llu\n",
562 			  READ_ONCE(fs_info->discard_ctl.max_discard_size));
563 }
564 
btrfs_discard_max_discard_size_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)565 static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
566 						    struct kobj_attribute *a,
567 						    const char *buf, size_t len)
568 {
569 	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
570 	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
571 	u64 max_discard_size;
572 	int ret;
573 
574 	ret = kstrtou64(buf, 10, &max_discard_size);
575 	if (ret)
576 		return -EINVAL;
577 
578 	WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
579 
580 	return len;
581 }
582 BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
583 	      btrfs_discard_max_discard_size_store);
584 
585 /*
586  * Per-filesystem stats for discard (when mounted with discard=async).
587  *
588  * Path: /sys/fs/btrfs/<uuid>/discard/
589  */
590 static const struct attribute *discard_attrs[] = {
591 	BTRFS_ATTR_PTR(discard, discardable_bytes),
592 	BTRFS_ATTR_PTR(discard, discardable_extents),
593 	BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
594 	BTRFS_ATTR_PTR(discard, discard_bytes_saved),
595 	BTRFS_ATTR_PTR(discard, discard_extent_bytes),
596 	BTRFS_ATTR_PTR(discard, iops_limit),
597 	BTRFS_ATTR_PTR(discard, kbps_limit),
598 	BTRFS_ATTR_PTR(discard, max_discard_size),
599 	NULL,
600 };
601 
602 #ifdef CONFIG_BTRFS_DEBUG
603 
604 /*
605  * Per-filesystem runtime debugging exported via sysfs.
606  *
607  * Path: /sys/fs/btrfs/UUID/debug/
608  */
609 static const struct attribute *btrfs_debug_mount_attrs[] = {
610 	NULL,
611 };
612 
613 /*
614  * Runtime debugging exported via sysfs, applies to all mounted filesystems.
615  *
616  * Path: /sys/fs/btrfs/debug
617  */
618 static struct attribute *btrfs_debug_feature_attrs[] = {
619 	NULL
620 };
621 
622 static const struct attribute_group btrfs_debug_feature_attr_group = {
623 	.name = "debug",
624 	.attrs = btrfs_debug_feature_attrs,
625 };
626 
627 #endif
628 
btrfs_show_u64(u64 * value_ptr,spinlock_t * lock,char * buf)629 static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
630 {
631 	u64 val;
632 	if (lock)
633 		spin_lock(lock);
634 	val = *value_ptr;
635 	if (lock)
636 		spin_unlock(lock);
637 	return sysfs_emit(buf, "%llu\n", val);
638 }
639 
global_rsv_size_show(struct kobject * kobj,struct kobj_attribute * ka,char * buf)640 static ssize_t global_rsv_size_show(struct kobject *kobj,
641 				    struct kobj_attribute *ka, char *buf)
642 {
643 	struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
644 	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
645 	return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
646 }
647 BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
648 
global_rsv_reserved_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)649 static ssize_t global_rsv_reserved_show(struct kobject *kobj,
650 					struct kobj_attribute *a, char *buf)
651 {
652 	struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
653 	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
654 	return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
655 }
656 BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
657 
658 #define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
659 #define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
660 
661 static ssize_t raid_bytes_show(struct kobject *kobj,
662 			       struct kobj_attribute *attr, char *buf);
663 BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
664 BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
665 
raid_bytes_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)666 static ssize_t raid_bytes_show(struct kobject *kobj,
667 			       struct kobj_attribute *attr, char *buf)
668 
669 {
670 	struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
671 	struct btrfs_block_group *block_group;
672 	int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
673 	u64 val = 0;
674 
675 	down_read(&sinfo->groups_sem);
676 	list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
677 		if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
678 			val += block_group->length;
679 		else
680 			val += block_group->used;
681 	}
682 	up_read(&sinfo->groups_sem);
683 	return sysfs_emit(buf, "%llu\n", val);
684 }
685 
686 /*
687  * Allocation information about block group profiles.
688  *
689  * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>/
690  */
691 static struct attribute *raid_attrs[] = {
692 	BTRFS_ATTR_PTR(raid, total_bytes),
693 	BTRFS_ATTR_PTR(raid, used_bytes),
694 	NULL
695 };
696 ATTRIBUTE_GROUPS(raid);
697 
release_raid_kobj(struct kobject * kobj)698 static void release_raid_kobj(struct kobject *kobj)
699 {
700 	kfree(to_raid_kobj(kobj));
701 }
702 
703 static struct kobj_type btrfs_raid_ktype = {
704 	.sysfs_ops = &kobj_sysfs_ops,
705 	.release = release_raid_kobj,
706 	.default_groups = raid_groups,
707 };
708 
709 #define SPACE_INFO_ATTR(field)						\
710 static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,	\
711 					     struct kobj_attribute *a,	\
712 					     char *buf)			\
713 {									\
714 	struct btrfs_space_info *sinfo = to_space_info(kobj);		\
715 	return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);	\
716 }									\
717 BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
718 
btrfs_chunk_size_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)719 static ssize_t btrfs_chunk_size_show(struct kobject *kobj,
720 				     struct kobj_attribute *a, char *buf)
721 {
722 	struct btrfs_space_info *sinfo = to_space_info(kobj);
723 
724 	return sysfs_emit(buf, "%llu\n", READ_ONCE(sinfo->chunk_size));
725 }
726 
727 /*
728  * Store new chunk size in space info. Can be called on a read-only filesystem.
729  *
730  * If the new chunk size value is larger than 10% of free space it is reduced
731  * to match that limit. Alignment must be to 256M and the system chunk size
732  * cannot be set.
733  */
btrfs_chunk_size_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)734 static ssize_t btrfs_chunk_size_store(struct kobject *kobj,
735 				      struct kobj_attribute *a,
736 				      const char *buf, size_t len)
737 {
738 	struct btrfs_space_info *space_info = to_space_info(kobj);
739 	struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
740 	char *retptr;
741 	u64 val;
742 
743 	if (!capable(CAP_SYS_ADMIN))
744 		return -EPERM;
745 
746 	if (!fs_info->fs_devices)
747 		return -EINVAL;
748 
749 	if (btrfs_is_zoned(fs_info))
750 		return -EINVAL;
751 
752 	/* System block type must not be changed. */
753 	if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM)
754 		return -EPERM;
755 
756 	val = memparse(buf, &retptr);
757 	/* There could be trailing '\n', also catch any typos after the value */
758 	retptr = skip_spaces(retptr);
759 	if (*retptr != 0 || val == 0)
760 		return -EINVAL;
761 
762 	val = min(val, BTRFS_MAX_DATA_CHUNK_SIZE);
763 
764 	/* Limit stripe size to 10% of available space. */
765 	val = min(div_factor(fs_info->fs_devices->total_rw_bytes, 1), val);
766 
767 	/* Must be multiple of 256M. */
768 	val &= ~((u64)SZ_256M - 1);
769 
770 	/* Must be at least 256M. */
771 	if (val < SZ_256M)
772 		return -EINVAL;
773 
774 	btrfs_update_space_info_chunk_size(space_info, val);
775 
776 	return len;
777 }
778 
779 #ifdef CONFIG_BTRFS_DEBUG
780 /*
781  * Request chunk allocation with current chunk size.
782  */
btrfs_force_chunk_alloc_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)783 static ssize_t btrfs_force_chunk_alloc_store(struct kobject *kobj,
784 					     struct kobj_attribute *a,
785 					     const char *buf, size_t len)
786 {
787 	struct btrfs_space_info *space_info = to_space_info(kobj);
788 	struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
789 	struct btrfs_trans_handle *trans;
790 	bool val;
791 	int ret;
792 
793 	if (!capable(CAP_SYS_ADMIN))
794 		return -EPERM;
795 
796 	if (sb_rdonly(fs_info->sb))
797 		return -EROFS;
798 
799 	ret = kstrtobool(buf, &val);
800 	if (ret)
801 		return ret;
802 
803 	if (!val)
804 		return -EINVAL;
805 
806 	/*
807 	 * This is unsafe to be called from sysfs context and may cause
808 	 * unexpected problems.
809 	 */
810 	trans = btrfs_start_transaction(fs_info->tree_root, 0);
811 	if (IS_ERR(trans))
812 		return PTR_ERR(trans);
813 	ret = btrfs_force_chunk_alloc(trans, space_info->flags);
814 	btrfs_end_transaction(trans);
815 
816 	if (ret == 1)
817 		return len;
818 
819 	return -ENOSPC;
820 }
821 BTRFS_ATTR_W(space_info, force_chunk_alloc, btrfs_force_chunk_alloc_store);
822 
823 #endif
824 
825 SPACE_INFO_ATTR(flags);
826 SPACE_INFO_ATTR(total_bytes);
827 SPACE_INFO_ATTR(bytes_used);
828 SPACE_INFO_ATTR(bytes_pinned);
829 SPACE_INFO_ATTR(bytes_reserved);
830 SPACE_INFO_ATTR(bytes_may_use);
831 SPACE_INFO_ATTR(bytes_readonly);
832 SPACE_INFO_ATTR(bytes_zone_unusable);
833 SPACE_INFO_ATTR(disk_used);
834 SPACE_INFO_ATTR(disk_total);
835 BTRFS_ATTR_RW(space_info, chunk_size, btrfs_chunk_size_show, btrfs_chunk_size_store);
836 
btrfs_sinfo_bg_reclaim_threshold_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)837 static ssize_t btrfs_sinfo_bg_reclaim_threshold_show(struct kobject *kobj,
838 						     struct kobj_attribute *a,
839 						     char *buf)
840 {
841 	struct btrfs_space_info *space_info = to_space_info(kobj);
842 
843 	return sysfs_emit(buf, "%d\n", READ_ONCE(space_info->bg_reclaim_threshold));
844 }
845 
btrfs_sinfo_bg_reclaim_threshold_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)846 static ssize_t btrfs_sinfo_bg_reclaim_threshold_store(struct kobject *kobj,
847 						      struct kobj_attribute *a,
848 						      const char *buf, size_t len)
849 {
850 	struct btrfs_space_info *space_info = to_space_info(kobj);
851 	int thresh;
852 	int ret;
853 
854 	ret = kstrtoint(buf, 10, &thresh);
855 	if (ret)
856 		return ret;
857 
858 	if (thresh < 0 || thresh > 100)
859 		return -EINVAL;
860 
861 	WRITE_ONCE(space_info->bg_reclaim_threshold, thresh);
862 
863 	return len;
864 }
865 
866 BTRFS_ATTR_RW(space_info, bg_reclaim_threshold,
867 	      btrfs_sinfo_bg_reclaim_threshold_show,
868 	      btrfs_sinfo_bg_reclaim_threshold_store);
869 
870 /*
871  * Allocation information about block group types.
872  *
873  * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/
874  */
875 static struct attribute *space_info_attrs[] = {
876 	BTRFS_ATTR_PTR(space_info, flags),
877 	BTRFS_ATTR_PTR(space_info, total_bytes),
878 	BTRFS_ATTR_PTR(space_info, bytes_used),
879 	BTRFS_ATTR_PTR(space_info, bytes_pinned),
880 	BTRFS_ATTR_PTR(space_info, bytes_reserved),
881 	BTRFS_ATTR_PTR(space_info, bytes_may_use),
882 	BTRFS_ATTR_PTR(space_info, bytes_readonly),
883 	BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
884 	BTRFS_ATTR_PTR(space_info, disk_used),
885 	BTRFS_ATTR_PTR(space_info, disk_total),
886 	BTRFS_ATTR_PTR(space_info, bg_reclaim_threshold),
887 	BTRFS_ATTR_PTR(space_info, chunk_size),
888 #ifdef CONFIG_BTRFS_DEBUG
889 	BTRFS_ATTR_PTR(space_info, force_chunk_alloc),
890 #endif
891 	NULL,
892 };
893 ATTRIBUTE_GROUPS(space_info);
894 
space_info_release(struct kobject * kobj)895 static void space_info_release(struct kobject *kobj)
896 {
897 	struct btrfs_space_info *sinfo = to_space_info(kobj);
898 	kfree(sinfo);
899 }
900 
901 static struct kobj_type space_info_ktype = {
902 	.sysfs_ops = &kobj_sysfs_ops,
903 	.release = space_info_release,
904 	.default_groups = space_info_groups,
905 };
906 
907 /*
908  * Allocation information about block groups.
909  *
910  * Path: /sys/fs/btrfs/<uuid>/allocation/
911  */
912 static const struct attribute *allocation_attrs[] = {
913 	BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
914 	BTRFS_ATTR_PTR(allocation, global_rsv_size),
915 	NULL,
916 };
917 
btrfs_label_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)918 static ssize_t btrfs_label_show(struct kobject *kobj,
919 				struct kobj_attribute *a, char *buf)
920 {
921 	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
922 	char *label = fs_info->super_copy->label;
923 	ssize_t ret;
924 
925 	spin_lock(&fs_info->super_lock);
926 	ret = sysfs_emit(buf, label[0] ? "%s\n" : "%s", label);
927 	spin_unlock(&fs_info->super_lock);
928 
929 	return ret;
930 }
931 
btrfs_label_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)932 static ssize_t btrfs_label_store(struct kobject *kobj,
933 				 struct kobj_attribute *a,
934 				 const char *buf, size_t len)
935 {
936 	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
937 	size_t p_len;
938 
939 	if (!fs_info)
940 		return -EPERM;
941 
942 	if (sb_rdonly(fs_info->sb))
943 		return -EROFS;
944 
945 	/*
946 	 * p_len is the len until the first occurrence of either
947 	 * '\n' or '\0'
948 	 */
949 	p_len = strcspn(buf, "\n");
950 
951 	if (p_len >= BTRFS_LABEL_SIZE)
952 		return -EINVAL;
953 
954 	spin_lock(&fs_info->super_lock);
955 	memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
956 	memcpy(fs_info->super_copy->label, buf, p_len);
957 	spin_unlock(&fs_info->super_lock);
958 
959 	/*
960 	 * We don't want to do full transaction commit from inside sysfs
961 	 */
962 	btrfs_set_pending(fs_info, COMMIT);
963 	wake_up_process(fs_info->transaction_kthread);
964 
965 	return len;
966 }
967 BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
968 
btrfs_nodesize_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)969 static ssize_t btrfs_nodesize_show(struct kobject *kobj,
970 				struct kobj_attribute *a, char *buf)
971 {
972 	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
973 
974 	return sysfs_emit(buf, "%u\n", fs_info->super_copy->nodesize);
975 }
976 
977 BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
978 
btrfs_sectorsize_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)979 static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
980 				struct kobj_attribute *a, char *buf)
981 {
982 	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
983 
984 	return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
985 }
986 
987 BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
988 
btrfs_commit_stats_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)989 static ssize_t btrfs_commit_stats_show(struct kobject *kobj,
990 				       struct kobj_attribute *a, char *buf)
991 {
992 	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
993 
994 	return sysfs_emit(buf,
995 		"commits %llu\n"
996 		"last_commit_ms %llu\n"
997 		"max_commit_ms %llu\n"
998 		"total_commit_ms %llu\n",
999 		fs_info->commit_stats.commit_count,
1000 		div_u64(fs_info->commit_stats.last_commit_dur, NSEC_PER_MSEC),
1001 		div_u64(fs_info->commit_stats.max_commit_dur, NSEC_PER_MSEC),
1002 		div_u64(fs_info->commit_stats.total_commit_dur, NSEC_PER_MSEC));
1003 }
1004 
btrfs_commit_stats_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)1005 static ssize_t btrfs_commit_stats_store(struct kobject *kobj,
1006 					struct kobj_attribute *a,
1007 					const char *buf, size_t len)
1008 {
1009 	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1010 	unsigned long val;
1011 	int ret;
1012 
1013 	if (!fs_info)
1014 		return -EPERM;
1015 
1016 	if (!capable(CAP_SYS_RESOURCE))
1017 		return -EPERM;
1018 
1019 	ret = kstrtoul(buf, 10, &val);
1020 	if (ret)
1021 		return ret;
1022 	if (val)
1023 		return -EINVAL;
1024 
1025 	WRITE_ONCE(fs_info->commit_stats.max_commit_dur, 0);
1026 
1027 	return len;
1028 }
1029 BTRFS_ATTR_RW(, commit_stats, btrfs_commit_stats_show, btrfs_commit_stats_store);
1030 
btrfs_clone_alignment_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1031 static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
1032 				struct kobj_attribute *a, char *buf)
1033 {
1034 	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1035 
1036 	return sysfs_emit(buf, "%u\n", fs_info->super_copy->sectorsize);
1037 }
1038 
1039 BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
1040 
quota_override_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1041 static ssize_t quota_override_show(struct kobject *kobj,
1042 				   struct kobj_attribute *a, char *buf)
1043 {
1044 	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1045 	int quota_override;
1046 
1047 	quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1048 	return sysfs_emit(buf, "%d\n", quota_override);
1049 }
1050 
quota_override_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)1051 static ssize_t quota_override_store(struct kobject *kobj,
1052 				    struct kobj_attribute *a,
1053 				    const char *buf, size_t len)
1054 {
1055 	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1056 	unsigned long knob;
1057 	int err;
1058 
1059 	if (!fs_info)
1060 		return -EPERM;
1061 
1062 	if (!capable(CAP_SYS_RESOURCE))
1063 		return -EPERM;
1064 
1065 	err = kstrtoul(buf, 10, &knob);
1066 	if (err)
1067 		return err;
1068 	if (knob > 1)
1069 		return -EINVAL;
1070 
1071 	if (knob)
1072 		set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1073 	else
1074 		clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1075 
1076 	return len;
1077 }
1078 
1079 BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
1080 
btrfs_metadata_uuid_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1081 static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
1082 				struct kobj_attribute *a, char *buf)
1083 {
1084 	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1085 
1086 	return sysfs_emit(buf, "%pU\n", fs_info->fs_devices->metadata_uuid);
1087 }
1088 
1089 BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
1090 
btrfs_checksum_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1091 static ssize_t btrfs_checksum_show(struct kobject *kobj,
1092 				   struct kobj_attribute *a, char *buf)
1093 {
1094 	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1095 	u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
1096 
1097 	return sysfs_emit(buf, "%s (%s)\n",
1098 			  btrfs_super_csum_name(csum_type),
1099 			  crypto_shash_driver_name(fs_info->csum_shash));
1100 }
1101 
1102 BTRFS_ATTR(, checksum, btrfs_checksum_show);
1103 
btrfs_exclusive_operation_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1104 static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
1105 		struct kobj_attribute *a, char *buf)
1106 {
1107 	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1108 	const char *str;
1109 
1110 	switch (READ_ONCE(fs_info->exclusive_operation)) {
1111 		case  BTRFS_EXCLOP_NONE:
1112 			str = "none\n";
1113 			break;
1114 		case BTRFS_EXCLOP_BALANCE:
1115 			str = "balance\n";
1116 			break;
1117 		case BTRFS_EXCLOP_BALANCE_PAUSED:
1118 			str = "balance paused\n";
1119 			break;
1120 		case BTRFS_EXCLOP_DEV_ADD:
1121 			str = "device add\n";
1122 			break;
1123 		case BTRFS_EXCLOP_DEV_REMOVE:
1124 			str = "device remove\n";
1125 			break;
1126 		case BTRFS_EXCLOP_DEV_REPLACE:
1127 			str = "device replace\n";
1128 			break;
1129 		case BTRFS_EXCLOP_RESIZE:
1130 			str = "resize\n";
1131 			break;
1132 		case BTRFS_EXCLOP_SWAP_ACTIVATE:
1133 			str = "swap activate\n";
1134 			break;
1135 		default:
1136 			str = "UNKNOWN\n";
1137 			break;
1138 	}
1139 	return sysfs_emit(buf, "%s", str);
1140 }
1141 BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
1142 
btrfs_generation_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1143 static ssize_t btrfs_generation_show(struct kobject *kobj,
1144 				     struct kobj_attribute *a, char *buf)
1145 {
1146 	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1147 
1148 	return sysfs_emit(buf, "%llu\n", fs_info->generation);
1149 }
1150 BTRFS_ATTR(, generation, btrfs_generation_show);
1151 
1152 static const char * const btrfs_read_policy_name[] = { "pid" };
1153 
btrfs_read_policy_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1154 static ssize_t btrfs_read_policy_show(struct kobject *kobj,
1155 				      struct kobj_attribute *a, char *buf)
1156 {
1157 	struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1158 	ssize_t ret = 0;
1159 	int i;
1160 
1161 	for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1162 		if (fs_devices->read_policy == i)
1163 			ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s[%s]",
1164 					 (ret == 0 ? "" : " "),
1165 					 btrfs_read_policy_name[i]);
1166 		else
1167 			ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
1168 					 (ret == 0 ? "" : " "),
1169 					 btrfs_read_policy_name[i]);
1170 	}
1171 
1172 	ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
1173 
1174 	return ret;
1175 }
1176 
btrfs_read_policy_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)1177 static ssize_t btrfs_read_policy_store(struct kobject *kobj,
1178 				       struct kobj_attribute *a,
1179 				       const char *buf, size_t len)
1180 {
1181 	struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1182 	int i;
1183 
1184 	for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1185 		if (sysfs_streq(buf, btrfs_read_policy_name[i])) {
1186 			if (i != fs_devices->read_policy) {
1187 				fs_devices->read_policy = i;
1188 				btrfs_info(fs_devices->fs_info,
1189 					   "read policy set to '%s'",
1190 					   btrfs_read_policy_name[i]);
1191 			}
1192 			return len;
1193 		}
1194 	}
1195 
1196 	return -EINVAL;
1197 }
1198 BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
1199 
btrfs_bg_reclaim_threshold_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1200 static ssize_t btrfs_bg_reclaim_threshold_show(struct kobject *kobj,
1201 					       struct kobj_attribute *a,
1202 					       char *buf)
1203 {
1204 	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1205 
1206 	return sysfs_emit(buf, "%d\n", READ_ONCE(fs_info->bg_reclaim_threshold));
1207 }
1208 
btrfs_bg_reclaim_threshold_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)1209 static ssize_t btrfs_bg_reclaim_threshold_store(struct kobject *kobj,
1210 						struct kobj_attribute *a,
1211 						const char *buf, size_t len)
1212 {
1213 	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1214 	int thresh;
1215 	int ret;
1216 
1217 	ret = kstrtoint(buf, 10, &thresh);
1218 	if (ret)
1219 		return ret;
1220 
1221 	if (thresh != 0 && (thresh <= 50 || thresh > 100))
1222 		return -EINVAL;
1223 
1224 	WRITE_ONCE(fs_info->bg_reclaim_threshold, thresh);
1225 
1226 	return len;
1227 }
1228 BTRFS_ATTR_RW(, bg_reclaim_threshold, btrfs_bg_reclaim_threshold_show,
1229 	      btrfs_bg_reclaim_threshold_store);
1230 
1231 /*
1232  * Per-filesystem information and stats.
1233  *
1234  * Path: /sys/fs/btrfs/<uuid>/
1235  */
1236 static const struct attribute *btrfs_attrs[] = {
1237 	BTRFS_ATTR_PTR(, label),
1238 	BTRFS_ATTR_PTR(, nodesize),
1239 	BTRFS_ATTR_PTR(, sectorsize),
1240 	BTRFS_ATTR_PTR(, clone_alignment),
1241 	BTRFS_ATTR_PTR(, quota_override),
1242 	BTRFS_ATTR_PTR(, metadata_uuid),
1243 	BTRFS_ATTR_PTR(, checksum),
1244 	BTRFS_ATTR_PTR(, exclusive_operation),
1245 	BTRFS_ATTR_PTR(, generation),
1246 	BTRFS_ATTR_PTR(, read_policy),
1247 	BTRFS_ATTR_PTR(, bg_reclaim_threshold),
1248 	BTRFS_ATTR_PTR(, commit_stats),
1249 	NULL,
1250 };
1251 
btrfs_release_fsid_kobj(struct kobject * kobj)1252 static void btrfs_release_fsid_kobj(struct kobject *kobj)
1253 {
1254 	struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
1255 
1256 	memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
1257 	complete(&fs_devs->kobj_unregister);
1258 }
1259 
1260 static struct kobj_type btrfs_ktype = {
1261 	.sysfs_ops	= &kobj_sysfs_ops,
1262 	.release	= btrfs_release_fsid_kobj,
1263 };
1264 
to_fs_devs(struct kobject * kobj)1265 static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
1266 {
1267 	if (kobj->ktype != &btrfs_ktype)
1268 		return NULL;
1269 	return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
1270 }
1271 
to_fs_info(struct kobject * kobj)1272 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
1273 {
1274 	if (kobj->ktype != &btrfs_ktype)
1275 		return NULL;
1276 	return to_fs_devs(kobj)->fs_info;
1277 }
1278 
get_btrfs_kobj(struct kobject * kobj)1279 static struct kobject *get_btrfs_kobj(struct kobject *kobj)
1280 {
1281 	while (kobj) {
1282 		if (kobj->ktype == &btrfs_ktype)
1283 			return kobj;
1284 		kobj = kobj->parent;
1285 	}
1286 	return NULL;
1287 }
1288 
1289 #define NUM_FEATURE_BITS 64
1290 #define BTRFS_FEATURE_NAME_MAX 13
1291 static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
1292 static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
1293 
1294 static_assert(ARRAY_SIZE(btrfs_unknown_feature_names) ==
1295 	      ARRAY_SIZE(btrfs_feature_attrs));
1296 static_assert(ARRAY_SIZE(btrfs_unknown_feature_names[0]) ==
1297 	      ARRAY_SIZE(btrfs_feature_attrs[0]));
1298 
1299 static const u64 supported_feature_masks[FEAT_MAX] = {
1300 	[FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
1301 	[FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
1302 	[FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
1303 };
1304 
addrm_unknown_feature_attrs(struct btrfs_fs_info * fs_info,bool add)1305 static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
1306 {
1307 	int set;
1308 
1309 	for (set = 0; set < FEAT_MAX; set++) {
1310 		int i;
1311 		struct attribute *attrs[2];
1312 		struct attribute_group agroup = {
1313 			.name = "features",
1314 			.attrs = attrs,
1315 		};
1316 		u64 features = get_features(fs_info, set);
1317 		features &= ~supported_feature_masks[set];
1318 
1319 		if (!features)
1320 			continue;
1321 
1322 		attrs[1] = NULL;
1323 		for (i = 0; i < NUM_FEATURE_BITS; i++) {
1324 			struct btrfs_feature_attr *fa;
1325 
1326 			if (!(features & (1ULL << i)))
1327 				continue;
1328 
1329 			fa = &btrfs_feature_attrs[set][i];
1330 			attrs[0] = &fa->kobj_attr.attr;
1331 			if (add) {
1332 				int ret;
1333 				ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
1334 							&agroup);
1335 				if (ret)
1336 					return ret;
1337 			} else
1338 				sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
1339 						    &agroup);
1340 		}
1341 
1342 	}
1343 	return 0;
1344 }
1345 
__btrfs_sysfs_remove_fsid(struct btrfs_fs_devices * fs_devs)1346 static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1347 {
1348 	if (fs_devs->devinfo_kobj) {
1349 		kobject_del(fs_devs->devinfo_kobj);
1350 		kobject_put(fs_devs->devinfo_kobj);
1351 		fs_devs->devinfo_kobj = NULL;
1352 	}
1353 
1354 	if (fs_devs->devices_kobj) {
1355 		kobject_del(fs_devs->devices_kobj);
1356 		kobject_put(fs_devs->devices_kobj);
1357 		fs_devs->devices_kobj = NULL;
1358 	}
1359 
1360 	if (fs_devs->fsid_kobj.state_initialized) {
1361 		kobject_del(&fs_devs->fsid_kobj);
1362 		kobject_put(&fs_devs->fsid_kobj);
1363 		wait_for_completion(&fs_devs->kobj_unregister);
1364 	}
1365 }
1366 
1367 /* when fs_devs is NULL it will remove all fsid kobject */
btrfs_sysfs_remove_fsid(struct btrfs_fs_devices * fs_devs)1368 void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1369 {
1370 	struct list_head *fs_uuids = btrfs_get_fs_uuids();
1371 
1372 	if (fs_devs) {
1373 		__btrfs_sysfs_remove_fsid(fs_devs);
1374 		return;
1375 	}
1376 
1377 	list_for_each_entry(fs_devs, fs_uuids, fs_list) {
1378 		__btrfs_sysfs_remove_fsid(fs_devs);
1379 	}
1380 }
1381 
btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices * fs_devices)1382 static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
1383 {
1384 	struct btrfs_device *device;
1385 	struct btrfs_fs_devices *seed;
1386 
1387 	list_for_each_entry(device, &fs_devices->devices, dev_list)
1388 		btrfs_sysfs_remove_device(device);
1389 
1390 	list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1391 		list_for_each_entry(device, &seed->devices, dev_list)
1392 			btrfs_sysfs_remove_device(device);
1393 	}
1394 }
1395 
btrfs_sysfs_remove_mounted(struct btrfs_fs_info * fs_info)1396 void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
1397 {
1398 	struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1399 
1400 	sysfs_remove_link(fsid_kobj, "bdi");
1401 
1402 	if (fs_info->space_info_kobj) {
1403 		sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
1404 		kobject_del(fs_info->space_info_kobj);
1405 		kobject_put(fs_info->space_info_kobj);
1406 	}
1407 	if (fs_info->discard_kobj) {
1408 		sysfs_remove_files(fs_info->discard_kobj, discard_attrs);
1409 		kobject_del(fs_info->discard_kobj);
1410 		kobject_put(fs_info->discard_kobj);
1411 	}
1412 #ifdef CONFIG_BTRFS_DEBUG
1413 	if (fs_info->debug_kobj) {
1414 		sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1415 		kobject_del(fs_info->debug_kobj);
1416 		kobject_put(fs_info->debug_kobj);
1417 	}
1418 #endif
1419 	addrm_unknown_feature_attrs(fs_info, false);
1420 	sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1421 	sysfs_remove_files(fsid_kobj, btrfs_attrs);
1422 	btrfs_sysfs_remove_fs_devices(fs_info->fs_devices);
1423 }
1424 
1425 static const char * const btrfs_feature_set_names[FEAT_MAX] = {
1426 	[FEAT_COMPAT]	 = "compat",
1427 	[FEAT_COMPAT_RO] = "compat_ro",
1428 	[FEAT_INCOMPAT]	 = "incompat",
1429 };
1430 
btrfs_feature_set_name(enum btrfs_feature_set set)1431 const char *btrfs_feature_set_name(enum btrfs_feature_set set)
1432 {
1433 	return btrfs_feature_set_names[set];
1434 }
1435 
btrfs_printable_features(enum btrfs_feature_set set,u64 flags)1436 char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
1437 {
1438 	size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
1439 	int len = 0;
1440 	int i;
1441 	char *str;
1442 
1443 	str = kmalloc(bufsize, GFP_KERNEL);
1444 	if (!str)
1445 		return str;
1446 
1447 	for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1448 		const char *name;
1449 
1450 		if (!(flags & (1ULL << i)))
1451 			continue;
1452 
1453 		name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
1454 		len += scnprintf(str + len, bufsize - len, "%s%s",
1455 				len ? "," : "", name);
1456 	}
1457 
1458 	return str;
1459 }
1460 
init_feature_attrs(void)1461 static void init_feature_attrs(void)
1462 {
1463 	struct btrfs_feature_attr *fa;
1464 	int set, i;
1465 
1466 	memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1467 	memset(btrfs_unknown_feature_names, 0,
1468 	       sizeof(btrfs_unknown_feature_names));
1469 
1470 	for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1471 		struct btrfs_feature_attr *sfa;
1472 		struct attribute *a = btrfs_supported_feature_attrs[i];
1473 		int bit;
1474 		sfa = attr_to_btrfs_feature_attr(a);
1475 		bit = ilog2(sfa->feature_bit);
1476 		fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1477 
1478 		fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1479 	}
1480 
1481 	for (set = 0; set < FEAT_MAX; set++) {
1482 		for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1483 			char *name = btrfs_unknown_feature_names[set][i];
1484 			fa = &btrfs_feature_attrs[set][i];
1485 
1486 			if (fa->kobj_attr.attr.name)
1487 				continue;
1488 
1489 			snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
1490 				 btrfs_feature_set_names[set], i);
1491 
1492 			fa->kobj_attr.attr.name = name;
1493 			fa->kobj_attr.attr.mode = S_IRUGO;
1494 			fa->feature_set = set;
1495 			fa->feature_bit = 1ULL << i;
1496 		}
1497 	}
1498 }
1499 
1500 /*
1501  * Create a sysfs entry for a given block group type at path
1502  * /sys/fs/btrfs/UUID/allocation/data/TYPE
1503  */
btrfs_sysfs_add_block_group_type(struct btrfs_block_group * cache)1504 void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1505 {
1506 	struct btrfs_fs_info *fs_info = cache->fs_info;
1507 	struct btrfs_space_info *space_info = cache->space_info;
1508 	struct raid_kobject *rkobj;
1509 	const int index = btrfs_bg_flags_to_raid_index(cache->flags);
1510 	unsigned int nofs_flag;
1511 	int ret;
1512 
1513 	/*
1514 	 * Setup a NOFS context because kobject_add(), deep in its call chain,
1515 	 * does GFP_KERNEL allocations, and we are often called in a context
1516 	 * where if reclaim is triggered we can deadlock (we are either holding
1517 	 * a transaction handle or some lock required for a transaction
1518 	 * commit).
1519 	 */
1520 	nofs_flag = memalloc_nofs_save();
1521 
1522 	rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1523 	if (!rkobj) {
1524 		memalloc_nofs_restore(nofs_flag);
1525 		btrfs_warn(cache->fs_info,
1526 				"couldn't alloc memory for raid level kobject");
1527 		return;
1528 	}
1529 
1530 	rkobj->flags = cache->flags;
1531 	kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1532 
1533 	/*
1534 	 * We call this either on mount, or if we've created a block group for a
1535 	 * new index type while running (i.e. when restriping).  The running
1536 	 * case is tricky because we could race with other threads, so we need
1537 	 * to have this check to make sure we didn't already init the kobject.
1538 	 *
1539 	 * We don't have to protect on the free side because it only happens on
1540 	 * unmount.
1541 	 */
1542 	spin_lock(&space_info->lock);
1543 	if (space_info->block_group_kobjs[index]) {
1544 		spin_unlock(&space_info->lock);
1545 		kobject_put(&rkobj->kobj);
1546 		return;
1547 	} else {
1548 		space_info->block_group_kobjs[index] = &rkobj->kobj;
1549 	}
1550 	spin_unlock(&space_info->lock);
1551 
1552 	ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1553 			  btrfs_bg_type_to_raid_name(rkobj->flags));
1554 	memalloc_nofs_restore(nofs_flag);
1555 	if (ret) {
1556 		spin_lock(&space_info->lock);
1557 		space_info->block_group_kobjs[index] = NULL;
1558 		spin_unlock(&space_info->lock);
1559 		kobject_put(&rkobj->kobj);
1560 		btrfs_warn(fs_info,
1561 			"failed to add kobject for block cache, ignoring");
1562 		return;
1563 	}
1564 }
1565 
1566 /*
1567  * Remove sysfs directories for all block group types of a given space info and
1568  * the space info as well
1569  */
btrfs_sysfs_remove_space_info(struct btrfs_space_info * space_info)1570 void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1571 {
1572 	int i;
1573 
1574 	for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1575 		struct kobject *kobj;
1576 
1577 		kobj = space_info->block_group_kobjs[i];
1578 		space_info->block_group_kobjs[i] = NULL;
1579 		if (kobj) {
1580 			kobject_del(kobj);
1581 			kobject_put(kobj);
1582 		}
1583 	}
1584 	kobject_del(&space_info->kobj);
1585 	kobject_put(&space_info->kobj);
1586 }
1587 
alloc_name(u64 flags)1588 static const char *alloc_name(u64 flags)
1589 {
1590 	switch (flags) {
1591 	case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1592 		return "mixed";
1593 	case BTRFS_BLOCK_GROUP_METADATA:
1594 		return "metadata";
1595 	case BTRFS_BLOCK_GROUP_DATA:
1596 		return "data";
1597 	case BTRFS_BLOCK_GROUP_SYSTEM:
1598 		return "system";
1599 	default:
1600 		WARN_ON(1);
1601 		return "invalid-combination";
1602 	}
1603 }
1604 
1605 /*
1606  * Create a sysfs entry for a space info type at path
1607  * /sys/fs/btrfs/UUID/allocation/TYPE
1608  */
btrfs_sysfs_add_space_info_type(struct btrfs_fs_info * fs_info,struct btrfs_space_info * space_info)1609 int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1610 				    struct btrfs_space_info *space_info)
1611 {
1612 	int ret;
1613 
1614 	ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1615 				   fs_info->space_info_kobj, "%s",
1616 				   alloc_name(space_info->flags));
1617 	if (ret) {
1618 		kobject_put(&space_info->kobj);
1619 		return ret;
1620 	}
1621 
1622 	return 0;
1623 }
1624 
btrfs_sysfs_remove_device(struct btrfs_device * device)1625 void btrfs_sysfs_remove_device(struct btrfs_device *device)
1626 {
1627 	struct kobject *devices_kobj;
1628 
1629 	/*
1630 	 * Seed fs_devices devices_kobj aren't used, fetch kobject from the
1631 	 * fs_info::fs_devices.
1632 	 */
1633 	devices_kobj = device->fs_info->fs_devices->devices_kobj;
1634 	ASSERT(devices_kobj);
1635 
1636 	if (device->bdev)
1637 		sysfs_remove_link(devices_kobj, bdev_kobj(device->bdev)->name);
1638 
1639 	if (device->devid_kobj.state_initialized) {
1640 		kobject_del(&device->devid_kobj);
1641 		kobject_put(&device->devid_kobj);
1642 		wait_for_completion(&device->kobj_unregister);
1643 	}
1644 }
1645 
btrfs_devinfo_in_fs_metadata_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1646 static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1647 					         struct kobj_attribute *a,
1648 					         char *buf)
1649 {
1650 	int val;
1651 	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1652 						   devid_kobj);
1653 
1654 	val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1655 
1656 	return sysfs_emit(buf, "%d\n", val);
1657 }
1658 BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1659 
btrfs_devinfo_missing_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1660 static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1661 					struct kobj_attribute *a, char *buf)
1662 {
1663 	int val;
1664 	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1665 						   devid_kobj);
1666 
1667 	val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1668 
1669 	return sysfs_emit(buf, "%d\n", val);
1670 }
1671 BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1672 
btrfs_devinfo_replace_target_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1673 static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1674 					         struct kobj_attribute *a,
1675 					         char *buf)
1676 {
1677 	int val;
1678 	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1679 						   devid_kobj);
1680 
1681 	val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1682 
1683 	return sysfs_emit(buf, "%d\n", val);
1684 }
1685 BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1686 
btrfs_devinfo_scrub_speed_max_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1687 static ssize_t btrfs_devinfo_scrub_speed_max_show(struct kobject *kobj,
1688 					     struct kobj_attribute *a,
1689 					     char *buf)
1690 {
1691 	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1692 						   devid_kobj);
1693 
1694 	return sysfs_emit(buf, "%llu\n", READ_ONCE(device->scrub_speed_max));
1695 }
1696 
btrfs_devinfo_scrub_speed_max_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)1697 static ssize_t btrfs_devinfo_scrub_speed_max_store(struct kobject *kobj,
1698 					      struct kobj_attribute *a,
1699 					      const char *buf, size_t len)
1700 {
1701 	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1702 						   devid_kobj);
1703 	char *endptr;
1704 	unsigned long long limit;
1705 
1706 	limit = memparse(buf, &endptr);
1707 	WRITE_ONCE(device->scrub_speed_max, limit);
1708 	return len;
1709 }
1710 BTRFS_ATTR_RW(devid, scrub_speed_max, btrfs_devinfo_scrub_speed_max_show,
1711 	      btrfs_devinfo_scrub_speed_max_store);
1712 
btrfs_devinfo_writeable_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1713 static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1714 					    struct kobj_attribute *a, char *buf)
1715 {
1716 	int val;
1717 	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1718 						   devid_kobj);
1719 
1720 	val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1721 
1722 	return sysfs_emit(buf, "%d\n", val);
1723 }
1724 BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1725 
btrfs_devinfo_fsid_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1726 static ssize_t btrfs_devinfo_fsid_show(struct kobject *kobj,
1727 				       struct kobj_attribute *a, char *buf)
1728 {
1729 	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1730 						   devid_kobj);
1731 
1732 	return sysfs_emit(buf, "%pU\n", device->fs_devices->fsid);
1733 }
1734 BTRFS_ATTR(devid, fsid, btrfs_devinfo_fsid_show);
1735 
btrfs_devinfo_error_stats_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1736 static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj,
1737 		struct kobj_attribute *a, char *buf)
1738 {
1739 	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1740 						   devid_kobj);
1741 
1742 	if (!device->dev_stats_valid)
1743 		return sysfs_emit(buf, "invalid\n");
1744 
1745 	/*
1746 	 * Print all at once so we get a snapshot of all values from the same
1747 	 * time. Keep them in sync and in order of definition of
1748 	 * btrfs_dev_stat_values.
1749 	 */
1750 	return sysfs_emit(buf,
1751 		"write_errs %d\n"
1752 		"read_errs %d\n"
1753 		"flush_errs %d\n"
1754 		"corruption_errs %d\n"
1755 		"generation_errs %d\n",
1756 		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_WRITE_ERRS),
1757 		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_READ_ERRS),
1758 		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_FLUSH_ERRS),
1759 		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_CORRUPTION_ERRS),
1760 		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_GENERATION_ERRS));
1761 }
1762 BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show);
1763 
1764 /*
1765  * Information about one device.
1766  *
1767  * Path: /sys/fs/btrfs/<uuid>/devinfo/<devid>/
1768  */
1769 static struct attribute *devid_attrs[] = {
1770 	BTRFS_ATTR_PTR(devid, error_stats),
1771 	BTRFS_ATTR_PTR(devid, fsid),
1772 	BTRFS_ATTR_PTR(devid, in_fs_metadata),
1773 	BTRFS_ATTR_PTR(devid, missing),
1774 	BTRFS_ATTR_PTR(devid, replace_target),
1775 	BTRFS_ATTR_PTR(devid, scrub_speed_max),
1776 	BTRFS_ATTR_PTR(devid, writeable),
1777 	NULL
1778 };
1779 ATTRIBUTE_GROUPS(devid);
1780 
btrfs_release_devid_kobj(struct kobject * kobj)1781 static void btrfs_release_devid_kobj(struct kobject *kobj)
1782 {
1783 	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1784 						   devid_kobj);
1785 
1786 	memset(&device->devid_kobj, 0, sizeof(struct kobject));
1787 	complete(&device->kobj_unregister);
1788 }
1789 
1790 static struct kobj_type devid_ktype = {
1791 	.sysfs_ops	= &kobj_sysfs_ops,
1792 	.default_groups = devid_groups,
1793 	.release	= btrfs_release_devid_kobj,
1794 };
1795 
btrfs_sysfs_add_device(struct btrfs_device * device)1796 int btrfs_sysfs_add_device(struct btrfs_device *device)
1797 {
1798 	int ret;
1799 	unsigned int nofs_flag;
1800 	struct kobject *devices_kobj;
1801 	struct kobject *devinfo_kobj;
1802 
1803 	/*
1804 	 * Make sure we use the fs_info::fs_devices to fetch the kobjects even
1805 	 * for the seed fs_devices
1806 	 */
1807 	devices_kobj = device->fs_info->fs_devices->devices_kobj;
1808 	devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
1809 	ASSERT(devices_kobj);
1810 	ASSERT(devinfo_kobj);
1811 
1812 	nofs_flag = memalloc_nofs_save();
1813 
1814 	if (device->bdev) {
1815 		struct kobject *disk_kobj = bdev_kobj(device->bdev);
1816 
1817 		ret = sysfs_create_link(devices_kobj, disk_kobj, disk_kobj->name);
1818 		if (ret) {
1819 			btrfs_warn(device->fs_info,
1820 				"creating sysfs device link for devid %llu failed: %d",
1821 				device->devid, ret);
1822 			goto out;
1823 		}
1824 	}
1825 
1826 	init_completion(&device->kobj_unregister);
1827 	ret = kobject_init_and_add(&device->devid_kobj, &devid_ktype,
1828 				   devinfo_kobj, "%llu", device->devid);
1829 	if (ret) {
1830 		kobject_put(&device->devid_kobj);
1831 		btrfs_warn(device->fs_info,
1832 			   "devinfo init for devid %llu failed: %d",
1833 			   device->devid, ret);
1834 	}
1835 
1836 out:
1837 	memalloc_nofs_restore(nofs_flag);
1838 	return ret;
1839 }
1840 
btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices * fs_devices)1841 static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
1842 {
1843 	int ret;
1844 	struct btrfs_device *device;
1845 	struct btrfs_fs_devices *seed;
1846 
1847 	list_for_each_entry(device, &fs_devices->devices, dev_list) {
1848 		ret = btrfs_sysfs_add_device(device);
1849 		if (ret)
1850 			goto fail;
1851 	}
1852 
1853 	list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1854 		list_for_each_entry(device, &seed->devices, dev_list) {
1855 			ret = btrfs_sysfs_add_device(device);
1856 			if (ret)
1857 				goto fail;
1858 		}
1859 	}
1860 
1861 	return 0;
1862 
1863 fail:
1864 	btrfs_sysfs_remove_fs_devices(fs_devices);
1865 	return ret;
1866 }
1867 
btrfs_kobject_uevent(struct block_device * bdev,enum kobject_action action)1868 void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
1869 {
1870 	int ret;
1871 
1872 	ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
1873 	if (ret)
1874 		pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
1875 			action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
1876 			&disk_to_dev(bdev->bd_disk)->kobj);
1877 }
1878 
btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices * fs_devices)1879 void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
1880 
1881 {
1882 	char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
1883 
1884 	/*
1885 	 * Sprouting changes fsid of the mounted filesystem, rename the fsid
1886 	 * directory
1887 	 */
1888 	snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fs_devices->fsid);
1889 	if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
1890 		btrfs_warn(fs_devices->fs_info,
1891 				"sysfs: failed to create fsid for sprout");
1892 }
1893 
btrfs_sysfs_update_devid(struct btrfs_device * device)1894 void btrfs_sysfs_update_devid(struct btrfs_device *device)
1895 {
1896 	char tmp[24];
1897 
1898 	snprintf(tmp, sizeof(tmp), "%llu", device->devid);
1899 
1900 	if (kobject_rename(&device->devid_kobj, tmp))
1901 		btrfs_warn(device->fs_devices->fs_info,
1902 			   "sysfs: failed to update devid for %llu",
1903 			   device->devid);
1904 }
1905 
1906 /* /sys/fs/btrfs/ entry */
1907 static struct kset *btrfs_kset;
1908 
1909 /*
1910  * Creates:
1911  *		/sys/fs/btrfs/UUID
1912  *
1913  * Can be called by the device discovery thread.
1914  */
btrfs_sysfs_add_fsid(struct btrfs_fs_devices * fs_devs)1915 int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
1916 {
1917 	int error;
1918 
1919 	init_completion(&fs_devs->kobj_unregister);
1920 	fs_devs->fsid_kobj.kset = btrfs_kset;
1921 	error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
1922 				     "%pU", fs_devs->fsid);
1923 	if (error) {
1924 		kobject_put(&fs_devs->fsid_kobj);
1925 		return error;
1926 	}
1927 
1928 	fs_devs->devices_kobj = kobject_create_and_add("devices",
1929 						       &fs_devs->fsid_kobj);
1930 	if (!fs_devs->devices_kobj) {
1931 		btrfs_err(fs_devs->fs_info,
1932 			  "failed to init sysfs device interface");
1933 		btrfs_sysfs_remove_fsid(fs_devs);
1934 		return -ENOMEM;
1935 	}
1936 
1937 	fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
1938 						       &fs_devs->fsid_kobj);
1939 	if (!fs_devs->devinfo_kobj) {
1940 		btrfs_err(fs_devs->fs_info,
1941 			  "failed to init sysfs devinfo kobject");
1942 		btrfs_sysfs_remove_fsid(fs_devs);
1943 		return -ENOMEM;
1944 	}
1945 
1946 	return 0;
1947 }
1948 
btrfs_sysfs_add_mounted(struct btrfs_fs_info * fs_info)1949 int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
1950 {
1951 	int error;
1952 	struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
1953 	struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
1954 
1955 	error = btrfs_sysfs_add_fs_devices(fs_devs);
1956 	if (error)
1957 		return error;
1958 
1959 	error = sysfs_create_files(fsid_kobj, btrfs_attrs);
1960 	if (error) {
1961 		btrfs_sysfs_remove_fs_devices(fs_devs);
1962 		return error;
1963 	}
1964 
1965 	error = sysfs_create_group(fsid_kobj,
1966 				   &btrfs_feature_attr_group);
1967 	if (error)
1968 		goto failure;
1969 
1970 #ifdef CONFIG_BTRFS_DEBUG
1971 	fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
1972 	if (!fs_info->debug_kobj) {
1973 		error = -ENOMEM;
1974 		goto failure;
1975 	}
1976 
1977 	error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1978 	if (error)
1979 		goto failure;
1980 #endif
1981 
1982 	/* Discard directory */
1983 	fs_info->discard_kobj = kobject_create_and_add("discard", fsid_kobj);
1984 	if (!fs_info->discard_kobj) {
1985 		error = -ENOMEM;
1986 		goto failure;
1987 	}
1988 
1989 	error = sysfs_create_files(fs_info->discard_kobj, discard_attrs);
1990 	if (error)
1991 		goto failure;
1992 
1993 	error = addrm_unknown_feature_attrs(fs_info, true);
1994 	if (error)
1995 		goto failure;
1996 
1997 	error = sysfs_create_link(fsid_kobj, &fs_info->sb->s_bdi->dev->kobj, "bdi");
1998 	if (error)
1999 		goto failure;
2000 
2001 	fs_info->space_info_kobj = kobject_create_and_add("allocation",
2002 						  fsid_kobj);
2003 	if (!fs_info->space_info_kobj) {
2004 		error = -ENOMEM;
2005 		goto failure;
2006 	}
2007 
2008 	error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
2009 	if (error)
2010 		goto failure;
2011 
2012 	return 0;
2013 failure:
2014 	btrfs_sysfs_remove_mounted(fs_info);
2015 	return error;
2016 }
2017 
qgroup_enabled_show(struct kobject * qgroups_kobj,struct kobj_attribute * a,char * buf)2018 static ssize_t qgroup_enabled_show(struct kobject *qgroups_kobj,
2019 				   struct kobj_attribute *a,
2020 				   char *buf)
2021 {
2022 	struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2023 	bool enabled;
2024 
2025 	spin_lock(&fs_info->qgroup_lock);
2026 	enabled = fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON;
2027 	spin_unlock(&fs_info->qgroup_lock);
2028 
2029 	return sysfs_emit(buf, "%d\n", enabled);
2030 }
2031 BTRFS_ATTR(qgroups, enabled, qgroup_enabled_show);
2032 
qgroup_inconsistent_show(struct kobject * qgroups_kobj,struct kobj_attribute * a,char * buf)2033 static ssize_t qgroup_inconsistent_show(struct kobject *qgroups_kobj,
2034 					struct kobj_attribute *a,
2035 					char *buf)
2036 {
2037 	struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2038 	bool inconsistent;
2039 
2040 	spin_lock(&fs_info->qgroup_lock);
2041 	inconsistent = (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT);
2042 	spin_unlock(&fs_info->qgroup_lock);
2043 
2044 	return sysfs_emit(buf, "%d\n", inconsistent);
2045 }
2046 BTRFS_ATTR(qgroups, inconsistent, qgroup_inconsistent_show);
2047 
qgroup_drop_subtree_thres_show(struct kobject * qgroups_kobj,struct kobj_attribute * a,char * buf)2048 static ssize_t qgroup_drop_subtree_thres_show(struct kobject *qgroups_kobj,
2049 					      struct kobj_attribute *a,
2050 					      char *buf)
2051 {
2052 	struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2053 	u8 result;
2054 
2055 	spin_lock(&fs_info->qgroup_lock);
2056 	result = fs_info->qgroup_drop_subtree_thres;
2057 	spin_unlock(&fs_info->qgroup_lock);
2058 
2059 	return sysfs_emit(buf, "%d\n", result);
2060 }
2061 
qgroup_drop_subtree_thres_store(struct kobject * qgroups_kobj,struct kobj_attribute * a,const char * buf,size_t len)2062 static ssize_t qgroup_drop_subtree_thres_store(struct kobject *qgroups_kobj,
2063 					       struct kobj_attribute *a,
2064 					       const char *buf, size_t len)
2065 {
2066 	struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2067 	u8 new_thres;
2068 	int ret;
2069 
2070 	ret = kstrtou8(buf, 10, &new_thres);
2071 	if (ret)
2072 		return -EINVAL;
2073 
2074 	if (new_thres > BTRFS_MAX_LEVEL)
2075 		return -EINVAL;
2076 
2077 	spin_lock(&fs_info->qgroup_lock);
2078 	fs_info->qgroup_drop_subtree_thres = new_thres;
2079 	spin_unlock(&fs_info->qgroup_lock);
2080 
2081 	return len;
2082 }
2083 BTRFS_ATTR_RW(qgroups, drop_subtree_threshold, qgroup_drop_subtree_thres_show,
2084 	      qgroup_drop_subtree_thres_store);
2085 
2086 /*
2087  * Qgroups global info
2088  *
2089  * Path: /sys/fs/btrfs/<uuid>/qgroups/
2090  */
2091 static struct attribute *qgroups_attrs[] = {
2092 	BTRFS_ATTR_PTR(qgroups, enabled),
2093 	BTRFS_ATTR_PTR(qgroups, inconsistent),
2094 	BTRFS_ATTR_PTR(qgroups, drop_subtree_threshold),
2095 	NULL
2096 };
2097 ATTRIBUTE_GROUPS(qgroups);
2098 
qgroups_release(struct kobject * kobj)2099 static void qgroups_release(struct kobject *kobj)
2100 {
2101 	kfree(kobj);
2102 }
2103 
2104 static struct kobj_type qgroups_ktype = {
2105 	.sysfs_ops = &kobj_sysfs_ops,
2106 	.default_groups = qgroups_groups,
2107 	.release = qgroups_release,
2108 };
2109 
qgroup_kobj_to_fs_info(struct kobject * kobj)2110 static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
2111 {
2112 	return to_fs_info(kobj->parent->parent);
2113 }
2114 
2115 #define QGROUP_ATTR(_member, _show_name)					\
2116 static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj,		\
2117 					   struct kobj_attribute *a,		\
2118 					   char *buf)				\
2119 {										\
2120 	struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);	\
2121 	struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,			\
2122 			struct btrfs_qgroup, kobj);				\
2123 	return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf);	\
2124 }										\
2125 BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
2126 
2127 #define QGROUP_RSV_ATTR(_name, _type)						\
2128 static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj,	\
2129 					     struct kobj_attribute *a,		\
2130 					     char *buf)				\
2131 {										\
2132 	struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);	\
2133 	struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,			\
2134 			struct btrfs_qgroup, kobj);				\
2135 	return btrfs_show_u64(&qgroup->rsv.values[_type],			\
2136 			&fs_info->qgroup_lock, buf);				\
2137 }										\
2138 BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
2139 
2140 QGROUP_ATTR(rfer, referenced);
2141 QGROUP_ATTR(excl, exclusive);
2142 QGROUP_ATTR(max_rfer, max_referenced);
2143 QGROUP_ATTR(max_excl, max_exclusive);
2144 QGROUP_ATTR(lim_flags, limit_flags);
2145 QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
2146 QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
2147 QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
2148 
2149 /*
2150  * Qgroup information.
2151  *
2152  * Path: /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>/
2153  */
2154 static struct attribute *qgroup_attrs[] = {
2155 	BTRFS_ATTR_PTR(qgroup, referenced),
2156 	BTRFS_ATTR_PTR(qgroup, exclusive),
2157 	BTRFS_ATTR_PTR(qgroup, max_referenced),
2158 	BTRFS_ATTR_PTR(qgroup, max_exclusive),
2159 	BTRFS_ATTR_PTR(qgroup, limit_flags),
2160 	BTRFS_ATTR_PTR(qgroup, rsv_data),
2161 	BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
2162 	BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
2163 	NULL
2164 };
2165 ATTRIBUTE_GROUPS(qgroup);
2166 
qgroup_release(struct kobject * kobj)2167 static void qgroup_release(struct kobject *kobj)
2168 {
2169 	struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
2170 
2171 	memset(&qgroup->kobj, 0, sizeof(*kobj));
2172 }
2173 
2174 static struct kobj_type qgroup_ktype = {
2175 	.sysfs_ops = &kobj_sysfs_ops,
2176 	.release = qgroup_release,
2177 	.default_groups = qgroup_groups,
2178 };
2179 
btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info * fs_info,struct btrfs_qgroup * qgroup)2180 int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
2181 				struct btrfs_qgroup *qgroup)
2182 {
2183 	struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
2184 	int ret;
2185 
2186 	if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2187 		return 0;
2188 	if (qgroup->kobj.state_initialized)
2189 		return 0;
2190 	if (!qgroups_kobj)
2191 		return -EINVAL;
2192 
2193 	ret = kobject_init_and_add(&qgroup->kobj, &qgroup_ktype, qgroups_kobj,
2194 			"%hu_%llu", btrfs_qgroup_level(qgroup->qgroupid),
2195 			btrfs_qgroup_subvolid(qgroup->qgroupid));
2196 	if (ret < 0)
2197 		kobject_put(&qgroup->kobj);
2198 
2199 	return ret;
2200 }
2201 
btrfs_sysfs_del_qgroups(struct btrfs_fs_info * fs_info)2202 void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
2203 {
2204 	struct btrfs_qgroup *qgroup;
2205 	struct btrfs_qgroup *next;
2206 
2207 	if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2208 		return;
2209 
2210 	rbtree_postorder_for_each_entry_safe(qgroup, next,
2211 					     &fs_info->qgroup_tree, node)
2212 		btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
2213 	if (fs_info->qgroups_kobj) {
2214 		kobject_del(fs_info->qgroups_kobj);
2215 		kobject_put(fs_info->qgroups_kobj);
2216 		fs_info->qgroups_kobj = NULL;
2217 	}
2218 }
2219 
2220 /* Called when qgroups get initialized, thus there is no need for locking */
btrfs_sysfs_add_qgroups(struct btrfs_fs_info * fs_info)2221 int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
2222 {
2223 	struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
2224 	struct btrfs_qgroup *qgroup;
2225 	struct btrfs_qgroup *next;
2226 	int ret = 0;
2227 
2228 	if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2229 		return 0;
2230 
2231 	ASSERT(fsid_kobj);
2232 	if (fs_info->qgroups_kobj)
2233 		return 0;
2234 
2235 	fs_info->qgroups_kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
2236 	if (!fs_info->qgroups_kobj)
2237 		return -ENOMEM;
2238 
2239 	ret = kobject_init_and_add(fs_info->qgroups_kobj, &qgroups_ktype,
2240 				   fsid_kobj, "qgroups");
2241 	if (ret < 0)
2242 		goto out;
2243 
2244 	rbtree_postorder_for_each_entry_safe(qgroup, next,
2245 					     &fs_info->qgroup_tree, node) {
2246 		ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
2247 		if (ret < 0)
2248 			goto out;
2249 	}
2250 
2251 out:
2252 	if (ret < 0)
2253 		btrfs_sysfs_del_qgroups(fs_info);
2254 	return ret;
2255 }
2256 
btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info * fs_info,struct btrfs_qgroup * qgroup)2257 void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
2258 				struct btrfs_qgroup *qgroup)
2259 {
2260 	if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2261 		return;
2262 
2263 	if (qgroup->kobj.state_initialized) {
2264 		kobject_del(&qgroup->kobj);
2265 		kobject_put(&qgroup->kobj);
2266 	}
2267 }
2268 
2269 /*
2270  * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
2271  * values in superblock. Call after any changes to incompat/compat_ro flags
2272  */
btrfs_sysfs_feature_update(struct btrfs_fs_info * fs_info,u64 bit,enum btrfs_feature_set set)2273 void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
2274 		u64 bit, enum btrfs_feature_set set)
2275 {
2276 	struct btrfs_fs_devices *fs_devs;
2277 	struct kobject *fsid_kobj;
2278 	u64 __maybe_unused features;
2279 	int __maybe_unused ret;
2280 
2281 	if (!fs_info)
2282 		return;
2283 
2284 	/*
2285 	 * See 14e46e04958df74 and e410e34fad913dd, feature bit updates are not
2286 	 * safe when called from some contexts (eg. balance)
2287 	 */
2288 	features = get_features(fs_info, set);
2289 	ASSERT(bit & supported_feature_masks[set]);
2290 
2291 	fs_devs = fs_info->fs_devices;
2292 	fsid_kobj = &fs_devs->fsid_kobj;
2293 
2294 	if (!fsid_kobj->state_initialized)
2295 		return;
2296 
2297 	/*
2298 	 * FIXME: this is too heavy to update just one value, ideally we'd like
2299 	 * to use sysfs_update_group but some refactoring is needed first.
2300 	 */
2301 	sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
2302 	ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
2303 }
2304 
btrfs_init_sysfs(void)2305 int __init btrfs_init_sysfs(void)
2306 {
2307 	int ret;
2308 
2309 	btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
2310 	if (!btrfs_kset)
2311 		return -ENOMEM;
2312 
2313 	init_feature_attrs();
2314 	ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2315 	if (ret)
2316 		goto out2;
2317 	ret = sysfs_merge_group(&btrfs_kset->kobj,
2318 				&btrfs_static_feature_attr_group);
2319 	if (ret)
2320 		goto out_remove_group;
2321 
2322 #ifdef CONFIG_BTRFS_DEBUG
2323 	ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2324 	if (ret) {
2325 		sysfs_unmerge_group(&btrfs_kset->kobj,
2326 				    &btrfs_static_feature_attr_group);
2327 		goto out_remove_group;
2328 	}
2329 #endif
2330 
2331 	return 0;
2332 
2333 out_remove_group:
2334 	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2335 out2:
2336 	kset_unregister(btrfs_kset);
2337 
2338 	return ret;
2339 }
2340 
btrfs_exit_sysfs(void)2341 void __cold btrfs_exit_sysfs(void)
2342 {
2343 	sysfs_unmerge_group(&btrfs_kset->kobj,
2344 			    &btrfs_static_feature_attr_group);
2345 	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2346 #ifdef CONFIG_BTRFS_DEBUG
2347 	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2348 #endif
2349 	kset_unregister(btrfs_kset);
2350 }
2351