xref: /openbmc/linux/fs/btrfs/sysfs.c (revision ed4543328f7108e1047b83b96ca7f7208747d930)
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 <linux/list.h>
13  #include <crypto/hash.h>
14  #include "messages.h"
15  #include "ctree.h"
16  #include "discard.h"
17  #include "disk-io.h"
18  #include "send.h"
19  #include "transaction.h"
20  #include "sysfs.h"
21  #include "volumes.h"
22  #include "space-info.h"
23  #include "block-group.h"
24  #include "qgroup.h"
25  #include "misc.h"
26  #include "fs.h"
27  #include "accessors.h"
28  
29  /*
30   * Structure name                       Path
31   * --------------------------------------------------------------------------
32   * btrfs_supported_static_feature_attrs /sys/fs/btrfs/features
33   * btrfs_supported_feature_attrs	/sys/fs/btrfs/features and
34   *					/sys/fs/btrfs/<uuid>/features
35   * btrfs_attrs				/sys/fs/btrfs/<uuid>
36   * devid_attrs				/sys/fs/btrfs/<uuid>/devinfo/<devid>
37   * allocation_attrs			/sys/fs/btrfs/<uuid>/allocation
38   * qgroup_attrs				/sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>
39   * space_info_attrs			/sys/fs/btrfs/<uuid>/allocation/<bg-type>
40   * raid_attrs				/sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>
41   * discard_attrs			/sys/fs/btrfs/<uuid>/discard
42   *
43   * When built with BTRFS_CONFIG_DEBUG:
44   *
45   * btrfs_debug_feature_attrs		/sys/fs/btrfs/debug
46   * btrfs_debug_mount_attrs		/sys/fs/btrfs/<uuid>/debug
47   */
48  
49  struct btrfs_feature_attr {
50  	struct kobj_attribute kobj_attr;
51  	enum btrfs_feature_set feature_set;
52  	u64 feature_bit;
53  };
54  
55  /* For raid type sysfs entries */
56  struct raid_kobject {
57  	u64 flags;
58  	struct kobject kobj;
59  };
60  
61  #define __INIT_KOBJ_ATTR(_name, _mode, _show, _store)			\
62  {									\
63  	.attr	= { .name = __stringify(_name), .mode = _mode },	\
64  	.show	= _show,						\
65  	.store	= _store,						\
66  }
67  
68  #define BTRFS_ATTR_W(_prefix, _name, _store)			        \
69  	static struct kobj_attribute btrfs_attr_##_prefix##_##_name =	\
70  			__INIT_KOBJ_ATTR(_name, 0200, NULL, _store)
71  
72  #define BTRFS_ATTR_RW(_prefix, _name, _show, _store)			\
73  	static struct kobj_attribute btrfs_attr_##_prefix##_##_name =	\
74  			__INIT_KOBJ_ATTR(_name, 0644, _show, _store)
75  
76  #define BTRFS_ATTR(_prefix, _name, _show)				\
77  	static struct kobj_attribute btrfs_attr_##_prefix##_##_name =	\
78  			__INIT_KOBJ_ATTR(_name, 0444, _show, NULL)
79  
80  #define BTRFS_ATTR_PTR(_prefix, _name)					\
81  	(&btrfs_attr_##_prefix##_##_name.attr)
82  
83  #define BTRFS_FEAT_ATTR(_name, _feature_set, _feature_prefix, _feature_bit)  \
84  static struct btrfs_feature_attr btrfs_attr_features_##_name = {	     \
85  	.kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO,			     \
86  				      btrfs_feature_attr_show,		     \
87  				      btrfs_feature_attr_store),	     \
88  	.feature_set	= _feature_set,					     \
89  	.feature_bit	= _feature_prefix ##_## _feature_bit,		     \
90  }
91  #define BTRFS_FEAT_ATTR_PTR(_name)					     \
92  	(&btrfs_attr_features_##_name.kobj_attr.attr)
93  
94  #define BTRFS_FEAT_ATTR_COMPAT(name, feature) \
95  	BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature)
96  #define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \
97  	BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
98  #define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
99  	BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
100  
101  static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
102  static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
103  static struct kobject *get_btrfs_kobj(struct kobject *kobj);
104  
to_btrfs_feature_attr(struct kobj_attribute * a)105  static struct btrfs_feature_attr *to_btrfs_feature_attr(struct kobj_attribute *a)
106  {
107  	return container_of(a, struct btrfs_feature_attr, kobj_attr);
108  }
109  
attr_to_btrfs_attr(struct attribute * attr)110  static struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr)
111  {
112  	return container_of(attr, struct kobj_attribute, attr);
113  }
114  
attr_to_btrfs_feature_attr(struct attribute * attr)115  static struct btrfs_feature_attr *attr_to_btrfs_feature_attr(
116  		struct attribute *attr)
117  {
118  	return to_btrfs_feature_attr(attr_to_btrfs_attr(attr));
119  }
120  
get_features(struct btrfs_fs_info * fs_info,enum btrfs_feature_set set)121  static u64 get_features(struct btrfs_fs_info *fs_info,
122  			enum btrfs_feature_set set)
123  {
124  	struct btrfs_super_block *disk_super = fs_info->super_copy;
125  	if (set == FEAT_COMPAT)
126  		return btrfs_super_compat_flags(disk_super);
127  	else if (set == FEAT_COMPAT_RO)
128  		return btrfs_super_compat_ro_flags(disk_super);
129  	else
130  		return btrfs_super_incompat_flags(disk_super);
131  }
132  
set_features(struct btrfs_fs_info * fs_info,enum btrfs_feature_set set,u64 features)133  static void set_features(struct btrfs_fs_info *fs_info,
134  			 enum btrfs_feature_set set, u64 features)
135  {
136  	struct btrfs_super_block *disk_super = fs_info->super_copy;
137  	if (set == FEAT_COMPAT)
138  		btrfs_set_super_compat_flags(disk_super, features);
139  	else if (set == FEAT_COMPAT_RO)
140  		btrfs_set_super_compat_ro_flags(disk_super, features);
141  	else
142  		btrfs_set_super_incompat_flags(disk_super, features);
143  }
144  
can_modify_feature(struct btrfs_feature_attr * fa)145  static int can_modify_feature(struct btrfs_feature_attr *fa)
146  {
147  	int val = 0;
148  	u64 set, clear;
149  	switch (fa->feature_set) {
150  	case FEAT_COMPAT:
151  		set = BTRFS_FEATURE_COMPAT_SAFE_SET;
152  		clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
153  		break;
154  	case FEAT_COMPAT_RO:
155  		set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
156  		clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
157  		break;
158  	case FEAT_INCOMPAT:
159  		set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
160  		clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
161  		break;
162  	default:
163  		pr_warn("btrfs: sysfs: unknown feature set %d\n",
164  				fa->feature_set);
165  		return 0;
166  	}
167  
168  	if (set & fa->feature_bit)
169  		val |= 1;
170  	if (clear & fa->feature_bit)
171  		val |= 2;
172  
173  	return val;
174  }
175  
btrfs_feature_attr_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)176  static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
177  				       struct kobj_attribute *a, char *buf)
178  {
179  	int val = 0;
180  	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
181  	struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
182  	if (fs_info) {
183  		u64 features = get_features(fs_info, fa->feature_set);
184  		if (features & fa->feature_bit)
185  			val = 1;
186  	} else
187  		val = can_modify_feature(fa);
188  
189  	return sysfs_emit(buf, "%d\n", val);
190  }
191  
btrfs_feature_attr_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t count)192  static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
193  					struct kobj_attribute *a,
194  					const char *buf, size_t count)
195  {
196  	struct btrfs_fs_info *fs_info;
197  	struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
198  	u64 features, set, clear;
199  	unsigned long val;
200  	int ret;
201  
202  	fs_info = to_fs_info(kobj);
203  	if (!fs_info)
204  		return -EPERM;
205  
206  	if (sb_rdonly(fs_info->sb))
207  		return -EROFS;
208  
209  	ret = kstrtoul(skip_spaces(buf), 0, &val);
210  	if (ret)
211  		return ret;
212  
213  	if (fa->feature_set == FEAT_COMPAT) {
214  		set = BTRFS_FEATURE_COMPAT_SAFE_SET;
215  		clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
216  	} else if (fa->feature_set == FEAT_COMPAT_RO) {
217  		set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
218  		clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
219  	} else {
220  		set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
221  		clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
222  	}
223  
224  	features = get_features(fs_info, fa->feature_set);
225  
226  	/* Nothing to do */
227  	if ((val && (features & fa->feature_bit)) ||
228  	    (!val && !(features & fa->feature_bit)))
229  		return count;
230  
231  	if ((val && !(set & fa->feature_bit)) ||
232  	    (!val && !(clear & fa->feature_bit))) {
233  		btrfs_info(fs_info,
234  			"%sabling feature %s on mounted fs is not supported.",
235  			val ? "En" : "Dis", fa->kobj_attr.attr.name);
236  		return -EPERM;
237  	}
238  
239  	btrfs_info(fs_info, "%s %s feature flag",
240  		   val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
241  
242  	spin_lock(&fs_info->super_lock);
243  	features = get_features(fs_info, fa->feature_set);
244  	if (val)
245  		features |= fa->feature_bit;
246  	else
247  		features &= ~fa->feature_bit;
248  	set_features(fs_info, fa->feature_set, features);
249  	spin_unlock(&fs_info->super_lock);
250  
251  	/*
252  	 * We don't want to do full transaction commit from inside sysfs
253  	 */
254  	set_bit(BTRFS_FS_NEED_TRANS_COMMIT, &fs_info->flags);
255  	wake_up_process(fs_info->transaction_kthread);
256  
257  	return count;
258  }
259  
btrfs_feature_visible(struct kobject * kobj,struct attribute * attr,int unused)260  static umode_t btrfs_feature_visible(struct kobject *kobj,
261  				     struct attribute *attr, int unused)
262  {
263  	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
264  	umode_t mode = attr->mode;
265  
266  	if (fs_info) {
267  		struct btrfs_feature_attr *fa;
268  		u64 features;
269  
270  		fa = attr_to_btrfs_feature_attr(attr);
271  		features = get_features(fs_info, fa->feature_set);
272  
273  		if (can_modify_feature(fa))
274  			mode |= S_IWUSR;
275  		else if (!(features & fa->feature_bit))
276  			mode = 0;
277  	}
278  
279  	return mode;
280  }
281  
282  BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
283  BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
284  BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
285  BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD);
286  BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
287  BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
288  BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
289  BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
290  BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
291  BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
292  BTRFS_FEAT_ATTR_COMPAT_RO(block_group_tree, BLOCK_GROUP_TREE);
293  BTRFS_FEAT_ATTR_INCOMPAT(raid1c34, RAID1C34);
294  #ifdef CONFIG_BLK_DEV_ZONED
295  BTRFS_FEAT_ATTR_INCOMPAT(zoned, ZONED);
296  #endif
297  #ifdef CONFIG_BTRFS_DEBUG
298  /* Remove once support for extent tree v2 is feature complete */
299  BTRFS_FEAT_ATTR_INCOMPAT(extent_tree_v2, EXTENT_TREE_V2);
300  #endif
301  #ifdef CONFIG_FS_VERITY
302  BTRFS_FEAT_ATTR_COMPAT_RO(verity, VERITY);
303  #endif
304  
305  /*
306   * Features which depend on feature bits and may differ between each fs.
307   *
308   * /sys/fs/btrfs/features      - all available features implemented by this version
309   * /sys/fs/btrfs/UUID/features - features of the fs which are enabled or
310   *                               can be changed on a mounted filesystem.
311   */
312  static struct attribute *btrfs_supported_feature_attrs[] = {
313  	BTRFS_FEAT_ATTR_PTR(default_subvol),
314  	BTRFS_FEAT_ATTR_PTR(mixed_groups),
315  	BTRFS_FEAT_ATTR_PTR(compress_lzo),
316  	BTRFS_FEAT_ATTR_PTR(compress_zstd),
317  	BTRFS_FEAT_ATTR_PTR(extended_iref),
318  	BTRFS_FEAT_ATTR_PTR(raid56),
319  	BTRFS_FEAT_ATTR_PTR(skinny_metadata),
320  	BTRFS_FEAT_ATTR_PTR(no_holes),
321  	BTRFS_FEAT_ATTR_PTR(metadata_uuid),
322  	BTRFS_FEAT_ATTR_PTR(free_space_tree),
323  	BTRFS_FEAT_ATTR_PTR(raid1c34),
324  	BTRFS_FEAT_ATTR_PTR(block_group_tree),
325  #ifdef CONFIG_BLK_DEV_ZONED
326  	BTRFS_FEAT_ATTR_PTR(zoned),
327  #endif
328  #ifdef CONFIG_BTRFS_DEBUG
329  	BTRFS_FEAT_ATTR_PTR(extent_tree_v2),
330  #endif
331  #ifdef CONFIG_FS_VERITY
332  	BTRFS_FEAT_ATTR_PTR(verity),
333  #endif
334  	NULL
335  };
336  
337  static const struct attribute_group btrfs_feature_attr_group = {
338  	.name = "features",
339  	.is_visible = btrfs_feature_visible,
340  	.attrs = btrfs_supported_feature_attrs,
341  };
342  
rmdir_subvol_show(struct kobject * kobj,struct kobj_attribute * ka,char * buf)343  static ssize_t rmdir_subvol_show(struct kobject *kobj,
344  				 struct kobj_attribute *ka, char *buf)
345  {
346  	return sysfs_emit(buf, "0\n");
347  }
348  BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
349  
supported_checksums_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)350  static ssize_t supported_checksums_show(struct kobject *kobj,
351  					struct kobj_attribute *a, char *buf)
352  {
353  	ssize_t ret = 0;
354  	int i;
355  
356  	for (i = 0; i < btrfs_get_num_csums(); i++) {
357  		/*
358  		 * This "trick" only works as long as 'enum btrfs_csum_type' has
359  		 * no holes in it
360  		 */
361  		ret += sysfs_emit_at(buf, ret, "%s%s", (i == 0 ? "" : " "),
362  				     btrfs_super_csum_name(i));
363  
364  	}
365  
366  	ret += sysfs_emit_at(buf, ret, "\n");
367  	return ret;
368  }
369  BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
370  
send_stream_version_show(struct kobject * kobj,struct kobj_attribute * ka,char * buf)371  static ssize_t send_stream_version_show(struct kobject *kobj,
372  					struct kobj_attribute *ka, char *buf)
373  {
374  	return sysfs_emit(buf, "%d\n", BTRFS_SEND_STREAM_VERSION);
375  }
376  BTRFS_ATTR(static_feature, send_stream_version, send_stream_version_show);
377  
378  static const char *rescue_opts[] = {
379  	"usebackuproot",
380  	"nologreplay",
381  	"ignorebadroots",
382  	"ignoredatacsums",
383  	"all",
384  };
385  
supported_rescue_options_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)386  static ssize_t supported_rescue_options_show(struct kobject *kobj,
387  					     struct kobj_attribute *a,
388  					     char *buf)
389  {
390  	ssize_t ret = 0;
391  	int i;
392  
393  	for (i = 0; i < ARRAY_SIZE(rescue_opts); i++)
394  		ret += sysfs_emit_at(buf, ret, "%s%s", (i ? " " : ""), rescue_opts[i]);
395  	ret += sysfs_emit_at(buf, ret, "\n");
396  	return ret;
397  }
398  BTRFS_ATTR(static_feature, supported_rescue_options,
399  	   supported_rescue_options_show);
400  
supported_sectorsizes_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)401  static ssize_t supported_sectorsizes_show(struct kobject *kobj,
402  					  struct kobj_attribute *a,
403  					  char *buf)
404  {
405  	ssize_t ret = 0;
406  
407  	/* An artificial limit to only support 4K and PAGE_SIZE */
408  	if (PAGE_SIZE > SZ_4K)
409  		ret += sysfs_emit_at(buf, ret, "%u ", SZ_4K);
410  	ret += sysfs_emit_at(buf, ret, "%lu\n", PAGE_SIZE);
411  
412  	return ret;
413  }
414  BTRFS_ATTR(static_feature, supported_sectorsizes,
415  	   supported_sectorsizes_show);
416  
acl_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)417  static ssize_t acl_show(struct kobject *kobj, struct kobj_attribute *a, char *buf)
418  {
419  	return sysfs_emit(buf, "%d\n", !!IS_ENABLED(CONFIG_BTRFS_FS_POSIX_ACL));
420  }
421  BTRFS_ATTR(static_feature, acl, acl_show);
422  
423  /*
424   * Features which only depend on kernel version.
425   *
426   * These are listed in /sys/fs/btrfs/features along with
427   * btrfs_supported_feature_attrs.
428   */
429  static struct attribute *btrfs_supported_static_feature_attrs[] = {
430  	BTRFS_ATTR_PTR(static_feature, acl),
431  	BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
432  	BTRFS_ATTR_PTR(static_feature, supported_checksums),
433  	BTRFS_ATTR_PTR(static_feature, send_stream_version),
434  	BTRFS_ATTR_PTR(static_feature, supported_rescue_options),
435  	BTRFS_ATTR_PTR(static_feature, supported_sectorsizes),
436  	NULL
437  };
438  
439  static const struct attribute_group btrfs_static_feature_attr_group = {
440  	.name = "features",
441  	.attrs = btrfs_supported_static_feature_attrs,
442  };
443  
444  /*
445   * Discard statistics and tunables
446   */
447  #define discard_to_fs_info(_kobj)	to_fs_info(get_btrfs_kobj(_kobj))
448  
btrfs_discardable_bytes_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)449  static ssize_t btrfs_discardable_bytes_show(struct kobject *kobj,
450  					    struct kobj_attribute *a,
451  					    char *buf)
452  {
453  	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
454  
455  	return sysfs_emit(buf, "%lld\n",
456  			atomic64_read(&fs_info->discard_ctl.discardable_bytes));
457  }
458  BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show);
459  
btrfs_discardable_extents_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)460  static ssize_t btrfs_discardable_extents_show(struct kobject *kobj,
461  					      struct kobj_attribute *a,
462  					      char *buf)
463  {
464  	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
465  
466  	return sysfs_emit(buf, "%d\n",
467  			atomic_read(&fs_info->discard_ctl.discardable_extents));
468  }
469  BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show);
470  
btrfs_discard_bitmap_bytes_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)471  static ssize_t btrfs_discard_bitmap_bytes_show(struct kobject *kobj,
472  					       struct kobj_attribute *a,
473  					       char *buf)
474  {
475  	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
476  
477  	return sysfs_emit(buf, "%llu\n",
478  			  fs_info->discard_ctl.discard_bitmap_bytes);
479  }
480  BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show);
481  
btrfs_discard_bytes_saved_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)482  static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj,
483  					      struct kobj_attribute *a,
484  					      char *buf)
485  {
486  	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
487  
488  	return sysfs_emit(buf, "%lld\n",
489  		atomic64_read(&fs_info->discard_ctl.discard_bytes_saved));
490  }
491  BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show);
492  
btrfs_discard_extent_bytes_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)493  static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj,
494  					       struct kobj_attribute *a,
495  					       char *buf)
496  {
497  	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
498  
499  	return sysfs_emit(buf, "%llu\n",
500  			  fs_info->discard_ctl.discard_extent_bytes);
501  }
502  BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show);
503  
btrfs_discard_iops_limit_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)504  static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj,
505  					     struct kobj_attribute *a,
506  					     char *buf)
507  {
508  	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
509  
510  	return sysfs_emit(buf, "%u\n",
511  			  READ_ONCE(fs_info->discard_ctl.iops_limit));
512  }
513  
btrfs_discard_iops_limit_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)514  static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj,
515  					      struct kobj_attribute *a,
516  					      const char *buf, size_t len)
517  {
518  	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
519  	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
520  	u32 iops_limit;
521  	int ret;
522  
523  	ret = kstrtou32(buf, 10, &iops_limit);
524  	if (ret)
525  		return -EINVAL;
526  
527  	WRITE_ONCE(discard_ctl->iops_limit, iops_limit);
528  	btrfs_discard_calc_delay(discard_ctl);
529  	btrfs_discard_schedule_work(discard_ctl, true);
530  	return len;
531  }
532  BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show,
533  	      btrfs_discard_iops_limit_store);
534  
btrfs_discard_kbps_limit_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)535  static ssize_t btrfs_discard_kbps_limit_show(struct kobject *kobj,
536  					     struct kobj_attribute *a,
537  					     char *buf)
538  {
539  	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
540  
541  	return sysfs_emit(buf, "%u\n",
542  			  READ_ONCE(fs_info->discard_ctl.kbps_limit));
543  }
544  
btrfs_discard_kbps_limit_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)545  static ssize_t btrfs_discard_kbps_limit_store(struct kobject *kobj,
546  					      struct kobj_attribute *a,
547  					      const char *buf, size_t len)
548  {
549  	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
550  	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
551  	u32 kbps_limit;
552  	int ret;
553  
554  	ret = kstrtou32(buf, 10, &kbps_limit);
555  	if (ret)
556  		return -EINVAL;
557  
558  	WRITE_ONCE(discard_ctl->kbps_limit, kbps_limit);
559  	btrfs_discard_schedule_work(discard_ctl, true);
560  	return len;
561  }
562  BTRFS_ATTR_RW(discard, kbps_limit, btrfs_discard_kbps_limit_show,
563  	      btrfs_discard_kbps_limit_store);
564  
btrfs_discard_max_discard_size_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)565  static ssize_t btrfs_discard_max_discard_size_show(struct kobject *kobj,
566  						   struct kobj_attribute *a,
567  						   char *buf)
568  {
569  	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
570  
571  	return sysfs_emit(buf, "%llu\n",
572  			  READ_ONCE(fs_info->discard_ctl.max_discard_size));
573  }
574  
btrfs_discard_max_discard_size_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)575  static ssize_t btrfs_discard_max_discard_size_store(struct kobject *kobj,
576  						    struct kobj_attribute *a,
577  						    const char *buf, size_t len)
578  {
579  	struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj);
580  	struct btrfs_discard_ctl *discard_ctl = &fs_info->discard_ctl;
581  	u64 max_discard_size;
582  	int ret;
583  
584  	ret = kstrtou64(buf, 10, &max_discard_size);
585  	if (ret)
586  		return -EINVAL;
587  
588  	WRITE_ONCE(discard_ctl->max_discard_size, max_discard_size);
589  
590  	return len;
591  }
592  BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show,
593  	      btrfs_discard_max_discard_size_store);
594  
595  /*
596   * Per-filesystem stats for discard (when mounted with discard=async).
597   *
598   * Path: /sys/fs/btrfs/<uuid>/discard/
599   */
600  static const struct attribute *discard_attrs[] = {
601  	BTRFS_ATTR_PTR(discard, discardable_bytes),
602  	BTRFS_ATTR_PTR(discard, discardable_extents),
603  	BTRFS_ATTR_PTR(discard, discard_bitmap_bytes),
604  	BTRFS_ATTR_PTR(discard, discard_bytes_saved),
605  	BTRFS_ATTR_PTR(discard, discard_extent_bytes),
606  	BTRFS_ATTR_PTR(discard, iops_limit),
607  	BTRFS_ATTR_PTR(discard, kbps_limit),
608  	BTRFS_ATTR_PTR(discard, max_discard_size),
609  	NULL,
610  };
611  
612  #ifdef CONFIG_BTRFS_DEBUG
613  
614  /*
615   * Per-filesystem runtime debugging exported via sysfs.
616   *
617   * Path: /sys/fs/btrfs/UUID/debug/
618   */
619  static const struct attribute *btrfs_debug_mount_attrs[] = {
620  	NULL,
621  };
622  
623  /*
624   * Runtime debugging exported via sysfs, applies to all mounted filesystems.
625   *
626   * Path: /sys/fs/btrfs/debug
627   */
628  static struct attribute *btrfs_debug_feature_attrs[] = {
629  	NULL
630  };
631  
632  static const struct attribute_group btrfs_debug_feature_attr_group = {
633  	.name = "debug",
634  	.attrs = btrfs_debug_feature_attrs,
635  };
636  
637  #endif
638  
btrfs_show_u64(u64 * value_ptr,spinlock_t * lock,char * buf)639  static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
640  {
641  	u64 val;
642  	if (lock)
643  		spin_lock(lock);
644  	val = *value_ptr;
645  	if (lock)
646  		spin_unlock(lock);
647  	return sysfs_emit(buf, "%llu\n", val);
648  }
649  
global_rsv_size_show(struct kobject * kobj,struct kobj_attribute * ka,char * buf)650  static ssize_t global_rsv_size_show(struct kobject *kobj,
651  				    struct kobj_attribute *ka, char *buf)
652  {
653  	struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
654  	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
655  	return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
656  }
657  BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
658  
global_rsv_reserved_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)659  static ssize_t global_rsv_reserved_show(struct kobject *kobj,
660  					struct kobj_attribute *a, char *buf)
661  {
662  	struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
663  	struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
664  	return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
665  }
666  BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
667  
668  #define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
669  #define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
670  
671  static ssize_t raid_bytes_show(struct kobject *kobj,
672  			       struct kobj_attribute *attr, char *buf);
673  BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
674  BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
675  
raid_bytes_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)676  static ssize_t raid_bytes_show(struct kobject *kobj,
677  			       struct kobj_attribute *attr, char *buf)
678  
679  {
680  	struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
681  	struct btrfs_block_group *block_group;
682  	int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
683  	u64 val = 0;
684  
685  	down_read(&sinfo->groups_sem);
686  	list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
687  		if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
688  			val += block_group->length;
689  		else
690  			val += block_group->used;
691  	}
692  	up_read(&sinfo->groups_sem);
693  	return sysfs_emit(buf, "%llu\n", val);
694  }
695  
696  /*
697   * Allocation information about block group profiles.
698   *
699   * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/<bg-profile>/
700   */
701  static struct attribute *raid_attrs[] = {
702  	BTRFS_ATTR_PTR(raid, total_bytes),
703  	BTRFS_ATTR_PTR(raid, used_bytes),
704  	NULL
705  };
706  ATTRIBUTE_GROUPS(raid);
707  
release_raid_kobj(struct kobject * kobj)708  static void release_raid_kobj(struct kobject *kobj)
709  {
710  	kfree(to_raid_kobj(kobj));
711  }
712  
713  static const struct kobj_type btrfs_raid_ktype = {
714  	.sysfs_ops = &kobj_sysfs_ops,
715  	.release = release_raid_kobj,
716  	.default_groups = raid_groups,
717  };
718  
719  #define SPACE_INFO_ATTR(field)						\
720  static ssize_t btrfs_space_info_show_##field(struct kobject *kobj,	\
721  					     struct kobj_attribute *a,	\
722  					     char *buf)			\
723  {									\
724  	struct btrfs_space_info *sinfo = to_space_info(kobj);		\
725  	return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf);	\
726  }									\
727  BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
728  
btrfs_chunk_size_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)729  static ssize_t btrfs_chunk_size_show(struct kobject *kobj,
730  				     struct kobj_attribute *a, char *buf)
731  {
732  	struct btrfs_space_info *sinfo = to_space_info(kobj);
733  
734  	return sysfs_emit(buf, "%llu\n", READ_ONCE(sinfo->chunk_size));
735  }
736  
737  /*
738   * Store new chunk size in space info. Can be called on a read-only filesystem.
739   *
740   * If the new chunk size value is larger than 10% of free space it is reduced
741   * to match that limit. Alignment must be to 256M and the system chunk size
742   * cannot be set.
743   */
btrfs_chunk_size_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)744  static ssize_t btrfs_chunk_size_store(struct kobject *kobj,
745  				      struct kobj_attribute *a,
746  				      const char *buf, size_t len)
747  {
748  	struct btrfs_space_info *space_info = to_space_info(kobj);
749  	struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
750  	char *retptr;
751  	u64 val;
752  
753  	if (!capable(CAP_SYS_ADMIN))
754  		return -EPERM;
755  
756  	if (!fs_info->fs_devices)
757  		return -EINVAL;
758  
759  	if (btrfs_is_zoned(fs_info))
760  		return -EINVAL;
761  
762  	/* System block type must not be changed. */
763  	if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM)
764  		return -EPERM;
765  
766  	val = memparse(buf, &retptr);
767  	/* There could be trailing '\n', also catch any typos after the value */
768  	retptr = skip_spaces(retptr);
769  	if (*retptr != 0 || val == 0)
770  		return -EINVAL;
771  
772  	val = min(val, BTRFS_MAX_DATA_CHUNK_SIZE);
773  
774  	/* Limit stripe size to 10% of available space. */
775  	val = min(mult_perc(fs_info->fs_devices->total_rw_bytes, 10), val);
776  
777  	/* Must be multiple of 256M. */
778  	val &= ~((u64)SZ_256M - 1);
779  
780  	/* Must be at least 256M. */
781  	if (val < SZ_256M)
782  		return -EINVAL;
783  
784  	btrfs_update_space_info_chunk_size(space_info, val);
785  
786  	return len;
787  }
788  
btrfs_size_classes_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)789  static ssize_t btrfs_size_classes_show(struct kobject *kobj,
790  				       struct kobj_attribute *a, char *buf)
791  {
792  	struct btrfs_space_info *sinfo = to_space_info(kobj);
793  	struct btrfs_block_group *bg;
794  	u32 none = 0;
795  	u32 small = 0;
796  	u32 medium = 0;
797  	u32 large = 0;
798  
799  	for (int i = 0; i < BTRFS_NR_RAID_TYPES; ++i) {
800  		down_read(&sinfo->groups_sem);
801  		list_for_each_entry(bg, &sinfo->block_groups[i], list) {
802  			if (!btrfs_block_group_should_use_size_class(bg))
803  				continue;
804  			switch (bg->size_class) {
805  			case BTRFS_BG_SZ_NONE:
806  				none++;
807  				break;
808  			case BTRFS_BG_SZ_SMALL:
809  				small++;
810  				break;
811  			case BTRFS_BG_SZ_MEDIUM:
812  				medium++;
813  				break;
814  			case BTRFS_BG_SZ_LARGE:
815  				large++;
816  				break;
817  			}
818  		}
819  		up_read(&sinfo->groups_sem);
820  	}
821  	return sysfs_emit(buf, "none %u\n"
822  			       "small %u\n"
823  			       "medium %u\n"
824  			       "large %u\n",
825  			       none, small, medium, large);
826  }
827  
828  #ifdef CONFIG_BTRFS_DEBUG
829  /*
830   * Request chunk allocation with current chunk size.
831   */
btrfs_force_chunk_alloc_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)832  static ssize_t btrfs_force_chunk_alloc_store(struct kobject *kobj,
833  					     struct kobj_attribute *a,
834  					     const char *buf, size_t len)
835  {
836  	struct btrfs_space_info *space_info = to_space_info(kobj);
837  	struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
838  	struct btrfs_trans_handle *trans;
839  	bool val;
840  	int ret;
841  
842  	if (!capable(CAP_SYS_ADMIN))
843  		return -EPERM;
844  
845  	if (sb_rdonly(fs_info->sb))
846  		return -EROFS;
847  
848  	ret = kstrtobool(buf, &val);
849  	if (ret)
850  		return ret;
851  
852  	if (!val)
853  		return -EINVAL;
854  
855  	/*
856  	 * This is unsafe to be called from sysfs context and may cause
857  	 * unexpected problems.
858  	 */
859  	trans = btrfs_start_transaction(fs_info->tree_root, 0);
860  	if (IS_ERR(trans))
861  		return PTR_ERR(trans);
862  	ret = btrfs_force_chunk_alloc(trans, space_info->flags);
863  	btrfs_end_transaction(trans);
864  
865  	if (ret == 1)
866  		return len;
867  
868  	return -ENOSPC;
869  }
870  BTRFS_ATTR_W(space_info, force_chunk_alloc, btrfs_force_chunk_alloc_store);
871  
872  #endif
873  
874  SPACE_INFO_ATTR(flags);
875  SPACE_INFO_ATTR(total_bytes);
876  SPACE_INFO_ATTR(bytes_used);
877  SPACE_INFO_ATTR(bytes_pinned);
878  SPACE_INFO_ATTR(bytes_reserved);
879  SPACE_INFO_ATTR(bytes_may_use);
880  SPACE_INFO_ATTR(bytes_readonly);
881  SPACE_INFO_ATTR(bytes_zone_unusable);
882  SPACE_INFO_ATTR(disk_used);
883  SPACE_INFO_ATTR(disk_total);
884  BTRFS_ATTR_RW(space_info, chunk_size, btrfs_chunk_size_show, btrfs_chunk_size_store);
885  BTRFS_ATTR(space_info, size_classes, btrfs_size_classes_show);
886  
btrfs_sinfo_bg_reclaim_threshold_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)887  static ssize_t btrfs_sinfo_bg_reclaim_threshold_show(struct kobject *kobj,
888  						     struct kobj_attribute *a,
889  						     char *buf)
890  {
891  	struct btrfs_space_info *space_info = to_space_info(kobj);
892  
893  	return sysfs_emit(buf, "%d\n", READ_ONCE(space_info->bg_reclaim_threshold));
894  }
895  
btrfs_sinfo_bg_reclaim_threshold_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)896  static ssize_t btrfs_sinfo_bg_reclaim_threshold_store(struct kobject *kobj,
897  						      struct kobj_attribute *a,
898  						      const char *buf, size_t len)
899  {
900  	struct btrfs_space_info *space_info = to_space_info(kobj);
901  	int thresh;
902  	int ret;
903  
904  	ret = kstrtoint(buf, 10, &thresh);
905  	if (ret)
906  		return ret;
907  
908  	if (thresh < 0 || thresh > 100)
909  		return -EINVAL;
910  
911  	WRITE_ONCE(space_info->bg_reclaim_threshold, thresh);
912  
913  	return len;
914  }
915  
916  BTRFS_ATTR_RW(space_info, bg_reclaim_threshold,
917  	      btrfs_sinfo_bg_reclaim_threshold_show,
918  	      btrfs_sinfo_bg_reclaim_threshold_store);
919  
920  /*
921   * Allocation information about block group types.
922   *
923   * Path: /sys/fs/btrfs/<uuid>/allocation/<bg-type>/
924   */
925  static struct attribute *space_info_attrs[] = {
926  	BTRFS_ATTR_PTR(space_info, flags),
927  	BTRFS_ATTR_PTR(space_info, total_bytes),
928  	BTRFS_ATTR_PTR(space_info, bytes_used),
929  	BTRFS_ATTR_PTR(space_info, bytes_pinned),
930  	BTRFS_ATTR_PTR(space_info, bytes_reserved),
931  	BTRFS_ATTR_PTR(space_info, bytes_may_use),
932  	BTRFS_ATTR_PTR(space_info, bytes_readonly),
933  	BTRFS_ATTR_PTR(space_info, bytes_zone_unusable),
934  	BTRFS_ATTR_PTR(space_info, disk_used),
935  	BTRFS_ATTR_PTR(space_info, disk_total),
936  	BTRFS_ATTR_PTR(space_info, bg_reclaim_threshold),
937  	BTRFS_ATTR_PTR(space_info, chunk_size),
938  	BTRFS_ATTR_PTR(space_info, size_classes),
939  #ifdef CONFIG_BTRFS_DEBUG
940  	BTRFS_ATTR_PTR(space_info, force_chunk_alloc),
941  #endif
942  	NULL,
943  };
944  ATTRIBUTE_GROUPS(space_info);
945  
space_info_release(struct kobject * kobj)946  static void space_info_release(struct kobject *kobj)
947  {
948  	struct btrfs_space_info *sinfo = to_space_info(kobj);
949  	kfree(sinfo);
950  }
951  
952  static const struct kobj_type space_info_ktype = {
953  	.sysfs_ops = &kobj_sysfs_ops,
954  	.release = space_info_release,
955  	.default_groups = space_info_groups,
956  };
957  
958  /*
959   * Allocation information about block groups.
960   *
961   * Path: /sys/fs/btrfs/<uuid>/allocation/
962   */
963  static const struct attribute *allocation_attrs[] = {
964  	BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
965  	BTRFS_ATTR_PTR(allocation, global_rsv_size),
966  	NULL,
967  };
968  
btrfs_label_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)969  static ssize_t btrfs_label_show(struct kobject *kobj,
970  				struct kobj_attribute *a, char *buf)
971  {
972  	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
973  	char *label = fs_info->super_copy->label;
974  	ssize_t ret;
975  
976  	spin_lock(&fs_info->super_lock);
977  	ret = sysfs_emit(buf, label[0] ? "%s\n" : "%s", label);
978  	spin_unlock(&fs_info->super_lock);
979  
980  	return ret;
981  }
982  
btrfs_label_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)983  static ssize_t btrfs_label_store(struct kobject *kobj,
984  				 struct kobj_attribute *a,
985  				 const char *buf, size_t len)
986  {
987  	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
988  	size_t p_len;
989  
990  	if (!fs_info)
991  		return -EPERM;
992  
993  	if (sb_rdonly(fs_info->sb))
994  		return -EROFS;
995  
996  	/*
997  	 * p_len is the len until the first occurrence of either
998  	 * '\n' or '\0'
999  	 */
1000  	p_len = strcspn(buf, "\n");
1001  
1002  	if (p_len >= BTRFS_LABEL_SIZE)
1003  		return -EINVAL;
1004  
1005  	spin_lock(&fs_info->super_lock);
1006  	memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
1007  	memcpy(fs_info->super_copy->label, buf, p_len);
1008  	spin_unlock(&fs_info->super_lock);
1009  
1010  	/*
1011  	 * We don't want to do full transaction commit from inside sysfs
1012  	 */
1013  	set_bit(BTRFS_FS_NEED_TRANS_COMMIT, &fs_info->flags);
1014  	wake_up_process(fs_info->transaction_kthread);
1015  
1016  	return len;
1017  }
1018  BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
1019  
btrfs_nodesize_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1020  static ssize_t btrfs_nodesize_show(struct kobject *kobj,
1021  				struct kobj_attribute *a, char *buf)
1022  {
1023  	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1024  
1025  	return sysfs_emit(buf, "%u\n", fs_info->nodesize);
1026  }
1027  
1028  BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
1029  
btrfs_sectorsize_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1030  static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
1031  				struct kobj_attribute *a, char *buf)
1032  {
1033  	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1034  
1035  	return sysfs_emit(buf, "%u\n", fs_info->sectorsize);
1036  }
1037  
1038  BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
1039  
btrfs_commit_stats_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1040  static ssize_t btrfs_commit_stats_show(struct kobject *kobj,
1041  				       struct kobj_attribute *a, char *buf)
1042  {
1043  	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1044  
1045  	return sysfs_emit(buf,
1046  		"commits %llu\n"
1047  		"last_commit_ms %llu\n"
1048  		"max_commit_ms %llu\n"
1049  		"total_commit_ms %llu\n",
1050  		fs_info->commit_stats.commit_count,
1051  		div_u64(fs_info->commit_stats.last_commit_dur, NSEC_PER_MSEC),
1052  		div_u64(fs_info->commit_stats.max_commit_dur, NSEC_PER_MSEC),
1053  		div_u64(fs_info->commit_stats.total_commit_dur, NSEC_PER_MSEC));
1054  }
1055  
btrfs_commit_stats_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)1056  static ssize_t btrfs_commit_stats_store(struct kobject *kobj,
1057  					struct kobj_attribute *a,
1058  					const char *buf, size_t len)
1059  {
1060  	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1061  	unsigned long val;
1062  	int ret;
1063  
1064  	if (!fs_info)
1065  		return -EPERM;
1066  
1067  	if (!capable(CAP_SYS_RESOURCE))
1068  		return -EPERM;
1069  
1070  	ret = kstrtoul(buf, 10, &val);
1071  	if (ret)
1072  		return ret;
1073  	if (val)
1074  		return -EINVAL;
1075  
1076  	WRITE_ONCE(fs_info->commit_stats.max_commit_dur, 0);
1077  
1078  	return len;
1079  }
1080  BTRFS_ATTR_RW(, commit_stats, btrfs_commit_stats_show, btrfs_commit_stats_store);
1081  
btrfs_clone_alignment_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1082  static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
1083  				struct kobj_attribute *a, char *buf)
1084  {
1085  	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1086  
1087  	return sysfs_emit(buf, "%u\n", fs_info->sectorsize);
1088  }
1089  
1090  BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
1091  
quota_override_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1092  static ssize_t quota_override_show(struct kobject *kobj,
1093  				   struct kobj_attribute *a, char *buf)
1094  {
1095  	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1096  	int quota_override;
1097  
1098  	quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1099  	return sysfs_emit(buf, "%d\n", quota_override);
1100  }
1101  
quota_override_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)1102  static ssize_t quota_override_store(struct kobject *kobj,
1103  				    struct kobj_attribute *a,
1104  				    const char *buf, size_t len)
1105  {
1106  	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1107  	unsigned long knob;
1108  	int err;
1109  
1110  	if (!fs_info)
1111  		return -EPERM;
1112  
1113  	if (!capable(CAP_SYS_RESOURCE))
1114  		return -EPERM;
1115  
1116  	err = kstrtoul(buf, 10, &knob);
1117  	if (err)
1118  		return err;
1119  	if (knob > 1)
1120  		return -EINVAL;
1121  
1122  	if (knob)
1123  		set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1124  	else
1125  		clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
1126  
1127  	return len;
1128  }
1129  
1130  BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
1131  
btrfs_metadata_uuid_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1132  static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
1133  				struct kobj_attribute *a, char *buf)
1134  {
1135  	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1136  
1137  	return sysfs_emit(buf, "%pU\n", fs_info->fs_devices->metadata_uuid);
1138  }
1139  
1140  BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
1141  
btrfs_checksum_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1142  static ssize_t btrfs_checksum_show(struct kobject *kobj,
1143  				   struct kobj_attribute *a, char *buf)
1144  {
1145  	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1146  	u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
1147  
1148  	return sysfs_emit(buf, "%s (%s)\n",
1149  			  btrfs_super_csum_name(csum_type),
1150  			  crypto_shash_driver_name(fs_info->csum_shash));
1151  }
1152  
1153  BTRFS_ATTR(, checksum, btrfs_checksum_show);
1154  
btrfs_exclusive_operation_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1155  static ssize_t btrfs_exclusive_operation_show(struct kobject *kobj,
1156  		struct kobj_attribute *a, char *buf)
1157  {
1158  	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1159  	const char *str;
1160  
1161  	switch (READ_ONCE(fs_info->exclusive_operation)) {
1162  		case  BTRFS_EXCLOP_NONE:
1163  			str = "none\n";
1164  			break;
1165  		case BTRFS_EXCLOP_BALANCE:
1166  			str = "balance\n";
1167  			break;
1168  		case BTRFS_EXCLOP_BALANCE_PAUSED:
1169  			str = "balance paused\n";
1170  			break;
1171  		case BTRFS_EXCLOP_DEV_ADD:
1172  			str = "device add\n";
1173  			break;
1174  		case BTRFS_EXCLOP_DEV_REMOVE:
1175  			str = "device remove\n";
1176  			break;
1177  		case BTRFS_EXCLOP_DEV_REPLACE:
1178  			str = "device replace\n";
1179  			break;
1180  		case BTRFS_EXCLOP_RESIZE:
1181  			str = "resize\n";
1182  			break;
1183  		case BTRFS_EXCLOP_SWAP_ACTIVATE:
1184  			str = "swap activate\n";
1185  			break;
1186  		default:
1187  			str = "UNKNOWN\n";
1188  			break;
1189  	}
1190  	return sysfs_emit(buf, "%s", str);
1191  }
1192  BTRFS_ATTR(, exclusive_operation, btrfs_exclusive_operation_show);
1193  
btrfs_generation_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1194  static ssize_t btrfs_generation_show(struct kobject *kobj,
1195  				     struct kobj_attribute *a, char *buf)
1196  {
1197  	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1198  
1199  	return sysfs_emit(buf, "%llu\n", fs_info->generation);
1200  }
1201  BTRFS_ATTR(, generation, btrfs_generation_show);
1202  
1203  static const char * const btrfs_read_policy_name[] = { "pid" };
1204  
btrfs_read_policy_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1205  static ssize_t btrfs_read_policy_show(struct kobject *kobj,
1206  				      struct kobj_attribute *a, char *buf)
1207  {
1208  	struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1209  	ssize_t ret = 0;
1210  	int i;
1211  
1212  	for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1213  		if (fs_devices->read_policy == i)
1214  			ret += sysfs_emit_at(buf, ret, "%s[%s]",
1215  					 (ret == 0 ? "" : " "),
1216  					 btrfs_read_policy_name[i]);
1217  		else
1218  			ret += sysfs_emit_at(buf, ret, "%s%s",
1219  					 (ret == 0 ? "" : " "),
1220  					 btrfs_read_policy_name[i]);
1221  	}
1222  
1223  	ret += sysfs_emit_at(buf, ret, "\n");
1224  
1225  	return ret;
1226  }
1227  
btrfs_read_policy_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)1228  static ssize_t btrfs_read_policy_store(struct kobject *kobj,
1229  				       struct kobj_attribute *a,
1230  				       const char *buf, size_t len)
1231  {
1232  	struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
1233  	int i;
1234  
1235  	for (i = 0; i < BTRFS_NR_READ_POLICY; i++) {
1236  		if (sysfs_streq(buf, btrfs_read_policy_name[i])) {
1237  			if (i != fs_devices->read_policy) {
1238  				fs_devices->read_policy = i;
1239  				btrfs_info(fs_devices->fs_info,
1240  					   "read policy set to '%s'",
1241  					   btrfs_read_policy_name[i]);
1242  			}
1243  			return len;
1244  		}
1245  	}
1246  
1247  	return -EINVAL;
1248  }
1249  BTRFS_ATTR_RW(, read_policy, btrfs_read_policy_show, btrfs_read_policy_store);
1250  
btrfs_bg_reclaim_threshold_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1251  static ssize_t btrfs_bg_reclaim_threshold_show(struct kobject *kobj,
1252  					       struct kobj_attribute *a,
1253  					       char *buf)
1254  {
1255  	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1256  
1257  	return sysfs_emit(buf, "%d\n", READ_ONCE(fs_info->bg_reclaim_threshold));
1258  }
1259  
btrfs_bg_reclaim_threshold_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)1260  static ssize_t btrfs_bg_reclaim_threshold_store(struct kobject *kobj,
1261  						struct kobj_attribute *a,
1262  						const char *buf, size_t len)
1263  {
1264  	struct btrfs_fs_info *fs_info = to_fs_info(kobj);
1265  	int thresh;
1266  	int ret;
1267  
1268  	ret = kstrtoint(buf, 10, &thresh);
1269  	if (ret)
1270  		return ret;
1271  
1272  #ifdef CONFIG_BTRFS_DEBUG
1273  	if (thresh != 0 && (thresh > 100))
1274  		return -EINVAL;
1275  #else
1276  	if (thresh != 0 && (thresh <= 50 || thresh > 100))
1277  		return -EINVAL;
1278  #endif
1279  
1280  	WRITE_ONCE(fs_info->bg_reclaim_threshold, thresh);
1281  
1282  	return len;
1283  }
1284  BTRFS_ATTR_RW(, bg_reclaim_threshold, btrfs_bg_reclaim_threshold_show,
1285  	      btrfs_bg_reclaim_threshold_store);
1286  
1287  /*
1288   * Per-filesystem information and stats.
1289   *
1290   * Path: /sys/fs/btrfs/<uuid>/
1291   */
1292  static const struct attribute *btrfs_attrs[] = {
1293  	BTRFS_ATTR_PTR(, label),
1294  	BTRFS_ATTR_PTR(, nodesize),
1295  	BTRFS_ATTR_PTR(, sectorsize),
1296  	BTRFS_ATTR_PTR(, clone_alignment),
1297  	BTRFS_ATTR_PTR(, quota_override),
1298  	BTRFS_ATTR_PTR(, metadata_uuid),
1299  	BTRFS_ATTR_PTR(, checksum),
1300  	BTRFS_ATTR_PTR(, exclusive_operation),
1301  	BTRFS_ATTR_PTR(, generation),
1302  	BTRFS_ATTR_PTR(, read_policy),
1303  	BTRFS_ATTR_PTR(, bg_reclaim_threshold),
1304  	BTRFS_ATTR_PTR(, commit_stats),
1305  	NULL,
1306  };
1307  
btrfs_release_fsid_kobj(struct kobject * kobj)1308  static void btrfs_release_fsid_kobj(struct kobject *kobj)
1309  {
1310  	struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
1311  
1312  	memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
1313  	complete(&fs_devs->kobj_unregister);
1314  }
1315  
1316  static const struct kobj_type btrfs_ktype = {
1317  	.sysfs_ops	= &kobj_sysfs_ops,
1318  	.release	= btrfs_release_fsid_kobj,
1319  };
1320  
to_fs_devs(struct kobject * kobj)1321  static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
1322  {
1323  	if (kobj->ktype != &btrfs_ktype)
1324  		return NULL;
1325  	return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
1326  }
1327  
to_fs_info(struct kobject * kobj)1328  static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
1329  {
1330  	if (kobj->ktype != &btrfs_ktype)
1331  		return NULL;
1332  	return to_fs_devs(kobj)->fs_info;
1333  }
1334  
get_btrfs_kobj(struct kobject * kobj)1335  static struct kobject *get_btrfs_kobj(struct kobject *kobj)
1336  {
1337  	while (kobj) {
1338  		if (kobj->ktype == &btrfs_ktype)
1339  			return kobj;
1340  		kobj = kobj->parent;
1341  	}
1342  	return NULL;
1343  }
1344  
1345  #define NUM_FEATURE_BITS 64
1346  #define BTRFS_FEATURE_NAME_MAX 13
1347  static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
1348  static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
1349  
1350  static_assert(ARRAY_SIZE(btrfs_unknown_feature_names) ==
1351  	      ARRAY_SIZE(btrfs_feature_attrs));
1352  static_assert(ARRAY_SIZE(btrfs_unknown_feature_names[0]) ==
1353  	      ARRAY_SIZE(btrfs_feature_attrs[0]));
1354  
1355  static const u64 supported_feature_masks[FEAT_MAX] = {
1356  	[FEAT_COMPAT]    = BTRFS_FEATURE_COMPAT_SUPP,
1357  	[FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
1358  	[FEAT_INCOMPAT]  = BTRFS_FEATURE_INCOMPAT_SUPP,
1359  };
1360  
addrm_unknown_feature_attrs(struct btrfs_fs_info * fs_info,bool add)1361  static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
1362  {
1363  	int set;
1364  
1365  	for (set = 0; set < FEAT_MAX; set++) {
1366  		int i;
1367  		struct attribute *attrs[2];
1368  		struct attribute_group agroup = {
1369  			.name = "features",
1370  			.attrs = attrs,
1371  		};
1372  		u64 features = get_features(fs_info, set);
1373  		features &= ~supported_feature_masks[set];
1374  
1375  		if (!features)
1376  			continue;
1377  
1378  		attrs[1] = NULL;
1379  		for (i = 0; i < NUM_FEATURE_BITS; i++) {
1380  			struct btrfs_feature_attr *fa;
1381  
1382  			if (!(features & (1ULL << i)))
1383  				continue;
1384  
1385  			fa = &btrfs_feature_attrs[set][i];
1386  			attrs[0] = &fa->kobj_attr.attr;
1387  			if (add) {
1388  				int ret;
1389  				ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
1390  							&agroup);
1391  				if (ret)
1392  					return ret;
1393  			} else
1394  				sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
1395  						    &agroup);
1396  		}
1397  
1398  	}
1399  	return 0;
1400  }
1401  
__btrfs_sysfs_remove_fsid(struct btrfs_fs_devices * fs_devs)1402  static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1403  {
1404  	if (fs_devs->devinfo_kobj) {
1405  		kobject_del(fs_devs->devinfo_kobj);
1406  		kobject_put(fs_devs->devinfo_kobj);
1407  		fs_devs->devinfo_kobj = NULL;
1408  	}
1409  
1410  	if (fs_devs->devices_kobj) {
1411  		kobject_del(fs_devs->devices_kobj);
1412  		kobject_put(fs_devs->devices_kobj);
1413  		fs_devs->devices_kobj = NULL;
1414  	}
1415  
1416  	if (fs_devs->fsid_kobj.state_initialized) {
1417  		kobject_del(&fs_devs->fsid_kobj);
1418  		kobject_put(&fs_devs->fsid_kobj);
1419  		wait_for_completion(&fs_devs->kobj_unregister);
1420  	}
1421  }
1422  
1423  /* when fs_devs is NULL it will remove all fsid kobject */
btrfs_sysfs_remove_fsid(struct btrfs_fs_devices * fs_devs)1424  void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
1425  {
1426  	struct list_head *fs_uuids = btrfs_get_fs_uuids();
1427  
1428  	if (fs_devs) {
1429  		__btrfs_sysfs_remove_fsid(fs_devs);
1430  		return;
1431  	}
1432  
1433  	list_for_each_entry(fs_devs, fs_uuids, fs_list) {
1434  		__btrfs_sysfs_remove_fsid(fs_devs);
1435  	}
1436  }
1437  
btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices * fs_devices)1438  static void btrfs_sysfs_remove_fs_devices(struct btrfs_fs_devices *fs_devices)
1439  {
1440  	struct btrfs_device *device;
1441  	struct btrfs_fs_devices *seed;
1442  
1443  	list_for_each_entry(device, &fs_devices->devices, dev_list)
1444  		btrfs_sysfs_remove_device(device);
1445  
1446  	list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1447  		list_for_each_entry(device, &seed->devices, dev_list)
1448  			btrfs_sysfs_remove_device(device);
1449  	}
1450  }
1451  
btrfs_sysfs_remove_mounted(struct btrfs_fs_info * fs_info)1452  void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
1453  {
1454  	struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
1455  
1456  	sysfs_remove_link(fsid_kobj, "bdi");
1457  
1458  	if (fs_info->space_info_kobj) {
1459  		sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
1460  		kobject_del(fs_info->space_info_kobj);
1461  		kobject_put(fs_info->space_info_kobj);
1462  	}
1463  	if (fs_info->discard_kobj) {
1464  		sysfs_remove_files(fs_info->discard_kobj, discard_attrs);
1465  		kobject_del(fs_info->discard_kobj);
1466  		kobject_put(fs_info->discard_kobj);
1467  	}
1468  #ifdef CONFIG_BTRFS_DEBUG
1469  	if (fs_info->debug_kobj) {
1470  		sysfs_remove_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
1471  		kobject_del(fs_info->debug_kobj);
1472  		kobject_put(fs_info->debug_kobj);
1473  	}
1474  #endif
1475  	addrm_unknown_feature_attrs(fs_info, false);
1476  	sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
1477  	sysfs_remove_files(fsid_kobj, btrfs_attrs);
1478  	btrfs_sysfs_remove_fs_devices(fs_info->fs_devices);
1479  }
1480  
1481  static const char * const btrfs_feature_set_names[FEAT_MAX] = {
1482  	[FEAT_COMPAT]	 = "compat",
1483  	[FEAT_COMPAT_RO] = "compat_ro",
1484  	[FEAT_INCOMPAT]	 = "incompat",
1485  };
1486  
btrfs_feature_set_name(enum btrfs_feature_set set)1487  const char *btrfs_feature_set_name(enum btrfs_feature_set set)
1488  {
1489  	return btrfs_feature_set_names[set];
1490  }
1491  
btrfs_printable_features(enum btrfs_feature_set set,u64 flags)1492  char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
1493  {
1494  	size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
1495  	int len = 0;
1496  	int i;
1497  	char *str;
1498  
1499  	str = kmalloc(bufsize, GFP_KERNEL);
1500  	if (!str)
1501  		return str;
1502  
1503  	for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1504  		const char *name;
1505  
1506  		if (!(flags & (1ULL << i)))
1507  			continue;
1508  
1509  		name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
1510  		len += scnprintf(str + len, bufsize - len, "%s%s",
1511  				len ? "," : "", name);
1512  	}
1513  
1514  	return str;
1515  }
1516  
init_feature_attrs(void)1517  static void init_feature_attrs(void)
1518  {
1519  	struct btrfs_feature_attr *fa;
1520  	int set, i;
1521  
1522  	memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
1523  	memset(btrfs_unknown_feature_names, 0,
1524  	       sizeof(btrfs_unknown_feature_names));
1525  
1526  	for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
1527  		struct btrfs_feature_attr *sfa;
1528  		struct attribute *a = btrfs_supported_feature_attrs[i];
1529  		int bit;
1530  		sfa = attr_to_btrfs_feature_attr(a);
1531  		bit = ilog2(sfa->feature_bit);
1532  		fa = &btrfs_feature_attrs[sfa->feature_set][bit];
1533  
1534  		fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
1535  	}
1536  
1537  	for (set = 0; set < FEAT_MAX; set++) {
1538  		for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
1539  			char *name = btrfs_unknown_feature_names[set][i];
1540  			fa = &btrfs_feature_attrs[set][i];
1541  
1542  			if (fa->kobj_attr.attr.name)
1543  				continue;
1544  
1545  			snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
1546  				 btrfs_feature_set_names[set], i);
1547  
1548  			fa->kobj_attr.attr.name = name;
1549  			fa->kobj_attr.attr.mode = S_IRUGO;
1550  			fa->feature_set = set;
1551  			fa->feature_bit = 1ULL << i;
1552  		}
1553  	}
1554  }
1555  
1556  /*
1557   * Create a sysfs entry for a given block group type at path
1558   * /sys/fs/btrfs/UUID/allocation/data/TYPE
1559   */
btrfs_sysfs_add_block_group_type(struct btrfs_block_group * cache)1560  void btrfs_sysfs_add_block_group_type(struct btrfs_block_group *cache)
1561  {
1562  	struct btrfs_fs_info *fs_info = cache->fs_info;
1563  	struct btrfs_space_info *space_info = cache->space_info;
1564  	struct raid_kobject *rkobj;
1565  	const int index = btrfs_bg_flags_to_raid_index(cache->flags);
1566  	unsigned int nofs_flag;
1567  	int ret;
1568  
1569  	/*
1570  	 * Setup a NOFS context because kobject_add(), deep in its call chain,
1571  	 * does GFP_KERNEL allocations, and we are often called in a context
1572  	 * where if reclaim is triggered we can deadlock (we are either holding
1573  	 * a transaction handle or some lock required for a transaction
1574  	 * commit).
1575  	 */
1576  	nofs_flag = memalloc_nofs_save();
1577  
1578  	rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
1579  	if (!rkobj) {
1580  		memalloc_nofs_restore(nofs_flag);
1581  		btrfs_warn(cache->fs_info,
1582  				"couldn't alloc memory for raid level kobject");
1583  		return;
1584  	}
1585  
1586  	rkobj->flags = cache->flags;
1587  	kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
1588  
1589  	/*
1590  	 * We call this either on mount, or if we've created a block group for a
1591  	 * new index type while running (i.e. when restriping).  The running
1592  	 * case is tricky because we could race with other threads, so we need
1593  	 * to have this check to make sure we didn't already init the kobject.
1594  	 *
1595  	 * We don't have to protect on the free side because it only happens on
1596  	 * unmount.
1597  	 */
1598  	spin_lock(&space_info->lock);
1599  	if (space_info->block_group_kobjs[index]) {
1600  		spin_unlock(&space_info->lock);
1601  		kobject_put(&rkobj->kobj);
1602  		return;
1603  	} else {
1604  		space_info->block_group_kobjs[index] = &rkobj->kobj;
1605  	}
1606  	spin_unlock(&space_info->lock);
1607  
1608  	ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
1609  			  btrfs_bg_type_to_raid_name(rkobj->flags));
1610  	memalloc_nofs_restore(nofs_flag);
1611  	if (ret) {
1612  		spin_lock(&space_info->lock);
1613  		space_info->block_group_kobjs[index] = NULL;
1614  		spin_unlock(&space_info->lock);
1615  		kobject_put(&rkobj->kobj);
1616  		btrfs_warn(fs_info,
1617  			"failed to add kobject for block cache, ignoring");
1618  		return;
1619  	}
1620  }
1621  
1622  /*
1623   * Remove sysfs directories for all block group types of a given space info and
1624   * the space info as well
1625   */
btrfs_sysfs_remove_space_info(struct btrfs_space_info * space_info)1626  void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
1627  {
1628  	int i;
1629  
1630  	for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
1631  		struct kobject *kobj;
1632  
1633  		kobj = space_info->block_group_kobjs[i];
1634  		space_info->block_group_kobjs[i] = NULL;
1635  		if (kobj) {
1636  			kobject_del(kobj);
1637  			kobject_put(kobj);
1638  		}
1639  	}
1640  	kobject_del(&space_info->kobj);
1641  	kobject_put(&space_info->kobj);
1642  }
1643  
alloc_name(u64 flags)1644  static const char *alloc_name(u64 flags)
1645  {
1646  	switch (flags) {
1647  	case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
1648  		return "mixed";
1649  	case BTRFS_BLOCK_GROUP_METADATA:
1650  		return "metadata";
1651  	case BTRFS_BLOCK_GROUP_DATA:
1652  		return "data";
1653  	case BTRFS_BLOCK_GROUP_SYSTEM:
1654  		return "system";
1655  	default:
1656  		WARN_ON(1);
1657  		return "invalid-combination";
1658  	}
1659  }
1660  
1661  /*
1662   * Create a sysfs entry for a space info type at path
1663   * /sys/fs/btrfs/UUID/allocation/TYPE
1664   */
btrfs_sysfs_add_space_info_type(struct btrfs_fs_info * fs_info,struct btrfs_space_info * space_info)1665  int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
1666  				    struct btrfs_space_info *space_info)
1667  {
1668  	int ret;
1669  
1670  	ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
1671  				   fs_info->space_info_kobj, "%s",
1672  				   alloc_name(space_info->flags));
1673  	if (ret) {
1674  		kobject_put(&space_info->kobj);
1675  		return ret;
1676  	}
1677  
1678  	return 0;
1679  }
1680  
btrfs_sysfs_remove_device(struct btrfs_device * device)1681  void btrfs_sysfs_remove_device(struct btrfs_device *device)
1682  {
1683  	struct kobject *devices_kobj;
1684  
1685  	/*
1686  	 * Seed fs_devices devices_kobj aren't used, fetch kobject from the
1687  	 * fs_info::fs_devices.
1688  	 */
1689  	devices_kobj = device->fs_info->fs_devices->devices_kobj;
1690  	ASSERT(devices_kobj);
1691  
1692  	if (device->bdev)
1693  		sysfs_remove_link(devices_kobj, bdev_kobj(device->bdev)->name);
1694  
1695  	if (device->devid_kobj.state_initialized) {
1696  		kobject_del(&device->devid_kobj);
1697  		kobject_put(&device->devid_kobj);
1698  		wait_for_completion(&device->kobj_unregister);
1699  	}
1700  }
1701  
btrfs_devinfo_in_fs_metadata_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1702  static ssize_t btrfs_devinfo_in_fs_metadata_show(struct kobject *kobj,
1703  					         struct kobj_attribute *a,
1704  					         char *buf)
1705  {
1706  	int val;
1707  	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1708  						   devid_kobj);
1709  
1710  	val = !!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
1711  
1712  	return sysfs_emit(buf, "%d\n", val);
1713  }
1714  BTRFS_ATTR(devid, in_fs_metadata, btrfs_devinfo_in_fs_metadata_show);
1715  
btrfs_devinfo_missing_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1716  static ssize_t btrfs_devinfo_missing_show(struct kobject *kobj,
1717  					struct kobj_attribute *a, char *buf)
1718  {
1719  	int val;
1720  	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1721  						   devid_kobj);
1722  
1723  	val = !!test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state);
1724  
1725  	return sysfs_emit(buf, "%d\n", val);
1726  }
1727  BTRFS_ATTR(devid, missing, btrfs_devinfo_missing_show);
1728  
btrfs_devinfo_replace_target_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1729  static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj,
1730  					         struct kobj_attribute *a,
1731  					         char *buf)
1732  {
1733  	int val;
1734  	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1735  						   devid_kobj);
1736  
1737  	val = !!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state);
1738  
1739  	return sysfs_emit(buf, "%d\n", val);
1740  }
1741  BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show);
1742  
btrfs_devinfo_scrub_speed_max_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1743  static ssize_t btrfs_devinfo_scrub_speed_max_show(struct kobject *kobj,
1744  					     struct kobj_attribute *a,
1745  					     char *buf)
1746  {
1747  	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1748  						   devid_kobj);
1749  
1750  	return sysfs_emit(buf, "%llu\n", READ_ONCE(device->scrub_speed_max));
1751  }
1752  
btrfs_devinfo_scrub_speed_max_store(struct kobject * kobj,struct kobj_attribute * a,const char * buf,size_t len)1753  static ssize_t btrfs_devinfo_scrub_speed_max_store(struct kobject *kobj,
1754  					      struct kobj_attribute *a,
1755  					      const char *buf, size_t len)
1756  {
1757  	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1758  						   devid_kobj);
1759  	char *endptr;
1760  	unsigned long long limit;
1761  
1762  	limit = memparse(buf, &endptr);
1763  	/* There could be trailing '\n', also catch any typos after the value. */
1764  	endptr = skip_spaces(endptr);
1765  	if (*endptr != 0)
1766  		return -EINVAL;
1767  	WRITE_ONCE(device->scrub_speed_max, limit);
1768  	return len;
1769  }
1770  BTRFS_ATTR_RW(devid, scrub_speed_max, btrfs_devinfo_scrub_speed_max_show,
1771  	      btrfs_devinfo_scrub_speed_max_store);
1772  
btrfs_devinfo_writeable_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1773  static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj,
1774  					    struct kobj_attribute *a, char *buf)
1775  {
1776  	int val;
1777  	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1778  						   devid_kobj);
1779  
1780  	val = !!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state);
1781  
1782  	return sysfs_emit(buf, "%d\n", val);
1783  }
1784  BTRFS_ATTR(devid, writeable, btrfs_devinfo_writeable_show);
1785  
btrfs_devinfo_fsid_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1786  static ssize_t btrfs_devinfo_fsid_show(struct kobject *kobj,
1787  				       struct kobj_attribute *a, char *buf)
1788  {
1789  	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1790  						   devid_kobj);
1791  
1792  	return sysfs_emit(buf, "%pU\n", device->fs_devices->fsid);
1793  }
1794  BTRFS_ATTR(devid, fsid, btrfs_devinfo_fsid_show);
1795  
btrfs_devinfo_error_stats_show(struct kobject * kobj,struct kobj_attribute * a,char * buf)1796  static ssize_t btrfs_devinfo_error_stats_show(struct kobject *kobj,
1797  		struct kobj_attribute *a, char *buf)
1798  {
1799  	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1800  						   devid_kobj);
1801  
1802  	if (!device->dev_stats_valid)
1803  		return sysfs_emit(buf, "invalid\n");
1804  
1805  	/*
1806  	 * Print all at once so we get a snapshot of all values from the same
1807  	 * time. Keep them in sync and in order of definition of
1808  	 * btrfs_dev_stat_values.
1809  	 */
1810  	return sysfs_emit(buf,
1811  		"write_errs %d\n"
1812  		"read_errs %d\n"
1813  		"flush_errs %d\n"
1814  		"corruption_errs %d\n"
1815  		"generation_errs %d\n",
1816  		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_WRITE_ERRS),
1817  		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_READ_ERRS),
1818  		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_FLUSH_ERRS),
1819  		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_CORRUPTION_ERRS),
1820  		btrfs_dev_stat_read(device, BTRFS_DEV_STAT_GENERATION_ERRS));
1821  }
1822  BTRFS_ATTR(devid, error_stats, btrfs_devinfo_error_stats_show);
1823  
1824  /*
1825   * Information about one device.
1826   *
1827   * Path: /sys/fs/btrfs/<uuid>/devinfo/<devid>/
1828   */
1829  static struct attribute *devid_attrs[] = {
1830  	BTRFS_ATTR_PTR(devid, error_stats),
1831  	BTRFS_ATTR_PTR(devid, fsid),
1832  	BTRFS_ATTR_PTR(devid, in_fs_metadata),
1833  	BTRFS_ATTR_PTR(devid, missing),
1834  	BTRFS_ATTR_PTR(devid, replace_target),
1835  	BTRFS_ATTR_PTR(devid, scrub_speed_max),
1836  	BTRFS_ATTR_PTR(devid, writeable),
1837  	NULL
1838  };
1839  ATTRIBUTE_GROUPS(devid);
1840  
btrfs_release_devid_kobj(struct kobject * kobj)1841  static void btrfs_release_devid_kobj(struct kobject *kobj)
1842  {
1843  	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
1844  						   devid_kobj);
1845  
1846  	memset(&device->devid_kobj, 0, sizeof(struct kobject));
1847  	complete(&device->kobj_unregister);
1848  }
1849  
1850  static const struct kobj_type devid_ktype = {
1851  	.sysfs_ops	= &kobj_sysfs_ops,
1852  	.default_groups = devid_groups,
1853  	.release	= btrfs_release_devid_kobj,
1854  };
1855  
btrfs_sysfs_add_device(struct btrfs_device * device)1856  int btrfs_sysfs_add_device(struct btrfs_device *device)
1857  {
1858  	int ret;
1859  	unsigned int nofs_flag;
1860  	struct kobject *devices_kobj;
1861  	struct kobject *devinfo_kobj;
1862  
1863  	/*
1864  	 * Make sure we use the fs_info::fs_devices to fetch the kobjects even
1865  	 * for the seed fs_devices
1866  	 */
1867  	devices_kobj = device->fs_info->fs_devices->devices_kobj;
1868  	devinfo_kobj = device->fs_info->fs_devices->devinfo_kobj;
1869  	ASSERT(devices_kobj);
1870  	ASSERT(devinfo_kobj);
1871  
1872  	nofs_flag = memalloc_nofs_save();
1873  
1874  	if (device->bdev) {
1875  		struct kobject *disk_kobj = bdev_kobj(device->bdev);
1876  
1877  		ret = sysfs_create_link(devices_kobj, disk_kobj, disk_kobj->name);
1878  		if (ret) {
1879  			btrfs_warn(device->fs_info,
1880  				"creating sysfs device link for devid %llu failed: %d",
1881  				device->devid, ret);
1882  			goto out;
1883  		}
1884  	}
1885  
1886  	init_completion(&device->kobj_unregister);
1887  	ret = kobject_init_and_add(&device->devid_kobj, &devid_ktype,
1888  				   devinfo_kobj, "%llu", device->devid);
1889  	if (ret) {
1890  		kobject_put(&device->devid_kobj);
1891  		btrfs_warn(device->fs_info,
1892  			   "devinfo init for devid %llu failed: %d",
1893  			   device->devid, ret);
1894  	}
1895  
1896  out:
1897  	memalloc_nofs_restore(nofs_flag);
1898  	return ret;
1899  }
1900  
btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices * fs_devices)1901  static int btrfs_sysfs_add_fs_devices(struct btrfs_fs_devices *fs_devices)
1902  {
1903  	int ret;
1904  	struct btrfs_device *device;
1905  	struct btrfs_fs_devices *seed;
1906  
1907  	list_for_each_entry(device, &fs_devices->devices, dev_list) {
1908  		ret = btrfs_sysfs_add_device(device);
1909  		if (ret)
1910  			goto fail;
1911  	}
1912  
1913  	list_for_each_entry(seed, &fs_devices->seed_list, seed_list) {
1914  		list_for_each_entry(device, &seed->devices, dev_list) {
1915  			ret = btrfs_sysfs_add_device(device);
1916  			if (ret)
1917  				goto fail;
1918  		}
1919  	}
1920  
1921  	return 0;
1922  
1923  fail:
1924  	btrfs_sysfs_remove_fs_devices(fs_devices);
1925  	return ret;
1926  }
1927  
btrfs_kobject_uevent(struct block_device * bdev,enum kobject_action action)1928  void btrfs_kobject_uevent(struct block_device *bdev, enum kobject_action action)
1929  {
1930  	int ret;
1931  
1932  	ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
1933  	if (ret)
1934  		pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
1935  			action, kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
1936  			&disk_to_dev(bdev->bd_disk)->kobj);
1937  }
1938  
btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices * fs_devices)1939  void btrfs_sysfs_update_sprout_fsid(struct btrfs_fs_devices *fs_devices)
1940  
1941  {
1942  	char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
1943  
1944  	/*
1945  	 * Sprouting changes fsid of the mounted filesystem, rename the fsid
1946  	 * directory
1947  	 */
1948  	snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU", fs_devices->fsid);
1949  	if (kobject_rename(&fs_devices->fsid_kobj, fsid_buf))
1950  		btrfs_warn(fs_devices->fs_info,
1951  				"sysfs: failed to create fsid for sprout");
1952  }
1953  
btrfs_sysfs_update_devid(struct btrfs_device * device)1954  void btrfs_sysfs_update_devid(struct btrfs_device *device)
1955  {
1956  	char tmp[24];
1957  
1958  	snprintf(tmp, sizeof(tmp), "%llu", device->devid);
1959  
1960  	if (kobject_rename(&device->devid_kobj, tmp))
1961  		btrfs_warn(device->fs_devices->fs_info,
1962  			   "sysfs: failed to update devid for %llu",
1963  			   device->devid);
1964  }
1965  
1966  /* /sys/fs/btrfs/ entry */
1967  static struct kset *btrfs_kset;
1968  
1969  /*
1970   * Creates:
1971   *		/sys/fs/btrfs/UUID
1972   *
1973   * Can be called by the device discovery thread.
1974   */
btrfs_sysfs_add_fsid(struct btrfs_fs_devices * fs_devs)1975  int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs)
1976  {
1977  	int error;
1978  
1979  	init_completion(&fs_devs->kobj_unregister);
1980  	fs_devs->fsid_kobj.kset = btrfs_kset;
1981  	error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, NULL,
1982  				     "%pU", fs_devs->fsid);
1983  	if (error) {
1984  		kobject_put(&fs_devs->fsid_kobj);
1985  		return error;
1986  	}
1987  
1988  	fs_devs->devices_kobj = kobject_create_and_add("devices",
1989  						       &fs_devs->fsid_kobj);
1990  	if (!fs_devs->devices_kobj) {
1991  		btrfs_err(fs_devs->fs_info,
1992  			  "failed to init sysfs device interface");
1993  		btrfs_sysfs_remove_fsid(fs_devs);
1994  		return -ENOMEM;
1995  	}
1996  
1997  	fs_devs->devinfo_kobj = kobject_create_and_add("devinfo",
1998  						       &fs_devs->fsid_kobj);
1999  	if (!fs_devs->devinfo_kobj) {
2000  		btrfs_err(fs_devs->fs_info,
2001  			  "failed to init sysfs devinfo kobject");
2002  		btrfs_sysfs_remove_fsid(fs_devs);
2003  		return -ENOMEM;
2004  	}
2005  
2006  	return 0;
2007  }
2008  
btrfs_sysfs_add_mounted(struct btrfs_fs_info * fs_info)2009  int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
2010  {
2011  	int error;
2012  	struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
2013  	struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
2014  
2015  	error = btrfs_sysfs_add_fs_devices(fs_devs);
2016  	if (error)
2017  		return error;
2018  
2019  	error = sysfs_create_files(fsid_kobj, btrfs_attrs);
2020  	if (error) {
2021  		btrfs_sysfs_remove_fs_devices(fs_devs);
2022  		return error;
2023  	}
2024  
2025  	error = sysfs_create_group(fsid_kobj,
2026  				   &btrfs_feature_attr_group);
2027  	if (error)
2028  		goto failure;
2029  
2030  #ifdef CONFIG_BTRFS_DEBUG
2031  	fs_info->debug_kobj = kobject_create_and_add("debug", fsid_kobj);
2032  	if (!fs_info->debug_kobj) {
2033  		error = -ENOMEM;
2034  		goto failure;
2035  	}
2036  
2037  	error = sysfs_create_files(fs_info->debug_kobj, btrfs_debug_mount_attrs);
2038  	if (error)
2039  		goto failure;
2040  #endif
2041  
2042  	/* Discard directory */
2043  	fs_info->discard_kobj = kobject_create_and_add("discard", fsid_kobj);
2044  	if (!fs_info->discard_kobj) {
2045  		error = -ENOMEM;
2046  		goto failure;
2047  	}
2048  
2049  	error = sysfs_create_files(fs_info->discard_kobj, discard_attrs);
2050  	if (error)
2051  		goto failure;
2052  
2053  	error = addrm_unknown_feature_attrs(fs_info, true);
2054  	if (error)
2055  		goto failure;
2056  
2057  	error = sysfs_create_link(fsid_kobj, &fs_info->sb->s_bdi->dev->kobj, "bdi");
2058  	if (error)
2059  		goto failure;
2060  
2061  	fs_info->space_info_kobj = kobject_create_and_add("allocation",
2062  						  fsid_kobj);
2063  	if (!fs_info->space_info_kobj) {
2064  		error = -ENOMEM;
2065  		goto failure;
2066  	}
2067  
2068  	error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
2069  	if (error)
2070  		goto failure;
2071  
2072  	return 0;
2073  failure:
2074  	btrfs_sysfs_remove_mounted(fs_info);
2075  	return error;
2076  }
2077  
qgroup_enabled_show(struct kobject * qgroups_kobj,struct kobj_attribute * a,char * buf)2078  static ssize_t qgroup_enabled_show(struct kobject *qgroups_kobj,
2079  				   struct kobj_attribute *a,
2080  				   char *buf)
2081  {
2082  	struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2083  	bool enabled;
2084  
2085  	spin_lock(&fs_info->qgroup_lock);
2086  	enabled = fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON;
2087  	spin_unlock(&fs_info->qgroup_lock);
2088  
2089  	return sysfs_emit(buf, "%d\n", enabled);
2090  }
2091  BTRFS_ATTR(qgroups, enabled, qgroup_enabled_show);
2092  
qgroup_inconsistent_show(struct kobject * qgroups_kobj,struct kobj_attribute * a,char * buf)2093  static ssize_t qgroup_inconsistent_show(struct kobject *qgroups_kobj,
2094  					struct kobj_attribute *a,
2095  					char *buf)
2096  {
2097  	struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2098  	bool inconsistent;
2099  
2100  	spin_lock(&fs_info->qgroup_lock);
2101  	inconsistent = (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT);
2102  	spin_unlock(&fs_info->qgroup_lock);
2103  
2104  	return sysfs_emit(buf, "%d\n", inconsistent);
2105  }
2106  BTRFS_ATTR(qgroups, inconsistent, qgroup_inconsistent_show);
2107  
qgroup_drop_subtree_thres_show(struct kobject * qgroups_kobj,struct kobj_attribute * a,char * buf)2108  static ssize_t qgroup_drop_subtree_thres_show(struct kobject *qgroups_kobj,
2109  					      struct kobj_attribute *a,
2110  					      char *buf)
2111  {
2112  	struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2113  	u8 result;
2114  
2115  	spin_lock(&fs_info->qgroup_lock);
2116  	result = fs_info->qgroup_drop_subtree_thres;
2117  	spin_unlock(&fs_info->qgroup_lock);
2118  
2119  	return sysfs_emit(buf, "%d\n", result);
2120  }
2121  
qgroup_drop_subtree_thres_store(struct kobject * qgroups_kobj,struct kobj_attribute * a,const char * buf,size_t len)2122  static ssize_t qgroup_drop_subtree_thres_store(struct kobject *qgroups_kobj,
2123  					       struct kobj_attribute *a,
2124  					       const char *buf, size_t len)
2125  {
2126  	struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent);
2127  	u8 new_thres;
2128  	int ret;
2129  
2130  	ret = kstrtou8(buf, 10, &new_thres);
2131  	if (ret)
2132  		return -EINVAL;
2133  
2134  	if (new_thres > BTRFS_MAX_LEVEL)
2135  		return -EINVAL;
2136  
2137  	spin_lock(&fs_info->qgroup_lock);
2138  	fs_info->qgroup_drop_subtree_thres = new_thres;
2139  	spin_unlock(&fs_info->qgroup_lock);
2140  
2141  	return len;
2142  }
2143  BTRFS_ATTR_RW(qgroups, drop_subtree_threshold, qgroup_drop_subtree_thres_show,
2144  	      qgroup_drop_subtree_thres_store);
2145  
2146  /*
2147   * Qgroups global info
2148   *
2149   * Path: /sys/fs/btrfs/<uuid>/qgroups/
2150   */
2151  static struct attribute *qgroups_attrs[] = {
2152  	BTRFS_ATTR_PTR(qgroups, enabled),
2153  	BTRFS_ATTR_PTR(qgroups, inconsistent),
2154  	BTRFS_ATTR_PTR(qgroups, drop_subtree_threshold),
2155  	NULL
2156  };
2157  ATTRIBUTE_GROUPS(qgroups);
2158  
qgroups_release(struct kobject * kobj)2159  static void qgroups_release(struct kobject *kobj)
2160  {
2161  	kfree(kobj);
2162  }
2163  
2164  static const struct kobj_type qgroups_ktype = {
2165  	.sysfs_ops = &kobj_sysfs_ops,
2166  	.default_groups = qgroups_groups,
2167  	.release = qgroups_release,
2168  };
2169  
qgroup_kobj_to_fs_info(struct kobject * kobj)2170  static inline struct btrfs_fs_info *qgroup_kobj_to_fs_info(struct kobject *kobj)
2171  {
2172  	return to_fs_info(kobj->parent->parent);
2173  }
2174  
2175  #define QGROUP_ATTR(_member, _show_name)					\
2176  static ssize_t btrfs_qgroup_show_##_member(struct kobject *qgroup_kobj,		\
2177  					   struct kobj_attribute *a,		\
2178  					   char *buf)				\
2179  {										\
2180  	struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);	\
2181  	struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,			\
2182  			struct btrfs_qgroup, kobj);				\
2183  	return btrfs_show_u64(&qgroup->_member, &fs_info->qgroup_lock, buf);	\
2184  }										\
2185  BTRFS_ATTR(qgroup, _show_name, btrfs_qgroup_show_##_member)
2186  
2187  #define QGROUP_RSV_ATTR(_name, _type)						\
2188  static ssize_t btrfs_qgroup_rsv_show_##_name(struct kobject *qgroup_kobj,	\
2189  					     struct kobj_attribute *a,		\
2190  					     char *buf)				\
2191  {										\
2192  	struct btrfs_fs_info *fs_info = qgroup_kobj_to_fs_info(qgroup_kobj);	\
2193  	struct btrfs_qgroup *qgroup = container_of(qgroup_kobj,			\
2194  			struct btrfs_qgroup, kobj);				\
2195  	return btrfs_show_u64(&qgroup->rsv.values[_type],			\
2196  			&fs_info->qgroup_lock, buf);				\
2197  }										\
2198  BTRFS_ATTR(qgroup, rsv_##_name, btrfs_qgroup_rsv_show_##_name)
2199  
2200  QGROUP_ATTR(rfer, referenced);
2201  QGROUP_ATTR(excl, exclusive);
2202  QGROUP_ATTR(max_rfer, max_referenced);
2203  QGROUP_ATTR(max_excl, max_exclusive);
2204  QGROUP_ATTR(lim_flags, limit_flags);
2205  QGROUP_RSV_ATTR(data, BTRFS_QGROUP_RSV_DATA);
2206  QGROUP_RSV_ATTR(meta_pertrans, BTRFS_QGROUP_RSV_META_PERTRANS);
2207  QGROUP_RSV_ATTR(meta_prealloc, BTRFS_QGROUP_RSV_META_PREALLOC);
2208  
2209  /*
2210   * Qgroup information.
2211   *
2212   * Path: /sys/fs/btrfs/<uuid>/qgroups/<level>_<qgroupid>/
2213   */
2214  static struct attribute *qgroup_attrs[] = {
2215  	BTRFS_ATTR_PTR(qgroup, referenced),
2216  	BTRFS_ATTR_PTR(qgroup, exclusive),
2217  	BTRFS_ATTR_PTR(qgroup, max_referenced),
2218  	BTRFS_ATTR_PTR(qgroup, max_exclusive),
2219  	BTRFS_ATTR_PTR(qgroup, limit_flags),
2220  	BTRFS_ATTR_PTR(qgroup, rsv_data),
2221  	BTRFS_ATTR_PTR(qgroup, rsv_meta_pertrans),
2222  	BTRFS_ATTR_PTR(qgroup, rsv_meta_prealloc),
2223  	NULL
2224  };
2225  ATTRIBUTE_GROUPS(qgroup);
2226  
qgroup_release(struct kobject * kobj)2227  static void qgroup_release(struct kobject *kobj)
2228  {
2229  	struct btrfs_qgroup *qgroup = container_of(kobj, struct btrfs_qgroup, kobj);
2230  
2231  	memset(&qgroup->kobj, 0, sizeof(*kobj));
2232  }
2233  
2234  static const struct kobj_type qgroup_ktype = {
2235  	.sysfs_ops = &kobj_sysfs_ops,
2236  	.release = qgroup_release,
2237  	.default_groups = qgroup_groups,
2238  };
2239  
btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info * fs_info,struct btrfs_qgroup * qgroup)2240  int btrfs_sysfs_add_one_qgroup(struct btrfs_fs_info *fs_info,
2241  				struct btrfs_qgroup *qgroup)
2242  {
2243  	struct kobject *qgroups_kobj = fs_info->qgroups_kobj;
2244  	int ret;
2245  
2246  	if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2247  		return 0;
2248  	if (qgroup->kobj.state_initialized)
2249  		return 0;
2250  	if (!qgroups_kobj)
2251  		return -EINVAL;
2252  
2253  	ret = kobject_init_and_add(&qgroup->kobj, &qgroup_ktype, qgroups_kobj,
2254  			"%hu_%llu", btrfs_qgroup_level(qgroup->qgroupid),
2255  			btrfs_qgroup_subvolid(qgroup->qgroupid));
2256  	if (ret < 0)
2257  		kobject_put(&qgroup->kobj);
2258  
2259  	return ret;
2260  }
2261  
btrfs_sysfs_del_qgroups(struct btrfs_fs_info * fs_info)2262  void btrfs_sysfs_del_qgroups(struct btrfs_fs_info *fs_info)
2263  {
2264  	struct btrfs_qgroup *qgroup;
2265  	struct btrfs_qgroup *next;
2266  
2267  	if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2268  		return;
2269  
2270  	rbtree_postorder_for_each_entry_safe(qgroup, next,
2271  					     &fs_info->qgroup_tree, node)
2272  		btrfs_sysfs_del_one_qgroup(fs_info, qgroup);
2273  	if (fs_info->qgroups_kobj) {
2274  		kobject_del(fs_info->qgroups_kobj);
2275  		kobject_put(fs_info->qgroups_kobj);
2276  		fs_info->qgroups_kobj = NULL;
2277  	}
2278  }
2279  
2280  /* Called when qgroups get initialized, thus there is no need for locking */
btrfs_sysfs_add_qgroups(struct btrfs_fs_info * fs_info)2281  int btrfs_sysfs_add_qgroups(struct btrfs_fs_info *fs_info)
2282  {
2283  	struct kobject *fsid_kobj = &fs_info->fs_devices->fsid_kobj;
2284  	struct btrfs_qgroup *qgroup;
2285  	struct btrfs_qgroup *next;
2286  	int ret = 0;
2287  
2288  	if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2289  		return 0;
2290  
2291  	ASSERT(fsid_kobj);
2292  	if (fs_info->qgroups_kobj)
2293  		return 0;
2294  
2295  	fs_info->qgroups_kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
2296  	if (!fs_info->qgroups_kobj)
2297  		return -ENOMEM;
2298  
2299  	ret = kobject_init_and_add(fs_info->qgroups_kobj, &qgroups_ktype,
2300  				   fsid_kobj, "qgroups");
2301  	if (ret < 0)
2302  		goto out;
2303  
2304  	rbtree_postorder_for_each_entry_safe(qgroup, next,
2305  					     &fs_info->qgroup_tree, node) {
2306  		ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
2307  		if (ret < 0)
2308  			goto out;
2309  	}
2310  
2311  out:
2312  	if (ret < 0)
2313  		btrfs_sysfs_del_qgroups(fs_info);
2314  	return ret;
2315  }
2316  
btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info * fs_info,struct btrfs_qgroup * qgroup)2317  void btrfs_sysfs_del_one_qgroup(struct btrfs_fs_info *fs_info,
2318  				struct btrfs_qgroup *qgroup)
2319  {
2320  	if (test_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state))
2321  		return;
2322  
2323  	if (qgroup->kobj.state_initialized) {
2324  		kobject_del(&qgroup->kobj);
2325  		kobject_put(&qgroup->kobj);
2326  	}
2327  }
2328  
2329  /*
2330   * Change per-fs features in /sys/fs/btrfs/UUID/features to match current
2331   * values in superblock. Call after any changes to incompat/compat_ro flags
2332   */
btrfs_sysfs_feature_update(struct btrfs_fs_info * fs_info)2333  void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info)
2334  {
2335  	struct kobject *fsid_kobj;
2336  	int ret;
2337  
2338  	if (!fs_info)
2339  		return;
2340  
2341  	fsid_kobj = &fs_info->fs_devices->fsid_kobj;
2342  	if (!fsid_kobj->state_initialized)
2343  		return;
2344  
2345  	ret = sysfs_update_group(fsid_kobj, &btrfs_feature_attr_group);
2346  	if (ret < 0)
2347  		btrfs_warn(fs_info,
2348  			   "failed to update /sys/fs/btrfs/%pU/features: %d",
2349  			   fs_info->fs_devices->fsid, ret);
2350  }
2351  
btrfs_init_sysfs(void)2352  int __init btrfs_init_sysfs(void)
2353  {
2354  	int ret;
2355  
2356  	btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
2357  	if (!btrfs_kset)
2358  		return -ENOMEM;
2359  
2360  	init_feature_attrs();
2361  	ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2362  	if (ret)
2363  		goto out2;
2364  	ret = sysfs_merge_group(&btrfs_kset->kobj,
2365  				&btrfs_static_feature_attr_group);
2366  	if (ret)
2367  		goto out_remove_group;
2368  
2369  #ifdef CONFIG_BTRFS_DEBUG
2370  	ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2371  	if (ret) {
2372  		sysfs_unmerge_group(&btrfs_kset->kobj,
2373  				    &btrfs_static_feature_attr_group);
2374  		goto out_remove_group;
2375  	}
2376  #endif
2377  
2378  	return 0;
2379  
2380  out_remove_group:
2381  	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2382  out2:
2383  	kset_unregister(btrfs_kset);
2384  
2385  	return ret;
2386  }
2387  
btrfs_exit_sysfs(void)2388  void __cold btrfs_exit_sysfs(void)
2389  {
2390  	sysfs_unmerge_group(&btrfs_kset->kobj,
2391  			    &btrfs_static_feature_attr_group);
2392  	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
2393  #ifdef CONFIG_BTRFS_DEBUG
2394  	sysfs_remove_group(&btrfs_kset->kobj, &btrfs_debug_feature_attr_group);
2395  #endif
2396  	kset_unregister(btrfs_kset);
2397  }
2398