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sysfs.c
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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2007 Oracle. All rights reserved.
*/
#include <linux/sched.h>
#include <linux/sched/mm.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/bug.h>
#include <crypto/hash.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "sysfs.h"
#include "volumes.h"
#include "space-info.h"
#include "block-group.h"
struct btrfs_feature_attr {
struct kobj_attribute kobj_attr;
enum btrfs_feature_set feature_set;
u64 feature_bit;
};
/* For raid type sysfs entries */
struct raid_kobject {
u64 flags;
struct kobject kobj;
};
#define __INIT_KOBJ_ATTR(_name, _mode, _show, _store) \
{ \
.attr = { .name = __stringify(_name), .mode = _mode }, \
.show = _show, \
.store = _store, \
}
#define BTRFS_ATTR_RW(_prefix, _name, _show, _store) \
static struct kobj_attribute btrfs_attr_##_prefix##_##_name = \
__INIT_KOBJ_ATTR(_name, 0644, _show, _store)
#define BTRFS_ATTR(_prefix, _name, _show) \
static struct kobj_attribute btrfs_attr_##_prefix##_##_name = \
__INIT_KOBJ_ATTR(_name, 0444, _show, NULL)
#define BTRFS_ATTR_PTR(_prefix, _name) \
(&btrfs_attr_##_prefix##_##_name.attr)
#define BTRFS_FEAT_ATTR(_name, _feature_set, _feature_prefix, _feature_bit) \
static struct btrfs_feature_attr btrfs_attr_features_##_name = { \
.kobj_attr = __INIT_KOBJ_ATTR(_name, S_IRUGO, \
btrfs_feature_attr_show, \
btrfs_feature_attr_store), \
.feature_set = _feature_set, \
.feature_bit = _feature_prefix ##_## _feature_bit, \
}
#define BTRFS_FEAT_ATTR_PTR(_name) \
(&btrfs_attr_features_##_name.kobj_attr.attr)
#define BTRFS_FEAT_ATTR_COMPAT(name, feature) \
BTRFS_FEAT_ATTR(name, FEAT_COMPAT, BTRFS_FEATURE_COMPAT, feature)
#define BTRFS_FEAT_ATTR_COMPAT_RO(name, feature) \
BTRFS_FEAT_ATTR(name, FEAT_COMPAT_RO, BTRFS_FEATURE_COMPAT_RO, feature)
#define BTRFS_FEAT_ATTR_INCOMPAT(name, feature) \
BTRFS_FEAT_ATTR(name, FEAT_INCOMPAT, BTRFS_FEATURE_INCOMPAT, feature)
static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj);
static struct btrfs_feature_attr *to_btrfs_feature_attr(struct kobj_attribute *a)
{
return container_of(a, struct btrfs_feature_attr, kobj_attr);
}
static struct kobj_attribute *attr_to_btrfs_attr(struct attribute *attr)
{
return container_of(attr, struct kobj_attribute, attr);
}
static struct btrfs_feature_attr *attr_to_btrfs_feature_attr(
struct attribute *attr)
{
return to_btrfs_feature_attr(attr_to_btrfs_attr(attr));
}
static u64 get_features(struct btrfs_fs_info *fs_info,
enum btrfs_feature_set set)
{
struct btrfs_super_block *disk_super = fs_info->super_copy;
if (set == FEAT_COMPAT)
return btrfs_super_compat_flags(disk_super);
else if (set == FEAT_COMPAT_RO)
return btrfs_super_compat_ro_flags(disk_super);
else
return btrfs_super_incompat_flags(disk_super);
}
static void set_features(struct btrfs_fs_info *fs_info,
enum btrfs_feature_set set, u64 features)
{
struct btrfs_super_block *disk_super = fs_info->super_copy;
if (set == FEAT_COMPAT)
btrfs_set_super_compat_flags(disk_super, features);
else if (set == FEAT_COMPAT_RO)
btrfs_set_super_compat_ro_flags(disk_super, features);
else
btrfs_set_super_incompat_flags(disk_super, features);
}
static int can_modify_feature(struct btrfs_feature_attr *fa)
{
int val = 0;
u64 set, clear;
switch (fa->feature_set) {
case FEAT_COMPAT:
set = BTRFS_FEATURE_COMPAT_SAFE_SET;
clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
break;
case FEAT_COMPAT_RO:
set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
break;
case FEAT_INCOMPAT:
set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
break;
default:
pr_warn("btrfs: sysfs: unknown feature set %d\n",
fa->feature_set);
return 0;
}
if (set & fa->feature_bit)
val |= 1;
if (clear & fa->feature_bit)
val |= 2;
return val;
}
static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
struct kobj_attribute *a, char *buf)
{
int val = 0;
struct btrfs_fs_info *fs_info = to_fs_info(kobj);
struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
if (fs_info) {
u64 features = get_features(fs_info, fa->feature_set);
if (features & fa->feature_bit)
val = 1;
} else
val = can_modify_feature(fa);
return snprintf(buf, PAGE_SIZE, "%d\n", val);
}
static ssize_t btrfs_feature_attr_store(struct kobject *kobj,
struct kobj_attribute *a,
const char *buf, size_t count)
{
struct btrfs_fs_info *fs_info;
struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
u64 features, set, clear;
unsigned long val;
int ret;
fs_info = to_fs_info(kobj);
if (!fs_info)
return -EPERM;
if (sb_rdonly(fs_info->sb))
return -EROFS;
ret = kstrtoul(skip_spaces(buf), 0, &val);
if (ret)
return ret;
if (fa->feature_set == FEAT_COMPAT) {
set = BTRFS_FEATURE_COMPAT_SAFE_SET;
clear = BTRFS_FEATURE_COMPAT_SAFE_CLEAR;
} else if (fa->feature_set == FEAT_COMPAT_RO) {
set = BTRFS_FEATURE_COMPAT_RO_SAFE_SET;
clear = BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR;
} else {
set = BTRFS_FEATURE_INCOMPAT_SAFE_SET;
clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
}
features = get_features(fs_info, fa->feature_set);
/* Nothing to do */
if ((val && (features & fa->feature_bit)) ||
(!val && !(features & fa->feature_bit)))
return count;
if ((val && !(set & fa->feature_bit)) ||
(!val && !(clear & fa->feature_bit))) {
btrfs_info(fs_info,
"%sabling feature %s on mounted fs is not supported.",
val ? "En" : "Dis", fa->kobj_attr.attr.name);
return -EPERM;
}
btrfs_info(fs_info, "%s %s feature flag",
val ? "Setting" : "Clearing", fa->kobj_attr.attr.name);
spin_lock(&fs_info->super_lock);
features = get_features(fs_info, fa->feature_set);
if (val)
features |= fa->feature_bit;
else
features &= ~fa->feature_bit;
set_features(fs_info, fa->feature_set, features);
spin_unlock(&fs_info->super_lock);
/*
* We don't want to do full transaction commit from inside sysfs
*/
btrfs_set_pending(fs_info, COMMIT);
wake_up_process(fs_info->transaction_kthread);
return count;
}
static umode_t btrfs_feature_visible(struct kobject *kobj,
struct attribute *attr, int unused)
{
struct btrfs_fs_info *fs_info = to_fs_info(kobj);
umode_t mode = attr->mode;
if (fs_info) {
struct btrfs_feature_attr *fa;
u64 features;
fa = attr_to_btrfs_feature_attr(attr);
features = get_features(fs_info, fa->feature_set);
if (can_modify_feature(fa))
mode |= S_IWUSR;
else if (!(features & fa->feature_bit))
mode = 0;
}
return mode;
}
BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF);
BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
BTRFS_FEAT_ATTR_INCOMPAT(compress_zstd, COMPRESS_ZSTD);
BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA);
BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES);
BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID);
BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE);
static struct attribute *btrfs_supported_feature_attrs[] = {
BTRFS_FEAT_ATTR_PTR(mixed_backref),
BTRFS_FEAT_ATTR_PTR(default_subvol),
BTRFS_FEAT_ATTR_PTR(mixed_groups),
BTRFS_FEAT_ATTR_PTR(compress_lzo),
BTRFS_FEAT_ATTR_PTR(compress_zstd),
BTRFS_FEAT_ATTR_PTR(big_metadata),
BTRFS_FEAT_ATTR_PTR(extended_iref),
BTRFS_FEAT_ATTR_PTR(raid56),
BTRFS_FEAT_ATTR_PTR(skinny_metadata),
BTRFS_FEAT_ATTR_PTR(no_holes),
BTRFS_FEAT_ATTR_PTR(metadata_uuid),
BTRFS_FEAT_ATTR_PTR(free_space_tree),
NULL
};
/*
* Features which depend on feature bits and may differ between each fs.
*
* /sys/fs/btrfs/features lists all available features of this kernel while
* /sys/fs/btrfs/UUID/features shows features of the fs which are enabled or
* can be changed online.
*/
static const struct attribute_group btrfs_feature_attr_group = {
.name = "features",
.is_visible = btrfs_feature_visible,
.attrs = btrfs_supported_feature_attrs,
};
static ssize_t rmdir_subvol_show(struct kobject *kobj,
struct kobj_attribute *ka, char *buf)
{
return snprintf(buf, PAGE_SIZE, "0\n");
}
BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
static ssize_t supported_checksums_show(struct kobject *kobj,
struct kobj_attribute *a, char *buf)
{
ssize_t ret = 0;
int i;
for (i = 0; i < btrfs_get_num_csums(); i++) {
/*
* This "trick" only works as long as 'enum btrfs_csum_type' has
* no holes in it
*/
ret += snprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
(i == 0 ? "" : " "), btrfs_super_csum_name(i));
}
ret += snprintf(buf + ret, PAGE_SIZE - ret, "\n");
return ret;
}
BTRFS_ATTR(static_feature, supported_checksums, supported_checksums_show);
static struct attribute *btrfs_supported_static_feature_attrs[] = {
BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
BTRFS_ATTR_PTR(static_feature, supported_checksums),
NULL
};
/*
* Features which only depend on kernel version.
*
* These are listed in /sys/fs/btrfs/features along with
* btrfs_feature_attr_group
*/
static const struct attribute_group btrfs_static_feature_attr_group = {
.name = "features",
.attrs = btrfs_supported_static_feature_attrs,
};
#ifdef CONFIG_BTRFS_DEBUG
/*
* Runtime debugging exported via sysfs
*
* /sys/fs/btrfs/debug - applies to module or all filesystems
* /sys/fs/btrfs/UUID - applies only to the given filesystem
*/
static struct attribute *btrfs_debug_feature_attrs[] = {
NULL
};
static const struct attribute_group btrfs_debug_feature_attr_group = {
.name = "debug",
.attrs = btrfs_debug_feature_attrs,
};
#endif
static ssize_t btrfs_show_u64(u64 *value_ptr, spinlock_t *lock, char *buf)
{
u64 val;
if (lock)
spin_lock(lock);
val = *value_ptr;
if (lock)
spin_unlock(lock);
return snprintf(buf, PAGE_SIZE, "%llu\n", val);
}
static ssize_t global_rsv_size_show(struct kobject *kobj,
struct kobj_attribute *ka, char *buf)
{
struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
return btrfs_show_u64(&block_rsv->size, &block_rsv->lock, buf);
}
BTRFS_ATTR(allocation, global_rsv_size, global_rsv_size_show);
static ssize_t global_rsv_reserved_show(struct kobject *kobj,
struct kobj_attribute *a, char *buf)
{
struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent);
struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
return btrfs_show_u64(&block_rsv->reserved, &block_rsv->lock, buf);
}
BTRFS_ATTR(allocation, global_rsv_reserved, global_rsv_reserved_show);
#define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj)
#define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj)
static ssize_t raid_bytes_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf);
BTRFS_ATTR(raid, total_bytes, raid_bytes_show);
BTRFS_ATTR(raid, used_bytes, raid_bytes_show);
static ssize_t raid_bytes_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
struct btrfs_block_group_cache *block_group;
int index = btrfs_bg_flags_to_raid_index(to_raid_kobj(kobj)->flags);
u64 val = 0;
down_read(&sinfo->groups_sem);
list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
if (&attr->attr == BTRFS_ATTR_PTR(raid, total_bytes))
val += block_group->key.offset;
else
val += block_group->used;
}
up_read(&sinfo->groups_sem);
return snprintf(buf, PAGE_SIZE, "%llu\n", val);
}
static struct attribute *raid_attrs[] = {
BTRFS_ATTR_PTR(raid, total_bytes),
BTRFS_ATTR_PTR(raid, used_bytes),
NULL
};
ATTRIBUTE_GROUPS(raid);
static void release_raid_kobj(struct kobject *kobj)
{
kfree(to_raid_kobj(kobj));
}
static struct kobj_type btrfs_raid_ktype = {
.sysfs_ops = &kobj_sysfs_ops,
.release = release_raid_kobj,
.default_groups = raid_groups,
};
#define SPACE_INFO_ATTR(field) \
static ssize_t btrfs_space_info_show_##field(struct kobject *kobj, \
struct kobj_attribute *a, \
char *buf) \
{ \
struct btrfs_space_info *sinfo = to_space_info(kobj); \
return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf); \
} \
BTRFS_ATTR(space_info, field, btrfs_space_info_show_##field)
static ssize_t btrfs_space_info_show_total_bytes_pinned(struct kobject *kobj,
struct kobj_attribute *a,
char *buf)
{
struct btrfs_space_info *sinfo = to_space_info(kobj);
s64 val = percpu_counter_sum(&sinfo->total_bytes_pinned);
return snprintf(buf, PAGE_SIZE, "%lld\n", val);
}
SPACE_INFO_ATTR(flags);
SPACE_INFO_ATTR(total_bytes);
SPACE_INFO_ATTR(bytes_used);
SPACE_INFO_ATTR(bytes_pinned);
SPACE_INFO_ATTR(bytes_reserved);
SPACE_INFO_ATTR(bytes_may_use);
SPACE_INFO_ATTR(bytes_readonly);
SPACE_INFO_ATTR(disk_used);
SPACE_INFO_ATTR(disk_total);
BTRFS_ATTR(space_info, total_bytes_pinned,
btrfs_space_info_show_total_bytes_pinned);
static struct attribute *space_info_attrs[] = {
BTRFS_ATTR_PTR(space_info, flags),
BTRFS_ATTR_PTR(space_info, total_bytes),
BTRFS_ATTR_PTR(space_info, bytes_used),
BTRFS_ATTR_PTR(space_info, bytes_pinned),
BTRFS_ATTR_PTR(space_info, bytes_reserved),
BTRFS_ATTR_PTR(space_info, bytes_may_use),
BTRFS_ATTR_PTR(space_info, bytes_readonly),
BTRFS_ATTR_PTR(space_info, disk_used),
BTRFS_ATTR_PTR(space_info, disk_total),
BTRFS_ATTR_PTR(space_info, total_bytes_pinned),
NULL,
};
ATTRIBUTE_GROUPS(space_info);
static void space_info_release(struct kobject *kobj)
{
struct btrfs_space_info *sinfo = to_space_info(kobj);
percpu_counter_destroy(&sinfo->total_bytes_pinned);
kfree(sinfo);
}
static struct kobj_type space_info_ktype = {
.sysfs_ops = &kobj_sysfs_ops,
.release = space_info_release,
.default_groups = space_info_groups,
};
static const struct attribute *allocation_attrs[] = {
BTRFS_ATTR_PTR(allocation, global_rsv_reserved),
BTRFS_ATTR_PTR(allocation, global_rsv_size),
NULL,
};
static ssize_t btrfs_label_show(struct kobject *kobj,
struct kobj_attribute *a, char *buf)
{
struct btrfs_fs_info *fs_info = to_fs_info(kobj);
char *label = fs_info->super_copy->label;
ssize_t ret;
spin_lock(&fs_info->super_lock);
ret = snprintf(buf, PAGE_SIZE, label[0] ? "%s\n" : "%s", label);
spin_unlock(&fs_info->super_lock);
return ret;
}
static ssize_t btrfs_label_store(struct kobject *kobj,
struct kobj_attribute *a,
const char *buf, size_t len)
{
struct btrfs_fs_info *fs_info = to_fs_info(kobj);
size_t p_len;
if (!fs_info)
return -EPERM;
if (sb_rdonly(fs_info->sb))
return -EROFS;
/*
* p_len is the len until the first occurrence of either
* '\n' or '\0'
*/
p_len = strcspn(buf, "\n");
if (p_len >= BTRFS_LABEL_SIZE)
return -EINVAL;
spin_lock(&fs_info->super_lock);
memset(fs_info->super_copy->label, 0, BTRFS_LABEL_SIZE);
memcpy(fs_info->super_copy->label, buf, p_len);
spin_unlock(&fs_info->super_lock);
/*
* We don't want to do full transaction commit from inside sysfs
*/
btrfs_set_pending(fs_info, COMMIT);
wake_up_process(fs_info->transaction_kthread);
return len;
}
BTRFS_ATTR_RW(, label, btrfs_label_show, btrfs_label_store);
static ssize_t btrfs_nodesize_show(struct kobject *kobj,
struct kobj_attribute *a, char *buf)
{
struct btrfs_fs_info *fs_info = to_fs_info(kobj);
return snprintf(buf, PAGE_SIZE, "%u\n", fs_info->super_copy->nodesize);
}
BTRFS_ATTR(, nodesize, btrfs_nodesize_show);
static ssize_t btrfs_sectorsize_show(struct kobject *kobj,
struct kobj_attribute *a, char *buf)
{
struct btrfs_fs_info *fs_info = to_fs_info(kobj);
return snprintf(buf, PAGE_SIZE, "%u\n",
fs_info->super_copy->sectorsize);
}
BTRFS_ATTR(, sectorsize, btrfs_sectorsize_show);
static ssize_t btrfs_clone_alignment_show(struct kobject *kobj,
struct kobj_attribute *a, char *buf)
{
struct btrfs_fs_info *fs_info = to_fs_info(kobj);
return snprintf(buf, PAGE_SIZE, "%u\n",
fs_info->super_copy->sectorsize);
}
BTRFS_ATTR(, clone_alignment, btrfs_clone_alignment_show);
static ssize_t quota_override_show(struct kobject *kobj,
struct kobj_attribute *a, char *buf)
{
struct btrfs_fs_info *fs_info = to_fs_info(kobj);
int quota_override;
quota_override = test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
return snprintf(buf, PAGE_SIZE, "%d\n", quota_override);
}
static ssize_t quota_override_store(struct kobject *kobj,
struct kobj_attribute *a,
const char *buf, size_t len)
{
struct btrfs_fs_info *fs_info = to_fs_info(kobj);
unsigned long knob;
int err;
if (!fs_info)
return -EPERM;
if (!capable(CAP_SYS_RESOURCE))
return -EPERM;
err = kstrtoul(buf, 10, &knob);
if (err)
return err;
if (knob > 1)
return -EINVAL;
if (knob)
set_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
else
clear_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags);
return len;
}
BTRFS_ATTR_RW(, quota_override, quota_override_show, quota_override_store);
static ssize_t btrfs_metadata_uuid_show(struct kobject *kobj,
struct kobj_attribute *a, char *buf)
{
struct btrfs_fs_info *fs_info = to_fs_info(kobj);
return snprintf(buf, PAGE_SIZE, "%pU\n",
fs_info->fs_devices->metadata_uuid);
}
BTRFS_ATTR(, metadata_uuid, btrfs_metadata_uuid_show);
static ssize_t btrfs_checksum_show(struct kobject *kobj,
struct kobj_attribute *a, char *buf)
{
struct btrfs_fs_info *fs_info = to_fs_info(kobj);
u16 csum_type = btrfs_super_csum_type(fs_info->super_copy);
return snprintf(buf, PAGE_SIZE, "%s (%s)\n",
btrfs_super_csum_name(csum_type),
crypto_shash_driver_name(fs_info->csum_shash));
}
BTRFS_ATTR(, checksum, btrfs_checksum_show);
static const struct attribute *btrfs_attrs[] = {
BTRFS_ATTR_PTR(, label),
BTRFS_ATTR_PTR(, nodesize),
BTRFS_ATTR_PTR(, sectorsize),
BTRFS_ATTR_PTR(, clone_alignment),
BTRFS_ATTR_PTR(, quota_override),
BTRFS_ATTR_PTR(, metadata_uuid),
BTRFS_ATTR_PTR(, checksum),
NULL,
};
static void btrfs_release_fsid_kobj(struct kobject *kobj)
{
struct btrfs_fs_devices *fs_devs = to_fs_devs(kobj);
memset(&fs_devs->fsid_kobj, 0, sizeof(struct kobject));
complete(&fs_devs->kobj_unregister);
}
static struct kobj_type btrfs_ktype = {
.sysfs_ops = &kobj_sysfs_ops,
.release = btrfs_release_fsid_kobj,
};
static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj)
{
if (kobj->ktype != &btrfs_ktype)
return NULL;
return container_of(kobj, struct btrfs_fs_devices, fsid_kobj);
}
static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
{
if (kobj->ktype != &btrfs_ktype)
return NULL;
return to_fs_devs(kobj)->fs_info;
}
#define NUM_FEATURE_BITS 64
#define BTRFS_FEATURE_NAME_MAX 13
static char btrfs_unknown_feature_names[FEAT_MAX][NUM_FEATURE_BITS][BTRFS_FEATURE_NAME_MAX];
static struct btrfs_feature_attr btrfs_feature_attrs[FEAT_MAX][NUM_FEATURE_BITS];
static const u64 supported_feature_masks[FEAT_MAX] = {
[FEAT_COMPAT] = BTRFS_FEATURE_COMPAT_SUPP,
[FEAT_COMPAT_RO] = BTRFS_FEATURE_COMPAT_RO_SUPP,
[FEAT_INCOMPAT] = BTRFS_FEATURE_INCOMPAT_SUPP,
};
static int addrm_unknown_feature_attrs(struct btrfs_fs_info *fs_info, bool add)
{
int set;
for (set = 0; set < FEAT_MAX; set++) {
int i;
struct attribute *attrs[2];
struct attribute_group agroup = {
.name = "features",
.attrs = attrs,
};
u64 features = get_features(fs_info, set);
features &= ~supported_feature_masks[set];
if (!features)
continue;
attrs[1] = NULL;
for (i = 0; i < NUM_FEATURE_BITS; i++) {
struct btrfs_feature_attr *fa;
if (!(features & (1ULL << i)))
continue;
fa = &btrfs_feature_attrs[set][i];
attrs[0] = &fa->kobj_attr.attr;
if (add) {
int ret;
ret = sysfs_merge_group(&fs_info->fs_devices->fsid_kobj,
&agroup);
if (ret)
return ret;
} else
sysfs_unmerge_group(&fs_info->fs_devices->fsid_kobj,
&agroup);
}
}
return 0;
}
static void __btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
{
if (fs_devs->device_dir_kobj) {
kobject_del(fs_devs->device_dir_kobj);
kobject_put(fs_devs->device_dir_kobj);
fs_devs->device_dir_kobj = NULL;
}
if (fs_devs->fsid_kobj.state_initialized) {
kobject_del(&fs_devs->fsid_kobj);
kobject_put(&fs_devs->fsid_kobj);
wait_for_completion(&fs_devs->kobj_unregister);
}
}
/* when fs_devs is NULL it will remove all fsid kobject */
void btrfs_sysfs_remove_fsid(struct btrfs_fs_devices *fs_devs)
{
struct list_head *fs_uuids = btrfs_get_fs_uuids();
if (fs_devs) {
__btrfs_sysfs_remove_fsid(fs_devs);
return;
}
list_for_each_entry(fs_devs, fs_uuids, fs_list) {
__btrfs_sysfs_remove_fsid(fs_devs);
}
}
void btrfs_sysfs_remove_mounted(struct btrfs_fs_info *fs_info)
{
btrfs_reset_fs_info_ptr(fs_info);
if (fs_info->space_info_kobj) {
sysfs_remove_files(fs_info->space_info_kobj, allocation_attrs);
kobject_del(fs_info->space_info_kobj);
kobject_put(fs_info->space_info_kobj);
}
addrm_unknown_feature_attrs(fs_info, false);
sysfs_remove_group(&fs_info->fs_devices->fsid_kobj, &btrfs_feature_attr_group);
sysfs_remove_files(&fs_info->fs_devices->fsid_kobj, btrfs_attrs);
btrfs_sysfs_rm_device_link(fs_info->fs_devices, NULL);
}
static const char * const btrfs_feature_set_names[FEAT_MAX] = {
[FEAT_COMPAT] = "compat",
[FEAT_COMPAT_RO] = "compat_ro",
[FEAT_INCOMPAT] = "incompat",
};
const char * const btrfs_feature_set_name(enum btrfs_feature_set set)
{
return btrfs_feature_set_names[set];
}
char *btrfs_printable_features(enum btrfs_feature_set set, u64 flags)
{
size_t bufsize = 4096; /* safe max, 64 names * 64 bytes */
int len = 0;
int i;
char *str;
str = kmalloc(bufsize, GFP_KERNEL);
if (!str)
return str;
for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
const char *name;
if (!(flags & (1ULL << i)))
continue;
name = btrfs_feature_attrs[set][i].kobj_attr.attr.name;
len += snprintf(str + len, bufsize - len, "%s%s",
len ? "," : "", name);
}
return str;
}
static void init_feature_attrs(void)
{
struct btrfs_feature_attr *fa;
int set, i;
BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names) !=
ARRAY_SIZE(btrfs_feature_attrs));
BUILD_BUG_ON(ARRAY_SIZE(btrfs_unknown_feature_names[0]) !=
ARRAY_SIZE(btrfs_feature_attrs[0]));
memset(btrfs_feature_attrs, 0, sizeof(btrfs_feature_attrs));
memset(btrfs_unknown_feature_names, 0,
sizeof(btrfs_unknown_feature_names));
for (i = 0; btrfs_supported_feature_attrs[i]; i++) {
struct btrfs_feature_attr *sfa;
struct attribute *a = btrfs_supported_feature_attrs[i];
int bit;
sfa = attr_to_btrfs_feature_attr(a);
bit = ilog2(sfa->feature_bit);
fa = &btrfs_feature_attrs[sfa->feature_set][bit];
fa->kobj_attr.attr.name = sfa->kobj_attr.attr.name;
}
for (set = 0; set < FEAT_MAX; set++) {
for (i = 0; i < ARRAY_SIZE(btrfs_feature_attrs[set]); i++) {
char *name = btrfs_unknown_feature_names[set][i];
fa = &btrfs_feature_attrs[set][i];
if (fa->kobj_attr.attr.name)
continue;
snprintf(name, BTRFS_FEATURE_NAME_MAX, "%s:%u",
btrfs_feature_set_names[set], i);
fa->kobj_attr.attr.name = name;
fa->kobj_attr.attr.mode = S_IRUGO;
fa->feature_set = set;
fa->feature_bit = 1ULL << i;
}
}
}
/*
* Create a sysfs entry for a given block group type at path
* /sys/fs/btrfs/UUID/allocation/data/TYPE
*/
void btrfs_sysfs_add_block_group_type(struct btrfs_block_group_cache *cache)
{
struct btrfs_fs_info *fs_info = cache->fs_info;
struct btrfs_space_info *space_info = cache->space_info;
struct raid_kobject *rkobj;
const int index = btrfs_bg_flags_to_raid_index(cache->flags);
unsigned int nofs_flag;
int ret;
/*
* Setup a NOFS context because kobject_add(), deep in its call chain,
* does GFP_KERNEL allocations, and we are often called in a context
* where if reclaim is triggered we can deadlock (we are either holding
* a transaction handle or some lock required for a transaction
* commit).
*/
nofs_flag = memalloc_nofs_save();
rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
if (!rkobj) {
memalloc_nofs_restore(nofs_flag);
btrfs_warn(cache->fs_info,
"couldn't alloc memory for raid level kobject");
return;
}
rkobj->flags = cache->flags;
kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
ret = kobject_add(&rkobj->kobj, &space_info->kobj, "%s",
btrfs_bg_type_to_raid_name(rkobj->flags));
memalloc_nofs_restore(nofs_flag);
if (ret) {
kobject_put(&rkobj->kobj);
btrfs_warn(fs_info,
"failed to add kobject for block cache, ignoring");
return;
}
space_info->block_group_kobjs[index] = &rkobj->kobj;
}
/*
* Remove sysfs directories for all block group types of a given space info and
* the space info as well
*/
void btrfs_sysfs_remove_space_info(struct btrfs_space_info *space_info)
{
int i;
for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
struct kobject *kobj;
kobj = space_info->block_group_kobjs[i];
space_info->block_group_kobjs[i] = NULL;
if (kobj) {
kobject_del(kobj);
kobject_put(kobj);
}
}
kobject_del(&space_info->kobj);
kobject_put(&space_info->kobj);
}
static const char *alloc_name(u64 flags)
{
switch (flags) {
case BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA:
return "mixed";
case BTRFS_BLOCK_GROUP_METADATA:
return "metadata";
case BTRFS_BLOCK_GROUP_DATA:
return "data";
case BTRFS_BLOCK_GROUP_SYSTEM:
return "system";
default:
WARN_ON(1);
return "invalid-combination";
};
}
/*
* Create a sysfs entry for a space info type at path
* /sys/fs/btrfs/UUID/allocation/TYPE
*/
int btrfs_sysfs_add_space_info_type(struct btrfs_fs_info *fs_info,
struct btrfs_space_info *space_info)
{
int ret;
ret = kobject_init_and_add(&space_info->kobj, &space_info_ktype,
fs_info->space_info_kobj, "%s",
alloc_name(space_info->flags));
if (ret) {
kobject_put(&space_info->kobj);
return ret;
}
return 0;
}
/* when one_device is NULL, it removes all device links */
int btrfs_sysfs_rm_device_link(struct btrfs_fs_devices *fs_devices,
struct btrfs_device *one_device)
{
struct hd_struct *disk;
struct kobject *disk_kobj;
if (!fs_devices->device_dir_kobj)
return -EINVAL;
if (one_device && one_device->bdev) {
disk = one_device->bdev->bd_part;
disk_kobj = &part_to_dev(disk)->kobj;
sysfs_remove_link(fs_devices->device_dir_kobj,
disk_kobj->name);
}
if (one_device)
return 0;
list_for_each_entry(one_device,
&fs_devices->devices, dev_list) {
if (!one_device->bdev)
continue;
disk = one_device->bdev->bd_part;
disk_kobj = &part_to_dev(disk)->kobj;
sysfs_remove_link(fs_devices->device_dir_kobj,
disk_kobj->name);
}
return 0;
}
int btrfs_sysfs_add_device(struct btrfs_fs_devices *fs_devs)
{
if (!fs_devs->device_dir_kobj)