linux/fs/btrfs/sysfs.c
David Sterba ee17fc8005 btrfs: sysfs: protect reading label by lock
If the label setting ioctl races with sysfs label handler, we could get
mixed result in the output, part old part new. We should either get the
old or new label. The chances to hit this race are low.

Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06 15:22:49 +02:00

876 lines
22 KiB
C

/*
* Copyright (C) 2007 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/kobject.h>
#include <linux/bug.h>
#include <linux/genhd.h>
#include <linux/debugfs.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "sysfs.h"
#include "volumes.h"
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 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:
printk(KERN_WARNING "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 (fs_info->sb->s_flags & MS_RDONLY)
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(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_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(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(free_space_tree),
NULL
};
static const struct attribute_group btrfs_feature_attr_group = {
.name = "features",
.is_visible = btrfs_feature_visible,
.attrs = btrfs_supported_feature_attrs,
};
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(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(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_RAID_ATTR(total_bytes, raid_bytes_show);
BTRFS_RAID_ATTR(used_bytes, raid_bytes_show);
static ssize_t raid_bytes_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct btrfs_space_info *sinfo = to_space_info(kobj->parent);
struct btrfs_block_group_cache *block_group;
int index = to_raid_kobj(kobj)->raid_type;
u64 val = 0;
down_read(&sinfo->groups_sem);
list_for_each_entry(block_group, &sinfo->block_groups[index], list) {
if (&attr->attr == BTRFS_RAID_ATTR_PTR(total_bytes))
val += block_group->key.offset;
else
val += btrfs_block_group_used(&block_group->item);
}
up_read(&sinfo->groups_sem);
return snprintf(buf, PAGE_SIZE, "%llu\n", val);
}
static struct attribute *raid_attributes[] = {
BTRFS_RAID_ATTR_PTR(total_bytes),
BTRFS_RAID_ATTR_PTR(used_bytes),
NULL
};
static void release_raid_kobj(struct kobject *kobj)
{
kfree(to_raid_kobj(kobj));
}
struct kobj_type btrfs_raid_ktype = {
.sysfs_ops = &kobj_sysfs_ops,
.release = release_raid_kobj,
.default_attrs = raid_attributes,
};
#define SPACE_INFO_ATTR(field) \
static ssize_t btrfs_space_info_show_##field(struct kobject *kobj, \
struct kobj_attribute *a, \
char *buf) \
{ \
struct btrfs_space_info *sinfo = to_space_info(kobj); \
return btrfs_show_u64(&sinfo->field, &sinfo->lock, buf); \
} \
BTRFS_ATTR(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(disk_used);
SPACE_INFO_ATTR(disk_total);
BTRFS_ATTR(total_bytes_pinned, btrfs_space_info_show_total_bytes_pinned);
static struct attribute *space_info_attrs[] = {
BTRFS_ATTR_PTR(flags),
BTRFS_ATTR_PTR(total_bytes),
BTRFS_ATTR_PTR(bytes_used),
BTRFS_ATTR_PTR(bytes_pinned),
BTRFS_ATTR_PTR(bytes_reserved),
BTRFS_ATTR_PTR(bytes_may_use),
BTRFS_ATTR_PTR(disk_used),
BTRFS_ATTR_PTR(disk_total),
BTRFS_ATTR_PTR(total_bytes_pinned),
NULL,
};
static void space_info_release(struct kobject *kobj)
{
struct btrfs_space_info *sinfo = to_space_info(kobj);
percpu_counter_destroy(&sinfo->total_bytes_pinned);
kfree(sinfo);
}
struct kobj_type space_info_ktype = {
.sysfs_ops = &kobj_sysfs_ops,
.release = space_info_release,
.default_attrs = space_info_attrs,
};
static const struct attribute *allocation_attrs[] = {
BTRFS_ATTR_PTR(global_rsv_reserved),
BTRFS_ATTR_PTR(global_rsv_size),
NULL,
};
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 (fs_info->sb->s_flags & MS_RDONLY)
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 const struct attribute *btrfs_attrs[] = {
BTRFS_ATTR_PTR(label),
BTRFS_ATTR_PTR(nodesize),
BTRFS_ATTR_PTR(sectorsize),
BTRFS_ATTR_PTR(clone_alignment),
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
static char btrfs_unknown_feature_names[3][NUM_FEATURE_BITS][13];
static struct btrfs_feature_attr btrfs_feature_attrs[3][NUM_FEATURE_BITS];
static const u64 supported_feature_masks[3] = {
[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, 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);
}
const char * const btrfs_feature_set_names[3] = {
[FEAT_COMPAT] = "compat",
[FEAT_COMPAT_RO] = "compat_ro",
[FEAT_INCOMPAT] = "incompat",
};
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, 13, "%s:%u",
btrfs_feature_set_names[set], i);
fa->kobj_attr.attr.name = name;
fa->kobj_attr.attr.mode = S_IRUGO;
fa->feature_set = set;
fa->feature_bit = 1ULL << i;
}
}
}
/* 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)
fs_devs->device_dir_kobj = kobject_create_and_add("devices",
&fs_devs->fsid_kobj);
if (!fs_devs->device_dir_kobj)
return -ENOMEM;
return 0;
}
int btrfs_sysfs_add_device_link(struct btrfs_fs_devices *fs_devices,
struct btrfs_device *one_device)
{
int error = 0;
struct btrfs_device *dev;
list_for_each_entry(dev, &fs_devices->devices, dev_list) {
struct hd_struct *disk;
struct kobject *disk_kobj;
if (!dev->bdev)
continue;
if (one_device && one_device != dev)
continue;
disk = dev->bdev->bd_part;
disk_kobj = &part_to_dev(disk)->kobj;
error = sysfs_create_link(fs_devices->device_dir_kobj,
disk_kobj, disk_kobj->name);
if (error)
break;
}
return error;
}
/* /sys/fs/btrfs/ entry */
static struct kset *btrfs_kset;
/* /sys/kernel/debug/btrfs */
static struct dentry *btrfs_debugfs_root_dentry;
/* Debugging tunables and exported data */
u64 btrfs_debugfs_test;
/*
* Can be called by the device discovery thread.
* And parent can be specified for seed device
*/
int btrfs_sysfs_add_fsid(struct btrfs_fs_devices *fs_devs,
struct kobject *parent)
{
int error;
init_completion(&fs_devs->kobj_unregister);
fs_devs->fsid_kobj.kset = btrfs_kset;
error = kobject_init_and_add(&fs_devs->fsid_kobj,
&btrfs_ktype, parent, "%pU", fs_devs->fsid);
return error;
}
int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)
{
int error;
struct btrfs_fs_devices *fs_devs = fs_info->fs_devices;
struct kobject *fsid_kobj = &fs_devs->fsid_kobj;
btrfs_set_fs_info_ptr(fs_info);
error = btrfs_sysfs_add_device_link(fs_devs, NULL);
if (error)
return error;
error = sysfs_create_files(fsid_kobj, btrfs_attrs);
if (error) {
btrfs_sysfs_rm_device_link(fs_devs, NULL);
return error;
}
error = sysfs_create_group(fsid_kobj,
&btrfs_feature_attr_group);
if (error)
goto failure;
error = addrm_unknown_feature_attrs(fs_info, true);
if (error)
goto failure;
fs_info->space_info_kobj = kobject_create_and_add("allocation",
fsid_kobj);
if (!fs_info->space_info_kobj) {
error = -ENOMEM;
goto failure;
}
error = sysfs_create_files(fs_info->space_info_kobj, allocation_attrs);
if (error)
goto failure;
return 0;
failure:
btrfs_sysfs_remove_mounted(fs_info);
return error;
}
/*
* Change per-fs features in /sys/fs/btrfs/UUID/features to match current
* values in superblock. Call after any changes to incompat/compat_ro flags
*/
void btrfs_sysfs_feature_update(struct btrfs_fs_info *fs_info,
u64 bit, enum btrfs_feature_set set)
{
struct btrfs_fs_devices *fs_devs;
struct kobject *fsid_kobj;
u64 features;
int ret;
if (!fs_info)
return;
features = get_features(fs_info, set);
ASSERT(bit & supported_feature_masks[set]);
fs_devs = fs_info->fs_devices;
fsid_kobj = &fs_devs->fsid_kobj;
if (!fsid_kobj->state_initialized)
return;
/*
* FIXME: this is too heavy to update just one value, ideally we'd like
* to use sysfs_update_group but some refactoring is needed first.
*/
sysfs_remove_group(fsid_kobj, &btrfs_feature_attr_group);
ret = sysfs_create_group(fsid_kobj, &btrfs_feature_attr_group);
}
static int btrfs_init_debugfs(void)
{
#ifdef CONFIG_DEBUG_FS
btrfs_debugfs_root_dentry = debugfs_create_dir("btrfs", NULL);
if (!btrfs_debugfs_root_dentry)
return -ENOMEM;
debugfs_create_u64("test", S_IRUGO | S_IWUGO, btrfs_debugfs_root_dentry,
&btrfs_debugfs_test);
#endif
return 0;
}
int btrfs_init_sysfs(void)
{
int ret;
btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
if (!btrfs_kset)
return -ENOMEM;
ret = btrfs_init_debugfs();
if (ret)
goto out1;
init_feature_attrs();
ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
if (ret)
goto out2;
return 0;
out2:
debugfs_remove_recursive(btrfs_debugfs_root_dentry);
out1:
kset_unregister(btrfs_kset);
return ret;
}
void btrfs_exit_sysfs(void)
{
sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
kset_unregister(btrfs_kset);
debugfs_remove_recursive(btrfs_debugfs_root_dentry);
}