Commit 1bae3098 authored by David Sterba's avatar David Sterba Committed by Josef Bacik
Browse files

btrfs: add simple debugfs interface 



Help during debugging to export various interesting infromation and
tunables without the need of extra mount options or ioctls.

Usage:
* declare your variable in sysfs.h, and include where you need it
* define the variable in sysfs.c and make it visible via
  debugfs_create_TYPE

Depends on CONFIG_DEBUG_FS.

Signed-off-by: default avatarDavid Sterba <dsterba@suse.cz>
Signed-off-by: default avatarJosef Bacik <jbacik@fb.com>
parent ace01050

fs/btrfs/sysfs.c

+27 −6
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include <linux/kobject.h>

#include <linux/bug.h>

#include <linux/genhd.h>

#include <linux/debugfs.h>



#include "ctree.h"

#include "disk-io.h"
@@ -599,6 +600,12 @@ static int add_device_membership(struct btrfs_fs_info *fs_info) 
/* /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;



int btrfs_sysfs_add_one(struct btrfs_fs_info *fs_info)

{

	int error;
@@ -642,27 +649,41 @@ failure: 
	return error;

}



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;



	init_feature_attrs();

	ret = btrfs_init_debugfs();

	if (ret)

		return ret;



	init_feature_attrs();

	ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);

	if (ret) {

		kset_unregister(btrfs_kset);

		return ret;

	}



	return 0;

	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);

}

fs/btrfs/sysfs.h

+5 −0
Original line number Diff line number Diff line 
#ifndef _BTRFS_SYSFS_H_

#define _BTRFS_SYSFS_H_



/*

 * Data exported through sysfs

 */

extern u64 btrfs_debugfs_test;



enum btrfs_feature_set {

	FEAT_COMPAT,

	FEAT_COMPAT_RO,

CRA Git | Maintained and supported by SUSTech CRA and CCSE