From 1bae30982bc86ab66d61ccb6e22792593b45d44d Mon Sep 17 00:00:00 2001 From: David Sterba Date: Wed, 5 Feb 2014 15:36:18 +0100 Subject: [PATCH] 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: David Sterba Signed-off-by: Josef Bacik --- fs/btrfs/sysfs.c | 33 +++++++++++++++++++++++++++------ fs/btrfs/sysfs.h | 5 +++++ 2 files changed, 32 insertions(+), 6 deletions(-) diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 865f4cf9a769..c5eb2143dc66 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -24,6 +24,7 @@ #include #include #include +#include #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); } diff --git a/fs/btrfs/sysfs.h b/fs/btrfs/sysfs.h index f3cea3710d44..9ab576318a84 100644 --- a/fs/btrfs/sysfs.h +++ b/fs/btrfs/sysfs.h @@ -1,6 +1,11 @@ #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, -- 2.11.0