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Commit 510d7360 authored by Jeff Mahoney's avatar Jeff Mahoney Committed by Chris Mason
Browse files

btrfs: publish per-super features in sysfs 



This patch publishes information on which features are enabled in the
file system on a per-super basis. At this point, it only publishes
information on features supported by the file system implementation.

Signed-off-by: default avatarJeff Mahoney <jeffm@suse.com>
Signed-off-by: default avatarJosef Bacik <jbacik@fusionio.com>
Signed-off-by: default avatarChris Mason <clm@fb.com>
parent 5ac1d209

fs/btrfs/sysfs.c

+65 −16
Original line number Diff line number Diff line
@@ -28,29 +28,53 @@ 
#include "transaction.h"

#include "sysfs.h"



static void btrfs_release_super_kobj(struct kobject *kobj);

static struct kobj_type btrfs_ktype = {

	.sysfs_ops	= &kobj_sysfs_ops,

	.release	= btrfs_release_super_kobj,

};

static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);



static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)

static u64 get_features(struct btrfs_fs_info *fs_info,

			enum btrfs_feature_set set)

{

	if (kobj->ktype != &btrfs_ktype)

		return NULL;

	return container_of(kobj, struct btrfs_fs_info, super_kobj);

	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 btrfs_release_super_kobj(struct kobject *kobj)

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);

	complete(&fs_info->kobj_unregister);

	if (fs_info) {

		struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);

		u64 features = get_features(fs_info, fa->feature_set);

		if (features & fa->feature_bit)

			val = 1;

	}



static ssize_t btrfs_feature_attr_show(struct kobject *kobj,

				       struct kobj_attribute *a, char *buf)

	return snprintf(buf, PAGE_SIZE, "%d\n", val);

}



static umode_t btrfs_feature_visible(struct kobject *kobj,

				     struct attribute *attr, int unused)

{

	return snprintf(buf, PAGE_SIZE, "0\n");

	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 (!(features & fa->feature_bit))

			mode = 0;

	}



	return mode;

}



BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF);
@@ -78,11 +102,27 @@ static struct attribute *btrfs_supported_feature_attrs[] = { 


static const struct attribute_group btrfs_feature_attr_group = {

	.name = "features",

	.is_visible = btrfs_feature_visible,

	.attrs = btrfs_supported_feature_attrs,

};



/* /sys/fs/btrfs/ entry */

static struct kset *btrfs_kset;

static void btrfs_release_super_kobj(struct kobject *kobj)

{

	struct btrfs_fs_info *fs_info = to_fs_info(kobj);

	complete(&fs_info->kobj_unregister);

}



static struct kobj_type btrfs_ktype = {

	.sysfs_ops	= &kobj_sysfs_ops,

	.release	= btrfs_release_super_kobj,

};



static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)

{

	if (kobj->ktype != &btrfs_ktype)

		return NULL;

	return container_of(kobj, struct btrfs_fs_info, super_kobj);

}



void btrfs_sysfs_remove_one(struct btrfs_fs_info *fs_info)

{
@@ -91,13 +131,22 @@ void btrfs_sysfs_remove_one(struct btrfs_fs_info *fs_info) 
	wait_for_completion(&fs_info->kobj_unregister);

}



/* /sys/fs/btrfs/ entry */

static struct kset *btrfs_kset;



int btrfs_sysfs_add_one(struct btrfs_fs_info *fs_info)

{

	int error;



	init_completion(&fs_info->kobj_unregister);

	fs_info->super_kobj.kset = btrfs_kset;

	error = kobject_init_and_add(&fs_info->super_kobj, &btrfs_ktype, NULL,

				     "%pU", fs_info->fsid);



	error = sysfs_create_group(&fs_info->super_kobj,

				   &btrfs_feature_attr_group);

	if (error)

		btrfs_sysfs_remove_one(fs_info);

	return error;

}