Commit caa05d49 authored by Vyacheslav Dubeyko's avatar Vyacheslav Dubeyko Committed by Linus Torvalds
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nilfs2: add /sys/fs/nilfs2/<device>/superblock group 



This patch adds creation of /sys/fs/nilfs2/<device>/superblock
group.

The superblock group contains attributes that describe
superblock's details:
(1) sb_write_time - show previous write time of super block in
human-readable format.
(2) sb_write_time_secs - show previous write time of super block
in seconds.
(3) sb_write_count - show write count of super block.
(4) sb_update_frequency - show/set interval of periodical update
of superblock (in seconds). You can set preferable frequency of
superblock update by command:

echo <value> > /sys/fs/nilfs2/<device>/superblock/sb_update_frequency

Signed-off-by: default avatarVyacheslav Dubeyko <Vyacheslav.Dubeyko@hgst.com>
Cc: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Michael L. Semon <mlsemon35@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent da7141fb

Documentation/ABI/testing/sysfs-fs-nilfs2

+33 −0
Original line number Diff line number Diff line
@@ -56,3 +56,36 @@ Date: April 2014 
Contact:	"Vyacheslav Dubeyko" <slava@dubeyko.com>

Description:

		Describe attributes of /sys/fs/nilfs2/<device> group.



What:		/sys/fs/nilfs2/<device>/superblock/sb_write_time

Date:		April 2014

Contact:	"Vyacheslav Dubeyko" <slava@dubeyko.com>

Description:

		Show last write time of super block in human-readable

		format.



What:		/sys/fs/nilfs2/<device>/superblock/sb_write_time_secs

Date:		April 2014

Contact:	"Vyacheslav Dubeyko" <slava@dubeyko.com>

Description:

		Show last write time of super block in seconds.



What:		/sys/fs/nilfs2/<device>/superblock/sb_write_count

Date:		April 2014

Contact:	"Vyacheslav Dubeyko" <slava@dubeyko.com>

Description:

		Show current write count of super block.



What:		/sys/fs/nilfs2/<device>/superblock/sb_update_frequency

Date:		April 2014

Contact:	"Vyacheslav Dubeyko" <slava@dubeyko.com>

Description:

		Show/Set interval of periodical update of superblock

		(in seconds).



What:		/sys/fs/nilfs2/<device>/superblock/README

Date:		April 2014

Contact:	"Vyacheslav Dubeyko" <slava@dubeyko.com>

Description:

		Describe attributes of /sys/fs/nilfs2/<device>/superblock

		group.

fs/nilfs2/sysfs.c

+217 −1
Original line number Diff line number Diff line
@@ -41,6 +41,202 @@ static struct kset *nilfs_kset; 
		count; \

})



#define NILFS_DEV_INT_GROUP_OPS(name, parent_name) \

static ssize_t nilfs_##name##_attr_show(struct kobject *kobj, \

					struct attribute *attr, char *buf) \

{ \

	struct the_nilfs *nilfs = container_of(kobj->parent, \

						struct the_nilfs, \

						ns_##parent_name##_kobj); \

	struct nilfs_##name##_attr *a = container_of(attr, \

						struct nilfs_##name##_attr, \

						attr); \

	return a->show ? a->show(a, nilfs, buf) : 0; \

} \

static ssize_t nilfs_##name##_attr_store(struct kobject *kobj, \

					 struct attribute *attr, \

					 const char *buf, size_t len) \

{ \

	struct the_nilfs *nilfs = container_of(kobj->parent, \

						struct the_nilfs, \

						ns_##parent_name##_kobj); \

	struct nilfs_##name##_attr *a = container_of(attr, \

						struct nilfs_##name##_attr, \

						attr); \

	return a->store ? a->store(a, nilfs, buf, len) : 0; \

} \

static const struct sysfs_ops nilfs_##name##_attr_ops = { \

	.show	= nilfs_##name##_attr_show, \

	.store	= nilfs_##name##_attr_store, \

};



#define NILFS_DEV_INT_GROUP_TYPE(name, parent_name) \

static void nilfs_##name##_attr_release(struct kobject *kobj) \

{ \

	struct nilfs_sysfs_##parent_name##_subgroups *subgroups; \

	struct the_nilfs *nilfs = container_of(kobj->parent, \

						struct the_nilfs, \

						ns_##parent_name##_kobj); \

	subgroups = nilfs->ns_##parent_name##_subgroups; \

	complete(&subgroups->sg_##name##_kobj_unregister); \

} \

static struct kobj_type nilfs_##name##_ktype = { \

	.default_attrs	= nilfs_##name##_attrs, \

	.sysfs_ops	= &nilfs_##name##_attr_ops, \

	.release	= nilfs_##name##_attr_release, \

};



#define NILFS_DEV_INT_GROUP_FNS(name, parent_name) \

int nilfs_sysfs_create_##name##_group(struct the_nilfs *nilfs) \

{ \

	struct kobject *parent; \

	struct kobject *kobj; \

	struct completion *kobj_unregister; \

	struct nilfs_sysfs_##parent_name##_subgroups *subgroups; \

	int err; \

	subgroups = nilfs->ns_##parent_name##_subgroups; \

	kobj = &subgroups->sg_##name##_kobj; \

	kobj_unregister = &subgroups->sg_##name##_kobj_unregister; \

	parent = &nilfs->ns_##parent_name##_kobj; \

	kobj->kset = nilfs_kset; \

	init_completion(kobj_unregister); \

	err = kobject_init_and_add(kobj, &nilfs_##name##_ktype, parent, \

				    #name); \

	if (err) \

		return err; \

	return 0; \

} \

void nilfs_sysfs_delete_##name##_group(struct the_nilfs *nilfs) \

{ \

	kobject_del(&nilfs->ns_##parent_name##_subgroups->sg_##name##_kobj); \

}



/************************************************************************

 *                        NILFS superblock attrs                        *

 ************************************************************************/



static ssize_t

nilfs_superblock_sb_write_time_show(struct nilfs_superblock_attr *attr,

				     struct the_nilfs *nilfs,

				     char *buf)

{

	time_t sbwtime;



	down_read(&nilfs->ns_sem);

	sbwtime = nilfs->ns_sbwtime;

	up_read(&nilfs->ns_sem);



	return NILFS_SHOW_TIME(sbwtime, buf);

}



static ssize_t

nilfs_superblock_sb_write_time_secs_show(struct nilfs_superblock_attr *attr,

					 struct the_nilfs *nilfs,

					 char *buf)

{

	time_t sbwtime;



	down_read(&nilfs->ns_sem);

	sbwtime = nilfs->ns_sbwtime;

	up_read(&nilfs->ns_sem);



	return snprintf(buf, PAGE_SIZE, "%llu\n", (unsigned long long)sbwtime);

}



static ssize_t

nilfs_superblock_sb_write_count_show(struct nilfs_superblock_attr *attr,

				      struct the_nilfs *nilfs,

				      char *buf)

{

	unsigned sbwcount;



	down_read(&nilfs->ns_sem);

	sbwcount = nilfs->ns_sbwcount;

	up_read(&nilfs->ns_sem);



	return snprintf(buf, PAGE_SIZE, "%u\n", sbwcount);

}



static ssize_t

nilfs_superblock_sb_update_frequency_show(struct nilfs_superblock_attr *attr,

					    struct the_nilfs *nilfs,

					    char *buf)

{

	unsigned sb_update_freq;



	down_read(&nilfs->ns_sem);

	sb_update_freq = nilfs->ns_sb_update_freq;

	up_read(&nilfs->ns_sem);



	return snprintf(buf, PAGE_SIZE, "%u\n", sb_update_freq);

}



static ssize_t

nilfs_superblock_sb_update_frequency_store(struct nilfs_superblock_attr *attr,

					    struct the_nilfs *nilfs,

					    const char *buf, size_t count)

{

	unsigned val;

	int err;



	err = kstrtouint(skip_spaces(buf), 0, &val);

	if (err) {

		printk(KERN_ERR "NILFS: unable to convert string: err=%d\n",

			err);

		return err;

	}



	if (val < NILFS_SB_FREQ) {

		val = NILFS_SB_FREQ;

		printk(KERN_WARNING "NILFS: superblock update frequency cannot be lesser than 10 seconds\n");

	}



	down_write(&nilfs->ns_sem);

	nilfs->ns_sb_update_freq = val;

	up_write(&nilfs->ns_sem);



	return count;

}



static const char sb_readme_str[] =

	"The superblock group contains attributes that describe\n"

	"superblock's details.\n\n"

	"(1) sb_write_time\n\tshow previous write time of super block "

	"in human-readable format.\n\n"

	"(2) sb_write_time_secs\n\tshow previous write time of super block "

	"in seconds.\n\n"

	"(3) sb_write_count\n\tshow write count of super block.\n\n"

	"(4) sb_update_frequency\n"

	"\tshow/set interval of periodical update of superblock (in seconds).\n\n"

	"\tYou can set preferable frequency of superblock update by command:\n\n"

	"\t'echo <val> > /sys/fs/<nilfs>/<dev>/superblock/sb_update_frequency'\n";



static ssize_t

nilfs_superblock_README_show(struct nilfs_superblock_attr *attr,

				struct the_nilfs *nilfs, char *buf)

{

	return snprintf(buf, PAGE_SIZE, sb_readme_str);

}



NILFS_SUPERBLOCK_RO_ATTR(sb_write_time);

NILFS_SUPERBLOCK_RO_ATTR(sb_write_time_secs);

NILFS_SUPERBLOCK_RO_ATTR(sb_write_count);

NILFS_SUPERBLOCK_RW_ATTR(sb_update_frequency);

NILFS_SUPERBLOCK_RO_ATTR(README);



static struct attribute *nilfs_superblock_attrs[] = {

	NILFS_SUPERBLOCK_ATTR_LIST(sb_write_time),

	NILFS_SUPERBLOCK_ATTR_LIST(sb_write_time_secs),

	NILFS_SUPERBLOCK_ATTR_LIST(sb_write_count),

	NILFS_SUPERBLOCK_ATTR_LIST(sb_update_frequency),

	NILFS_SUPERBLOCK_ATTR_LIST(README),

	NULL,

};



NILFS_DEV_INT_GROUP_OPS(superblock, dev);

NILFS_DEV_INT_GROUP_TYPE(superblock, dev);

NILFS_DEV_INT_GROUP_FNS(superblock, dev);



/************************************************************************

 *                        NILFS device attrs                            *

 ************************************************************************/
@@ -189,24 +385,44 @@ static struct kobj_type nilfs_dev_ktype = { 
int nilfs_sysfs_create_device_group(struct super_block *sb)

{

	struct the_nilfs *nilfs = sb->s_fs_info;

	size_t devgrp_size = sizeof(struct nilfs_sysfs_dev_subgroups);

	int err;



	nilfs->ns_dev_subgroups = kzalloc(devgrp_size, GFP_KERNEL);

	if (unlikely(!nilfs->ns_dev_subgroups)) {

		err = -ENOMEM;

		printk(KERN_ERR "NILFS: unable to allocate memory for device group\n");

		goto failed_create_device_group;

	}



	nilfs->ns_dev_kobj.kset = nilfs_kset;

	init_completion(&nilfs->ns_dev_kobj_unregister);

	err = kobject_init_and_add(&nilfs->ns_dev_kobj, &nilfs_dev_ktype, NULL,

				    "%s", sb->s_id);

	if (err)

		goto failed_create_device_group;

		goto free_dev_subgroups;



	err = nilfs_sysfs_create_superblock_group(nilfs);

	if (err)

		goto cleanup_dev_kobject;



	return 0;



cleanup_dev_kobject:

	kobject_del(&nilfs->ns_dev_kobj);



free_dev_subgroups:

	kfree(nilfs->ns_dev_subgroups);



failed_create_device_group:

	return err;

}



void nilfs_sysfs_delete_device_group(struct the_nilfs *nilfs)

{

	nilfs_sysfs_delete_superblock_group(nilfs);

	kobject_del(&nilfs->ns_dev_kobj);

	kfree(nilfs->ns_dev_subgroups);

}



/************************************************************************

fs/nilfs2/sysfs.h

+19 −0
Original line number Diff line number Diff line
@@ -24,6 +24,17 @@ 


#define NILFS_ROOT_GROUP_NAME	"nilfs2"



/*

 * struct nilfs_sysfs_dev_subgroups - device subgroup kernel objects

 * @sg_superblock_kobj: /sys/fs/<nilfs>/<device>/superblock

 * @sg_superblock_kobj_unregister: completion state

 */

struct nilfs_sysfs_dev_subgroups {

	/* /sys/fs/<nilfs>/<device>/superblock */

	struct kobject sg_superblock_kobj;

	struct completion sg_superblock_kobj_unregister;

};



#define NILFS_COMMON_ATTR_STRUCT(name) \

struct nilfs_##name##_attr { \

	struct attribute attr; \
@@ -45,6 +56,7 @@ struct nilfs_##name##_attr { \ 
};



NILFS_DEV_ATTR_STRUCT(dev);

NILFS_DEV_ATTR_STRUCT(superblock);



#define NILFS_ATTR(type, name, mode, show, store) \

	static struct nilfs_##type##_attr nilfs_##type##_attr_##name = \
@@ -73,9 +85,16 @@ NILFS_DEV_ATTR_STRUCT(dev); 
#define NILFS_DEV_RW_ATTR(name) \

	NILFS_RW_ATTR(dev, name)



#define NILFS_SUPERBLOCK_RO_ATTR(name) \

	NILFS_RO_ATTR(superblock, name)

#define NILFS_SUPERBLOCK_RW_ATTR(name) \

	NILFS_RW_ATTR(superblock, name)



#define NILFS_FEATURE_ATTR_LIST(name) \

	(&nilfs_feature_attr_##name.attr)

#define NILFS_DEV_ATTR_LIST(name) \

	(&nilfs_dev_attr_##name.attr)

#define NILFS_SUPERBLOCK_ATTR_LIST(name) \

	(&nilfs_superblock_attr_##name.attr)



#endif /* _NILFS_SYSFS_H */

fs/nilfs2/the_nilfs.c

+1 −0
Original line number Diff line number Diff line
@@ -85,6 +85,7 @@ struct the_nilfs *alloc_nilfs(struct block_device *bdev) 
	nilfs->ns_cptree = RB_ROOT;

	spin_lock_init(&nilfs->ns_cptree_lock);

	init_rwsem(&nilfs->ns_segctor_sem);

	nilfs->ns_sb_update_freq = NILFS_SB_FREQ;



	return nilfs;

}

fs/nilfs2/the_nilfs.h

+7 −1
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ 
#include <linux/slab.h>



struct nilfs_sc_info;

struct nilfs_sysfs_dev_subgroups;



/* the_nilfs struct */

enum {
@@ -54,6 +55,7 @@ enum { 
 * @ns_sbwcount: write count of super block

 * @ns_sbsize: size of valid data in super block

 * @ns_mount_state: file system state

 * @ns_sb_update_freq: interval of periodical update of superblocks (in seconds)

 * @ns_seg_seq: segment sequence counter

 * @ns_segnum: index number of the latest full segment.

 * @ns_nextnum: index number of the full segment index to be used next
@@ -97,6 +99,7 @@ enum { 
 * @ns_crc_seed: seed value of CRC32 calculation

 * @ns_dev_kobj: /sys/fs/<nilfs>/<device>

 * @ns_dev_kobj_unregister: completion state

 * @ns_dev_subgroups: <device> subgroups pointer

 */

struct the_nilfs {

	unsigned long		ns_flags;
@@ -116,6 +119,7 @@ struct the_nilfs { 
	unsigned		ns_sbwcount;

	unsigned		ns_sbsize;

	unsigned		ns_mount_state;

	unsigned		ns_sb_update_freq;



	/*

	 * Following fields are dedicated to a writable FS-instance.
@@ -194,6 +198,7 @@ struct the_nilfs { 
	/* /sys/fs/<nilfs>/<device> */

	struct kobject ns_dev_kobj;

	struct completion ns_dev_kobj_unregister;

	struct nilfs_sysfs_dev_subgroups *ns_dev_subgroups;

};



#define THE_NILFS_FNS(bit, name)					\
@@ -260,7 +265,8 @@ struct nilfs_root { 
static inline int nilfs_sb_need_update(struct the_nilfs *nilfs)

{

	u64 t = get_seconds();

	return t < nilfs->ns_sbwtime || t > nilfs->ns_sbwtime + NILFS_SB_FREQ;

	return t < nilfs->ns_sbwtime ||

		t > nilfs->ns_sbwtime + nilfs->ns_sb_update_freq;

}



static inline int nilfs_sb_will_flip(struct the_nilfs *nilfs)

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