nilfs2: add /sys/fs/nilfs2/<device>/mounted_snapshots/<snapshot> group

This patch adds creation of <snapshot> group for every mounted
snapshot in /sys/fs/nilfs2/<device>/mounted_snapshots group.

The group contains details about mounted snapshot:
(1) inodes_count - show number of inodes for snapshot.
(2) blocks_count - show number of blocks for snapshot.

Signed-off-by: Vyacheslav 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Vyacheslav Dubeyko 2014-08-08 14:20:52 -07:00 committed by Linus Torvalds
parent a2ecb791a9
commit a5a7332a29
4 changed files with 163 additions and 0 deletions

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@ -248,3 +248,22 @@ Contact: "Vyacheslav Dubeyko" <slava@dubeyko.com>
Description:
Describe content of /sys/fs/nilfs2/<device>/mounted_snapshots
group.
What: /sys/fs/nilfs2/<device>/mounted_snapshots/<id>/inodes_count
Date: April 2014
Contact: "Vyacheslav Dubeyko" <slava@dubeyko.com>
Description:
Show number of inodes for snapshot.
What: /sys/fs/nilfs2/<device>/mounted_snapshots/<id>/blocks_count
Date: April 2014
Contact: "Vyacheslav Dubeyko" <slava@dubeyko.com>
Description:
Show number of blocks for snapshot.
What: /sys/fs/nilfs2/<device>/mounted_snapshots/<id>/README
Date: April 2014
Contact: "Vyacheslav Dubeyko" <slava@dubeyko.com>
Description:
Describe attributes of /sys/fs/nilfs2/<device>/mounted_snapshots/<id>
group.

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@ -111,6 +111,124 @@ void nilfs_sysfs_delete_##name##_group(struct the_nilfs *nilfs) \
kobject_del(&nilfs->ns_##parent_name##_subgroups->sg_##name##_kobj); \
}
/************************************************************************
* NILFS snapshot attrs *
************************************************************************/
static ssize_t
nilfs_snapshot_inodes_count_show(struct nilfs_snapshot_attr *attr,
struct nilfs_root *root, char *buf)
{
return snprintf(buf, PAGE_SIZE, "%llu\n",
(unsigned long long)atomic64_read(&root->inodes_count));
}
static ssize_t
nilfs_snapshot_blocks_count_show(struct nilfs_snapshot_attr *attr,
struct nilfs_root *root, char *buf)
{
return snprintf(buf, PAGE_SIZE, "%llu\n",
(unsigned long long)atomic64_read(&root->blocks_count));
}
static const char snapshot_readme_str[] =
"The group contains details about mounted snapshot.\n\n"
"(1) inodes_count\n\tshow number of inodes for snapshot.\n\n"
"(2) blocks_count\n\tshow number of blocks for snapshot.\n\n";
static ssize_t
nilfs_snapshot_README_show(struct nilfs_snapshot_attr *attr,
struct nilfs_root *root, char *buf)
{
return snprintf(buf, PAGE_SIZE, snapshot_readme_str);
}
NILFS_SNAPSHOT_RO_ATTR(inodes_count);
NILFS_SNAPSHOT_RO_ATTR(blocks_count);
NILFS_SNAPSHOT_RO_ATTR(README);
static struct attribute *nilfs_snapshot_attrs[] = {
NILFS_SNAPSHOT_ATTR_LIST(inodes_count),
NILFS_SNAPSHOT_ATTR_LIST(blocks_count),
NILFS_SNAPSHOT_ATTR_LIST(README),
NULL,
};
static ssize_t nilfs_snapshot_attr_show(struct kobject *kobj,
struct attribute *attr, char *buf)
{
struct nilfs_root *root =
container_of(kobj, struct nilfs_root, snapshot_kobj);
struct nilfs_snapshot_attr *a =
container_of(attr, struct nilfs_snapshot_attr, attr);
return a->show ? a->show(a, root, buf) : 0;
}
static ssize_t nilfs_snapshot_attr_store(struct kobject *kobj,
struct attribute *attr,
const char *buf, size_t len)
{
struct nilfs_root *root =
container_of(kobj, struct nilfs_root, snapshot_kobj);
struct nilfs_snapshot_attr *a =
container_of(attr, struct nilfs_snapshot_attr, attr);
return a->store ? a->store(a, root, buf, len) : 0;
}
static void nilfs_snapshot_attr_release(struct kobject *kobj)
{
struct nilfs_root *root = container_of(kobj, struct nilfs_root,
snapshot_kobj);
complete(&root->snapshot_kobj_unregister);
}
static const struct sysfs_ops nilfs_snapshot_attr_ops = {
.show = nilfs_snapshot_attr_show,
.store = nilfs_snapshot_attr_store,
};
static struct kobj_type nilfs_snapshot_ktype = {
.default_attrs = nilfs_snapshot_attrs,
.sysfs_ops = &nilfs_snapshot_attr_ops,
.release = nilfs_snapshot_attr_release,
};
int nilfs_sysfs_create_snapshot_group(struct nilfs_root *root)
{
struct the_nilfs *nilfs;
struct kobject *parent;
int err;
nilfs = root->nilfs;
parent = &nilfs->ns_dev_subgroups->sg_mounted_snapshots_kobj;
root->snapshot_kobj.kset = nilfs_kset;
init_completion(&root->snapshot_kobj_unregister);
if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
err = kobject_init_and_add(&root->snapshot_kobj,
&nilfs_snapshot_ktype,
&nilfs->ns_dev_kobj,
"current_checkpoint");
} else {
err = kobject_init_and_add(&root->snapshot_kobj,
&nilfs_snapshot_ktype,
parent,
"%llu", root->cno);
}
if (err)
return err;
return 0;
}
void nilfs_sysfs_delete_snapshot_group(struct nilfs_root *root)
{
kobject_del(&root->snapshot_kobj);
}
/************************************************************************
* NILFS mounted snapshots attrs *
************************************************************************/

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@ -86,6 +86,17 @@ NILFS_DEV_ATTR_STRUCT(checkpoints);
NILFS_DEV_ATTR_STRUCT(superblock);
NILFS_DEV_ATTR_STRUCT(segctor);
#define NILFS_CP_ATTR_STRUCT(name) \
struct nilfs_##name##_attr { \
struct attribute attr; \
ssize_t (*show)(struct nilfs_##name##_attr *, struct nilfs_root *, \
char *); \
ssize_t (*store)(struct nilfs_##name##_attr *, struct nilfs_root *, \
const char *, size_t); \
};
NILFS_CP_ATTR_STRUCT(snapshot);
#define NILFS_ATTR(type, name, mode, show, store) \
static struct nilfs_##type##_attr nilfs_##type##_attr_##name = \
__ATTR(name, mode, show, store)
@ -126,6 +137,13 @@ NILFS_DEV_ATTR_STRUCT(segctor);
#define NILFS_CHECKPOINTS_RW_ATTR(name) \
NILFS_RW_ATTR(checkpoints, name)
#define NILFS_SNAPSHOT_INFO_ATTR(name) \
NILFS_INFO_ATTR(snapshot, name)
#define NILFS_SNAPSHOT_RO_ATTR(name) \
NILFS_RO_ATTR(snapshot, name)
#define NILFS_SNAPSHOT_RW_ATTR(name) \
NILFS_RW_ATTR(snapshot, name)
#define NILFS_SUPERBLOCK_RO_ATTR(name) \
NILFS_RO_ATTR(superblock, name)
#define NILFS_SUPERBLOCK_RW_ATTR(name) \
@ -148,6 +166,8 @@ NILFS_DEV_ATTR_STRUCT(segctor);
(&nilfs_mounted_snapshots_attr_##name.attr)
#define NILFS_CHECKPOINTS_ATTR_LIST(name) \
(&nilfs_checkpoints_attr_##name.attr)
#define NILFS_SNAPSHOT_ATTR_LIST(name) \
(&nilfs_snapshot_attr_##name.attr)
#define NILFS_SUPERBLOCK_ATTR_LIST(name) \
(&nilfs_superblock_attr_##name.attr)
#define NILFS_SEGCTOR_ATTR_LIST(name) \

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@ -243,6 +243,8 @@ THE_NILFS_FNS(SB_DIRTY, sb_dirty)
* @ifile: inode file
* @inodes_count: number of inodes
* @blocks_count: number of blocks
* @snapshot_kobj: /sys/fs/<nilfs>/<device>/mounted_snapshots/<snapshot>
* @snapshot_kobj_unregister: completion state for kernel object
*/
struct nilfs_root {
__u64 cno;
@ -254,6 +256,10 @@ struct nilfs_root {
atomic64_t inodes_count;
atomic64_t blocks_count;
/* /sys/fs/<nilfs>/<device>/mounted_snapshots/<snapshot> */
struct kobject snapshot_kobj;
struct completion snapshot_kobj_unregister;
};
/* Special checkpoint number */