[Ocfs2-devel] [PATCH 1/5] ocfs2: Provisions for sysfs entries

[Goldwyn Rodrigues <rgoldwyn@suse.de>]

From: Goldwyn Rodrigues <rgoldwyn@suse.com>

This adds /sys/fs/ocfs2/<s_id> to the sys filesystem. This
is done by adding the kobj into the ocfs2_super. All other
files are added in this directory.

Introduce ocfs2_sb_attr which encompasses the store() and show() functions.
Move all the important data structures with respect to filechecks
to ocfs2_super.

More superblock information should move in here.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
---
 fs/ocfs2/Makefile |  3 +-
 fs/ocfs2/ocfs2.h  |  4 +++
 fs/ocfs2/super.c  |  7 +++--
 fs/ocfs2/sysfs.c  | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/ocfs2/sysfs.h  |  9 ++++++
 5 files changed, 111 insertions(+), 4 deletions(-)
 create mode 100644 fs/ocfs2/sysfs.c
 create mode 100644 fs/ocfs2/sysfs.h

diff --git a/fs/ocfs2/Makefile b/fs/ocfs2/Makefile
index e27e652..716ed45 100644
--- a/fs/ocfs2/Makefile
+++ b/fs/ocfs2/Makefile
@@ -41,7 +41,8 @@ ocfs2-objs := \
 	quota_local.o		\
 	quota_global.o		\
 	xattr.o			\
-	acl.o	\
+	acl.o			\
+	sysfs.o			\
 	filecheck.o
 
 ocfs2_stackglue-objs := stackglue.o
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index e63af7d..8e66cdf 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -37,6 +37,7 @@
 #include <linux/mutex.h>
 #include <linux/lockdep.h>
 #include <linux/jbd2.h>
+#include <linux/kobject.h>
 
 /* For union ocfs2_dlm_lksb */
 #include "stackglue.h"
@@ -472,6 +473,9 @@ struct ocfs2_super
 	 * workqueue and schedule on our own.
 	 */
 	struct workqueue_struct *ocfs2_wq;
+
+	struct kobject kobj;
+	struct completion kobj_unregister;
 };
 
 #define OCFS2_SB(sb)	    ((struct ocfs2_super *)(sb)->s_fs_info)
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index d7cae33..96b7a9f 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -75,6 +75,7 @@
 
 #include "buffer_head_io.h"
 #include "filecheck.h"
+#include "sysfs.h"
 
 static struct kmem_cache *ocfs2_inode_cachep;
 struct kmem_cache *ocfs2_dquot_cachep;
@@ -1200,8 +1201,8 @@ static int ocfs2_fill_super(struct super_block *sb, void *data, int silent)
 	/* Start this when the mount is almost sure of being successful */
 	ocfs2_orphan_scan_start(osb);
 
-	/* Create filecheck sysfile /sys/fs/ocfs2/<devname>/filecheck */
-	ocfs2_filecheck_create_sysfs(sb);
+	/* Create sysfs entries */
+	ocfs2_sysfs_sb_init(sb);
 
 	return status;
 
@@ -1651,9 +1652,9 @@ static void ocfs2_put_super(struct super_block *sb)
 {
 	trace_ocfs2_put_super(sb);
 
+	ocfs2_sysfs_sb_exit(sb);
 	ocfs2_sync_blockdev(sb);
 	ocfs2_dismount_volume(sb, 0);
-	ocfs2_filecheck_remove_sysfs(sb);
 }
 
 static int ocfs2_statfs(struct dentry *dentry, struct kstatfs *buf)
diff --git a/fs/ocfs2/sysfs.c b/fs/ocfs2/sysfs.c
new file mode 100644
index 0000000..f0b7435
--- /dev/null
+++ b/fs/ocfs2/sysfs.c
@@ -0,0 +1,92 @@
+#include "ocfs2.h"
+#include "sysfs.h"
+
+struct ocfs2_sb_attr {
+	struct attribute attr;
+	ssize_t (*show)(struct ocfs2_super *, struct ocfs2_sb_attr *,
+			char *buf);
+	ssize_t (*store)(struct ocfs2_super *, struct ocfs2_sb_attr *,
+			const char *buf, size_t count);
+};
+
+#define OCFS2_SB_ATTR(_name, _mode) \
+struct ocfs2_sb_attr sb_attr_##_name = __ATTR(name, _mode, _show, _store)
+
+#define OCFS2_SB_ATTR_RO(_name) \
+struct ocfs2_sb_attr sb_attr_##_name = __ATTR_RO(_name)
+
+static ssize_t ocfs2_sb_attr_show(struct kobject *kobj,
+		struct attribute *attr, char *buf)
+{
+	struct ocfs2_sb_attr *oa =
+		container_of(attr, struct ocfs2_sb_attr, attr);
+	struct ocfs2_super *osb = container_of(kobj, struct ocfs2_super, kobj);
+	if (!oa->show)
+		return -EIO;
+
+	return oa->show(osb, oa, buf);
+}
+
+static ssize_t ocfs2_sb_attr_store(struct kobject *kobj,
+		struct attribute *attr, const char *buf, size_t count)
+{
+	struct ocfs2_sb_attr *oa =
+		container_of(attr, struct ocfs2_sb_attr, attr);
+	struct ocfs2_super *osb = container_of(kobj, struct ocfs2_super, kobj);
+	if (!oa->show)
+		return -EIO;
+
+	return oa->store(osb, oa, buf, count);
+}
+
+static ssize_t slot_num_show(struct ocfs2_super *osb,
+			     struct ocfs2_sb_attr *attr,
+	  		     char *buf)
+{
+	return sprintf(buf, "%d\n", osb->slot_num);
+}
+
+static void sb_release(struct kobject *kobj)
+{
+	struct ocfs2_super *osb = container_of(kobj, struct ocfs2_super, kobj);
+	complete(&osb->kobj_unregister);
+}
+
+static const struct sysfs_ops ocfs2_sb_sysfs_ops = {
+	.show = ocfs2_sb_attr_show,
+	.store = ocfs2_sb_attr_store,
+};
+
+static OCFS2_SB_ATTR_RO(slot_num);
+static struct attribute *ocfs2_sb_attrs[] = {
+	&sb_attr_slot_num.attr,
+	NULL
+};
+
+static struct kobj_type ocfs2_sb_ktype = {
+	.sysfs_ops 	= &ocfs2_sb_sysfs_ops,
+	.default_attrs 	= ocfs2_sb_attrs,
+	.release	= sb_release,
+};
+
+
+int ocfs2_sysfs_sb_init(struct super_block *sb)
+{
+	int err;
+	struct ocfs2_super *osb = OCFS2_SB(sb);
+	init_completion(&osb->kobj_unregister);
+	osb->kobj.kset = ocfs2_kset;
+	err = kobject_init_and_add(&osb->kobj, &ocfs2_sb_ktype, NULL, "%s", sb->s_id);
+	return err;
+
+}
+
+void ocfs2_sysfs_sb_exit(struct super_block *sb)
+{
+	struct ocfs2_super *osb = OCFS2_SB(sb);
+	kobject_del(&osb->kobj);
+	kobject_put(&osb->kobj);
+	wait_for_completion(&osb->kobj_unregister);
+}
+
+
diff --git a/fs/ocfs2/sysfs.h b/fs/ocfs2/sysfs.h
new file mode 100644
index 0000000..d929ac1
--- /dev/null
+++ b/fs/ocfs2/sysfs.h
@@ -0,0 +1,9 @@
+
+
+#ifndef _SYS_H
+#define _SYS_H
+
+int ocfs2_sysfs_sb_init(struct super_block *sb);
+void ocfs2_sysfs_sb_exit(struct super_block *sb);
+
+#endif
-- 
2.6.6