sysfs: Basic support for multiple super blocks
Add all of the necessary bioler plate to support
multiple superblocks in sysfs.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
index 7761378..db0b1f2 100644
--- a/fs/sysfs/mount.c
+++ b/fs/sysfs/mount.c
@@ -72,16 +72,70 @@
return 0;
}
+static int sysfs_test_super(struct super_block *sb, void *data)
+{
+ struct sysfs_super_info *sb_info = sysfs_info(sb);
+ struct sysfs_super_info *info = data;
+ int found = 1;
+ return found;
+}
+
+static int sysfs_set_super(struct super_block *sb, void *data)
+{
+ int error;
+ error = set_anon_super(sb, data);
+ if (!error)
+ sb->s_fs_info = data;
+ return error;
+}
+
static int sysfs_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
- return get_sb_single(fs_type, flags, data, sysfs_fill_super, mnt);
+ struct sysfs_super_info *info;
+ struct super_block *sb;
+ int error;
+
+ error = -ENOMEM;
+ info = kzalloc(sizeof(*info), GFP_KERNEL);
+ if (!info)
+ goto out;
+ sb = sget(fs_type, sysfs_test_super, sysfs_set_super, info);
+ if (IS_ERR(sb) || sb->s_fs_info != info)
+ kfree(info);
+ if (IS_ERR(sb)) {
+ kfree(info);
+ error = PTR_ERR(sb);
+ goto out;
+ }
+ if (!sb->s_root) {
+ sb->s_flags = flags;
+ error = sysfs_fill_super(sb, data, flags & MS_SILENT ? 1 : 0);
+ if (error) {
+ deactivate_locked_super(sb);
+ goto out;
+ }
+ sb->s_flags |= MS_ACTIVE;
+ }
+
+ simple_set_mnt(mnt, sb);
+ error = 0;
+out:
+ return error;
+}
+
+static void sysfs_kill_sb(struct super_block *sb)
+{
+ struct sysfs_super_info *info = sysfs_info(sb);
+
+ kill_anon_super(sb);
+ kfree(info);
}
static struct file_system_type sysfs_fs_type = {
.name = "sysfs",
.get_sb = sysfs_get_sb,
- .kill_sb = kill_anon_super,
+ .kill_sb = sysfs_kill_sb,
};
int __init sysfs_init(void)
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index 30f5a44..030a39d 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -114,6 +114,9 @@
/*
* mount.c
*/
+struct sysfs_super_info {
+};
+#define sysfs_info(SB) ((struct sysfs_super_info *)(SB->s_fs_info))
extern struct sysfs_dirent sysfs_root;
extern struct kmem_cache *sysfs_dir_cachep;