nilfs2: simplify life cycle management of nilfs object

This stops pre-allocating nilfs object in nilfs_get_sb routine, and
stops managing its life cycle by reference counting.

nilfs_find_or_create_nilfs() function, nilfs->ns_mount_mutex,
nilfs_objects list, and the reference counter will be removed through
the simplification.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index 2ee6843c2e87..338858fc907c 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -117,7 +117,7 @@ static int nilfs_ioctl_change_cpmode(struct inode *inode, struct file *filp,
         if (copy_from_user(&cpmode, argp, sizeof(cpmode)))
                 goto out;
 
-        mutex_lock(&nilfs->ns_mount_mutex);
+        down_read(&inode->i_sb->s_umount);
 
         nilfs_transaction_begin(inode->i_sb, &ti, 0);
         ret = nilfs_cpfile_change_cpmode(
@@ -127,7 +127,7 @@ static int nilfs_ioctl_change_cpmode(struct inode *inode, struct file *filp,
         else
                 nilfs_transaction_commit(inode->i_sb); /* never fails */
 
-        mutex_unlock(&nilfs->ns_mount_mutex);
+        up_read(&inode->i_sb->s_umount);
 out:
         mnt_drop_write(filp->f_path.mnt);
         return ret;