Commit 781716cd authored by Al Viro's avatar Al Viro
Browse files

hypfs: don't pin dentries twice 



hypfs dentries end up with refcount 2 when they are not busy.
Refcount 1 is enough to keep them pinned, and going that way
allows to simplify things nicely:
	* don't need to drop an extra reference before the
call of kill_litter_super() in ->kill_sb(); all we need
there is to reset the cleanup list - everything on it will
be taken out automatically.
	* we can make use of simple_recursive_removal() on
tree rebuilds; just make sure that only children of root
end up in the cleanup list and hypfs_delete_tree() becomes
much simpler

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 57db9d42

arch/s390/hypfs/inode.c

+10 −31
Original line number Diff line number Diff line
@@ -61,33 +61,17 @@ static void hypfs_update_update(struct super_block *sb) 


static void hypfs_add_dentry(struct dentry *dentry)

{

	if (IS_ROOT(dentry->d_parent)) {

		dentry->d_fsdata = hypfs_last_dentry;

		hypfs_last_dentry = dentry;

	}



static void hypfs_remove(struct dentry *dentry)

{

	struct dentry *parent;



	parent = dentry->d_parent;

	inode_lock(d_inode(parent));

	if (simple_positive(dentry)) {

		if (d_is_dir(dentry))

			simple_rmdir(d_inode(parent), dentry);

		else

			simple_unlink(d_inode(parent), dentry);

	}

	d_drop(dentry);

	dput(dentry);

	inode_unlock(d_inode(parent));

}



static void hypfs_delete_tree(struct dentry *root)

static void hypfs_delete_tree(void)

{

	while (hypfs_last_dentry) {

		struct dentry *next_dentry;

		next_dentry = hypfs_last_dentry->d_fsdata;

		hypfs_remove(hypfs_last_dentry);

		struct dentry *next_dentry = hypfs_last_dentry->d_fsdata;

		simple_recursive_removal(hypfs_last_dentry, NULL);

		hypfs_last_dentry = next_dentry;

	}

}
@@ -184,14 +168,14 @@ static ssize_t hypfs_write_iter(struct kiocb *iocb, struct iov_iter *from) 
		rc = -EBUSY;

		goto out;

	}

	hypfs_delete_tree(sb->s_root);

	hypfs_delete_tree();

	if (machine_is_vm())

		rc = hypfs_vm_create_files(sb->s_root);

	else

		rc = hypfs_diag_create_files(sb->s_root);

	if (rc) {

		pr_err("Updating the hypfs tree failed\n");

		hypfs_delete_tree(sb->s_root);

		hypfs_delete_tree();

		goto out;

	}

	hypfs_update_update(sb);
@@ -326,13 +310,9 @@ static void hypfs_kill_super(struct super_block *sb) 
{

	struct hypfs_sb_info *sb_info = sb->s_fs_info;



	if (sb->s_root)

		hypfs_delete_tree(sb->s_root);

	if (sb_info && sb_info->update_file)

		hypfs_remove(sb_info->update_file);

	kfree(sb->s_fs_info);

	sb->s_fs_info = NULL;

	hypfs_last_dentry = NULL;

	kill_litter_super(sb);

	kfree(sb_info);

}



static struct dentry *hypfs_create_file(struct dentry *parent, const char *name,
@@ -367,7 +347,6 @@ static struct dentry *hypfs_create_file(struct dentry *parent, const char *name, 
		BUG();

	inode->i_private = data;

	d_instantiate(dentry, inode);

	dget(dentry);

fail:

	inode_unlock(d_inode(parent));

	return dentry;