Commit c0d91fb9 authored by Miklos Szeredi's avatar Miklos Szeredi
Browse files

ovl: split out ovl_get_lower_layers() from ovl_fill_super() 



Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 8ed61dc3

fs/overlayfs/super.c

+52 −38
Original line number Diff line number Diff line
@@ -1038,6 +1038,55 @@ static int ovl_get_lowerstack(struct super_block *sb, struct ovl_fs *ufs, 
	goto out;

}



static int ovl_get_lower_layers(struct ovl_fs *ufs, struct path *stack,

				unsigned int numlower)

{

	int err;

	unsigned int i;



	err = -ENOMEM;

	ufs->lower_layers = kcalloc(numlower, sizeof(struct ovl_layer),

				    GFP_KERNEL);

	if (ufs->lower_layers == NULL)

		goto out;

	for (i = 0; i < numlower; i++) {

		struct vfsmount *mnt;

		dev_t dev;



		err = get_anon_bdev(&dev);

		if (err) {

			pr_err("overlayfs: failed to get anonymous bdev for lowerpath\n");

			goto out;

		}



		mnt = clone_private_mount(&stack[i]);

		err = PTR_ERR(mnt);

		if (IS_ERR(mnt)) {

			pr_err("overlayfs: failed to clone lowerpath\n");

			free_anon_bdev(dev);

			goto out;

		}

		/*

		 * Make lower layers R/O.  That way fchmod/fchown on lower file

		 * will fail instead of modifying lower fs.

		 */

		mnt->mnt_flags |= MNT_READONLY | MNT_NOATIME;



		ufs->lower_layers[ufs->numlower].mnt = mnt;

		ufs->lower_layers[ufs->numlower].pseudo_dev = dev;

		ufs->numlower++;



		/* Check if all lower layers are on same sb */

		if (i == 0)

			ufs->same_sb = mnt->mnt_sb;

		else if (ufs->same_sb != mnt->mnt_sb)

			ufs->same_sb = NULL;

	}

	err = 0;

out:

	return err;

}



static int ovl_fill_super(struct super_block *sb, void *data, int silent)

{

	struct path upperpath = { };
@@ -1103,44 +1152,9 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) 
			goto out_put_workdir;

	}



	err = -ENOMEM;

	ufs->lower_layers = kcalloc(numlower, sizeof(struct ovl_layer),

				    GFP_KERNEL);

	if (ufs->lower_layers == NULL)

		goto out_put_workdir;

	for (i = 0; i < numlower; i++) {

		struct vfsmount *mnt;

		dev_t dev;



		err = get_anon_bdev(&dev);

		if (err) {

			pr_err("overlayfs: failed to get anonymous bdev for lowerpath\n");

			goto out_put_lower_layers;

		}



		mnt = clone_private_mount(&stack[i]);

		err = PTR_ERR(mnt);

		if (IS_ERR(mnt)) {

			pr_err("overlayfs: failed to clone lowerpath\n");

			free_anon_bdev(dev);

	err = ovl_get_lower_layers(ufs, stack, numlower);

	if (err)

		goto out_put_lower_layers;

		}

		/*

		 * Make lower layers R/O.  That way fchmod/fchown on lower file

		 * will fail instead of modifying lower fs.

		 */

		mnt->mnt_flags |= MNT_READONLY | MNT_NOATIME;



		ufs->lower_layers[ufs->numlower].mnt = mnt;

		ufs->lower_layers[ufs->numlower].pseudo_dev = dev;

		ufs->numlower++;



		/* Check if all lower layers are on same sb */

		if (i == 0)

			ufs->same_sb = mnt->mnt_sb;

		else if (ufs->same_sb != mnt->mnt_sb)

			ufs->same_sb = NULL;

	}



	/* If the upper fs is nonexistent, we mark overlayfs r/o too */

	if (!ufs->upper_mnt)