Commit efad7153 authored by Miklos Szeredi's avatar Miklos Szeredi
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fuse: allow O_PATH fd for FUSE_DEV_IOC_BACKING_OPEN 



Only f_path is used from backing files registered with
FUSE_DEV_IOC_BACKING_OPEN, so it makes sense to allow O_PATH descriptors.

O_PATH files have an empty f_op, so don't check read_iter/write_iter.

Reviewed-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 862b9a8e

fs/fuse/passthrough.c

+2 −5
Original line number Diff line number Diff line
@@ -228,16 +228,13 @@ int fuse_backing_open(struct fuse_conn *fc, struct fuse_backing_map *map) 
	if (map->flags || map->padding)

		goto out;



	file = fget(map->fd);

	file = fget_raw(map->fd);

	res = -EBADF;

	if (!file)

		goto out;



	res = -EOPNOTSUPP;

	if (!file->f_op->read_iter || !file->f_op->write_iter)

		goto out_fput;



	backing_sb = file_inode(file)->i_sb;

	pr_info("%s: %x:%pD %i\n", __func__, backing_sb->s_dev, file, backing_sb->s_stack_depth);

	res = -ELOOP;

	if (backing_sb->s_stack_depth >= fc->max_stack_depth)

		goto out_fput;