On Thu, Aug 07 2025, Chunsheng Luo wrote: > On Tue, Aug 05 2025, Miklos Szeredi wrote: > > + bytes_copied = fc->no_copy_file_range_64 ? > + outarg.size : outarg_64.bytes_copied; > + > truncate_inode_pages_range(inode_out->i_mapping, > ALIGN_DOWN(pos_out, PAGE_SIZE), > - ALIGN(pos_out + outarg.size, PAGE_SIZE) - 1); > + ALIGN(pos_out + bytes_copied, PAGE_SIZE) - 1); > > file_update_time(file_out); > - fuse_write_update_attr(inode_out, pos_out + outarg.size, outarg.size); > + fuse_write_update_attr(inode_out, pos_out + bytes_copied, bytes_copied); The copy_file_range syscall returns bytes_copied, a value provided by the userspace filesystem that the kernel cannot control. If bytes_copied > len, how should the application handle this? Similarly, if pos_out + bytes_copied < pos_outdue to integer overflow, could this cause any issues? Since vfs_copy_file_range->generic_copy_file_checks already check that pos_out + len does not overflow, so just need check bytes_copied > len. Thanks Chunsheng Luo
