A number of users have reported that under certain conditions using Docker and overlay2, copy_file_range() can unexpectedly create a 0-byte file: In https://github.com/docker/for-linux/issues/1015. We started seeing mysterious failures in our CI tests as a result of files not properly being copied. https://github.com/docker/for-linux/issues/1015#issuecomment-841915668 has a sample reproduction test. I analyzed the diff between 5.10 and 5.11 and found that if I applied the following kernel patch, the reproduction test passes: https://lore.kernel.org/linux-fsdevel/20201207163255.564116-6-mszeredi@xxxxxxxxxx/#t This landed in this merge commit and this commit: 1. https://github.com/torvalds/linux/commit/92dbc9dedccb9759c7f9f2f0ae6242396376988f 2. https://github.com/torvalds/linux/commit/82a763e61e2b601309d696d4fa514c77d64ee1be Could this patch be backported for kernels 5.6 to 5.10?
