2020-05-02 10:34 GMT+09:00, Eric Sandeen <sandeen@xxxxxxxxxxx>:
> Doing copy_file_range() on exfat with a file opened for direct IO leads
> to an -EFAULT:
>
> # xfs_io -f -d -c "truncate 32768" \
> -c "copy_range -d 16384 -l 16384 -f 0" /mnt/test/junk
> copy_range: Bad address
>
> and the reason seems to be that we go through:
>
> default_file_splice_write
> splice_from_pipe
> __splice_from_pipe
> write_pipe_buf
> __kernel_write
> new_sync_write
> generic_file_write_iter
> generic_file_direct_write
> exfat_direct_IO
> do_blockdev_direct_IO
> iov_iter_get_pages
>
> and land in iterate_all_kinds(), which does "return -EFAULT" for our kvec
> iter.
>
> Setting exfat's splice_write to iter_file_splice_write fixes this and lets
> fsx (which originally detected the problem) run to success from the
> xfstests
> harness.
>
> Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxxx>
Applied:)
Thanks!
> ---
>
> I know that's not a good changelog; I conferred with viro about whether
> this
> is correct, but I still don't have a great explanation, so feel free to fix
> up
> the changelog to be more informative if the change is otherwise correct...
>
> diff --git a/fs/exfat/file.c b/fs/exfat/file.c
> index 4f76764165cf..c9db8eb0cfc3 100644
> --- a/fs/exfat/file.c
> +++ b/fs/exfat/file.c
> @@ -348,12 +348,13 @@ int exfat_setattr(struct dentry *dentry, struct iattr
> *attr)
> }
>
> const struct file_operations exfat_file_operations = {
> - .llseek = generic_file_llseek,
> - .read_iter = generic_file_read_iter,
> - .write_iter = generic_file_write_iter,
> - .mmap = generic_file_mmap,
> - .fsync = generic_file_fsync,
> - .splice_read = generic_file_splice_read,
> + .llseek = generic_file_llseek,
> + .read_iter = generic_file_read_iter,
> + .write_iter = generic_file_write_iter,
> + .mmap = generic_file_mmap,
> + .fsync = generic_file_fsync,
> + .splice_read = generic_file_splice_read,
> + .splice_write = iter_file_splice_write,
> };
>
> const struct inode_operations exfat_file_inode_operations = {
>
>
>
