[PATCH next] iov_iter: fix copy_page_from_iter_atomic() Trying to test tmpfs on latest linux-next, copying and building kernel trees, huge pages, and swapping while swapping off involved: lots of cp: error writing '/tmp/2624/Documentation/fb/vesafb.txt': Bad address cp: error writing '/tmp/2624/arch/mips/math-emu/dp_fsp.c': Bad address etc. Bisection leads to next-20231006's 376fdc4552f1 ("iov_iter: Don't deal with iter->copy_mc in memcpy_from_iter_mc()") from vfs.git. The tweak below makes it healthy again: please feel free to fold in. Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx> --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -497,7 +497,7 @@ size_t copy_page_from_iter_atomic(struct } p = kmap_atomic(page) + offset; - __copy_from_iter(p, n, i); + n = __copy_from_iter(p, n, i); kunmap_atomic(p); copied += n; offset += n;