| Message ID | 20221028023352.3532080-2-viro@zeniv.linux.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2,01/12] get rid of unlikely() on page_copy_sane() calls | expand |
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index e9a8fc9ee8ee..020e009d71c5 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1549,8 +1549,12 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *_csstate, __wsum sum, next; if (unlikely(iov_iter_is_discard(i))) { - WARN_ON(1); /* for now */ - return 0; + // can't use csum_memcpy() for that one - data is not copied + csstate->csum = csum_block_add(csstate->csum, + csum_partial(addr, bytes, 0), + csstate->off); + csstate->off += bytes; + return bytes; } sum = csum_shift(csstate->csum, csstate->off);
Not hard to implement - we are not copying anything here, so csum_and_memcpy() is not usable, but calculating a checksum of source directly is trivial... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> --- lib/iov_iter.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)