Commit f62d5ccb authored by Shuhei Matsumoto's avatar Shuhei Matsumoto Committed by Changpeng Liu
Browse files

nvme/tcp: Properly handle multiple iovecs in nvme_tcp_pdu_set_data_buf 



nvme_tcp_pdu_set_data_buf() has been used to process C2H and H2C for
NVMe/TCP initiator.

In this case, NVMe/TCP cuts out the part of the input data buffer
and transfers the part, and repeats these cut and transfers until
the whole data buffer is transferred. NVMe/TCP uses two SGLs, and
use one to parse from the offset datao to datao + datal and another
to append from the offset 0 to datal.

However, the current nvme_tcp_pdu_set_data_buf() had used
data_length as not data length of this transfer but total length
of the whole transfers by mistake.

Recently DIF library updated to properly handle very similar
cases, and so this patch takes DIF library as a reference and
corrects the implementation.

The next patch will add UT code to verify the bug will be fixed.
The code size is pretty large and so UT code is separated.

Change-Id: Ibeed4de182b8b8740566e874e2757280dc21f9e8
Signed-off-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/455623


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
Reviewed-by: default avatarZiye Yang <ziye.yang@intel.com>
parent a7b6d2ef

lib/nvme/nvme_tcp.c

+43 −10
Original line number Diff line number Diff line
@@ -619,35 +619,68 @@ nvme_tcp_qpair_cmd_send_complete(void *cb_arg) 
{

}



static inline void

_nvme_tcp_sgl_advance(struct _nvme_tcp_sgl *s, uint32_t step)

{

	s->iov_offset += step;

	while (s->iovcnt > 0) {

		if (s->iov_offset < s->iov->iov_len) {

			break;

		}



		s->iov_offset -= s->iov->iov_len;

		s->iov++;

		s->iovcnt--;

	}

}



static inline void

_nvme_tcp_sgl_get_buf(struct _nvme_tcp_sgl *s, void **_buf, uint32_t *_buf_len)

{

	if (_buf != NULL) {

		*_buf = s->iov->iov_base + s->iov_offset;

	}

	if (_buf_len != NULL) {

		*_buf_len = s->iov->iov_len - s->iov_offset;

	}

}



static void

nvme_tcp_pdu_set_data_buf(struct nvme_tcp_pdu *pdu,

			  struct iovec *iov, int iovcnt,

			  uint32_t data_offset, uint32_t data_len)

{

	uint32_t i, remain_len, len;

	struct _nvme_tcp_sgl *pdu_sgl;

	uint32_t remain_len, len;

	uint8_t *buf;

	struct _nvme_tcp_sgl *pdu_sgl, buf_sgl;



	if (iovcnt == 1) {

		nvme_tcp_pdu_set_data(pdu, (void *)((uint64_t)iov[0].iov_base + data_offset), data_len);

	} else {

		i = 0;

		pdu_sgl = &pdu->sgl;

		assert(iovcnt <= NVME_TCP_MAX_SGL_DESCRIPTORS);

		_nvme_tcp_sgl_init(pdu_sgl, pdu->data_iov, iovcnt, data_offset);



		_nvme_tcp_sgl_init(pdu_sgl, pdu->data_iov, NVME_TCP_MAX_SGL_DESCRIPTORS, 0);

		_nvme_tcp_sgl_init(&buf_sgl, iov, iovcnt, 0);



		_nvme_tcp_sgl_advance(&buf_sgl, data_offset);

		remain_len = data_len;



		while (remain_len > 0) {

			assert(i < NVME_TCP_MAX_SGL_DESCRIPTORS);

			len = spdk_min(remain_len, iov[i].iov_len);

			_nvme_tcp_sgl_get_buf(&buf_sgl, (void *)&buf, &len);

			len = spdk_min(len, remain_len);



			_nvme_tcp_sgl_advance(&buf_sgl, len);

			remain_len -= len;

			if (!_nvme_tcp_sgl_append(pdu_sgl, iov[i].iov_base, len)) {



			if (!_nvme_tcp_sgl_append(pdu_sgl, buf, len)) {

				break;

			}

			i++;

		}



		assert(remain_len == 0);

		pdu->data_iovcnt = iovcnt - pdu_sgl->iovcnt;

		assert(pdu_sgl->total_size == data_len);



		pdu->data_iovcnt = NVME_TCP_MAX_SGL_DESCRIPTORS - pdu_sgl->iovcnt;

		pdu->data_len = data_len;

	}

}