Commit 9900b9fe authored by Yi Kuo's avatar Yi Kuo Committed by Steve French
Browse files

smb: smbdirect: fix MR registration for coalesced SG lists 

ib_dma_map_sg() modifies the provided scatterlist and returns the
number of mapped entries, which can be fewer than the requested
mr->sgt.nents if the DMA controller coalesces contiguous memory
segments. Passing the original, uncoalesced count to ib_map_mr_sg()
causes memory registration failures if coalescing actually occurs.

Capture the actual mapped count returned by ib_dma_map_sg() and pass it
to ib_map_mr_sg() to ensure correct MR registration.

Also update the ib_dma_map_sg() error logging to drop the error
pointer formatting, since the return value is an integer count
rather than an error code.

Ensure a proper error code (-EIO) is assigned when DMA mapping or
MR registration fails.

Fixes: de5ef8ec ("smb: smbdirect: introduce smbdirect_mr.c with client mr code")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221408


Reviewed-by: default avatarStefan Metzmacher <metze@samba.org>
Acked-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
Signed-off-by: default avatarYi Kuo <yi@yikuo.dev>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent e768103c

fs/smb/smbdirect/mr.c

+12 −9
Original line number Diff line number Diff line
@@ -269,7 +269,7 @@ smbdirect_connection_register_mr_io(struct smbdirect_socket *sc, 
{

	const struct smbdirect_socket_parameters *sp = &sc->parameters;

	struct smbdirect_mr_io *mr;

	int ret, num_pages;

	int ret, num_pages, num_mapped;

	struct ib_reg_wr *reg_wr;



	num_pages = iov_iter_npages(iter, sp->max_frmr_depth + 1);
@@ -300,19 +300,22 @@ smbdirect_connection_register_mr_io(struct smbdirect_socket *sc, 
		num_pages, iov_iter_count(iter), sp->max_frmr_depth);

	smbdirect_iter_to_sgt(iter, &mr->sgt, sp->max_frmr_depth);



	ret = ib_dma_map_sg(sc->ib.dev, mr->sgt.sgl, mr->sgt.nents, mr->dir);

	if (!ret) {

	num_mapped = ib_dma_map_sg(sc->ib.dev, mr->sgt.sgl, mr->sgt.nents, mr->dir);

	if (!num_mapped) {

		smbdirect_log_rdma_mr(sc, SMBDIRECT_LOG_ERR,

			"ib_dma_map_sg num_pages=%u dir=%x ret=%d (%1pe)\n",

			num_pages, mr->dir, ret, SMBDIRECT_DEBUG_ERR_PTR(ret));

			"ib_dma_map_sg num_pages=%u dir=%x num_mapped=%d\n",

			num_pages, mr->dir, num_mapped);

		ret = -EIO;

		goto dma_map_error;

	}



	ret = ib_map_mr_sg(mr->mr, mr->sgt.sgl, mr->sgt.nents, NULL, PAGE_SIZE);

	if (ret != mr->sgt.nents) {

	ret = ib_map_mr_sg(mr->mr, mr->sgt.sgl, num_mapped, NULL, PAGE_SIZE);

	if (ret != num_mapped) {

		smbdirect_log_rdma_mr(sc, SMBDIRECT_LOG_ERR,

			"ib_map_mr_sg failed ret = %d nents = %u\n",

			ret, mr->sgt.nents);

			"ib_map_mr_sg failed ret = %d num_mapped = %u\n",

			ret, num_mapped);

		if (ret >= 0)

			ret = -EIO;

		goto map_mr_error;

	}