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Commit 80527240 authored by Chuck Lever's avatar Chuck Lever Committed by Anna Schumaker
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xprtrdma: Byte-align FRWR registration 



The RPC/RDMA transport's FRWR registration logic registers whole
pages. This means areas in the first and last pages that are not
involved in the RDMA I/O are needlessly exposed to the server.

Buffered I/O is typically page-aligned, so not a problem there. But
for direct I/O, which can be byte-aligned, and for reply chunks,
which are nearly always smaller than a page, the transport could
expose memory outside the I/O buffer.

FRWR allows byte-aligned memory registration, so let's use it as
it was intended.

Reported-by: default avatarSagi Grimberg <sagig@mellanox.com>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Tested-by: default avatarDevesh Sharma <Devesh.Sharma@Emulex.Com>
Tested-by: default avatarMeghana Cheripady <Meghana.Cheripady@Emulex.Com>
Tested-by: default avatarVeeresh U. Kokatnur <veereshuk@chelsio.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent e2377945

net/sunrpc/xprtrdma/verbs.c

+4 −8
Original line number Diff line number Diff line
@@ -1924,23 +1924,19 @@ rpcrdma_register_frmr_external(struct rpcrdma_mr_seg *seg, 
		    offset_in_page((seg-1)->mr_offset + (seg-1)->mr_len))

			break;

	}

	dprintk("RPC:       %s: Using frmr %p to map %d segments\n",

		__func__, mw, i);

	dprintk("RPC:       %s: Using frmr %p to map %d segments (%d bytes)\n",

		__func__, mw, i, len);



	frmr->fr_state = FRMR_IS_VALID;



	memset(&fastreg_wr, 0, sizeof(fastreg_wr));

	fastreg_wr.wr_id = (unsigned long)(void *)mw;

	fastreg_wr.opcode = IB_WR_FAST_REG_MR;

	fastreg_wr.wr.fast_reg.iova_start = seg1->mr_dma;

	fastreg_wr.wr.fast_reg.iova_start = seg1->mr_dma + pageoff;

	fastreg_wr.wr.fast_reg.page_list = frmr->fr_pgl;

	fastreg_wr.wr.fast_reg.page_list_len = page_no;

	fastreg_wr.wr.fast_reg.page_shift = PAGE_SHIFT;

	fastreg_wr.wr.fast_reg.length = page_no << PAGE_SHIFT;

	if (fastreg_wr.wr.fast_reg.length < len) {

		rc = -EIO;

		goto out_err;

	}

	fastreg_wr.wr.fast_reg.length = len;



	/* Bump the key */

	key = (u8)(mr->rkey & 0x000000FF);