IB/srp: Fix srp_map_sg_fr()

After dma_map_sg() has been called the return value of that function
must be used as the number of elements in the scatterlist instead of
scsi_sg_count().

Fixes: commit f7f7aab1a5c0 ("IB/srp: Convert to new registration API")
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: stable <stable@vger.kernel.org> # v4.4+
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index fac1423..3db9a65 100644 (file)
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -1313,7 +1313,7 @@ reset_state:
 }
 
 static int srp_map_finish_fr(struct srp_map_state *state,
-                            struct srp_rdma_ch *ch)
+                            struct srp_rdma_ch *ch, int sg_nents)
 {
        struct srp_target_port *target = ch->target;
        struct srp_device *dev = target->srp_host->srp_dev;
@@ -1328,10 +1328,10 @@ static int srp_map_finish_fr(struct srp_map_state *state,
 
        WARN_ON_ONCE(!dev->use_fast_reg);
 
-       if (state->sg_nents == 0)
+       if (sg_nents == 0)
                return 0;
 
-       if (state->sg_nents == 1 && target->global_mr) {
+       if (sg_nents == 1 && target->global_mr) {
                srp_map_desc(state, sg_dma_address(state->sg),
                             sg_dma_len(state->sg),
                             target->global_mr->rkey);
@@ -1345,8 +1345,7 @@ static int srp_map_finish_fr(struct srp_map_state *state,
        rkey = ib_inc_rkey(desc->mr->rkey);
        ib_update_fast_reg_key(desc->mr, rkey);
 
-       n = ib_map_mr_sg(desc->mr, state->sg, state->sg_nents,
-                        dev->mr_page_size);
+       n = ib_map_mr_sg(desc->mr, state->sg, sg_nents, dev->mr_page_size);
        if (unlikely(n < 0))
                return n;
 
@@ -1452,16 +1451,15 @@ static int srp_map_sg_fr(struct srp_map_state *state, struct srp_rdma_ch *ch,
        state->fr.next = req->fr_list;
        state->fr.end = req->fr_list + ch->target->cmd_sg_cnt;
        state->sg = scat;
-       state->sg_nents = scsi_sg_count(req->scmnd);
 
-       while (state->sg_nents) {
+       while (count) {
                int i, n;
 
-               n = srp_map_finish_fr(state, ch);
+               n = srp_map_finish_fr(state, ch, count);
                if (unlikely(n < 0))
                        return n;
 
-               state->sg_nents -= n;
+               count -= n;
                for (i = 0; i < n; i++)
                        state->sg = sg_next(state->sg);
        }
@@ -1521,13 +1519,12 @@ static int srp_map_idb(struct srp_rdma_ch *ch, struct srp_request *req,
 
        if (dev->use_fast_reg) {
                state.sg = idb_sg;
-               state.sg_nents = 1;
                sg_set_buf(idb_sg, req->indirect_desc, idb_len);
                idb_sg->dma_address = req->indirect_dma_addr; /* hack! */
 #ifdef CONFIG_NEED_SG_DMA_LENGTH
                idb_sg->dma_length = idb_sg->length;          /* hack^2 */
 #endif
-               ret = srp_map_finish_fr(&state, ch);
+               ret = srp_map_finish_fr(&state, ch, 1);
                if (ret < 0)
                        return ret;
        } else if (dev->use_fmr) {

diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h
index 87a2a91..f6af531 100644 (file)
--- a/drivers/infiniband/ulp/srp/ib_srp.h
+++ b/drivers/infiniband/ulp/srp/ib_srp.h
@@ -300,10 +300,7 @@ struct srp_map_state {
        dma_addr_t              base_dma_addr;
        u32                     dma_len;
        u32                     total_len;
-       union {
-               unsigned int    npages;
-               int             sg_nents;
-       };
+       unsigned int            npages;
        unsigned int            nmdesc;
        unsigned int            ndesc;
 };