ksmbd: smbd: fix dma_unmap_sg() nents

The dma_unmap_sg() functions should be called with the same nents as the
dma_map_sg(), not the value the map function returned.

Fixes: 0626e6641f6b ("cifsd: add server handler for central processing and tranport layers")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/smb/server/transport_rdma.c b/fs/smb/server/transport_rdma.c
index f585359684d450287c3d3aad6bb02d1c031acdf5..8620690aa2ec0ae1cc95124c6ac70ba6bc9138d4 100644 (file)
--- a/fs/smb/server/transport_rdma.c
+++ b/fs/smb/server/transport_rdma.c
@@ -1353,14 +1353,12 @@ static int get_sg_list(void *buf, int size, struct scatterlist *sg_list, int nen
 
 static int get_mapped_sg_list(struct ib_device *device, void *buf, int size,
                              struct scatterlist *sg_list, int nentries,
-                             enum dma_data_direction dir)
+                             enum dma_data_direction dir, int *npages)
 {
-       int npages;
-
-       npages = get_sg_list(buf, size, sg_list, nentries);
-       if (npages < 0)
+       *npages = get_sg_list(buf, size, sg_list, nentries);
+       if (*npages < 0)
                return -EINVAL;
-       return ib_dma_map_sg(device, sg_list, npages, dir);
+       return ib_dma_map_sg(device, sg_list, *npages, dir);
 }
 
 static int post_sendmsg(struct smbdirect_socket *sc,
@@ -1431,12 +1429,13 @@ static int smb_direct_post_send_data(struct smbdirect_socket *sc,
        for (i = 0; i < niov; i++) {
                struct ib_sge *sge;
                int sg_cnt;
+               int npages;
 
                sg_init_table(sg, SMBDIRECT_SEND_IO_MAX_SGE - 1);
                sg_cnt = get_mapped_sg_list(sc->ib.dev,
                                            iov[i].iov_base, iov[i].iov_len,
                                            sg, SMBDIRECT_SEND_IO_MAX_SGE - 1,
-                                           DMA_TO_DEVICE);
+                                           DMA_TO_DEVICE, &npages);
                if (sg_cnt <= 0) {
                        pr_err("failed to map buffer\n");
                        ret = -ENOMEM;
@@ -1444,7 +1443,7 @@ static int smb_direct_post_send_data(struct smbdirect_socket *sc,
                } else if (sg_cnt + msg->num_sge > SMBDIRECT_SEND_IO_MAX_SGE) {
                        pr_err("buffer not fitted into sges\n");
                        ret = -E2BIG;
-                       ib_dma_unmap_sg(sc->ib.dev, sg, sg_cnt,
+                       ib_dma_unmap_sg(sc->ib.dev, sg, npages,
                                        DMA_TO_DEVICE);
                        goto err;
                }