smb: client: introduce and use smbd_{alloc, free}_send_io()

This is basically a copy of smb_direct_{alloc,free}_sendmsg()
in the server, with just using ib_dma_unmap_page() in all
cases, which is the same as ib_dma_unmap_single().

We'll use this logic in common code in future.
(I basically backported it from my branch that
as already has everything in common).

Cc: <stable@vger.kernel.org> # 6.18.x
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/smb/client/smbdirect.c b/fs/smb/client/smbdirect.c
index 75c0ac9cc65c73d806f0d365589b665c099da43b..6cb40da7e5897ca6e2d4081225564e318ffc6e8e 100644 (file)
--- a/fs/smb/client/smbdirect.c
+++ b/fs/smb/client/smbdirect.c
@@ -493,10 +493,54 @@ static inline void *smbdirect_recv_io_payload(struct smbdirect_recv_io *response
        return (void *)response->packet;
 }
 
+static struct smbdirect_send_io *smbd_alloc_send_io(struct smbdirect_socket *sc)
+{
+       struct smbdirect_send_io *msg;
+
+       msg = mempool_alloc(sc->send_io.mem.pool, GFP_KERNEL);
+       if (!msg)
+               return ERR_PTR(-ENOMEM);
+       msg->socket = sc;
+       INIT_LIST_HEAD(&msg->sibling_list);
+       msg->num_sge = 0;
+
+       return msg;
+}
+
+static void smbd_free_send_io(struct smbdirect_send_io *msg)
+{
+       struct smbdirect_socket *sc = msg->socket;
+       size_t i;
+
+       /*
+        * The list needs to be empty!
+        * The caller should take care of it.
+        */
+       WARN_ON_ONCE(!list_empty(&msg->sibling_list));
+
+       /*
+        * Note we call ib_dma_unmap_page(), even if some sges are mapped using
+        * ib_dma_map_single().
+        *
+        * The difference between _single() and _page() only matters for the
+        * ib_dma_map_*() case.
+        *
+        * For the ib_dma_unmap_*() case it does not matter as both take the
+        * dma_addr_t and dma_unmap_single_attrs() is just an alias to
+        * dma_unmap_page_attrs().
+        */
+       for (i = 0; i < msg->num_sge; i++)
+               ib_dma_unmap_page(sc->ib.dev,
+                                 msg->sge[i].addr,
+                                 msg->sge[i].length,
+                                 DMA_TO_DEVICE);
+
+       mempool_free(msg, sc->send_io.mem.pool);
+}
+
 /* Called when a RDMA send is done */
 static void send_done(struct ib_cq *cq, struct ib_wc *wc)
 {
-       int i;
        struct smbdirect_send_io *request =
                container_of(wc->wr_cqe, struct smbdirect_send_io, cqe);
        struct smbdirect_socket *sc = request->socket;
@@ -505,12 +549,8 @@ static void send_done(struct ib_cq *cq, struct ib_wc *wc)
        log_rdma_send(INFO, "smbdirect_send_io 0x%p completed wc->status=%s\n",
                request, ib_wc_status_msg(wc->status));
 
-       for (i = 0; i < request->num_sge; i++)
-               ib_dma_unmap_single(sc->ib.dev,
-                       request->sge[i].addr,
-                       request->sge[i].length,
-                       DMA_TO_DEVICE);
-       mempool_free(request, sc->send_io.mem.pool);
+       /* Note this frees wc->wr_cqe, but not wc */
+       smbd_free_send_io(request);
        lcredits += 1;
 
        if (wc->status != IB_WC_SUCCESS || wc->opcode != IB_WC_SEND) {
@@ -963,15 +1003,13 @@ static int smbd_post_send_negotiate_req(struct smbdirect_socket *sc)
 {
        struct smbdirect_socket_parameters *sp = &sc->parameters;
        struct ib_send_wr send_wr;
-       int rc = -ENOMEM;
+       int rc;
        struct smbdirect_send_io *request;
        struct smbdirect_negotiate_req *packet;
 
-       request = mempool_alloc(sc->send_io.mem.pool, GFP_KERNEL);
-       if (!request)
-               return rc;
-
-       request->socket = sc;
+       request = smbd_alloc_send_io(sc);
+       if (IS_ERR(request))
+               return PTR_ERR(request);
 
        packet = smbdirect_send_io_payload(request);
        packet->min_version = cpu_to_le16(SMBDIRECT_V1);
@@ -983,7 +1021,6 @@ static int smbd_post_send_negotiate_req(struct smbdirect_socket *sc)
        packet->max_fragmented_size =
                cpu_to_le32(sp->max_fragmented_recv_size);
 
-       request->num_sge = 1;
        request->sge[0].addr = ib_dma_map_single(
                                sc->ib.dev, (void *)packet,
                                sizeof(*packet), DMA_TO_DEVICE);
@@ -991,6 +1028,7 @@ static int smbd_post_send_negotiate_req(struct smbdirect_socket *sc)
                rc = -EIO;
                goto dma_mapping_failed;
        }
+       request->num_sge = 1;
 
        request->sge[0].length = sizeof(*packet);
        request->sge[0].lkey = sc->ib.pd->local_dma_lkey;
@@ -1020,13 +1058,11 @@ static int smbd_post_send_negotiate_req(struct smbdirect_socket *sc)
        /* if we reach here, post send failed */
        log_rdma_send(ERR, "ib_post_send failed rc=%d\n", rc);
        atomic_dec(&sc->send_io.pending.count);
-       ib_dma_unmap_single(sc->ib.dev, request->sge[0].addr,
-               request->sge[0].length, DMA_TO_DEVICE);
 
        smbd_disconnect_rdma_connection(sc);
 
 dma_mapping_failed:
-       mempool_free(request, sc->send_io.mem.pool);
+       smbd_free_send_io(request);
        return rc;
 }
 
@@ -1187,7 +1223,7 @@ static int smbd_post_send_iter(struct smbdirect_socket *sc,
                               int *_remaining_data_length)
 {
        struct smbdirect_socket_parameters *sp = &sc->parameters;
-       int i, rc;
+       int rc;
        int header_length;
        int data_length;
        struct smbdirect_send_io *request;
@@ -1208,13 +1244,12 @@ static int smbd_post_send_iter(struct smbdirect_socket *sc,
                goto err_wait_credit;
        }
 
-       request = mempool_alloc(sc->send_io.mem.pool, GFP_KERNEL);
-       if (!request) {
-               rc = -ENOMEM;
+       request = smbd_alloc_send_io(sc);
+       if (IS_ERR(request)) {
+               rc = PTR_ERR(request);
                goto err_alloc;
        }
 
-       request->socket = sc;
        memset(request->sge, 0, sizeof(request->sge));
 
        /* Map the packet to DMA */
@@ -1292,13 +1327,7 @@ static int smbd_post_send_iter(struct smbdirect_socket *sc,
                return 0;
 
 err_dma:
-       for (i = 0; i < request->num_sge; i++)
-               if (request->sge[i].addr)
-                       ib_dma_unmap_single(sc->ib.dev,
-                                           request->sge[i].addr,
-                                           request->sge[i].length,
-                                           DMA_TO_DEVICE);
-       mempool_free(request, sc->send_io.mem.pool);
+       smbd_free_send_io(request);
 
 err_alloc:
        atomic_inc(&sc->send_io.credits.count);