cifs: smbd: Update receive credits before sending and deal with credits roll back...

Recevie credits should be updated before sending the packet, not
before a work is scheduled. Also, the value needs roll back if
something fails and cannot send.

Signed-off-by: Long Li <longli@microsoft.com>
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c
index c7ef2d7..fa52bf3 100644 (file)
--- a/fs/cifs/smbdirect.c
+++ b/fs/cifs/smbdirect.c
@@ -450,8 +450,6 @@ static void smbd_post_send_credits(struct work_struct *work)
        info->new_credits_offered += ret;
        spin_unlock(&info->lock_new_credits_offered);
 
-       atomic_add(ret, &info->receive_credits);
-
        /* Check if we can post new receive and grant credits to peer */
        check_and_send_immediate(info);
 }
@@ -822,6 +820,7 @@ static int smbd_create_header(struct smbd_connection *info,
        struct smbd_request *request;
        struct smbd_data_transfer *packet;
        int header_length;
+       int new_credits;
        int rc;
 
        /* Wait for send credits. A SMBD packet needs one credit */
@@ -840,7 +839,7 @@ static int smbd_create_header(struct smbd_connection *info,
        request = mempool_alloc(info->request_mempool, GFP_KERNEL);
        if (!request) {
                rc = -ENOMEM;
-               goto err;
+               goto err_alloc;
        }
 
        request->info = info;
@@ -848,8 +847,11 @@ static int smbd_create_header(struct smbd_connection *info,
        /* Fill in the packet header */
        packet = smbd_request_payload(request);
        packet->credits_requested = cpu_to_le16(info->send_credit_target);
-       packet->credits_granted =
-               cpu_to_le16(manage_credits_prior_sending(info));
+
+       new_credits = manage_credits_prior_sending(info);
+       atomic_add(new_credits, &info->receive_credits);
+       packet->credits_granted = cpu_to_le16(new_credits);
+
        info->send_immediate = false;
 
        packet->flags = 0;
@@ -887,7 +889,7 @@ static int smbd_create_header(struct smbd_connection *info,
        if (ib_dma_mapping_error(info->id->device, request->sge[0].addr)) {
                mempool_free(request, info->request_mempool);
                rc = -EIO;
-               goto err;
+               goto err_dma;
        }
 
        request->sge[0].length = header_length;
@@ -896,8 +898,17 @@ static int smbd_create_header(struct smbd_connection *info,
        *request_out = request;
        return 0;
 
-err:
+err_dma:
+       /* roll back receive credits */
+       spin_lock(&info->lock_new_credits_offered);
+       info->new_credits_offered += new_credits;
+       spin_unlock(&info->lock_new_credits_offered);
+       atomic_sub(new_credits, &info->receive_credits);
+
+err_alloc:
+       /* roll back send credits */
        atomic_inc(&info->send_credits);
+
        return rc;
 }