target/user: Free data ring in unified function

Prepare for data_bitmap in the next patch.

Reviewed-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Sheng Yang <sheng@yasker.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 93de51f..baa8720 100644 (file)
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -303,6 +303,11 @@ static void alloc_and_scatter_data_area(struct tcmu_dev *udev,
        }
 }
 
+static void free_data_area(struct tcmu_dev *udev, size_t length)
+{
+       UPDATE_HEAD(udev->data_tail, length, udev->data_size);
+}
+
 static void gather_and_free_data_area(struct tcmu_dev *udev,
        struct scatterlist *data_sg, unsigned int data_nents)
 {
@@ -323,7 +328,7 @@ static void gather_and_free_data_area(struct tcmu_dev *udev,
                tcmu_flush_dcache_range(from, copy_bytes);
                memcpy(to, from, copy_bytes);
 
-               UPDATE_HEAD(udev->data_tail, copy_bytes, udev->data_size);
+               free_data_area(udev, copy_bytes);
 
                /* Uh oh, wrapped the data buffer for this sg's data */
                if (sg->length != copy_bytes) {
@@ -336,8 +341,7 @@ static void gather_and_free_data_area(struct tcmu_dev *udev,
                        tcmu_flush_dcache_range(from, copy_bytes);
                        memcpy(to_skip, from, copy_bytes);
 
-                       UPDATE_HEAD(udev->data_tail,
-                               copy_bytes, udev->data_size);
+                       free_data_area(udev, copy_bytes);
                }
                kunmap_atomic(to - sg->offset);
        }
@@ -543,24 +547,22 @@ static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *
        if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
                /* cmd has been completed already from timeout, just reclaim data
                   ring space */
-               UPDATE_HEAD(udev->data_tail, cmd->data_length, udev->data_size);
+               free_data_area(udev, cmd->data_length);
                return;
        }
 
        if (entry->hdr.uflags & TCMU_UFLAG_UNKNOWN_OP) {
-               UPDATE_HEAD(udev->data_tail, cmd->data_length, udev->data_size);
+               free_data_area(udev, cmd->data_length);
                pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n",
                        cmd->se_cmd);
                entry->rsp.scsi_status = SAM_STAT_CHECK_CONDITION;
        } else if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) {
                memcpy(se_cmd->sense_buffer, entry->rsp.sense_buffer,
                               se_cmd->scsi_sense_length);
-
-               UPDATE_HEAD(udev->data_tail, cmd->data_length, udev->data_size);
+               free_data_area(udev, cmd->data_length);
        } else if (se_cmd->se_cmd_flags & SCF_BIDI) {
                /* Discard data_out buffer */
-               UPDATE_HEAD(udev->data_tail,
-                       (size_t)se_cmd->t_data_sg->length, udev->data_size);
+               free_data_area(udev, (size_t)se_cmd->t_data_sg->length);
 
                /* Get Data-In buffer */
                gather_and_free_data_area(udev,
@@ -569,7 +571,7 @@ static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *
                gather_and_free_data_area(udev,
                        se_cmd->t_data_sg, se_cmd->t_data_nents);
        } else if (se_cmd->data_direction == DMA_TO_DEVICE) {
-               UPDATE_HEAD(udev->data_tail, cmd->data_length, udev->data_size);
+               free_data_area(udev, cmd->data_length);
        } else if (se_cmd->data_direction != DMA_NONE) {
                pr_warn("TCMU: data direction was %d!\n",
                        se_cmd->data_direction);