Merge tag 'v4.0.8' into xlnx_4.0.8-rt6

[zynq/linux.git] / drivers / target / target_core_transport.c

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 0adc0f6502134eb3292a7a2cab66ac75be4d6406..f786de0290db782830ff9d1f40babb1d0fc93b21 100644 (file)
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1615,11 +1615,11 @@ void transport_generic_request_failure(struct se_cmd *cmd,
        transport_complete_task_attr(cmd);
        /*
         * Handle special case for COMPARE_AND_WRITE failure, where the
-        * callback is expected to drop the per device ->caw_mutex.
+        * callback is expected to drop the per device ->caw_sem.
         */
        if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
             cmd->transport_complete_callback)
-               cmd->transport_complete_callback(cmd);
+               cmd->transport_complete_callback(cmd, false);
 
        switch (sense_reason) {
        case TCM_NON_EXISTENT_LUN:
@@ -1975,8 +1975,12 @@ static void target_complete_ok_work(struct work_struct *work)
        if (cmd->transport_complete_callback) {
                sense_reason_t rc;
 
-               rc = cmd->transport_complete_callback(cmd);
+               rc = cmd->transport_complete_callback(cmd, true);
                if (!rc && !(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE_POST)) {
+                       if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
+                           !cmd->data_length)
+                               goto queue_rsp;
+
                        return;
                } else if (rc) {
                        ret = transport_send_check_condition_and_sense(cmd,
@@ -1990,6 +1994,7 @@ static void target_complete_ok_work(struct work_struct *work)
                }
        }
 
+queue_rsp:
        switch (cmd->data_direction) {
        case DMA_FROM_DEVICE:
                spin_lock(&cmd->se_lun->lun_sep_lock);
@@ -2094,6 +2099,16 @@ static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
 static inline void transport_free_pages(struct se_cmd *cmd)
 {
        if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
+               /*
+                * Release special case READ buffer payload required for
+                * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
+                */
+               if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
+                       transport_free_sgl(cmd->t_bidi_data_sg,
+                                          cmd->t_bidi_data_nents);
+                       cmd->t_bidi_data_sg = NULL;
+                       cmd->t_bidi_data_nents = 0;
+               }
                transport_reset_sgl_orig(cmd);
                return;
        }
@@ -2246,6 +2261,7 @@ sense_reason_t
 transport_generic_new_cmd(struct se_cmd *cmd)
 {
        int ret = 0;
+       bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
 
        /*
         * Determine is the TCM fabric module has already allocated physical
@@ -2254,7 +2270,6 @@ transport_generic_new_cmd(struct se_cmd *cmd)
         */
        if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
            cmd->data_length) {
-               bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
 
                if ((cmd->se_cmd_flags & SCF_BIDI) ||
                    (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
@@ -2285,6 +2300,20 @@ transport_generic_new_cmd(struct se_cmd *cmd)
                                       cmd->data_length, zero_flag);
                if (ret < 0)
                        return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+       } else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
+                   cmd->data_length) {
+               /*
+                * Special case for COMPARE_AND_WRITE with fabrics
+                * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
+                */
+               u32 caw_length = cmd->t_task_nolb *
+                                cmd->se_dev->dev_attrib.block_size;
+
+               ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
+                                      &cmd->t_bidi_data_nents,
+                                      caw_length, zero_flag);
+               if (ret < 0)
+                       return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
        }
        /*
         * If this command is not a write we can execute it right here,
@@ -2389,6 +2418,10 @@ int target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
        list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
 out:
        spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
+
+       if (ret && ack_kref)
+               target_put_sess_cmd(se_sess, se_cmd);
+
        return ret;
 }
 EXPORT_SYMBOL(target_get_sess_cmd);