- Fixes incorrect allocation length 0 by scst_user module

[mirror/scst/.git] / scst / src / scst_lib.c

diff --git a/scst/src/scst_lib.c b/scst/src/scst_lib.c
index 2b1638b..e4d0a9c 100644 (file)
--- a/scst/src/scst_lib.c
+++ b/scst/src/scst_lib.c
@@ -1657,6 +1657,7 @@ int scst_alloc_space(struct scst_cmd *cmd)
                flags |= SCST_POOL_ALLOC_NO_CACHED;
 
        if (unlikely(cmd->bufflen == 0)) {
+               /* ToDo: remove when 1.0.1 will be started */
                TRACE(TRACE_MGMT_MINOR, "Warning: data direction %d or/and "
                        "zero buffer length. Opcode 0x%x, handler %s, target "
                        "%s", cmd->data_direction, cmd->cdb[0],
@@ -1811,6 +1812,14 @@ static int get_trans_len_1(struct scst_cmd *cmd, uint8_t off)
        return 0;
 }
 
+static int get_trans_len_1_256(struct scst_cmd *cmd, uint8_t off)
+{
+       cmd->bufflen = (u32)cmd->cdb[off];
+       if (cmd->bufflen == 0)
+               cmd->bufflen = 256;
+       return 0;
+}
+
 static int get_trans_len_2(struct scst_cmd *cmd, uint8_t off)
 {
        const uint8_t *p = cmd->cdb + off;
@@ -1907,6 +1916,15 @@ int scst_get_cdb_info(struct scst_cmd *cmd)
        cmd->data_direction = ptr->direction;
        cmd->op_flags = ptr->flags;
        res = (*ptr->get_trans_len)(cmd, ptr->off);
+#if 0 /* ToDo: enable when 1.0.1 will be started and fix all scst_get_buf_first() returns 0 cases */
+       if (unlikely(cmd->bufflen == 0)) {
+               /*
+                * According to SPC bufflen 0 for data transfer commands isn't
+                * an error, so we need to fix the transfer direction.
+                */
+               cmd->data_direction = SCST_DATA_NONE;
+       }
+#endif
 
 out:
        TRACE_EXIT();