For other backing subsystems, LIO core breaks SCSI commands that both
read and write (bidirectional cmds, or "BIDI") into read call to their
execute_rw function, followed by a write call to that function. This
keeps things simple for the backstore code.
However, for TCMU, we want userspace to handle the BIDI command in one
pass. Set execute_cmd and transport_complete_callback ptrs to NULL after
sbc_parse_cdb returns. We can't just skip calling sbc_parse_cdb -- it does
other setup for BIDI cmds that we need.
Reported-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Andy Grover <agrover@xxxxxxxxxx>
---
drivers/target/target_core_user.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 0e0feea..41fa012 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -1051,7 +1051,20 @@ static struct sbc_ops tcmu_sbc_ops = {
static sense_reason_t
tcmu_parse_cdb(struct se_cmd *cmd)
{
- return sbc_parse_cdb(cmd, &tcmu_sbc_ops);
+ sense_reason_t ret;
+
+ ret = sbc_parse_cdb(cmd, &tcmu_sbc_ops);
+
+ /*
+ * Since TCMU handles BIDI commands in one pass instead of two,
+ * fix things to work correctly.
+ */
+ if (cmd->se_cmd_flags & SCF_BIDI) {
+ cmd->execute_cmd = tcmu_pass_op;
+ cmd->transport_complete_callback = NULL;
+ }
+
+ return ret;
}
DEF_TB_DEFAULT_ATTRIBS(tcmu);
--
2.1.0
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