From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch adds TARGET_SCF_ACK_KREF for target_submit_cmd() that passes
a 'ack_kref' parameter into target_get_sess_cmd() to determine when
the fabric caller is expecting a second kref_put() from fabric
packet acknowledgement.
This also includes updating target_submit_cmd() usage in tcm_qla2xxx,
and target_get_sess_cmd() usage in ib_srpt ahead of a proper
target_submit_cmd() conversion in lio-core.
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Roland Dreier <roland@xxxxxxxxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/infiniband/ulp/srpt/ib_srpt.c | 2 +-
drivers/target/target_core_transport.c | 20 +++++++++++++++-----
drivers/target/tcm_qla2xxx/tcm_qla2xxx_fabric.c | 4 ++--
include/target/target_core_base.h | 1 +
include/target/target_core_transport.h | 2 +-
5 files changed, 20 insertions(+), 9 deletions(-)
diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
index 7699b49..ebe39d8 100644
--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -1752,7 +1752,7 @@ static int srpt_handle_cmd(struct srpt_rdma_ch *ch,
else
WARN_ON_ONCE(ret);
- target_get_sess_cmd(ch->sess, cmd);
+ target_get_sess_cmd(ch->sess, cmd, true);
transport_handle_cdb_direct(cmd);
return 0;
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index f1a8e2e..322eac9 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1708,10 +1708,12 @@ int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
data_length, data_dir, task_attr, sense);
/*
- * Obtain struct se_cmd->cmd_kref references and add new cmd to
- * se_sess->sess_cmd_list
+ * Obtain struct se_cmd->cmd_kref reference and add new cmd to
+ * se_sess->sess_cmd_list. A second kref_get here is necessary
+ * for fabrics using TARGET_SCF_ACK_KREF that expect a second
+ * kref_put() to happen during fabric packet acknowledgement.
*/
- target_get_sess_cmd(se_sess, se_cmd);
+ target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
/*
* Signal bidirectional data payloads to target-core
*/
@@ -3997,13 +3999,21 @@ EXPORT_SYMBOL(transport_generic_free_cmd);
/* target_get_sess_cmd - Add command to active ->sess_cmd_list
* @se_sess: session to reference
* @se_cmd: command descriptor to add
+ * @ack_kref: Signal that fabric will perform an ack target_put_sess_cmd()
*/
-void target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd)
+void target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
+ bool ack_kref)
{
unsigned long flags;
kref_init(&se_cmd->cmd_kref);
- kref_get(&se_cmd->cmd_kref);
+ /*
+ * Add a second kref if the fabric caller is expecting to handle
+ * fabric acknowledgement that requires two target_put_sess_cmd()
+ * invocations before se_cmd descriptor release.
+ */
+ if (ack_kref == true)
+ kref_get(&se_cmd->cmd_kref);
spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
diff --git a/drivers/target/tcm_qla2xxx/tcm_qla2xxx_fabric.c b/drivers/target/tcm_qla2xxx/tcm_qla2xxx_fabric.c
index 5386e82..14e388d 100644
--- a/drivers/target/tcm_qla2xxx/tcm_qla2xxx_fabric.c
+++ b/drivers/target/tcm_qla2xxx/tcm_qla2xxx_fabric.c
@@ -610,7 +610,7 @@ int tcm_qla2xxx_handle_cmd(scsi_qla_host_t *vha, struct qla_tgt_cmd *cmd,
struct se_cmd *se_cmd = &cmd->se_cmd;
struct se_session *se_sess;
struct qla_tgt_sess *sess;
- int rc;
+ int rc, flags = (bidi) ? TARGET_SCF_BIDI_OP : 0 | TARGET_SCF_ACK_KREF;
sess = cmd->sess;
if (!sess) {
@@ -626,7 +626,7 @@ int tcm_qla2xxx_handle_cmd(scsi_qla_host_t *vha, struct qla_tgt_cmd *cmd,
rc = target_submit_cmd(se_cmd, se_sess, cdb, &cmd->sense_buffer[0],
cmd->unpacked_lun, data_length, fcp_task_attr,
- data_dir, (bidi) ? TARGET_SCF_BIDI_OP : 0);
+ data_dir, flags);
if (rc != 0)
return -EINVAL;
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 3f7105b..81bd34c 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -158,6 +158,7 @@ enum tcm_sense_reason_table {
enum target_sc_flags_table {
TARGET_SCF_BIDI_OP = 0x01,
+ TARGET_SCF_ACK_KREF = 0x02,
};
struct se_obj {
diff --git a/include/target/target_core_transport.h b/include/target/target_core_transport.h
index 407aff9..b3e80e7 100644
--- a/include/target/target_core_transport.h
+++ b/include/target/target_core_transport.h
@@ -148,7 +148,7 @@ extern int transport_send_check_condition_and_sense(struct se_cmd *, u8, int);
extern void transport_send_task_abort(struct se_cmd *);
extern void transport_release_cmd(struct se_cmd *);
extern void transport_generic_free_cmd(struct se_cmd *, int);
-extern void target_get_sess_cmd(struct se_session *, struct se_cmd *);
+extern void target_get_sess_cmd(struct se_session *, struct se_cmd *, bool);
extern int target_put_sess_cmd(struct se_session *, struct se_cmd *);
extern void target_splice_sess_cmd_list(struct se_session *);
extern void target_wait_for_sess_cmds(struct se_session *, int);
--
1.7.2.5
--
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