From: Mike Christie <michaelc@xxxxxxxxxxx>
Patch and mail from both MikeC and HannesR:
Before we're trying to send a PDU we have to check whether a TMF
is active. If so and if the PDU will be affected by the TMF
we should allow only Data-out PDUs to be sent.
If fast_abort is set, no Data-out PDUs will be sent while
a LUN reset is being processed for a affected LUN.
fast_abort is now ingored during a ABORT TASK tmf. We will not
send any Data-outs for a task if the task is being aborted.
Signed-off-by: Mike Christie <michaelc@xxxxxxxxxxx>
Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
---
drivers/scsi/libiscsi.c | 113 +++++++++++++++++++++++++++++++++++++++-----
include/scsi/iscsi_proto.h | 2 +
2 files changed, 103 insertions(+), 12 deletions(-)
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 8c29480..b6ffdc5 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -266,6 +266,88 @@ static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
}
/**
+ * iscsi_check_tmf_restrictions - check if a task is affected by TMF
+ * @task: iscsi task
+ * @opcode: opcode to check for
+ *
+ * During TMF a task has to be checked if it's affected.
+ * All unrelated I/O can be passed through, but I/O to the
+ * affected LUN should be restricted.
+ * If 'fast_abort' is set we won't be sending any I/O to the
+ * affected LUN.
+ * Otherwise the target is waiting for all TTTs to be completed,
+ * so we have to send all outstanding Data-Out PDUs to the target.
+ */
+static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
+{
+ struct iscsi_conn *conn = task->conn;
+ struct iscsi_tm *tmf = &conn->tmhdr;
+ unsigned int hdr_lun;
+
+ if (conn->tmf_state == TMF_INITIAL)
+ return 0;
+
+ if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
+ return 0;
+
+ switch (ISCSI_TM_FUNC_VALUE(tmf)) {
+ case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
+ /*
+ * Allow PDUs for unrelated LUNs
+ */
+ hdr_lun = scsilun_to_int((struct scsi_lun *)tmf->lun);
+ if (hdr_lun != task->sc->device->lun)
+ return 0;
+
+ /*
+ * Fail all SCSI cmd PDUs
+ */
+ if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
+ iscsi_conn_printk(KERN_INFO, conn,
+ "task [op %x/%x itt "
+ "0x%x/0x%x lun %u] "
+ "rejected.\n",
+ task->hdr->opcode, opcode,
+ task->itt, task->hdr_itt, hdr_lun);
+ return -EACCES;
+ }
+ /*
+ * And also all data-out PDUs in response to R2T
+ * if fast_abort is set.
+ */
+ if (conn->session->fast_abort) {
+ iscsi_conn_printk(KERN_INFO, conn,
+ "task [op %x/%x itt "
+ "0x%x/0x%x lun %u] "
+ "fast abort.\n",
+ task->hdr->opcode, opcode,
+ task->itt, task->hdr_itt, hdr_lun);
+ return -EACCES;
+ }
+ break;
+ case ISCSI_TM_FUNC_ABORT_TASK:
+ /*
+ * the caller has already checked if the task
+ * they want to abort was in the pending queue so if
+ * we are here the cmd pdu has gone out already, and
+ * we will only hit this for data-outs
+ */
+ if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
+ task->hdr_itt == tmf->rtt) {
+ ISCSI_DBG_SESSION(conn->session,
+ "Preventing task %x/%x from sending "
+ "data-out due to abort task in "
+ "progress\n", task->itt,
+ task->hdr_itt);
+ return -EACCES;
+ }
+ break;
+ }
+
+ return 0;
+}
+
+/**
* iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
* @task: iscsi task
*
@@ -282,6 +364,10 @@ static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
itt_t itt;
int rc;
+ rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
+ if (rc)
+ return rc;
+
if (conn->session->tt->alloc_pdu) {
rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
if (rc)
@@ -1366,6 +1452,7 @@ EXPORT_SYMBOL_GPL(iscsi_requeue_task);
**/
static int iscsi_data_xmit(struct iscsi_conn *conn)
{
+ struct iscsi_task *task;
int rc = 0;
spin_lock_bh(&conn->session->lock);
@@ -1403,11 +1490,8 @@ check_mgmt:
/* process pending command queue */
while (!list_empty(&conn->cmdqueue)) {
- if (conn->tmf_state == TMF_QUEUED)
- break;
-
- conn->task = list_entry(conn->cmdqueue.next,
- struct iscsi_task, running);
+ conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
+ running);
list_del_init(&conn->task->running);
if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
fail_scsi_task(conn->task, DID_IMM_RETRY);
@@ -1415,7 +1499,7 @@ check_mgmt:
}
rc = iscsi_prep_scsi_cmd_pdu(conn->task);
if (rc) {
- if (rc == -ENOMEM) {
+ if (rc == -ENOMEM || rc == -EACCES) {
list_add_tail(&conn->task->running,
&conn->cmdqueue);
conn->task = NULL;
@@ -1437,17 +1521,18 @@ check_mgmt:
}
while (!list_empty(&conn->requeue)) {
- if (conn->session->fast_abort && conn->tmf_state != TMF_INITIAL)
- break;
-
/*
* we always do fastlogout - conn stop code will clean up.
*/
if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
break;
- conn->task = list_entry(conn->requeue.next,
- struct iscsi_task, running);
+ task = list_entry(conn->requeue.next, struct iscsi_task,
+ running);
+ if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
+ break;
+
+ conn->task = task;
list_del_init(&conn->task->running);
conn->task->state = ISCSI_TASK_RUNNING;
rc = iscsi_xmit_task(conn);
@@ -1600,7 +1685,7 @@ int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
if (!ihost->workq) {
reason = iscsi_prep_scsi_cmd_pdu(task);
if (reason) {
- if (reason == -ENOMEM) {
+ if (reason == -ENOMEM || reason == -EACCES) {
reason = FAILURE_OOM;
goto prepd_reject;
} else {
@@ -2120,6 +2205,7 @@ int iscsi_eh_abort(struct scsi_cmnd *sc)
spin_lock_bh(&session->lock);
fail_scsi_task(task, DID_ABORT);
conn->tmf_state = TMF_INITIAL;
+ memset(hdr, 0, sizeof(*hdr));
spin_unlock_bh(&session->lock);
iscsi_start_tx(conn);
goto success_unlocked;
@@ -2130,6 +2216,7 @@ int iscsi_eh_abort(struct scsi_cmnd *sc)
case TMF_NOT_FOUND:
if (!sc->SCp.ptr) {
conn->tmf_state = TMF_INITIAL;
+ memset(hdr, 0, sizeof(*hdr));
/* task completed before tmf abort response */
ISCSI_DBG_EH(session, "sc completed while abort in "
"progress\n");
@@ -2224,6 +2311,7 @@ int iscsi_eh_device_reset(struct scsi_cmnd *sc)
iscsi_suspend_tx(conn);
spin_lock_bh(&session->lock);
+ memset(hdr, 0, sizeof(*hdr));
fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
conn->tmf_state = TMF_INITIAL;
spin_unlock_bh(&session->lock);
@@ -2868,6 +2956,7 @@ static void iscsi_start_session_recovery(struct iscsi_session *session,
spin_lock_bh(&session->lock);
fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
fail_mgmt_tasks(session, conn);
+ memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
spin_unlock_bh(&session->lock);
mutex_unlock(&session->eh_mutex);
}
diff --git a/include/scsi/iscsi_proto.h b/include/scsi/iscsi_proto.h
index f2a2c11..dd0a52c 100644
--- a/include/scsi/iscsi_proto.h
+++ b/include/scsi/iscsi_proto.h
@@ -279,6 +279,8 @@ struct iscsi_tm {
#define ISCSI_TM_FUNC_TARGET_COLD_RESET 7
#define ISCSI_TM_FUNC_TASK_REASSIGN 8
+#define ISCSI_TM_FUNC_VALUE(hdr) ((hdr)->flags & ISCSI_FLAG_TM_FUNC_MASK)
+
/* SCSI Task Management Response Header */
struct iscsi_tm_rsp {
uint8_t opcode;
--
1.6.2.2
--
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