Re: [PATCH v5] scsi:iscsi: Fix multiple iscsi session unbind event sent to userspace

From: Lee Duncan
Date: Fri Oct 28 2022 - 11:05:33 EST


On 10/28/22 02:45, Wenchao Hao wrote:

On 2022/10/28 0:18, Lee Duncan wrote:
On 10/27/22 19:00, Wenchao Hao wrote:
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index cd3db9684e52..2e0d1cd6d4ea 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -1676,6 +1676,30 @@ static const char *iscsi_session_state_name(int state)
      return name;
  }
  +static struct {
+    int value;
+    char *name;
+} iscsi_session_target_state_names[] = {
+    { ISCSI_SESSION_TARGET_UNBOUND,        "UNBOUND" },
+    { ISCSI_SESSION_TARGET_ALLOCATED,    "ALLOCATED" },
+    { ISCSI_SESSION_TARGET_BOUND,        "BOUND" },
+    { ISCSI_SESSION_TARGET_UNBINDING,    "UNBINDING" },
+};
+
+static const char *iscsi_session_target_state_name(int state)
+{
+    int i;
+    char *name = NULL;
+
+    for (i = 0; i < ARRAY_SIZE(iscsi_session_target_state_names); i++) {
+        if (iscsi_session_target_state_names[i].value == state) {
+            name = iscsi_session_target_state_names[i].name;
+            break;
+        }
+    }
+    return name;
+}

It seems like it might be more efficient to use the target state as the array index, so you don't have to loop to find the name, e.g. something like:

static char* iscsi_session_target_state_names[] = {
     .ISCSI_SESSION_TARGET_UNBOUND = "UNBOUND",
     .ISCSI_SESSION_TARGET_ALLOCATED = "ALLOCATED",
     .ISCSI_SESSION_TARGET_BOUND = "BOUND",
     .ISCSI_SESSION_TARGET_UNBINDING = "UNBINDING",
};

I know there are only 4 states, and it's only used for sysfs, so not sure it matters much.


It's a better implement, I would update it.

@@ -1961,6 +1987,15 @@ static void __iscsi_unbind_session(struct work_struct *work)
      unsigned long flags;
      unsigned int target_id;
  +    spin_lock_irqsave(&session->lock, flags);
+    if (session->target_state != ISCSI_SESSION_TARGET_BOUND) {
+        spin_unlock_irqrestore(&session->lock, flags);
+        ISCSI_DBG_TRANS_SESSION(session, "Abort unbind sesison\n");

It'd be nice if this said more, since debugging "Abort unbind sessions" would require finding the sources. How about "Abort unbind session: not bound", for example?


Of course, I would updated.

@@ -264,6 +271,7 @@ struct iscsi_cls_session {
       */
      pid_t creator;
      int state;
+    int target_state;            /* session target bind state */
      int sid;                /* session id */
      void *dd_data;                /* LLD private data */
      struct device dev;    /* sysfs transport/container device */

Thank you for sticking with this. It is very much appreciated.

I should apologize for taking this issue off for a long time because of my slow response.

What's more, should I add an acked-by or reviewed-by in my next patch?

Please add my Reviewed-by tag after you make these changes.

And no problem taking a while. I appreciate your effort!
--
Lee Duncan