scsi: bnx2fc: Fix hung task messages when a cleanup response is not received during...

If a cleanup task is not responded to while we are in bnx2fc_abts_cleanup, it
will hang the SCSI error handler since we use wait_for_completion instead of
wait_for_completion_timeout.  So, use wait_for_completion_timeout so that we
don't hang the SCSI error handler thread forever.

Fixes the call trace:

[183373.131468] INFO: task scsi_eh_16:110146 blocked for more than 120 seconds.
[183373.131469] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[183373.131470] scsi_eh_16      D ffff88103f2fca14     0 110146      2 0x00000080
[183373.131472]  ffff880855e77cb0 0000000000000046 ffff881050654e70 ffff880855e77fd8
[183373.131474]  ffff880855e77fd8 ffff880855e77fd8 ffff881050654e70 ffff88103f2fcb48
[183373.131475]  ffff88103f2fcb50 7fffffffffffffff ffff881050654e70 ffff88103f2fca14
[183373.131477] Call Trace:
[183373.131479]  [<ffffffff8168b579>] schedule+0x29/0x70
[183373.131481]  [<ffffffff81688fc9>] schedule_timeout+0x239/0x2d0
[183373.131486]  [<ffffffff8142821e>] ? __dev_printk+0x3e/0x90
[183373.131487]  [<ffffffff814282cd>] ? dev_printk+0x5d/0x80
[183373.131490]  [<ffffffff8168b956>] wait_for_completion+0x116/0x170
[183373.131492]  [<ffffffff810c4ec0>] ? wake_up_state+0x20/0x20
[183373.131494]  [<ffffffffa048c234>] bnx2fc_abts_cleanup+0x3d/0x62 [bnx2fc]
[183373.131497]  [<ffffffffa0483a80>] bnx2fc_eh_abort+0x470/0x580 [bnx2fc]
[183373.131500]  [<ffffffff814570af>] scsi_error_handler+0x59f/0x8b0
[183373.131501]  [<ffffffff81456b10>] ? scsi_eh_get_sense+0x250/0x250
[183373.131503]  [<ffffffff810b052f>] kthread+0xcf/0xe0
[183373.131505]  [<ffffffff810b0460>] ? kthread_create_on_node+0x140/0x140
[183373.131507]  [<ffffffff81696418>] ret_from_fork+0x58/0x90
[183373.131509]  [<ffffffff810b0460>] ? kthread_create_on_node+0x140/0x140

Signed-off-by: Chad Dupuis <chad.dupuis@cavium.com>
Reviewed-by: Laurence Oberman <loberman@redhat.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/bnx2fc/bnx2fc_io.c b/drivers/scsi/bnx2fc/bnx2fc_io.c
index 5b6153f..8e2f767 100644 (file)
--- a/drivers/scsi/bnx2fc/bnx2fc_io.c
+++ b/drivers/scsi/bnx2fc/bnx2fc_io.c
@@ -1084,24 +1084,35 @@ static int bnx2fc_abts_cleanup(struct bnx2fc_cmd *io_req)
 {
        struct bnx2fc_rport *tgt = io_req->tgt;
        int rc = SUCCESS;
+       unsigned int time_left;
 
        io_req->wait_for_comp = 1;
        bnx2fc_initiate_cleanup(io_req);
 
        spin_unlock_bh(&tgt->tgt_lock);
 
-       wait_for_completion(&io_req->tm_done);
-
+       /*
+        * Can't wait forever on cleanup response lest we let the SCSI error
+        * handler wait forever
+        */
+       time_left = wait_for_completion_timeout(&io_req->tm_done,
+                                               BNX2FC_FW_TIMEOUT);
        io_req->wait_for_comp = 0;
+       if (!time_left)
+               BNX2FC_IO_DBG(io_req, "%s(): Wait for cleanup timed out.\n",
+                             __func__);
+
        /*
-        * release the reference taken in eh_abort to allow the
-        * target to re-login after flushing IOs
+        * Release reference held by SCSI command the cleanup completion
+        * hits the BNX2FC_CLEANUP case in bnx2fc_process_cq_compl() and
+        * thus the SCSI command is not returnedi by bnx2fc_scsi_done().
         */
        kref_put(&io_req->refcount, bnx2fc_cmd_release);
 
        spin_lock_bh(&tgt->tgt_lock);
        return rc;
 }
+
 /**
  * bnx2fc_eh_abort - eh_abort_handler api to abort an outstanding
  *                     SCSI command
@@ -1118,6 +1129,7 @@ int bnx2fc_eh_abort(struct scsi_cmnd *sc_cmd)
        struct fc_lport *lport;
        struct bnx2fc_rport *tgt;
        int rc;
+       unsigned int time_left;
 
        rc = fc_block_scsi_eh(sc_cmd);
        if (rc)
@@ -1194,6 +1206,11 @@ int bnx2fc_eh_abort(struct scsi_cmnd *sc_cmd)
                if (cancel_delayed_work(&io_req->timeout_work))
                        kref_put(&io_req->refcount,
                                 bnx2fc_cmd_release); /* drop timer hold */
+               /*
+                * We don't want to hold off the upper layer timer so simply
+                * cleanup the command and return that I/O was successfully
+                * aborted.
+                */
                rc = bnx2fc_abts_cleanup(io_req);
                /* This only occurs when an task abort was requested while ABTS
                   is in progress.  Setting the IO_CLEANUP flag will skip the
@@ -1201,7 +1218,7 @@ int bnx2fc_eh_abort(struct scsi_cmnd *sc_cmd)
                   was a result from the ABTS request rather than the CLEANUP
                   request */
                set_bit(BNX2FC_FLAG_IO_CLEANUP, &io_req->req_flags);
-               goto out;
+               goto done;
        }
 
        /* Cancel the current timer running on this io_req */
@@ -1221,7 +1238,11 @@ int bnx2fc_eh_abort(struct scsi_cmnd *sc_cmd)
        }
        spin_unlock_bh(&tgt->tgt_lock);
 
-       wait_for_completion(&io_req->tm_done);
+       /* Wait 2 * RA_TOV + 1 to be sure timeout function hasn't fired */
+       time_left = wait_for_completion_timeout(&io_req->tm_done,
+           (2 * rp->r_a_tov + 1) * HZ);
+       if (time_left)
+               BNX2FC_IO_DBG(io_req, "Timed out in eh_abort waiting for tm_done");
 
        spin_lock_bh(&tgt->tgt_lock);
        io_req->wait_for_comp = 0;
@@ -1233,8 +1254,12 @@ int bnx2fc_eh_abort(struct scsi_cmnd *sc_cmd)
                /* Let the scsi-ml try to recover this command */
                printk(KERN_ERR PFX "abort failed, xid = 0x%x\n",
                       io_req->xid);
+               /*
+                * Cleanup firmware residuals before returning control back
+                * to SCSI ML.
+                */
                rc = bnx2fc_abts_cleanup(io_req);
-               goto out;
+               goto done;
        } else {
                /*
                 * We come here even when there was a race condition
@@ -1249,7 +1274,6 @@ int bnx2fc_eh_abort(struct scsi_cmnd *sc_cmd)
 done:
        /* release the reference taken in eh_abort */
        kref_put(&io_req->refcount, bnx2fc_cmd_release);
-out:
        spin_unlock_bh(&tgt->tgt_lock);
        return rc;
 }