lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <1434102153-38581-20-git-send-email-Sreekanth.Reddy@avagotech.com>
Date:	Fri, 12 Jun 2015 15:12:31 +0530
From:	Sreekanth Reddy <sreekanth.reddy@...gotech.com>
To:	jejb@...nel.org, hch@...radead.org
Cc:	martin.petersen@...cle.com, linux-scsi@...r.kernel.org,
	JBottomley@...allels.com, Sathya.Prakash@...gotech.com,
	linux-kernel@...r.kernel.org,
	Sreekanth Reddy <Sreekanth.Reddy@...gotech.com>
Subject: [PATCH 19/20] [SCSI] mpt3sas: When device is blocked followed by unblock fails, unfreeze the I/Os

Issue: When the disks are getting discovered and assigned device
handles by the kernel, a device block followed by an unblock
(due to broadcast primitives) issued by the driver is
interspersed by the kernel changing the state of the device.
Therefore the unblock by the driver results in a no operation
within the kernel API.

To fix this one, the below patch checks the return of the unblock API
and performs a block followed by an unblock to unfreeze the block
layer's I/O queue. Sufficient checks and prints are also added in the
driver to identify this condition caused by the kernel.

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@...gotech.com>
---
 drivers/scsi/mpt3sas/mpt3sas_scsih.c | 89 ++++++++++++++++++++++++++++++------
 1 file changed, 75 insertions(+), 14 deletions(-)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
index 42bb731..5405a2f 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
@@ -2605,6 +2605,75 @@ _scsih_fw_event_cleanup_queue(struct MPT3SAS_ADAPTER *ioc)
 }
 
 /**
+ * _scsih_internal_device_block - block the sdev device
+ * @sdev: per device object
+ * @sas_device_priv_data : per device driver private data
+ *
+ * make sure device is blocked without error, if not
+ * print an error
+ */
+static void
+_scsih_internal_device_block(struct scsi_device *sdev,
+			struct MPT3SAS_DEVICE *sas_device_priv_data)
+{
+	int r = 0;
+
+	sdev_printk(KERN_INFO, sdev, "device_block, handle(0x%04x)\n",
+	    sas_device_priv_data->sas_target->handle);
+	sas_device_priv_data->block = 1;
+
+	r = scsi_internal_device_block(sdev);
+	if (r == -EINVAL)
+		sdev_printk(KERN_WARNING, sdev,
+		    "device_block failed with return(%d) for handle(0x%04x)\n",
+		    sas_device_priv_data->sas_target->handle, r);
+}
+
+/**
+ * _scsih_internal_device_unblock - unblock the sdev device
+ * @sdev: per device object
+ * @sas_device_priv_data : per device driver private data
+ * make sure device is unblocked without error, if not retry
+ * by blocking and then unblocking
+ */
+
+static void
+_scsih_internal_device_unblock(struct scsi_device *sdev,
+			struct MPT3SAS_DEVICE *sas_device_priv_data)
+{
+	int r = 0;
+
+	sdev_printk(KERN_WARNING, sdev, "device_unblock and setting to running, "
+	    "handle(0x%04x)\n", sas_device_priv_data->sas_target->handle);
+	sas_device_priv_data->block = 0;
+	r = scsi_internal_device_unblock(sdev, SDEV_RUNNING);
+	if (r == -EINVAL) {
+		/* The device has been set to SDEV_RUNNING by SD layer during
+		 * device addition but the request queue is still stopped by
+		 * our earlier block call. We need to perform a block again
+		 * to get the device to SDEV_BLOCK and then to SDEV_RUNNING */
+
+		sdev_printk(KERN_WARNING, sdev,
+		    "device_unblock failed with return(%d) for handle(0x%04x) "
+		    "performing a block followed by an unblock\n",
+		    sas_device_priv_data->sas_target->handle, r);
+		sas_device_priv_data->block = 1;
+		r = scsi_internal_device_block(sdev);
+		if (r)
+			sdev_printk(KERN_WARNING, sdev, "retried device_block "
+			    "failed with return(%d) for handle(0x%04x)\n",
+			    sas_device_priv_data->sas_target->handle, r);
+
+		sas_device_priv_data->block = 0;
+		r = scsi_internal_device_unblock(sdev, SDEV_RUNNING);
+		if (r)
+			sdev_printk(KERN_WARNING, sdev, "retried device_unblock"
+			    " failed with return(%d) for handle(0x%04x)\n",
+			    sas_device_priv_data->sas_target->handle, r);
+	}
+}
+
+/**
  * _scsih_ublock_io_all_device - unblock every device
  * @ioc: per adapter object
  *
@@ -2623,11 +2692,10 @@ _scsih_ublock_io_all_device(struct MPT3SAS_ADAPTER *ioc)
 		if (!sas_device_priv_data->block)
 			continue;
 
-		sas_device_priv_data->block = 0;
 		dewtprintk(ioc, sdev_printk(KERN_INFO, sdev,
 			"device_running, handle(0x%04x)\n",
 		    sas_device_priv_data->sas_target->handle));
-		scsi_internal_device_unblock(sdev, SDEV_RUNNING);
+		_scsih_internal_device_unblock(sdev, sas_device_priv_data);
 	}
 }
 
@@ -2652,10 +2720,9 @@ _scsih_ublock_io_device(struct MPT3SAS_ADAPTER *ioc, u64 sas_address)
 		if (sas_device_priv_data->sas_target->sas_address
 		    != sas_address)
 			continue;
-		if (sas_device_priv_data->block) {
-			sas_device_priv_data->block = 0;
-			scsi_internal_device_unblock(sdev, SDEV_RUNNING);
-		}
+		if (sas_device_priv_data->block)
+			_scsih_internal_device_unblock(sdev,
+				sas_device_priv_data);
 	}
 }
 
@@ -2678,10 +2745,7 @@ _scsih_block_io_all_device(struct MPT3SAS_ADAPTER *ioc)
 			continue;
 		if (sas_device_priv_data->block)
 			continue;
-		sas_device_priv_data->block = 1;
-		scsi_internal_device_block(sdev);
-		sdev_printk(KERN_INFO, sdev, "device_blocked, handle(0x%04x)\n",
-		    sas_device_priv_data->sas_target->handle);
+		_scsih_internal_device_block(sdev, sas_device_priv_data);
 	}
 }
 
@@ -2713,10 +2777,7 @@ _scsih_block_io_device(struct MPT3SAS_ADAPTER *ioc, u16 handle)
 			continue;
 		if (sas_device->pend_sas_rphy_add)
 			continue;
-		sas_device_priv_data->block = 1;
-		scsi_internal_device_block(sdev);
-		sdev_printk(KERN_INFO, sdev,
-			"device_blocked, handle(0x%04x)\n", handle);
+		_scsih_internal_device_block(sdev, sas_device_priv_data);
 	}
 }
 
-- 
2.0.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ