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Message-Id: <1326400688-13544-7-git-send-email-kys@microsoft.com>
Date: Thu, 12 Jan 2012 12:38:00 -0800
From: "K. Y. Srinivasan" <kys@...rosoft.com>
To: gregkh@...e.de, linux-kernel@...r.kernel.org,
devel@...uxdriverproject.org, virtualization@...ts.osdl.org,
ohering@...e.com, jbottomley@...allels.com, hch@...radead.org,
linux-scsi@...r.kernel.org
Cc: "K. Y. Srinivasan" <kys@...rosoft.com>
Subject: [PATCH 07/15] Staging: hv: storvsc: Add a comment to explain life-cycle management
Add a comment to explain life-cycle management and fix format issue.
Signed-off-by: K. Y. Srinivasan <kys@...rosoft.com>
---
drivers/staging/hv/storvsc_drv.c | 17 ++++++++++++++++-
1 files changed, 16 insertions(+), 1 deletions(-)
diff --git a/drivers/staging/hv/storvsc_drv.c b/drivers/staging/hv/storvsc_drv.c
index e0e471c..204b3ca 100644
--- a/drivers/staging/hv/storvsc_drv.c
+++ b/drivers/staging/hv/storvsc_drv.c
@@ -375,6 +375,21 @@ done:
kfree(wrk);
}
+/*
+ * We can get incoming messages from the host that are not in response to
+ * messages that we have sent out. An example of this would be messages
+ * received by the guest to notify dynamic addition/removal of LUNs. To
+ * deal with potential race conditions where the driver may be in the
+ * midst of being unloaded when we might receive an unsolicited message
+ * from the host, we have implemented a mechanism to gurantee sequential
+ * consistency:
+ *
+ * 1) Once the device is marked as being destroyed, we will fail all
+ * outgoing messages.
+ * 2) We permit incoming messages when the device is being destroyed,
+ * only to properly account for messages already sent out.
+ */
+
static inline struct storvsc_device *get_out_stor_device(
struct hv_device *device)
{
@@ -569,7 +584,7 @@ static void storvsc_on_io_completion(struct hv_device *device,
*/
if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
- (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
+ (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
vstor_packet->vm_srb.scsi_status = 0;
vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
}
--
1.7.4.1
--
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