From mboxrd@z Thu Jan 1 00:00:00 1970 From: "K. Y. Srinivasan" Subject: [PATCH 2/2] Drivers: scsi: storvsc: Force discovery of LUNs that may have been removed. Date: Sat, 16 Aug 2014 20:09:48 -0700 Message-ID: <1408244988-27456-2-git-send-email-kys@microsoft.com> References: <1408244954-27417-1-git-send-email-kys@microsoft.com> <1408244988-27456-1-git-send-email-kys@microsoft.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1408244988-27456-1-git-send-email-kys@microsoft.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: driverdev-devel-bounces@linuxdriverproject.org Sender: driverdev-devel-bounces@linuxdriverproject.org To: hare@suse.de, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, ohering@suse.com, jbottomley@parallels.com, hch@infradead.org, linux-scsi@vger.kernel.org List-Id: linux-scsi@vger.kernel.org The host asks the guest to scan when a LUN is removed or added. The only way a guest can identify the removed LUN is when an I/O is attempted on a removed LUN - the SRB status code indicates that the LUN is invalid. We currently handle this SRB status and remove the device. Rather than waiting for an I/O to remove the device, force the discovery of LUNs that may have been removed prior to discovering LUNs that may have been added. Signed-off-by: K. Y. Srinivasan --- drivers/scsi/storvsc_drv.c | 26 ++++++++++++++++++++++++++ 1 files changed, 26 insertions(+), 0 deletions(-) diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c index 02d1db6..fb38ca9 100644 --- a/drivers/scsi/storvsc_drv.c +++ b/drivers/scsi/storvsc_drv.c @@ -430,10 +430,36 @@ static void storvsc_host_scan(struct work_struct *work) { struct storvsc_scan_work *wrk; struct Scsi_Host *host; + struct scsi_device *sdev; + unsigned long flags; wrk = container_of(work, struct storvsc_scan_work, work); host = wrk->host; + /* + * Before scanning the host, first check to see if any of the + * currrently known devices have been hot removed. We issue a + * "unit ready" command against all currently known devices. + * This I/O will result in an error for devices that have been + * removed. As part of handling the I/O error, we remove the device. + * + * When a LUN is added or removed, the host sends us a signal to + * scan the host. Thus we are forced to discover the LUNs that + * may have been removed this way. + */ + mutex_lock(&host->scan_mutex); + spin_lock_irqsave(host->host_lock, flags); + list_for_each_entry(sdev, &host->__devices, siblings) { + spin_unlock_irqrestore(host->host_lock, flags); + scsi_test_unit_ready(sdev, 1, 1, NULL); + spin_lock_irqsave(host->host_lock, flags); + continue; + } + spin_unlock_irqrestore(host->host_lock, flags); + mutex_unlock(&host->scan_mutex); + /* + * Now scan the host to discover LUNs that may have been added. + */ scsi_scan_host(host); kfree(wrk); -- 1.7.4.1