From 63e359d42119d803912e5f24dc1c56d168acedeb Mon Sep 17 00:00:00 2001 From: Sreekanth Reddy Date: Thu, 25 Jul 2013 11:32:51 +0530 Subject: [PATCH] [SCSI] mpt2sas: Fix for kernel panic when driver loads with HBA connected to non LUN 0 configured expander With some enclosures when LUN 0 is not created but LUN 1 or LUN X is created then SCSI scan procedure calls target_alloc, slave_alloc call back functions for LUN 0 and slave_destory() for same LUN 0. In these kind of cases within slave_destroy, pointer to scsi_target in _sas_device structure is set to NULL, following which when slave_alloc for LUN 1 is called then starget would not be set properly for this LUN. So, scsi_target pointer pointing to NULL value would lead to a crash later in the discovery procedure. To solve this issue set the sas_device's scsi_target pointer to scsi_device's scsi_target if it is NULL earlier in slave_alloc callback function. Signed-off-by: Sreekanth Reddy Signed-off-by: James Bottomley --- drivers/scsi/mpt2sas/mpt2sas_scsih.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/scsi/mpt2sas/mpt2sas_scsih.c b/drivers/scsi/mpt2sas/mpt2sas_scsih.c index 481afe6..7f0af4f 100644 --- a/drivers/scsi/mpt2sas/mpt2sas_scsih.c +++ b/drivers/scsi/mpt2sas/mpt2sas_scsih.c @@ -1403,6 +1403,7 @@ _scsih_slave_alloc(struct scsi_device *sdev) struct MPT2SAS_DEVICE *sas_device_priv_data; struct scsi_target *starget; struct _raid_device *raid_device; + struct _sas_device *sas_device; unsigned long flags; sas_device_priv_data = kzalloc(sizeof(struct scsi_device), GFP_KERNEL); @@ -1431,6 +1432,19 @@ _scsih_slave_alloc(struct scsi_device *sdev) spin_unlock_irqrestore(&ioc->raid_device_lock, flags); } + if (!(sas_target_priv_data->flags & MPT_TARGET_FLAGS_VOLUME)) { + spin_lock_irqsave(&ioc->sas_device_lock, flags); + sas_device = mpt2sas_scsih_sas_device_find_by_sas_address(ioc, + sas_target_priv_data->sas_address); + if (sas_device && (sas_device->starget == NULL)) { + sdev_printk(KERN_INFO, sdev, + "%s : sas_device->starget set to starget @ %d\n", + __func__, __LINE__); + sas_device->starget = starget; + } + spin_unlock_irqrestore(&ioc->sas_device_lock, flags); + } + return 0; } -- 2.7.4