[SCSI] mpt2sas: Fix for dead lock occurring between host_lock and sas_device_lock
Fix for dead lock occurring between host_lock and sas_device_lock.
The deadlock is between two spin locks, between the shost->host_lock
and driver ioc->sas_device_lock.
The fix is to rearrange the code in the FW/Driver device removal
handshake so the ioc->sas_device_lock is not occurring when the
shost->host_lock is taken.
[jejb: zero initialise sas_address to fix spurious compiler warning]
Signed-off-by: Nagalakshmi Nandigama <nagalakshmi.nandigama@lsi.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/mpt2sas/mpt2sas_scsih.c b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
index cd89f42..f9ce3195 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_scsih.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
@@ -3016,7 +3016,8 @@
Mpi2SCSITaskManagementRequest_t *mpi_request;
u16 smid;
struct _sas_device *sas_device;
- struct MPT2SAS_TARGET *sas_target_priv_data;
+ struct MPT2SAS_TARGET *sas_target_priv_data = NULL;
+ u64 sas_address = 0;
unsigned long flags;
struct _tr_list *delayed_tr;
u32 ioc_state;
@@ -3049,13 +3050,17 @@
sas_device->starget->hostdata) {
sas_target_priv_data = sas_device->starget->hostdata;
sas_target_priv_data->deleted = 1;
- dewtprintk(ioc, printk(MPT2SAS_INFO_FMT
- "setting delete flag: handle(0x%04x), "
- "sas_addr(0x%016llx)\n", ioc->name, handle,
- (unsigned long long) sas_device->sas_address));
+ sas_address = sas_device->sas_address;
}
spin_unlock_irqrestore(&ioc->sas_device_lock, flags);
+ if (sas_target_priv_data) {
+ dewtprintk(ioc, printk(MPT2SAS_INFO_FMT "setting delete flag: "
+ "handle(0x%04x), sas_addr(0x%016llx)\n", ioc->name, handle,
+ (unsigned long long)sas_address));
+ _scsih_ublock_io_device(ioc, handle);
+ }
+
smid = mpt2sas_base_get_smid_hpr(ioc, ioc->tm_tr_cb_idx);
if (!smid) {
delayed_tr = kzalloc(sizeof(*delayed_tr), GFP_ATOMIC);