From f3db032f1af6dd3280037ea526fee7cddcc36c41 Mon Sep 17 00:00:00 2001 From: "nagalakshmi.nandigama@lsi.com" Date: Wed, 19 Oct 2011 15:37:14 +0530 Subject: [PATCH] [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 Signed-off-by: James Bottomley --- drivers/scsi/mpt2sas/mpt2sas_scsih.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/scsi/mpt2sas/mpt2sas_scsih.c b/drivers/scsi/mpt2sas/mpt2sas_scsih.c index cd89f42440fe..f9ce31950314 100644 --- a/drivers/scsi/mpt2sas/mpt2sas_scsih.c +++ b/drivers/scsi/mpt2sas/mpt2sas_scsih.c @@ -3016,7 +3016,8 @@ _scsih_tm_tr_send(struct MPT2SAS_ADAPTER *ioc, u16 handle) 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 @@ _scsih_tm_tr_send(struct MPT2SAS_ADAPTER *ioc, u16 handle) 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);