scsi: qla2xxx: do not queue commands when unloading

When the driver is unloading, in qla2x00_remove_one(), there is a single
call/point in time to abort ongoing commands, qla2x00_abort_all_cmds(),
which is still several steps away from the call to scsi_remove_host().

If more commands continue to arrive and be processed during that
interval, when the driver is tearing down and releasing its structures,
it might potentially hit an oops due to invalid memory access:

    Unable to handle kernel paging request for data at address 0x00000138
    <...>
    NIP [d000000004700a40] qla2xxx_queuecommand+0x80/0x3f0 [qla2xxx]
    LR [d000000004700a10] qla2xxx_queuecommand+0x50/0x3f0 [qla2xxx]

So, fail commands in qla2xxx_queuecommand() if the UNLOADING bit is set.

Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>
Acked-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 4d99c3b376871c7c38b8f06c852ec69523921af1..e5db474436688739f76842a38ab3351dd1e2133d 100644 (file)
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -707,6 +707,11 @@ qla2xxx_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
        srb_t *sp;
        int rval;
 
+       if (unlikely(test_bit(UNLOADING, &base_vha->dpc_flags))) {
+               cmd->result = DID_NO_CONNECT << 16;
+               goto qc24_fail_command;
+       }
+
        if (ha->flags.eeh_busy) {
                if (ha->flags.pci_channel_io_perm_failure) {
                        ql_dbg(ql_dbg_aer, vha, 0x9010,