[SCSI] be2iscsi: Fix possible reentrancy issue in be_iopoll

The driver creates "NAPI" context per core which is fine,
however the above routine declares the ret variable as static!
Thus there is only one instance of this variable!
When this routine is called from more than one thread of execution,
than the result is unpredictable.

         static unsigned int ret;
         .....

         ret = beiscsi_process_cq(pbe_eq);
                 <--------Another thread can enter here and change "ret".
         if (ret < budget) {
                ....
         }
                 <--------Another thread can enter here and change "ret".
         return ret;

Fix - remove the "static"

Signed-off-by: Shlomo Pongratz <shlomop@mellanox.com>
Signed-off-by: Jayamohan Kallickal <jayamohan.kallickal@emulex.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

diff --git a/drivers/scsi/be2iscsi/be_main.c b/drivers/scsi/be2iscsi/be_main.c
index 228d331..fe30e3f 100644 (file)
--- a/drivers/scsi/be2iscsi/be_main.c
+++ b/drivers/scsi/be2iscsi/be_main.c
@@ -2191,7 +2191,7 @@ void beiscsi_process_all_cqs(struct work_struct *work)
 
 static int be_iopoll(struct blk_iopoll *iop, int budget)
 {
-       static unsigned int ret;
+       unsigned int ret;
        struct beiscsi_hba *phba;
        struct be_eq_obj *pbe_eq;