[SCSI] libfc: fix referencing to fc_fcp_pkt from the frame pointer via fr_fsp()

In commit 6a716a8, while releasing the DDP context in case frame_send() failed,
the frame may already be freed, so we should store the pointer to fc_fcp_pkt and
release the DDP context using the locally stored fsp instead of getting fsp from
the fr_fsp(fp) on a frame.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Reported-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
index 744fefe..d261e98 100644 (file)
--- a/drivers/scsi/libfc/fc_exch.c
+++ b/drivers/scsi/libfc/fc_exch.c
@@ -1981,6 +1981,7 @@ static struct fc_seq *fc_exch_seq_send(struct fc_lport *lport,
        struct fc_exch *ep;
        struct fc_seq *sp = NULL;
        struct fc_frame_header *fh;
+       struct fc_fcp_pkt *fsp = NULL;
        int rc = 1;
 
        ep = fc_exch_alloc(lport, fp);
@@ -2003,8 +2004,10 @@ static struct fc_seq *fc_exch_seq_send(struct fc_lport *lport,
        fc_exch_setup_hdr(ep, fp, ep->f_ctl);
        sp->cnt++;
 
-       if (ep->xid <= lport->lro_xid && fh->fh_r_ctl == FC_RCTL_DD_UNSOL_CMD)
+       if (ep->xid <= lport->lro_xid && fh->fh_r_ctl == FC_RCTL_DD_UNSOL_CMD) {
+               fsp = fr_fsp(fp);
                fc_fcp_ddp_setup(fr_fsp(fp), ep->xid);
+       }
 
        if (unlikely(lport->tt.frame_send(lport, fp)))
                goto err;
@@ -2018,7 +2021,8 @@ static struct fc_seq *fc_exch_seq_send(struct fc_lport *lport,
        spin_unlock_bh(&ep->ex_lock);
        return sp;
 err:
-       fc_fcp_ddp_done(fr_fsp(fp));
+       if (fsp)
+               fc_fcp_ddp_done(fsp);
        rc = fc_exch_done_locked(ep);
        spin_unlock_bh(&ep->ex_lock);
        if (!rc)