[SCSI] scsi_host_lookup: error returns and NULL pointers

This patch cleans up the behavior of scsi_host_lookup().

The original implementation attempted to use the dual role of
either returning a pointer value, or a negative error code.
User's needed to use IS_ERR() to check the result. Additionally,
the IS_ERR() macro never checks for when a NULL pointer was
returned, so a NULL pointer actually passes with a success case.
Note: scsi_host_get(), used by scsi_host_lookup(), can return
a NULL pointer.

Talk about a mudhole for the unitiated to step into....

This patch converts scsi_host_lookup() to return either NULL
or a valid pointer. The consumers were updated for the change.

Signed-off-by: James Smart <james.smart@emulex.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 043c3921164f..0ce5f7cdfe2a 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -1361,7 +1361,7 @@ iscsi_tgt_dscvr(struct iscsi_transport *transport,
 		return -EINVAL;
 
 	shost = scsi_host_lookup(ev->u.tgt_dscvr.host_no);
-	if (IS_ERR(shost)) {
+	if (!shost) {
 		printk(KERN_ERR "target discovery could not find host no %u\n",
 		       ev->u.tgt_dscvr.host_no);
 		return -ENODEV;
@@ -1387,7 +1387,7 @@ iscsi_set_host_param(struct iscsi_transport *transport,
 		return -ENOSYS;
 
 	shost = scsi_host_lookup(ev->u.set_host_param.host_no);
-	if (IS_ERR(shost)) {
+	if (!shost) {
 		printk(KERN_ERR "set_host_param could not find host no %u\n",
 		       ev->u.set_host_param.host_no);
 		return -ENODEV;