[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, 3 insertions, 3 deletions

diff --git a/drivers/scsi/scsi_tgt_lib.c b/drivers/scsi/scsi_tgt_lib.c
index 257e097c39af..f26299dfc5d5 100644
--- a/drivers/scsi/scsi_tgt_lib.c
+++ b/drivers/scsi/scsi_tgt_lib.c
@@ -460,7 +460,7 @@ int scsi_tgt_kspace_exec(int host_no, u64 itn_id, int result, u64 tag,
 
 	/* TODO: replace with a O(1) alg */
 	shost = scsi_host_lookup(host_no);
-	if (IS_ERR(shost)) {
+	if (!shost) {
 		printk(KERN_ERR "Could not find host no %d\n", host_no);
 		return -EINVAL;
 	}
@@ -550,7 +550,7 @@ int scsi_tgt_kspace_tsk_mgmt(int host_no, u64 itn_id, u64 mid, int result)
 	dprintk("%d %d %llx\n", host_no, result, (unsigned long long) mid);
 
 	shost = scsi_host_lookup(host_no);
-	if (IS_ERR(shost)) {
+	if (!shost) {
 		printk(KERN_ERR "Could not find host no %d\n", host_no);
 		return err;
 	}
@@ -603,7 +603,7 @@ int scsi_tgt_kspace_it_nexus_rsp(int host_no, u64 itn_id, int result)
 	dprintk("%d %d%llx\n", host_no, result, (unsigned long long)itn_id);
 
 	shost = scsi_host_lookup(host_no);
-	if (IS_ERR(shost)) {
+	if (!shost) {
 		printk(KERN_ERR "Could not find host no %d\n", host_no);
 		return err;
 	}