[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>
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index fed0b02..3fdbb13 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -464,7 +464,7 @@
struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
{
struct device *cdev;
- struct Scsi_Host *shost = ERR_PTR(-ENXIO);
+ struct Scsi_Host *shost = NULL;
cdev = class_find_device(&shost_class, NULL, &hostnum,
__scsi_host_match);
diff --git a/drivers/scsi/scsi_proc.c b/drivers/scsi/scsi_proc.c
index c6a904a..82f7b2d 100644
--- a/drivers/scsi/scsi_proc.c
+++ b/drivers/scsi/scsi_proc.c
@@ -259,8 +259,8 @@
int error = -ENXIO;
shost = scsi_host_lookup(host);
- if (IS_ERR(shost))
- return PTR_ERR(shost);
+ if (!shost)
+ return error;
if (shost->transportt->user_scan)
error = shost->transportt->user_scan(shost, channel, id, lun);
@@ -287,8 +287,8 @@
int error = -ENXIO;
shost = scsi_host_lookup(host);
- if (IS_ERR(shost))
- return PTR_ERR(shost);
+ if (!shost)
+ return error;
sdev = scsi_device_lookup(shost, channel, id, lun);
if (sdev) {
scsi_remove_device(sdev);
diff --git a/drivers/scsi/scsi_tgt_lib.c b/drivers/scsi/scsi_tgt_lib.c
index 257e097..f26299d 100644
--- a/drivers/scsi/scsi_tgt_lib.c
+++ b/drivers/scsi/scsi_tgt_lib.c
@@ -460,7 +460,7 @@
/* 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 @@
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 @@
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;
}
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 043c392..0ce5f7c 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -1361,7 +1361,7 @@
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 @@
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;
