From 315cb0ad124575e75da2d0e0a95990587fc23485 Mon Sep 17 00:00:00 2001 From: James Smart Date: Thu, 7 Aug 2008 20:49:30 -0400 Subject: [PATCH] [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 Signed-off-by: James Bottomley --- drivers/scsi/hosts.c | 2 +- drivers/scsi/scsi_proc.c | 8 ++++---- drivers/scsi/scsi_tgt_lib.c | 6 +++--- drivers/scsi/scsi_transport_iscsi.c | 4 ++-- 4 files changed, 10 insertions(+), 10 deletions(-) diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index fed0b02ebc1..3fdbb13e80a 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -464,7 +464,7 @@ static int __scsi_host_match(struct device *dev, void *data) 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 c6a904a45bf..82f7b2dd08a 100644 --- a/drivers/scsi/scsi_proc.c +++ b/drivers/scsi/scsi_proc.c @@ -259,8 +259,8 @@ static int scsi_add_single_device(uint host, uint channel, uint id, uint lun) 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 @@ static int scsi_remove_single_device(uint host, uint channel, uint id, uint lun) 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 257e097c39a..f26299dfc5d 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; } diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c index 043c3921164..0ce5f7cdfe2 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; -- 2.39.2