[PATCH] Illustration of warning explosion silliness

Jeff Garzik
2006-09-28T00:58:32Z

The following patch (DO NOT APPLY) illustrates why
device_for_each_child() should not be marked with __must_check.

The function returns the return value of the actor function, and ceases
iteration upon error.

However, _every_ case in drivers/scsi has a hardcoded return value,
illustrating how it is quite valid to not check the return value of this
function.

Not-signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index d6743b9..4816c42 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2166,11 +2166,13 @@ target_block(struct device *dev, void *d
void
scsi_target_block(struct device *dev)
{
+ int dummy;
+
if (scsi_is_target_device(dev))
starget_for_each_device(to_scsi_target(dev), NULL,
device_block);
else
- device_for_each_child(dev, NULL, target_block);
+ dummy = device_for_each_child(dev, NULL, target_block);
}
EXPORT_SYMBOL_GPL(scsi_target_block);

@@ -2192,11 +2194,13 @@ target_unblock(struct device *dev, void
void
scsi_target_unblock(struct device *dev)
{
+ int dummy;
+
if (scsi_is_target_device(dev))
starget_for_each_device(to_scsi_target(dev), NULL,
device_unblock);
else
- device_for_each_child(dev, NULL, target_unblock);
+ dummy = device_for_each_child(dev, NULL, target_unblock);
}
EXPORT_SYMBOL_GPL(scsi_target_unblock);

diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index e7fe565..520ec13 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -803,6 +803,7 @@ static int __remove_child (struct device
void scsi_remove_target(struct device *dev)
{
struct device *rdev;
+ int dummy;

if (scsi_is_target_device(dev)) {
__scsi_remove_target(to_scsi_target(dev));
@@ -810,7 +811,7 @@ void scsi_remove_target(struct device *d
}

rdev = get_device(dev);
- device_for_each_child(dev, NULL, __remove_child);
+ dummy = device_for_each_child(dev, NULL, __remove_child);
put_device(rdev);
}
EXPORT_SYMBOL(scsi_remove_target);
diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c
index b5b0c2c..4370244 100644
--- a/drivers/scsi/scsi_transport_sas.c
+++ b/drivers/scsi/scsi_transport_sas.c
@@ -211,8 +211,10 @@ static int do_sas_phy_delete(struct devi
*/
void sas_remove_children(struct device *dev)
{
- device_for_each_child(dev, (void *)0, do_sas_phy_delete);
- device_for_each_child(dev, (void *)1, do_sas_phy_delete);
+ int dummy;
+
+ dummy = device_for_each_child(dev, (void *)0, do_sas_phy_delete);
+ dummy = device_for_each_child(dev, (void *)1, do_sas_phy_delete);
}
EXPORT_SYMBOL(sas_remove_children);

diff --git a/drivers/scsi/scsi_transport_spi.c b/drivers/scsi/scsi_transport_spi.c
index 9f070f0..6cc79e5 100644
--- a/drivers/scsi/scsi_transport_spi.c
+++ b/drivers/scsi/scsi_transport_spi.c
@@ -372,8 +372,9 @@ static ssize_t
store_spi_revalidate(struct class_device *cdev, const char *buf, size_t count)
{
struct scsi_target *starget = transport_class_to_starget(cdev);
+ int dummy;

- device_for_each_child(&starget->dev, NULL, child_iter);
+ dummy = device_for_each_child(&starget->dev, NULL, child_iter);
return count;
}
static CLASS_DEVICE_ATTR(revalidate, S_IWUSR, NULL, store_spi_revalidate);