Signed-off-by: Jeff Garzik <[email protected]>
---
drivers/pnp/card.c | 30 +++++++++++++++++++++---------
drivers/pnp/interface.c | 17 ++++++++++++++---
2 files changed, 35 insertions(+), 12 deletions(-)
diff --git a/drivers/pnp/card.c b/drivers/pnp/card.c
index 227600c..91c047a 100644
--- a/drivers/pnp/card.c
+++ b/drivers/pnp/card.c
@@ -164,9 +164,17 @@ static DEVICE_ATTR(card_id,S_IRUGO,pnp_s
static int pnp_interface_attach_card(struct pnp_card *card)
{
- device_create_file(&card->dev,&dev_attr_name);
- device_create_file(&card->dev,&dev_attr_card_id);
+ int rc = device_create_file(&card->dev,&dev_attr_name);
+ if (rc) return rc;
+
+ rc = device_create_file(&card->dev,&dev_attr_card_id);
+ if (rc) goto err_name;
+
return 0;
+
+err_name:
+ device_remove_file(&card->dev,&dev_attr_name);
+ return rc;
}
/**
@@ -306,16 +314,20 @@ found:
down_write(&dev->dev.bus->subsys.rwsem);
dev->card_link = clink;
dev->dev.driver = &drv->link.driver;
- if (pnp_bus_type.probe(&dev->dev)) {
- dev->dev.driver = NULL;
- dev->card_link = NULL;
- up_write(&dev->dev.bus->subsys.rwsem);
- return NULL;
- }
- device_bind_driver(&dev->dev);
+ if (pnp_bus_type.probe(&dev->dev))
+ goto err_out;
+ if (device_bind_driver(&dev->dev))
+ goto err_out;
+
up_write(&dev->dev.bus->subsys.rwsem);
return dev;
+
+err_out:
+ dev->dev.driver = NULL;
+ dev->card_link = NULL;
+ up_write(&dev->dev.bus->subsys.rwsem);
+ return NULL;
}
/**
diff --git a/drivers/pnp/interface.c b/drivers/pnp/interface.c
index 9d8b415..ac9fcd4 100644
--- a/drivers/pnp/interface.c
+++ b/drivers/pnp/interface.c
@@ -461,8 +461,19 @@ static DEVICE_ATTR(id,S_IRUGO,pnp_show_c
int pnp_interface_attach_device(struct pnp_dev *dev)
{
- device_create_file(&dev->dev,&dev_attr_options);
- device_create_file(&dev->dev,&dev_attr_resources);
- device_create_file(&dev->dev,&dev_attr_id);
+ int rc = device_create_file(&dev->dev,&dev_attr_options);
+ if (rc) goto err;
+ rc = device_create_file(&dev->dev,&dev_attr_resources);
+ if (rc) goto err_opt;
+ rc = device_create_file(&dev->dev,&dev_attr_id);
+ if (rc) goto err_res;
+
return 0;
+
+err_res:
+ device_remove_file(&dev->dev,&dev_attr_resources);
+err_opt:
+ device_remove_file(&dev->dev,&dev_attr_options);
+err:
+ return rc;
}
On Wed, 11 Oct 2006 17:51:09 -0400
Jeff Garzik <[email protected]> wrote:
> + int rc = device_create_file(&dev->dev,&dev_attr_options);
> + if (rc) goto err;
> + rc = device_create_file(&dev->dev,&dev_attr_resources);
> + if (rc) goto err_opt;
> + rc = device_create_file(&dev->dev,&dev_attr_id);
> + if (rc) goto err_res;
> +
> return 0;
> +
> +err_res:
> + device_remove_file(&dev->dev,&dev_attr_resources);
> +err_opt:
> + device_remove_file(&dev->dev,&dev_attr_options);
> +err:
> + return rc;
That's a common pattern, isn't it?
I wonder if we could create some sort of automatic-unwinding engine:
int pnp_interface_attach_device(struct pnp_dev *dev)
{
struct unwind_engine *u = NULL;
int err;
u = UNWINDABLE(u, err, device_create_file(&dev->dev,&dev_attr_options),
device_remove_file, &dev->dev, &dev_attr_options);
u = UNWINDABLE(u, err, device_create_file(&dev->dev,&dev_attr_id)
device_remove_file, &dev->dev, &dev_attr_options);
u = UNWINDABLE(u, err, device_create_file(&dev->dev,&dev_attr_id),
device_remove_file, &dev->dev, &dev_attr_id);
err = unwind(err, u);
return err;
}
and, umm,
#define UNWINDABLE(u, err, expr, undo_fn, arg1, arg2)
if (err == 0) {
err = (expr);
if (err == 0)
u = add_unwind(u, undo_fn, arg1, arg2);
}
u;
int unwind(int err, struct unwind_engine *u)
{
if (err == 0)
return 0;
for (all entries in u in opposite order) {
u->fn(u->arg0, u>arg1);
kfree(u);
}
return err;
}
I dunno - probably too crappy to live, but it'd encourage/help people to
dtrt.
On Wednesday 11 October 2006 18:45, Andrew Morton wrote:
> On Wed, 11 Oct 2006 17:51:09 -0400
> Jeff Garzik <[email protected]> wrote:
>
> > + int rc = device_create_file(&dev->dev,&dev_attr_options);
> > + if (rc) goto err;
> > + rc = device_create_file(&dev->dev,&dev_attr_resources);
> > + if (rc) goto err_opt;
> > + rc = device_create_file(&dev->dev,&dev_attr_id);
> > + if (rc) goto err_res;
> > +
> > return 0;
> > +
> > +err_res:
> > + device_remove_file(&dev->dev,&dev_attr_resources);
> > +err_opt:
> > + device_remove_file(&dev->dev,&dev_attr_options);
> > +err:
> > + return rc;
>
> That's a common pattern, isn't it?
>
> I wonder if we could create some sort of automatic-unwinding engine:
>
> int pnp_interface_attach_device(struct pnp_dev *dev)
> {
> struct unwind_engine *u = NULL;
> int err;
>
> u = UNWINDABLE(u, err, device_create_file(&dev->dev,&dev_attr_options),
> device_remove_file, &dev->dev, &dev_attr_options);
> u = UNWINDABLE(u, err, device_create_file(&dev->dev,&dev_attr_id)
> device_remove_file, &dev->dev, &dev_attr_options);
> u = UNWINDABLE(u, err, device_create_file(&dev->dev,&dev_attr_id),
> device_remove_file, &dev->dev, &dev_attr_id);
> err = unwind(err, u);
> return err;
> }
>
> and, umm,
>
> #define UNWINDABLE(u, err, expr, undo_fn, arg1, arg2)
> if (err == 0) {
> err = (expr);
> if (err == 0)
> u = add_unwind(u, undo_fn, arg1, arg2);
> }
> u;
>
> int unwind(int err, struct unwind_engine *u)
> {
> if (err == 0)
> return 0;
> for (all entries in u in opposite order) {
> u->fn(u->arg0, u>arg1);
> kfree(u);
> }
> return err;
> }
>
>
> I dunno - probably too crappy to live, but it'd encourage/help people to
> dtrt.
The best solution is to switch drivers with more than 2 attributes
to use arribute groups which collapses unwinding nicely.
--
Dmitry