Add a "bus" symlink to the class and block devices, just like the "driver"
and "device" links. This may be a huge speed gain for e.g. udev to determine
the bus value of a device, as we currently need to do a brute-force scan in
/sys/bus/* to find this value.
/sys
|-- block
| |-- fd0
| | |-- bus -> ../../bus/platform
| | |-- dev
| | |-- device -> ../../devices/platform/floppy0
| | |-- queue
| | | |-- iosched
|-- class
| |-- net
| | |-- eth0
| | | |-- addr_len
| | | |-- address
| | | |-- broadcast
| | | |-- bus -> ../../../bus/pci
| | | |-- carrier
...
| | |-- ttyS0
| | | |-- bus -> ../../../bus/pnp
| | | |-- dev
| | | |-- device -> ../../../devices/pnp0/00:09
| | | `-- driver -> ../../../bus/pnp/drivers/serial
...
| |-- sound
| | |-- controlC0
| | | |-- bus -> ../../../bus/pci
| | | |-- dev
| | | |-- device -> ../../../devices/pci0000:00/0000:00:1f.5
| | | `-- driver -> ../../../bus/pci/drivers/Intel ICH
Signed-off-by: Kay Sievers <[email protected]>
===== drivers/base/class.c 1.58 vs edited =====
--- 1.58/drivers/base/class.c 2005-02-05 19:35:12 +01:00
+++ edited/drivers/base/class.c 2005-02-15 21:31:06 +01:00
@@ -196,33 +196,33 @@ void class_device_remove_bin_file(struct
sysfs_remove_bin_file(&class_dev->kobj, attr);
}
-static int class_device_dev_link(struct class_device * class_dev)
+static void class_device_add_dev_symlinks(struct class_device *class_dev)
{
- if (class_dev->dev)
- return sysfs_create_link(&class_dev->kobj,
- &class_dev->dev->kobj, "device");
- return 0;
-}
+ if (!class_dev->dev)
+ return 0;
-static void class_device_dev_unlink(struct class_device * class_dev)
-{
- sysfs_remove_link(&class_dev->kobj, "device");
-}
+ sysfs_create_link(&class_dev->kobj, &class_dev->dev->kobj, "device");
-static int class_device_driver_link(struct class_device * class_dev)
-{
- if ((class_dev->dev) && (class_dev->dev->driver))
- return sysfs_create_link(&class_dev->kobj,
- &class_dev->dev->driver->kobj, "driver");
- return 0;
+ if (class_dev->dev->driver)
+ sysfs_create_link(&class_dev->kobj,
+ &class_dev->dev->driver->kobj, "driver");
+
+ if (class_dev->dev->bus)
+ sysfs_create_link(&class_dev->kobj,
+ &class_dev->dev->bus->subsys.kset.kobj,
+ "bus");
}
-static void class_device_driver_unlink(struct class_device * class_dev)
+static void class_device_remove_dev_symlinks(struct class_device *class_dev)
{
+ if (!class_dev->dev)
+ return 0;
+
+ sysfs_remove_link(&class_dev->kobj, "device");
sysfs_remove_link(&class_dev->kobj, "driver");
+ sysfs_remove_link(&class_dev->kobj, "bus");
}
-
static ssize_t
class_device_attr_show(struct kobject * kobj, struct attribute * attr,
char * buf)
@@ -452,8 +452,7 @@ int class_device_add(struct class_device
class_device_create_file(class_dev, &class_device_attr_dev);
class_device_add_attrs(class_dev);
- class_device_dev_link(class_dev);
- class_device_driver_link(class_dev);
+ class_device_add_dev_symlinks(class_dev);
register_done:
if (error && parent)
@@ -482,8 +481,7 @@ void class_device_del(struct class_devic
up_write(&parent->subsys.rwsem);
}
- class_device_dev_unlink(class_dev);
- class_device_driver_unlink(class_dev);
+ class_device_remove_dev_symlinks(class_dev);
class_device_remove_attrs(class_dev);
kobject_del(&class_dev->kobj);
===== fs/partitions/check.c 1.129 vs edited =====
--- 1.129/fs/partitions/check.c 2005-01-31 07:33:40 +01:00
+++ edited/fs/partitions/check.c 2005-02-15 21:14:43 +01:00
@@ -318,6 +318,8 @@ static void disk_sysfs_symlinks(struct g
struct device *target = get_device(disk->driverfs_dev);
if (target) {
sysfs_create_link(&disk->kobj,&target->kobj,"device");
+ if (target->bus)
+ sysfs_create_link(&disk->kobj,&target->bus->subsys.kset.kobj,"bus");
sysfs_create_link(&target->kobj,&disk->kobj,"block");
}
}
@@ -438,6 +440,7 @@ void del_gendisk(struct gendisk *disk)
if (disk->driverfs_dev) {
sysfs_remove_link(&disk->kobj, "device");
+ sysfs_remove_link(&disk->kobj, "bus");
sysfs_remove_link(&disk->driverfs_dev->kobj, "block");
put_device(disk->driverfs_dev);
}
On Tue, Feb 15, 2005 at 09:53:44PM +0100, Kay Sievers wrote:
> Add a "bus" symlink to the class and block devices, just like the "driver"
> and "device" links. This may be a huge speed gain for e.g. udev to determine
> the bus value of a device, as we currently need to do a brute-force scan in
> /sys/bus/* to find this value.
Hmm, while playing around with it, I think we should create the "bus"
link on the physical device on not on the class device.
Also the current "driver" link at the class device should be removed,
cause class devices don't have a driver. Block devices never had this
misleading symlink.
>From the class device we point with the "device" link to the physical
device, and only the physical device should have the "driver" and the
"bus" link, as it represents the real relationship.
Signed-off-by: Kay Sievers <[email protected]>
+++ edited/drivers/base/bus.c 2005-02-15 22:33:37 +01:00
@@ -465,6 +465,7 @@ int bus_add_device(struct device * dev)
up_write(&dev->bus->subsys.rwsem);
device_add_attrs(bus, dev);
sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id);
+ sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus");
}
return error;
}
@@ -481,6 +482,7 @@ int bus_add_device(struct device * dev)
void bus_remove_device(struct device * dev)
{
if (dev->bus) {
+ sysfs_remove_link(&dev->kobj, "bus");
sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id);
device_remove_attrs(dev->bus, dev);
down_write(&dev->bus->subsys.rwsem);
===== drivers/base/class.c 1.58 vs edited =====
--- 1.58/drivers/base/class.c 2005-02-05 19:35:12 +01:00
+++ edited/drivers/base/class.c 2005-02-15 22:32:08 +01:00
@@ -196,33 +196,6 @@ void class_device_remove_bin_file(struct
sysfs_remove_bin_file(&class_dev->kobj, attr);
}
-static int class_device_dev_link(struct class_device * class_dev)
-{
- if (class_dev->dev)
- return sysfs_create_link(&class_dev->kobj,
- &class_dev->dev->kobj, "device");
- return 0;
-}
-
-static void class_device_dev_unlink(struct class_device * class_dev)
-{
- sysfs_remove_link(&class_dev->kobj, "device");
-}
-
-static int class_device_driver_link(struct class_device * class_dev)
-{
- if ((class_dev->dev) && (class_dev->dev->driver))
- return sysfs_create_link(&class_dev->kobj,
- &class_dev->dev->driver->kobj, "driver");
- return 0;
-}
-
-static void class_device_driver_unlink(struct class_device * class_dev)
-{
- sysfs_remove_link(&class_dev->kobj, "driver");
-}
-
-
static ssize_t
class_device_attr_show(struct kobject * kobj, struct attribute * attr,
char * buf)
@@ -452,8 +425,9 @@ int class_device_add(struct class_device
class_device_create_file(class_dev, &class_device_attr_dev);
class_device_add_attrs(class_dev);
- class_device_dev_link(class_dev);
- class_device_driver_link(class_dev);
+ if (class_dev->dev)
+ sysfs_create_link(&class_dev->kobj,
+ &class_dev->dev->kobj, "device");
register_done:
if (error && parent)
@@ -482,8 +456,8 @@ void class_device_del(struct class_devic
up_write(&parent->subsys.rwsem);
}
- class_device_dev_unlink(class_dev);
- class_device_driver_unlink(class_dev);
+ if (class_dev->dev)
+ sysfs_remove_link(&class_dev->kobj, "device");
class_device_remove_attrs(class_dev);
kobject_del(&class_dev->kobj);
On Tue, 15 Feb 2005 23:04:06 +0100, Kay Sievers <[email protected]> wrote:
>
> -static int class_device_dev_link(struct class_device * class_dev)
> -{
> - if (class_dev->dev)
> - return sysfs_create_link(&class_dev->kobj,
> - &class_dev->dev->kobj, "device");
> - return 0;
> -}
> -
> -static void class_device_dev_unlink(struct class_device * class_dev)
> -{
> - sysfs_remove_link(&class_dev->kobj, "device");
> -}
> -
Hi,
I can agree on dropping driver link but I think that the link to
underlying real device is still needed.
--
Dmitry
On Tue, Feb 15, 2005 at 05:25:54PM -0500, Dmitry Torokhov wrote:
> On Tue, 15 Feb 2005 23:04:06 +0100, Kay Sievers <[email protected]> wrote:
> >
> > -static int class_device_dev_link(struct class_device * class_dev)
> > -{
> > - if (class_dev->dev)
> > - return sysfs_create_link(&class_dev->kobj,
> > - &class_dev->dev->kobj, "device");
> > - return 0;
> > -}
> > -
> > -static void class_device_dev_unlink(struct class_device * class_dev)
> > -{
> > - sysfs_remove_link(&class_dev->kobj, "device");
> > -}
> > -
>
> Hi,
>
> I can agree on dropping driver link but I think that the link to
> underlying real device is still needed.
It's still there, read the patch :)
thanks,
greg k-h
On Tuesday 15 February 2005 18:44, Greg KH wrote:
> On Tue, Feb 15, 2005 at 05:25:54PM -0500, Dmitry Torokhov wrote:
> > On Tue, 15 Feb 2005 23:04:06 +0100, Kay Sievers <[email protected]> wrote:
> > >
> > > -static int class_device_dev_link(struct class_device * class_dev)
> > > -{
> > > - if (class_dev->dev)
> > > - return sysfs_create_link(&class_dev->kobj,
> > > - &class_dev->dev->kobj, "device");
> > > - return 0;
> > > -}
> > > -
> > > -static void class_device_dev_unlink(struct class_device * class_dev)
> > > -{
> > > - sysfs_remove_link(&class_dev->kobj, "device");
> > > -}
> > > -
> >
> > Hi,
> >
> > I can agree on dropping driver link but I think that the link to
> > underlying real device is still needed.
>
> It's still there, read the patch :)
>
Oops, missed that. Sorry.
--
Dmitry
On Tue, Feb 15, 2005 at 11:04:06PM +0100, Kay Sievers wrote:
> On Tue, Feb 15, 2005 at 09:53:44PM +0100, Kay Sievers wrote:
> > Add a "bus" symlink to the class and block devices, just like the "driver"
> > and "device" links. This may be a huge speed gain for e.g. udev to determine
> > the bus value of a device, as we currently need to do a brute-force scan in
> > /sys/bus/* to find this value.
>
> Hmm, while playing around with it, I think we should create the "bus"
> link on the physical device on not on the class device.
>
> Also the current "driver" link at the class device should be removed,
> cause class devices don't have a driver. Block devices never had this
> misleading symlink.
>
> >From the class device we point with the "device" link to the physical
> device, and only the physical device should have the "driver" and the
> "bus" link, as it represents the real relationship.
Applied, thanks,
greg k-h