Re: [2.4 patch] Port of adutux driver from 2.6 kernel to 2.4.

On Tue, 16 Oct 2007 16:54:49 +0300, Vitaliy Ivanov <vitalivanov@xxxxxxxxx> wrote:

Again, comments are welcomed.

It looks like you misunderstood why a static lock protects open counts.
This is done so you do not need to worry about in-structure lock which
can be freed together with the structure. Look at this:

+static int adu_release_internal(struct adu_device *dev)
+{
+ /* lock this device */
+ down(&dev->sem);
+ /* decrement our usage count for the device */
+ --dev->open_count;
+ if (dev->open_count <= 0) {
+ adu_abort_transfers(dev);
+ dev->open_count = 0;
+ }
+ /* unlock this device */
+ up(&dev->sem);

The dev->sem is entirely unnecessary here. Every time you use
open_count, it's protected by minor_table_mutex. The name is a litte
unfortunate, feel free to rename it.

This is probably a problem in 2.6 as well. I don't know why people keep
writing these things. Someone at Ontrak needs to look into it.

-- Pete
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