On 03/07/2012 01:03 AM, Kay Sievers wrote:
On Tue, Mar 6, 2012 at 21:06, Andrew Vagin<avagin@xxxxxxxxxx> wrote:
The queue handling in the udev daemon assumes that the events are
ordered.
Before this patch uevent_seqnum is incremented under sequence_lock,
than an event is send uner uevent_sock_mutex. I want to say that code
contained a window between incrementing seqnum and sending an event.
This patch locks uevent_sock_mutex before incrementing uevent_seqnum.
I think we can remove the spin_lock(&sequence_lock); entirely now, right?
I thought about that too. sequence_lock is used when CONFIG_NET isn't
defined. I've looked on this code one more time and we may leave only
uevent_sock_mutex and use it even when CONFIG_NET isn't defined.
Thanks for the comment.
Greg, do you have other objections about this patch?
Also the section with:
seq = ++uevent_seqnum;
can just be:
add_uevent_var(env, "SEQNUM=%llu", (unsigned long long) ++uevent_seqnum);
right?
And the:
mutex_lock(&uevent_sock_mutex);
can just move outside of the _NET ifdef and we always use the mutex
instead of the spinlock?
That could look much simpler than the current code, I think.
Thanks,
Kay
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