[parted-devel] Possible Race Condition using test code, libparted, and Fedora 12

[Curtis Gedak]

Petr Uzel wrote:
> if this udev change is the cause of the resizing problem, then it is
> different issue from the 'create partition-delete partition-
> partition still in /proc/partitions' issue which I've described
> earlier, because I can reproduce it on system with udev-128.
>   

Hi Petr,

I think that it is still possible that both the resizing problem and the 
"create partition-delete partition-partition still in /proc/partitions" 
might be due to the same root problem.  The change to udev-138 might 
simply have increased the frequency of occurrence of the problem.

With the resizing problem when the "failure to inform kernel of 
partition changes" problem occurs, the entry in /proc/partitions is not 
updated.  Hence it will contain the old size for the partition instead 
of the new size.  This is similar to the problem you found with 
/proc/partitions not being updated (entries not being created or deleted).

If I understand udev properly, it is responsible for creating, deleting, 
and updating devices in the /dev directory and hence /proc/partitions too.

Perhaps you could try your test with the potential patch I posted to see 
if it helps the situation?

My testing of the patch has been running for over 3 days and over 43,000 
iterations.  So far no problems with "failure to inform kernel of 
partition changes" have occurred.  This is the largest number of 
iterations I have been able to run with my test prior to encountering a 
problem with the kernel re-reading the partition table.

I expect it will take at least another 3 or 4 days for the test to reach 
99,999 iterations.  I will report back to this mailing list with the 
results of this test.

Regards,
Curtis Gedak