Am 17.09.2014 11:35, schrieb Artem Bityutskiy:
> On Tue, 2014-09-16 at 09:48 +0200, Richard Weinberger wrote:
>> If sync_erase() failes with EINTR, ENOMEM, EAGAIN or
>> EBUSY erase_worker() re-schedules the failed work.
>> This will lead to a deadlock because erase_worker() is called
>> with work_sem held in read mode. And schedule_erase() will take
>> this lock again.
>
> There is this code snippet:
>
> ubi_err("failed to erase PEB %d, error %d", pnum, err);
> kfree(wl_wrk);
>
> if (err == -EINTR || err == -ENOMEM || err == -EAGAIN ||
> err == -EBUSY) {
> int err1;
>
> /* Re-schedule the LEB for erasure */
> err1 = schedule_erase(ubi, e, vol_id, lnum, 0);
> if (err1) {
> err = err1;
> goto out_ro;
> }
> return err;
> }
>
> How about move 'kfree(wl_wrk)' down, and execute
>
> __schedule_ubi_work(ubi, wl_wrk)
>
> inside the 'if' clause instead? The fix would seem to be more elegant
> then.
>
> Hmm?
Yes, that would work too.
Or we apply "[PATCH 1/2] UBI: Call worker functions without work_sem held". :)
Thanks,
//richard
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