Messages in this thread | | | Subject | Re: [PATCH] UBI: Fix possible deadlock in erase_worker() | From | Artem Bityutskiy <> | Date | Wed, 17 Sep 2014 12:35:26 +0300 |
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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?
-- Best Regards, Artem Bityutskiy
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