Messages in this thread | | | From | Rabin Vincent <> | Date | Thu, 19 Jan 2012 01:13:21 +0530 | Subject | Re: [PATCH] mm/backing-dev.c: fix crash when USB/SCSI device is detached |
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On Mon, Jan 16, 2012 at 12:04, Chanho Min <chanho0207@gmail.com> wrote: >> But wait.. Rabin's patch actually fixes the NULL deference in >> the call >> >> trace_writeback_wake_forker_thread(bdi); >> >> The wakeup of the forker thread should be harmless. >> > The forker thread shoud not be woken up after the bdi is unregistered. > Is this also Rabin's intention? > Also, I'm not sure the wakeup of the forker thread is harmless as bellows. > .. > case FORK_THREAD: > .. > task = kthread_create(bdi_writeback_thread, &bdi->wb, > "flush-%s", dev_name(bdi->dev));
By the time the bdi->dev is made NULL, the bdi has been removed from the bdi_list (in bdi_wb_shutdown()), so even if the forker thread is woken up after that it will not find the bdi and won't get to this part of the code. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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