Cc raid list. On Fri, Jan 15, 2016 at 1:51 AM, Ming Lin <mlin@xxxxxxxxxx> wrote: > On Wed, Jan 13, 2016 at 11:22 PM, Miu Vlad-Cosmin <miuvlad@xxxxxxxxx> wrote: >> Hello, >> >> In a rather basic bcache setup (one cache + mdraid backing), >> I encounter a kernel problem related to bcache with 4.4.0. >> >> In order to trigger this bug, fill the cache with some dirty data. >> When there is some dirty data, wait for the bcache_writeback to >> start writing it to the backing device (0-3 minutes) >> and the BUG triggers. >> >> Please find more info here: https://bugzilla.kernel.org/show_bug.cgi?id=110771 >> >> [<ffffffff815822af>] make_request+0x47f/0xca0 >> [<ffffffff815a5d3d>] md_make_request+0xdd/0x220 >> [<ffffffff810c53ce>] ? pick_next_task_fair+0x12e/0x450 >> [<ffffffff81311d2e>] generic_make_request+0xce/0x1b0 >> [<ffffffff815a1b70>] write_dirty+0x60/0xb0 >> [<ffffffff810aafa7>] process_one_work+0x147/0x3d0 >> [<ffffffff810ab546>] worker_thread+0x46/0x440 >> [<ffffffff810ab500>] ? rescuer_thread+0x2d0/0x2d0 >> [<ffffffff810ab500>] ? rescuer_thread+0x2d0/0x2d0 >> [<ffffffff810afeb4>] kthread+0xc4/0xe0 >> [<ffffffff810afdf0>] ? kthread_park+0x50/0x50 >> [<ffffffff8170c85f>] ret_from_fork+0x3f/0x70 >> >> A bisect shows "[578270bfbd2803dc7b0b03fbc2ac119efbc73195] >> block: fix segment split" as the problem. It is the 2nd time to report this commit as 'regression', and last time it is because bio bounce is after splitting. The commit itself is correct and the report should be false positive, the real bug might be related with bio splitting. > [ 83.436844] BUG: unable to handle kernel NULL pointer dereference at 0000000000000028 > [ 83.437025] IP: [<ffffffff81309ce5>] bio_trim+0x15/0xe0 0028 should be offset of 'bio->bi_iter.bi_size', so looks 'read_bio' from bio_clone_mddev() is NULL? BTW, can some write loading trigger the bug just on raid1 without bcache? Thanks, > > CC Ming Lei. > >> >> Anyone can confirm this ? >> >> Thanks, >> Vlad -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
