So, this looks suspicious to me: > [flush-9:16] > [<ffffffffa009f1a4>] wait_barrier+0x124/0x180 [raid1] > [<ffffffffa00a2a15>] make_request+0x85/0xd50 [raid1] > [<ffffffff813653c3>] md_make_request+0xd3/0x200 > [<ffffffff811f494a>] generic_make_request+0xca/0x100 > [<ffffffff811f49f9>] submit_bio+0x79/0x160 > [<ffffffff811808f8>] submit_bh+0x128/0x200 > [<ffffffff81182fe0>] __block_write_full_page+0x1d0/0x330 > [<ffffffff8118320e>] block_write_full_page_endio+0xce/0x100 > [<ffffffff81183255>] block_write_full_page+0x15/0x20 > [<ffffffff81187908>] blkdev_writepage+0x18/0x20 > [<ffffffff810f73b7>] __writepage+0x17/0x40 > [<ffffffff810f8543>] write_cache_pages+0x1d3/0x4c0 > [<ffffffff810f8881>] generic_writepages+0x51/0x80 > [<ffffffff810f88d0>] do_writepages+0x20/0x40 > [<ffffffff811782bb>] __writeback_single_inode+0x3b/0x160 > [<ffffffff8117a8a9>] writeback_sb_inodes+0x1e9/0x430 > [<ffffffff8117ab8e>] __writeback_inodes_wb+0x9e/0xd0 > [<ffffffff8117ae9b>] wb_writeback+0x24b/0x2e0 > [<ffffffff8117b171>] wb_do_writeback+0x241/0x250 > [<ffffffff8117b222>] bdi_writeback_thread+0xa2/0x250 > [<ffffffff8106414e>] kthread+0xce/0xe0 > [<ffffffff81488a6c>] ret_from_fork+0x7c/0xb0 > [<ffffffffffffffff>] 0xffffffffffffffff Thread [flush-9:16] is in wait_barrier(), which executes this: wait_event_lock_irq(conf->wait_barrier, !conf->barrier || (conf->nr_pending && current->bio_list && !bio_list_empty(current->bio_list)), conf->resync_lock, ); > [md16-raid1] > [<ffffffffa009ffb9>] handle_read_error+0x119/0x790 [raid1] > [<ffffffffa00a0862>] raid1d+0x232/0x1060 [raid1] > [<ffffffff813675a7>] md_thread+0x117/0x150 > [<ffffffff8106414e>] kthread+0xce/0xe0 > [<ffffffff81488a6c>] ret_from_fork+0x7c/0xb0 > [<ffffffffffffffff>] 0xffffffffffffffff and thread [md16-raid1] is in handle_read_error(), which calls freeze_array(), which executes this: wait_event_lock_irq(conf->wait_barrier, conf->nr_pending == conf->nr_queued+1, conf->resync_lock, flush_pending_writes(conf)); ...different conditions, but the same wait queue and lock. Both threads are TASK_UNINTERRUPTIBLE, which would be consistent with both of them being in the wait_event_lock_irq(). This seems more and more like a deadlock to me, but kernel concurrency is beyond my skill. Do these symptoms and stack look like a race/deadlock to anyone else? Tregaron Bayly -- 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