We are running kernel 3.7.1 here with dozens of raid1 arrays each composed of a pair of multipath devices (over iscsi). Multipath is configured with no_path_retry (queuing the i/o if the paths all fail) for what amounts to two minutes. When we have any path fail events long enough to surface errors to raid most of the arrays degrade correctly but we often end up with a handful mirrors that are degraded but have a pair of kernel threads stuck in D state with the following stacks: [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 [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 At this point the raid device is completely inaccessible and we are forced to restart the host to restore access. Does this sound like a configuration problem or some kind of deadlock bug with barriers? Thanks for your help, Tregaron Bayly Bluehost, Inc. -- 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
