On Wed, 13 Jul 2016, Stefan Priebe - Profihost AG wrote: > > Am 13.07.2016 um 08:18 schrieb Eric Wheeler: > > On Mon, 11 Jul 2016, Eric Wheeler wrote: > > > >> On Tue, 5 Jul 2016, Jackie Tea wrote: > >> > >>> I've been using bcache on a Xen host (sitting on an LVM partition) for > >>> many months without problems > >>> > >>> Now that I added DRBD on top of bcache, bcache locks up within a few > >>> hours, giving me this message: > >> > >> This might be related to the thread to this thread: > >> > >> https://lkml.org/lkml/2016/6/22/172 > >> and this patch: > >> https://patchwork.kernel.org/patch/9223697/ > >> > >> Notably, this bug was introduced in 4.3 and newer. You might try 4.1 and > >> see if your problem resolves itself, or 4.8 is supposed to fix this too if > >> the patch gets in. > > > > Make sure you have these patches, too. Looking at your stack, you > > definitely want "A", maybe the others as well: > > > > A. [PATCH v2] block: make sure big bio is splitted into at most 256 bvecs > > by Ming Lei: https://patchwork.kernel.org/patch/9169483/ > > > > B. block: don't make BLK_DEF_MAX_SECTORS too big > > by Shaohua Li: http://www.spinics.net/lists/linux-bcache/msg03525.html > > > > C. [1/3] block: flush queued bios when process blocks to avoid deadlock > > by Mikulas Patocka: https://patchwork.kernel.org/patch/9204125/ > > > > D. dm-crypt: Fix error with too large bios > > by Mikulas Patocka: https://patchwork.kernel.org/patch/9138595/ > > > > E. block: fix blk_queue_split() resource exhaustion > > by Lars Ellenberg: https://patchwork.kernel.org/patch/9223697/ > > (as above, previous post. > > > > Just want to let you now that here is stated that this does not always > fix C also a backport to 4.4 and others is currently missing: > https://bugzilla.kernel.org/show_bug.cgi?id=119841 Interesting, so Mikulas' "C" with threading/timer is fixing things that Lars' "E" did not? Well, here's hoping for a good fix. There are a lot of great developers working on this. More detail here: https://www.redhat.com/archives/dm-devel/2016-June/msg00425.html -- Eric Wheeler > > Stefan > > > You probably don't need "D" for your setup by looking at lsblk. > > > > [ "C" excluded on purpose because "E" supersedes it, but here it is if > > you'd like to try. Note that "E" and "C" are mutually exclusive: > > > > C. [1/3] block: flush queued bios when process blocks to avoid deadlock > > by Mikulas Patocka: https://patchwork.kernel.org/patch/9204125/ > > (was https://patchwork.kernel.org/patch/7398411/) > > ] > > > > Please try and let us know which (if any of these) fix your issue! > > > > -Eric > > > > > > > > -- > > Eric Wheeler > > > > > >> > >> > >> > >>> > >>> Jul 5 04:06:43 dom0 kernel: [23043.136864] INFO: task > >>> bcache_writebac:1342 blocked for more than 120 seconds. > >>> Jul 5 04:06:43 dom0 kernel: [23043.136896] Not tainted > >>> 4.4.0-28-generic #47-Ubuntu > >>> Jul 5 04:06:43 dom0 kernel: [23043.136916] "echo 0 > > >>> /proc/sys/kernel/hung_task_timeout_secs" disables this message. > >>> Jul 5 04:06:43 dom0 kernel: [23043.136946] bcache_writebac D > >>> ffff880000983d18 0 1342 2 0x00000000 > >>> Jul 5 04:06:43 dom0 kernel: [23043.136952] ffff880000983d18 > >>> 0000000000007ff0 ffffffff81e11500 ffff880035705780 > >>> Jul 5 04:06:43 dom0 kernel: [23043.136955] ffff880000984000 > >>> ffff880005080af0 ffff880005080ad8 ffffffff00000000 > >>> Jul 5 04:06:43 dom0 kernel: [23043.136958] ffffffff00000003 > >>> ffff880000983d30 ffffffff818235b5 ffff880035705780 > >>> Jul 5 04:06:43 dom0 kernel: [23043.136962] Call Trace: > >>> Jul 5 04:06:43 dom0 kernel: [23043.136971] [<ffffffff818235b5>] > >>> schedule+0x35/0x80 > >>> Jul 5 04:06:43 dom0 kernel: [23043.136974] [<ffffffff81826202>] > >>> rwsem_down_write_failed+0x202/0x350 > >>> Jul 5 04:06:43 dom0 kernel: [23043.136990] [<ffffffffc015e6d0>] ? > >>> read_dirty+0x370/0x370 [bcache] > >>> Jul 5 04:06:43 dom0 kernel: [23043.136995] [<ffffffff813f9643>] > >>> call_rwsem_down_write_failed+0x13/0x20 > >>> Jul 5 04:06:43 dom0 kernel: [23043.136999] [<ffffffff81825a3d>] ? > >>> down_write+0x2d/0x40 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137009] [<ffffffffc015e72b>] > >>> bch_writeback_thread+0x5b/0x4c0 [bcache] > >>> Jul 5 04:06:43 dom0 kernel: [23043.137020] [<ffffffffc015e6d0>] ? > >>> read_dirty+0x370/0x370 [bcache] > >>> Jul 5 04:06:43 dom0 kernel: [23043.137024] [<ffffffff810a0808>] > >>> kthread+0xd8/0xf0 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137027] [<ffffffff810a0730>] ? > >>> kthread_create_on_node+0x1e0/0x1e0 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137029] [<ffffffff81827a4f>] > >>> ret_from_fork+0x3f/0x70 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137032] [<ffffffff810a0730>] ? > >>> kthread_create_on_node+0x1e0/0x1e0 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137043] INFO: task > >>> blkback.5.hda:3357 blocked for more than 120 seconds. > >>> Jul 5 04:06:43 dom0 kernel: [23043.137069] Not tainted > >>> 4.4.0-28-generic #47-Ubuntu > >>> Jul 5 04:06:43 dom0 kernel: [23043.137090] "echo 0 > > >>> /proc/sys/kernel/hung_task_timeout_secs" disables this message. > >>> Jul 5 04:06:43 dom0 kernel: [23043.137119] blkback.5.hda D > >>> ffff88002341ba48 0 3357 2 0x00000000 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137122] ffff88002341ba48 > >>> ffff88002341ba08 ffffffff81e11500 ffff880034189900 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137124] ffff88002341c000 > >>> ffff880005080ad8 ffff880005080af0 ffff880023e08e60 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137126] ffff880005080000 > >>> ffff88002341ba60 ffffffff818235b5 ffff880034189900 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137128] Call Trace: > >>> Jul 5 04:06:43 dom0 kernel: [23043.137131] [<ffffffff818235b5>] > >>> schedule+0x35/0x80 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137133] [<ffffffff81826430>] > >>> rwsem_down_read_failed+0xe0/0x140 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137136] [<ffffffff811903e5>] ? > >>> mempool_alloc_slab+0x15/0x20 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137138] [<ffffffff813f9614>] > >>> call_rwsem_down_read_failed+0x14/0x30 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137140] [<ffffffff81825a00>] ? > >>> down_read+0x20/0x30 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137148] [<ffffffffc01522a2>] > >>> cached_dev_make_request+0x682/0xcc0 [bcache] > >>> Jul 5 04:06:43 dom0 kernel: [23043.137151] [<ffffffff813bba52>] > >>> generic_make_request+0xf2/0x1d0 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137153] [<ffffffff813bbba6>] > >>> submit_bio+0x76/0x170 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137157] [<ffffffffc04ebbb7>] > >>> dispatch_rw_block_io+0x7b7/0xab0 [xen_blkback] > >>> Jul 5 04:06:43 dom0 kernel: [23043.137159] [<ffffffff8101d204>] ? > >>> xen_load_sp0+0x84/0x180 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137162] [<ffffffff810ca961>] ? > >>> __raw_callee_save___pv_queued_spin_unlock+0x11/0x20 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137165] [<ffffffffc04ec245>] > >>> __do_block_io_op+0x395/0x710 [xen_blkback] > >>> Jul 5 04:06:43 dom0 kernel: [23043.137167] [<ffffffff810ec8a8>] ? > >>> del_timer_sync+0x48/0x50 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137170] [<ffffffffc04eca7d>] > >>> xen_blkif_schedule+0xdd/0x7b0 [xen_blkback] > >>> Jul 5 04:06:43 dom0 kernel: [23043.137172] [<ffffffff810a975d>] ? > >>> finish_task_switch+0x7d/0x220 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137175] [<ffffffff810c3ca0>] ? > >>> wake_atomic_t_function+0x60/0x60 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137177] [<ffffffffc04ec9a0>] ? > >>> xen_blkif_be_int+0x30/0x30 [xen_blkback] > >>> Jul 5 04:06:43 dom0 kernel: [23043.137179] [<ffffffff810a0808>] > >>> kthread+0xd8/0xf0 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137181] [<ffffffff810a0730>] ? > >>> kthread_create_on_node+0x1e0/0x1e0 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137183] [<ffffffff81827a4f>] > >>> ret_from_fork+0x3f/0x70 > >>> Jul 5 04:06:43 dom0 kernel: [23043.137185] [<ffffffff810a0730>] ? > >>> kthread_create_on_node+0x1e0/0x1e0 > >>> > >>> At the same time (but always after bcache), Xen's blkback will also > >>> give a similar message: > >>> > >>> Jul 5 04:08:43 dom0 kernel: [23163.135027] INFO: task > >>> bcache_writebac:1342 blocked for more than 120 seconds. > >>> Jul 5 04:08:43 dom0 kernel: [23163.135056] Not tainted > >>> 4.4.0-28-generic #47-Ubuntu > >>> Jul 5 04:08:43 dom0 kernel: [23163.135076] "echo 0 > > >>> /proc/sys/kernel/hung_task_timeout_secs" disables this message. > >>> Jul 5 04:08:43 dom0 kernel: [23163.135105] bcache_writebac D > >>> ffff880000983d18 0 1342 2 0x00000000 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135109] ffff880000983d18 > >>> 0000000000007ff0 ffffffff81e11500 ffff880035705780 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135112] ffff880000984000 > >>> ffff880005080af0 ffff880005080ad8 ffffffff00000000 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135114] ffffffff00000003 > >>> ffff880000983d30 ffffffff818235b5 ffff880035705780 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135116] Call Trace: > >>> Jul 5 04:08:43 dom0 kernel: [23163.135124] [<ffffffff818235b5>] > >>> schedule+0x35/0x80 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135127] [<ffffffff81826202>] > >>> rwsem_down_write_failed+0x202/0x350 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135139] [<ffffffffc015e6d0>] ? > >>> read_dirty+0x370/0x370 [bcache] > >>> Jul 5 04:08:43 dom0 kernel: [23163.135143] [<ffffffff813f9643>] > >>> call_rwsem_down_write_failed+0x13/0x20 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135145] [<ffffffff81825a3d>] ? > >>> down_write+0x2d/0x40 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135153] [<ffffffffc015e72b>] > >>> bch_writeback_thread+0x5b/0x4c0 [bcache] > >>> Jul 5 04:08:43 dom0 kernel: [23163.135160] [<ffffffffc015e6d0>] ? > >>> read_dirty+0x370/0x370 [bcache] > >>> Jul 5 04:08:43 dom0 kernel: [23163.135162] [<ffffffff810a0808>] > >>> kthread+0xd8/0xf0 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135164] [<ffffffff810a0730>] ? > >>> kthread_create_on_node+0x1e0/0x1e0 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135166] [<ffffffff81827a4f>] > >>> ret_from_fork+0x3f/0x70 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135168] [<ffffffff810a0730>] ? > >>> kthread_create_on_node+0x1e0/0x1e0 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135178] INFO: task > >>> blkback.5.hda:3357 blocked for more than 120 seconds. > >>> Jul 5 04:08:43 dom0 kernel: [23163.135204] Not tainted > >>> 4.4.0-28-generic #47-Ubuntu > >>> Jul 5 04:08:43 dom0 kernel: [23163.135224] "echo 0 > > >>> /proc/sys/kernel/hung_task_timeout_secs" disables this message. > >>> Jul 5 04:08:43 dom0 kernel: [23163.135286] blkback.5.hda D > >>> ffff88002341ba48 0 3357 2 0x00000000 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135289] ffff88002341ba48 > >>> ffff88002341ba08 ffffffff81e11500 ffff880034189900 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135291] ffff88002341c000 > >>> ffff880005080ad8 ffff880005080af0 ffff880023e08e60 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135293] ffff880005080000 > >>> ffff88002341ba60 ffffffff818235b5 ffff880034189900 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135295] Call Trace: > >>> Jul 5 04:08:43 dom0 kernel: [23163.135299] [<ffffffff818235b5>] > >>> schedule+0x35/0x80 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135301] [<ffffffff81826430>] > >>> rwsem_down_read_failed+0xe0/0x140 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135304] [<ffffffff811903e5>] ? > >>> mempool_alloc_slab+0x15/0x20 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135307] [<ffffffff813f9614>] > >>> call_rwsem_down_read_failed+0x14/0x30 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135309] [<ffffffff81825a00>] ? > >>> down_read+0x20/0x30 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135316] [<ffffffffc01522a2>] > >>> cached_dev_make_request+0x682/0xcc0 [bcache] > >>> Jul 5 04:08:43 dom0 kernel: [23163.135319] [<ffffffff813bba52>] > >>> generic_make_request+0xf2/0x1d0 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135321] [<ffffffff813bbba6>] > >>> submit_bio+0x76/0x170 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135326] [<ffffffffc04ebbb7>] > >>> dispatch_rw_block_io+0x7b7/0xab0 [xen_blkback] > >>> Jul 5 04:08:43 dom0 kernel: [23163.135328] [<ffffffff8101d204>] ? > >>> xen_load_sp0+0x84/0x180 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135331] [<ffffffff810ca961>] ? > >>> __raw_callee_save___pv_queued_spin_unlock+0x11/0x20 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135334] [<ffffffffc04ec245>] > >>> __do_block_io_op+0x395/0x710 [xen_blkback] > >>> Jul 5 04:08:43 dom0 kernel: [23163.135337] [<ffffffff810ec8a8>] ? > >>> del_timer_sync+0x48/0x50 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135340] [<ffffffffc04eca7d>] > >>> xen_blkif_schedule+0xdd/0x7b0 [xen_blkback] > >>> Jul 5 04:08:43 dom0 kernel: [23163.135343] [<ffffffff810a975d>] ? > >>> finish_task_switch+0x7d/0x220 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135346] [<ffffffff810c3ca0>] ? > >>> wake_atomic_t_function+0x60/0x60 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135348] [<ffffffffc04ec9a0>] ? > >>> xen_blkif_be_int+0x30/0x30 [xen_blkback] > >>> Jul 5 04:08:43 dom0 kernel: [23163.135350] [<ffffffff810a0808>] > >>> kthread+0xd8/0xf0 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135352] [<ffffffff810a0730>] ? > >>> kthread_create_on_node+0x1e0/0x1e0 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135354] [<ffffffff81827a4f>] > >>> ret_from_fork+0x3f/0x70 > >>> Jul 5 04:08:43 dom0 kernel: [23163.135356] [<ffffffff810a0730>] ? > >>> kthread_create_on_node+0x1e0/0x1e0 > >>> > >>> Access to the storage is no longer possible, then (it'll just appear to hang). > >>> This is on the newest Ubuntu 16.04 LTS, with their 4.4.0-28 kernel. > >>> > >>> # lsb_release -d > >>> Description: Ubuntu 16.04 LTS > >>> # uname -r > >>> 4.4.0-28-generic > >>> > >>> bcache is set to writeback. > >>> > >>> # cat /sys/block/bcache0/bcache/cache_mode > >>> writethrough [writeback] writearound none > >>> # cat /sys/block/bcache0/bcache/state > >>> dirty > >>> # cat /sys/block/bcache0/bcache/dirty_data > >>> 56.0k > >>> > >>> The relevant disk stack looks like this: > >>> > >>> # lsblk > >>> sdd 8:48 0 232.9G 0 disk > >>> `-sdd1 8:49 0 232.9G 0 part > >>> `-md1 9:1 0 232.8G 0 raid1 > >>> `-ssd-bcache--back 252:4 0 30G 0 lvm > >>> `-bcache0 251:0 0 2T 0 disk > >>> `-storage-drback--test 252:6 0 200G 0 lvm > >>> > >>> storage-drback--test is the backing device for DRBD. > >>> > >>> This is reproducible, but I do not know what causes it, or how to > >>> cause it on purpose. All I know is that once I put DRBD on top of > >>> bcache, and produce minor load over time (I just have a single idle > >>> Windows 2012R2 server on it as test - as Windows would always do > >>> *something* ;-) it will lock up within 8 hours. > >>> > >>> Do you have any clues as to what could be causing this? > >>> -- > >>> To unsubscribe from this list: send the line "unsubscribe linux-bcache" in > >>> the body of a message to majordomo@xxxxxxxxxxxxxxx > >>> More majordomo info at http://vger.kernel.org/majordomo-info.html > >>> > >> -- > >> To unsubscribe from this list: send the line "unsubscribe linux-bcache" in > >> the body of a message to majordomo@xxxxxxxxxxxxxxx > >> More majordomo info at http://vger.kernel.org/majordomo-info.html > >> > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-bcache" in > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
