Hi all, For improving the I/O performance, we try to enable the raid 5 skip_copy feature by default. It indeed has some benefit, however, it will always (not a random issue) dump the following call trace repeatedly when we try to write the raid 5 block device. It is related to the following codes in handle_stripe_clean_event() in raid5.c. WARN_ON(test_bit(R5_SkipCopy, &dev->flags)); WARN_ON(dev->page != dev->orig_page); Is it a known bug for skip_copy feature? Does it do harm to the data integrity? If we would like to prevent this call trace, for your suggestion how should we do to modify the source code? Thanks. <4>[38795.430821] ------------[ cut here ]------------ <4>[38795.430822] WARNING: CPU: 1 PID: 28674 at drivers/md/raid5.c:3447 handle_stripe_clean_event+0x379/0x3d0() <4>[38795.430823] Modules linked in: ppp_deflate bsd_comp ppp_mppe ppp_async ppp_generic crc_ccitt slhc xt_mark ipt_MASQUERADE iptable_nat nf_nat_masquerade_ipv4 nf_nat_ipv4 nf_nat tun iscsi_tcp(O) libiscsi_tcp(O) libiscsi(O) scsi_transport_iscsi(O) iscsi_target_mod target_core_file target_core_iblock target_core_mod fbdisk(O) bonding bridge stp uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core snd_usb_caiaq snd_usb_audio snd_usbmidi_lib snd_seq_midi snd_rawmidi fnotify(PO) udf isofs iTCO_wdt psnap llc tbs_keys(O) dm_c2f(O) ufsd(PO) jnl(O) pl2303 usbserial intel_ips drbd(O) flashcache(O) dm_thin_pool dm_bio_prison dm_persistent_data hal_netlink(O) coretemp mlx4_en(O) mlx4_core(O) mlx_compat(O) ixgbe mdio igb e1000e(O) mpt3sas mpt2sas scsi_transport_sas raid_class uas usb_storage xhci_pci xhci_hcd usblp uhci_hcd ehci_pci ehci_hcd <4>[38795.430839] CPU: 1 PID: 28674 Comm: md2_resync Tainted: P W O 3.19.8 #1 <4>[38795.430840] Hardware name: INSYDE QV96/Type2 - Board Product Name1, BIOS QV96IR23 10/21/2015 <4>[38795.430840] ffffffff81ab550a ffff88009510f9c8 ffffffff81362987 ffff88009510fa08 <4>[38795.430841] ffffffff8105447b ffff88009510fa68 ffff88009897b000 0000000000000000 <4>[38795.430843] ffff8807d742fe48 ffff8807d742fe40 ffff8807d742f800 ffff88009510fa18 <4>[38795.430844] Call Trace: <4>[38795.430845] [<ffffffff81362987>] dump_stack+0x57/0x80 <4>[38795.430847] [<ffffffff8105447b>] warn_slowpath_common+0x8b/0xd0 <4>[38795.430848] [<ffffffff810544d5>] warn_slowpath_null+0x15/0x20 <4>[38795.430850] [<ffffffff8160a829>] handle_stripe_clean_event+0x379/0x3d0 <4>[38795.430851] [<ffffffff8160e2d2>] handle_stripe+0xe52/0x1b50 <4>[38795.430852] [<ffffffff816100af>] sync_request+0x5af/0xbf0 <4>[38795.430853] [<ffffffff810a0a4e>] ? try_to_del_timer_sync+0x4e/0x60 <4>[38795.430854] [<ffffffff810a0a9d>] ? del_timer_sync+0x3d/0x50 <4>[38795.430855] [<ffffffff818938a5>] ? schedule_timeout+0xf5/0x160 <4>[38795.430856] [<ffffffff810a0ab0>] ? del_timer_sync+0x50/0x50 <4>[38795.430858] [<ffffffff8161be39>] md_do_sync+0x9c9/0xf00 <4>[38795.430860] [<ffffffff810856c0>] ? woken_wake_function+0x10/0x10 <4>[38795.430861] [<ffffffff81890fe0>] ? __schedule+0x320/0x860 <4>[38795.430862] [<ffffffff81075d9d>] ? try_to_wake_up+0xed/0x290 <4>[38795.430864] [<ffffffff81619175>] md_thread+0x75/0x120 <4>[38795.430865] [<ffffffff81619100>] ? errors_store+0x70/0x70 <4>[38795.430866] [<ffffffff81619100>] ? errors_store+0x70/0x70 <4>[38795.430867] [<ffffffff8106d87e>] kthread+0xde/0xf0 <4>[38795.430869] [<ffffffff8106d7a0>] ? kthreadd+0x150/0x150 <4>[38795.430870] [<ffffffff818946c8>] ret_from_fork+0x58/0x90 <4>[38795.430871] [<ffffffff8106d7a0>] ? kthreadd+0x150/0x150 <4>[38795.430872] ---[ end trace 9d400a29547fb473 ]--- <4>[38795.430872] ------------[ cut here ]------------ <4>[38795.430874] WARNING: CPU: 1 PID: 28674 at drivers/md/raid5.c:3448 handle_stripe_clean_event+0x1f2/0x3d0() <4>[38795.430874] Modules linked in: ppp_deflate bsd_comp ppp_mppe ppp_async ppp_generic crc_ccitt slhc xt_mark ipt_MASQUERADE iptable_nat nf_nat_masquerade_ipv4 nf_nat_ipv4 nf_nat tun iscsi_tcp(O) libiscsi_tcp(O) libiscsi(O) scsi_transport_iscsi(O) iscsi_target_mod target_core_file target_core_iblock target_core_mod fbdisk(O) bonding bridge stp uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core snd_usb_caiaq snd_usb_audio snd_usbmidi_lib snd_seq_midi snd_rawmidi fnotify(PO) udf isofs iTCO_wdt psnap llc tbs_keys(O) dm_c2f(O) ufsd(PO) jnl(O) pl2303 usbserial intel_ips drbd(O) flashcache(O) dm_thin_pool dm_bio_prison dm_persistent_data hal_netlink(O) coretemp mlx4_en(O) mlx4_core(O) mlx_compat(O) ixgbe mdio igb e1000e(O) mpt3sas mpt2sas scsi_transport_sas raid_class uas usb_storage xhci_pci xhci_hcd usblp uhci_hcd ehci_pci ehci_hcd <4>[38795.430891] CPU: 1 PID: 28674 Comm: md2_resync Tainted: P W O 3.19.8 #1 <4>[38795.430891] Hardware name: INSYDE QV96/Type2 - Board Product Name1, BIOS QV96IR23 10/21/2015 <4>[38795.430892] ffffffff81ab550a ffff88009510f9c8 ffffffff81362987 ffff88009510fa08 <4>[38795.430893] ffffffff8105447b ffff88009510fa68 ffff88009897b000 0000000000000000 <4>[38795.430894] ffff8807d742fe48 ffff8807d742fe40 ffff8807d742f800 ffff88009510fa18 <4>[38795.430895] Call Trace: <4>[38795.430897] [<ffffffff81362987>] dump_stack+0x57/0x80 <4>[38795.430898] [<ffffffff8105447b>] warn_slowpath_common+0x8b/0xd0 <4>[38795.430899] [<ffffffff810544d5>] warn_slowpath_null+0x15/0x20 <4>[38795.430901] [<ffffffff8160a6a2>] handle_stripe_clean_event+0x1f2/0x3d0 <4>[38795.430902] [<ffffffff8160e2d2>] handle_stripe+0xe52/0x1b50 <4>[38795.430903] [<ffffffff816100af>] sync_request+0x5af/0xbf0 <4>[38795.430904] [<ffffffff810a0a4e>] ? try_to_del_timer_sync+0x4e/0x60 <4>[38795.430906] [<ffffffff810a0a9d>] ? del_timer_sync+0x3d/0x50 <4>[38795.430907] [<ffffffff818938a5>] ? schedule_timeout+0xf5/0x160 <4>[38795.430908] [<ffffffff810a0ab0>] ? del_timer_sync+0x50/0x50 <4>[38795.430909] [<ffffffff8161be39>] md_do_sync+0x9c9/0xf00 <4>[38795.430911] [<ffffffff810856c0>] ? woken_wake_function+0x10/0x10 <4>[38795.430912] [<ffffffff81890fe0>] ? __schedule+0x320/0x860 <4>[38795.430914] [<ffffffff81075d9d>] ? try_to_wake_up+0xed/0x290 <4>[38795.430915] [<ffffffff81619175>] md_thread+0x75/0x120 <4>[38795.430916] [<ffffffff81619100>] ? errors_store+0x70/0x70 <4>[38795.430918] [<ffffffff81619100>] ? errors_store+0x70/0x70 <4>[38795.430919] [<ffffffff8106d87e>] kthread+0xde/0xf0 <4>[38795.430920] [<ffffffff8106d7a0>] ? kthreadd+0x150/0x150 <4>[38795.430921] [<ffffffff818946c8>] ret_from_fork+0x58/0x90 <4>[38795.430922] [<ffffffff8106d7a0>] ? kthreadd+0x150/0x150 <4>[38795.430923] ---[ end trace 9d400a29547fb474 ]--- -- 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
