From: Miao Xie <miaox@cn.fujitsu.com>
To: Chris Mason <clm@fb.com>
Cc: <linux-btrfs@vger.kernel.org>
Subject: Re: [PATCH v3 10/11] Btrfs: fix possible deadlock caused by pending I/O in plug list
Date: Tue, 2 Dec 2014 21:02:09 +0800 [thread overview]
Message-ID: <547DB851.8020905@cn.fujitsu.com> (raw)
In-Reply-To: <1417210323.6046.3@mail.thefacebook.com>
hi, Chris
On Fri, 28 Nov 2014 16:32:03 -0500, Chris Mason wrote:
> On Wed, Nov 26, 2014 at 10:00 PM, Miao Xie <miaox@cn.fujitsu.com> wrote:
>> On Thu, 27 Nov 2014 09:39:56 +0800, Miao Xie wrote:
>>> On Wed, 26 Nov 2014 10:02:23 -0500, Chris Mason wrote:
>>>> On Wed, Nov 26, 2014 at 8:04 AM, Miao Xie <miaox@cn.fujitsu.com> wrote:
>>>>> The increase/decrease of bio counter is on the I/O path, so we should
>>>>> use io_schedule() instead of schedule(), or the deadlock might be
>>>>> triggered by the pending I/O in the plug list. io_schedule() can help
>>>>> us because it will flush all the pending I/O before the task is going
>>>>> to sleep.
>>>>
>>>> Can you please describe this deadlock in more detail? schedule() also triggers
>>>> a flush of the plug list, and if that's no longer sufficient we can run into other
>>>> problems (especially with preemption on).
>>>
>>> Sorry for my miss. I forgot to check the current implementation of schedule(), which flushes the plug list unconditionally. Please ignore this patch.
>>
>> I have updated my raid56-scrub-replace branch, please re-pull the branch.
>>
>> https://github.com/miaoxie/linux-btrfs.git raid56-scrub-replace
>
> Sorry, I wasn't clear. I do like the patch because it uses a slightly better trigger mechanism for the flush. I was just worried about a larger deadlock.
>
> I ran the raid56 work with stress.sh overnight, then scrubbed the resulting filesystem and ran balance when the scrub completed. All of these passed without errors (excellent!).
>
> Then I zero'd 4GB of one drive and ran scrub again. This was the result. Please make sure CONFIG_DEBUG_PAGEALLOC is enabled and you should be able to reproduce.
I sent out the 4th version of the patchset, please try it.
I have pushed the new patchset to my git tree, you can re-pull it.
https://github.com/miaoxie/linux-btrfs.git raid56-scrub-replace
Thanks
Miao
>
> [192392.495260] BUG: unable to handle kernel paging request at ffff880303062f80
> [192392.495279] IP: [<ffffffffa05fe77a>] lock_stripe_add+0xba/0x390 [btrfs]
> [192392.495281] PGD 2bdb067 PUD 107e7fd067 PMD 107e7e4067 PTE 8000000303062060
> [192392.495283] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
> [192392.495307] Modules linked in: ipmi_devintf loop fuse k10temp coretemp hwmon btrfs raid6_pq zlib_deflate lzo_compress xor xfs exportfs libcrc32c tcp_diag inet_diag nfsv4 ip6table_filter ip6_tables xt_NFLOG nfnetlink_log nfnetlink xt_comment xt_statistic iptable_filter ip_tables x_tables mptctl netconsole autofs4 nfsv3 nfs lockd grace rpcsec_gss_krb5 auth_rpcgss oid_registry sunrpc ipv6 ext3 jbd dm_mod rtc_cmos ipmi_si ipmi_msghandler iTCO_wdt iTCO_vendor_support pcspkr i2c_i801 lpc_ich mfd_core shpchp ehci_pci ehci_hcd mlx4_en ptp pps_core mlx4_core sg ses enclosure button megaraid_sas
> [192392.495310] CPU: 0 PID: 11992 Comm: kworker/u65:2 Not tainted 3.18.0-rc6-mason+ #7
> [192392.495310] Hardware name: ZTSYSTEMS Echo Ridge T4 /A9DRPF-10D, BIOS 1.07 05/10/2012
> [192392.495323] Workqueue: btrfs-btrfs-scrub btrfs_scrub_helper [btrfs]
> [192392.495324] task: ffff88013dae9110 ti: ffff8802296a0000 task.ti: ffff8802296a0000
> [192392.495335] RIP: 0010:[<ffffffffa05fe77a>] [<ffffffffa05fe77a>] lock_stripe_add+0xba/0x390 [btrfs]
> [192392.495335] RSP: 0018:ffff8802296a3ac8 EFLAGS: 00010006
> [192392.495336] RAX: ffff880577e85018 RBX: ffff880497f0b2f8 RCX: ffff8801190fb000
> [192392.495337] RDX: 000000000000013d RSI: ffff880303062f80 RDI: 0000040c275a0000
> [192392.495338] RBP: ffff8802296a3b48 R08: ffff880497f00000 R09: 0000000000000001
> [192392.495339] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000282
> [192392.495339] R13: 000000000000b250 R14: ffff880577e85000 R15: ffff880497f0b2a0
> [192392.495340] FS: 0000000000000000(0000) GS:ffff88085fc00000(0000) knlGS:0000000000000000
> [192392.495341] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [192392.495342] CR2: ffff880303062f80 CR3: 0000000005289000 CR4: 00000000000407f0
> [192392.495342] Stack:
> [192392.495344] ffff880755e28000 ffff880497f00000 000000000000013d ffff8801190fb000
> [192392.495346] 0000000000000000 ffff88013dae9110 ffffffff81090d40 ffff8802296a3b00
> [192392.495347] ffff8802296a3b00 0000000000000010 ffff8802296a3b68 ffff8801190fb000
> [192392.495348] Call Trace:
> [192392.495353] [<ffffffff81090d40>] ? bit_waitqueue+0xa0/0xa0
> [192392.495363] [<ffffffffa05fea66>] raid56_parity_submit_scrub_rbio+0x16/0x30 [btrfs]
> [192392.495372] [<ffffffffa05e2f0e>] scrub_parity_check_and_repair+0x15e/0x1e0 [btrfs]
> [192392.495380] [<ffffffffa05e301d>] scrub_block_put+0x8d/0x90 [btrfs]
> [192392.495388] [<ffffffffa05e6ed7>] ? scrub_bio_end_io_worker+0xd7/0x870 [btrfs]
> [192392.495396] [<ffffffffa05e6ee9>] scrub_bio_end_io_worker+0xe9/0x870 [btrfs]
> [192392.495405] [<ffffffffa05b8c44>] normal_work_helper+0x84/0x330 [btrfs]
> [192392.495414] [<ffffffffa05b8f42>] btrfs_scrub_helper+0x12/0x20 [btrfs]
> [192392.495417] [<ffffffff8106c50f>] process_one_work+0x1bf/0x520
> [192392.495419] [<ffffffff8106c48d>] ? process_one_work+0x13d/0x520
> [192392.495421] [<ffffffff8106c98e>] worker_thread+0x11e/0x4b0
> [192392.495424] [<ffffffff81653ac9>] ? __schedule+0x389/0x880
> [192392.495426] [<ffffffff8106c870>] ? process_one_work+0x520/0x520
> [192392.495428] [<ffffffff81071e2e>] kthread+0xde/0x100
> [192392.495430] [<ffffffff81071d50>] ? __init_kthread_worker+0x70/0x70
> [192392.495431] [<ffffffff81659eac>] ret_from_fork+0x7c/0xb0
> [192392.495433] [<ffffffff81071d50>] ? __init_kthread_worker+0x70/0x70
> [192392.495449] Code: 45 88 49 89 c4 4f 8d 7c 28 50 4b 8b 44 28 50 48 8b 55 90 4c 8d 70 e8 4c 39 f8 48 8b 4d 98 74 32 48 8b 71 10 48 8b 3e 48 8b 70 f8 <48> 39 3e 75 12 eb 6f 0f 1f 80 00 00 00 00 48 8b 76 f8 48 39 3e
> [192392.495458] RIP [<ffffffffa05fe77a>] lock_stripe_add+0xba/0x390 [btrfs]
> [192392.495458] RSP <ffff8802296a3ac8>
> [192392.495458] CR2: ffff880303062f80
> [192392.496389] ---[ end trace c04c23ee0d843df0 ]---
>
>
>
> .
>
next prev parent reply other threads:[~2014-12-02 13:00 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-14 13:50 [PATCH 0/9] Implement device scrub/replace for RAID56 Miao Xie
2014-11-14 13:50 ` [PATCH 1/9] Btrfs: remove noused bbio_ret in __btrfs_map_block in condition Miao Xie
2014-11-14 14:57 ` David Sterba
2014-11-14 13:50 ` [PATCH 2/9] Btrfs: remove unnecessary code of stripe_index assignment in __btrfs_map_block Miao Xie
2014-11-14 14:55 ` David Sterba
2014-11-14 13:50 ` [PATCH 3/9] Btrfs, raid56: don't change bbio and raid_map Miao Xie
2014-11-14 13:50 ` [PATCH 4/9] Btrfs, scrub: repair the common data on RAID5/6 if it is corrupted Miao Xie
2014-11-24 9:31 ` [PATCH v2 " Miao Xie
2014-11-14 13:50 ` [PATCH 5/9] Btrfs,raid56: use a variant to record the operation type Miao Xie
2014-11-14 13:50 ` [PATCH 6/9] Btrfs,raid56: support parity scrub on raid56 Miao Xie
2014-11-14 13:50 ` [PATCH 7/9] Btrfs, replace: write dirty pages into the replace target device Miao Xie
2014-11-14 13:51 ` [PATCH 8/9] Btrfs, replace: write raid56 parity " Miao Xie
2014-11-14 13:51 ` [PATCH 9/9] Btrfs, replace: enable dev-replace for raid56 Miao Xie
2014-11-14 14:28 ` [PATCH 0/9] Implement device scrub/replace for RAID56 Chris Mason
2014-11-25 15:14 ` Chris Mason
2014-11-26 13:04 ` [PATCH v3 00/11] " Miao Xie
2014-11-26 13:04 ` [PATCH v3 01/11] Btrfs: remove noused bbio_ret in __btrfs_map_block in condition Miao Xie
2014-11-26 13:04 ` [PATCH v3 02/11] Btrfs: remove unnecessary code of stripe_index assignment in __btrfs_map_block Miao Xie
2014-11-26 13:04 ` [PATCH v3 03/11] Btrfs, raid56: don't change bbio and raid_map Miao Xie
2014-11-26 13:04 ` [PATCH v3 04/11] Btrfs, scrub: repair the common data on RAID5/6 if it is corrupted Miao Xie
2014-11-26 13:04 ` [PATCH v3 05/11] Btrfs, raid56: use a variant to record the operation type Miao Xie
2014-11-26 13:04 ` [PATCH v3 06/11] Btrfs, raid56: support parity scrub on raid56 Miao Xie
2014-11-26 13:04 ` [PATCH v3 07/11] Btrfs, replace: write dirty pages into the replace target device Miao Xie
2014-11-26 13:04 ` [PATCH v3 08/11] Btrfs, replace: write raid56 parity " Miao Xie
2014-11-26 13:04 ` [PATCH v3 09/11] Btrfs, raid56: fix use-after-free problem in the final device replace procedure on raid56 Miao Xie
2014-11-26 13:04 ` [PATCH v3 10/11] Btrfs: fix possible deadlock caused by pending I/O in plug list Miao Xie
2014-11-26 15:02 ` Chris Mason
2014-11-27 1:39 ` Miao Xie
2014-11-27 3:00 ` Miao Xie
2014-11-28 21:32 ` Chris Mason
2014-12-02 13:02 ` Miao Xie [this message]
2014-11-26 13:04 ` [PATCH v3 11/11] Btrfs, replace: enable dev-replace for raid56 Miao Xie
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