Messages in this thread | | | Subject | Re: 回复: 回复: [PATCH] f2fs: fix a ra ce condition between f2fs write end io and f2fs del fsy nc node entry | From | Chao Yu <> | Date | Thu, 18 Jun 2020 15:31:31 +0800 |
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On 2020/6/18 11:28, Zac wrote: >> On 2020/6/18 10:39, Zac wrote: >>> >>>> On 2020/6/17 17:04, zhaowuyun@wingtech.com wrote: >>>>> From: Wuyun Zhao <zhaowuyun@wingtech.com> >>>>> >>>>> Under some condition, the __write_node_page will submit a page which >> is >>>> not >>>>> f2fs_in_warm_node_list and will not call f2fs_add_fsync_node_entry. >>>>> f2fs_gc continue to run to invoke f2fs_iget -> do_read_inode to read > the >>>> same node page >>>>> and set code node, which make f2fs_in_warm_node_list become true, >>>>> that will cause f2fs_bug_on in f2fs_del_fsync_node_entry when >>>> f2fs_write_end_io called. >>>> Could you please add below race condition description into commit >>>> message? >>>> >>>> - f2fs_write_end_io >>>> - f2fs_iget >>>> - do_read_inode >>>> - set_cold_node >>>> recover cold node flag >>>> - f2fs_in_warm_node_list >>>> - is_cold_node >>>> if node is cold, assume we have added >>>> node to fsync_node_list during writepages() >>>> - f2fs_del_fsync_node_entry >>>> - f2fs_bug_on() due to node page >>>> is not in fsync_node_list >>> >>> Ok, will add the commit message. >>> >>>> BTW, I'm curious about why we can lose cold flag for non-dir inode? >>>> any clue to reproduce this bug (I mean losing cold flag)? >>> >>> it's a f2fs image with 25600MB >>> flash this image to device >>> the device will resize it according to the userdata partition size which > is >>> about 94GB >>> the device mount the f2fs partition >>> then hit this f2fs_bug_on >>> >>> seems that the cold flag is not been set when mkfs >> >> Ah, I guess both mkfs/sload ignores setting cold node flag for non-dir > inode, >> could you please send another patch to fix this issue? > > Patch v2 has been sent.
I see, it looks good to me.
Actually, I meant we need to fix mkfs/sload bugs as well, do you have time to work on it? :)
Thanks,
> >>> >>> I think the issue is that >>> >>> 1. the node page in the storage is without cold bit >>> 2. f2fs_disable_checkpoint -> f2fs_gc -> f2fs_get_node_page, this page >> won't >>> be set cold flag >>> 3. f2fs_move_node_page -> __write_node_page to write this page >>> 4. f2fs_gc -> f2fs_iget -> do_read_inode to read this page and set cold > flag >> >> Clear enough, thanks for your explanation. :) >> >> Thanks, >> >>> >>>>> >>>>> [ 34.966133] Call trace: >>>>> [ 34.969902] f2fs_del_fsync_node_entry+0x100/0x108 >>>>> [ 34.976071] f2fs_write_end_io+0x1e0/0x288 >>>>> [ 34.981539] bio_endio+0x248/0x270 >>>>> [ 34.986289] blk_update_request+0x2b0/0x4d8 >>>>> [ 34.991841] scsi_end_request+0x40/0x440 >>>>> [ 34.997126] scsi_io_completion+0xa4/0x748 >>>>> [ 35.002593] scsi_finish_command+0xdc/0x110 >>>>> [ 35.008143] scsi_softirq_done+0x118/0x150 >>>>> [ 35.013610] blk_done_softirq+0x8c/0xe8 >>>>> [ 35.018811] __do_softirq+0x2e8/0x578 >>>>> [ 35.023828] irq_exit+0xfc/0x120 >>>>> [ 35.028398] handle_IPI+0x1d8/0x330 >>>>> [ 35.033233] gic_handle_irq+0x110/0x1d4 >>>>> [ 35.038433] el1_irq+0xb4/0x130 >>>>> [ 35.042917] kmem_cache_alloc+0x3f0/0x418 >>>>> [ 35.048288] radix_tree_node_alloc+0x50/0xf8 >>>>> [ 35.053933] __radix_tree_create+0xf8/0x188 >>>>> [ 35.059484] __radix_tree_insert+0x3c/0x128 >>>>> [ 35.065035] add_gc_inode+0x90/0x118 >>>>> [ 35.069967] f2fs_gc+0x1b80/0x2d70 >>>>> [ 35.074718] f2fs_disable_checkpoint+0x94/0x1d0 >>>>> [ 35.080621] f2fs_fill_super+0x10c4/0x1b88 >>>>> [ 35.086088] mount_bdev+0x194/0x1e0 >>>>> [ 35.090923] f2fs_mount+0x40/0x50 >>>>> [ 35.095589] mount_fs+0xb4/0x190 >>>>> [ 35.100159] vfs_kern_mount+0x80/0x1d8 >>>>> [ 35.105260] do_mount+0x478/0xf18 >>>>> [ 35.109926] ksys_mount+0x90/0xd0 >>>>> [ 35.114592] __arm64_sys_mount+0x24/0x38 >>>>> >>>>> Signed-off-by: Wuyun Zhao <zhaowuyun@wingtech.com> >>>> >>>> Reviewed-by: Chao Yu <yuchao0@huawei.com> >>>> >>>> Thanks, >>>> >>>>> --- >>>>> fs/f2fs/inode.c | 1 + >>>>> 1 file changed, 1 insertion(+) >>>>> >>>>> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c >>>>> index be6ac33..0df5c8c 100644 >>>>> --- a/fs/f2fs/inode.c >>>>> +++ b/fs/f2fs/inode.c >>>>> @@ -402,6 +402,7 @@ static int do_read_inode(struct inode *inode) >>>>> >>>>> /* try to recover cold bit for non-dir inode */ >>>>> if (!S_ISDIR(inode->i_mode) && !is_cold_node(node_page)) { >>>>> + f2fs_wait_on_page_writeback(node_page, NODE, true, true); >>>>> set_cold_node(node_page, false); >>>>> set_page_dirty(node_page); >>>>> } >>>>> >>> >>> . >>> > > . >
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