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Subject: Re: [f2fs-dev] [PATCH] f2fs: protect new segment allocation in
 expand_inode_data
To:     Daeho Jeong <daeho43@gmail.com>, <linux-kernel@vger.kernel.org>,
        <linux-f2fs-devel@lists.sourceforge.net>, <kernel-team@android.com>
CC:     Daeho Jeong <daehojeong@google.com>
References: <20200527040231.70891-1-daeho43@gmail.com>
From:   Chao Yu <yuchao0@huawei.com>
Message-ID: <e2ecd025-96aa-7f9d-49f7-a821ea18f9dd@huawei.com>
Date:   Thu, 28 May 2020 10:17:41 +0800
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On 2020/5/27 12:02, Daeho Jeong wrote:
> From: Daeho Jeong <daehojeong@google.com>
> 
> Found a new segemnt allocation without f2fs_lock_op() in
> expand_inode_data(). So, when we do fallocate() for a pinned file
> and trigger checkpoint very frequently and simultaneously. F2FS gets
> stuck in the below code of do_checkpoint() forever.
> 
>   f2fs_sync_meta_pages(sbi, META, LONG_MAX, FS_CP_META_IO);
>   /* Wait for all dirty meta pages to be submitted for IO */
>                                                 <= if fallocate() here,
>   f2fs_wait_on_all_pages(sbi, F2FS_DIRTY_META); <= it'll wait forever.
> 
> Signed-off-by: Daeho Jeong <daehojeong@google.com>

Reviewed-by: Chao Yu <yuchao0@huawei.com>

Thanks,