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References: <490be4e0b984e146c93586507442de3dad8694bb.camel@mediatek.com> <20220705085308.32518-1-ed.tsai@mediatek.com>
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From:   Miklos Szeredi <miklos@szeredi.hu>
Date:   Mon, 18 Jul 2022 15:57:17 +0200
Message-ID: <CAJfpegvez_DodKK+CJc1a7EHLDB+4wCSB2ay5NZWUCyoq1_ANw@mail.gmail.com>
Subject: Re: [PATCH 1/1] fuse: add fuse_d_iput to postponed the iput
To:     Ed Tsai <ed.tsai@mediatek.com>
Cc:     linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        fuse-devel <fuse-devel@lists.sourceforge.net>,
        chenguanyou <chenguanyou9338@gmail.com>,
        =?UTF-8?B?U3RhbmxleSBDaHUgKOacseWOn+mZnik=?= 
        <stanley.chu@mediatek.com>,
        =?UTF-8?B?WW9uZy14dWFuIFdhbmcgKOeOi+ipoOiQsSk=?= 
        <Yong-xuan.Wang@mediatek.com>, wsd_upstream@mediatek.com
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On Tue, 5 Jul 2022 at 10:53, Ed Tsai <ed.tsai@mediatek.com> wrote:
>
> When all the references of an inode are dropped, and write of its dirty
> pages is serving in Daemon, reclaim may deadlock on a regular allocation
> in Daemon.
>
> Add fuse_dentry_iput and some FI_* flags to postponed the iput for the
> inodes be using in fuse_write_inode.

I don't understand.

The inode must have a positive refcount during fuse_write_inode(), so
how would delaying an iput() change anything?

Thanks,
Miklos