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From:   Daeho Jeong <daeho43@gmail.com>
Date:   Mon, 31 Aug 2020 15:15:52 +0900
Message-ID: <CACOAw_xpVOaU1-zJXmNSc8kkxhqE5eMZFT0PwWxwNo4XwjRH0g@mail.gmail.com>
Subject: Re: [f2fs-dev] [PATCH] f2fs: prevent compressed file from being
 disabled after releasing cblocks
To:     Chao Yu <yuchao0@huawei.com>
Cc:     Chao Yu <chao@kernel.org>, Daeho Jeong <daehojeong@google.com>,
        kernel-team@android.com, linux-kernel@vger.kernel.org,
        linux-f2fs-devel@lists.sourceforge.net
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I think this patch is enough for now.
If you have anything else we should take care, please let me know~

2020=EB=85=84 8=EC=9B=94 31=EC=9D=BC (=EC=9B=94) =EC=98=A4=ED=9B=84 3:08, C=
hao Yu <yuchao0@huawei.com>=EB=8B=98=EC=9D=B4 =EC=9E=91=EC=84=B1:
>
> On 2020/8/31 11:55, Daeho Jeong wrote:
> >> - open(O_RDWR)
> >> - ioctl(FS_IOC_SETFLAGS, F2FS_COMPR_FL)
> >> - write()
> >> - ioctl(RELEASE_COMPRESS_BLOCKS) -- inode is immutable now
> >> - ioctl(FS_IOC_SETFLAGS, ~F2FS_COMPR_FL) -- Should we allow to update =
immutable inode?
> >> as we know, normally, immutable inode should deny open(O_WRONLY or O_R=
DWR) and later update.
> >>
> >
> > For this case, with this patch we'll return -EINVAL for
> > ioctl(FS_IOC_SETFLAGS, ~F2FS_COMPR_FL).
> > I thought RESERVE_COMPRESS_BLOCKS ioctl is always required to get the
> > file to normal mode after RELEASE_COMPRESS_BLOCKS is called.
>
> That's an example, after compressed block release, shouldn't we disallow =
other ioctl
> interface which updates immutable inode?
>
> > .
> >