From: Chao Liu <chaoliu719@gmail.com>
To: Chao Yu <chao@kernel.org>, Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Chao Liu <liuchao@coolpad.com>,
linux-kernel@vger.kernel.org, Wayne Zhang <zhangwen@coolpad.com>,
Yue Hu <huyue2@coolpad.com>,
linux-f2fs-devel@lists.sourceforge.net
Subject: Re: [f2fs-dev] [PATCH] f2fs: fix to remove F2FS_COMPR_FL and tag F2FS_NOCOMP_FL at the same time
Date: Wed, 6 Jul 2022 10:57:48 +0800 [thread overview]
Message-ID: <YsT6LKtTQCuOdPHt@liuchao-VM> (raw)
In-Reply-To: <YrPvuPLze3QoCkPJ@liuchao-VM>
Ping.
On Thu, Jun 23, 2022 at 12:44:40PM +0800, Chao Liu wrote:
> On Wed, Jun 22, 2022 at 09:42:13PM +0800, Chao Yu wrote:
> > On 2022/6/21 14:48, Chao Liu wrote:
> > > From: Chao Liu <liuchao@coolpad.com>
> > >
> > > If the inode has the compress flag, it will fail to use
> > > 'chattr -c +m' to remove its compress flag and tag no compress flag.
> > > However, the same command will be successful when executed again,
> > > as shown below:
> > >
> > > $ touch foo.txt
> > > $ chattr +c foo.txt
> > > $ chattr -c +m foo.txt
> > > chattr: Invalid argument while setting flags on foo.txt
> > > $ chattr -c +m foo.txt
> > > $ f2fs_io getflags foo.txt
> > > get a flag on foo.txt ret=0, flags=nocompression,inline_data
> > >
> > > Fix this by removing some checks in f2fs_setflags_common()
> > > that do not affect the original logic. I go through all the
> > > possible scenarios, and the results are as follows. Bold is
> > > the only thing that has changed.
> > >
> > > +---------------+-----------+-----------+----------+
> > > | | file flags |
> > > + command +-----------+-----------+----------+
> > > | | no flag | compr | nocompr |
> > > +---------------+-----------+-----------+----------+
> > > | chattr +c | compr | compr | -EINVAL |
> > > | chattr -c | no flag | no flag | nocompr |
> > > | chattr +m | nocompr | -EINVAL | nocompr |
> > > | chattr -m | no flag | compr | no flag |
> > > | chattr +c +m | -EINVAL | -EINVAL | -EINVAL |
> > > | chattr +c -m | compr | compr | compr |
> > > | chattr -c +m | nocompr | *nocompr* | nocompr |
> > > | chattr -c -m | no flag | no flag | no flag |
> > > +---------------+-----------+-----------+----------+
> > >
> > > Fixes: 4c8ff7095bef ("f2fs: support data compression")
> > > Signed-off-by: Chao Liu <liuchao@coolpad.com>
> > > ---
> > >
> > > This patch depends on the the patch
> > > "f2fs: allow compression of files without blocks" sent earlier this day.
> > >
> > > fs/f2fs/file.c | 9 +--------
> > > 1 file changed, 1 insertion(+), 8 deletions(-)
> > >
> > > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> > > index daaa0dfd2d2e..0c3ae5993b7a 100644
> > > --- a/fs/f2fs/file.c
> > > +++ b/fs/f2fs/file.c
> > > @@ -1873,10 +1873,7 @@ static int f2fs_setflags_common(struct inode *inode, u32 iflags, u32 mask)
> > > if (masked_flags & F2FS_COMPR_FL) {
> > > if (!f2fs_disable_compressed_file(inode))
> > > return -EINVAL;
> > > - }
> > > - if (iflags & F2FS_NOCOMP_FL)
> > > - return -EINVAL;
> > > - if (iflags & F2FS_COMPR_FL) {
> > > + } else {
> > > if (!f2fs_may_compress(inode))
> > > return -EINVAL;
> > > if (S_ISREG(inode->i_mode) && F2FS_HAS_BLOCKS(inode))
> > > @@ -1885,10 +1882,6 @@ static int f2fs_setflags_common(struct inode *inode, u32 iflags, u32 mask)
> > > set_compress_context(inode);
> > > }
> > > }
> > > - if ((iflags ^ masked_flags) & F2FS_NOCOMP_FL) {
> > > - if (masked_flags & F2FS_COMPR_FL)
> > > - return -EINVAL;
> > > - }
> >
> > Without above check condition, can we return -EINVAL for the case:
> >
> > chattr +c on file w/ nocompr flag
> >
> > | | no flag | compr | nocompr |
> > +---------------+-----------+-----------+----------+
> > | chattr +c | compr | compr | *-EINVAL* |
>
> Yes, we can.
>
> chattr(1) grabs flags via GETFLAGS, modifies the result,
> and passes that to SETFLAGS. If we execute 'chattr +c'
> on the file with nocompr flag, the iflags will
> contain both compr and nocompr flags, then be refused by:
>
> if ((iflags & F2FS_COMPR_FL) && (iflags & F2FS_NOCOMP_FL))
> return -EINVAL;
>
> In addition, if iflags has only compr flag, while masked_flags
> has only nocompr flag for some reason
> (either because of concurrency of chattr(1) or by a user),
> I think we need remove nocompr flag and tag compr flag on the file,
> similar to the following.
>
> | | no flag | compr | nocompr |
> +---------------+-----------+-----------+----------+
> | chattr +c -m | compr | compr | *compr* |
>
> Thanks,
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next prev parent reply other threads:[~2022-07-06 2:58 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-21 6:48 [f2fs-dev] [PATCH] f2fs: fix to remove F2FS_COMPR_FL and tag F2FS_NOCOMP_FL at the same time Chao Liu
2022-06-22 13:42 ` Chao Yu
2022-06-23 4:44 ` Chao Liu
2022-07-06 2:57 ` Chao Liu [this message]
2022-07-06 14:21 ` Chao Yu
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