Date:   Tue, 7 Feb 2023 10:46:34 -0800
From:   Jaegeuk Kim <jaegeuk@kernel.org>
To:     Chao Yu <chao@kernel.org>
Cc:     Yangtao Li <frank.li@vivo.com>,
        linux-f2fs-devel@lists.sourceforge.net,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 1/3] f2fs: fix to set ipu policy
Message-ID: <Y+KcivkBV6rep3R0@google.com>
References: <20230206144310.2344-1-frank.li@vivo.com>
 <5b47f58a-4c3c-a183-777c-d4750f6b4d6c@kernel.org>
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On 02/07, Chao Yu wrote:
> On 2023/2/6 22:43, Yangtao Li wrote:
> > For LFS mode, it should update outplace and no need inplace update.
> > When using LFS mode for small-volume devices, IPU will not be used,
> > and the OPU writing method is actually used, but F2FS_IPU_FORCE can
> > be read from the ipu_policy node, which is different from the actual
> > situation. And remount to lfs mode should be disallowed when
> > f2fs ipu is enabled, let's fix it.
> > 
> > Fixes: 84b89e5d943d ("f2fs: add auto tuning for small devices")
> > Signed-off-by: Yangtao Li <frank.li@vivo.com>
> > ---
> > v4:
> > -allow set 0 in lfs mode for ipu_policy node
> >   fs/f2fs/segment.h | 10 +++++++++-
> >   fs/f2fs/super.c   | 17 +++++++++++------
> >   fs/f2fs/sysfs.c   |  9 +++++++++
> >   3 files changed, 29 insertions(+), 7 deletions(-)
> > 
> > diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
> > index 0f3f05cb8c29..8ee5e5db9287 100644
> > --- a/fs/f2fs/segment.h
> > +++ b/fs/f2fs/segment.h
> > @@ -670,6 +670,8 @@ static inline int utilization(struct f2fs_sb_info *sbi)
> >   #define SMALL_VOLUME_SEGMENTS	(16 * 512)	/* 16GB */
> > +#define F2FS_IPU_DISABLE	0
> > +
> >   enum {
> >   	F2FS_IPU_FORCE,
> >   	F2FS_IPU_SSR,
> > @@ -679,10 +681,16 @@ enum {
> >   	F2FS_IPU_ASYNC,
> >   	F2FS_IPU_NOCACHE,
> >   	F2FS_IPU_HONOR_OPU_WRITE,
> > +	F2FS_IPU_MAX,
> >   };
> > +static inline bool IS_F2FS_IPU_DISABLE(struct f2fs_sb_info *sbi)
> > +{
> > +	return SM_I(sbi)->ipu_policy == F2FS_IPU_DISABLE;
> > +}
> > +
> >   #define F2FS_IPU_POLICY(name)					\
> > -static inline int IS_##name(struct f2fs_sb_info *sbi)		\
> > +static inline bool IS_##name(struct f2fs_sb_info *sbi)		\
> >   {								\
> >   	return SM_I(sbi)->ipu_policy & BIT(name);		\
> >   }
> > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> > index 4ec2cbbc47eb..09696fc844ab 100644
> > --- a/fs/f2fs/super.c
> > +++ b/fs/f2fs/super.c
> > @@ -1346,12 +1346,12 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
> >   	}
> >   	if (test_opt(sbi, DISABLE_CHECKPOINT) && f2fs_lfs_mode(sbi)) {
> > -		f2fs_err(sbi, "LFS not compatible with checkpoint=disable");
> > +		f2fs_err(sbi, "LFS is not compatible with checkpoint=disable");
> >   		return -EINVAL;
> >   	}
> >   	if (test_opt(sbi, ATGC) && f2fs_lfs_mode(sbi)) {
> > -		f2fs_err(sbi, "LFS not compatible with ATGC");
> > +		f2fs_err(sbi, "LFS is not compatible with ATGC");
> >   		return -EINVAL;
> >   	}
> > @@ -2304,6 +2304,12 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
> >   		}
> >   	}
> >   #endif
> > +	if (f2fs_lfs_mode(sbi) && !IS_F2FS_IPU_DISABLE(sbi)) {
> > +		err = -EINVAL;
> > +		f2fs_warn(sbi, "LFS is not compatible with IPU");
> > +		goto restore_opts;
> > +	}
> > +
> >   	/* disallow enable atgc dynamically */
> >   	if (no_atgc == !!test_opt(sbi, ATGC)) {
> >   		err = -EINVAL;
> > @@ -4083,10 +4089,9 @@ static void f2fs_tuning_parameters(struct f2fs_sb_info *sbi)
> >   	/* adjust parameters according to the volume size */
> >   	if (MAIN_SEGS(sbi) <= SMALL_VOLUME_SEGMENTS) {
> >   		if (f2fs_block_unit_discard(sbi))
> > -			SM_I(sbi)->dcc_info->discard_granularity =
> > -						MIN_DISCARD_GRANULARITY;
> > -		SM_I(sbi)->ipu_policy = BIT(F2FS_IPU_FORCE) |
> > -					BIT(F2FS_IPU_HONOR_OPU_WRITE);
> > +			SM_I(sbi)->dcc_info->discard_granularity = MIN_DISCARD_GRANULARITY;
> > +		if (!f2fs_lfs_mode(sbi))
> > +			SM_I(sbi)->ipu_policy = BIT(F2FS_IPU_FORCE) | BIT(F2FS_IPU_HONOR_OPU_WRITE);
> 
> 	SM_I(sbi)->ipu_policy = BIT(F2FS_IPU_FORCE) |
> 				BIT(F2FS_IPU_HONOR_OPU_WRITE);
> 
> I prefer to not exceed 80 lines, otherwise it looks good to me.

Applied.

> 
> Reviewed-by: Chao Yu <chao@kernel.org>
> 
> Thanks,
> 
> >   	}
> >   	sbi->readdir_ra = true;
> > diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
> > index 575a5536c0e7..3c3dae3ce84e 100644
> > --- a/fs/f2fs/sysfs.c
> > +++ b/fs/f2fs/sysfs.c
> > @@ -706,6 +706,15 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
> >   		return count;
> >   	}
> > +	if (!strcmp(a->attr.name, "ipu_policy")) {
> > +		if (t >= BIT(F2FS_IPU_MAX))
> > +			return -EINVAL;
> > +		if (t && f2fs_lfs_mode(sbi))
> > +			return -EINVAL;
> > +		SM_I(sbi)->ipu_policy = (unsigned int)t;
> > +		return count;
> > +	}
> > +
> >   	*ui = (unsigned int)t;
> >   	return count;