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Date:   Thu, 2 Jan 2020 10:18:32 -0800
From:   Jaegeuk Kim <jaegeuk@kernel.org>
To:     Chao Yu <yuchao0@huawei.com>
Cc:     linux-f2fs-devel@lists.sourceforge.net,
        linux-kernel@vger.kernel.org, chao@kernel.org
Subject: Re: [RFC PATCH v5] f2fs: support data compression
Message-ID: <20200102181832.GA1953@jaegeuk-macbookpro.roam.corp.google.com>
References: <20191216062806.112361-1-yuchao0@huawei.com>
 <20191218214619.GA20072@jaegeuk-macbookpro.roam.corp.google.com>
 <c7035795-73b3-d832-948f-deb36213ba07@huawei.com>
 <20191231004633.GA85441@jaegeuk-macbookpro.roam.corp.google.com>
 <7a579223-39d4-7e51-c361-4aa592b2500d@huawei.com>
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In-Reply-To: <7a579223-39d4-7e51-c361-4aa592b2500d@huawei.com>
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On 12/31, Chao Yu wrote:
> On 2019/12/31 8:46, Jaegeuk Kim wrote:
> > On 12/23, Chao Yu wrote:
> >> Hi Jaegeuk,
> >>
> >> Sorry for the delay.
> >>
> >> On 2019/12/19 5:46, Jaegeuk Kim wrote:
> >>> Hi Chao,
> >>>
> >>> I still see some diffs from my latest testing version, so please check anything
> >>> that you made additionally from here.
> >>>
> >>> https://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git/commit/?h=dev&id=25d18e19a91e60837d36368ee939db13fd16dc64
> >>
> >> I've checked the diff and picked up valid parts, could you please check and
> >> comment on it?
> >>
> >> ---
> >>  fs/f2fs/compress.c |  8 ++++----
> >>  fs/f2fs/data.c     | 18 +++++++++++++++---
> >>  fs/f2fs/f2fs.h     |  3 +++
> >>  fs/f2fs/file.c     |  1 -
> >>  4 files changed, 22 insertions(+), 8 deletions(-)
> >>
> >> diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
> >> index af23ed6deffd..1bc86a54ad71 100644
> >> --- a/fs/f2fs/compress.c
> >> +++ b/fs/f2fs/compress.c
> >> @@ -593,7 +593,7 @@ static int prepare_compress_overwrite(struct compress_ctx *cc,
> >>  							fgp_flag, GFP_NOFS);
> >>  		if (!page) {
> >>  			ret = -ENOMEM;
> >> -			goto unlock_pages;
> >> +			goto release_pages;
> >>  		}
> >>
> >>  		if (PageUptodate(page))
> >> @@ -608,13 +608,13 @@ static int prepare_compress_overwrite(struct compress_ctx *cc,
> >>  		ret = f2fs_read_multi_pages(cc, &bio, cc->cluster_size,
> >>  						&last_block_in_bio, false);
> >>  		if (ret)
> >> -			goto release_pages;
> >> +			goto unlock_pages;
> >>  		if (bio)
> >>  			f2fs_submit_bio(sbi, bio, DATA);
> >>
> >>  		ret = f2fs_init_compress_ctx(cc);
> >>  		if (ret)
> >> -			goto release_pages;
> >> +			goto unlock_pages;
> >>  	}
> >>
> >>  	for (i = 0; i < cc->cluster_size; i++) {
> >> @@ -762,7 +762,7 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc,
> >>  	if (err)
> >>  		goto out_unlock_op;
> >>
> >> -	psize = (cc->rpages[last_index]->index + 1) << PAGE_SHIFT;
> >> +	psize = (loff_t)(cc->rpages[last_index]->index + 1) << PAGE_SHIFT;
> >>
> >>  	err = f2fs_get_node_info(fio.sbi, dn.nid, &ni);
> >>  	if (err)
> >> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> >> index 19cd03450066..f1f5c701228d 100644
> >> --- a/fs/f2fs/data.c
> >> +++ b/fs/f2fs/data.c
> >> @@ -184,13 +184,18 @@ static void f2fs_decompress_work(struct bio_post_read_ctx *ctx)
> >>  }
> >>
> >>  #ifdef CONFIG_F2FS_FS_COMPRESSION
> >> +void f2fs_verify_pages(struct page **rpages, unsigned int cluster_size)
> >> +{
> >> +	f2fs_decompress_end_io(rpages, cluster_size, false, true);
> >> +}
> >> +
> >>  static void f2fs_verify_bio(struct bio *bio)
> >>  {
> >>  	struct page *page = bio_first_page_all(bio);
> >>  	struct decompress_io_ctx *dic =
> >>  			(struct decompress_io_ctx *)page_private(page);
> >>
> >> -	f2fs_decompress_end_io(dic->rpages, dic->cluster_size, false, true);
> >> +	f2fs_verify_pages(dic->rpages, dic->cluster_size);
> >>  	f2fs_free_dic(dic);
> >>  }
> >>  #endif
> >> @@ -507,10 +512,16 @@ static bool __has_merged_page(struct bio *bio, struct inode *inode,
> >>  	bio_for_each_segment_all(bvec, bio, iter_all) {
> >>  		struct page *target = bvec->bv_page;
> >>
> >> -		if (fscrypt_is_bounce_page(target))
> >> +		if (fscrypt_is_bounce_page(target)) {
> >>  			target = fscrypt_pagecache_page(target);
> >> -		if (f2fs_is_compressed_page(target))
> >> +			if (IS_ERR(target))
> >> +				continue;
> >> +		}
> >> +		if (f2fs_is_compressed_page(target)) {
> >>  			target = f2fs_compress_control_page(target);
> >> +			if (IS_ERR(target))
> >> +				continue;
> >> +		}
> >>
> >>  		if (inode && inode == target->mapping->host)
> >>  			return true;
> >> @@ -2039,6 +2050,7 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
> >>  	if (ret)
> >>  		goto out;
> >>
> >> +	/* cluster was overwritten as normal cluster */
> >>  	if (dn.data_blkaddr != COMPRESS_ADDR)
> >>  		goto out;
> >>
> >> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> >> index 5d55cef66410..17d2af4eeafb 100644
> >> --- a/fs/f2fs/f2fs.h
> >> +++ b/fs/f2fs/f2fs.h
> >> @@ -2719,6 +2719,7 @@ static inline void set_compress_context(struct inode *inode)
> >>  			1 << F2FS_I(inode)->i_log_cluster_size;
> >>  	F2FS_I(inode)->i_flags |= F2FS_COMPR_FL;
> >>  	set_inode_flag(inode, FI_COMPRESSED_FILE);
> >> +	stat_inc_compr_inode(inode);
> >>  }
> >>
> >>  static inline unsigned int addrs_per_inode(struct inode *inode)
> >> @@ -3961,6 +3962,8 @@ static inline bool f2fs_force_buffered_io(struct inode *inode,
> >>  		return true;
> >>  	if (f2fs_is_multi_device(sbi))
> >>  		return true;
> >> +	if (f2fs_compressed_file(inode))
> >> +		return true;
> >>  	/*
> >>  	 * for blkzoned device, fallback direct IO to buffered IO, so
> >>  	 * all IOs can be serialized by log-structured write.
> >> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> >> index bde5612f37f5..9aeadf14413c 100644
> >> --- a/fs/f2fs/file.c
> >> +++ b/fs/f2fs/file.c
> >> @@ -1828,7 +1828,6 @@ static int f2fs_setflags_common(struct inode *inode, u32 iflags, u32 mask)
> >>  				return -EINVAL;
> >>
> >>  			set_compress_context(inode);
> >> -			stat_inc_compr_inode(inode);
> > 
> > As this breaks the count, I'll keep as is.
> 
> @@ -2719,6 +2719,7 @@ static inline void set_compress_context(struct inode *inode)
>  			1 << F2FS_I(inode)->i_log_cluster_size;
>  	F2FS_I(inode)->i_flags |= F2FS_COMPR_FL;
>  	set_inode_flag(inode, FI_COMPRESSED_FILE);
> +	stat_inc_compr_inode(inode);
> 
> If I'm not missing anything, stat_inc_compr_inode() should be called inside
> set_compress_context() in where we convert normal inode to compress one,
> right?

I don't care much whether that's right or not. If we want to do that, I found
another line to remove in f2fs_create(). Let me give it a try.

Thanks,

> 
> Thanks,
> 
> > 
> > Thanks,
> > 
> >>  		}
> >>  	}
> >>  	if ((iflags ^ fi->i_flags) & F2FS_NOCOMP_FL) {
> >> -- 
> >> 2.18.0.rc1
> >>
> >> Thanks,
> > .
> >