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Subject: Re: [RFC PATCH v5] f2fs: support data compression
To:     Jaegeuk Kim <jaegeuk@kernel.org>
CC:     <linux-f2fs-devel@lists.sourceforge.net>,
        <linux-kernel@vger.kernel.org>, <chao@kernel.org>
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>
From:   Chao Yu <yuchao0@huawei.com>
Message-ID: <7a579223-39d4-7e51-c361-4aa592b2500d@huawei.com>
Date:   Tue, 31 Dec 2019 09:45:51 +0800
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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?

Thanks,

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