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Subject: Re: [PATCH v4] f2fs: compress: support chksum
To:     Jaegeuk Kim <jaegeuk@kernel.org>
CC:     <linux-f2fs-devel@lists.sourceforge.net>,
        <linux-kernel@vger.kernel.org>, <chao@kernel.org>
References: <20201208031437.56627-1-yuchao0@huawei.com>
 <22ac4df6-53ec-fb7c-c4dd-26435352a701@huawei.com>
 <X9A7Jn+cHRRcAmIi@google.com>
From:   Chao Yu <yuchao0@huawei.com>
Message-ID: <37d89d34-add1-5254-380b-233ef7a460d4@huawei.com>
Date:   Wed, 9 Dec 2020 11:05:33 +0800
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On 2020/12/9 10:49, Jaegeuk Kim wrote:
> On 12/09, Chao Yu wrote:
>> Hello guys,
>>
>> Any further comments on compress related patches?
>>
>> Jaegeuk, could you please queue these patches in dev-test? let me know
>> if there is any problem.
> 
> Chao, could you please rebase and post them in a series? I lost the patch order
> and got some conflicts when trying to merge.

I can't rebase on your dev branch, because in your branch, there is old version
of "f2fs: compress:support chksum", could you please drop old one and apply last
v4 one in the same place? and push to kernel.org.

Then I can rebase and resend patches.

Thanks,

> 
>>
>> On 2020/12/8 11:14, Chao Yu wrote:
>>> This patch supports to store chksum value with compressed
>>> data, and verify the integrality of compressed data while
>>> reading the data.
>>>
>>> The feature can be enabled through specifying mount option
>>> 'compress_chksum'.
>>>
>>> Signed-off-by: Chao Yu <yuchao0@huawei.com>
>>> ---
>>> v4:
>>> - enhance readability
>>> - remove WARN_ON_ONCE()
>>>    Documentation/filesystems/f2fs.rst |  1 +
>>>    fs/f2fs/compress.c                 | 22 ++++++++++++++++++++++
>>>    fs/f2fs/f2fs.h                     | 16 ++++++++++++++--
>>>    fs/f2fs/inode.c                    |  3 +++
>>>    fs/f2fs/super.c                    |  9 +++++++++
>>>    include/linux/f2fs_fs.h            |  2 +-
>>>    6 files changed, 50 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
>>> index b8ee761c9922..985ae7d35066 100644
>>> --- a/Documentation/filesystems/f2fs.rst
>>> +++ b/Documentation/filesystems/f2fs.rst
>>> @@ -260,6 +260,7 @@ compress_extension=%s	 Support adding specified extension, so that f2fs can enab
>>>    			 For other files, we can still enable compression via ioctl.
>>>    			 Note that, there is one reserved special extension '*', it
>>>    			 can be set to enable compression for all files.
>>> +compress_chksum		 Support verifying chksum of raw data in compressed cluster.
>>>    inlinecrypt		 When possible, encrypt/decrypt the contents of encrypted
>>>    			 files using the blk-crypto framework rather than
>>>    			 filesystem-layer encryption. This allows the use of
>>> diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
>>> index 14262e0f1cd6..9313c8695855 100644
>>> --- a/fs/f2fs/compress.c
>>> +++ b/fs/f2fs/compress.c
>>> @@ -602,6 +602,7 @@ static int f2fs_compress_pages(struct compress_ctx *cc)
>>>    				f2fs_cops[fi->i_compress_algorithm];
>>>    	unsigned int max_len, new_nr_cpages;
>>>    	struct page **new_cpages;
>>> +	u32 chksum = 0;
>>>    	int i, ret;
>>>    	trace_f2fs_compress_pages_start(cc->inode, cc->cluster_idx,
>>> @@ -655,6 +656,11 @@ static int f2fs_compress_pages(struct compress_ctx *cc)
>>>    	cc->cbuf->clen = cpu_to_le32(cc->clen);
>>> +	if (fi->i_compress_flag & 1 << COMPRESS_CHKSUM)
>>> +		chksum = f2fs_crc32(F2FS_I_SB(cc->inode),
>>> +					cc->cbuf->cdata, cc->clen);
>>> +	cc->cbuf->chksum = cpu_to_le32(chksum);
>>> +
>>>    	for (i = 0; i < COMPRESS_DATA_RESERVED_SIZE; i++)
>>>    		cc->cbuf->reserved[i] = cpu_to_le32(0);
>>> @@ -790,6 +796,22 @@ void f2fs_decompress_pages(struct bio *bio, struct page *page, bool verity)
>>>    	ret = cops->decompress_pages(dic);
>>> +	if (!ret && (fi->i_compress_flag & 1 << COMPRESS_CHKSUM)) {
>>> +		u32 provided = le32_to_cpu(dic->cbuf->chksum);
>>> +		u32 calculated = f2fs_crc32(sbi, dic->cbuf->cdata, dic->clen);
>>> +
>>> +		if (provided != calculated) {
>>> +			if (!is_inode_flag_set(dic->inode, FI_COMPRESS_CORRUPT)) {
>>> +				set_inode_flag(dic->inode, FI_COMPRESS_CORRUPT);
>>> +				printk_ratelimited(
>>> +					"%sF2FS-fs (%s): checksum invalid, nid = %lu, %x vs %x",
>>> +					KERN_INFO, sbi->sb->s_id, dic->inode->i_ino,
>>> +					provided, calculated);
>>> +			}
>>> +			set_sbi_flag(sbi, SBI_NEED_FSCK);
>>> +		}
>>> +	}
>>> +
>>>    out_vunmap_cbuf:
>>>    	vm_unmap_ram(dic->cbuf, dic->nr_cpages);
>>>    out_vunmap_rbuf:
>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>>> index 0d25f5ca5618..0b314b2034d8 100644
>>> --- a/fs/f2fs/f2fs.h
>>> +++ b/fs/f2fs/f2fs.h
>>> @@ -147,7 +147,8 @@ struct f2fs_mount_info {
>>>    	/* For compression */
>>>    	unsigned char compress_algorithm;	/* algorithm type */
>>> -	unsigned compress_log_size;		/* cluster log size */
>>> +	unsigned char compress_log_size;	/* cluster log size */
>>> +	bool compress_chksum;			/* compressed data chksum */
>>>    	unsigned char compress_ext_cnt;		/* extension count */
>>>    	unsigned char extensions[COMPRESS_EXT_NUM][F2FS_EXTENSION_LEN];	/* extensions */
>>>    };
>>> @@ -676,6 +677,7 @@ enum {
>>>    	FI_ATOMIC_REVOKE_REQUEST, /* request to drop atomic data */
>>>    	FI_VERITY_IN_PROGRESS,	/* building fs-verity Merkle tree */
>>>    	FI_COMPRESSED_FILE,	/* indicate file's data can be compressed */
>>> +	FI_COMPRESS_CORRUPT,	/* indicate compressed cluster is corrupted */
>>>    	FI_MMAP_FILE,		/* indicate file was mmapped */
>>>    	FI_MAX,			/* max flag, never be used */
>>>    };
>>> @@ -733,6 +735,7 @@ struct f2fs_inode_info {
>>>    	atomic_t i_compr_blocks;		/* # of compressed blocks */
>>>    	unsigned char i_compress_algorithm;	/* algorithm type */
>>>    	unsigned char i_log_cluster_size;	/* log of cluster size */
>>> +	unsigned short i_compress_flag;		/* compress flag */
>>>    	unsigned int i_cluster_size;		/* cluster size */
>>>    };
>>> @@ -1272,9 +1275,15 @@ enum compress_algorithm_type {
>>>    	COMPRESS_MAX,
>>>    };
>>> -#define COMPRESS_DATA_RESERVED_SIZE		5
>>> +enum compress_flag {
>>> +	COMPRESS_CHKSUM,
>>> +	COMPRESS_MAX_FLAG,
>>> +};
>>> +
>>> +#define COMPRESS_DATA_RESERVED_SIZE		4
>>>    struct compress_data {
>>>    	__le32 clen;			/* compressed data size */
>>> +	__le32 chksum;			/* compressed data chksum */
>>>    	__le32 reserved[COMPRESS_DATA_RESERVED_SIZE];	/* reserved */
>>>    	u8 cdata[];			/* compressed data */
>>>    };
>>> @@ -3888,6 +3897,9 @@ static inline void set_compress_context(struct inode *inode)
>>>    			F2FS_OPTION(sbi).compress_algorithm;
>>>    	F2FS_I(inode)->i_log_cluster_size =
>>>    			F2FS_OPTION(sbi).compress_log_size;
>>> +	F2FS_I(inode)->i_compress_flag =
>>> +			F2FS_OPTION(sbi).compress_chksum ?
>>> +				1 << COMPRESS_CHKSUM : 0;
>>>    	F2FS_I(inode)->i_cluster_size =
>>>    			1 << F2FS_I(inode)->i_log_cluster_size;
>>>    	F2FS_I(inode)->i_flags |= F2FS_COMPR_FL;
>>> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
>>> index 657db2fb6739..349d9cb933ee 100644
>>> --- a/fs/f2fs/inode.c
>>> +++ b/fs/f2fs/inode.c
>>> @@ -456,6 +456,7 @@ static int do_read_inode(struct inode *inode)
>>>    					le64_to_cpu(ri->i_compr_blocks));
>>>    			fi->i_compress_algorithm = ri->i_compress_algorithm;
>>>    			fi->i_log_cluster_size = ri->i_log_cluster_size;
>>> +			fi->i_compress_flag = le16_to_cpu(ri->i_compress_flag);
>>>    			fi->i_cluster_size = 1 << fi->i_log_cluster_size;
>>>    			set_inode_flag(inode, FI_COMPRESSED_FILE);
>>>    		}
>>> @@ -634,6 +635,8 @@ void f2fs_update_inode(struct inode *inode, struct page *node_page)
>>>    					&F2FS_I(inode)->i_compr_blocks));
>>>    			ri->i_compress_algorithm =
>>>    				F2FS_I(inode)->i_compress_algorithm;
>>> +			ri->i_compress_flag =
>>> +				cpu_to_le16(F2FS_I(inode)->i_compress_flag);
>>>    			ri->i_log_cluster_size =
>>>    				F2FS_I(inode)->i_log_cluster_size;
>>>    		}
>>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>>> index 82baaa89c893..f3d919ee4dee 100644
>>> --- a/fs/f2fs/super.c
>>> +++ b/fs/f2fs/super.c
>>> @@ -146,6 +146,7 @@ enum {
>>>    	Opt_compress_algorithm,
>>>    	Opt_compress_log_size,
>>>    	Opt_compress_extension,
>>> +	Opt_compress_chksum,
>>>    	Opt_atgc,
>>>    	Opt_err,
>>>    };
>>> @@ -214,6 +215,7 @@ static match_table_t f2fs_tokens = {
>>>    	{Opt_compress_algorithm, "compress_algorithm=%s"},
>>>    	{Opt_compress_log_size, "compress_log_size=%u"},
>>>    	{Opt_compress_extension, "compress_extension=%s"},
>>> +	{Opt_compress_chksum, "compress_chksum"},
>>>    	{Opt_atgc, "atgc"},
>>>    	{Opt_err, NULL},
>>>    };
>>> @@ -934,10 +936,14 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
>>>    			F2FS_OPTION(sbi).compress_ext_cnt++;
>>>    			kfree(name);
>>>    			break;
>>> +		case Opt_compress_chksum:
>>> +			F2FS_OPTION(sbi).compress_chksum = true;
>>> +			break;
>>>    #else
>>>    		case Opt_compress_algorithm:
>>>    		case Opt_compress_log_size:
>>>    		case Opt_compress_extension:
>>> +		case Opt_compress_chksum:
>>>    			f2fs_info(sbi, "compression options not supported");
>>>    			break;
>>>    #endif
>>> @@ -1523,6 +1529,9 @@ static inline void f2fs_show_compress_options(struct seq_file *seq,
>>>    		seq_printf(seq, ",compress_extension=%s",
>>>    			F2FS_OPTION(sbi).extensions[i]);
>>>    	}
>>> +
>>> +	if (F2FS_OPTION(sbi).compress_chksum)
>>> +		seq_puts(seq, ",compress_chksum");
>>>    }
>>>    static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
>>> diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
>>> index a5dbb57a687f..7dc2a06cf19a 100644
>>> --- a/include/linux/f2fs_fs.h
>>> +++ b/include/linux/f2fs_fs.h
>>> @@ -273,7 +273,7 @@ struct f2fs_inode {
>>>    			__le64 i_compr_blocks;	/* # of compressed blocks */
>>>    			__u8 i_compress_algorithm;	/* compress algorithm */
>>>    			__u8 i_log_cluster_size;	/* log of cluster size */
>>> -			__le16 i_padding;		/* padding */
>>> +			__le16 i_compress_flag;		/* compress flag */
>>>    			__le32 i_extra_end[0];	/* for attribute size calculation */
>>>    		} __packed;
>>>    		__le32 i_addr[DEF_ADDRS_PER_INODE];	/* Pointers to data blocks */
>>>
> .
>