Commit b28f047b authored by Chao Yu's avatar Chao Yu Committed by Jaegeuk Kim
Browse files

f2fs: compress: support chksum 



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: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 493720a4

Documentation/filesystems/f2fs.rst

+1 −0
Original line number Diff line number Diff line
@@ -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

fs/f2fs/compress.c

+23 −0
Original line number Diff line number Diff line
@@ -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 +796,23 @@ 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);

			WARN_ON_ONCE(1);

		}

	}



out_vunmap_cbuf:

	vm_unmap_ram(dic->cbuf, dic->nr_cpages);

out_vunmap_rbuf:

fs/f2fs/f2fs.h

+14 −2
Original line number Diff line number Diff line
@@ -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;

fs/f2fs/inode.c

+3 −0
Original line number Diff line number Diff line
@@ -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;

		}

fs/f2fs/super.c

+9 −0
Original line number Diff line number Diff line
@@ -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)

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