Re: [PATCH v4] f2fs: compress: support chksum

From: Jaegeuk Kim
Date: Tue Dec 08 2020 - 21:49:54 EST

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.

>
> 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@xxxxxxxxxx>
> > ---
> > 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 */
> >