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: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
index b8ee761c9922a8a9eb9006ca675a74ee0616caac..985ae7d3506679c863163adc15091f22b1a80edf 100644 (file)
--- 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 14262e0f1cd60e03b2ce2de7fbaea64baf5d3133..7ec1592a097361a67f60b350323f03ffe3028755 100644 (file)
--- 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 +796,23 @@ 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:

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 0d25f5ca5618b7370b45f65554adb0526442108d..0b314b2034d8644ab269c9591771e65d0b724671 100644 (file)
--- 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 657db2fb6739fe28f9d6bd4c8f8d268d2d489449..349d9cb933ee5473f517c2b8c50219e07bbd23e9 100644 (file)
--- 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 82baaa89c893efdd614d98e81f2db218563a5463..f3d919ee4dee68a4678c80a59ae4ecefd4c1540d 100644 (file)
--- 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 a5dbb57a687fbaa1be44b06db341016e138a4f65..7dc2a06cf19a119e11bc8abdf119eec9b54ccb82 100644 (file)
--- 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 */