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-rw-r--r--fs/ext4/bitmap.c83
1 files changed, 83 insertions, 0 deletions
diff --git a/fs/ext4/bitmap.c b/fs/ext4/bitmap.c
index fa3af81ac565..b319721da26a 100644
--- a/fs/ext4/bitmap.c
+++ b/fs/ext4/bitmap.c
@@ -29,3 +29,86 @@ unsigned int ext4_count_free(struct buffer_head *map, unsigned int numchars)
#endif /* EXT4FS_DEBUG */
+int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
+ struct ext4_group_desc *gdp,
+ struct buffer_head *bh, int sz)
+{
+ __u32 hi;
+ __u32 provided, calculated;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+ if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+ return 1;
+
+ provided = le16_to_cpu(gdp->bg_inode_bitmap_csum_lo);
+ calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
+ if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END) {
+ hi = le16_to_cpu(gdp->bg_inode_bitmap_csum_hi);
+ provided |= (hi << 16);
+ } else
+ calculated &= 0xFFFF;
+
+ return provided == calculated;
+}
+
+void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
+ struct ext4_group_desc *gdp,
+ struct buffer_head *bh, int sz)
+{
+ __u32 csum;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+ if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+ return;
+
+ csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
+ gdp->bg_inode_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
+ if (sbi->s_desc_size >= EXT4_BG_INODE_BITMAP_CSUM_HI_END)
+ gdp->bg_inode_bitmap_csum_hi = cpu_to_le16(csum >> 16);
+}
+
+int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
+ struct ext4_group_desc *gdp,
+ struct buffer_head *bh, int sz)
+{
+ __u32 hi;
+ __u32 provided, calculated;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+ if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+ return 1;
+
+ provided = le16_to_cpu(gdp->bg_block_bitmap_csum_lo);
+ calculated = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
+ if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END) {
+ hi = le16_to_cpu(gdp->bg_block_bitmap_csum_hi);
+ provided |= (hi << 16);
+ } else
+ calculated &= 0xFFFF;
+
+ if (provided == calculated)
+ return 1;
+
+ ext4_error(sb, "Bad block bitmap checksum: block_group = %u", group);
+ return 0;
+}
+
+void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
+ struct ext4_group_desc *gdp,
+ struct buffer_head *bh, int sz)
+{
+ __u32 csum;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+ if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+ return;
+
+ csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)bh->b_data, sz);
+ gdp->bg_block_bitmap_csum_lo = cpu_to_le16(csum & 0xFFFF);
+ if (sbi->s_desc_size >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_END)
+ gdp->bg_block_bitmap_csum_hi = cpu_to_le16(csum >> 16);
+}