e2fsck: verify data block checksums when recovering journal

[tools/e2fsprogs.git] / lib / ext2fs / kernel-jbd.h

diff --git a/lib/ext2fs/kernel-jbd.h b/lib/ext2fs/kernel-jbd.h
index 066c031..8e0b4d6 100644 (file)
--- a/lib/ext2fs/kernel-jbd.h
+++ b/lib/ext2fs/kernel-jbd.h
@@ -114,12 +114,24 @@ typedef struct journal_header_s
 #define JBD2_CRC32_CHKSUM   1
 #define JBD2_MD5_CHKSUM     2
 #define JBD2_SHA1_CHKSUM    3
+#define JBD2_CRC32C_CHKSUM  4
 
 #define JBD2_CRC32_CHKSUM_SIZE 4
 
 #define JBD2_CHECKSUM_BYTES (32 / sizeof(__u32))
 /*
  * Commit block header for storing transactional checksums:
+ *
+ * NOTE: If FEATURE_COMPAT_CHECKSUM (checksum v1) is set, the h_chksum*
+ * fields are used to store a checksum of the descriptor and data blocks.
+ *
+ * If FEATURE_INCOMPAT_CSUM_V2 (checksum v2) is set, then the h_chksum
+ * field is used to store crc32c(uuid+commit_block).  Each journal metadata
+ * block gets its own checksum, and data block checksums are stored in
+ * journal_block_tag (in the descriptor).  The other h_chksum* fields are
+ * not used.
+ *
+ * Checksum v1 and v2 are mutually exclusive features.
  */
 struct commit_header {
        __u32           h_magic;
@@ -139,13 +151,19 @@ struct commit_header {
 typedef struct journal_block_tag_s
 {
        __u32           t_blocknr;      /* The on-disk block number */
-       __u32           t_flags;        /* See below */
+       __u16           t_checksum;     /* truncated crc32c(uuid+seq+block) */
+       __u16           t_flags;        /* See below */
        __u32           t_blocknr_high; /* most-significant high 32bits. */
 } journal_block_tag_t;
 
 #define JBD_TAG_SIZE64 (sizeof(journal_block_tag_t))
 #define JBD_TAG_SIZE32 (8)
 
+/* Tail of descriptor block, for checksumming */
+struct journal_block_tail {
+       __u32           t_checksum;
+};
+
 /*
  * The revoke descriptor: used on disk to describe a series of blocks to
  * be revoked from the log
@@ -156,6 +174,10 @@ typedef struct journal_revoke_header_s
        int              r_count;       /* Count of bytes used in the block */
 } journal_revoke_header_t;
 
+/* Tail of revoke block, for checksumming */
+struct journal_revoke_tail {
+       __u32           r_checksum;
+};
 
 /* Definitions for the journal tag flags word: */
 #define JFS_FLAG_ESCAPE                1       /* on-disk block is escaped */
@@ -205,7 +227,10 @@ typedef struct journal_superblock_s
        __u32   s_max_trans_data;       /* Limit of data blocks per trans. */
 
 /* 0x0050 */
-       __u32   s_padding[44];
+       __u8    s_checksum_type;        /* checksum type */
+       __u8    s_padding2[3];
+       __u32   s_padding[42];
+       __u32   s_checksum;             /* crc32c(superblock) */
 
 /* 0x0100 */
        __u8    s_users[16*48];         /* ids of all fs'es sharing the log */
@@ -224,11 +249,10 @@ typedef struct journal_superblock_s
 
 #define JFS_FEATURE_COMPAT_CHECKSUM    0x00000001
 
-#define JFS_FEATURE_INCOMPAT_REVOKE    0x00000001
-
 #define JFS_FEATURE_INCOMPAT_REVOKE            0x00000001
 #define JFS_FEATURE_INCOMPAT_64BIT             0x00000002
 #define JFS_FEATURE_INCOMPAT_ASYNC_COMMIT      0x00000004
+#define JFS_FEATURE_INCOMPAT_CSUM_V2           0x00000008
 
 /* Features known to this kernel version: */
 #define JFS_KNOWN_COMPAT_FEATURES      0
@@ -237,6 +261,36 @@ typedef struct journal_superblock_s
                                         JFS_FEATURE_INCOMPAT_ASYNC_COMMIT|\
                                         JFS_FEATURE_INCOMPAT_64BIT)
 
+#if (defined(E2FSCK_INCLUDE_INLINE_FUNCS) || !defined(NO_INLINE_FUNCS))
+#ifdef E2FSCK_INCLUDE_INLINE_FUNCS
+#define _INLINE_ extern
+#else
+#ifdef __GNUC__
+#define _INLINE_ extern __inline__
+#else                          /* For Watcom C */
+#define _INLINE_ extern inline
+#endif
+#endif
+
+/*
+ * helper functions to deal with 32 or 64bit block numbers.
+ */
+_INLINE_ size_t journal_tag_bytes(journal_t *journal)
+{
+       journal_block_tag_t tag;
+       size_t x = 0;
+
+       if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_CSUM_V2))
+               x += sizeof(tag.t_checksum);
+
+       if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_64BIT))
+               return x + JBD_TAG_SIZE64;
+       else
+               return x + JBD_TAG_SIZE32;
+}
+#undef _INLINE_
+#endif
+
 #ifdef __KERNEL__
 
 #include <linux/fs.h>