diff options
| author | Darrick J. Wong <djwong@us.ibm.com> | 2012-05-22 22:43:41 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2012-05-22 22:43:41 -0400 |
| commit | 8f888ef846d4481e24c74b4a91ece771d2bcbcb5 (patch) | |
| tree | bd037514671c52cea95426ba417a6c1b4b59f96a /include/linux/jbd2.h | |
| parent | f32aaf2d2b996b14e993da1c23f7ee22ea7333a3 (diff) | |
jbd2: change disk layout for metadata checksumming
Define flags and allocate space in on-disk journal structures to support
checksumming of journal metadata.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'include/linux/jbd2.h')
| -rw-r--r-- | include/linux/jbd2.h | 30 |
1 files changed, 28 insertions, 2 deletions
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index 912c30a8ddb..809c439066c 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -147,12 +147,24 @@ 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 { __be32 h_magic; @@ -175,13 +187,19 @@ struct commit_header { typedef struct journal_block_tag_s { __be32 t_blocknr; /* The on-disk block number */ - __be32 t_flags; /* See below */ + __be16 t_checksum; /* truncated crc32c(uuid+seq+block) */ + __be16 t_flags; /* See below */ __be32 t_blocknr_high; /* most-significant high 32bits. */ } journal_block_tag_t; #define JBD2_TAG_SIZE32 (offsetof(journal_block_tag_t, t_blocknr_high)) #define JBD2_TAG_SIZE64 (sizeof(journal_block_tag_t)) +/* Tail of descriptor block, for checksumming */ +struct jbd2_journal_block_tail { + __be32 t_checksum; /* crc32c(uuid+descr_block) */ +}; + /* * The revoke descriptor: used on disk to describe a series of blocks to * be revoked from the log @@ -192,6 +210,10 @@ typedef struct jbd2_journal_revoke_header_s __be32 r_count; /* Count of bytes used in the block */ } jbd2_journal_revoke_header_t; +/* Tail of revoke block, for checksumming */ +struct jbd2_journal_revoke_tail { + __be32 r_checksum; /* crc32c(uuid+revoke_block) */ +}; /* Definitions for the journal tag flags word: */ #define JBD2_FLAG_ESCAPE 1 /* on-disk block is escaped */ @@ -241,7 +263,10 @@ typedef struct journal_superblock_s __be32 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]; + __be32 s_checksum; /* crc32c(superblock) */ /* 0x0100 */ __u8 s_users[16*48]; /* ids of all fs'es sharing the log */ @@ -263,6 +288,7 @@ typedef struct journal_superblock_s #define JBD2_FEATURE_INCOMPAT_REVOKE 0x00000001 #define JBD2_FEATURE_INCOMPAT_64BIT 0x00000002 #define JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT 0x00000004 +#define JBD2_FEATURE_INCOMPAT_CSUM_V2 0x00000008 /* Features known to this kernel version: */ #define JBD2_KNOWN_COMPAT_FEATURES JBD2_FEATURE_COMPAT_CHECKSUM |