On 12 February 2014 15:25, Vyacheslav Dubeyko <slava@xxxxxxxxxxx> wrote:
> From: Vyacheslav Dubeyko <slava@xxxxxxxxxxx>
> Subject: [PATCH v3 01/15] hfsplus: add necessary declarations for journal replay
>
> The patch adds necessary declarations of HFS+ journal's
> on-disk structures, declaration of structure for journal's
> object in memory and different journal related flags.
>
> If HFSPLUS_VOL_JOURNALED is set in the volume header's attributes field,
> the volume has a journal. The journal data stuctures consist of a journal
> info block, journal header, and journal buffer. The journal info block
> indicates the location and size of the journal header and journal buffer.
> The journal buffer is the space set aside to hold transactions. The journal
> header describes which part of the journal buffer is active and contains
> transactions waiting to be committed.
>
> A single transaction consists of several blocks, including both the data
> to be written, and the location where that data is to be written. This is
> represented on disk by a block list header, which describes the number and
> sizes of the blocks, immediately followed by the contents of those blocks.
>
> The journal info block (struct hfsplus_journal_info_block) is big-endian
> structure. The rest structures of HFS+ journal (struct hfsplus_journal_header,
> struct hfsplus_blhdr, struct hfsplus_block_info) are little-endian.
Journal header and block lists are either big-endian or little-endian.
See JOURNAL_NEED_SWAP in Apple's code.
> Signed-off-by: Vyacheslav Dubeyko <slava@xxxxxxxxxxx>
> CC: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> CC: Christoph Hellwig <hch@xxxxxxxxxxxxx>
> Tested-by: Hin-Tak Leung <htl10@xxxxxxxxxxxxxxxxxxxxx>
> ---
> fs/hfsplus/hfsplus_fs.h | 23 ++++++++++++++++++++
> fs/hfsplus/hfsplus_raw.h | 53 +++++++++++++++++++++++++++++++++++++++++++++-
> 2 files changed, 75 insertions(+), 1 deletion(-)
>
> diff --git a/fs/hfsplus/hfsplus_fs.h b/fs/hfsplus/hfsplus_fs.h
> index 08846425b..18ca92c 100644
> --- a/fs/hfsplus/hfsplus_fs.h
> +++ b/fs/hfsplus/hfsplus_fs.h
> @@ -31,6 +31,11 @@
> #define DBG_BITMAP 0x00000040
> #define DBG_ATTR_MOD 0x00000080
> #define DBG_ACL_MOD 0x00000100
> +#define DBG_JOURNAL 0x00000200
> +#define DBG_JREPLAY 0x00000400
> +#define DBG_JTRANS 0x00000800
> +#define DBG_JCOMMIT 0x00001000
> +#define DBG_JCHKPT 0x00002000
>
> #if 0
> #define DBG_MASK (DBG_EXTENT|DBG_INODE|DBG_BNODE_MOD)
> @@ -126,6 +131,23 @@ struct hfs_bnode {
> #define HFS_BNODE_DIRTY 3
> #define HFS_BNODE_DELETED 4
>
> +/* An HFS+ Journal held in memory */
> +struct hfsplus_journal {
> + struct mutex jnl_lock;
> +
> + /* Journal info block specific */
> + void *jib_buf;
> + struct hfsplus_journal_info_block *jib;
> +
> + /* Journal header specific */
> + void *jh_buf;
> + struct hfsplus_journal_header *jh;
> +
> + /* TODO: Pointer of JBD */
> +
> + struct super_block *sbp;
> +};
> +
> /*
> * Attributes file states
> */
> @@ -146,6 +168,7 @@ struct hfsplus_sb_info {
> struct hfsplus_vh *s_vhdr;
> void *s_backup_vhdr_buf;
> struct hfsplus_vh *s_backup_vhdr;
> + struct hfsplus_journal *jnl;
> struct hfs_btree *ext_tree;
> struct hfs_btree *cat_tree;
> struct hfs_btree *attr_tree;
> diff --git a/fs/hfsplus/hfsplus_raw.h b/fs/hfsplus/hfsplus_raw.h
> index 8ffb3a8..a50ad9d 100644
> --- a/fs/hfsplus/hfsplus_raw.h
> +++ b/fs/hfsplus/hfsplus_raw.h
> @@ -46,6 +46,7 @@
> #define HFSP_SYMLINK_CREATOR 0x72686170 /* 'rhap' */
>
> #define HFSP_MOUNT_VERSION 0x482b4c78 /* 'H+Lx' */
> +#define HFSP_MOUNT_JOURNALED_VERSION 0x4846534A /* 'HFSJ' */
>
> /* Structures used on disk */
>
> @@ -105,7 +106,7 @@ struct hfsplus_vh {
> __be16 version;
> __be32 attributes;
> __be32 last_mount_vers;
> - u32 reserved;
> + __be32 journal_info_block;
>
> __be32 create_date;
> __be32 modify_date;
> @@ -401,4 +402,54 @@ typedef union {
> struct hfsplus_attr_key attr;
> } __packed hfsplus_btree_key;
>
> +/* HFS+ on-disk journal structures */
> +struct hfsplus_journal_info_block {
> +#define HFSPLUS_JOURNAL_IN_FS 0x01
> +#define HFSPLUS_JOURNAL_ON_OTHER_DEVICE 0x02
> +#define HFSPLUS_JOURNAL_NEED_INIT 0x04
> + __be32 flags;
> + __be32 device_signature[8];
> + __be64 offset;
> + __be64 size;
> + u32 reserved[32];
> +} __packed;
> +
> +/* Valid magic and endian value */
> +#define HFSPLUS_JOURNAL_HEADER_MAGIC 0x4A4E4C78
> +#define HFSPLUS_JOURNAL_HEADER_ENDIAN 0x12345678
> +
> +/* !!! Litle-endian structure !!! */
Not necessarily little-endian.
> +struct hfsplus_journal_header {
> + __le32 magic;
> + __le32 endian;
> + __le64 start;
> + __le64 end;
> + __le64 size; /* Includes the header and the buffer */
> + __le32 blhdr_size;
> + __le32 checksum;
> + __le32 jhdr_size;
> +} __packed;
> +
> +/* !!! Litle-endian structure !!! */
> +struct hfsplus_block_info {
> + __le64 bnum;
> + __le32 bsize;
> + union {
> + __le32 checksum;
> + __le32 seq_num; /* only used in binfo[0] */
> + } block;
> +} __packed;
> +
> +/* !!! Litle-endian structure !!! */
> +struct hfsplus_blhdr {
> + __le16 max_blocks;
> + __le16 num_blocks;
> + __le32 bytes_used;
> + __le32 checksum;
> +#define HFSPLUS_BLHDR_CHECK_CHECKSUMS 0x0001
> +#define HFSPLUS_BLHDR_FIRST_HEADER 0x0002
> + __le32 flags;
> + struct hfsplus_block_info binfo[1];
> +} __packed;
> +
> #endif
> --
So in your patchset functions hfsplus_verify_journal_header() etc.
refuse to understand BE journal.
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