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| author | Darrick J. Wong <darrick.wong@oracle.com> | 2017-11-28 17:47:27 -0800 |
|---|---|---|
| committer | Darrick J. Wong <darrick.wong@oracle.com> | 2018-01-05 15:35:50 -0800 |
| commit | 14bbbf56779842217982894a4499f6cb212f655f (patch) | |
| tree | 88b91435db1b2c8bd3c9393255311b853766adeb | |
| parent | b208862aec463e3d156a66d9a14b2f7ad0388ddd (diff) | |
| download | xfs-documentation-14bbbf56779842217982894a4499f6cb212f655f.tar.gz | |
xfsdocs: clarify log item header structure2018-01-05
Make it more explicit that each log item has to start with a type code
and size, except for transaction headers.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
| -rw-r--r-- | design/XFS_Filesystem_Structure/journaling_log.asciidoc | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/design/XFS_Filesystem_Structure/journaling_log.asciidoc b/design/XFS_Filesystem_Structure/journaling_log.asciidoc index 0aec036..6109458 100644 --- a/design/XFS_Filesystem_Structure/journaling_log.asciidoc +++ b/design/XFS_Filesystem_Structure/journaling_log.asciidoc @@ -217,6 +217,18 @@ magic number to distinguish themselves. Buffer data items only appear after | +XFS_LI_BUD+ | 0x1245 | xref:BUD_Log_Item[File Block Mapping Update Done] |===== +Note that all log items (except for transaction headers) MUST start with +the following header structure. The type and size fields are baked into +each log item header, but there is not a separately defined header. + +[source, c] +---- +struct xfs_log_item { + __uint16_t magic; + __uint16_t size; +}; +---- + [[Log_Transaction_Headers]] === Transaction Headers |