Add the JBD2 journaling layer transaction management from the
Linux 6.18 kernel ext4 filesystem driver.
transaction.c handles:
- Transaction lifecycle (start, stop, restart)
- Handle management for filesystem operations
- Buffer attachment to transactions
- Transaction state machine
- Credit reservation and accounting
- Metadata and data buffer journaling
This is the core transaction API that ext4 uses to ensure
atomic updates to filesystem metadata.
Co-developed-by: Claude Opus 4.5 <noreply@anthropic.com>
Signed-off-by: Simon Glass <simon.glass@canonical.com>
d2feaa01d8