[XFS SUMMIT] Online Fsck Status Update

[XFS SUMMIT] Online Fsck Status Update

[Darrick J. Wong]

Hi everyone,

This one is meant to be a status update about where I am with online
repair.  The btree bulk loading code went upstream for 5.7, which will
enable us to refactor a lot of boilerplate code out of xfs_repair.

At this point, I have finished fleshing out nearly all of the online
repair functionality.  We can rebuild all per-AG btrees and the inode
fork mapping btrees.  With the deferred inactivation series and fs
freezing, we can also rebuild the rmapbt and run quotacheck on a frozen
filesystem, which means that quotas can be repaired too.

More recently, I've written repair code for the realtime bitmap and
summary files; and preliminary versions of extended attribute and
directory salvaging.  With the new atomic extent swap series, I can now
commit rebuilt metadata atomically.

However, the directory tree reconstruction part is /very/ difficult to
achieve without parent pointers, since we cannot easily reconnect
orphaned files without scanning the entire directory tree under fs
freeze.  We also can't do nlink verification easily without parent
pointer validation.

--D

https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/log/?h=scrub-rtsummary
https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/log/?h=repair-ag-btrees
https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/log/?h=repair-inodes
https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/log/?h=repair-inode-data
https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/log/?h=repair-fsfile-metadata
https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/log/?h=repair-metadata-atomically