tree 6a912094818ff261667228a4f6d83ecc4513ac43
parent 934d375bacf9ea8a37fbfff5f3cf1c093f324095
author Chris Mason <chris.mason@oracle.com> 1228772421 -0500
committer Chris Mason <chris.mason@oracle.com> 1228772421 -0500

Btrfs: Add inode sequence number for NFS and reserved space in a few structs

This adds a sequence number to the btrfs inode that is increased on
every update.  NFS will be able to use that to detect when an inode has
changed, without relying on inaccurate time fields.

While we're here, this also:

Puts reserved space into the super block and inode

Adds a log root transid to the super so we can pick the newest super
based on the fsync log as well as the main transaction ID.  For now
the log root transid is always zero, but that'll get fixed.

Adds a starting offset to the dev_item.  This will let us do better
alignment calculations if we know the start of a partition on the disk.

Signed-off-by: Chris Mason <chris.mason@oracle.com>