tree 51b1af9b58dfcf1b561888a6752255ac86070808
parent 941e6d7d09aaf455c0d7ad383f7f5ae67e4ccf16
author Steven Whitehouse <swhiteho@redhat.com> 1201516655 +0000
committer Steven Whitehouse <swhiteho@redhat.com> 1206956386 +0100

[GFS2] Streamline indirect pointer tree height calculation

This patch improves the calculation of the tree height in order to reduce
the number of operations which are carried out on each call to gfs2_block_map.
In the common case, we now make a single comparison, rather than calculating
the required tree height from scratch each time. Also in the case that the
tree does need some extra height, we start from the current height rather from
zero when we work out what the new height ought to be.

In addition the di_height field is moved into the inode proper and reduced
in size to a u8 since the value must be between 0 and GFS2_MAX_META_HEIGHT (10).

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>