[Cluster-devel] [GFS2 PATCH] GFS2: Reduce code redundancy writing log headers

[Bob Peterson]

----- Original Message -----
| Hi,
| 
| Before this patch, there was a lot of code redundancy between functions
| log_write_header (which uses bio) and clean_journal (which uses
| buffer_head). This patch reduces the redundancy to simplify the code
| and make log header writing more consistent. We want more consistency
| and reduced redundancy because we plan to add a bunch of new fields
| to improve performance (by eliminating the local statfs and quota files)
| improve metadata integrity (by adding new crcs and such) and for better
| debugging (by adding new fields to track when and where metadata was
| pushed through the journals.) We don't want to duplicate setting these
| new fields, nor allow for human error in the process.
| 
| This reduction in code redundancy is accomplished by introducing a new
| helper function, gfs2_write_log_header which uses bio rather than bh.
| That accomplishes three things: (1) It simplifies recovery function
| clean_journal() to use the new helper function and iomap rather than
| redundancy and block_map (and eventually we can maybe remove block_map).
| (2) It adds new error checking of the bio request, if told to wait for
| IO completion. (3) It reduces the dependency on buffer_heads.
| 
| Signed-off-by: Bob Peterson <rpeterso at redhat.com>
| ---

Hi,

Self-NACK. I found a bug during testing, so I'll need to rework this.

Bob Peterson