[PATCH 5/9] add support for large btree blocks with CRCs and additional RAS information

[Bill O'Donnell]

On Fri, Sep 26, 2008 at 12:56:33AM +0200, Christoph Hellwig wrote:
| Add support for larger btree blocks that contains a CRC32C checksum, a
| filesystem uuid and block number for detecting filesystem consistency
| and out of place writes.  The use of these blocks is triggered by the
| crc superblock patches just added.
| 
| Note that we currently do not log the crc of the block, but re-created
| it during log recovery.  With the pending patch to also checksum the log
| this should be safe against filesystem corruption but doesn't really
| follow the end to end argument.  Also poking into the buffer to find
| out whether this is a btree buffer during log recovery is not a very
| clean way to implement this.  I'll look into how well adding crcs
| to the buffer log items for every btree is going to work and hope
| I can switch to that variant for the next version.

looks good... will need to put this through the QA wringer.


-- 
Bill O'Donnell
SGI
billodo at sgi.com