[dm-devel] dm-integrity: integrity protection device-mapper target

[Spelic]

On 01/23/13 02:29, Mikulas Patocka wrote:
> I am thinking about possibly rewriting it so that it has two hashes 
> per sector so that if either old or new data is read, at least one 
> hash matches and it won't result in data corruption. Mikulas 

Seems like a great idea, but have you thought that for it to work the 
new hash block has to be written before the new data block?

A naiive implementation would send a stream of flush requests and 
completely screw up the disk write cache...

It would be great if Linux could use ordered SCSI commands (that would 
be a feature of the disk but only of SCSI ones AFAIK, correct me if I am 
wrong) or had threaded I/O commands (that could be a feature of the 
elevator methinks) so implement dependencies among write commands and 
not completely screw up the disk cache like above. Is there any plan to 
do that?