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?
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