Kevin Wolf <kw...@redhat.com> writes: > Am 30.06.2010 13:55, schrieb Markus Armbruster: >> raw_pread_aligned() retries up to two times if the block device backs >> a virtual CD-ROM. This makes no sense. Whether retrying reads can >> correct read errors may depend on what we're reading, not on how the >> result gets used. >> >> Also clean up gratuitous use of goto. >> >> This reverts what's left of commit 8c05dbf9. >> >> Signed-off-by: Markus Armbruster <arm...@redhat.com> > > Are you sure that this won't cause a regression? I mean if there is a > patch specifically adding this behaviour, there probably was a problem > that made someone touch the code in the first place. > > Arguably checking for the type hint is nonsense, however I think the > case for which this was written is passing through a real CD-ROM to a VM > - in which case the condition would be true anyway. > > So instead of removing the code, the fix to achieve what was probably > intended is to check for bs->drv == &bdrv_host_cdrom.
I can do that. But does it make sense? How can retrying failed reads help? Isn't the OS in a much better position to retry? Keeping the retry code feels like voodoo-programming to me: I have no idea how waving around this dead chicken could help, but we've always done it, so keep waving ;)
