Am 27.06.2014 um 13:14 hat Kevin Wolf geschrieben: > Hi Steve, > > I just discussed a problem with a qemu user on IRC, which boiled down to > him trying to open an image file on cifs with O_DIRECT, but not using a > directio mount. I understand that this probably isn't going to work > anytime soon (if at all), but it resulted in a rather unhelpful failure > mode. > > What happens is that cifs lets the open() call succeed even with the > unsupported O_DIRECT on that mount, but then fails any I/O on the file > descriptor. I believe this was introduced in commit dca69288 (which I > think is otherwise pretty useful). > > With the old behaviour, qemu detected what's going on and suggested to > use a non-O_DIRECT mode to the user, but with the new one, it got rather > unhappy after failing to find a working O_DIRECT alignment and ran into > an assertion failure... > > Now I'll certainly fix the latter in qemu, but I also think that the > behaviour of cifs is rather surprising. Any chance that you can make > open() with O_DIRECT fail again on non-directio mounts? > > Thanks, > Kevin No interest at all, not even to tell me that I'm completely wrong? :-/ Kevin
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