Am 03.02.2015 um 14:48 hat Max Reitz geschrieben: > On 2015-02-03 at 04:32, Kevin Wolf wrote: > >Am 24.09.2014 um 21:48 hat Max Reitz geschrieben: > >>The BDS filename field is generally only used when opening disk images > >>or emitting error or warning messages, the only exception to this rule > >>is the map command of qemu-img. However, using exact_filename there > >>instead should not be a problem. Therefore, we can drop the filename > >>field from the BlockDriverState and use a function instead which builds > >>the filename from scratch when called. > >> > >>This is slower than reading a static char array but the problem of that > >>static array is that it may become obsolete due to changes in any > >>BlockDriverState or in the BDS graph. Using a function which rebuilds > >>the filename every time it is called resolves this problem. > >> > >>The disadvantage of worse performance is negligible, on the other hand. > >>After patch 2 of this series, which replaces some queries of > >>BDS.filename by reads from somewhere else (mostly BDS.exact_filename), > >>the filename field is only used when a disk image is opened or some > >>message should be emitted, both of which cases do not suffer from the > >>performance hit. > >Surprisingly (or not), this one needs rebasing. > > Well... > > >I tried it and it doesn't look too hard, but it's a little bit more than > >what I'm comfortable with doing while applying a series. > > I admire your courage, but I'm not sure whether this series is ready > for being applied at all. First we (or I) will have to look into how > users like libvirt which identify a BDS based on the filename can > break from applying this series.
Well, I haven't reviewed it, so I can't tell. It didn't have a (Self-)NACK and it's still on your list of to-be-merged patches, so I took a look. You're talking about courage - but I just wasn't courageous enough yet to attack your larger series... ;-) Kevin
