Re: [Qemu-devel] [RFC PATCH 3/7] block: do not pass BDRV_O_CACHE_WB to the protocol

[Paolo Bonzini]

Il 23/05/2012 14:06, Stefan Hajnoczi ha scritto:
>> > diff --git a/block.c b/block.c
>> > index 3db7150..b3d0054 100644
>> > --- a/block.c
>> > +++ b/block.c
>> > @@ -661,7 +661,7 @@ static int bdrv_open_common(BlockDriverState *bs, 
>> > const char *filename,
>> >     if (drv->bdrv_file_open) {
>> >         ret = drv->bdrv_file_open(bs, filename, open_flags);
>> >     } else {
>> > -        ret = bdrv_file_open(&bs->file, filename, open_flags);
>> > +        ret = bdrv_file_open(&bs->file, filename, open_flags & 
>> > ~BDRV_O_CACHE_WB);
> Do you really want to open image files with O_DSYNC?  For example,
> when I try these patches with -drive
> if=virtio,file=test.img,cache=none I find that the image file file
> descriptor has O_DSYNC set!  That would make cache=none equivalent to
> cache=directsync.

See the revised version I posted yesterday, this patch is bonkers. :)

What I wanted is "| BDRV_O_CACHE_WB".

Paolo