On Tue, 6 Dec 2011 15:49:48 +0000 "Hawrylewicz Czarnowski, Przemyslaw" <przemyslaw.hawrylewicz.czarnowski@xxxxxxxxx> wrote: > > -----Original Message----- > > From: NeilBrown [mailto:neilb@xxxxxxx] > > Sent: Tuesday, December 06, 2011 1:56 AM > > To: Hawrylewicz Czarnowski, Przemyslaw > > Cc: linux-raid@xxxxxxxxxxxxxxx; Williams, Dan J; Labun, Marcin; > > Ciechanowski, Ed > > Subject: Re: [PATCH] imsm: fix: does not allow to use invalid chunk size > > > > On Fri, 25 Nov 2011 13:12:04 +0100 Przemyslaw Czarnowski > > <przemyslaw.hawrylewicz.czarnowski@xxxxxxxxx> wrote: > > > > > Only least significant bit of chunk size provided by user has been > > > used in test with OROM capabilities. This way user could pass value > > > which is not a power of 2. > > > > > > Signed-off-by: Przemyslaw Czarnowski > > > <przemyslaw.hawrylewicz.czarnowski@xxxxxxxxx> > > > --- > > > platform-intel.h | 4 +++- > > > 1 files changed, 3 insertions(+), 1 deletions(-) > > > > > > diff --git a/platform-intel.h b/platform-intel.h index > > > 6c094d7..99450ba 100644 > > > --- a/platform-intel.h > > > +++ b/platform-intel.h > > > @@ -124,11 +124,13 @@ static inline int imsm_orom_has_raid5(const > > > struct imsm_orom *orom) static inline int imsm_orom_has_chunk(const > > > struct imsm_orom *orom, int chunk) { > > > int fs = ffs(chunk); > > > + int orom_chunk_bit; > > > > > > if (!fs) > > > return 0; > > > fs--; /* bit num to bit index */ > > > - return !!(orom->sss & (1 << (fs - 1))); > > > + orom_chunk_bit = (orom->sss & (1 << (fs - 1))); > > > + return orom_chunk_bit && 1 << orom_chunk_bit == chunk; > > > } > > > > > > > > > > applied, thanks. > > > > However it feels a bit clumsy, though maybe that is just me. > > I would use a separate explicit test for "is a power of 2". > > ie. > > > > if (chunk & (chunk-1)) > > return 0; /* not a power of 2 */ > > fs = ffs(chunk); > > return !!(orom->sss & (1 << (fs-2))); > > > You're right, > > Please get the one from the bottom of this email then... It is based on your input (~90%) so sign it up and ship:) > Moreover previous one is not the right one I wanted to send out... Applied, thanks. NeilBrown
Attachment:
signature.asc
Description: PGP signature
