On Fri, 22 Feb 2013, Theodore Ts'o wrote: > Date: Fri, 22 Feb 2013 00:10:48 -0500 > From: Theodore Ts'o <tytso@xxxxxxx> > To: Lukas Czerner <lczerner@xxxxxxxxxx> > Cc: linux-ext4@xxxxxxxxxxxxxxx > Subject: Re: [PATCH] ext4: fix free clusters calculation in bigalloc > filesystem > > On Thu, Feb 21, 2013 at 09:01:05AM +0100, Lukas Czerner wrote: > > > > Moreover when calculating number of root clusters we should be using > > macro EXT4_NUM_B2C() instead of EXT4_C2B() otherwise the result will > > usually be off by one. > > That should be "instead of EXT4_B2C()", and I don't think this is > true, since the number of blocks should always be a multiple of the > cluster ratio. So the use of EXT4_B2C() is a bit of an optimization > (it avoids an add and mask operation), but it's probably not a > measurable optimizatoin in practice. > > - Ted Oh right it was EXT4_B2C(), I'll update the description. Even though it should always be a multiple of cluster ratio it's really bad precedence for the use of EXT4_B2C() since it is confusing enough as it is with blocks/clusters. I'll resend. -Lukas -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
