Date: Mon, 21 Aug 95 19:10:10 MDT From: terry@cs.weber.edu (Terry Lambert) To: current@freebsd.org Subject: Changing DEV_BSIZE Message-ID: <9508220110.AA27941@cs.weber.edu>
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Oops! Sent that one without a message body! 8-). I want to up the size of DIRBLKSIZE in ufs/ufs/dir.h to play around with some things I was playing around with before the VM changes. The dir.h code says that the DIR_BLKSIZ needs to be DEV_BSIZE to make any atomicity guarantees... this wasn't the case in the previous code. I'd like to know if making the DIRBLKSIZ 1204 (ie: DEV_BSIZE * 2) will result in problems. It seems to me that the disks are accessed in terms of pages in any case, and the comment in dir.h that says: * A directory consists of some number of blocks of DIRBLKSIZ * bytes, where DIRBLKSIZ is chosen such that it can be transferred * to disk in a single atomic operation (e.g. 512 bytes on most machines). Is in fact outdated and incorrect -- even on older pre-VM changes code, I'd think... Does anyone see a problem with this? Note that I'm not proposing this change for the generic case of everyone's UFS... just mine. If there *is* a 512 byte limit in effect here, can I up DEV_BSIZE to get around it? Is this just artificial crap to deal with frags? Terry Lambert terry@cs.weber.edu --- Any opinions in this posting are my own and not those of my present or previous employers.
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