Date: Wed, 2 Aug 2006 05:04:53 +1000 From: Peter Jeremy <peterjeremy@optushome.com.au> To: Eric Anderson <anderson@centtech.com> Cc: freebsd-hackers@freebsd.org, rick-freebsd@kiwi-computer.com Subject: Re: [PATCH] adding two new options to 'cp' Message-ID: <20060801190453.GD717@turion.vk2pj.dyndns.org> In-Reply-To: <44CF94A4.3000306@centtech.com> References: <44CE199C.2020500@centtech.com> <17614.8289.134373.387558@bhuda.mired.org> <96b30c400607310847s1d2f845eo212b234d03f51e9a@mail.gmail.com> <17614.10982.499561.139268@bhuda.mired.org> <ealpn1$lan$1@sea.gmane.org> <20060801072611.GA717@turion.vk2pj.dyndns.org> <20060801171150.GB3413@megan.kiwi-computer.com> <44CF8F1A.5090506@centtech.com> <20060801174048.GE3413@megan.kiwi-computer.com> <44CF94A4.3000306@centtech.com>
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--SO98HVl1bnMOfKZd Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, 2006-Aug-01 12:51:32 -0500, Eric Anderson wrote: >string of zeros larger than the block size, or it needs to 'do the right= =20 >thing' and determine if it's sparse or not. You can do this by comparing stat.st_size with stat.st_blocks - a sparse file will have fewer blocks than its size requires. What you can't do is accurately determine where the holes are. Note that st_blksize is not nessarily the allocation blocksize and therefore is unrelated to the size of holes in the filesystem. Also, on FreeBSD, the designation of "optimal" is a misnomer and I/O operations should be much larger than this for optimal efficiency. --=20 Peter Jeremy --SO98HVl1bnMOfKZd Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.4 (FreeBSD) iD8DBQFEz6XU/opHv/APuIcRAvE4AJoDnQ182fq7H5d8xPFjdM9eWHO4HQCfY1Rc bRpeb1FabKXVxYvM9sfwV5I= =RNRl -----END PGP SIGNATURE----- --SO98HVl1bnMOfKZd--
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