Date: Fri, 14 Nov 2003 14:37:21 +0000 From: Peter Edwards <peter.edwards@openet-telecom.com> To: ticso@cicely.de Cc: Kris Kennaway <kris@obsecurity.org> Subject: Re: Who needs these silly statfs changes... Message-ID: <3FB4E8A1.6090402@openet-telecom.com> In-Reply-To: <20031113131057.GD22887@cicely12.cicely.de> References: <20031113020400.GA44619@xor.obsecurity.org> <20031113074425.GC39616@cirb503493.alcatel.com.au> <20031113085418.GA47995@xor.obsecurity.org> <20031113131057.GD22887@cicely12.cicely.de>
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This is a multi-part message in MIME format. --------------010306020905030705080501 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Bernd Walter wrote: >On Thu, Nov 13, 2003 at 12:54:18AM -0800, Kris Kennaway wrote: > > >>On Thu, Nov 13, 2003 at 06:44:25PM +1100, Peter Jeremy wrote: >> >> >>>On Wed, Nov 12, 2003 at 06:04:00PM -0800, Kris Kennaway wrote: >>> >>> >>>>...my sparc machine reports that my i386 nfs server has 15 exabytes of >>>>free space! >>>> >>>>enigma# df -k >>>>Filesystem 1K-blocks Used Avail Capacity Mounted on >>>>rot13:/mnt2 56595176 54032286 18014398507517260 0% /rot13/mnt2 >>>> >>>> >>>18014398507517260 = 2^54 - 1964724. and 2^54KB == 2^64 bytes. Is it >>>possible that rot13:/mnt2 has negative free space? (ie it's into the >>>8-10% reserved area). >>> >>> >>Yes, that's precisely what it is..the bug is either in df or the >>kernel (I suspect the latter, i.e. something in the nfs code). >> >> > >And it's nothing new - I'm seeing this since several years now. > > The NFS protocols have unsigned fields where statfs has signed equivalents: NFS can't represent negative available disk space ( Without the knowledge of the underlying filesystem on the server, negative free space is a little nonsensical anyway, I suppose) The attached patch stops the NFS server assigning negative values to unsigned fields in the statfs response, and works against my local solaris box. Seem reasonable? --------------010306020905030705080501 Content-Type: text/plain; name="statfs.txt" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="statfs.txt" Index: nfs_serv.c =================================================================== RCS file: /pub/FreeBSD/development/FreeBSD-CVS/src/sys/nfsserver/nfs_serv.c,v retrieving revision 1.137 diff -u -r1.137 nfs_serv.c --- nfs_serv.c 24 Oct 2003 18:36:49 -0000 1.137 +++ nfs_serv.c 14 Nov 2003 13:27:42 -0000 @@ -3812,7 +3812,7 @@ tval = (u_quad_t)sf->f_bfree; tval *= (u_quad_t)sf->f_bsize; txdr_hyper(tval, &sfp->sf_fbytes); - tval = (u_quad_t)sf->f_bavail; + tval = sf->f_bavail > 0 ? (u_quad_t)sf->f_bavail : 0; tval *= (u_quad_t)sf->f_bsize; txdr_hyper(tval, &sfp->sf_abytes); sfp->sf_tfiles.nfsuquad[0] = 0; @@ -3827,7 +3827,8 @@ sfp->sf_bsize = txdr_unsigned(sf->f_bsize); sfp->sf_blocks = txdr_unsigned(sf->f_blocks); sfp->sf_bfree = txdr_unsigned(sf->f_bfree); - sfp->sf_bavail = txdr_unsigned(sf->f_bavail); + sfp->sf_bavail = txdr_unsigned(sf->f_bavail > 0 ? + sf->f_bavail : 0); } nfsmout: if (vp) --------------010306020905030705080501--
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