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Newsgroups: comp.os.386bsd.development Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!agate!dog.ee.lbl.gov!hellgate.utah.edu!fcom.cc.utah.edu!cs.weber.edu!terry From: terry@cs.weber.edu (A Wizard of Earth C) Subject: Re: File Truncation Philosophy Message-ID: <1993Apr8.050452.7600@fcom.cc.utah.edu> Sender: news@fcom.cc.utah.edu Organization: Weber State University (Ogden, UT) References: <1993Apr2.140809.16589@cm.cf.ac.uk>> <BLYMN.93Apr3213001@siren.awadi.com.au> <C4z32z.ExC@veda.is> Date: Thu, 8 Apr 93 05:04:52 GMT Lines: 35 In article <C4z32z.ExC@veda.is> adam@veda.is (Adam David) writes: [ ... method of avoiding the problem by juggling inodes ... ] >Have I missed anything important, or could this really work? How about: it's not portable internally and would have to be rewritten for each and every file system type that was (A) writable and (B) contained executables *AND* it fixes a problem with the way the VM system handles swapping by hacking the file system. Seriously, the canonical method is returning an EBUSY or ETXTBSY, checking for it in vncalls.c, and then making calls to the VM system to have swap back the file instead of the program image in the file doing it, and then retrying the operation (again, in vncalls.c). This would give the advantage of quick-start without the disadvantage of paging from the file, since the from-file store would be fixed *above* the UFS/PCFS/XYZZYFS layer. The intermediate soloution of returning EBUSY/ETXTBSY has a long and ignoble history, and should be allowable; the main issue is allowing an unlink/rm of a file while it's running, something I don't think the VTEXT soloution allows. Terry Lambert terry@icarus.weber.edu terry_lambert@novell.com --- Any opinions in this posting are my own and not those of my present or previous employers. -- ------------------------------------------------------------------------------- "I have an 8 user poetic license" - me Get the 386bsd FAQ from agate.berkeley.edu:/pub/386BSD/386bsd-0.1/unofficial -------------------------------------------------------------------------------