Date: Mon, 26 Apr 1999 11:26:48 -0700 (PDT) From: Matthew Dillon <dillon@apollo.backplane.com> To: Luoqi Chen <luoqi@watermarkgroup.com> Cc: freebsd-hackers@FreeBSD.ORG, zzhang@cs.binghamton.edu Subject: Re: Logical block number caching Message-ID: <199904261826.LAA47015@apollo.backplane.com> References: <199904261612.MAA15096@lor.watermarkgroup.com>
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:> the block device for a partition to be opened while that partition is :> mounted and vice versa. :> :> Is this the same situation with FreeBSD 3.1? I have tried to find where in :> the source code this gets handled without luck. I hope someone will tell :> me whether FreeBSD uses the same strategy and which routines handle this. :> :> Any help is appreciated. :> :> -------------------------------------------------- :> Zhihui Zhang. Please visit http://www.freebsd.org :> -------------------------------------------------- :> :I believe it still applies to FreeBSD. The code that prevents mounted block :device from being opened is in miscfs/specfs/spec_vnops.c : :-lq Yes, and it would be extremely dangerous to allow any block device that the filesystem also has a handle on to be separately openned. There is no real cache coherency between logical and physical blocks - the filesystem code manages it all very carefully. -Matt Matthew Dillon <dillon@backplane.com> To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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