Messages in this thread | | | Date | Thu, 24 Apr 2008 15:44:48 +0100 | From | Al Viro <> | Subject | Re: [patch 00/13] vfs: add helpers to check r/o bind mounts |
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On Thu, Apr 24, 2008 at 04:36:38PM +0200, Miklos Szeredi wrote: > > RTFS. permission() doesn't do "is that vfsmount read-only" checks, exactly > > because it's 100% bogus - either you cover it with entire area where we > > are guaranteed to stay r/w, or it's by definition racy. > > I know that. > > That does not mean, that fh_verify() needs to do vfsmount r/o checks. > AFAICS it's perfectly OK to do that later, around the vfs_ call.
... and around everything else that happens to be done after fh_verify for write access, surely? Note that e.g. nfsd_setattr() does _not_ call vfs_<anything>()...
BTW, that assumes we want to do these checks for nfsd at access time. And not go for _exports_ being r/w or r/o, with protection applying to the entire lifetime of export.
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