Messages in this thread | | | Date | Wed, 30 Apr 2008 11:48:06 +0530 | From | "NAGABHUSHAN BS" <> | Subject | Re: [RFC PATCH 0/2] Union Mount: Directory listing in glibc |
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On Tue, Apr 29, 2008 at 9:34 PM, Jan Blunck <jblunck@suse.de> wrote: > On Tue, Apr 29, bsn.0007@gmail.com wrote: > > > The RFC discussed about the information glibc readdir needs to get about > > union mounted directories and I have assumed the following information > > to be available from the kernel for this implementation. > > > > - Kernel would return all the dirents (including duplicates and whiteouts) > > starting from the topmost directory of the union. > > > > - Indication that this directory is a union mounted directory > > I have assumed that kernel would return a "." whiteout as the first > > directory entry of the union. This would tell glibc readdir(3) that it is > > working with a union mounted directory and it needs to do duplicate > > elimination and whiteout suppression. It starts building a dirent cache > > for this purpose. > > IIRC the intention was to emit a "." whiteout when "changing" from one > directory to the next. That means when the first directory is completely read > the whiteout is emitted. After that glibc knows to start duplicate > removal. >
Yes the intention was to get a "." whiteout when changing from one directory to next and thats essentially what i have assumed, for starting duplicate elimination. Along with that i have also assumed to get a "." whiteout as the first directory entry of the union, so as to indicate to glibc that the directory is a union mounted directory.
Regards Nagabhushan
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