Realpath & context sensitive symlinks
Christoph Hellwig
hch@ns.caldera.de
Fri Sep 28 01:43:00 GMT 2001
In article < 3BB372A6.D33CBCEE@mvista.com > you wrote:
> I looked through the Glibc archive but didn't see any comments on this.
>
> Some file systems (like GFS) support context dependent symlinks (CDSL).
> Thesesymlinks contain macros like {os} or {uid} which get substituted with
> the appropriate value to create an actual path name. This macro
> substitution only occurs when the file system is following a symlink,
> otherwise the macro is left unmodified.
>
> Realpath (canonicalize) doesn't know anything about these macros.
> When it finds one of these CDSLs, it treats it like a regular text
> symlink, and sticks it in the path. Lxstat fails on this path, since
> it contains funny text and isn't a real path.
>
> Anyone got a solution to this? Or suggestions?
Don't use them, pretty simple.
In Linux 2.4 we have VFS-bindings (mount --bind) that support binding
arbitrary filesystem objects to arbitrary names at runtime without
modifying the underlying filesystem.
For that reason the OpenGFS group will remove support for those butter
ugly macros in the 0.2 release, as 0.1 is supposed to stay compatible
to Sistina's GFS.
Sistina and IBM (AFS) will pronably leave the support in their filesystems,
but both codebases have other problems anyway..
Christoph
--
Whip me. Beat me. Make me maintain AIX.
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