2002-11-30 17:48:19

by John Belmonte

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Subject: seq_file / proc_fs userdata issue

The proc_fs interface supports userdata, which can be used for an
object-oriented style of programming. Used intelligently, this can
eliminate a fair amount of code redundancy in drivers that handle many
proc files.

Recently there has been work on the kernel to convert proc reads to use
seq_file. The problem is, although seq_file also has userdata support,
the userdata given to proc_fs is not automatically propagated to
seq_file. The only way to set the seq_file userdata is in the open
handler, which as far as I can tell does not have access to the
proc_dir_entry. The result is a proliferation of nearly-identical
functions and tables that could otherwise be generalized.

In summary, I'm suggesting that the proc_fs internals automatically
propagate the userdata placed in the proc_dir_entry to the seq_file
instance, so that it is available in the read handler. After all, this
is what we enjoyed before the move to seq_file.


Regards,
-John Belmonte