Re: Advise wanted for implementing MPP extensions to /proc file system.

Robert Cohen (Robert.Cohen@cs.anu.edu.au)
Tue, 21 May 1996 21:56:06 +1000


>>>My next idea was to use the same system of nuumbering as /proc,
>>and deal with the fact that there are duplicate inode numbers
>>in /proc/ and /proc/mpp/<cid>/ by having separate readdir and lookup
>>functions. I encoded the cell number that a file represents in the
>>data field of the proc_dir_entry structure.
>>
>>However I ran into problems with the inode hashing stuff.
>>It didnt like having duplicate inode numbers.
>>Is there a standard technique for this problem?
>>I believe that some of the existing linux file systems
>>use duplicate inode numbers.
>>
>>Should I set up a new superblock for the sub filesystem which I presume
>>would give me a new hash table?
>>Can I avoid using the hash table? I tried calling own version
>>of proc_read_inode (which didnt use iget ) from lookup
>>but I didnt register it in a superblock so the standard one
>>was called as well.

Shortly after writing this, I worked out that there is only
one inode hash table, not one per filesystem.
Therefore I presumably need to use a different device number in the
inode for the sub filesystem to avoid collision.

Hopefully that will iron out the initial problems, but advise
is still solicited on approaches/traps in this sort of area.

--
Robert