Messages in this thread | | | Date | Mon, 5 Jan 1998 15:19:24 +0100 (MEZ) | From | Richard Guenther <> | Subject | Re: PROPOSAL: /proc/dev |
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On Thu, 1 Jan 1998, Linus Torvalds wrote:
> > Finally, I think it would be good to try to use the dcache to actually > remember the names of the files rather than having a separate data > structure for names. Too bad we didn't have the dcache when the original > /proc was done, but these days you could actually populate /proc with the > generic dcache functions: [...] > > Anyway, something like the above would be very powerful and avoid keeping > filenames around anywhere but in the dcache.. > > Linus >
I started on this kind of proc filesystem about three month ago, but never finished due to lack of time and the following problems: - we need an inode for every dentry. I tried to create them on the fly at lookup, using negative dentries and a d_revalidate - but the problems start at needing to i_get them there ... now where i_put them. (Currently inodes get created at first lookup, never freed... this leads to another problem:) - the d_count handling can not be done in the usual way, because (as we want to be able to umount/mount proc several times and of cause keep the proc-tree) the mount/umount syscalls and followups have ugly (dont rembember all) superblock->d_root handling. Ah yes, and of cause dentry->d_sb needs to change automagically, because proc has no real device id.... (partial fixes exist). - dentries don't have a user data field (easy to fix, suggested by other people, too)
BTW. the VFS looks to the iops to decide whether a file is a directory/link, why not look at inode->i_mask? This would let us put the usual file_iops, dir_iops and link_iops into one structure? Is there _any_ reason for not doing this??
Richard.
PS: if patches (early alphas) of the proc2 (TM) fs are recommended - please ask.
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