Re: [patch 2/9] procfs: Convert /proc/pid/fdinfo/ handling routinesto seq-file v2

From: Al Viro
Date: Sun Aug 26 2012 - 11:06:02 EST


On Sun, Aug 26, 2012 at 06:28:20PM +0400, Cyrill Gorcunov wrote:
> On Sun, Aug 26, 2012 at 03:46:53AM +0100, Al Viro wrote:
> >
> > IMO doing that at open() time is just a headache for no good reason -
> > resolving descriptor to struct file * at read() time as we do now
> > is much saner. Better do that in your ->show(), since you are using
> > a single-shot iterator anyway...
>
> Al, the updated version is below. I suppose I can grab proc inode then
> and lookup for file position and flags at show method. (I remember
> what you've said about O_CLOEXEC bit, but I'll address this in
> another patch).

Applied, with a couple of changes:
* there's no need for those games with ihold/iput - opened file pins
its inode down just fine, TYVM.
* struct fd_info is pointless in that form - the last argument
of single_open() will end up in seq_file ->private, so let's just pass
the inode there and use m->private in ->show().

I'll push that into vfs.git#master (along with the previous patch) in a few
hours.

O_CLOEXEC is taken care of in my tree. FWIW, I'm consolidating descriptor
handling in general into fs/file.c (and I'm seriously tempted to rename
that sucker to something like fs/descriptors.c or fs/fdtable.c); some of
that stuff is already in #master. I'm probably going to move some of the
code from your fs/proc/fd.c there as well...
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