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:

quoted

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...