Re: 2.6.24-rc3: find complains about /proc/net

Pavel Emelyanov [off-list ref] writes:

Rafael J. Wysocki wrote:

quoted

On Monday, 19 of November 2007, Pavel Machek wrote:

quoted

Hi!

I think that this worked before:

root@amd:/proc# find . -name "timer_info"
find: WARNING: Hard link count is wrong for ./net: this may be a bug
in your filesystem driver.  Automatically turning on find's -noleaf
option.  Earlier results may have failed to include directories that
should have been searched.
root@amd:/proc#

I'm seeing that too.

I have a better things with 2.6.24-rc3 ;)

# cd /proc/net
# ls ..
ls: reading directory ..: Not a directory

and this

# cd /proc
# find
...
./net
find: . changed during execution of find
# find net
find: net changed during execution of find
# find net/
<this works ok however>

Moreover. Program that opens /proc/net and dumps the /proc/self/fd
files produces the following:

# cd /
# a.out /proc/net
...
lr-x------  1 root root 64 Nov 20 18:02 3 -> /proc/net/net (deleted)
...
# cd /proc/net
# a.out .
...
lr-x------  1 root root 64 Nov 20 18:03 3 -> /proc/net/net (deleted)
...
# a.out ..
...
lr-x------  1 root root 64 Nov 20 18:03 3 -> /proc/net
...

This all is somehow related to the shadow proc files.
E.g. the first problem (with -ENOTDIR) is due to the shadow /proc/net
dentry doesn't implement the .readdir method:

static const struct file_operations proc_net_dir_operations = {
        .read                   = generic_read_dir,
};

And I haven't managed to find out why the rest problems
occur...

Eric, do you have fixes for it?

Duh.  There is one other possible solution I forgot to mention and
at least as a first pass it should be relatively simple.  Have the
mount of proc capture the network namespace.  I'm not certain
if it is what we want long term but it should be simple and relatively
easy to implement.

I don't like capturing the network namespace when we mount proc but
it is easier then implementing /proc/self/net.  Which is the other
real alternative.

Eric