Commit 3790ee4b authored by Eric W. Biederman's avatar Eric W. Biederman Committed by Linus Torvalds

proc: remove/Fix proc generic d_revalidate

Ultimately to implement /proc perfectly we need an implementation of
d_revalidate because files and directories can be removed behind the back
of the VFS, and d_revalidate is the only way we can let the VFS know that
this has happened.

Unfortunately the linux VFS can not cope with anything in the path to a
mount point going away.  So a proper d_revalidate method that calls d_drop
also needs to call have_submounts which is moderately expensive, so you
really don't want a d_revalidate method that unconditionally calls it, but
instead only calls it when the backing object has really gone away.

proc generic entries only disappear on module_unload (when not counting the
fledgling network namespace) so it is quite rare that we actually encounter
that case and has not actually caused us real world trouble yet.

So until we get a proper test for keeping dentries in the dcache fix the
current d_revalidate method by completely removing it.  This returns us to
the current status quo.

So with CONFIG_NETNS=n things should look as they have always looked.

For CONFIG_NETNS=y things work most of the time but there are a few rare
corner cases that don't behave properly.  As the network namespace is
barely present in 2.6.24 this should not be a problem.
Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "Denis V. Lunev" <den@openvz.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d84248bf
...@@ -374,16 +374,9 @@ static int proc_delete_dentry(struct dentry * dentry) ...@@ -374,16 +374,9 @@ static int proc_delete_dentry(struct dentry * dentry)
return 1; return 1;
} }
static int proc_revalidate_dentry(struct dentry *dentry, struct nameidata *nd)
{
d_drop(dentry);
return 0;
}
static struct dentry_operations proc_dentry_operations = static struct dentry_operations proc_dentry_operations =
{ {
.d_delete = proc_delete_dentry, .d_delete = proc_delete_dentry,
.d_revalidate = proc_revalidate_dentry,
}; };
/* /*
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment