Re: [patch 2/6] fs: no games with DCACHE_UNHASHED

[Nick Piggin <npiggin@suse.de>]

On Thu, Oct 15, 2009 at 10:13:43AM +0200, Nick Piggin wrote:
> Now both sockets and pipes define a d_dname so they are OK, but anon_inodes
> does not. I think they should probably be made to just provide a d_dname
> anyway so we can have the familiar format of "pseudofs:[ino]" rather than
> "[pseudofs]" that we have now.
> 
> That should make this patch work for anon_inodes.c as well.

So what if we were to do this first? Are there any other reasons I've
missed? (btw. this changes the format the link if that is a problem.
Probably if we're going to do this change, we should change things like
[timerfd] to just timerfd while we're there to improve consistency
further.
--
Pipe and socket pseudo filesystems report their file descriptor link
paths as pipe:[ino] and socket:[ino]. anon_inodefs allows subsystems
to specify a name, but it does not report an associated inode number.

Implement this with anon_inodefs_dname in the same way pipefs and sockfs
are.

---
 fs/anon_inodes.c |   10 ++++++++++
 1 file changed, 10 insertions(+)

Index: linux-2.6/fs/anon_inodes.c
===================================================================
--- linux-2.6.orig/fs/anon_inodes.c
+++ linux-2.6/fs/anon_inodes.c
@@ -45,6 +45,15 @@ static int anon_inodefs_delete_dentry(st
 	return 1;
 }
 
+/*
+ * anon_inodefs_dname() is called from d_path().
+ */
+static char *anon_inodefs_dname(struct dentry *dentry, char *buffer, int buflen)
+{
+	return dynamic_dname(dentry, buffer, buflen, "%s:[%lu]",
+				dentry->d_name.name, dentry->d_inode->i_ino);
+}
+
 static struct file_system_type anon_inode_fs_type = {
 	.name		= "anon_inodefs",
 	.get_sb		= anon_inodefs_get_sb,
@@ -52,6 +61,7 @@ static struct file_system_type anon_inod
 };
 static const struct dentry_operations anon_inodefs_dentry_operations = {
 	.d_delete	= anon_inodefs_delete_dentry,
+	.d_dname	= anon_inodefs_dname,
 };
 
 /*