afs: Locally edit directory data for mkdir/create/unlink/...

Locally edit the contents of an AFS directory upon a successful inode
operation that modifies that directory (such as mkdir, create and unlink)
so that we can avoid the current practice of re-downloading the directory
after each change.

This is viable provided that the directory version number we get back from
the modifying RPC op is exactly incremented by 1 from what we had
previously.  The data in the directory contents is in a defined format that
we have to parse locally to perform lookups and readdir, so modifying isn't
a problem.

If the edit fails, we just clear the VALID flag on the directory and it
will be reloaded next time it is needed.

Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/afs/proc.c b/fs/afs/proc.c
index 6f5a000f44a7..3212bce0d4fb 100644
--- a/fs/afs/proc.c
+++ b/fs/afs/proc.c
@@ -918,6 +918,10 @@ static int afs_proc_stats_show(struct seq_file *m, void *v)
 
 	seq_printf(m, "dir-data: rdpg=%u\n",
 		   atomic_read(&net->n_read_dir));
+
+	seq_printf(m, "dir-edit: cr=%u rm=%u\n",
+		   atomic_read(&net->n_dir_cr),
+		   atomic_read(&net->n_dir_rm));
 	return 0;
 }