afs: Fix creation calls in the dynamic root to fail with EOPNOTSUPP

Fix the lookup method on the dynamic root directory such that creation
calls, such as mkdir, open(O_CREAT), symlink, etc. fail with EOPNOTSUPP
rather than failing with some odd error (such as EEXIST).

lookup() itself tries to create automount directories when it is invoked.
These are cached locally in RAM and not committed to storage.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
Tested-by: Jonathan Billings <jsbillings@jsbillings.org>

diff --git a/fs/afs/dynroot.c b/fs/afs/dynroot.c
index 4150280509fff56775318ec3007a4f03c5b95454..7503899c0a1b52e2806dc7c76aebbeb4b6e667ee 100644 (file)
--- a/fs/afs/dynroot.c
+++ b/fs/afs/dynroot.c
@@ -136,6 +136,9 @@ static struct dentry *afs_dynroot_lookup(struct inode *dir, struct dentry *dentr
 
        ASSERTCMP(d_inode(dentry), ==, NULL);
 
+       if (flags & LOOKUP_CREATE)
+               return ERR_PTR(-EOPNOTSUPP);
+
        if (dentry->d_name.len >= AFSNAMEMAX) {
                _leave(" = -ENAMETOOLONG");
                return ERR_PTR(-ENAMETOOLONG);