[PATCH] knfsd: Fix two problems that can cause rmmod nfsd to die.

From: NeilBrown
Date: Sun May 21 2006 - 21:19:33 EST


This patch applies to -mm and current -git and should go to Linus
before 2.6.17
Thanks.
NeilBrown

### Comments for Changeset

Both cause the 'entries' count in the export cache to be non-zero
at module removal time, so unregistering that cache fails and results
in an oops.

1/ exp_pseudoroot (used for NFSv4 only) leaks a reference to an export
entry.
2/ sunrpc_cache_update doesn't increment the entries count when it adds
an entry.

Thanks to "david m. richter" <richterd@xxxxxxxxxxxxxx> for triggering the
problem and finding one of the bugs.

Cc: "david m. richter" <richterd@xxxxxxxxxxxxxx>
Signed-off-by: Neil Brown <neilb@xxxxxxx>

### Diffstat output
./fs/nfsd/export.c | 4 +++-
./net/sunrpc/cache.c | 1 +
2 files changed, 4 insertions(+), 1 deletion(-)

diff ./fs/nfsd/export.c~current~ ./fs/nfsd/export.c
--- ./fs/nfsd/export.c~current~ 2006-05-22 10:55:44.000000000 +1000
+++ ./fs/nfsd/export.c 2006-05-22 10:59:40.000000000 +1000
@@ -1066,9 +1066,11 @@ exp_pseudoroot(struct auth_domain *clp,
rv = nfserr_perm;
else if (IS_ERR(exp))
rv = nfserrno(PTR_ERR(exp));
- else
+ else {
rv = fh_compose(fhp, exp,
fsid_key->ek_dentry, NULL);
+ exp_put(exp);
+ }
cache_put(&fsid_key->h, &svc_expkey_cache);
return rv;
}

diff ./net/sunrpc/cache.c~current~ ./net/sunrpc/cache.c
--- ./net/sunrpc/cache.c~current~ 2006-05-22 11:02:46.000000000 +1000
+++ ./net/sunrpc/cache.c 2006-05-22 11:03:15.000000000 +1000
@@ -159,6 +159,7 @@ struct cache_head *sunrpc_cache_update(s
detail->update(tmp, new);
tmp->next = *head;
*head = tmp;
+ detail->entries++;
cache_get(tmp);
is_new = cache_fresh_locked(tmp, new->expiry_time);
cache_fresh_locked(old, 0);
-
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