NFSv4: Do not accept delegated opens when a delegation recall is in effect
...and report the servers that try to return a delegation when the client
is using the CLAIM_DELEG_CUR open mode. That behaviour is explicitly
forbidden in RFC3530.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index be2bbac..d9f4d78 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -39,6 +39,8 @@
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/string.h>
+#include <linux/ratelimit.h>
+#include <linux/printk.h>
#include <linux/slab.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/gss_api.h>
@@ -894,6 +896,8 @@
static int can_open_delegated(struct nfs_delegation *delegation, fmode_t fmode)
{
+ if (delegation == NULL)
+ return 0;
if ((delegation->type & fmode) != fmode)
return 0;
if (test_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags))
@@ -1036,8 +1040,7 @@
}
rcu_read_lock();
delegation = rcu_dereference(nfsi->delegation);
- if (delegation == NULL ||
- !can_open_delegated(delegation, fmode)) {
+ if (!can_open_delegated(delegation, fmode)) {
rcu_read_unlock();
break;
}
@@ -1091,7 +1094,12 @@
if (delegation)
delegation_flags = delegation->flags;
rcu_read_unlock();
- if ((delegation_flags & 1UL<<NFS_DELEGATION_NEED_RECLAIM) == 0)
+ if (data->o_arg.claim == NFS4_OPEN_CLAIM_DELEGATE_CUR) {
+ pr_err_ratelimited("NFS: Broken NFSv4 server %s is "
+ "returning a delegation for "
+ "OPEN(CLAIM_DELEGATE_CUR)\n",
+ NFS_CLIENT(inode)->cl_server);
+ } else if ((delegation_flags & 1UL<<NFS_DELEGATION_NEED_RECLAIM) == 0)
nfs_inode_set_delegation(state->inode,
data->owner->so_cred,
&data->o_res);
@@ -1423,11 +1431,9 @@
goto out_no_action;
rcu_read_lock();
delegation = rcu_dereference(NFS_I(data->state->inode)->delegation);
- if (delegation != NULL &&
- test_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags) == 0) {
- rcu_read_unlock();
- goto out_no_action;
- }
+ if (data->o_arg.claim != NFS4_OPEN_CLAIM_DELEGATE_CUR &&
+ can_open_delegated(delegation, data->o_arg.fmode))
+ goto unlock_no_action;
rcu_read_unlock();
}
/* Update sequence id. */
@@ -1444,6 +1450,8 @@
return;
rpc_call_start(task);
return;
+unlock_no_action:
+ rcu_read_unlock();
out_no_action:
task->tk_action = NULL;