NFS refactor nfs_find_client and reference client across callback processing
Fixes a bug where the nfs_client could be freed during callback processing.
Refactor nfs_find_client to use minorversion specific means to locate the
correct nfs_client structure.
In the NFS layer, V4.0 clients are found using the callback_ident field in the
CB_COMPOUND header. V4.1 clients are found using the sessionID in the
CB_SEQUENCE operation which is also compared against the sessionID associated
with the back channel thread after a successful CREATE_SESSION.
Each of these methods finds the one an only nfs_client associated
with the incoming callback request - so nfs_find_client_next is not needed.
In the RPC layer, the pg_authenticate call needs to find the nfs_client. For
the v4.0 callback service, the callback identifier has not been decoded so a
search by address, version, and minorversion is used. The sessionid for the
sessions based callback service has (usually) not been set for the
pg_authenticate on a CB_NULL call which can be sent prior to the return
of a CREATE_SESSION call, so the sessionid associated with the back channel
thread is not used to find the client in pg_authenticate for CB_NULL calls.
Pass the referenced nfs_client to each CB_COMPOUND operation being proceesed
via the new cb_process_state structure. The reference is held across
cb_compound processing.
Use the new cb_process_state struct to move the NFS4ERR_RETRY_UNCACHED_REP
processing from process_op into nfs4_callback_sequence where it belongs.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index c0b0549..15677e7 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -16,9 +16,7 @@
#include <linux/freezer.h>
#include <linux/kthread.h>
#include <linux/sunrpc/svcauth_gss.h>
-#if defined(CONFIG_NFS_V4_1)
#include <linux/sunrpc/bc_xprt.h>
-#endif
#include <net/inet_sock.h>
@@ -384,6 +382,23 @@
return SVC_OK;
}
+/* pg_authenticate method helper */
+static struct nfs_client *nfs_cb_find_client(struct svc_rqst *rqstp)
+{
+ struct nfs4_sessionid *sessionid = bc_xprt_sid(rqstp);
+ int is_cb_compound = rqstp->rq_proc == CB_COMPOUND ? 1 : 0;
+
+ dprintk("--> %s rq_proc %d\n", __func__, rqstp->rq_proc);
+ if (svc_is_backchannel(rqstp))
+ /* Sessionid (usually) set after CB_NULL ping */
+ return nfs4_find_client_sessionid(svc_addr(rqstp), sessionid,
+ is_cb_compound);
+ else
+ /* No callback identifier in pg_authenticate */
+ return nfs4_find_client_no_ident(svc_addr(rqstp));
+}
+
+/* pg_authenticate method for nfsv4 callback threads. */
static int nfs_callback_authenticate(struct svc_rqst *rqstp)
{
struct nfs_client *clp;
@@ -391,7 +406,7 @@
int ret = SVC_OK;
/* Don't talk to strangers */
- clp = nfs_find_client(svc_addr(rqstp), 4);
+ clp = nfs_cb_find_client(rqstp);
if (clp == NULL)
return SVC_DROP;