From 49693532a2980f81b9e06ccb3374bccb3e39c3ea Mon Sep 17 00:00:00 2001
From: Casey Bodley <cbodley@citi.umich.edu>
Date: Tue, 1 May 2012 15:08:42 -0400
Subject: [PATCH] locks: serialize lock requests

adds a critical section to nfs41_open_state.  this lock is taken before generating the stateid/seqid, and released after updated stateid is saved to nfs41_open_state

Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
---
 daemon/lock.c  | 15 +++++++++++++--
 daemon/nfs41.h |  1 +
 daemon/open.c  |  1 +
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/daemon/lock.c b/daemon/lock.c
index 9cf4d4e..c1ac146 100644
--- a/daemon/lock.c
+++ b/daemon/lock.c
@@ -236,6 +236,8 @@ static int handle_lock(nfs41_upcall *upcall)
         goto out_free;
     }
 
+    EnterCriticalSection(&state->locks.lock);
+
     lock_stateid_arg(state, &stateid);
 
     status = nfs41_lock(state->session, &state->file, &state->owner,
@@ -244,11 +246,14 @@ static int handle_lock(nfs41_upcall *upcall)
         dprintf(LKLVL, "nfs41_lock failed with %s\n",
             nfs_error_string(status));
         status = nfs_to_windows_error(status, ERROR_BAD_NET_RESP);
+        LeaveCriticalSection(&state->locks.lock);
         goto out_free;
     }
 
     /* save lock state with the open */
     open_lock_add(state, &stateid, lock);
+    LeaveCriticalSection(&state->locks.lock);
+
     args->acquired = TRUE; /* for cancel_lock() */
 out:
     return status;
@@ -281,12 +286,15 @@ static void cancel_lock(IN nfs41_upcall *upcall)
     if (status != ERROR_LOCKED)
         goto out;
 
+    EnterCriticalSection(&state->locks.lock);
     lock_stateid_arg(state, &stateid);
 
     status = nfs41_unlock(state->session, &state->file,
         args->offset, args->length, &stateid);
 
     open_unlock_remove(state, &stateid, &input);
+    LeaveCriticalSection(&state->locks.lock);
+
     status = nfs_to_windows_error(status, ERROR_BAD_NET_RESP);
 out:
     dprintf(1, "<-- cancel_lock() returning %d\n", status);
@@ -321,8 +329,6 @@ static int handle_unlock(nfs41_upcall *upcall)
     uint32_t i;
     int status = NO_ERROR;
 
-    lock_stateid_arg(state, &stateid);
-
     for (i = 0; i < args->count; i++) {
         if (safe_read(&buf, &buf_len, &input.offset, sizeof(LONGLONG))) break;
         if (safe_read(&buf, &buf_len, &input.length, sizeof(LONGLONG))) break;
@@ -336,10 +342,15 @@ static int handle_unlock(nfs41_upcall *upcall)
         if (status != ERROR_LOCKED)
             continue;
 
+        EnterCriticalSection(&state->locks.lock);
+        lock_stateid_arg(state, &stateid);
+
         status = nfs41_unlock(state->session, &state->file,
             input.offset, input.length, &stateid);
 
         open_unlock_remove(state, &stateid, &input);
+        LeaveCriticalSection(&state->locks.lock);
+
         status = nfs_to_windows_error(status, ERROR_BAD_NET_RESP);
     }
     return status;
diff --git a/daemon/nfs41.h b/daemon/nfs41.h
index 84558ad..7aa6c18 100644
--- a/daemon/nfs41.h
+++ b/daemon/nfs41.h
@@ -149,6 +149,7 @@ typedef struct __nfs41_open_state {
         stateid4 stateid;
         struct list_entry list;
         uint32_t counter;
+        CRITICAL_SECTION lock;
     } locks;
 
     HANDLE srv_open; /* for data cache invalidation */
diff --git a/daemon/open.c b/daemon/open.c
index cf66668..8097829 100644
--- a/daemon/open.c
+++ b/daemon/open.c
@@ -61,6 +61,7 @@ static int create_open_state(
     state->ref_count = 1;
     list_init(&state->locks.list);
     list_init(&state->client_entry);
+    InitializeCriticalSection(&state->locks.lock);
 
     *state_out = state;
     status = NO_ERROR;