NFSv4: Fix up stateid locking...

We really don't need to grab both the state->so_owner and the
inode->i_lock.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 6 insertions, 4 deletions

diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 4fa4054cdf34..523cc2cbb5e1 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -307,6 +307,7 @@ nfs4_alloc_open_state(void)
         atomic_set(&state->count, 1);
         INIT_LIST_HEAD(&state->lock_states);
         spin_lock_init(&state->state_lock);
+        seqlock_init(&state->seqlock);
         return state;
 }
 
@@ -411,7 +412,6 @@ void nfs4_put_open_state(struct nfs4_state *state)
  */
 void nfs4_close_state(struct path *path, struct nfs4_state *state, mode_t mode)
 {
-        struct inode *inode = state->inode;
         struct nfs4_state_owner *owner = state->owner;
         int call_close = 0;
         int newstate;
@@ -419,7 +419,6 @@ void nfs4_close_state(struct path *path, struct nfs4_state *state, mode_t mode)
         atomic_inc(&owner->so_count);
         /* Protect against nfs4_find_state() */
         spin_lock(&owner->so_lock);
-        spin_lock(&inode->i_lock);
         switch (mode & (FMODE_READ | FMODE_WRITE)) {
                 case FMODE_READ:
                         state->n_rdonly--;
@@ -446,7 +445,6 @@ void nfs4_close_state(struct path *path, struct nfs4_state *state, mode_t mode)
                         clear_bit(NFS_DELEGATED_STATE, &state->flags);
         }
         nfs4_state_set_mode_locked(state, newstate);
-        spin_unlock(&inode->i_lock);
         spin_unlock(&owner->so_lock);
 
         if (!call_close) {
@@ -599,8 +597,12 @@ int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
 void nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t fl_owner)
 {
         struct nfs4_lock_state *lsp;
+        int seq;
 
-        memcpy(dst, &state->stateid, sizeof(*dst));
+        do {
+                seq = read_seqbegin(&state->seqlock);
+                memcpy(dst, &state->stateid, sizeof(*dst));
+        } while (read_seqretry(&state->seqlock, seq));
         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
                 return;