NFS: Clean up nfs41_check_expired_stateid()

Clean up: Instead of open-coded flag manipulation, use test_bit() and
clear_bit() just like all other accessors of the state->flag field.
This also eliminates several unnecessary implicit integer type
conversions.

To make it absolutely clear what is going on, a number of comments
are introduced.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 61 insertions, 16 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index d1c1016cd505..1364569f1d1d 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1756,32 +1756,67 @@ static int nfs4_open_expired(struct nfs4_state_owner *sp, struct nfs4_state *sta
 }
 
 #if defined(CONFIG_NFS_V4_1)
-static int nfs41_check_expired_stateid(struct nfs4_state *state, nfs4_stateid *stateid, unsigned int flags)
+static void nfs41_clear_delegation_stateid(struct nfs4_state *state)
 {
         struct nfs_server *server = NFS_SERVER(state->inode);
-        int status = -NFS4ERR_BAD_STATEID;
-
-        if (state->flags & flags) {
-                status = nfs41_test_stateid(server, stateid);
-                if (status != NFS_OK) {
-                        if (status != -NFS4ERR_BAD_STATEID)
-                                nfs41_free_stateid(server, stateid);
-                        state->flags &= ~flags;
-                }
+        nfs4_stateid *stateid = &state->stateid;
+        int status;
+
+        /* If a state reset has been done, test_stateid is unneeded */
+        if (test_bit(NFS_DELEGATED_STATE, &state->flags) == 0)
+                return;
+
+        status = nfs41_test_stateid(server, stateid);
+        if (status != NFS_OK) {
+                /* Free the stateid unless the server explicitly
+                 * informs us the stateid is unrecognized. */
+                if (status != -NFS4ERR_BAD_STATEID)
+                        nfs41_free_stateid(server, stateid);
+
+                clear_bit(NFS_DELEGATED_STATE, &state->flags);
+        }
+}
+
+/**
+ * nfs41_check_open_stateid - possibly free an open stateid
+ *
+ * @state: NFSv4 state for an inode
+ *
+ * Returns NFS_OK if recovery for this stateid is now finished.
+ * Otherwise a negative NFS4ERR value is returned.
+ */
+static int nfs41_check_open_stateid(struct nfs4_state *state)
+{
+        struct nfs_server *server = NFS_SERVER(state->inode);
+        nfs4_stateid *stateid = &state->stateid;
+        int status;
+
+        /* If a state reset has been done, test_stateid is unneeded */
+        if ((test_bit(NFS_O_RDONLY_STATE, &state->flags) == 0) &&
+            (test_bit(NFS_O_WRONLY_STATE, &state->flags) == 0) &&
+            (test_bit(NFS_O_RDWR_STATE, &state->flags) == 0))
+                return -NFS4ERR_BAD_STATEID;
+
+        status = nfs41_test_stateid(server, stateid);
+        if (status != NFS_OK) {
+                /* Free the stateid unless the server explicitly
+                 * informs us the stateid is unrecognized. */
+                if (status != -NFS4ERR_BAD_STATEID)
+                        nfs41_free_stateid(server, stateid);
+
+                clear_bit(NFS_O_RDONLY_STATE, &state->flags);
+                clear_bit(NFS_O_WRONLY_STATE, &state->flags);
+                clear_bit(NFS_O_RDWR_STATE, &state->flags);
         }
         return status;
 }
 
 static int nfs41_open_expired(struct nfs4_state_owner *sp, struct nfs4_state *state)
 {
-        int deleg_flags = 1 << NFS_DELEGATED_STATE;
-        int open_flags = (1 << NFS_O_RDONLY_STATE) | (1 << NFS_O_WRONLY_STATE) | (1 << NFS_O_RDWR_STATE);
         int status;
 
-        nfs41_check_expired_stateid(state, &state->stateid, deleg_flags);
-        status = nfs41_check_expired_stateid(state, &state->open_stateid,
-                                                        open_flags);
-
+        nfs41_clear_delegation_stateid(state);
+        status = nfs41_check_open_stateid(state);
         if (status != NFS_OK)
                 status = nfs4_open_expired(sp, state);
         return status;
@@ -4689,6 +4724,14 @@ out:
 }
 
 #if defined(CONFIG_NFS_V4_1)
+/**
+ * nfs41_check_expired_locks - possibly free a lock stateid
+ *
+ * @state: NFSv4 state for an inode
+ *
+ * Returns NFS_OK if recovery for this stateid is now finished.
+ * Otherwise a negative NFS4ERR value is returned.
+ */
 static int nfs41_check_expired_locks(struct nfs4_state *state)
 {
         int status, ret = -NFS4ERR_BAD_STATEID;
@@ -4699,6 +4742,8 @@ static int nfs41_check_expired_locks(struct nfs4_state *state)
                 if (lsp->ls_flags & NFS_LOCK_INITIALIZED) {
                         status = nfs41_test_stateid(server, &lsp->ls_stateid);
                         if (status != NFS_OK) {
+                                /* Free the stateid unless the server
+                                 * informs us the stateid is unrecognized. */
                                 if (status != -NFS4ERR_BAD_STATEID)
                                         nfs41_free_stateid(server,
                                                         &lsp->ls_stateid);