nfsd41: use current stateid by value

Signed-off-by: Tigran Mkrtchyan <kofemann@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

4 files changed, 33 insertions, 9 deletions

diff --git a/fs/nfsd/current_stateid.h b/fs/nfsd/current_stateid.h
index d8c99928b431..4123551208d8 100644
--- a/fs/nfsd/current_stateid.h
+++ b/fs/nfsd/current_stateid.h
@@ -4,6 +4,7 @@
 #include "state.h"
 #include "xdr4.h"
 
+extern void clear_current_stateid(struct nfsd4_compound_state *cstate);
 /*
  * functions to set current state id
  */
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 1ee0e7c42e97..53636ff0e6ae 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -453,7 +453,10 @@ nfsd4_restorefh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                 return nfserr_restorefh;
 
         fh_dup2(&cstate->current_fh, &cstate->save_fh);
-        cstate->current_stateid = cstate->save_stateid;
+        if (HAS_STATE_ID(cstate, SAVED_STATE_ID_FLAG)) {
+                memcpy(&cstate->current_stateid, &cstate->save_stateid, sizeof(stateid_t));
+                SET_STATE_ID(cstate, CURRENT_STATE_ID_FLAG);
+        }
         return nfs_ok;
 }
 
@@ -465,7 +468,10 @@ nfsd4_savefh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                 return nfserr_nofilehandle;
 
         fh_dup2(&cstate->save_fh, &cstate->current_fh);
-        cstate->save_stateid = cstate->current_stateid;
+        if (HAS_STATE_ID(cstate, CURRENT_STATE_ID_FLAG)) {
+                memcpy(&cstate->save_stateid, &cstate->current_stateid, sizeof(stateid_t));
+                SET_STATE_ID(cstate, SAVED_STATE_ID_FLAG);
+        }
         return nfs_ok;
 }
 
@@ -1238,7 +1244,7 @@ nfsd4_proc_compound(struct svc_rqst *rqstp,
                                 opdesc->op_set_currentstateid(cstate, &op->u);
 
                         if (opdesc->op_flags & OP_CLEAR_STATEID)
-                                cstate->current_stateid = NULL;
+                                clear_current_stateid(cstate);
 
                         if (need_wrongsec_check(rqstp))
                                 op->status = check_nfsd_access(cstate->current_fh.fh_export, rqstp);
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 7b0b6f0f69cb..cf62079e9b71 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -4699,15 +4699,23 @@ nfs4_state_shutdown(void)
 static void
 get_stateid(struct nfsd4_compound_state *cstate, stateid_t *stateid)
 {
-        if (cstate->current_stateid && CURRENT_STATEID(stateid))
-                memcpy(stateid, cstate->current_stateid, sizeof(stateid_t));
+        if (HAS_STATE_ID(cstate, CURRENT_STATE_ID_FLAG) && CURRENT_STATEID(stateid))
+                memcpy(stateid, &cstate->current_stateid, sizeof(stateid_t));
 }
 
 static void
 put_stateid(struct nfsd4_compound_state *cstate, stateid_t *stateid)
 {
-        if (cstate->minorversion)
-                cstate->current_stateid = stateid;
+        if (cstate->minorversion) {
+                memcpy(&cstate->current_stateid, stateid, sizeof(stateid_t));
+                SET_STATE_ID(cstate, CURRENT_STATE_ID_FLAG);
+        }
+}
+
+void
+clear_current_stateid(struct nfsd4_compound_state *cstate)
+{
+        CLEAR_STATE_ID(cstate, CURRENT_STATE_ID_FLAG);
 }
 
 /*
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index 3c1ddd7f13a4..12789eb3f911 100644
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -43,6 +43,13 @@
 #define NFSD4_MAX_TAGLEN        128
 #define XDR_LEN(n)                     (((n) + 3) & ~3)
 
+#define CURRENT_STATE_ID_FLAG (1<<0)
+#define SAVED_STATE_ID_FLAG (1<<1)
+
+#define SET_STATE_ID(c, f) ((c)->sid_flags |= (f))
+#define HAS_STATE_ID(c, f) ((c)->sid_flags & (f))
+#define CLEAR_STATE_ID(c, f) ((c)->sid_flags &= ~(f))
+
 struct nfsd4_compound_state {
         struct svc_fh           current_fh;
         struct svc_fh           save_fh;
@@ -54,8 +61,10 @@ struct nfsd4_compound_state {
         size_t                  iovlen;
         u32                     minorversion;
         u32                     status;
-        const stateid_t *current_stateid;
-        const stateid_t *save_stateid;
+        stateid_t       current_stateid;
+        stateid_t       save_stateid;
+        /* to indicate current and saved state id presents */
+        u32             sid_flags;
 };
 
 static inline bool nfsd4_has_session(struct nfsd4_compound_state *cs)