[PATCH] NFSv4 server - missing locking

From: "William A.(Andy) Adamson" <andros@citi.umich.edu>

sorry. i forgot to lock the nfsv4 state in nfsd4_read, nfsd4_write, and
nfsd4_setattr.

fs/nfsd/nfs4proc.c

@@ -354,6 +354,7 @@ nfsd4_read(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_read
 	if (read->rd_offset >= OFFSET_MAX)
 		return nfserr_inval;
 
+	nfsd4_lock_state();
 	status = nfs_ok;
 	/* For stateid -1, we don't check share reservations.  */
 	if (ONE_STATEID(&read->rd_stateid)) {
@@ -386,6 +387,7 @@ nfsd4_read(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_read
 	}
 	status = nfs_ok;
 out:
+	nfsd4_unlock_state();
 	read->rd_rqstp = rqstp;
 	read->rd_fhp = current_fh;
 	return status;
@@ -454,12 +456,14 @@ nfsd4_setattr(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_se
 	int status = nfs_ok;
 
 	if (setattr->sa_iattr.ia_valid & ATTR_SIZE) {
+
 		status = nfserr_bad_stateid;
 		if (ZERO_STATEID(&setattr->sa_stateid) || ONE_STATEID(&setattr->sa_stateid)) {
-		dprintk("NFSD: nfsd4_setattr: magic stateid!\n");
-		goto out;
+			dprintk("NFSD: nfsd4_setattr: magic stateid!\n");
+			return status;
 		}
 
+		nfsd4_lock_state();
 		if ((status = nfs4_preprocess_stateid_op(current_fh, 
 						&setattr->sa_stateid, 
 						CHECK_FH, &stp))) {
@@ -471,9 +475,11 @@ nfsd4_setattr(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_se
 			dprintk("NFSD: nfsd4_setattr: not opened for write!\n");
 			goto out;
 		}
+		nfsd4_unlock_state();
 	}
-	status = nfsd_setattr(rqstp, current_fh, &setattr->sa_iattr, 0, (time_t)0);
+	return (nfsd_setattr(rqstp, current_fh, &setattr->sa_iattr, 0, (time_t)0));
 out:
+	nfsd4_unlock_state();
 	return status;
 }
 
@@ -490,6 +496,7 @@ nfsd4_write(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_writ
 	if (write->wr_offset >= OFFSET_MAX)
 		return nfserr_inval;
 
+	nfsd4_lock_state();
 	if (ZERO_STATEID(stateid) || ONE_STATEID(stateid)) {
 		dprintk("NFSD: nfsd4_write: zero stateid...\n");
 		if ((status = nfs4_share_conflict(current_fh, NFS4_SHARE_DENY_WRITE))) {
@@ -511,17 +518,18 @@ nfsd4_write(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_writ
 	}
 
 zero_stateid:
-
+	nfsd4_unlock_state();
 	write->wr_bytes_written = write->wr_buflen;
 	write->wr_how_written = write->wr_stable_how;
 	p = (u32 *)write->wr_verifier;
 	*p++ = nfssvc_boot.tv_sec;
 	*p++ = nfssvc_boot.tv_usec;
 
-	status = nfsd_write(rqstp, current_fh, write->wr_offset,
+	return (nfsd_write(rqstp, current_fh, write->wr_offset,
 			  write->wr_vec, write->wr_vlen, write->wr_buflen,
-			  &write->wr_how_written);
+			  &write->wr_how_written));
 out:
+	nfsd4_unlock_state();
 	return status;
 }
 

fs/nfsd/nfs4state.c

@@ -79,6 +79,18 @@ u32 vfsclose = 0;
  */
 static struct semaphore client_sema;
 
+void
+nfsd4_lock_state(void)
+{
+	down(&client_sema);
+}
+
+void
+nfsd4_unlock_state(void)
+{
+	up(&client_sema);
+}
+
 static inline u32
 opaque_hashval(const void *ptr, int nbytes)
 {

include/linux/nfsd/state.h

@@ -167,4 +167,6 @@ extern int nfs4_preprocess_stateid_op(struct svc_fh *current_fh,
 		stateid_t *stateid, int flags, struct nfs4_stateid **stpp);
 extern int nfs4_share_conflict(struct svc_fh *current_fh, 
 		unsigned int deny_type);
+extern void nfsd4_lock_state(void);
+extern void nfsd4_unlock_state(void);
 #endif   /* NFSD4_STATE_H */