[PATCH] NFSv4 server - Read "share" state

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

this patch adds share state processing to nfsd4_read().

fs/nfsd/nfs4proc.c

@@ -346,14 +346,49 @@ nfsd4_lookup(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_loo
 static inline int
 nfsd4_read(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_read *read)
 {
+	struct nfs4_stateid *stp;
+	int status;
+
 	/* no need to check permission - this will be done in nfsd_read() */
 
 	if (read->rd_offset >= OFFSET_MAX)
 		return nfserr_inval;
 
+	status = nfs_ok;
+	/* For stateid -1, we don't check share reservations.  */
+	if (ONE_STATEID(&read->rd_stateid)) {
+		dprintk("NFSD: nfsd4_read: -1 stateid...\n");
+		goto out;
+	}
+	/*
+	* For stateid 0, the client doesn't have to have the file open, but
+	* we still check for share reservation conflicts. 
+	*/
+	if (ZERO_STATEID(&read->rd_stateid)) {
+		dprintk("NFSD: nfsd4_read: zero stateid...\n");
+		if ((status = nfs4_share_conflict(current_fh, NFS4_SHARE_DENY_READ))) {
+			dprintk("NFSD: nfsd4_read: conflicting share reservation!\n");
+			goto out;
+		}
+		status = nfs_ok;
+		goto out;
+	}
+	/* check stateid */
+	if ((status = nfs4_preprocess_stateid_op(current_fh, &read->rd_stateid, 
+					CHECK_FH, &stp))) {
+		dprintk("NFSD: nfsd4_read: couldn't process stateid!\n");
+		goto out;
+	}
+	status = nfserr_openmode;
+	if (!(stp->st_share_access & NFS4_SHARE_ACCESS_READ)) {
+		dprintk("NFSD: nfsd4_read: file not opened for read!\n");
+		goto out;
+	}
+	status = nfs_ok;
+out:
 	read->rd_rqstp = rqstp;
 	read->rd_fhp = current_fh;
-	return nfs_ok;
+	return status;
 }
 
 static inline int

include/linux/nfs.h

@@ -100,7 +100,18 @@
 	NFSERR_RECLAIM_CONFLICT = 10035,/*       v4 */
 	NFSERR_BAD_XDR = 10036,		/*       v4 */
 	NFSERR_LOCKS_HELD = 10037,	/*       v4 */
-	NFSERR_REPLAY_ME = 10038	/*       v4 */
+	NFSERR_OPENMODE = 10038,       /*       v4 */
+	NFSERR_BADOWNER = 10039,       /*       v4 */
+	NFSERR_BADCHAR = 10040,        /*       v4 */
+	NFSERR_BADNAME = 10041,        /*       v4 */
+	NFSERR_BAD_RANGE = 10042,      /*       v4 */
+	NFSERR_LOCK_NOTSUPP = 10043,   /*       v4 */
+	NFSERR_OP_ILLEGAL = 10044,     /*       v4 */
+	NFSERR_DEADLOCK = 10045,       /*       v4 */
+	NFSERR_FILE_OPEN = 10046,      /*       v4 */
+	NFSERR_ADMIN_REVOKED = 10047,  /*       v4 */
+	NFSERR_CB_PATH_DOWN = 10048,   /*       v4 */
+	NFSERR_REPLAY_ME = 10049	/*       v4 */
 };
 
 /* NFSv2 file types - beware, these are not the same in NFSv3 */

include/linux/nfs4.h

@@ -35,6 +35,7 @@
 #define NFS4_SHARE_ACCESS_READ	0x0001
 #define NFS4_SHARE_ACCESS_WRITE	0x0002
 #define NFS4_SHARE_ACCESS_BOTH	0x0003
+#define NFS4_SHARE_DENY_READ	0x0001
 
 #define NFS4_SET_TO_SERVER_TIME	0
 #define NFS4_SET_TO_CLIENT_TIME	1

include/linux/nfsd/nfsd.h

@@ -189,6 +189,7 @@ void		nfsd_lockd_shutdown(void);
 #define	nfserr_not_same		__constant_htonl(NFSERR_NOT_SAME)
 #define	nfserr_readdir_nospc	__constant_htonl(NFSERR_READDIR_NOSPC)
 #define	nfserr_bad_xdr		__constant_htonl(NFSERR_BAD_XDR)
+#define	nfserr_openmode		__constant_htonl(NFSERR_OPENMODE)
 
 /* error codes for internal use */
 /* if a request fails due to kmalloc failure, it gets dropped.

include/linux/nfsd/state.h

@@ -59,6 +59,12 @@ typedef struct {
 #define si_stateownerid   si_opaque.so_stateownerid
 #define si_fileid         si_opaque.so_fileid
 
+extern stateid_t zerostateid;
+extern stateid_t onestateid;
+
+#define ZERO_STATEID(stateid)       (!memcmp((stateid), &zerostateid, sizeof(stateid_t)))
+#define ONE_STATEID(stateid)        (!memcmp((stateid), &onestateid, sizeof(stateid_t)))
+
 /*
  * struct nfs4_client - one per client.  Clientids live here.
  * 	o Each nfs4_client is hashed by clientid.
@@ -83,13 +89,10 @@ struct nfs4_client {
 	nfs4_verifier		cl_confirm;	/* generated by server */
 };
 
-extern time_t nfs4_laundromat(void);
-int nfsd4_renew(clientid_t *clid);
-
 static inline void
 update_stateid(stateid_t *stateid)
 {
-stateid->si_generation++;
+	stateid->si_generation++;
 }
 
 /*
@@ -158,4 +161,10 @@ struct nfs4_stateid {
 	((err) != nfserr_stale_stateid) &&      \
 	((err) != nfserr_bad_stateid))
 
+extern time_t nfs4_laundromat(void);
+extern int nfsd4_renew(clientid_t *clid);
+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);
 #endif   /* NFSD4_STATE_H */