[PATCH] nfsd4: use existing open instead of reopening on read and write

Use the struct file * obtained in nfsd4_open for nfsd_read and nfsd_write when
available.

To do this we add a struct file * argument to nfsd_read and nfsd_write.  If a
struct file is passed in, nfsd_read and nfsd_write will use it, doing just an
access check instead of an open and close.  If the new argument is NULL, they
will fall back on the old behaviour.
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/nfsd/nfs3proc.c

@@ -171,7 +171,7 @@ nfsd3_proc_read(struct svc_rqst *rqstp, struct nfsd3_readargs *argp,
 	svc_reserve(rqstp, ((1 + NFS3_POST_OP_ATTR_WORDS + 3)<<2) + resp->count +4);
 
 	fh_copy(&resp->fh, &argp->fh);
-	nfserr = nfsd_read(rqstp, &resp->fh,
+	nfserr = nfsd_read(rqstp, &resp->fh, NULL,
 				  argp->offset,
 			   	  argp->vec, argp->vlen,
 				  &resp->count);
@@ -201,7 +201,7 @@ nfsd3_proc_write(struct svc_rqst *rqstp, struct nfsd3_writeargs *argp,
 
 	fh_copy(&resp->fh, &argp->fh);
 	resp->committed = argp->stable;
-	nfserr = nfsd_write(rqstp, &resp->fh,
+	nfserr = nfsd_write(rqstp, &resp->fh, NULL,
 				   argp->offset,
 				   argp->vec, argp->vlen,
 				   argp->len,

fs/nfsd/nfs4proc.c

@@ -464,6 +464,7 @@ static inline int
 nfsd4_read(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_read *read)
 {
 	int status;
+	struct file *filp = NULL;
 
 	/* no need to check permission - this will be done in nfsd_read() */
 
@@ -472,8 +473,8 @@ nfsd4_read(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_read
 
 	nfs4_lock_state();
 	/* check stateid */
-	if ((status = nfs4_preprocess_stateid_op(current_fh, &read->rd_stateid, 
-					CHECK_FH | RD_STATE))) {
+	if ((status = nfs4_preprocess_stateid_op(current_fh, &read->rd_stateid,
+					CHECK_FH | RD_STATE, &filp))) {
 		dprintk("NFSD: nfsd4_read: couldn't process stateid!\n");
 		goto out;
 	}
@@ -482,6 +483,7 @@ nfsd4_read(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_read
 	nfs4_unlock_state();
 	read->rd_rqstp = rqstp;
 	read->rd_fhp = current_fh;
+	read->rd_filp = filp;
 	return status;
 }
 
@@ -574,7 +576,7 @@ nfsd4_setattr(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_se
 		nfs4_lock_state();
 		if ((status = nfs4_preprocess_stateid_op(current_fh, 
 						&setattr->sa_stateid, 
-						CHECK_FH | WR_STATE))) {
+						CHECK_FH | WR_STATE, NULL))) {
 			dprintk("NFSD: nfsd4_setattr: couldn't process stateid!\n");
 			goto out_unlock;
 		}
@@ -598,6 +600,7 @@ static inline int
 nfsd4_write(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_write *write)
 {
 	stateid_t *stateid = &write->wr_stateid;
+	struct file *filp = NULL;
 	u32 *p;
 	int status = nfs_ok;
 
@@ -608,7 +611,7 @@ nfsd4_write(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_writ
 
 	nfs4_lock_state();
 	if ((status = nfs4_preprocess_stateid_op(current_fh, stateid, 
-					CHECK_FH | WR_STATE))) {
+					CHECK_FH | WR_STATE, &filp))) {
 		dprintk("NFSD: nfsd4_write: couldn't process stateid!\n");
 		goto out;
 	}
@@ -620,9 +623,10 @@ nfsd4_write(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_writ
 	*p++ = nfssvc_boot.tv_sec;
 	*p++ = nfssvc_boot.tv_usec;
 
-	status =  nfsd_write(rqstp, current_fh, write->wr_offset,
-			  write->wr_vec, write->wr_vlen, write->wr_buflen,
-			  &write->wr_how_written);
+	status =  nfsd_write(rqstp, current_fh, filp, write->wr_offset,
+			write->wr_vec, write->wr_vlen, write->wr_buflen,
+			&write->wr_how_written);
+
 	if (status == nfserr_symlink)
 		status = nfserr_inval;
 	return status;

fs/nfsd/nfs4state.c

@@ -2042,7 +2042,7 @@ io_during_grace_disallowed(struct inode *inode, int flags)
 * Checks for stateid operations
 */
 int
-nfs4_preprocess_stateid_op(struct svc_fh *current_fh, stateid_t *stateid, int flags)
+nfs4_preprocess_stateid_op(struct svc_fh *current_fh, stateid_t *stateid, int flags, struct file **filpp)
 {
 	struct nfs4_stateid *stp = NULL;
 	struct nfs4_delegation *dp = NULL;
@@ -2053,6 +2053,8 @@ nfs4_preprocess_stateid_op(struct svc_fh *current_fh, stateid_t *stateid, int fl
 	dprintk("NFSD: preprocess_stateid_op: stateid = (%08x/%08x/%08x/%08x)\n",
 		stateid->si_boot, stateid->si_stateownerid, 
 		stateid->si_fileid, stateid->si_generation); 
+	if (filpp)
+		*filpp = NULL;
 
 	if (io_during_grace_disallowed(ino, flags))
 		return nfserr_grace;
@@ -2099,6 +2101,8 @@ nfs4_preprocess_stateid_op(struct svc_fh *current_fh, stateid_t *stateid, int fl
 		if ((status = nfs4_check_openmode(stp,flags)))
 			goto out;
 		renew_client(stp->st_stateowner->so_client);
+		if (filpp)
+			*filpp = stp->st_vfs_file;
 	} else if (dp) {
 		if ((status = nfs4_check_delegmode(dp, flags)))
 			goto out;
@@ -2405,7 +2409,7 @@ nfsd4_delegreturn(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd
 		goto out;
 
 	nfs4_lock_state();
-	status = nfs4_preprocess_stateid_op(current_fh, &dr->dr_stateid, DELEG_RET);
+	status = nfs4_preprocess_stateid_op(current_fh, &dr->dr_stateid, DELEG_RET, NULL);
 	nfs4_unlock_state();
 out:
 	return status;

fs/nfsd/nfs4xdr.c

@@ -2068,10 +2068,10 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_read
 	}
 	read->rd_vlen = v;
 
-	nfserr = nfsd_read(read->rd_rqstp, read->rd_fhp,
-			   read->rd_offset,
-			   read->rd_iov, read->rd_vlen,
-			   &maxcount);
+	nfserr = nfsd_read(read->rd_rqstp, read->rd_fhp, read->rd_filp,
+			read->rd_offset, read->rd_iov, read->rd_vlen,
+			&maxcount);
+
 	if (nfserr == nfserr_symlink)
 		nfserr = nfserr_inval;
 	if (nfserr)

fs/nfsd/nfsproc.c

@@ -137,7 +137,7 @@ nfsd_proc_read(struct svc_rqst *rqstp, struct nfsd_readargs *argp,
 	svc_reserve(rqstp, (19<<2) + argp->count + 4);
 
 	resp->count = argp->count;
-	nfserr = nfsd_read(rqstp, fh_copy(&resp->fh, &argp->fh),
+	nfserr = nfsd_read(rqstp, fh_copy(&resp->fh, &argp->fh), NULL,
 				  argp->offset,
 			   	  argp->vec, argp->vlen,
 				  &resp->count);
@@ -160,7 +160,7 @@ nfsd_proc_write(struct svc_rqst *rqstp, struct nfsd_writeargs *argp,
 		SVCFH_fmt(&argp->fh),
 		argp->len, argp->offset);
 
-	nfserr = nfsd_write(rqstp, fh_copy(&resp->fh, &argp->fh),
+	nfserr = nfsd_write(rqstp, fh_copy(&resp->fh, &argp->fh), NULL,
 				   argp->offset,
 				   argp->vec, argp->vlen,
 				   argp->len,

fs/nfsd/vfs.c

@@ -810,30 +810,21 @@ nfsd_read_actor(read_descriptor_t *desc, struct page *page, unsigned long offset
 	return size;
 }
 
-/*
- * Read data from a file. count must contain the requested read count
- * on entry. On return, *count contains the number of bytes actually read.
- * N.B. After this call fhp needs an fh_put
- */
-int
-nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
-          struct kvec *vec, int vlen, unsigned long *count)
+static inline int
+nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
+              loff_t offset, struct kvec *vec, int vlen, unsigned long *count)
 {
+	struct inode *inode;
 	struct raparms	*ra;
 	mm_segment_t	oldfs;
 	int		err;
-	struct file	*file;
-	struct inode	*inode;
 
-	err = nfsd_open(rqstp, fhp, S_IFREG, MAY_READ, &file);
-	if (err)
-		goto out;
 	err = nfserr_perm;
 	inode = file->f_dentry->d_inode;
 #ifdef MSNFS
 	if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
 		(!lock_may_read(inode, offset, *count)))
-		goto out_close;
+		goto out;
 #endif
 
 	/* Get readahead parameters */
@@ -869,41 +860,28 @@ nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
 		dnotify_parent(file->f_dentry, DN_ACCESS);
 	} else 
 		err = nfserrno(err);
-out_close:
-	nfsd_close(file);
 out:
 	return err;
 }
 
-/*
- * Write data to a file.
- * The stable flag requests synchronous writes.
- * N.B. After this call fhp needs an fh_put
- */
-int
-nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
-				struct kvec *vec, int vlen,
+static inline int
+nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
+				loff_t offset, struct kvec *vec, int vlen,
 	   			unsigned long cnt, int *stablep)
 {
 	struct svc_export	*exp;
-	struct file		*file;
 	struct dentry		*dentry;
 	struct inode		*inode;
 	mm_segment_t		oldfs;
 	int			err = 0;
 	int			stable = *stablep;
 
-	err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file);
-	if (err)
-		goto out;
-	if (!cnt)
-		goto out_close;
 	err = nfserr_perm;
 
 #ifdef MSNFS
 	if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
 		(!lock_may_write(file->f_dentry->d_inode, offset, cnt)))
-		goto out_close;
+		goto out;
 #endif
 
 	dentry = file->f_dentry;
@@ -990,12 +968,71 @@ nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
 		err = 0;
 	else 
 		err = nfserrno(err);
-out_close:
-	nfsd_close(file);
 out:
 	return err;
 }
 
+/*
+ * Read data from a file. count must contain the requested read count
+ * on entry. On return, *count contains the number of bytes actually read.
+ * N.B. After this call fhp needs an fh_put
+ */
+int
+nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
+		loff_t offset, struct kvec *vec, int vlen,
+		unsigned long *count)
+{
+	int		err;
+
+	if (file) {
+		err = nfsd_permission(fhp->fh_export, fhp->fh_dentry,
+				MAY_READ|MAY_OWNER_OVERRIDE);
+		if (err)
+			goto out;
+		err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
+	} else {
+		err = nfsd_open(rqstp, fhp, S_IFREG, MAY_READ, &file);
+		if (err)
+			goto out;
+		err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
+		nfsd_close(file);
+	}
+out:
+	return err;
+}
+
+/*
+ * Write data to a file.
+ * The stable flag requests synchronous writes.
+ * N.B. After this call fhp needs an fh_put
+ */
+int
+nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
+		loff_t offset, struct kvec *vec, int vlen, unsigned long cnt,
+		int *stablep)
+{
+	int			err = 0;
+
+	if (file) {
+		err = nfsd_permission(fhp->fh_export, fhp->fh_dentry,
+				MAY_WRITE|MAY_OWNER_OVERRIDE);
+		if (err)
+			goto out;
+		err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt,
+				stablep);
+	} else {
+		err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file);
+		if (err)
+			goto out;
+
+		if (cnt)
+			err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen,
+					     cnt, stablep);
+		nfsd_close(file);
+	}
+out:
+	return err;
+}
 
 #ifdef CONFIG_NFSD_V3
 /*

include/linux/nfsd/nfsd.h

@@ -96,9 +96,9 @@ int		nfsd_commit(struct svc_rqst *, struct svc_fh *,
 int		nfsd_open(struct svc_rqst *, struct svc_fh *, int,
 				int, struct file **);
 void		nfsd_close(struct file *);
-int		nfsd_read(struct svc_rqst *, struct svc_fh *,
-				loff_t, struct kvec *,int, unsigned long *);
-int		nfsd_write(struct svc_rqst *, struct svc_fh *,
+int 		nfsd_read(struct svc_rqst *, struct svc_fh *, struct file *,
+				loff_t, struct kvec *, int, unsigned long *);
+int 		nfsd_write(struct svc_rqst *, struct svc_fh *,struct file *,
 				loff_t, struct kvec *,int, unsigned long, int *);
 int		nfsd_readlink(struct svc_rqst *, struct svc_fh *,
 				char *, int *);

include/linux/nfsd/state.h

@@ -279,7 +279,7 @@ struct nfs4_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);
+		stateid_t *stateid, int flags, struct file **filp);
 extern int nfs4_share_conflict(struct svc_fh *current_fh, 
 		unsigned int deny_type);
 extern void nfs4_lock_state(void);

include/linux/nfsd/xdr4.h

@@ -241,6 +241,7 @@ struct nfsd4_read {
 	u32		rd_length;          /* request */
 	struct kvec	rd_iov[RPCSVC_MAXPAGES];
 	int		rd_vlen;
+	struct file     *rd_filp;
 	
 	struct svc_rqst *rd_rqstp;          /* response */
 	struct svc_fh * rd_fhp;             /* response */