NFSv2/v3/v4: Add support for asynchronous reads even if rsize<PAGE_CACHE_SIZE.

fs/nfs/direct.c

@@ -128,6 +128,7 @@ nfs_direct_read_seg(struct inode *inode, struct file *file,
 		.inode		= inode,
 		.args		= {
 			.fh		= NFS_FH(inode),
+			.lockowner	= current->files,
 		},
 		.res		= {
 			.fattr		= &rdata.fattr,

fs/nfs/nfs3proc.c

@@ -729,11 +729,10 @@ nfs3_read_done(struct rpc_task *task)
 }
 
 static void
-nfs3_proc_read_setup(struct nfs_read_data *data, unsigned int count)
+nfs3_proc_read_setup(struct nfs_read_data *data)
 {
 	struct rpc_task		*task = &data->task;
 	struct inode		*inode = data->inode;
-	struct nfs_page		*req;
 	int			flags;
 	struct rpc_message	msg = {
 		.rpc_proc	= &nfs3_procedures[NFS3PROC_READ],
@@ -742,26 +741,12 @@ nfs3_proc_read_setup(struct nfs_read_data *data, unsigned int count)
 		.rpc_cred	= data->cred,
 	};
 
-	req = nfs_list_entry(data->pages.next);
-	data->args.fh     = NFS_FH(inode);
-	data->args.offset = req_offset(req);
-	data->args.pgbase = req->wb_pgbase;
-	data->args.pages  = data->pagevec;
-	data->args.count  = count;
-	data->res.fattr   = &data->fattr;
-	data->res.count   = count;
-	data->res.eof     = 0;
-	
 	/* N.B. Do we need to test? Never called for swapfile inode */
 	flags = RPC_TASK_ASYNC | (IS_SWAPFILE(inode)? NFS_RPC_SWAPFLAGS : 0);
 
 	/* Finalize the task. */
 	rpc_init_task(task, NFS_CLIENT(inode), nfs3_read_done, flags);
-	task->tk_calldata = data;
-	/* Release requests */
-	task->tk_release = nfs_readdata_release;
-
-	rpc_call_setup(&data->task, &msg, 0);
+	rpc_call_setup(task, &msg, 0);
 }
 
 static void

fs/nfs/nfs4proc.c

@@ -1096,10 +1096,10 @@ nfs4_proc_read(struct nfs_read_data *rdata, struct file *filp)
 	if (filp) {
 		struct nfs4_state *state;
 		state = (struct nfs4_state *)filp->private_data;
-		nfs4_copy_stateid(&rdata->args.stateid, state, rdata->lockowner);
+		rdata->args.state = state;
 		msg.rpc_cred = state->owner->so_cred;
 	} else {
-		memcpy(&rdata->args.stateid, &zero_stateid, sizeof(rdata->args.stateid));
+		rdata->args.state = NULL;
 		msg.rpc_cred = NFS_I(inode)->mm_cred;
 	}
 
@@ -1509,20 +1509,6 @@ nfs4_proc_pathconf(struct nfs_server *server, struct nfs_fh *fhandle,
 	return nfs4_map_errors(nfs4_call_compound(&compound, NULL, 0));
 }
 
-static void
-nfs4_restart_read(struct rpc_task *task)
-{
-	struct nfs_read_data *data = (struct nfs_read_data *)task->tk_calldata;
-	struct nfs_page *req;
-
-	rpc_restart_call(task);
-	req = nfs_list_entry(data->pages.next);
-	if (req->wb_state)
-		nfs4_copy_stateid(&data->args.stateid, req->wb_state, req->wb_lockowner);
-	else
-		memcpy(&data->args.stateid, &zero_stateid, sizeof(data->args.stateid));
-}
-
 static void
 nfs4_read_done(struct rpc_task *task)
 {
@@ -1530,7 +1516,7 @@ nfs4_read_done(struct rpc_task *task)
 	struct inode *inode = data->inode;
 
 	if (nfs4_async_handle_error(task, NFS_SERVER(inode)) == -EAGAIN) {
-		task->tk_action = nfs4_restart_read;
+		rpc_restart_call(task);
 		return;
 	}
 	if (task->tk_status > 0)
@@ -1540,7 +1526,7 @@ nfs4_read_done(struct rpc_task *task)
 }
 
 static void
-nfs4_proc_read_setup(struct nfs_read_data *data, unsigned int count)
+nfs4_proc_read_setup(struct nfs_read_data *data)
 {
 	struct rpc_task	*task = &data->task;
 	struct rpc_message msg = {
@@ -1550,34 +1536,15 @@ nfs4_proc_read_setup(struct nfs_read_data *data, unsigned int count)
 		.rpc_cred = data->cred,
 	};
 	struct inode *inode = data->inode;
-	struct nfs_page *req = nfs_list_entry(data->pages.next);
 	int flags;
 
-	data->args.fh     = NFS_FH(inode);
-	data->args.offset = req_offset(req);
-	data->args.pgbase = req->wb_pgbase;
-	data->args.pages  = data->pagevec;
-	data->args.count  = count;
-	data->res.fattr   = &data->fattr;
-	data->res.count   = count;
-	data->res.eof     = 0;
 	data->timestamp   = jiffies;
 
-	data->lockowner = req->wb_lockowner;
-	if (req->wb_state)
-		nfs4_copy_stateid(&data->args.stateid, req->wb_state, req->wb_lockowner);
-	else
-		memcpy(&data->args.stateid, &zero_stateid, sizeof(data->args.stateid));
-
 	/* N.B. Do we need to test? Never called for swapfile inode */
 	flags = RPC_TASK_ASYNC | (IS_SWAPFILE(inode)? NFS_RPC_SWAPFLAGS : 0);
 
 	/* Finalize the task. */
 	rpc_init_task(task, NFS_CLIENT(inode), nfs4_read_done, flags);
-	task->tk_calldata = data;
-	/* Release requests */
-	task->tk_release = nfs_readdata_release;
-
 	rpc_call_setup(task, &msg, 0);
 }
 

fs/nfs/nfs4xdr.c

@@ -868,14 +868,32 @@ encode_putrootfh(struct xdr_stream *xdr)
         return 0;
 }
 
+static void
+encode_stateid(struct xdr_stream *xdr, struct nfs4_state *state, fl_owner_t lockowner)
+{
+	extern nfs4_stateid zero_stateid;
+	nfs4_stateid stateid;
+	uint32_t *p;
+
+	RESERVE_SPACE(16);
+	if (state != NULL) {
+		nfs4_copy_stateid(&stateid, state, lockowner);
+		WRITEMEM(stateid.data, sizeof(stateid.data));
+	} else
+		WRITEMEM(zero_stateid.data, sizeof(zero_stateid.data));
+}
+
 static int
 encode_read(struct xdr_stream *xdr, struct nfs_readargs *args)
 {
 	uint32_t *p;
 
-	RESERVE_SPACE(32);
+	RESERVE_SPACE(4);
 	WRITE32(OP_READ);
-	WRITEMEM(args->stateid.data, sizeof(args->stateid.data));
+
+	encode_stateid(xdr, args->state, args->lockowner);
+
+	RESERVE_SPACE(12);
 	WRITE64(args->offset);
 	WRITE32(args->count);
 

fs/nfs/proc.c

@@ -559,11 +559,10 @@ nfs_read_done(struct rpc_task *task)
 }
 
 static void
-nfs_proc_read_setup(struct nfs_read_data *data, unsigned int count)
+nfs_proc_read_setup(struct nfs_read_data *data)
 {
 	struct rpc_task		*task = &data->task;
 	struct inode		*inode = data->inode;
-	struct nfs_page		*req;
 	int			flags;
 	struct rpc_message	msg = {
 		.rpc_proc	= &nfs_procedures[NFSPROC_READ],
@@ -572,26 +571,12 @@ nfs_proc_read_setup(struct nfs_read_data *data, unsigned int count)
 		.rpc_cred	= data->cred,
 	};
 
-	req = nfs_list_entry(data->pages.next);
-	data->args.fh     = NFS_FH(inode);
-	data->args.offset = req_offset(req);
-	data->args.pgbase = req->wb_pgbase;
-	data->args.pages  = data->pagevec;
-	data->args.count  = count;
-	data->res.fattr   = &data->fattr;
-	data->res.count   = count;
-	data->res.eof     = 0;
-	
 	/* N.B. Do we need to test? Never called for swapfile inode */
 	flags = RPC_TASK_ASYNC | (IS_SWAPFILE(inode)? NFS_RPC_SWAPFLAGS : 0);
 
 	/* Finalize the task. */
 	rpc_init_task(task, NFS_CLIENT(inode), nfs_read_done, flags);
-	task->tk_calldata = data;
-	/* Release requests */
-	task->tk_release = nfs_readdata_release;
-
-	rpc_call_setup(&data->task, &msg, 0);
+	rpc_call_setup(task, &msg, 0);
 }
 
 static void

include/linux/nfs_fs.h

@@ -397,7 +397,6 @@ extern int  nfs_readpages(struct file *, struct address_space *,
 		struct list_head *, unsigned);
 extern int  nfs_pagein_list(struct list_head *, int);
 extern void nfs_readpage_result(struct rpc_task *);
-extern void nfs_readdata_release(struct rpc_task *);
 
 /*
  * linux/fs/mount_clnt.c

include/linux/nfs_xdr.h

@@ -229,7 +229,8 @@ struct nfs_lockres {
 
 struct nfs_readargs {
 	struct nfs_fh *		fh;
-	nfs4_stateid		stateid;
+	fl_owner_t		lockowner;
+	struct nfs4_state *	state;
 	__u64			offset;
 	__u32			count;
 	unsigned int		pgbase;
@@ -663,7 +664,6 @@ struct nfs_read_data {
 	struct rpc_task		task;
 	struct inode		*inode;
 	struct rpc_cred		*cred;
-	fl_owner_t		lockowner;
 	struct nfs_fattr	fattr;	/* fattr storage */
 	struct list_head	pages;	/* Coalesced read requests */
 	struct nfs_page		*req;	/* multi ops per nfs_page */
@@ -741,7 +741,7 @@ struct nfs_rpc_ops {
 	int	(*pathconf) (struct nfs_server *, struct nfs_fh *,
 			     struct nfs_pathconf *);
 	u32 *	(*decode_dirent)(u32 *, struct nfs_entry *, int plus);
-	void	(*read_setup)   (struct nfs_read_data *, unsigned int count);
+	void	(*read_setup)   (struct nfs_read_data *);
 	void	(*write_setup)  (struct nfs_write_data *, unsigned int count, int how);
 	void	(*commit_setup) (struct nfs_write_data *, u64 start, u32 len, int how);
 	int	(*file_open)   (struct inode *, struct file *);