NFS: Move the pnfs write code into pnfs.c

...and ensure that we recoalese to take into account differences in
differences in block sizes when falling back to write through the MDS.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/internal.h

@@ -305,8 +305,12 @@ extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
 extern void nfs_readdata_release(struct nfs_read_data *rdata);
 
 /* write.c */
+extern int nfs_generic_flush(struct nfs_pageio_descriptor *desc,
+		struct list_head *head);
 extern void nfs_pageio_init_write_mds(struct nfs_pageio_descriptor *pgio,
 				  struct inode *inode, int ioflags);
+extern void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio);
+extern void nfs_writedata_release(struct nfs_write_data *wdata);
 extern void nfs_commit_free(struct nfs_write_data *p);
 extern int nfs_initiate_write(struct nfs_write_data *data,
 			      struct rpc_clnt *clnt,

fs/nfs/nfs4filelayout.c

@@ -741,7 +741,7 @@ static const struct nfs_pageio_ops filelayout_pg_read_ops = {
 static const struct nfs_pageio_ops filelayout_pg_write_ops = {
 	.pg_init = filelayout_pg_init_write,
 	.pg_test = filelayout_pg_test,
-	.pg_doio = nfs_generic_pg_writepages,
+	.pg_doio = pnfs_generic_pg_writepages,
 };
 
 static bool filelayout_mark_pnfs_commit(struct pnfs_layout_segment *lseg)

fs/nfs/objlayout/objio_osd.c

@@ -1013,7 +1013,7 @@ static const struct nfs_pageio_ops objio_pg_read_ops = {
 static const struct nfs_pageio_ops objio_pg_write_ops = {
 	.pg_init = pnfs_generic_pg_init_write,
 	.pg_test = objio_pg_test,
-	.pg_doio = nfs_generic_pg_writepages,
+	.pg_doio = pnfs_generic_pg_writepages,
 };
 
 static struct pnfs_layoutdriver_type objlayout_type = {

fs/nfs/pnfs.c

@@ -1170,15 +1170,30 @@ pnfs_ld_write_done(struct nfs_write_data *data)
 }
 EXPORT_SYMBOL_GPL(pnfs_ld_write_done);
 
-enum pnfs_try_status
+static void
+pnfs_write_through_mds(struct nfs_pageio_descriptor *desc,
+		struct nfs_write_data *data)
+{
+	list_splice_tail_init(&data->pages, &desc->pg_list);
+	if (data->req && list_empty(&data->req->wb_list))
+		nfs_list_add_request(data->req, &desc->pg_list);
+	nfs_pageio_reset_write_mds(desc);
+	desc->pg_recoalesce = 1;
+	nfs_writedata_release(data);
+}
+
+static enum pnfs_try_status
 pnfs_try_to_write_data(struct nfs_write_data *wdata,
-			const struct rpc_call_ops *call_ops, int how)
+			const struct rpc_call_ops *call_ops,
+			struct pnfs_layout_segment *lseg,
+			int how)
 {
 	struct inode *inode = wdata->inode;
 	enum pnfs_try_status trypnfs;
 	struct nfs_server *nfss = NFS_SERVER(inode);
 
 	wdata->mds_ops = call_ops;
+	wdata->lseg = get_lseg(lseg);
 
 	dprintk("%s: Writing ino:%lu %u@%llu (how %d)\n", __func__,
 		inode->i_ino, wdata->args.count, wdata->args.offset, how);
@@ -1194,6 +1209,44 @@ pnfs_try_to_write_data(struct nfs_write_data *wdata,
 	return trypnfs;
 }
 
+static void
+pnfs_do_multiple_writes(struct nfs_pageio_descriptor *desc, struct list_head *head, int how)
+{
+	struct nfs_write_data *data;
+	const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
+	struct pnfs_layout_segment *lseg = desc->pg_lseg;
+
+	desc->pg_lseg = NULL;
+	while (!list_empty(head)) {
+		enum pnfs_try_status trypnfs;
+
+		data = list_entry(head->next, struct nfs_write_data, list);
+		list_del_init(&data->list);
+
+		trypnfs = pnfs_try_to_write_data(data, call_ops, lseg, how);
+		if (trypnfs == PNFS_NOT_ATTEMPTED)
+			pnfs_write_through_mds(desc, data);
+	}
+	put_lseg(lseg);
+}
+
+int
+pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
+{
+	LIST_HEAD(head);
+	int ret;
+
+	ret = nfs_generic_flush(desc, &head);
+	if (ret != 0) {
+		put_lseg(desc->pg_lseg);
+		desc->pg_lseg = NULL;
+		return ret;
+	}
+	pnfs_do_multiple_writes(desc, &head, desc->pg_ioflags);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_pg_writepages);
+
 /*
  * Called by non rpc-based layout drivers
  */

fs/nfs/pnfs.h

@@ -155,11 +155,10 @@ bool pnfs_pageio_init_write(struct nfs_pageio_descriptor *, struct inode *, int)
 
 void set_pnfs_layoutdriver(struct nfs_server *, u32 id);
 void unset_pnfs_layoutdriver(struct nfs_server *);
-enum pnfs_try_status pnfs_try_to_write_data(struct nfs_write_data *,
-					     const struct rpc_call_ops *, int);
 void pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *, struct nfs_page *);
 int pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc);
 void pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *, struct nfs_page *);
+int pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc);
 bool pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev, struct nfs_page *req);
 int pnfs_layout_process(struct nfs4_layoutget *lgp);
 void pnfs_free_lseg_list(struct list_head *tmp_list);
@@ -328,13 +327,6 @@ static inline void put_lseg(struct pnfs_layout_segment *lseg)
 {
 }
 
-static inline enum pnfs_try_status
-pnfs_try_to_write_data(struct nfs_write_data *data,
-		       const struct rpc_call_ops *call_ops, int how)
-{
-	return PNFS_NOT_ATTEMPTED;
-}
-
 static inline int pnfs_return_layout(struct inode *ino)
 {
 	return 0;

fs/nfs/write.c

@@ -97,7 +97,7 @@ void nfs_writedata_free(struct nfs_write_data *p)
 	mempool_free(p, nfs_wdata_mempool);
 }
 
-static void nfs_writedata_release(struct nfs_write_data *wdata)
+void nfs_writedata_release(struct nfs_write_data *wdata)
 {
 	put_lseg(wdata->lseg);
 	put_nfs_open_context(wdata->args.context);
@@ -887,25 +887,15 @@ static void nfs_write_rpcsetup(struct nfs_page *req,
 
 static int nfs_do_write(struct nfs_write_data *data,
 		const struct rpc_call_ops *call_ops,
-		struct pnfs_layout_segment *lseg,
 		int how)
 {
 	struct inode *inode = data->args.context->path.dentry->d_inode;
 
-	if (lseg != NULL) {
-		data->lseg = get_lseg(lseg);
-		if (pnfs_try_to_write_data(data, call_ops, how) == PNFS_ATTEMPTED)
-			return 0;
-		put_lseg(data->lseg);
-		data->lseg = NULL;
-	}
-
 	return nfs_initiate_write(data, NFS_CLIENT(inode), call_ops, how);
 }
 
 static int nfs_do_multiple_writes(struct list_head *head,
 		const struct rpc_call_ops *call_ops,
-		struct pnfs_layout_segment *lseg,
 		int how)
 {
 	struct nfs_write_data *data;
@@ -917,7 +907,7 @@ static int nfs_do_multiple_writes(struct list_head *head,
 		data = list_entry(head->next, struct nfs_write_data, list);
 		list_del_init(&data->list);
 		
-		ret2 = nfs_do_write(data, call_ops, lseg, how);
+		ret2 = nfs_do_write(data, call_ops, how);
 		 if (ret == 0)
 			 ret = ret2;
 	}
@@ -1037,23 +1027,24 @@ static int nfs_flush_one(struct nfs_pageio_descriptor *desc, struct list_head *r
 	return ret;
 }
 
-int nfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
+int nfs_generic_flush(struct nfs_pageio_descriptor *desc, struct list_head *head)
+{
+	if (desc->pg_bsize < PAGE_CACHE_SIZE)
+		return nfs_flush_multi(desc, head);
+	return nfs_flush_one(desc, head);
+}
+
+static int nfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
 {
 	LIST_HEAD(head);
 	int ret;
 
-	if (desc->pg_bsize < PAGE_CACHE_SIZE)
-		ret = nfs_flush_multi(desc, &head);
-	else
-		ret = nfs_flush_one(desc, &head);
+	ret = nfs_generic_flush(desc, &head);
 	if (ret == 0)
 		ret = nfs_do_multiple_writes(&head, desc->pg_rpc_callops,
-				desc->pg_lseg, desc->pg_ioflags);
-	put_lseg(desc->pg_lseg);
-	desc->pg_lseg = NULL;
+				desc->pg_ioflags);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(nfs_generic_pg_writepages);
 
 static const struct nfs_pageio_ops nfs_pageio_write_ops = {
 	.pg_test = nfs_generic_pg_test,
@@ -1068,6 +1059,12 @@ void nfs_pageio_init_write_mds(struct nfs_pageio_descriptor *pgio,
 }
 EXPORT_SYMBOL_GPL(nfs_pageio_init_write_mds);
 
+void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio)
+{
+	pgio->pg_ops = &nfs_pageio_write_ops;
+	pgio->pg_bsize = NFS_SERVER(pgio->pg_inode)->wsize;
+}
+
 static void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
 				  struct inode *inode, int ioflags)
 {

include/linux/nfs_page.h

@@ -108,9 +108,6 @@ extern	void nfs_unlock_request(struct nfs_page *req);
 extern	int nfs_set_page_tag_locked(struct nfs_page *req);
 extern  void nfs_clear_page_tag_locked(struct nfs_page *req);
 
-extern	int nfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc);
-
-
 /*
  * Lock the page of an asynchronous request without getting a new reference
  */