NFSv4.1: Fall back to ordinary i/o through the mds if we have no layout segment

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/internal.h

@@ -296,7 +296,13 @@ extern int nfs_initiate_read(struct nfs_read_data *data, struct rpc_clnt *clnt,
 			     const struct rpc_call_ops *call_ops);
 extern void nfs_read_prepare(struct rpc_task *task, void *calldata);
 
+struct nfs_pageio_descriptor;
+extern void nfs_pageio_init_read_mds(struct nfs_pageio_descriptor *pgio,
+		struct inode *inode);
+
 /* write.c */
+extern void nfs_pageio_init_write_mds(struct nfs_pageio_descriptor *pgio,
+				  struct inode *inode, int ioflags);
 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

@@ -669,8 +669,6 @@ filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
 	    !nfs_generic_pg_test(pgio, prev, req))
 		return false;
 
-	if (!pgio->pg_lseg)
-		return 1;
 	p_stripe = (u64)prev->wb_index << PAGE_CACHE_SHIFT;
 	r_stripe = (u64)req->wb_index << PAGE_CACHE_SHIFT;
 	stripe_unit = FILELAYOUT_LSEG(pgio->pg_lseg)->stripe_unit;

fs/nfs/objlayout/objio_osd.c

@@ -1000,9 +1000,6 @@ static bool objio_pg_test(struct nfs_pageio_descriptor *pgio,
 	if (!pnfs_generic_pg_test(pgio, prev, req))
 		return false;
 
-	if (pgio->pg_lseg == NULL)
-		return true;
-
 	return pgio->pg_count + req->wb_bytes <=
 			OBJIO_LSEG(pgio->pg_lseg)->max_io_size;
 }

fs/nfs/pnfs.c

@@ -1066,6 +1066,10 @@ pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *r
 					   req->wb_bytes,
 					   IOMODE_READ,
 					   GFP_KERNEL);
+	/* If no lseg, fall back to read through mds */
+	if (pgio->pg_lseg == NULL)
+		nfs_pageio_init_read_mds(pgio, pgio->pg_inode);
+
 }
 EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_read);
 
@@ -1080,6 +1084,9 @@ pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *
 					   req->wb_bytes,
 					   IOMODE_RW,
 					   GFP_NOFS);
+	/* If no lseg, fall back to write through mds */
+	if (pgio->pg_lseg == NULL)
+		nfs_pageio_init_write_mds(pgio, pgio->pg_inode, pgio->pg_ioflags);
 }
 EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_write);
 

fs/nfs/read.c

@@ -114,7 +114,7 @@ static void nfs_readpage_truncate_uninitialised_page(struct nfs_read_data *data)
 	}
 }
 
-static void nfs_pageio_init_read_mds(struct nfs_pageio_descriptor *pgio,
+void nfs_pageio_init_read_mds(struct nfs_pageio_descriptor *pgio,
 		struct inode *inode)
 {
 	nfs_pageio_init(pgio, inode, &nfs_pageio_read_ops,

fs/nfs/write.c

@@ -1040,7 +1040,7 @@ static const struct nfs_pageio_ops nfs_pageio_write_ops = {
 	.pg_doio = nfs_generic_pg_writepages,
 };
 
-static void nfs_pageio_init_write_mds(struct nfs_pageio_descriptor *pgio,
+void nfs_pageio_init_write_mds(struct nfs_pageio_descriptor *pgio,
 				  struct inode *inode, int ioflags)
 {
 	nfs_pageio_init(pgio, inode, &nfs_pageio_write_ops,