NFS: Clean up O_DIRECT request allocation

Rather than adjusting the index+offset after the call to
nfs_create_request(), add a function nfs_page_create_from_page() that
takes an offset.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/direct.c

@@ -343,14 +343,12 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
 			struct nfs_page *req;
 			unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase);
 			/* XXX do we need to do the eof zeroing found in async_filler? */
-			req = nfs_create_request(dreq->ctx, pagevec[i],
-						 pgbase, req_len);
+			req = nfs_page_create_from_page(dreq->ctx, pagevec[i],
+							pgbase, pos, req_len);
 			if (IS_ERR(req)) {
 				result = PTR_ERR(req);
 				break;
 			}
-			req->wb_index = pos >> PAGE_SHIFT;
-			req->wb_offset = pos & ~PAGE_MASK;
 			if (!nfs_pageio_add_request(&desc, req)) {
 				result = desc.pg_error;
 				nfs_release_request(req);
@@ -802,8 +800,8 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
 			struct nfs_page *req;
 			unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase);
 
-			req = nfs_create_request(dreq->ctx, pagevec[i],
-						 pgbase, req_len);
+			req = nfs_page_create_from_page(dreq->ctx, pagevec[i],
+							pgbase, pos, req_len);
 			if (IS_ERR(req)) {
 				result = PTR_ERR(req);
 				break;
@@ -816,8 +814,6 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
 			}
 
 			nfs_lock_request(req);
-			req->wb_index = pos >> PAGE_SHIFT;
-			req->wb_offset = pos & ~PAGE_MASK;
 			if (!nfs_pageio_add_request(&desc, req)) {
 				result = desc.pg_error;
 				nfs_unlock_and_release_request(req);

fs/nfs/pagelist.c

@@ -514,26 +514,29 @@ static void nfs_page_assign_page(struct nfs_page *req, struct page *page)
 }
 
 /**
- * nfs_create_request - Create an NFS read/write request.
+ * nfs_page_create_from_page - Create an NFS read/write request.
  * @ctx: open context to use
  * @page: page to write
- * @offset: starting offset within the page for the write
+ * @pgbase: starting offset within the page for the write
+ * @offset: file offset for the write
  * @count: number of bytes to read/write
  *
  * The page must be locked by the caller. This makes sure we never
  * create two different requests for the same page.
  * User should ensure it is safe to sleep in this function.
  */
-struct nfs_page *
-nfs_create_request(struct nfs_open_context *ctx, struct page *page,
-		   unsigned int offset, unsigned int count)
+struct nfs_page *nfs_page_create_from_page(struct nfs_open_context *ctx,
+					   struct page *page,
+					   unsigned int pgbase, loff_t offset,
+					   unsigned int count)
 {
 	struct nfs_lock_context *l_ctx = nfs_get_lock_context(ctx);
 	struct nfs_page *ret;
 
 	if (IS_ERR(l_ctx))
 		return ERR_CAST(l_ctx);
-	ret = nfs_page_create(l_ctx, offset, page_index(page), offset, count);
+	ret = nfs_page_create(l_ctx, pgbase, offset >> PAGE_SHIFT,
+			      offset_in_page(offset), count);
 	if (!IS_ERR(ret)) {
 		nfs_page_assign_page(ret, page);
 		nfs_page_group_init(ret, NULL);

include/linux/nfs_page.h

@@ -121,10 +121,11 @@ struct nfs_pageio_descriptor {
 
 #define NFS_WBACK_BUSY(req)	(test_bit(PG_BUSY,&(req)->wb_flags))
 
-extern	struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
-					    struct page *page,
-					    unsigned int offset,
-					    unsigned int count);
+extern struct nfs_page *nfs_page_create_from_page(struct nfs_open_context *ctx,
+						  struct page *page,
+						  unsigned int pgbase,
+						  loff_t offset,
+						  unsigned int count);
 extern struct nfs_page *nfs_page_create_from_folio(struct nfs_open_context *ctx,
 						   struct folio *folio,
 						   unsigned int offset,