nfs: Provide and use helper functions for marking a page as unstable

Signed-off-by: Tom Haynes <loghyr@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/filelayout/filelayout.c b/fs/nfs/filelayout/filelayout.c
index 7ae1c26..e1e5ea2 100644
--- a/fs/nfs/filelayout/filelayout.c
+++ b/fs/nfs/filelayout/filelayout.c
@@ -1000,13 +1000,8 @@
 	nfs_list_add_request(req, list);
 	cinfo->mds->ncommit++;
 	spin_unlock(cinfo->lock);
-	if (!cinfo->dreq) {
-		inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
-		inc_bdi_stat(inode_to_bdi(page_file_mapping(req->wb_page)->host),
-			     BDI_RECLAIMABLE);
-		__mark_inode_dirty(req->wb_context->dentry->d_inode,
-				   I_DIRTY_DATASYNC);
-	}
+	if (!cinfo->dreq)
+		nfs_mark_page_unstable(req->wb_page);
 }
 
 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c
index c22ecaa..423c2bc 100644
--- a/fs/nfs/flexfilelayout/flexfilelayout.c
+++ b/fs/nfs/flexfilelayout/flexfilelayout.c
@@ -1364,13 +1364,8 @@
 	nfs_list_add_request(req, list);
 	cinfo->mds->ncommit++;
 	spin_unlock(cinfo->lock);
-	if (!cinfo->dreq) {
-		inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
-		inc_bdi_stat(inode_to_bdi(page_file_mapping(req->wb_page)->host),
-			     BDI_RECLAIMABLE);
-		__mark_inode_dirty(req->wb_context->dentry->d_inode,
-				   I_DIRTY_DATASYNC);
-	}
+	if (!cinfo->dreq)
+		nfs_mark_page_unstable(req->wb_page);
 }
 
 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 212b8c8..b802fb3 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -598,6 +598,19 @@
 }
 
 /*
+ * Record the page as unstable and mark its inode as dirty.
+ */
+static inline
+void nfs_mark_page_unstable(struct page *page)
+{
+	struct inode *inode = page_file_mapping(page)->host;
+
+	inc_zone_page_state(page, NR_UNSTABLE_NFS);
+	inc_bdi_stat(inode_to_bdi(inode), BDI_RECLAIMABLE);
+	 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
+}
+
+/*
  * Determine the number of bytes of data the page contains
  */
 static inline
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 88a6d21..76c278a 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -789,13 +789,8 @@
 	nfs_list_add_request(req, dst);
 	cinfo->mds->ncommit++;
 	spin_unlock(cinfo->lock);
-	if (!cinfo->dreq) {
-		inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
-		inc_bdi_stat(inode_to_bdi(page_file_mapping(req->wb_page)->host),
-			     BDI_RECLAIMABLE);
-		__mark_inode_dirty(req->wb_context->dentry->d_inode,
-				   I_DIRTY_DATASYNC);
-	}
+	if (!cinfo->dreq)
+		nfs_mark_page_unstable(req->wb_page);
 }
 EXPORT_SYMBOL_GPL(nfs_request_add_commit_list);