1 files changed, 20 insertions, 17 deletions

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 90f292b520d2..0abf3f331f56 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -64,11 +64,7 @@ const struct file_operations nfs_file_operations = {
 	.write		= do_sync_write,
 	.aio_read	= nfs_file_read,
 	.aio_write	= nfs_file_write,
-#ifdef CONFIG_MMU
 	.mmap		= nfs_file_mmap,
-#else
-	.mmap		= generic_file_mmap,
-#endif
 	.open		= nfs_file_open,
 	.flush		= nfs_file_flush,
 	.release	= nfs_file_release,
@@ -141,9 +137,6 @@ nfs_file_release(struct inode *inode, struct file *filp)
 			dentry->d_parent->d_name.name,
 			dentry->d_name.name);
 
-	/* Ensure that dirty pages are flushed out with the right creds */
-	if (filp->f_mode & FMODE_WRITE)
-		nfs_wb_all(dentry->d_inode);
 	nfs_inc_stats(inode, NFSIOS_VFSRELEASE);
 	return nfs_release(inode, filp);
 }
@@ -235,7 +228,6 @@ nfs_file_flush(struct file *file, fl_owner_t id)
 	struct nfs_open_context *ctx = nfs_file_open_context(file);
 	struct dentry	*dentry = file->f_path.dentry;
 	struct inode	*inode = dentry->d_inode;
-	int		status;
 
 	dprintk("NFS: flush(%s/%s)\n",
 			dentry->d_parent->d_name.name,
@@ -245,11 +237,8 @@ nfs_file_flush(struct file *file, fl_owner_t id)
 		return 0;
 	nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
 
-	/* Ensure that data+attribute caches are up to date after close() */
-	status = nfs_do_fsync(ctx, inode);
-	if (!status)
-		nfs_revalidate_inode(NFS_SERVER(inode), inode);
-	return status;
+	/* Flush writes to the server and return any errors */
+	return nfs_do_fsync(ctx, inode);
 }
 
 static ssize_t
@@ -304,11 +293,13 @@ nfs_file_mmap(struct file * file, struct vm_area_struct * vma)
 	dprintk("NFS: mmap(%s/%s)\n",
 		dentry->d_parent->d_name.name, dentry->d_name.name);
 
-	status = nfs_revalidate_mapping(inode, file->f_mapping);
+	/* Note: generic_file_mmap() returns ENOSYS on nommu systems
+	 *       so we call that before revalidating the mapping
+	 */
+	status = generic_file_mmap(file, vma);
 	if (!status) {
 		vma->vm_ops = &nfs_file_vm_ops;
-		vma->vm_flags |= VM_CAN_NONLINEAR;
-		file_accessed(file);
+		status = nfs_revalidate_mapping(inode, file->f_mapping);
 	}
 	return status;
 }
@@ -354,6 +345,15 @@ static int nfs_write_begin(struct file *file, struct address_space *mapping,
 		file->f_path.dentry->d_name.name,
 		mapping->host->i_ino, len, (long long) pos);
 
+	/*
+	 * Prevent starvation issues if someone is doing a consistency
+	 * sync-to-disk
+	 */
+	ret = wait_on_bit(&NFS_I(mapping->host)->flags, NFS_INO_FLUSHING,
+			nfs_wait_bit_killable, TASK_KILLABLE);
+	if (ret)
+		return ret;
+
 	page = grab_cache_page_write_begin(mapping, index, flags);
 	if (!page)
 		return -ENOMEM;
@@ -451,8 +451,9 @@ const struct address_space_operations nfs_file_aops = {
 	.launder_page = nfs_launder_page,
 };
 
-static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct page *page)
+static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
+	struct page *page = vmf->page;
 	struct file *filp = vma->vm_file;
 	struct dentry *dentry = filp->f_path.dentry;
 	unsigned pagelen;
@@ -483,6 +484,8 @@ static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct page *page)
 		ret = pagelen;
 out_unlock:
 	unlock_page(page);
+	if (ret)
+		ret = VM_FAULT_SIGBUS;
 	return ret;
 }