NFS: Clean up writeback code

Now that the VM promises never to recurse back into the filesystem
layer on writeback, remove all the GFP_NOFS references etc from
the generic writeback code.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

fs/nfs/pagelist.c

@@ -77,7 +77,7 @@ void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos)
 static inline struct nfs_page *
 nfs_page_alloc(void)
 {
-	struct nfs_page	*p = kmem_cache_zalloc(nfs_page_cachep, GFP_NOIO);
+	struct nfs_page	*p = kmem_cache_zalloc(nfs_page_cachep, GFP_KERNEL);
 	if (p)
 		INIT_LIST_HEAD(&p->wb_list);
 	return p;
@@ -775,8 +775,6 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
 	if (pagecount <= ARRAY_SIZE(pg_array->page_array))
 		pg_array->pagevec = pg_array->page_array;
 	else {
-		if (hdr->rw_mode == FMODE_WRITE)
-			gfp_flags = GFP_NOIO;
 		pg_array->pagevec = kcalloc(pagecount, sizeof(struct page *), gfp_flags);
 		if (!pg_array->pagevec) {
 			pg_array->npages = 0;
@@ -851,7 +849,7 @@ nfs_pageio_alloc_mirrors(struct nfs_pageio_descriptor *desc,
 	desc->pg_mirrors_dynamic = NULL;
 	if (mirror_count == 1)
 		return desc->pg_mirrors_static;
-	ret = kmalloc_array(mirror_count, sizeof(*ret), GFP_NOFS);
+	ret = kmalloc_array(mirror_count, sizeof(*ret), GFP_KERNEL);
 	if (ret != NULL) {
 		for (i = 0; i < mirror_count; i++)
 			nfs_pageio_mirror_init(&ret[i], desc->pg_bsize);

fs/nfs/pnfs.c

@@ -2468,7 +2468,7 @@ pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
 						   wb_size,
 						   IOMODE_RW,
 						   false,
-						   GFP_NOFS);
+						   GFP_KERNEL);
 		if (IS_ERR(pgio->pg_lseg)) {
 			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 			pgio->pg_lseg = NULL;

fs/nfs/write.c

@@ -103,7 +103,7 @@ EXPORT_SYMBOL_GPL(nfs_commit_free);
 
 static struct nfs_pgio_header *nfs_writehdr_alloc(void)
 {
-	struct nfs_pgio_header *p = mempool_alloc(nfs_wdata_mempool, GFP_NOIO);
+	struct nfs_pgio_header *p = mempool_alloc(nfs_wdata_mempool, GFP_KERNEL);
 
 	memset(p, 0, sizeof(*p));
 	p->rw_mode = FMODE_WRITE;
@@ -721,12 +721,11 @@ int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
 	struct inode *inode = mapping->host;
 	struct nfs_pageio_descriptor pgio;
 	struct nfs_io_completion *ioc;
-	unsigned int pflags = memalloc_nofs_save();
 	int err;
 
 	nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES);
 
-	ioc = nfs_io_completion_alloc(GFP_NOFS);
+	ioc = nfs_io_completion_alloc(GFP_KERNEL);
 	if (ioc)
 		nfs_io_completion_init(ioc, nfs_io_completion_commit, inode);
 
@@ -737,8 +736,6 @@ int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
 	nfs_pageio_complete(&pgio);
 	nfs_io_completion_put(ioc);
 
-	memalloc_nofs_restore(pflags);
-
 	if (err < 0)
 		goto out_err;
 	err = pgio.pg_error;