[CIFS] use add_to_page_cache_lru

add_to_page_cache_lru is exported, so it should be used. Benefits over
using a private pagevec: neater code, 128 bytes fewer stack used, percpu
lru ordering is preserved, and finally don't need to flush pagevec
before returning so batching may be shared with other LRU insertions.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Reviewed-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/file.c

@@ -1931,8 +1931,7 @@ int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
 
 
 static void cifs_copy_cache_pages(struct address_space *mapping,
-	struct list_head *pages, int bytes_read, char *data,
-	struct pagevec *plru_pvec)
+	struct list_head *pages, int bytes_read, char *data)
 {
 	struct page *page;
 	char *target;
@@ -1944,7 +1943,7 @@ static void cifs_copy_cache_pages(struct address_space *mapping,
 		page = list_entry(pages->prev, struct page, lru);
 		list_del(&page->lru);
 
-		if (add_to_page_cache(page, mapping, page->index,
+		if (add_to_page_cache_lru(page, mapping, page->index,
 				      GFP_KERNEL)) {
 			page_cache_release(page);
 			cFYI(1, ("Add page cache failed"));
@@ -1970,8 +1969,6 @@ static void cifs_copy_cache_pages(struct address_space *mapping,
 		flush_dcache_page(page);
 		SetPageUptodate(page);
 		unlock_page(page);
-		if (!pagevec_add(plru_pvec, page))
-			__pagevec_lru_add_file(plru_pvec);
 		data += PAGE_CACHE_SIZE;
 	}
 	return;
@@ -1990,7 +1987,6 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
 	unsigned int read_size, i;
 	char *smb_read_data = NULL;
 	struct smb_com_read_rsp *pSMBr;
-	struct pagevec lru_pvec;
 	struct cifsFileInfo *open_file;
 	int buf_type = CIFS_NO_BUFFER;
 
@@ -2004,7 +2000,6 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
 	cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 	pTcon = cifs_sb->tcon;
 
-	pagevec_init(&lru_pvec, 0);
 	cFYI(DBG2, ("rpages: num pages %d", num_pages));
 	for (i = 0; i < num_pages; ) {
 		unsigned contig_pages;
@@ -2073,7 +2068,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
 			pSMBr = (struct smb_com_read_rsp *)smb_read_data;
 			cifs_copy_cache_pages(mapping, page_list, bytes_read,
 				smb_read_data + 4 /* RFC1001 hdr */ +
-				le16_to_cpu(pSMBr->DataOffset), &lru_pvec);
+				le16_to_cpu(pSMBr->DataOffset));
 
 			i +=  bytes_read >> PAGE_CACHE_SHIFT;
 			cifs_stats_bytes_read(pTcon, bytes_read);
@@ -2106,8 +2101,6 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
 		bytes_read = 0;
 	}
 
-	pagevec_lru_add_file(&lru_pvec);
-
 /* need to free smb_read_data buf before exit */
 	if (smb_read_data) {
 		if (buf_type == CIFS_SMALL_BUFFER)