staging: lustre: llite: Change readdir BRW metrics

To simplify the code, change the metrics from bytes to pages.
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5034
Reviewed-on: http://review.whamcloud.com/10275Reviewed-by: wangdi <di.wang@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/llite/dir.c

@@ -148,7 +148,7 @@ static int ll_dir_filler(void *_hash, struct page *page0)
 	struct page **page_pool;
 	struct page *page;
 	struct lu_dirpage *dp;
-	int max_pages = ll_i2sbi(inode)->ll_md_brw_size >> PAGE_SHIFT;
+	int max_pages = ll_i2sbi(inode)->ll_md_brw_pages;
 	int nrdpgs = 0; /* number of pages read actually */
 	int npages;
 	int i;

drivers/staging/lustre/lustre/llite/llite_internal.h

@@ -474,7 +474,7 @@ struct ll_sb_info {
 	unsigned int	      ll_namelen;
 	struct file_operations   *ll_fop;
 
-	unsigned int	      ll_md_brw_size; /* used by readdir */
+	unsigned int		  ll_md_brw_pages; /* readdir pages per RPC */
 
 	struct lu_site	   *ll_site;
 	struct cl_device	 *ll_cl;

drivers/staging/lustre/lustre/llite/llite_lib.c

@@ -319,9 +319,9 @@ static int client_common_fill_super(struct super_block *sb, char *md, char *dt,
 		sbi->ll_flags |= LL_SBI_64BIT_HASH;
 
 	if (data->ocd_connect_flags & OBD_CONNECT_BRW_SIZE)
-		sbi->ll_md_brw_size = data->ocd_brw_size;
+		sbi->ll_md_brw_pages = data->ocd_brw_size >> PAGE_SHIFT;
 	else
-		sbi->ll_md_brw_size = PAGE_SIZE;
+		sbi->ll_md_brw_pages = 1;
 
 	if (data->ocd_connect_flags & OBD_CONNECT_LAYOUTLOCK)
 		sbi->ll_flags |= LL_SBI_LAYOUT_LOCK;