ocfs2: Add total entry count to dx_root_block

This little bit of extra accounting speeds up ocfs2_empty_dir()
dramatically by allowing us to short-circuit the full directory scan.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/fs/ocfs2/ocfs2_fs.h b/fs/ocfs2/ocfs2_fs.h
index 43da76eff9ae..f7a5201410c8 100644
--- a/fs/ocfs2/ocfs2_fs.h
+++ b/fs/ocfs2/ocfs2_fs.h
@@ -421,6 +421,7 @@ static struct ocfs2_system_inode_info ocfs2_system_inodes[NUM_SYSTEM_INODES] = {
 #define OCFS2_LINK_MAX          32000
 #define OCFS2_DX_LINK_MAX       ((1U << 31) - 1U)
 #define OCFS2_LINKS_HI_SHIFT    16
+#define OCFS2_DX_ENTRIES_MAX    (0xffffffffU)
 
 #define S_SHIFT                 12
 static unsigned char ocfs2_type_by_mode[S_IFMT >> S_SHIFT] = {
@@ -844,7 +845,10 @@ struct ocfs2_dx_root_block {
         __u8            dr_reserved0;
         __le16          dr_reserved1;
         __le64          dr_dir_blkno;           /* Pointer to parent inode */
-        __le64          dr_reserved2;
+        __le32          dr_num_entries;         /* Total number of
+                                                 * names stored in
+                                                 * this directory.*/
+        __le32          dr_reserved2;
         __le64          dr_free_blk;            /* Pointer to head of free
                                                  * unindexed block list. */
         __le64          dr_reserved3[15];