Drop experimental dir_index support.

The htree directory index is a highly desirable feature for research
purposes and was meant to improve performance in our ext2/3 driver.
Unfortunately our implementation has two problems:

- It never really delivered any performance improvement.
- It appears to corrupt the filesystem in undetermined circumstances.

Strictly speaking dir_index is not required for read/write support in
ext2/3 and our limited ext4 support still works fine without it.

Regain stability in the ext2 driver by removing it. We may need it back
(fixed) if we want to support encrypted ext4 support but thanks to the
wonders of version control we can always revert this change and bring it
back.

PR:	191895
PR:	198731
PR:	199309

MFC after:	5 days

1 files changed, 0 insertions, 15 deletions

diff --git a/sys/fs/ext2fs/ext2_extern.h b/sys/fs/ext2fs/ext2_extern.h
index 93bd3f7..f7b7657 100644
--- a/sys/fs/ext2fs/ext2_extern.h
+++ b/sys/fs/ext2fs/ext2_extern.h
@@ -40,15 +40,12 @@
 #define	_FS_EXT2FS_EXT2_EXTERN_H_
 
 struct ext2fs_dinode;
-struct ext2fs_direct_2;
-struct ext2fs_searchslot;
 struct indir;
 struct inode;
 struct mount;
 struct vfsconf;
 struct vnode;
 
-int	ext2_add_entry(struct vnode *, struct ext2fs_direct_2 *);
 int	ext2_alloc(struct inode *, daddr_t, e4fs_daddr_t, int,
 	    struct ucred *, e4fs_daddr_t *);
 int	ext2_balloc(struct inode *,
@@ -86,18 +83,6 @@ int	ext2_dirempty(struct inode *, ino_t, struct ucred *);
 int	ext2_checkpath(struct inode *, struct inode *, struct ucred *);
 int	cg_has_sb(int i);
 int	ext2_inactive(struct vop_inactive_args *);
-int	ext2_htree_add_entry(struct vnode *, struct ext2fs_direct_2 *,
-	    struct componentname *);
-int	ext2_htree_create_index(struct vnode *, struct componentname *,
-	    struct ext2fs_direct_2 *);
-int	ext2_htree_has_idx(struct inode *);
-int	ext2_htree_hash(const char *, int, uint32_t *, int, uint32_t *,
-	    uint32_t *);
-int	ext2_htree_lookup(struct inode *, const char *, int, struct buf **,
-	    int *, doff_t *, doff_t *, doff_t *, struct ext2fs_searchslot *);
-int	ext2_search_dirblock(struct inode *, void *, int *, const char *, int,
-	    int *, doff_t *, doff_t *, doff_t *, struct ext2fs_searchslot *);
-
 
 /* Flags to low-level allocation routines.
  * The low 16-bits are reserved for IO_ flags from vnode.h.