ext4: extent macros cleanup

Use the EXT_LAST_INDEX macro; that's what it's there for.

Clean up ext4_ext_ext_grow_indepth() so the correct EXT_FIRST_INDEX or
EXT_FIRST_MACRO is used as necessary.  The two macros are equivalent, so
the C will collapse the if statement out, but it makes the code much
more readable.

Signed-off-by: Dmitry Monakhov <[email protected]>
Acked-by: Alex Tomas <[email protected]>
Signed-off-by: Dave Kleikamp <[email protected]>
Singed-off-by: Mingming Cao <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>

Author: Dmitry Monakhov

fs/ext4/extents.c

@@ -376,7 +376,7 @@ ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, int bloc
 	ext_debug("binsearch for %d(idx):  ", block);
 
 	l = EXT_FIRST_INDEX(eh) + 1;
-	r = EXT_FIRST_INDEX(eh) + le16_to_cpu(eh->eh_entries) - 1;
+	r = EXT_LAST_INDEX(eh);
 	while (l <= r) {
 		m = l + (r - l) / 2;
 		if (block < le32_to_cpu(m->ei_block))
@@ -441,7 +441,7 @@ ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block)
 	ext_debug("binsearch for %d:  ", block);
 
 	l = EXT_FIRST_EXTENT(eh) + 1;
-	r = EXT_FIRST_EXTENT(eh) + le16_to_cpu(eh->eh_entries) - 1;
+	r = EXT_LAST_EXTENT(eh);
 
 	while (l <= r) {
 		m = l + (r - l) / 2;
@@ -924,8 +924,13 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
 	curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode));
 	curp->p_hdr->eh_entries = cpu_to_le16(1);
 	curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr);
-	/* FIXME: it works, but actually path[0] can be index */
-	curp->p_idx->ei_block = EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block;
+
+	if (path[0].p_hdr->eh_depth)
+		curp->p_idx->ei_block =
+			EXT_FIRST_INDEX(path[0].p_hdr)->ei_block;
+	else
+		curp->p_idx->ei_block =
+			EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block;
 	ext4_idx_store_pblock(curp->p_idx, newblock);
 
 	neh = ext_inode_hdr(inode);