ext4: remove do_blk_alloc()

The convenience function do_blk_alloc() is a static function with only
one caller, so fold it into ext4_new_meta_blocks() to simplify the
code and to make it easier to understand.

To save more stack space, if count is a null pointer in
ext4_new_meta_blocks() assume that caller wanted a single block (and
if there is an error, no blocks were allocated).
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

fs/ext4/balloc.c

@@ -666,59 +666,40 @@ int ext4_should_retry_alloc(struct super_block *sb, int *retries)
 	return jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal);
 }
 
-#define EXT4_META_BLOCK 0x1
-
-static ext4_fsblk_t do_blk_alloc(handle_t *handle, struct inode *inode,
-				ext4_lblk_t iblock, ext4_fsblk_t goal,
-				unsigned long *count, int *errp, int flags)
-{
-	struct ext4_allocation_request ar;
-	ext4_fsblk_t ret;
-
-	memset(&ar, 0, sizeof(ar));
-	/* Fill with neighbour allocated blocks */
-
-	ar.inode = inode;
-	ar.goal = goal;
-	ar.len = *count;
-	ar.logical = iblock;
-
-	if (S_ISREG(inode->i_mode) && !(flags & EXT4_META_BLOCK))
-		/* enable in-core preallocation for data block allocation */
-		ar.flags = EXT4_MB_HINT_DATA;
-	else
-		/* disable in-core preallocation for non-regular files */
-		ar.flags = 0;
-
-	ret = ext4_mb_new_blocks(handle, &ar, errp);
-	*count = ar.len;
-	return ret;
-}
-
 /*
  * ext4_new_meta_blocks() -- allocate block for meta data (indexing) blocks
  *
  * @handle:             handle to this transaction
  * @inode:              file inode
  * @goal:               given target block(filesystem wide)
- * @count:		total number of blocks need
+ * @count:		pointer to total number of blocks needed
  * @errp:               error code
  *
- * Return 1st allocated block numberon success, *count stores total account
+ * Return 1st allocated block number on success, *count stores total account
  * error stores in errp pointer
  */
 ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
 		ext4_fsblk_t goal, unsigned long *count, int *errp)
 {
+	struct ext4_allocation_request ar;
 	ext4_fsblk_t ret;
-	ret = do_blk_alloc(handle, inode, 0, goal,
-				count, errp, EXT4_META_BLOCK);
+
+	memset(&ar, 0, sizeof(ar));
+	/* Fill with neighbour allocated blocks */
+	ar.inode = inode;
+	ar.goal = goal;
+	ar.len = count ? *count : 1;
+
+	ret = ext4_mb_new_blocks(handle, &ar, errp);
+	if (count)
+		*count = ar.len;
+
 	/*
 	 * Account for the allocated meta blocks
 	 */
 	if (!(*errp) && EXT4_I(inode)->i_delalloc_reserved_flag) {
 		spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
-		EXT4_I(inode)->i_allocated_meta_blocks += *count;
+		EXT4_I(inode)->i_allocated_meta_blocks += ar.len;
 		spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
 	}
 	return ret;

fs/ext4/extents.c

@@ -189,10 +189,9 @@ ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
 			struct ext4_extent *ex, int *err)
 {
 	ext4_fsblk_t goal, newblock;
-	unsigned long count = 1;
 
 	goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
-	newblock = ext4_new_meta_blocks(handle, inode, goal, &count, err);
+	newblock = ext4_new_meta_blocks(handle, inode, goal, NULL, err);
 	return newblock;
 }
 

fs/ext4/xattr.c

@@ -689,7 +689,6 @@ ext4_xattr_block_set(handle_t *handle, struct inode *inode,
 		     struct ext4_xattr_info *i,
 		     struct ext4_xattr_block_find *bs)
 {
-	unsigned long count = 1;
 	struct super_block *sb = inode->i_sb;
 	struct buffer_head *new_bh = NULL;
 	struct ext4_xattr_search *s = &bs->s;
@@ -812,7 +811,7 @@ ext4_xattr_block_set(handle_t *handle, struct inode *inode,
 			ext4_fsblk_t goal = ext4_group_first_block_no(sb,
 						EXT4_I(inode)->i_block_group);
 			ext4_fsblk_t block = ext4_new_meta_blocks(handle, inode,
-						  goal, &count, &error);
+						  goal, NULL, &error);
 			if (error)
 				goto cleanup;
 			ea_idebug(inode, "creating block %d", block);