ext4: mballoc: Remove useless setting of ac_criteria

There will be changes coming in future patches which will introduce a new
criteria for block allocation. This removes the useless setting of ac_criteria.
AFAIU, this might be only used to differentiate between whether a preallocated
blocks was allocated or was regular allocator called for allocating blocks.
Hence this also adds the debug prints to identify what type of block allocation
was done in ext4_mb_show_ac().
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/1dbae05617519cb6202f1b299c9d1be3e7cda763.1685449706.git.ojaswin@linux.ibm.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/mballoc.c

@@ -4617,7 +4617,6 @@ ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
 			atomic_inc(&tmp_pa->pa_count);
 			ext4_mb_use_inode_pa(ac, tmp_pa);
 			spin_unlock(&tmp_pa->pa_lock);
-			ac->ac_criteria = 10;
 			read_unlock(&ei->i_prealloc_lock);
 			return true;
 		}
@@ -4660,7 +4659,6 @@ ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
 	}
 	if (cpa) {
 		ext4_mb_use_group_pa(ac, cpa);
-		ac->ac_criteria = 20;
 		return true;
 	}
 	return false;
@@ -5434,6 +5432,10 @@ static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
 			(unsigned long)ac->ac_b_ex.fe_logical,
 			(int)ac->ac_criteria);
 	mb_debug(sb, "%u found", ac->ac_found);
+	mb_debug(sb, "used pa: %s, ", ac->ac_pa ? "yes" : "no");
+	if (ac->ac_pa)
+		mb_debug(sb, "pa_type %s\n", ac->ac_pa->pa_type == MB_GROUP_PA ?
+			 "group pa" : "inode pa");
 	ext4_mb_show_pa(sb);
 }
 #else