What is wrong with the standard procedure is that once upon a time the standard procedure that everyone knew and coded to was steps 1 through 4, without step 5.

What is wrong with the standard procedure is that once upon a time the standard procedure that everyone knew and coded to was steps 1 through 4, without step 5. Then Linux ext4 people decided that step 5 was necessary, or rather that they could optimize ext4 to delay and lose some writes if you left out step 5. Which lots of people did, and so some people unexpectedly lost data and were unhappy. If we have only a standard procedure and not an actual agreed on standard (whether or not it's a formal one), we are forever vulnerable to the next clever filesystem developer who decides that obviously they can get away with adding a new step 6, or 7, or 8 in some situations, under some interpretation of the POSIX or Single Unix Specification wording, or the Linux manpages, or whatever. (I'm the author of the linked-to blog entry.)