A nasty file corruption bug - fixed

Posted Jan 2, 2007 21:29 UTC (Tue) by flewellyn (subscriber, #5047)
Parent article: A nasty file corruption bug - fixed

I might be naive in asking this, but why are buffer-heads still used at all? Obviously, filesystems were meant to transition away from using them for flushing, so what are they still used for?

Also, I might again be naive in asking, but why not patch all filesystems to not use them for flushing, if doing so is incorrect?

A nasty file corruption bug - fixed

Posted Jan 2, 2007 23:02 UTC (Tue) by dlang (guest, #313) [Link]

at some point you still need a pointer to each disk block of data, and that is what the bh is supposed to be used for (per Linus).

there are several good reasons for not just going in and changeing all filesystems to not use them for flushing

1. not everyone agrees with Linus (Andrew M for example)

2. it would be a very invasive set of changes to the filesystems, which would introduce their own risk of new bugs.

3. many people who agree with Linus that bh should not be used for flushing are also not sure of exactly what should be done to eliminate this (and how much of the new code should be filesystem neutral and how much should be specific to each filesystem)