Re: ext3-2.4-0.9.4

[Andrew Morton]

Alan Cox wrote:
> 
>...
> > If you have metadata journalling, all you need for this algorithm to
> > work is to have rename() write to the journal before returning.  Is
> > this true for any of the current journalling file systems on Linux?
> 
> Ext3 I believe so, Reiserfs I would assume so but Hans can answer
> definitively

For ext3: this is true if something forces a commit.  Apart from data in
`-o data=writeback' mode, a commit syncs the entire filesystem.
Things which force a commit include:

- completing a write() on an O_SYNC file.
- Performing any metadata operation on a `chattr +S' object
- Performing any metadata operation on an object on a `mount -o sync'
  filesystem.

In `data=journal' or `data=ordered' mode, any of these things will
commit everything to non-volatile storage.

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