Hi, On Tue, Feb 05, 2002 at 03:39:34PM +0100, Erik Smit wrote: > On Tue, 2002-02-05 at 15:26, Wietse Venema wrote: > > > > maildir delivery requires that certain file system operations are > > > > atomic and synchronous. > > > > [...] > > > > Translated into ext3 speak that means: the link and unlink operations > > > > are written to the log before the respective system call returns. > > > > > > Excuse my ignorance, but since it has been written to log and the > > > machine would crash before the systemcall returns wouldn't this mean it > > > would be recovered (by journal replaying) during boot? > > > > IFF the information is written to the ON DISK log, then the > > recovery is possible. > > Wasn't that the whole point to journaling filesystems (and chattr +S)? Yes. ext3 will always do this on synchronous directories. Synchronous IO is *always* guaranteed to be persistent on disk on return, and ext3 also makes firm atomicity guarantees about all deletes, renames etc. (Incidentally, ffs does not --- renames across directories are not atomic on ffs.) Cheers, Stephen
