Re: [patch 0/9] writeback data integrity and other fixes (take 3)

Chris Mason
2008-10-29T14:57:45Z

On Wed, 2008-10-29 at 09:32 -0400, Ric Wheeler wrote:
> Jamie Lokier wrote:

> >> Is there anything that particularly makes it a file operation
> >> as opposed to an inode operation?
> >>
> >
> > In principle, is fsync() required to flush all dirty data written
> > through any file descriptor ever, or just dirty data written through
> > the file descriptor used for fsync()?
> >
> > -- Jamie
> > --
> >
> http://www.opengroup.org/onlinepubs/009695399/functions/fsync.html
>
> Is a pointer to what seems to be the official posix spec for this - it
> is definitely per file descriptor, not per file system, etc...
>

Maybe I'm reading Jamie's question wrong, but I think he's saying:

/* open exactly the same file twice */
fd = open("file");
fd2 = open("file");

write(fd, "stuff")
write(fd2, "more stuff")
fsync(fd);

Does the fsync promise "more stuff" will be on disk? I think the answer
should be yes.

-chris