Re: [Lsf] IO less throttling and cgroup aware writeback

Christoph Hellwig
2011-04-07T20:33:15Z

On Thu, Apr 07, 2011 at 03:24:24PM -0400, Vivek Goyal wrote:
> IIUC, so first we need to fix existing code where we seem to be moving
> any inode on bdi writeback list based on I_DIRTY flag.

I_DIRTY is a set of flags. Inodes are on the dirty list if any of
the flags is set.

> BTW, what's the difference between I_DIRTY_DATASYNC and I_DIRTY_PAGES? To
> me both seem to mean that data needs to be written back and not the
> inode itself.

I_DIRTY_PAGES means dirty data (pages)
I_DIRTY_DATASYNC means dirty metadata which needs to be written for fdatasync
I_DIRTY_SYNC means dirty metadata which only needs to be written for fsync