This generall looks ok, but a few nitpicks below:
> -static void redirty_tail(struct inode *inode, struct bdi_writeback *wb)
> +static void __redirty_tail(struct inode *inode, struct bdi_writeback *wb)
I think redirty_tail_locked would be a more decriptive name, and also
fit other uses in this file (e.g. inode_io_list_move_locked and
inode_io_list_del_locked).
> {
> + assert_spin_locked(&inode->i_lock);
> if (!list_empty(&wb->b_dirty)) {
Nit: I find an empty line after asserts and before the real code starts
nice on the eye.
> break;
> list_move(&inode->i_io_list, &tmp);
> moved++;
> + spin_lock(&inode->i_lock);
> if (flags & EXPIRE_DIRTY_ATIME)
> - set_bit(__I_DIRTY_TIME_EXPIRED, &inode->i_state);
> + inode->i_state |= I_DIRTY_TIME_EXPIRED;
> + inode->i_state |= I_SYNC_QUEUED;
> + spin_unlock(&inode->i_lock);
I wonder if the locking changes should go into a prep patch vs the
actual logic changes related to I_SYNC_QUEUED? That would untangle
the patch quite a bit and make it easier to follow.
> #define I_WB_SWITCH (1 << 13)
> #define I_OVL_INUSE (1 << 14)
> #define I_CREATING (1 << 15)
> +#define I_SYNC_QUEUED (1 << 16)
FYI, this conflicts with the I_DONTCAT addition in mainline now.
