On Tue, 14 Nov 2017 16:56:47 -0500 Josef Bacik <josef@xxxxxxxxxxxxxx> wrote: > From: Josef Bacik <jbacik@xxxxxx> > > The only reason we pass in the mapping is to get the inode in order to see if > writeback cgroups is enabled, and even then it only checks the bdi and a super > block flag. balance_dirty_pages() doesn't even use the mapping. Since > balance_dirty_pages*() works on a bdi level, just pass in the bdi and super > block directly so we can avoid using mapping. This will allow us to still use > balance_dirty_pages for dirty metadata pages that are not backed by an > address_mapping. > > ... > > @@ -71,7 +72,8 @@ static int _block2mtd_erase(struct block2mtd_dev *dev, loff_t to, size_t len) > memset(page_address(page), 0xff, PAGE_SIZE); > set_page_dirty(page); > unlock_page(page); > - balance_dirty_pages_ratelimited(mapping); > + balance_dirty_pages_ratelimited(inode_to_bdi(inode), > + inode->i_sb); > break; > } So we do a bunch more work in each caller and we pass two args rather than one. That doesn't make things better! I see that this is enablement for "dirty metadata pages that are not backed by an address_mapping" (address_space) so I look into [7/10] and the changelog doesn't tell me much. So color me confused. What is this patchset actually *for*? Is there some filesystem which has non-address_space-backed metadata? Or will there be so soon? Or what. I think we need a [0/n] email please. One which fully describes the intent of the patchset.
