Hello, On Mon, Aug 24, 2015 at 11:09:27PM +0200, Jan Kara wrote: > It is inefficient, yes. But note that 'writeback' and 'dirty' states are > completely independent. Page can be in any of the !dirty & !writeback, That isn't true for pages being dirtied through set_page_dirty(). It's guaranteed that a dirty inode remains on one of the b_* lists till there's no dirty page and writeback is complete. > dirty & !writeback, !dirty & writeback, dirty & writeback states. So mixing > tracking of writeback and dirty state of an inode just makes the code even > messier. I'm curious where and why they would deviate. Can you give me some examples? AFAICS, anything which uses the usual set_page_dirty() path shouldn't do that. > > > a list to track inodes with pages under writeback but they clashed with > > > your patch series and they didn't get rebased yet AFAIR. > > > > Wouldn't it make more sense to simply put them on one of the existing > > b_* lists? > > Logically it just doesn't make sense because as I wrote above dirty and > writeback states are completely independent. Also you'd have to detect & > skip inodes that don't really have any dirty pages to write and all the > detection of "is there any data to write" would get more complicated. A > separate list for inodes under writeback as Josef did is IMO the cleanest > solution. Given that the usual code path tracks dirty and writeback together, I don't think it's nonsensical; however, I'm more curious how common writeback w/o dirtying case is. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
