On Fri, 2009-04-24 at 09:33 +0200, Miklos Szeredi wrote: > On Fri, 24 Apr 2009, Miklos Szeredi wrote: > > Hmm, I guess this is a bit nasty: the VM promises filesystems that > > ->page_mkwrite() will be called when the page is dirtied through a > > mapping, _almost_ all of the time. Except when munmap happens to race > > with clear_page_dirty_for_io(). > > > > I don't have any ideas how this could be fixed, CC-ing linux-mm... > > On second thought, we could possibly just ignore the dirty bit in that > case. Trying to write to a mapping _during_ munmap() will have pretty > undefined results, I don't think any sane application out there should > rely on the results of this. > > But how knows, the world is a weird place... It does happen in practice, btrfs has fallback code that triggers the page_mkwrite when it finds a dirty page that wasn't dirtied with help from the FS. I'd love to get rid of the fallback ;) -chris -- 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
