On Thu, 2008-08-07 at 12:15 +0900, Hisashi Hifumi wrote: > >/* > > * This is like invalidate_complete_page(), except it ignores the page's > > * refcount. We do this because invalidate_inode_pages2() needs > >stronger > > * invalidation guarantees, and cannot afford to leave pages behind > >because > > * shrink_page_list() has a temp ref on them, or because they're > >transiently > > * sitting in the lru_cache_add() pagevecs. > > */ > > > > > >I am wondering why we need stronger invalidate hurantees for DIO-> > >invalidate_inode_pages_range(),which force the page being removed from > >page cache? In case of bh is busy due to ext3 writeout, > >journal_try_to_free_buffers() could return different error number(EBUSY) > >to try_to_releasepage() (instead of EIO). In that case, could we just > >leave the page in the cache, clean pageuptodate() (to force later buffer > >read to read from disk) and then invalidate_complete_page2() return > >successfully? Any issue with this way? > > My idea is that journal_try_to_free_buffers returns EBUSY if it fails due to > bh busy, and dio write falls back to buffered write. This is easy to fix. > > What about the invalidates done after the DIO has already run non-buffered? -chris -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
