On Wed, 2005-02-16 at 11:43, Dave Kleikamp wrote: > On Wed, 2005-02-16 at 11:28 -0800, Badari Pulavarty wrote: > > On Wed, 2005-02-16 at 11:09, Dave Kleikamp wrote: > > > On Wed, 2005-02-16 at 10:37 -0800, Badari Pulavarty wrote: > > > > > > > Yes. page->private is assumed for the bufferhead usage. Do you really > > > > need for handling page->private for non-bufferhead usage ? > > > > > > For what it's worth, I'm working on some changes to jfs that will use > > > page->private for non-bufferhead usage for metadata, but I won't be > > > using a generic writepage, so it's not an issue for me. > > > > Nope. it would be an issue for you, since jfs uses mpage_writepages() > > which uses the same code - which thinks page->private as bufferhead. > > The patch I am working on will call mpage_writepages() for metadata, but > will use my own writepage() rather than mpage_writepage(), and nothing > in mpage_writepages() will use page->private.
Okay, that will work. Basically, you plan to call mpage_writepages() with NULL as get_block(). Isn't it ? > For normal data, page->private, if used at all, will be bufferheads. Good. > > > > > > > mpage.c already assumes page->private implies bufferheads, so it's not > > > completely generic. Would implementing this as nobh_write_full_page, to > > > complement block_write_full_page, make sense? > > > > I guess, it can be done. So to really deal with this, we need to come > > up with generic writepage/writepages interfaces which doesn't deal > > with bufferheads. > > I'm not sure how useful that would be. Are there any users of a > non-bufferhead page->private that want to call a generic writepage(s)? > In other words, if a generic function is sufficient, you probably > wouldn't be using page->private anyway. This goes back to original question, is there a point in creating new interfaces for writepage & writepages which doesn't assuming page->private. So far, only users are ext2+nobh and JFS. But both of them will not use page->private for anything else other than bufferheads (if at all used). For both of these, the mpage_writepage() I cooked up earlier would be good enough. I guess, we will do it ONLY if someone really needs it. Thanks, Badari - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
