Re: [PATCH 04/16] GFS2: Daemons and address space operations

[Wendy Cheng <wcheng@redhat.com>]

Steven Whitehouse wrote

>+static int gfs2_writepage(struct page *page, struct writeback_control *wbc)
>+{
>+	struct inode *inode = page->mapping->host;
>+	struct gfs2_inode *ip = page->mapping->host->u.generic_ip;
>+	struct gfs2_sbd *sdp = ip->i_sbd;
>+	loff_t i_size = i_size_read(inode);
>+	pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
>+	unsigned offset;
>+	int error;
>+	int done_trans = 0;
>+
>+	if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl))) {
>+		unlock_page(page);
>+		return -EIO;
>+	}
>+	if (current->journal_info)
>+		goto out_ignore;
>+
>+	/* Is the page fully outside i_size? (truncate in progress) */
>+        offset = i_size & (PAGE_CACHE_SIZE-1);
>+	if (page->index >= end_index+1 || !offset) {
>+		page->mapping->a_ops->invalidatepage(page, 0);
>+		unlock_page(page);
>+		return 0; /* don't care */
>+	}
>
>  
>
Will above "|| !offset" unconditionally drop the page if the file size 
happens to be multiples of PAGE_CACHE_SIZE ?  Maybe this truncate 
handling should be removed to let block_write_full_page() handle all the 
cases ?

>+	error = block_write_full_page(page, get_block_noalloc, wbc);
>+	if (done_trans)
>+		gfs2_trans_end(sdp);
>+	gfs2_meta_cache_flush(ip);
>+	return error;
>+
>+out_ignore:
>+	redirty_page_for_writepage(wbc, page);
>+	unlock_page(page);
>+	return 0;
>+}
>+
>  
>
-- Wendy