len = PAGE_CACHE_SIZE;
page_bufs = page_buffers(page);
+ /*
+ * We cannot do block allocation or other extent handling in this
+ * function. If there are buffers needing that, we have to redirty
+ * the page. But we may reach here when we do a journal commit via
+ * journal_submit_inode_data_buffers() and in that case we must write
+ * allocated buffers to achieve data=ordered mode guarantees.
+ */
if (ext4_walk_page_buffers(NULL, page_bufs, 0, len, NULL,
ext4_bh_delay_or_unwritten)) {
- /*
- * We don't want to do block allocation, so redirty
- * the page and return. We may reach here when we do
- * a journal commit via journal_submit_inode_data_buffers.
- * We can also reach here via shrink_page_list but it
- * should never be for direct reclaim so warn if that
- * happens
- */
- WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD)) ==
- PF_MEMALLOC);
redirty_page_for_writepage(wbc, page);
- unlock_page(page);
- return 0;
+ if (current->flags & PF_MEMALLOC) {
+ /*
+ * For memory cleaning there's no point in writing only
+ * some buffers. So just bail out. Warn if we came here
+ * from direct reclaim.
+ */
+ WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD))
+ == PF_MEMALLOC);
+ unlock_page(page);
+ return 0;
+ }
}
if (PageChecked(page) && ext4_should_journal_data(inode))