On Tue, Sep 06, 2016 at 04:49:17PM +0800, wang.guang55@xxxxxxxxxx wrote: > ext4: bugfix for mmaped pages in mpage_release_unused_pages() > > Pages clear buffers after ext4 delayed block allocation failed, > However, it does not clean its pte_dirty flag. > if the pages unmap ,in cording to the pte_dirty , > unmap_page_range may try to call __set_page_dirty, > > which may lead to the bugon at > mpage_prepare_extent_to_map:head = page_buffers(page);. > > This patch just call clear_page_dirty_for_io to clean pte_dirty > at mpage_release_unused_pages for pages mmaped. > > > Steps to reproduce the bug: > （1） mmap a file in ext4 > addr = (char *)mmap(NULL, 4096, > PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); > memset(addr, 'i', 4096); > （2） return EIO at > ext4_writepages->mpage_map_and_submit_extent->mpage_map_one_extent > Cause the log: > ext4_msg(sb, KERN_CRIT, > "Delayed block allocation failed for " > "inode %lu at logical offset %llu with" > " max blocks %u with error %d", > inode->i_ino, > (unsigned long long)map->m_lblk, > (unsigned)map->m_len, -err); > > (3）Unmap the addr cause warning at > __set_page_dirty:WARN_ON_ONCE(warn && !PageUptodate(page)); > (4) wait for a minute,then bugon happen. > > Signed-off-by: wangguang <wangguang03@xxxxxxx> Thanks, applied. Apologies for the delay. - Ted -- 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
