On Tue, Jul 09, 2013 at 10:39:36AM +0200, Jan Kara wrote: > On Mon 08-07-13 21:06:58, Guenter Roeck wrote: > > On Mon, Jul 08, 2013 at 11:35:10PM -0400, Theodore Ts'o wrote: > > > On Mon, Jul 08, 2013 at 11:38:29AM -0700, Guenter Roeck wrote: > > > > Hi, > > > > > > > > seen this morning with a brand new top-of-tree kernel (as of last night) plus a > > > > couple of patches I am working on. > > > > > > > > Due to my changes, there is a slight chance that the problem is not due to an > > > > upstream bug, but I think that is quite unlikely (my changes are unrelated > > > > to file system code). > > > > > > > > If there is anything I can help to track this down, please let me know. > > > > > > > > [13071.291013] ------------[ cut here ]------------ > > > > [13071.291021] WARNING: at fs/ext4/inode.c:230 ext4_evict_inode+0x41b/0x510() > > > > > > Hmm, this warning was added by commit 5dc23bdd5: ext4: remove > > > ext4_ioend_wait(). > > > > > > What sort of work load are you running on this machine? Do you know > > > what might have triggered it? > > > > > My nightly kernel builds were running at the time. This is a sequence of git > > clone/checkout operations followed by builds for several targets. > > > > I have the same kernel running on three systems, but this only happened on the > > build machine, and I have not seen it again during the day. > > > > I'll let you know if it happens again tonight. > Thanks for report. I think I see what's going on. I think we completed > bio directly in ext4_end_bio() (as it didn't need unwritten conversion) but > io_end is released only a bit later which can race with ext4_evict_inode() > as: > CPU1 CPU2 > ext4_end_bio() ext4_evict_inode() > ext4_finish_bio() > end_page_writeback(); > truncate_inode_pages() > evict page > WARN_ON(i_ioend_count > 0); > ext4_put_io_end_defer() > ext4_release_io_end() > dec i_ioend_count > > This seems harmless. I'll see if I can easily fix this to make the warning > still useful. If not, I'll just rip out i_ioend_count completely as it's > there only as a sanity check until the new code settles down... > Good to hear that. It did not happen tonight, even though I ran builds on two systems, so it must be quite rare. It would be great if you can Cc: me on any patch. Also, if you have some test software to trigger this condition, let me know and I'll give it a try. Thanks, Guenter -- 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
