On Wed, 30 Jun 2010 20:55:09 +0900 FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> wrote: > On Mon, 28 Jun 2010 17:25:36 +0200 > Christoph Hellwig <hch@xxxxxx> wrote: > > > On Mon, Jun 28, 2010 at 05:14:28PM +0900, FUJITA Tomonori wrote: > > > > While I see the problems with leaking ressources in that case I still > > > > can't quite explain the hang I see. > > > > > > Any way to reproduce the hang without ssd drives? > > > > Actually the SSDs don't fully hang, they just causes lots of I/O errors > > and hit the error handler hard. The hard hang is when running under > > qemu. Apply the patch below, then create an if=scsi drive that resides > > on an XFS filesystem, and you'll have scsi TP support in the guest: > > Ok, I figured out what's wrong. > > As I suspected, it's due to the partial completion. > > qemu scsi driver tells that the WRITE_SAME command was successful but > somehow the command has resid. So we retry it again and again (and > leak some memory). > > I don't know yet why qemu scsi driver is broken. Maybe there is a bug > in it or converting discard to FS sends broken commands to the driver. looks like your qemu WRITE_SAME patch isn't completed :) You implement WRITE_SAME as if it doesn't do any data transfer. So qemu scsi driver gets resid. The reason why WRITE_SAME works now is that scsi-ml doesn't care about resid with PC commands but it cares with FS commands. I confirmed that qemu scsi driver gets the identical command with both PC and FS commands and qemu calls xfsctl. > I've put a patch to complete discard command in the all-or-nothing > manner: > > git://git.kernel.org/pub/scm/linux/kernel/git/tomo/linux-2.6-misc.git discard Seems that I finished discard FS conversion. I'll update it on the top of James' uprep patchset soon. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
