From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benny Halevy Subject: Re: Is sata_nv compatible with async scsi scan? Date: Tue, 21 Apr 2009 15:30:26 +0300 Message-ID: <49EDBC62.5070202@panasas.com> References: <49ED6FD7.3070307@panasas.com> <49ED9FAC.1080303@garzik.org> <20090421112608.GV1926@parisc-linux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20090421112608.GV1926@parisc-linux.org> Sender: linux-scsi-owner@vger.kernel.org To: Matthew Wilcox Cc: Jeff Garzik , Jeff Garzik , lkml , linux-ide@vger.kernel.org, linux-scsi , Arjan van de Ven , Andrew Morton List-Id: linux-ide@vger.kernel.org On Apr. 21, 2009, 14:26 +0300, Matthew Wilcox wrote: > On Tue, Apr 21, 2009 at 06:27:56AM -0400, Jeff Garzik wrote: >> Benny Halevy wrote: >>> Hi Jeff, >>> >>> Since 2.6.29 I'm having intermittent problems with booting kernels. >>> After supposedly waiting for scsi async scan to complete, >>> quite frequently I see errors from the init resume process >>> when it fails to find the swap partition and later the root >>> file system fails to load. >>> >>> A workaround that I found to be helpful is booting the kernel >>> with scsi_mod.scan=sync so I suspect sata_nv has a problem >>> with asynchronous scanning. >> Personally, I think the whole system is broken, so continue to use this >> workaround until it gets fixed upstream. This sounds like some timing >> issues related to waiting for the device probe to finish, something that >> people keep breaking (witness my USB flash drive boot breakage). > > No, it's 4ace92fc112c6069b4fcb95a31d3142d4a43ff2a. > > Specifically, this bit: > > @@ -179,6 +180,8 @@ int scsi_complete_async_scans(void) > spin_unlock(&async_scan_lock); > > kfree(data); > + /* Synchronize async operations globally */ > + async_synchronize_full(); > return 0; > } > > Vegard Nossum has a patch that seems to have been ignored: > > http://marc.info/?l=linux-kernel&m=123920746830420&w=2 > Hmm, it might help somewhat but my test machine still failed to boot 2 out of 5 times with this patch. Benny