From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752426AbeDLKIK (ORCPT ); Thu, 12 Apr 2018 06:08:10 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:59934 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751854AbeDLKII (ORCPT ); Thu, 12 Apr 2018 06:08:08 -0400 Date: Thu, 12 Apr 2018 18:07:52 +0800 From: Ming Lei To: Wakko Warner Cc: Bart Van Assche , "linux-scsi@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "richard.weinberger@gmail.com" , "linux-block@vger.kernel.org" Subject: Re: 4.15.14 crash with iscsi target and dvd Message-ID: <20180412100751.GB4697@ming.t460p> References: <595a10cfb387e6b2ab4d2053b84fed9b3da9e079.camel@wdc.com> <20180406014644.GA16112@animx.eu.org> <20180406020651.GB16112@animx.eu.org> <20180407165335.GA2515@animx.eu.org> <1ff8d234cc565ba9701ce31899fca5faa597e050.camel@wdc.com> <20180408160254.GA22869@animx.eu.org> <20180409233436.GC6450@ming.t460p> <20180411004525.GA9107@animx.eu.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180411004525.GA9107@animx.eu.org> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 10, 2018 at 08:45:25PM -0400, Wakko Warner wrote: > Ming Lei wrote: > > Sure, thanks for your sharing. > > > > Wakko, could you test the following patch and see if there is any > > difference? > > > > -- > > diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c > > index 0d99b242e82e..6147178f1f37 100644 > > --- a/drivers/target/target_core_pscsi.c > > +++ b/drivers/target/target_core_pscsi.c > > @@ -888,7 +888,7 @@ pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, > > if (len > 0 && data_len > 0) { > > bytes = min_t(unsigned int, len, PAGE_SIZE - off); > > bytes = min(bytes, data_len); > > - > > + new_bio: > > if (!bio) { > > nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages); > > nr_pages -= nr_vecs; > > @@ -931,6 +931,7 @@ pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, > > * be allocated with pscsi_get_bio() above. > > */ > > bio = NULL; > > + goto new_bio; > > } > > > > data_len -= bytes; > > Sorry for the delay. I reverted my change, added this one. I didn't > reboot, I just unloaded and loaded this one. > Note: /dev/sr1 as seen from the initiator is /dev/sr0 (physical disc) on the > target. > > Doesn't crash, however on the initiator I see this: > [9273849.707777] ISO 9660 Extensions: RRIP_1991A > [9273863.359718] scsi_io_completion: 13 callbacks suppressed > [9273863.359788] sr 26:0:0:0: [sr1] tag#1 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=0x08 > [9273863.359909] sr 26:0:0:0: [sr1] tag#1 Sense Key : 0x2 [current] > [9273863.359974] sr 26:0:0:0: [sr1] tag#1 ASC=0x8 ASCQ=0x0 > [9273863.360036] sr 26:0:0:0: [sr1] tag#1 CDB: opcode=0x28 28 00 00 22 f6 96 00 00 80 00 > [9273863.360116] blk_update_request: 13 callbacks suppressed > [9273863.360177] blk_update_request: I/O error, dev sr1, sector 9165400 > [9273875.864648] sr 26:0:0:0: [sr1] tag#1 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=0x08 > [9273875.864738] sr 26:0:0:0: [sr1] tag#1 Sense Key : 0x2 [current] > [9273875.864801] sr 26:0:0:0: [sr1] tag#1 ASC=0x8 ASCQ=0x0 > [9273875.864890] sr 26:0:0:0: [sr1] tag#1 CDB: opcode=0x28 28 00 00 22 f7 16 00 00 80 00 > [9273875.864971] blk_update_request: I/O error, dev sr1, sector 9165912 > > To cause this, I mounted the dvd as seen in the first line and ran this > command: find /cdrom2 -type f | xargs -tn1 cat > /dev/null > I did some various tests. Each test was done after umount and mount to > clear the cache. > cat > /dev/null causes the message. > dd if= of=/dev/null bs=2048 doesn't > using bs=4096 doesn't > using bs=64k doesn't > using bs=128k does > cat uses a blocksize of 128k. > > The following was done without being mounted. > ddrescue -f -f /dev/sr1 /dev/null > doesn't cause the message > dd if=/dev/sr1 of=/dev/null bs=128k > doesn't cause the message > using bs=256k causes the message once: > [9275916.857409] sr 27:0:0:0: [sr1] tag#0 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=0x08 > [9275916.857482] sr 27:0:0:0: [sr1] tag#0 Sense Key : 0x2 [current] > [9275916.857520] sr 27:0:0:0: [sr1] tag#0 ASC=0x8 ASCQ=0x0 > [9275916.857556] sr 27:0:0:0: [sr1] tag#0 CDB: opcode=0x28 28 00 00 00 00 00 00 00 80 00 > [9275916.857614] blk_update_request: I/O error, dev sr1, sector 0 > > If I access the disc from the target natively either by mounting and > accessing files or working with the device directly (ie dd) no errors are > logged on the target. OK, thanks for your test. Could you test the following patch and see if there is still the failure message? diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c index 0d99b242e82e..6137287b52fb 100644 --- a/drivers/target/target_core_pscsi.c +++ b/drivers/target/target_core_pscsi.c @@ -913,9 +913,11 @@ pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, rc = bio_add_pc_page(pdv->pdv_sd->request_queue, bio, page, bytes, off); + if (rc != bytes) + goto fail; pr_debug("PSCSI: bio->bi_vcnt: %d nr_vecs: %d\n", bio_segments(bio), nr_vecs); - if (rc != bytes) { + if (/*rc != bytes*/0) { pr_debug("PSCSI: Reached bio->bi_vcnt max:" " %d i: %d bio: %p, allocating another" " bio\n", bio->bi_vcnt, i, bio); -- Ming