From owner-svn-src-all@freebsd.org Tue May 15 21:25:36 2018 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id AFDB2EB039E; Tue, 15 May 2018 21:25:36 +0000 (UTC) (envelope-from imp@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 5E79681EBB; Tue, 15 May 2018 21:25:36 +0000 (UTC) (envelope-from imp@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 3F1C310FA2; Tue, 15 May 2018 21:25:36 +0000 (UTC) (envelope-from imp@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id w4FLPa9G006473; Tue, 15 May 2018 21:25:36 GMT (envelope-from imp@FreeBSD.org) Received: (from imp@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id w4FLPajh006472; Tue, 15 May 2018 21:25:36 GMT (envelope-from imp@FreeBSD.org) Message-Id: <201805152125.w4FLPajh006472@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: imp set sender to imp@FreeBSD.org using -f From: Warner Losh Date: Tue, 15 May 2018 21:25:36 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r333648 - head/sys/cam/scsi X-SVN-Group: head X-SVN-Commit-Author: imp X-SVN-Commit-Paths: head/sys/cam/scsi X-SVN-Commit-Revision: 333648 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 15 May 2018 21:25:36 -0000 Author: imp Date: Tue May 15 21:25:35 2018 New Revision: 333648 URL: https://svnweb.freebsd.org/changeset/base/333648 Log: Hold the reference count until the CCB is released When a disk disappears and the periph is invalidated, any I/Os that are pending with the controller can cause a crash when they complete. Move to holding the softc reference count taken in dastart() until the I/O is complete rather than only until xpt_action() returns. (This approach was suggested by Ken Merry.) Sponsored by: Netflix Submitted by: Chuck Silvers Differential Revision: https://reviews.freebsd.org/D15435 Modified: head/sys/cam/scsi/scsi_da.c Modified: head/sys/cam/scsi/scsi_da.c ============================================================================== --- head/sys/cam/scsi/scsi_da.c Tue May 15 21:15:09 2018 (r333647) +++ head/sys/cam/scsi/scsi_da.c Tue May 15 21:25:35 2018 (r333648) @@ -3300,7 +3300,6 @@ out: cam_periph_unlock(periph); xpt_action(start_ccb); cam_periph_lock(periph); - softc->refcount--; /* May have more work to do, so ensure we stay scheduled */ daschedule(periph); @@ -4443,13 +4442,15 @@ dadone(struct cam_periph *periph, union ccb *done_ccb) softc->flags |= DA_FLAG_WAS_OTAG; /* - * We need to call cam_iosched before we call biodone so that we - * don't measure any activity that happens in the completion - * routine, which in the case of sendfile can be quite - * extensive. + * We need to call cam_iosched before we call biodone so that we don't + * measure any activity that happens in the completion routine, which in + * the case of sendfile can be quite extensive. Release the periph + * refcount taken in dastart() for each CCB. */ cam_iosched_bio_complete(softc->cam_iosched, bp, done_ccb); xpt_release_ccb(done_ccb); + KASSERT(softc->refcount >= 1, ("dadone softc %p refcount %d", softc, softc->refcount)); + softc->refcount--; if (state == DA_CCB_DELETE) { TAILQ_HEAD(, bio) queue;