Date: Sat, 1 Sep 2018 16:16:40 +0000 (UTC) From: Edward Tomasz Napierala <trasz@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r338426 - head/sys/cam/ctl Message-ID: <201809011616.w81GGe7g036530@repo.freebsd.org>
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Author: trasz Date: Sat Sep 1 16:16:40 2018 New Revision: 338426 URL: https://svnweb.freebsd.org/changeset/base/338426 Log: Try harder in cfiscsi_offline(). This is believed to be the workaround for the "ctld hanging on reload" problem observed in same cases under high load. I'm not 100% sure it's _the_ fix, as the issue is rather hard to reproduce, but it was tested as part of a larger path and the problem disappeared. It certainly shouldn't break anything. Now, technically, it shouldn't be needed. Quoting mav@, "After ct->ct_online == 0 there should be no new sessions attached to the target. And if you see some problems abbout it, it may either mean that there are some races where single cfiscsi_session_terminate(cs) call may be lost, or as a guess while this thread was sleeping target was reenabbled and redisabled again". Should such race be discovered and properly fixed in the future, than this and the followup two commits can be backed out. PR: 220175 Reported by: Eugene M. Zheganin <emz at norma.perm.ru> Tested by: Eugene M. Zheganin <emz at norma.perm.ru> Discussed with: mav Approved by: re (gjb) MFC after: 2 weeks Sponsored by: playkey.net Modified: head/sys/cam/ctl/ctl_frontend_iscsi.c Modified: head/sys/cam/ctl/ctl_frontend_iscsi.c ============================================================================== --- head/sys/cam/ctl/ctl_frontend_iscsi.c Sat Sep 1 16:13:56 2018 (r338425) +++ head/sys/cam/ctl/ctl_frontend_iscsi.c Sat Sep 1 16:16:40 2018 (r338426) @@ -1447,11 +1447,11 @@ cfiscsi_offline(void *arg) ct->ct_online = 0; online = --softc->online; - TAILQ_FOREACH(cs, &softc->sessions, cs_next) { - if (cs->cs_target == ct) - cfiscsi_session_terminate(cs); - } do { + TAILQ_FOREACH(cs, &softc->sessions, cs_next) { + if (cs->cs_target == ct) + cfiscsi_session_terminate(cs); + } TAILQ_FOREACH(cs, &softc->sessions, cs_next) { if (cs->cs_target == ct) break;
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