Date: Fri, 13 Oct 2017 22:40:57 +0000 (UTC) From: John Baldwin <jhb@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r324612 - in stable: 10/sys/ufs/ffs 11/sys/ufs/ffs Message-ID: <201710132240.v9DMev9g045891@repo.freebsd.org>
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Author: jhb Date: Fri Oct 13 22:40:57 2017 New Revision: 324612 URL: https://svnweb.freebsd.org/changeset/base/324612 Log: MFC 324039: Don't defer wakeup()s for completed journal workitems. Normally wakeups() are performed for completed softupdates work items in workitem_free() before the underlying memory is free()'d. complete_jseg() was clearing the "wakeup needed" flag in work items to defer the wakeup until the end of each loop iteration. However, this resulted in the item being free'd before it's address was used with wakeup(). As a result, another part of the kernel could allocate this memory from malloc() and use it as a wait channel for a different "event" with a different lock. This triggered an assertion failure when the lock passed to sleepq_add() did not match the existing lock associated with the sleep queue. Fix this by removing the code to defer the wakeup in complete_jseg() allowing the wakeup to occur slightly earlier in workitem_free() before free() is called. Modified: stable/10/sys/ufs/ffs/ffs_softdep.c Directory Properties: stable/10/ (props changed) Changes in other areas also in this revision: Modified: stable/11/sys/ufs/ffs/ffs_softdep.c Directory Properties: stable/11/ (props changed) Modified: stable/10/sys/ufs/ffs/ffs_softdep.c ============================================================================== --- stable/10/sys/ufs/ffs/ffs_softdep.c Fri Oct 13 21:58:44 2017 (r324611) +++ stable/10/sys/ufs/ffs/ffs_softdep.c Fri Oct 13 22:40:57 2017 (r324612) @@ -3594,15 +3594,13 @@ complete_jseg(jseg) { struct worklist *wk; struct jmvref *jmvref; - int waiting; #ifdef INVARIANTS int i = 0; #endif while ((wk = LIST_FIRST(&jseg->js_entries)) != NULL) { WORKLIST_REMOVE(wk); - waiting = wk->wk_state & IOWAITING; - wk->wk_state &= ~(INPROGRESS | IOWAITING); + wk->wk_state &= ~INPROGRESS; wk->wk_state |= COMPLETE; KASSERT(i++ < jseg->js_cnt, ("handle_written_jseg: overflow %d >= %d", @@ -3643,8 +3641,6 @@ complete_jseg(jseg) TYPENAME(wk->wk_type)); /* NOTREACHED */ } - if (waiting) - wakeup(wk); } /* Release the self reference so the structure may be freed. */ rele_jseg(jseg);
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