svn commit: r256560 - in projects/camlock/sys: cddl/contrib/opensolaris/uts/common/fs/zfs geom sys

[Alexander Motin]

Author: mav
Date: Tue Oct 15 21:04:18 2013
New Revision: 256560
URL: http://svnweb.freebsd.org/changeset/base/256560

Log:
  Introduce THREAD_CAN_SLEEP() to check whether current thread is allowed to
  sleep by checking ((curthread)->td_no_sleeping == 0).  Use that to find out
  whether GEOM and classes code can sleep.  Previous check for one of GEOM
  threads was insufficient because request can be sent from other unrelated
  request bio_done() method called at interrupt thread, where sleeping is
  prohibited.

Modified:
  projects/camlock/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c
  projects/camlock/sys/geom/geom_io.c
  projects/camlock/sys/sys/proc.h

Modified: projects/camlock/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c
==============================================================================
--- projects/camlock/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c	Tue Oct 15 21:02:02 2013	(r256559)
+++ projects/camlock/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c	Tue Oct 15 21:04:18 2013	(r256560)
@@ -2261,14 +2261,14 @@ zvol_geom_start(struct bio *bp)
 	ASSERT(zv != NULL);
 	switch (bp->bio_cmd) {
 	case BIO_FLUSH:
-		if (g_is_geom_thread(curthread))
+		if (!THREAD_CAN_SLEEP())
 			goto enqueue;
 		zil_commit(zv->zv_zilog, ZVOL_OBJ);
 		g_io_deliver(bp, 0);
 		break;
 	case BIO_READ:
 	case BIO_WRITE:
-		if (g_is_geom_thread(curthread))
+		if (!THREAD_CAN_SLEEP())
 			goto enqueue;
 		zvol_strategy(bp);
 		break;

Modified: projects/camlock/sys/geom/geom_io.c
==============================================================================
--- projects/camlock/sys/geom/geom_io.c	Tue Oct 15 21:02:02 2013	(r256559)
+++ projects/camlock/sys/geom/geom_io.c	Tue Oct 15 21:04:18 2013	(r256560)
@@ -518,7 +518,9 @@ g_io_request(struct bio *bp, struct g_co
 #ifdef GET_STACK_USAGE
 	direct = (cp->flags & G_CF_DIRECT_SEND) &&
 		 (pp->flags & G_PF_DIRECT_RECEIVE) &&
-		 !g_is_geom_thread(curthread);
+		 !g_is_geom_thread(curthread) &&
+		 (((pp->flags & G_PF_ACCEPT_UNMAPPED) == 0 &&
+		   (bp->bio_flags & BIO_UNMAPPED) != 0) || THREAD_CAN_SLEEP());
 	if (direct) {
 		/* Block direct execution if less then half of stack left. */
 		size_t	st, su;

Modified: projects/camlock/sys/sys/proc.h
==============================================================================
--- projects/camlock/sys/sys/proc.h	Tue Oct 15 21:02:02 2013	(r256559)
+++ projects/camlock/sys/sys/proc.h	Tue Oct 15 21:04:18 2013	(r256560)
@@ -793,6 +793,8 @@ extern pid_t pid_max;
 
 #define	THREAD_SLEEPING_OK()		((curthread)->td_no_sleeping--)
 
+#define	THREAD_CAN_SLEEP()		((curthread)->td_no_sleeping == 0)
+
 #define	PIDHASH(pid)	(&pidhashtbl[(pid) & pidhash])
 extern LIST_HEAD(pidhashhead, proc) *pidhashtbl;
 extern u_long pidhash;