Commit bddb53b7 authored by Andreas Gruenbacher's avatar Andreas Gruenbacher
Browse files

gfs2: Get rid of GLF_INVALIDATE_IN_PROGRESS 



Get rid of the GLF_INVALIDATE_IN_PROGRESS flag: it was originally used
to indicate to add_to_queue() that the ->go_sync() and ->go_invalid()
operations were in progress, but as we have established in commit "gfs2:
Fix LM_FLAG_TRY* logic in add_to_queue", add_to_queue() has no need to
know.

Commit d99724c3 describes a race in which GLF_INVALIDATE_IN_PROGRESS
is used to serialize two processes which are both in do_xmote() at the
same time.  That analysis is wrong: the serialization happens via the
GLF_LOCK flag, which ensures that at most one glock operation can be
active at any time.

Fixes: d99724c3 ("gfs2: Close timing window with GLF_INVALIDATE_IN_PROGRESS")
Signed-off-by: default avatarAndreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: default avatarAndrew Price <anprice@redhat.com>
parent 061df28b

fs/gfs2/glock.c

+1 −15
Original line number Diff line number Diff line
@@ -703,17 +703,6 @@ __acquires(&gl->gl_lockref.lock) 


	GLOCK_BUG_ON(gl, gl->gl_state == target);

	GLOCK_BUG_ON(gl, gl->gl_state == gl->gl_target);

	if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) &&

	    glops->go_inval) {

		/*

		 * If another process is already doing the invalidate, let that

		 * finish first.  The glock state machine will get back to this

		 * holder again later.

		 */

		if (test_and_set_bit(GLF_INVALIDATE_IN_PROGRESS,

				     &gl->gl_flags))

			return;

	}

	if (!glops->go_inval || !glops->go_sync)

		goto skip_inval;
@@ -732,7 +721,7 @@ __acquires(&gl->gl_lockref.lock) 
		goto skip_inval;

	}



	if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) {

	if (target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) {

		/*

		 * The call to go_sync should have cleared out the ail list.

		 * If there are still items, we have a problem. We ought to
@@ -747,7 +736,6 @@ __acquires(&gl->gl_lockref.lock) 
			gfs2_dump_glock(NULL, gl, true);

		}

		glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA);

		clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);

	}

	spin_lock(&gl->gl_lockref.lock);
@@ -2316,8 +2304,6 @@ static const char *gflags2str(char *buf, const struct gfs2_glock *gl) 
		*p++ = 'y';

	if (test_bit(GLF_LFLUSH, gflags))

		*p++ = 'f';

	if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags))

		*p++ = 'i';

	if (test_bit(GLF_PENDING_REPLY, gflags))

		*p++ = 'R';

	if (test_bit(GLF_HAVE_REPLY, gflags))

fs/gfs2/incore.h

+0 −1
Original line number Diff line number Diff line
@@ -319,7 +319,6 @@ enum { 
	GLF_DEMOTE_IN_PROGRESS		= 5,

	GLF_DIRTY			= 6,

	GLF_LFLUSH			= 7,

	GLF_INVALIDATE_IN_PROGRESS	= 8,

	GLF_HAVE_REPLY			= 9,

	GLF_INITIAL			= 10,

	GLF_HAVE_FROZEN_REPLY		= 11,

fs/gfs2/trace_gfs2.h

+0 −1
Original line number Diff line number Diff line
@@ -52,7 +52,6 @@ 
	{(1UL << GLF_DEMOTE_IN_PROGRESS),	"p" },		\

	{(1UL << GLF_DIRTY),			"y" },		\

	{(1UL << GLF_LFLUSH),			"f" },		\

	{(1UL << GLF_INVALIDATE_IN_PROGRESS),	"i" },		\

	{(1UL << GLF_PENDING_REPLY),		"R" },		\

	{(1UL << GLF_HAVE_REPLY),		"r" },		\

	{(1UL << GLF_INITIAL),			"a" },		\