[Cluster-devel] [GFS2] Move "first lock" glops call

[Steven Whitehouse <swhiteho@redhat.com>]

Hi,

Further patches in the glock cleanup series,

Steve.

From 109c714b2b66e656b0004a628239cdf571eafe46 Mon Sep 17 00:00:00 2001
From: Steven Whitehouse <swhiteho@redhat.com>
Date: Tue, 31 Jul 2007 16:53:31 +0100
Subject: [PATCH] [GFS2] Move "first lock" glops call

Rather than setting a flag "HIF_FIRST" for each granted lock holder
that is the first one on the glock's list, and then call the ->go_lock()
glops function later, in the context of the process waiting for the glock,
this patch calls the ->go_lock() function directly, removing the need
for the HIF_FIRST flag.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index d564876..fd8cf02 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -467,6 +467,20 @@ static void rq_mutex(struct gfs2_glock *gl)
 	wake_up_bit(&gh->gh_iflags, HIF_WAIT);
 }
 
+static void first_holder(struct gfs2_holder *gh)
+{
+	struct gfs2_glock *gl = gh->gh_gl;
+	const struct gfs2_glock_operations *glops = gl->gl_ops;
+
+	if (glops->go_lock) {
+		spin_unlock(&gl->gl_spin);
+		gh->gh_error = glops->go_lock(gh);
+		spin_lock(&gl->gl_spin);
+		if (gh->gh_error)
+			list_del_init(&gh->gh_list);
+	}
+}
+
 /**
  * rq_promote - process a promote request in the queue
  * @gh: the glock holder
@@ -493,8 +507,7 @@ static int rq_promote(struct gfs2_glock *gl)
 	}
 
 	if (list_empty(&gl->gl_holders)) {
-		set_bit(HIF_FIRST, &gh->gh_iflags);
-		set_bit(GLF_LOCK, &gl->gl_flags);
+		first_holder(gh);
 	} else {
 		struct gfs2_holder *next_gh;
 		if (gh->gh_state == LM_ST_EXCLUSIVE)
@@ -748,10 +761,9 @@ static void xmote_bh(struct gfs2_glock *gl, unsigned int ret)
 			goto out;
 		if (relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) {
 			list_add_tail(&gh->gh_list, &gl->gl_holders);
-			gh->gh_error = 0;
 			set_bit(HIF_HOLDER, &gh->gh_iflags);
-			set_bit(HIF_FIRST, &gh->gh_iflags);
-			op_done = 0;
+			gh->gh_error = 0;
+			first_holder(gh);
 			goto out;
 		}
 		gh->gh_error = GLR_TRYFAILED;
@@ -868,7 +880,6 @@ static int glock_wait_internal(struct gfs2_holder *gh)
 {
 	struct gfs2_glock *gl = gh->gh_gl;
 	struct gfs2_sbd *sdp = gl->gl_sbd;
-	const struct gfs2_glock_operations *glops = gl->gl_ops;
 
 	if (test_bit(HIF_ABORTED, &gh->gh_iflags))
 		return -EIO;
@@ -898,25 +909,6 @@ static int glock_wait_internal(struct gfs2_holder *gh)
 	gfs2_assert_withdraw(sdp, relaxed_state_ok(gl->gl_state, gh->gh_state,
 						   gh->gh_flags));
 
-	if (test_bit(HIF_FIRST, &gh->gh_iflags)) {
-		gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
-
-		if (glops->go_lock) {
-			gh->gh_error = glops->go_lock(gh);
-			if (gh->gh_error) {
-				spin_lock(&gl->gl_spin);
-				list_del_init(&gh->gh_list);
-				spin_unlock(&gl->gl_spin);
-			}
-		}
-
-		spin_lock(&gl->gl_spin);
-		gl->gl_req_gh = NULL;
-		clear_bit(GLF_LOCK, &gl->gl_flags);
-		run_queue(gl);
-		spin_unlock(&gl->gl_spin);
-	}
-
 	return gh->gh_error;
 }
 
diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index cda2fba..1d90ff1 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -135,7 +135,6 @@ enum {
 
 	/* States */
 	HIF_HOLDER		= 6,
-	HIF_FIRST		= 7,
 	HIF_ABORTED		= 9,
 	HIF_WAIT		= 10,
 };
-- 
1.5.1.2