From: Andreas Gruenbacher <agruenba@redhat.com>
Date: Mon, 22 Nov 2021 16:32:35 +0000 (+0100)
Subject: gfs2: Fix remote demote of weak glock holders
X-Git-Tag: baikal/aarch64/sdk6.1~5163^2~3
X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=ca74a42356e728fd47a634c12876724621886d9e;p=kernel.git

gfs2: Fix remote demote of weak glock holders

When we mock up a temporary holder in gfs2_glock_cb to demote weak holders in
response to a remote locking conflict, we don't set the HIF_HOLDER flag.  This
causes function may_grant to BUG.  Fix by setting the missing HIF_HOLDER flag
in the mock glock holder.

In addition, define the mock glock holder where it is used.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 8dbd6fe664204..44a7a4288956b 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -1857,7 +1857,6 @@ void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs)
 
 void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state)
 {
-	struct gfs2_holder mock_gh = { .gh_gl = gl, .gh_state = state, };
 	unsigned long delay = 0;
 	unsigned long holdtime;
 	unsigned long now = jiffies;
@@ -1890,8 +1889,13 @@ void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state)
 	 * keep the glock until the last strong holder is done with it.
 	 */
 	if (!find_first_strong_holder(gl)) {
-		if (state == LM_ST_UNLOCKED)
-			mock_gh.gh_state = LM_ST_EXCLUSIVE;
+		struct gfs2_holder mock_gh = {
+			.gh_gl = gl,
+			.gh_state = (state == LM_ST_UNLOCKED) ?
+				    LM_ST_EXCLUSIVE : state,
+			.gh_iflags = BIT(HIF_HOLDER)
+		};
+
 		demote_incompat_holders(gl, &mock_gh);
 	}
 	handle_callback(gl, state, delay, true);