[Cluster-devel] [PATCH AUTOSEL 5.14 111/252] gfs2: Fix glock recursion in freeze_go_xmote_bh

[Cluster-devel] [PATCH AUTOSEL 5.14 111/252] gfs2: Fix glock recursion in freeze_go_xmote_bh

[Sasha Levin]

From: Bob Peterson <rpeterso@redhat.com>

[ Upstream commit 9d9b16054b7d357afde69a027514c695092b0d22 ]

We must not call gfs2_consist (which does a file system withdraw) from
the freeze glock's freeze_go_xmote_bh function because the withdraw
will try to use the freeze glock, thus causing a glock recursion error.

This patch changes freeze_go_xmote_bh to call function
gfs2_assert_withdraw_delayed instead of gfs2_consist to avoid recursion.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/gfs2/glops.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
index 54d3fbeb3002..384565d63eea 100644
--- a/fs/gfs2/glops.c
+++ b/fs/gfs2/glops.c
@@ -610,16 +610,13 @@ static int freeze_go_xmote_bh(struct gfs2_glock *gl)
 		j_gl->gl_ops->go_inval(j_gl, DIO_METADATA);
 
 		error = gfs2_find_jhead(sdp->sd_jdesc, &head, false);
-		if (error)
-			gfs2_consist(sdp);
-		if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT))
-			gfs2_consist(sdp);
-
-		/*  Initialize some head of the log stuff  */
-		if (!gfs2_withdrawn(sdp)) {
-			sdp->sd_log_sequence = head.lh_sequence + 1;
-			gfs2_log_pointers_init(sdp, head.lh_blkno);
-		}
+		if (gfs2_assert_withdraw_delayed(sdp, !error))
+			return error;
+		if (gfs2_assert_withdraw_delayed(sdp, head.lh_flags &
+						 GFS2_LOG_HEAD_UNMOUNT))
+			return -EIO;
+		sdp->sd_log_sequence = head.lh_sequence + 1;
+		gfs2_log_pointers_init(sdp, head.lh_blkno);
 	}
 	return 0;
 }
-- 
2.30.2

[Cluster-devel] [PATCH AUTOSEL 5.14 180/252] gfs2: Don't call dlm after protocol is unmounted

[Sasha Levin]

From: Bob Peterson <rpeterso@redhat.com>

[ Upstream commit d1340f80f0b8066321b499a376780da00560e857 ]

In the gfs2 withdraw sequence, the dlm protocol is unmounted with a call
to lm_unmount. After a withdraw, users are allowed to unmount the
withdrawn file system. But at that point we may still have glocks left
over that we need to free via unmount's call to gfs2_gl_hash_clear.
These glocks may have never been completed because of whatever problem
caused the withdraw (IO errors or whatever).

Before this patch, function gdlm_put_lock would still try to call into
dlm to unlock these leftover glocks, which resulted in dlm returning
-EINVAL because the lock space was abandoned. These glocks were never
freed because there was no mechanism after that to free them.

This patch adds a check to gdlm_put_lock to see if the locking protocol
was inactive (DFL_UNMOUNT flag) and if so, free the glock and not
make the invalid call into dlm.

I could have combined this "if" with the one that follows, related to
leftover glock LVBs, but I felt the code was more readable with its own
if clause.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/gfs2/lock_dlm.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/fs/gfs2/lock_dlm.c b/fs/gfs2/lock_dlm.c
index dac040162ecc..50578f881e6d 100644
--- a/fs/gfs2/lock_dlm.c
+++ b/fs/gfs2/lock_dlm.c
@@ -299,6 +299,11 @@ static void gdlm_put_lock(struct gfs2_glock *gl)
 	gfs2_sbstats_inc(gl, GFS2_LKS_DCOUNT);
 	gfs2_update_request_times(gl);
 
+	/* don't want to call dlm if we've unmounted the lock protocol */
+	if (test_bit(DFL_UNMOUNT, &ls->ls_recover_flags)) {
+		gfs2_glock_free(gl);
+		return;
+	}
 	/* don't want to skip dlm_unlock writing the lvb when lock has one */
 
 	if (test_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags) &&
-- 
2.30.2