FAILED: patch "[PATCH] gfs2: Put bitmap buffers in put_super" failed to apply to 4.4-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From 10283ea525d30f2e99828978fd04d8427876a7ad Mon Sep 17 00:00:00 2001
From: Andreas Gruenbacher <agruenba@redhat.com>
Date: Mon, 5 Nov 2018 22:57:24 +0000
Subject: [PATCH] gfs2: Put bitmap buffers in put_super

gfs2_put_super calls gfs2_clear_rgrpd to destroy the gfs2_rgrpd objects
attached to the resource group glocks.  That function should release the
buffers attached to the gfs2_bitmap objects (bi_bh), but the call to
gfs2_rgrp_brelse for doing that is missing.

When gfs2_releasepage later runs across these buffers which are still
referenced, it refuses to free them.  This causes the pages the buffers
are attached to to remain referenced as well.  With enough mount/unmount
cycles, the system will eventually run out of memory.

Fix this by adding the missing call to gfs2_rgrp_brelse in
gfs2_clear_rgrpd.

(Also fix a gfs2_rgrp_relse -> gfs2_rgrp_brelse typo in a comment.)

Fixes: 39b0f1e92908 ("GFS2: Don't brelse rgrp buffer_heads every allocation")
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index ffe3032b1043..b08a530433ad 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -733,6 +733,7 @@ void gfs2_clear_rgrpd(struct gfs2_sbd *sdp)
 
 		if (gl) {
 			glock_clear_object(gl, rgd);
+			gfs2_rgrp_brelse(rgd);
 			gfs2_glock_put(gl);
 		}
 
@@ -1174,7 +1175,7 @@ static u32 count_unlinked(struct gfs2_rgrpd *rgd)
  * @rgd: the struct gfs2_rgrpd describing the RG to read in
  *
  * Read in all of a Resource Group's header and bitmap blocks.
- * Caller must eventually call gfs2_rgrp_relse() to free the bitmaps.
+ * Caller must eventually call gfs2_rgrp_brelse() to free the bitmaps.
  *
  * Returns: errno
  */