From: Trond Myklebust <trond.myklebust@hammerspace.com>
Date: Wed, 1 Apr 2020 10:07:16 -0400
Subject: [PATCH] NFS: Fix a page leak in nfs_destroy_unlinked_subrequests()
Git-commit: add42de31721fa29ed77a7ce388674d69f9d31a4
Patch-mainline: v5.7-rc1
References: git-fixes

When we detach a subrequest from the list, we must also release the
reference it holds to the parent.

Fixes: 5b2b5187fa85 ("NFS: Fix nfs_page_group_destroy() and nfs_lock_and_join_requests() race cases")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Acked-by: NeilBrown <neilb@suse.com>

---
 fs/nfs/write.c |    1 +
 1 file changed, 1 insertion(+)

--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -444,6 +444,7 @@ nfs_destroy_unlinked_subrequests(struct
 		}
 
 		subreq->wb_head = subreq;
+		nfs_release_request(old_head);
 
 		if (test_and_clear_bit(PG_INODE_REF, &subreq->wb_flags)) {
 			nfs_release_request(subreq);