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From:   Jeff Layton <jlayton@kernel.org>
To:     chuck.lever@oracle.com
Cc:     linux-nfs@vger.kernel.org, David Howells <dhowells@redhat.com>
Subject: [PATCH 4/4] nfsd: add some comments to nfsd_file_do_acquire
Date:   Thu,  5 Jan 2023 07:15:12 -0500
Message-Id: <20230105121512.21484-5-jlayton@kernel.org>
In-Reply-To: <20230105121512.21484-1-jlayton@kernel.org>
References: <20230105121512.21484-1-jlayton@kernel.org>
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David Howells mentioned that he found this bit of code confusing, so
sprinkle in some comments to clarify.

Reported-by: David Howells <dhowells@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 fs/nfsd/filecache.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index f0ca9501edb2..5724baad09ec 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -1105,6 +1105,11 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	rcu_read_unlock();
 
 	if (nf) {
+		/*
+		 * If the nf is on the LRU then it holds an extra reference
+		 * that must be put if it's removed. It had better not be
+		 * the last one however, since we should hold another.
+		 */
 		if (nfsd_file_lru_remove(nf))
 			WARN_ON_ONCE(refcount_dec_and_test(&nf->nf_ref));
 		goto wait_for_construction;
-- 
2.39.0