[PATCH 6.1 010/451] nfsd: add some comments to nfsd_file_do_acquire

Sasha Levin
2024-03-24T23:12:19Z

From: Jeff Layton <jlayton@kernel.org>

[ Upstream commit b680cb9b737331aad271feebbedafb865504e234 ]

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>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@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 ab37b85b72077..50349449a4e52 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -1094,6 +1094,11 @@ 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;
--
2.43.0