[PATCH 4/4] nfsd: add some comments to nfsd_file_do_acquire
From: Jeff Layton <jlayton@kernel.org>
Date: 2023-01-05 12:15:48
Subsystem:
filesystems (vfs and infrastructure), kernel nfsd, sunrpc, and lockd servers, the rest · Maintainers:
Alexander Viro, Christian Brauner, Chuck Lever, Jeff Layton, Linus Torvalds
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