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Subject: [PATCH v4 2/7] NFSD: Revert "NFSD: NFSv4 CLOSE should release an
 nfsd_file immediately"
From:   Chuck Lever <chuck.lever@oracle.com>
To:     linux-nfs@vger.kernel.org
Cc:     neilb@suse.de
Date:   Tue, 18 Oct 2022 15:58:32 -0400
Message-ID: <166612311196.1291.3976661000746956975.stgit@manet.1015granger.net>
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This reverts commit 5e138c4a750dc140d881dab4a8804b094bbc08d2.

That commit attempted to make files available to other users as soon
as all NFSv4 clients were done with them, rather than waiting until
the filecache LRU had garbage collected them.

It gets the reference counting wrong, for one thing.

But it also misses that DELEGRETURN should release a file in the
same fashion. In fact, any nfsd_file_put() on an file held open
by an NFSv4 client needs potentially to release the file
immediately...

Clear the way for implementing that idea.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 fs/nfsd/filecache.c |   18 ------------------
 fs/nfsd/filecache.h |    1 -
 fs/nfsd/nfs4state.c |    4 ++--
 3 files changed, 2 insertions(+), 21 deletions(-)

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index a2adfc247648..b7aa523c2010 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -444,24 +444,6 @@ nfsd_file_put(struct nfsd_file *nf)
 		nfsd_file_put_noref(nf);
 }
 
-/**
- * nfsd_file_close - Close an nfsd_file
- * @nf: nfsd_file to close
- *
- * If this is the final reference for @nf, free it immediately.
- * This reflects an on-the-wire CLOSE or DELEGRETURN into the
- * VFS and exported filesystem.
- */
-void nfsd_file_close(struct nfsd_file *nf)
-{
-	nfsd_file_put(nf);
-	if (refcount_dec_if_one(&nf->nf_ref)) {
-		nfsd_file_unhash(nf);
-		nfsd_file_lru_remove(nf);
-		nfsd_file_free(nf);
-	}
-}
-
 struct nfsd_file *
 nfsd_file_get(struct nfsd_file *nf)
 {
diff --git a/fs/nfsd/filecache.h b/fs/nfsd/filecache.h
index 8e8c0c47d67d..f81c198f4ed6 100644
--- a/fs/nfsd/filecache.h
+++ b/fs/nfsd/filecache.h
@@ -52,7 +52,6 @@ void nfsd_file_cache_shutdown(void);
 int nfsd_file_cache_start_net(struct net *net);
 void nfsd_file_cache_shutdown_net(struct net *net);
 void nfsd_file_put(struct nfsd_file *nf);
-void nfsd_file_close(struct nfsd_file *nf);
 struct nfsd_file *nfsd_file_get(struct nfsd_file *nf);
 void nfsd_file_close_inode_sync(struct inode *inode);
 bool nfsd_file_is_cached(struct inode *inode);
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index c5d199d7e6b4..2b850de288cf 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -820,9 +820,9 @@ static void __nfs4_file_put_access(struct nfs4_file *fp, int oflag)
 			swap(f2, fp->fi_fds[O_RDWR]);
 		spin_unlock(&fp->fi_lock);
 		if (f1)
-			nfsd_file_close(f1);
+			nfsd_file_put(f1);
 		if (f2)
-			nfsd_file_close(f2);
+			nfsd_file_put(f2);
 	}
 }