netdev - [PATCH v2 31/31] NFSD: NFSv4 CLOSE should release an nfsd

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <165643974865.84360.14514065655454215617.stgit@manet.1015granger.net>
Date:   Tue, 28 Jun 2022 14:09:08 -0400
From:   Chuck Lever <chuck.lever@...cle.com>
To:     linux-nfs@...r.kernel.org, netdev@...r.kernel.org
Cc:     david@...morbit.com, jlayton@...hat.com, tgraf@...g.ch
Subject: [PATCH v2 31/31] NFSD: NFSv4 CLOSE should release an nfsd_file
 immediately

The last close of a file should enable other accessors to open and
use that file immediately. Leaving the file open in the filecache
prevents other users from accessing that file until the filecache
garbage-collects the file -- sometimes that takes several seconds.

Reported-by: Wang Yugui <wangyugui@...-tech.com>
Link: https://bugzilla.linux-nfs.org/show_bug.cgi?387
Signed-off-by: Chuck Lever <chuck.lever@...cle.com>
---
 fs/nfsd/filecache.c |   18 ++++++++++++++++++
 fs/nfsd/filecache.h |    1 +
 fs/nfsd/nfs4state.c |    4 ++--
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index cee2770e13e5..5c2a68489480 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -458,6 +458,24 @@ 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 5ce3fdf3b729..c1f28a0e9c0f 100644
--- a/fs/nfsd/filecache.h
+++ b/fs/nfsd/filecache.h
@@ -54,6 +54,7 @@ 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 3a05c095dfe5..9d1a3e131c49 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_put(f1);
+			nfsd_file_close(f1);
 		if (f2)
-			nfsd_file_put(f2);
+			nfsd_file_close(f2);
 	}
 }