Patch "NFSD: NFSv4 CLOSE should release an nfsd_file immediately" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    NFSD: NFSv4 CLOSE should release an nfsd_file immediately

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     nfsd-nfsv4-close-should-release-an-nfsd_file-immedia.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 149b9530aff41b6f59d1bce85950a093309f315c
Author: Chuck Lever <chuck.lever@xxxxxxxxxx>
Date:   Fri Jul 8 14:27:02 2022 -0400

    NFSD: NFSv4 CLOSE should release an nfsd_file immediately
    
    [ Upstream commit 5e138c4a750dc140d881dab4a8804b094bbc08d2 ]
    
    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@xxxxxxxxxxxx>
    Link: https://bugzilla.linux-nfs.org/show_bug.cgi?387
    Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
    Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index 26cfae138b906..7ad27655db699 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -451,6 +451,24 @@ 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 ee9ed99d8b8fa..28145f1628923 100644
--- a/fs/nfsd/filecache.h
+++ b/fs/nfsd/filecache.h
@@ -52,6 +52,7 @@ 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 d349abf0821d6..923eec2716d75 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -831,9 +831,9 @@ 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);
 	}
 }