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Subject: [PATCH 4/8] NFSD: only call fh_unlock() once in nfsd_link()
From:   NeilBrown <neilb@suse.de>
To:     Chuck Lever <chuck.lever@oracle.com>,
        Jeff Layton <jlayton@kernel.org>
Cc:     linux-nfs@vger.kernel.org
Date:   Wed, 06 Jul 2022 14:18:12 +1000
Message-ID: <165708109258.1940.6581517569232462503.stgit@noble.brown>
In-Reply-To: <165708033167.1940.3364591321728458949.stgit@noble.brown>
References: <165708033167.1940.3364591321728458949.stgit@noble.brown>
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On non-error paths, nfsd_link() calls fh_unlock() twice.  This is safe
because fh_unlock() records that the unlock has been done and doesn't
repeat it.
However it makes the code a little confusing and interferes with changes
that are planned for directory locking.

So rearrange the code to ensure fh_unlock() is called exactly once if
fh_lock() was called.

Signed-off-by: NeilBrown <neilb@suse.de>
---
 fs/nfsd/vfs.c |   18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 3f4579f5775c..4916c29af0fa 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1551,8 +1551,10 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
 
 	dnew = lookup_one_len(name, ddir, len);
 	host_err = PTR_ERR(dnew);
-	if (IS_ERR(dnew))
-		goto out_nfserr;
+	if (IS_ERR(dnew)) {
+		err = nfserrno(host_err);
+		goto out_unlock;
+	}
 
 	dold = tfhp->fh_dentry;
 
@@ -1571,17 +1573,17 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
 		else
 			err = nfserrno(host_err);
 	}
-out_dput:
 	dput(dnew);
-out_unlock:
-	fh_unlock(ffhp);
+out_drop_write:
 	fh_drop_write(tfhp);
 out:
 	return err;
 
-out_nfserr:
-	err = nfserrno(host_err);
-	goto out_unlock;
+out_dput:
+	dput(dnew);
+out_unlock:
+	fh_unlock(ffhp);
+	goto out_drop_write;
 }
 
 static void