From patchwork Wed May 22 22:19:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Scott Mayhew X-Patchwork-Id: 13671143 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DC19F7EF0C for ; Wed, 22 May 2024 22:19:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716416361; cv=none; b=hsYs2DreojYJCMAozq5OFQJYEeLRvdiufplvAIYCWAfkxalPvftI1774RhAPj5HBRhtPPeocU0mnXmLUrzXVCSVUVKfH2KRlMMg0MipTcFQnezVrF2rJbIicIxg9s0S3JeAU+GD8eMgio2FieFJt31iqIjRvV3bPqWyG17AtaUY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716416361; c=relaxed/simple; bh=bPrfsJgJCoSDDmHu6YtGdm8J4XVulVyUzcd02lnrDvc=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=m8m9MuQNINl/qGCDiP96FDWP7D7c5anxLqnAI7qYENN4kXfcCHEqZF3iwqztj0a8GXDWz94uAtl49ZAg7CyqB1e7/eykQYHDkGC8e6DusaoUpmgru2VNb2VDFzuQlLXj7SLhjqilHvLID/Q4NZHmqOpWNiomd626T3Iy8NqlagM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=VTVRsmX9; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="VTVRsmX9" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1716416358; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=k5zpPnXo01Dv9bzCOALzQrACjBZMOCaDc18rYhkXfD0=; b=VTVRsmX919infP1QdUlzGOlsgr83m/g9Nl+QtaX7VD2yDSkQyoPiB4fprhFGG7uvyQpC5m L69JtWsLhdCKHfl51Ufs3rSUzNaA7HAo9UDGXzQ/Ba7VwUGcN7O+vgRdnDLTj2Bgyd+8OP x/cKOmyAThyZW3AEm6U3kMXeF/VCDj0= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-62-xLAL9ZBCMh6hEh55HtiQow-1; Wed, 22 May 2024 18:19:17 -0400 X-MC-Unique: xLAL9ZBCMh6hEh55HtiQow-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id C9541800042; Wed, 22 May 2024 22:19:16 +0000 (UTC) Received: from aion.redhat.com (unknown [10.22.33.56]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AA4E7100046D; Wed, 22 May 2024 22:19:16 +0000 (UTC) Received: from aion.redhat.com (localhost [IPv6:::1]) by aion.redhat.com (Postfix) with ESMTP id 147BE14C3A7; Wed, 22 May 2024 18:19:16 -0400 (EDT) From: Scott Mayhew To: trond.myklebust@hammerspace.com, anna.schumaker@netapp.com Cc: neilb@suse.de, linux-nfs@vger.kernel.org Subject: [PATCH] nfs: don't invalidate dentries on transient errors Date: Wed, 22 May 2024 18:19:16 -0400 Message-ID: <20240522221916.447239-1-smayhew@redhat.com> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 This is a slight variation on a patch previously proposed by Neil Brown that never got merged. Prior to commit 5ceb9d7fdaaf ("NFS: Refactor nfs_lookup_revalidate()"), any error from nfs_lookup_verify_inode() other than -ESTALE would result in nfs_lookup_revalidate() returning that error (-ESTALE is mapped to zero). Since that commit, all errors result in nfs_lookup_revalidate() returning zero, resulting in dentries being invalidated where they previously were not (particularly in the case of -ERESTARTSYS). Fix it by passing the actual error code to nfs_lookup_revalidate_done(), and leaving the decision on whether to map the error code to zero or one to nfs_lookup_revalidate_done(). A simple reproducer is to run the following python code in a subdirectory of an NFS mount (not in the root of the NFS mount): ---8<--- import os import multiprocessing import time if __name__=="__main__": multiprocessing.set_start_method("spawn") count = 0 while True: try: os.getcwd() pool = multiprocessing.Pool(10) pool.close() pool.terminate() count += 1 except Exception as e: print(f"Failed after {count} iterations") print(e) break ---8<--- Prior to commit 5ceb9d7fdaaf, the above code would run indefinitely. After commit 5ceb9d7fdaaf, it fails almost immediately with -ENOENT. Signed-off-by: Scott Mayhew --- fs/nfs/dir.c | 24 +++++++++++------------- 1 file changed, 11 insertions(+), 13 deletions(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index ac505671efbd..d9264ed4ac52 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -1635,6 +1635,14 @@ nfs_lookup_revalidate_done(struct inode *dir, struct dentry *dentry, if (inode && IS_ROOT(dentry)) error = 1; break; + case -ESTALE: + case -ENOENT: + error = 0; + break; + case -ETIMEDOUT: + if (NFS_SERVER(inode)->flags & NFS_MOUNT_SOFTREVAL) + error = 1; + break; } trace_nfs_lookup_revalidate_exit(dir, dentry, 0, error); return error; @@ -1680,18 +1688,8 @@ static int nfs_lookup_revalidate_dentry(struct inode *dir, dir_verifier = nfs_save_change_attribute(dir); ret = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr); - if (ret < 0) { - switch (ret) { - case -ESTALE: - case -ENOENT: - ret = 0; - break; - case -ETIMEDOUT: - if (NFS_SERVER(inode)->flags & NFS_MOUNT_SOFTREVAL) - ret = 1; - } + if (ret < 0) goto out; - } /* Request help from readdirplus */ nfs_lookup_advise_force_readdirplus(dir, flags); @@ -1735,7 +1733,7 @@ nfs_do_lookup_revalidate(struct inode *dir, struct dentry *dentry, unsigned int flags) { struct inode *inode; - int error; + int error = 0; nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE); inode = d_inode(dentry); @@ -1780,7 +1778,7 @@ nfs_do_lookup_revalidate(struct inode *dir, struct dentry *dentry, out_bad: if (flags & LOOKUP_RCU) return -ECHILD; - return nfs_lookup_revalidate_done(dir, dentry, inode, 0); + return nfs_lookup_revalidate_done(dir, dentry, inode, error); } static int