From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B48F118FC67; Sun, 23 Jun 2024 13:44:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719150295; cv=none; b=DE277uP1i8sHJF9KfbDyJuq2y63yOQWCfs4a7QasvbUWHJ/G1tQgYNopXi7FoVDWf7qeZp6hFnaB+U+wB41nuPRAtIeKGkE2AeOyRJ1b1awYknnrvy6b+EdYhODoRh6SsGwCGMZumqTjJdKsyHYAXBorQMdW/ON7Y5j8h3/v2K0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719150295; c=relaxed/simple; bh=MnYMWHg3/JEvruJ0mhVXxGxohEky6H1ESRnZVFWtXtU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pXi0ZpXrO5Au4zbDyKCBt4uUfPsPSN7aKUHUjdouMLHnPtqrg0v7OKqDliZ8wBRRRYqW7zZOXoW1csjSZCMFERpqXA4MgvU5b7AyVjXunILO4rgnA/zF5V3bGm49YxbFGuEKRPPJ6vD65RCqKKiKBseYLJFD2eH4x/hjJT1gQ/s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lYvy9Y3c; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="lYvy9Y3c" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AD593C2BD10; Sun, 23 Jun 2024 13:44:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719150295; bh=MnYMWHg3/JEvruJ0mhVXxGxohEky6H1ESRnZVFWtXtU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lYvy9Y3cXsP+qdlxxL6CchAiQjNWJwg+r+zBFCgVxmNgefHImxSdrxKjb/vmqwUnf QAm6HBPinIoBAegntJFNfD3lalp2EdAuHhRceLFOJamJ+l1OwMmUcDd8pKOp6NrxeC lteKHHTzrQ3ZJ+Vx8ylam+4alwixeX+zOtrG8mjQIHGqLpVovag9QYQ5fzkrXjMSqQ rI8Bh8q4wWDMJK7DPrWxBUr1ftbLMBSOf0zmbsQOJ4/6fW+17evRluaTSqGREWbhby PZOqFBYX02bZ4gCyttouXUlxOThXVb1m7/3XQzU/dOrhWu/LTuWmXNVMAJ6TcPkBF9 p0xNIeJpMifZw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Scott Mayhew , Trond Myklebust , Sasha Levin , trondmy@kernel.org, anna@kernel.org, linux-nfs@vger.kernel.org Subject: [PATCH AUTOSEL 6.6 04/16] nfs: don't invalidate dentries on transient errors Date: Sun, 23 Jun 2024 09:44:33 -0400 Message-ID: <20240623134448.809470-4-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240623134448.809470-1-sashal@kernel.org> References: <20240623134448.809470-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.6.35 Content-Transfer-Encoding: 8bit From: Scott Mayhew [ Upstream commit 0c8c7c559740d2d8b66048162af6c4dba8f0c88c ] 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 Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- fs/nfs/dir.c | 27 +++++++++++++-------------- 1 file changed, 13 insertions(+), 14 deletions(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 2a0f069d5a096..39f7549afcf5b 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -1625,7 +1625,16 @@ nfs_lookup_revalidate_done(struct inode *dir, struct dentry *dentry, switch (error) { case 1: break; - case 0: + case -ETIMEDOUT: + if (inode && (IS_ROOT(dentry) || + NFS_SERVER(inode)->flags & NFS_MOUNT_SOFTREVAL)) + error = 1; + break; + case -ESTALE: + case -ENOENT: + error = 0; + fallthrough; + default: /* * We can't d_drop the root of a disconnected tree: * its d_hash is on the s_anon list and d_drop() would hide @@ -1680,18 +1689,8 @@ 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 +1734,7 @@ 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 +1779,7 @@ 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 -- 2.43.0