From mboxrd@z Thu Jan 1 00:00:00 1970 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 6DEA03BC662 for ; Thu, 23 Apr 2026 22:22:41 +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=1776982964; cv=none; b=NWMyxuE6NtG223XqK6KJnAOSCQIydUfAeTwWYaq1rayFc2mAED9VgsPigsd7q0kmA1UTNS16ejXGv639svx09whMn0im+ZOTF/rPAXg5ieevkRbV84VVKQccYxrOIVAQ29L6Y8PPUh1+232GkCB3KURPsD6GyV875t+MisQyJKM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776982964; c=relaxed/simple; bh=3aYouAujFzp76xqqlG9o4vknZZvSlVMk3kOrrxli+y8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tp2dx7qteJmKMKzYRTqMq9tmHzXvGunt4dWFw+6f2L4OdwiZQ7UFOYXTcuUEYSa+CJebw9EVcra1aJ1nMZqqv/lHABVP96gPz6j3nr/D4qk2xCvyycGAsiqRIcI3LoYy0qWJZDoaND6M4VUBMsrdBxveWHqVlBI1QYycG9khCas= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine 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=MgOi9OZq; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine 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="MgOi9OZq" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1776982960; 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: in-reply-to:in-reply-to:references:references; bh=CEaZFT1kA2C9fmI8tLKUXOafS9Zq2QwNR5SdFuG0lEc=; b=MgOi9OZqYzSk/Lhfh/aXbxwDXT/KRvaphGEMyzrO8WMBgBkg9ErPWKJOyK0oCsu/f9AASy UR7kD6e0wRsPpcWFIkmSkl5jtRrKYsEUQpFl2JqbiObokjET4O0r/DmmE9g0lEPiek939I quRgxnzTIOXDC1d80LXWl5Hkn7T+CP8= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-20-6mRXVomyPvGKAhZHmx0xIA-1; Thu, 23 Apr 2026 18:22:37 -0400 X-MC-Unique: 6mRXVomyPvGKAhZHmx0xIA-1 X-Mimecast-MFC-AGG-ID: 6mRXVomyPvGKAhZHmx0xIA_1776982956 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (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 mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id BC47C1956095; Thu, 23 Apr 2026 22:22:35 +0000 (UTC) Received: from warthog.procyon.org.com (unknown [10.44.48.17]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 2CCFF19560AB; Thu, 23 Apr 2026 22:22:31 +0000 (UTC) From: David Howells To: Christian Brauner Cc: David Howells , Paulo Alcantara , netfs@lists.linux.dev, linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org, ceph-devel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Marc Dionne Subject: [PATCH 3/4] afs: Fix afs_get_link() to take validate_lock around afs_read_single() Date: Thu, 23 Apr 2026 23:22:06 +0100 Message-ID: <20260423222209.3054909-4-dhowells@redhat.com> In-Reply-To: <20260423222209.3054909-1-dhowells@redhat.com> References: <20260423222209.3054909-1-dhowells@redhat.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Fix afs_get_link() to take the validate_lock around afs_read_single() to prevent races between multiple ->get_link() calls. Fixes: eae9e78951bb ("afs: Use netfslib for symlinks, allowing them to be cached") Closes: https://sashiko.dev/#/patchset/20260326104544.509518-1-dhowells%40redhat.com Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org --- fs/afs/inode.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/fs/afs/inode.c b/fs/afs/inode.c index 06e25e1b12df..5207c4a003f6 100644 --- a/fs/afs/inode.c +++ b/fs/afs/inode.c @@ -78,10 +78,19 @@ const char *afs_get_link(struct dentry *dentry, struct inode *inode, goto good; fetch: - ret = afs_read_single(vnode, NULL); - if (ret < 0) - return ERR_PTR(ret); - set_bit(AFS_VNODE_DIR_READ, &vnode->flags); + if (down_write_killable(&vnode->validate_lock) < 0) + return ERR_PTR(-ERESTARTSYS); + if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags) || + !test_bit(AFS_VNODE_DIR_READ, &vnode->flags)) { + ret = afs_read_single(vnode, NULL); + if (ret < 0) { + up_write(&vnode->validate_lock); + return ERR_PTR(ret); + } + set_bit(AFS_VNODE_DIR_READ, &vnode->flags); + } + + up_write(&vnode->validate_lock); good: folio = folioq_folio(vnode->directory, 0);