From patchwork Fri Nov 8 17:32:04 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13868733 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 124A721F4D1 for ; Fri, 8 Nov 2024 17:33:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731087197; cv=none; b=HcnIjcU+Rz07sYgg3n079a6L2dtE96xprbqH+cRqyKSa5Iw8hof881Mc4pjdpKwrKvdZcS51DAlM3dZrYxVaFLcg0qV91crpF9DHJF0/LMWl4Mvdt8BMFGQm8vGABKV0OVo/5aaqtfLoCv2udu8glqDkE3ahF6JsNFCWnZGx5tg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731087197; c=relaxed/simple; bh=IB2Hra3PbQqimrEPUTwV6xl6xpFuitl8Oqr5TkFFgbI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BqbyEbPsPYYmofACldUBXCdiuGM2nRft6JTnBXAzDY1zvju64GUlPdr+Oo64nQYArGS2f3ylGwGbquhxaWQ252ZvedcxsoaSaIkqmjYXYMii40EVqHVtWLjzbysY1m0NhhbUC4GZc82qmm9NbE/jqw+P75hPXEYLAPvK40vblOo= 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=MZW0MyjA; arc=none smtp.client-ip=170.10.129.124 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="MZW0MyjA" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1731087194; 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=TRktXy0njOtGduc146rNPLaeznRZ8wjmjmNrqe7WMw8=; b=MZW0MyjAOBaH+dKX85Qhe+Vx5NlqkshlAhUnWr1SK3r35ekdtj3uUcs58tMPEUO8HhL+sc +nS1Jv9Yc3P42WnmnMMMbSvsyuwNE1eUmjfknBob1O8h7BVWg9YO7nZXoRnzKeynjrTMaT tLDSRZBfh5eB3xZHTeTj4NvRIywNesY= Received: from mx-prod-mc-02.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-43-uCukTaVKP9aVL2dtzxjKJg-1; Fri, 08 Nov 2024 12:33:11 -0500 X-MC-Unique: uCukTaVKP9aVL2dtzxjKJg-1 X-Mimecast-MFC-AGG-ID: uCukTaVKP9aVL2dtzxjKJg Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (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-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4876819540F1; Fri, 8 Nov 2024 17:33:08 +0000 (UTC) Received: from warthog.procyon.org.uk.com (unknown [10.42.28.231]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 7704E300019E; Fri, 8 Nov 2024 17:33:02 +0000 (UTC) From: David Howells To: Christian Brauner , Steve French , Matthew Wilcox Cc: David Howells , Jeff Layton , Gao Xiang , Dominique Martinet , Marc Dionne , Paulo Alcantara , Shyam Prasad N , Tom Talpey , Eric Van Hensbergen , Ilya Dryomov , netfs@lists.linux.dev, linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org, ceph-devel@vger.kernel.org, v9fs@lists.linux.dev, linux-erofs@lists.ozlabs.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Christian Brauner Subject: [PATCH v4 03/33] netfs: Fix a few minor bugs in netfs_page_mkwrite() Date: Fri, 8 Nov 2024 17:32:04 +0000 Message-ID: <20241108173236.1382366-4-dhowells@redhat.com> In-Reply-To: <20241108173236.1382366-1-dhowells@redhat.com> References: <20241108173236.1382366-1-dhowells@redhat.com> Precedence: bulk X-Mailing-List: v9fs@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 From: "Matthew Wilcox (Oracle)" We can't return with VM_FAULT_SIGBUS | VM_FAULT_LOCKED; the core code will not unlock the folio in this instance. Introduce a new "unlock" error exit to handle this case. Use it to handle the "folio is truncated" check, and change the "writeback interrupted by a fatal signal" to do a NOPAGE exit instead of letting the core code install the folio currently under writeback before killing the process. Signed-off-by: Matthew Wilcox (Oracle) Link: https://lore.kernel.org/r/20241005182307.3190401-3-willy@infradead.org Signed-off-by: Christian Brauner --- fs/netfs/buffered_write.c | 27 +++++++++++++-------------- 1 file changed, 13 insertions(+), 14 deletions(-) diff --git a/fs/netfs/buffered_write.c b/fs/netfs/buffered_write.c index b3910dfcb56d..ff2814da88b1 100644 --- a/fs/netfs/buffered_write.c +++ b/fs/netfs/buffered_write.c @@ -491,7 +491,9 @@ EXPORT_SYMBOL(netfs_file_write_iter); /* * Notification that a previously read-only page is about to become writable. - * Note that the caller indicates a single page of a multipage folio. + * The caller indicates the precise page that needs to be written to, but + * we only track group on a per-folio basis, so we block more often than + * we might otherwise. */ vm_fault_t netfs_page_mkwrite(struct vm_fault *vmf, struct netfs_group *netfs_group) { @@ -501,7 +503,7 @@ vm_fault_t netfs_page_mkwrite(struct vm_fault *vmf, struct netfs_group *netfs_gr struct address_space *mapping = file->f_mapping; struct inode *inode = file_inode(file); struct netfs_inode *ictx = netfs_inode(inode); - vm_fault_t ret = VM_FAULT_RETRY; + vm_fault_t ret = VM_FAULT_NOPAGE; int err; _enter("%lx", folio->index); @@ -510,21 +512,15 @@ vm_fault_t netfs_page_mkwrite(struct vm_fault *vmf, struct netfs_group *netfs_gr if (folio_lock_killable(folio) < 0) goto out; - if (folio->mapping != mapping) { - folio_unlock(folio); - ret = VM_FAULT_NOPAGE; - goto out; - } - - if (folio_wait_writeback_killable(folio)) { - ret = VM_FAULT_LOCKED; - goto out; - } + if (folio->mapping != mapping) + goto unlock; + if (folio_wait_writeback_killable(folio) < 0) + goto unlock; /* Can we see a streaming write here? */ if (WARN_ON(!folio_test_uptodate(folio))) { - ret = VM_FAULT_SIGBUS | VM_FAULT_LOCKED; - goto out; + ret = VM_FAULT_SIGBUS; + goto unlock; } group = netfs_folio_group(folio); @@ -559,5 +555,8 @@ vm_fault_t netfs_page_mkwrite(struct vm_fault *vmf, struct netfs_group *netfs_gr out: sb_end_pagefault(inode->i_sb); return ret; +unlock: + folio_unlock(folio); + goto out; } EXPORT_SYMBOL(netfs_page_mkwrite);