From patchwork Thu Dec 21 16:30:55 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 10128035 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id E54C760318 for ; Thu, 21 Dec 2017 16:31:08 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D8D5529D61 for ; Thu, 21 Dec 2017 16:31:08 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CD5D229D89; Thu, 21 Dec 2017 16:31:08 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 74CFC29D83 for ; Thu, 21 Dec 2017 16:31:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753255AbdLUQbG (ORCPT ); Thu, 21 Dec 2017 11:31:06 -0500 Received: from mx2.suse.de ([195.135.220.15]:51554 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753228AbdLUQbE (ORCPT ); Thu, 21 Dec 2017 11:31:04 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id B3567ADEC; Thu, 21 Dec 2017 16:31:02 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 221C31E0F2E; Thu, 21 Dec 2017 17:31:02 +0100 (CET) From: Jan Kara To: Cc: Ted Tso , Ross Zwisler , Dan Williams , , linux-nvdimm@lists.01.org, Jan Kara Subject: [PATCH 2/2] ext4: Fix ENOSPC handling in DAX page fault handler Date: Thu, 21 Dec 2017 17:30:55 +0100 Message-Id: <20171221163055.3943-3-jack@suse.cz> X-Mailer: git-send-email 2.12.3 In-Reply-To: <20171221163055.3943-1-jack@suse.cz> References: <20171221163055.3943-1-jack@suse.cz> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When allocation of underlying block for a page fault fails, we fail the fault with SIGBUS. However we may well hit ENOSPC just due to lots of free blocks being held by the running / committing transaction. So propagate the error from ext4_iomap_begin() and implement do standard allocation retry loop in ext4_dax_huge_fault(). Signed-off-by: Jan Kara Reviewed-by: Ross Zwisler --- fs/ext4/file.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 1c7cd882d998..fb6f023622fe 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -280,7 +280,8 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from) static int ext4_dax_huge_fault(struct vm_fault *vmf, enum page_entry_size pe_size) { - int result; + int result, error = 0; + int retries = 0; handle_t *handle = NULL; struct inode *inode = file_inode(vmf->vma->vm_file); struct super_block *sb = inode->i_sb; @@ -304,6 +305,7 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf, sb_start_pagefault(sb); file_update_time(vmf->vma->vm_file); down_read(&EXT4_I(inode)->i_mmap_sem); +retry: handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE, EXT4_DATA_TRANS_BLOCKS(sb)); if (IS_ERR(handle)) { @@ -314,9 +316,13 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf, } else { down_read(&EXT4_I(inode)->i_mmap_sem); } - result = dax_iomap_fault(vmf, pe_size, &pfn, NULL, &ext4_iomap_ops); + result = dax_iomap_fault(vmf, pe_size, &pfn, &error, &ext4_iomap_ops); if (write) { ext4_journal_stop(handle); + + if ((result & VM_FAULT_ERROR) && error == -ENOSPC && + ext4_should_retry_alloc(sb, &retries)) + goto retry; /* Handling synchronous page fault? */ if (result & VM_FAULT_NEEDDSYNC) result = dax_finish_sync_fault(vmf, pe_size, pfn);