From patchwork Wed Sep 11 02:51:58 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 11140227 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BCBB813BD for ; Wed, 11 Sep 2019 02:52:04 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7EDDE21D79 for ; Wed, 11 Sep 2019 02:52:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="LRu6iD6Z" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7EDDE21D79 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 8C4D16B0005; Tue, 10 Sep 2019 22:52:03 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 875086B0006; Tue, 10 Sep 2019 22:52:03 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 78A9B6B0007; Tue, 10 Sep 2019 22:52:03 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0226.hostedemail.com [216.40.44.226]) by kanga.kvack.org (Postfix) with ESMTP id 568C76B0005 for ; Tue, 10 Sep 2019 22:52:03 -0400 (EDT) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id ED22452CE for ; Wed, 11 Sep 2019 02:52:02 +0000 (UTC) X-FDA: 75921115284.19.group48_2ef1cb234684e X-Spam-Summary: 2,0,0,c066e619a23af2c1,d41d8cd98f00b204,willy@infradead.org,:josef@toxicpanda.com::linux-fsdevel@vger.kernel.org,RULES_HIT:41:355:379:800:960:973:988:989:1260:1277:1312:1313:1314:1345:1437:1516:1518:1519:1534:1541:1593:1594:1595:1596:1711:1730:1747:1777:1792:2393:2559:2562:3138:3139:3140:3141:3142:3352:3865:3867:3868:3870:3874:5007:6261:6653:7903:8957:10004:10400:11026:11473:11658:11914:12043:12296:12297:12438:12555:12679:13069:13311:13357:13439:13895:14096:14097:14181:14721:21080:21324:21451:21627:21740:21809:30054,0,RBL:198.137.202.133:@infradead.org:.lbl8.mailshell.net-62.14.0.100 64.201.201.201,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:25,LUA_SUMMARY:none X-HE-Tag: group48_2ef1cb234684e X-Filterd-Recvd-Size: 2678 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf19.hostedemail.com (Postfix) with ESMTP for ; Wed, 11 Sep 2019 02:52:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Type:MIME-Version:Message-ID: Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:References:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=PNNRbBM+ZsiFh/QzrWWJo+0Oaes86g1L+e4LhQmEhqk=; b=LRu6iD6ZpZkWtc3muCv5IpCHca ATXFJ7baQ1s0PJaPodE7T5TpCUji2Dsyx7KBeo/oYjefxqF9TQuZlJkVWaXg4ldVX0mst/PraGHOS J9f6r0LgVWtCl/onz/gkvz1iHEeYktQYLo1Knqn8UoVM65uWhjvTg23NqrYEq65F27IT2mHP6fXB1 oyMoCbw311mN1anXKXttFPb5deo6F1LpabmaPw3/C80evhPwHj7rBVKBPLxW5lJsEVFemizp32aSD +eQD7zcs06MCYxi0ELC/N+7FczQZbnuokJsC9kGK6VM/ulRovQvY1Z5wE/c8H9xszq9RXQjRjJz3I 3wpLmOuw==; Received: from willy by bombadil.infradead.org with local (Exim 4.92 #3 (Red Hat Linux)) id 1i7sje-0007ys-6T; Wed, 11 Sep 2019 02:51:58 +0000 Date: Tue, 10 Sep 2019 19:51:58 -0700 From: Matthew Wilcox To: Josef Bacik Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Subject: filemap_fault can lose errors Message-ID: <20190911025158.GG29434@bombadil.infradead.org> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.11.4 (2019-03-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: If we encounter an error on a page, we can lose the error if we've dropped the mmap_sem while we wait for the I/O. That can result in taking the fault multiple times, and retrying the read multiple times. Spotted by inspection. Signed-off-by: Matthew Wilcox (Oracle) Fixes: 6b4c9f446981 ("filemap: drop the mmap_sem for all blocking operations") diff --git a/mm/filemap.c b/mm/filemap.c index d0cf700bf201..37bd4aedfccf 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2615,6 +2615,8 @@ vm_fault_t filemap_fault(struct vm_fault *vmf) if (!PageUptodate(page)) error = -EIO; } + if (error < 0) + ret |= VM_FAULT_SIGBUS; if (fpin) goto out_retry; put_page(page); @@ -2622,9 +2624,9 @@ vm_fault_t filemap_fault(struct vm_fault *vmf) if (!error || error == AOP_TRUNCATED_PAGE) goto retry_find; - /* Things didn't work out. Return zero to tell the mm layer so. */ + /* Things didn't work out. */ shrink_readahead_size_eio(file, ra); - return VM_FAULT_SIGBUS; + return ret; out_retry: /*