From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id DFC68C77B7A for ; Wed, 24 May 2023 22:23:33 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 44074900003; Wed, 24 May 2023 18:23:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3EFCE900002; Wed, 24 May 2023 18:23:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2B800900003; Wed, 24 May 2023 18:23:33 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 1E2F3900002 for ; Wed, 24 May 2023 18:23:33 -0400 (EDT) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id E23C880A1F for ; Wed, 24 May 2023 22:23:32 +0000 (UTC) X-FDA: 80826576264.25.8AC0CDA Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf15.hostedemail.com (Postfix) with ESMTP id 48750A0008 for ; Wed, 24 May 2023 22:23:31 +0000 (UTC) Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=Olg5NsAi; dmarc=fail reason="No valid SPF, DKIM not aligned (relaxed)" header.from=kernel.org (policy=none); spf=none (imf15.hostedemail.com: domain of mcgrof@infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=mcgrof@infradead.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1684967011; a=rsa-sha256; cv=none; b=iyKUAuVnxGpRXtiy8Y+D5Loeg4347lnFjCgMXS8YEGt/ZyPVFI85f7Ls2AHPKCcwELVJcg +zHseHJ006+kQC7ERJBVhMiNhjE7rGdPNiHHKw20muyxYq3TVaJYyjeiqt8qUqWQ0B8arq H0208QNb/T9F+4q5NFIQ4B5HqaBoN58= ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=Olg5NsAi; dmarc=fail reason="No valid SPF, DKIM not aligned (relaxed)" header.from=kernel.org (policy=none); spf=none (imf15.hostedemail.com: domain of mcgrof@infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=mcgrof@infradead.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1684967011; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=6a4TWuzTGi7+tMMLrCXx2xS2HLm+fpIBXBWX9SQFhJc=; b=XC1l4pCd62X+RXrLXPgq8R4WoWkHYwFajoF5dc2S/UUq4RgFokjOUPh/Egj9+VFYXBRIbm GgDDjec9xyd/AAAEnKDKr/kgeGbpEDjojOM5kNYaadsS3+gVnFdrgvxie2z6cYB3Pd/Ghr qiAbh5YE9WpYP6YIpUqpVNcDu9NgmrQ= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=6a4TWuzTGi7+tMMLrCXx2xS2HLm+fpIBXBWX9SQFhJc=; b=Olg5NsAiR4MXUKxEfN0JWQ26G+ 48QUUb0p3dP2AO5RET1yB+OlmxpPgfW/OAuL8L3TmcLxGehBJ8zrOmr2kBjQvXnIDe74EGIXQUw5V jrolzbG8yKU05ZkW5mpKw/LmaGIzjIW2osv7EnQcuMT1PVUpROY1wInr2AXsx/P1CtXqq68pLnhwc o//oJNGyzcS02XIm8oZ0EkYqFxmeJvu+ZYfriDV2Rx6DKfxLwq6Z2WZASZL/SOiLmZyzD7t1ZY8rR AcKIKrMHyGez7UPTrzHiDlh7DZpdMV2McGOt3pus8tAT+JlDrTHSf6mbJJPR2Ulm/XYS7au9Vkv2O 3mANUUxw==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1q1wsv-00EnXL-1n; Wed, 24 May 2023 22:23:09 +0000 Date: Wed, 24 May 2023 15:23:09 -0700 From: Luis Chamberlain To: Christoph Hellwig , Daniel Gomez , Pankaj Raghav , Ming Lei Cc: Jens Axboe , Miklos Szeredi , "Darrick J. Wong" , Andrew Morton , David Howells , Matthew Wilcox , linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, ceph-devel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, cluster-devel@redhat.com, linux-xfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 14/17] block: open code __generic_file_write_iter for blkdev writes Message-ID: References: <20230424054926.26927-1-hch@lst.de> <20230424054926.26927-15-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230424054926.26927-15-hch@lst.de> X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 48750A0008 X-Stat-Signature: h1dfo68ccrftwinzriso5nf3zkyaym7k X-HE-Tag: 1684967011-839457 X-HE-Meta: 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 xbdhseZw ClmUEVLrNBNSaILjZ07IZFFofAuBrvqANELS5SKKkvZidYiTgWUAQuxGU0oBNZzc6pY8TMhk1Rqx9EtOd+WYVl6NsrrDJm7e0gHvDCNIEZKd+SWtrMIhTbvCh9WubSXY4jiFn064t9Zjl29oyQ04G+pxEh+utHzo5EX6gFHIrczvmJjVNinI3tuwPCCvXuOO6W/AuhEwf9hj6my6D5eIJkW4DQ3q0clqkPMeKPGoWRNcK6vXO69BeOXdVzZYjMpc/O7HNHI404xcw0vt8fqV+wTflfe9vfCysetqW59HrcmxVtc5ng8UkxXrHteREyp6JlQsXIv5a+BjoXju3/vXtG1NEeF6Tq4SG03DIRUZv2HLFRNCkUvOXBGvY4QAjI761KQ8W 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: On Mon, Apr 24, 2023 at 07:49:23AM +0200, Christoph Hellwig wrote: > Open code __generic_file_write_iter to remove the indirect call into > ->direct_IO and to prepare using the iomap based write code. > > Signed-off-by: Christoph Hellwig > --- > block/fops.c | 46 ++++++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 44 insertions(+), 2 deletions(-) > > diff --git a/block/fops.c b/block/fops.c > index b670aa7c5bb745..fd510b6142bd57 100644 > --- a/block/fops.c > +++ b/block/fops.c > @@ -508,6 +508,29 @@ static int blkdev_close(struct inode *inode, struct file *filp) > return 0; > } > > +static ssize_t > +blkdev_direct_write(struct kiocb *iocb, struct iov_iter *from) > +{ > + size_t count = iov_iter_count(from); > + ssize_t written; > + > + written = kiocb_invalidate_pages(iocb, count); > + if (written) { > + if (written == -EBUSY) > + return 0; > + return written; > + } > + > + written = blkdev_direct_IO(iocb, from); > + if (written > 0) { > + kiocb_invalidate_post_write(iocb, count); > + iocb->ki_pos += written; > + } Written can be negative here after blkdev_direct_IO() > + if (written != -EIOCBQUEUED) > + iov_iter_revert(from, count - written - iov_iter_count(from)); And we'll then use it here on iov_iter_revert() and this can crash on with some values. For example this can crash on a 4k write attempt on a 32k drive when experimenting wit large block sizes. kernel BUG at lib/iov_iter.c:999! invalid opcode: 0000 [#1] PREEMPT SMP PTI CPU: 4 PID: 949 Comm: fio Not tainted 6.3.0-large-block-20230426-dirty#28 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-debian-1.16.0-5 04/01/2014 +RIP: 0010:iov_iter_revert.part.0+0x16e/0x170 Code: f9 40 a2 63 af 74 07 03 56 08 89 d8 29 d0 89 45 08 44 89 6d 20 RSP: 0018:ffffaa52006cfc60 EFLAGS: 00010246 RAX: 0000000000000016 RBX: 0000000000000016 RCX: 0000000000000000 RDX: 0000000000000004 RSI: 0000000000000006 RDI: ffffaa52006cfd08 RBP: ffffaa52006cfd08 R08: 0000000000000000 R09: ffffaa52006cfb40 R10: 0000000000000003 R11: ffffffffafcc21e8 R12: 0000000000004000 R13: 0000000000003fea R14: ffff9de3d7565e00 R15: ffff9de3c1f68600 FS: 00007f8bfe726c40(0000) GS:ffff9de43bd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8bf5eadd68 CR3: 0000000102c76001 CR4: 0000000000770ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: blkdev_direct_write+0xf0/0x160 blkdev_write_iter+0x11b/0x230 io_write+0x10c/0x420 ? kmem_cache_alloc_bulk+0x2a1/0x410 ? fget+0x79/0xb0 io_issue_sqe+0x60/0x3b0 ? io_prep_rw+0x5a/0x190 io_submit_sqes+0x1e6/0x640 __do_sys_io_uring_enter+0x54c/0xb90 ? handle_mm_fault+0x9a/0x340 ? preempt_count_add+0x47/0xa0 ? up_read+0x37/0x70 ? do_user_addr_fault+0x27c/0x780 do_syscall_64+0x37/0x90 entry_SYSCALL_64_after_hw Although I fixed it with an early check on this routine with: if (count < bdev_logical_block_size(bdev)) return -EINVAL; I think this can just be fixed by also using the alignment check earier here: if (blkdev_dio_unaligned(bdev, pos, iter)) return -EINVAL; Luis