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 E2C5AC77B61 for ; Sat, 29 Apr 2023 01:20:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E1E0D6B0072; Fri, 28 Apr 2023 21:20:49 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DCE906B0074; Fri, 28 Apr 2023 21:20:49 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C96EC6B0075; Fri, 28 Apr 2023 21:20:49 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id BA68B6B0072 for ; Fri, 28 Apr 2023 21:20:49 -0400 (EDT) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 83ED81401C2 for ; Sat, 29 Apr 2023 01:20:49 +0000 (UTC) X-FDA: 80732674218.23.F6F8C39 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf23.hostedemail.com (Postfix) with ESMTP id 69BAF140011 for ; Sat, 29 Apr 2023 01:20:45 +0000 (UTC) Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=Fu1HC8bU; spf=none (imf23.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1682731247; h=from:from: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=BaIEj2paZYE/uU2XkcW2I8y0R+043vPSdJ9uniAsh0U=; b=L0+6mvJxF8rTXYo/r/awy0/GE6mpJzTGd/7ZiZS2NFs83HTPCPHKJpI6Q7JdM9Mb8yFK5+ /6ABMxgR9eEMyeo2OOICHxcPsnrv6InI6S3k+SGxxqmuUCAw2uyCXRl9n/FGvRSQhYDhxH 6lSx85caGGRDdIW7xzmpoGfeUhblJFk= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=Fu1HC8bU; spf=none (imf23.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1682731247; a=rsa-sha256; cv=none; b=cwYQxuNgAdCZzHbpZdVe56KgzfguyfLpCeZp/5FKU2NZG2XfJ6pdT21KfosEsR4NRiRFlw Wj8V8evJBS9CokzfzojF+K5XxL4BPLrH0JkRWaK3wwNpbuQTP0517LBtEMWTr38IQO3TJy aug9WCzs4/9RzTYivjxB1vAdzHcOE90= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=BaIEj2paZYE/uU2XkcW2I8y0R+043vPSdJ9uniAsh0U=; b=Fu1HC8bUG02gPzRUECQ6ysoDOs TKxxmHyyETr+yycfGwhDUSeMV9sMGtard9Y9x6iKaNQrEjTizdLrKfJqajF9FFqYC0FcARAJBzYa7 QmDsQyBNdOb1YuUCNd0jOstr5EUUo+rkNCx68RH6ucdm2kUyF+oMxXeeKPlKwzVpW0Vs2hPKvplhl zBtm35j8R0bVRMTrCVHq8C/RgnPDcuECqaH7jXz7zqz1yCjsGcZrjUCYWzP4bIZvk1TGoHdLj7G7Z Cb6pFJcswSczJFWlK1VT+VeMjZesZ6hXXpaiKMKi4EFId/Pr54k+/0BaupArt2vjbPiYkfYlfTNsz jgLrdWuA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1psZG6-0059h2-19; Sat, 29 Apr 2023 01:20:18 +0000 Date: Sat, 29 Apr 2023 02:20:17 +0100 From: Matthew Wilcox To: Luis Chamberlain Cc: Christoph Hellwig , Pankaj Raghav , Daniel Gomez , Jens Axboe , Miklos Szeredi , "Darrick J. Wong" , Andrew Morton , David Howells , 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 17/17] fs: add CONFIG_BUFFER_HEAD Message-ID: References: <20230424054926.26927-1-hch@lst.de> <20230424054926.26927-18-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 69BAF140011 X-Stat-Signature: xatra896ir9j6ndoau5mhu3rqwr59kpk X-HE-Tag: 1682731245-898660 X-HE-Meta: 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 lO4tzheD y39P90p5ikb/JpWgPQiMgKBxf6AaXIVKS1+SSGGdt5wkM/MxGOfkN0UsXiaMeaDxgL2D3GIkQbaJc3I1FS1wnIJ4Cd30TWTpybMiW6Uvz715rlgmQgJ00VcWybv28rWdV0XR62vVEXGMYeov8pg6WZfTA8pMplVMX2ZrbVDnDKFHqJMNkwNcXOBiWjg== 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 Fri, Apr 28, 2023 at 05:11:57PM -0700, Luis Chamberlain wrote: > [ 11.245248] BUG: kernel NULL pointer dereference, address: 0000000000000000 > [ 11.254581] #PF: supervisor read access in kernel mode > [ 11.257387] #PF: error_code(0x0000) - not-present page > [ 11.260921] PGD 0 P4D 0 > [ 11.262600] Oops: 0000 [#1] PREEMPT SMP PTI > [ 11.264993] CPU: 7 PID: 198 Comm: (udev-worker) Not tainted 6.3.0-large-block-20230426 #2 > [ 11.269385] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-debian-1.16.0-5 04/01/2014 > [ 11.275054] RIP: 0010:iomap_page_create.isra.0+0xc/0xd0 > [ 11.277924] Code: 41 5e 41 5f c3 cc cc cc cc 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 41 54 55 48 89 f5 53 <48> 8b 06 48 c1 e8 0d 89 c6 83 e6 01 0f 84 a1 00 00 00 4c 8b 65 28 > [ 11.287293] RSP: 0018:ffffb0f0805ef9d8 EFLAGS: 00010293 > [ 11.289964] RAX: ffff9de3c1fa8388 RBX: ffffb0f0805efa78 RCX: 000000037ffe0000 > [ 11.293212] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000000000d > [ 11.296485] RBP: 0000000000000000 R08: 0000000000021000 R09: ffffffff9c733b20 > [ 11.299724] R10: 0000000000000001 R11: 000000000000c000 R12: 0000000000000000 > [ 11.302974] R13: ffffffff9be96260 R14: ffffb0f0805efa58 R15: 0000000000000000 RSI is argument 2, which is folio. Code starting with the faulting instruction =========================================== 0: 48 8b 06 mov (%rsi),%rax 3: 48 c1 e8 0d shr $0xd,%rax Looks to me like a NULL folio was passed into iomap_page_create(). > [ 11.306206] FS: 00007f03ea8368c0(0000) GS:ffff9de43bdc0000(0000) knlGS:0000000000000000 > [ 11.309949] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 11.312464] CR2: 0000000000000000 CR3: 0000000117ec6006 CR4: 0000000000770ee0 > [ 11.315442] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 11.318310] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > [ 11.321010] PKRU: 55555554 > [ 11.322212] Call Trace: > [ 11.323224] > [ 11.324146] iomap_readpage_iter+0x96/0x300 > [ 11.325694] iomap_readahead+0x174/0x2d0 > [ 11.327129] read_pages+0x69/0x1f0 > [ 11.329751] page_cache_ra_unbounded+0x187/0x1d0 ... that shouldn't be possible. read_pages() allocates pages, puts them in the page cache and tells the filesystem to fill them in. In your patches, did you call mapping_set_large_folios() anywhere?