From patchwork Sat Mar 9 12:07:21 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Aneesh Kumar K.V" X-Patchwork-Id: 10845909 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 42E571390 for ; Sat, 9 Mar 2019 12:07:43 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 32C522D9D8 for ; Sat, 9 Mar 2019 12:07:43 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 269912E12E; Sat, 9 Mar 2019 12:07:43 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable 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 C250E2D9D8 for ; Sat, 9 Mar 2019 12:07:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726208AbfCIMHj (ORCPT ); Sat, 9 Mar 2019 07:07:39 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:55258 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725841AbfCIMHj (ORCPT ); Sat, 9 Mar 2019 07:07:39 -0500 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x29BsFgH112043 for ; Sat, 9 Mar 2019 07:07:37 -0500 Received: from e32.co.us.ibm.com (e32.co.us.ibm.com [32.97.110.150]) by mx0a-001b2d01.pphosted.com with ESMTP id 2r4a8m4hth-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Sat, 09 Mar 2019 07:07:37 -0500 Received: from localhost by e32.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Sat, 9 Mar 2019 12:07:33 -0000 Received: from b03ledav005.gho.boulder.ibm.com (b03ledav005.gho.boulder.ibm.com [9.17.130.236]) by b03cxnp08027.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x29C7Wpv52822224 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 9 Mar 2019 12:07:32 GMT Received: from b03ledav005.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EA445BE054; Sat, 9 Mar 2019 12:07:31 +0000 (GMT) Received: from b03ledav005.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 80886BE05A; Sat, 9 Mar 2019 12:07:28 +0000 (GMT) Received: from skywalker.ibmuc.com (unknown [9.85.71.67]) by b03ledav005.gho.boulder.ibm.com (Postfix) with ESMTP; Sat, 9 Mar 2019 12:07:28 +0000 (GMT) From: "Aneesh Kumar K.V" To: dan.j.williams@intel.com, Ross Zwisler , Jan Kara Cc: linux-nvdimm@lists.01.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-fsdevel@vger.kernel.org, Alexander Viro , "Aneesh Kumar K.V" Subject: [PATCH v2] fs/dax: deposit pagetable even when installing zero page Date: Sat, 9 Mar 2019 17:37:21 +0530 X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 19030912-0004-0000-0000-000014EC02DD X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010732; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000281; SDB=6.01171848; UDB=6.00612557; IPR=6.00952491; MB=3.00025905; MTD=3.00000008; XFM=3.00000015; UTC=2019-03-09 12:07:35 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19030912-0005-0000-0000-00008AD90E02 Message-Id: <20190309120721.21416-1-aneesh.kumar@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-03-09_11:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=2 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1903090092 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 Architectures like ppc64 use the deposited page table to store hardware page table slot information. Make sure we deposit a page table when using zero page at the pmd level for hash. Without this we hit Unable to handle kernel paging request for data at address 0x00000000 Faulting instruction address: 0xc000000000082a74 Oops: Kernel access of bad area, sig: 11 [#1] .... NIP [c000000000082a74] __hash_page_thp+0x224/0x5b0 LR [c0000000000829a4] __hash_page_thp+0x154/0x5b0 Call Trace: hash_page_mm+0x43c/0x740 do_hash_page+0x2c/0x3c copy_from_iter_flushcache+0xa4/0x4a0 pmem_copy_from_iter+0x2c/0x50 [nd_pmem] dax_copy_from_iter+0x40/0x70 dax_iomap_actor+0x134/0x360 iomap_apply+0xfc/0x1b0 dax_iomap_rw+0xac/0x130 ext4_file_write_iter+0x254/0x460 [ext4] __vfs_write+0x120/0x1e0 vfs_write+0xd8/0x220 SyS_write+0x6c/0x110 system_call+0x3c/0x130 Fixes: b5beae5e224f ("powerpc/pseries: Add driver for PAPR SCM regions") Reviewed-by: Jan Kara Signed-off-by: Aneesh Kumar K.V --- Changes from v1: * Add reviewed-by: * Add Fixes: fs/dax.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/fs/dax.c b/fs/dax.c index 6959837cc465..01bfb2ac34f9 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -33,6 +33,7 @@ #include #include #include +#include #include "internal.h" #define CREATE_TRACE_POINTS @@ -1410,7 +1411,9 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, { struct address_space *mapping = vmf->vma->vm_file->f_mapping; unsigned long pmd_addr = vmf->address & PMD_MASK; + struct vm_area_struct *vma = vmf->vma; struct inode *inode = mapping->host; + pgtable_t pgtable = NULL; struct page *zero_page; spinlock_t *ptl; pmd_t pmd_entry; @@ -1425,12 +1428,22 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, *entry = dax_insert_entry(xas, mapping, vmf, *entry, pfn, DAX_PMD | DAX_ZERO_PAGE, false); + if (arch_needs_pgtable_deposit()) { + pgtable = pte_alloc_one(vma->vm_mm); + if (!pgtable) + return VM_FAULT_OOM; + } + ptl = pmd_lock(vmf->vma->vm_mm, vmf->pmd); if (!pmd_none(*(vmf->pmd))) { spin_unlock(ptl); goto fallback; } + if (pgtable) { + pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable); + mm_inc_nr_ptes(vma->vm_mm); + } pmd_entry = mk_pmd(zero_page, vmf->vma->vm_page_prot); pmd_entry = pmd_mkhuge(pmd_entry); set_pmd_at(vmf->vma->vm_mm, pmd_addr, vmf->pmd, pmd_entry); @@ -1439,6 +1452,8 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, return VM_FAULT_NOPAGE; fallback: + if (pgtable) + pte_free(vma->vm_mm, pgtable); trace_dax_pmd_load_hole_fallback(inode, vmf, zero_page, *entry); return VM_FAULT_FALLBACK; }