From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755033AbcDAKOz (ORCPT ); Fri, 1 Apr 2016 06:14:55 -0400 Received: from mx2.suse.de ([195.135.220.15]:56137 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754629AbcDAKOy (ORCPT ); Fri, 1 Apr 2016 06:14:54 -0400 Subject: Re: [PATCH 2/2] UBIFS: Implement ->migratepage() To: Richard Weinberger , linux-fsdevel@vger.kernel.org References: <1459461513-31765-1-git-send-email-richard@nod.at> <1459461513-31765-3-git-send-email-richard@nod.at> Cc: linux-mtd@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, boris.brezillon@free-electrons.com, maxime.ripard@free-electrons.com, david@sigma-star.at, david@fromorbit.com, dedekind1@gmail.com, alex@nextthing.co, akpm@linux-foundation.org, sasha.levin@oracle.com, iamjoonsoo.kim@lge.com, rvaswani@codeaurora.org, tony.luck@intel.com, shailendra.capricorn@gmail.com, kirill.shutemov@linux.intel.com, hch@infradead.org, hughd@google.com, mgorman@techsingularity.net From: Vlastimil Babka Message-ID: <56FE4A1B.606@suse.cz> Date: Fri, 1 Apr 2016 12:14:51 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <1459461513-31765-3-git-send-email-richard@nod.at> Content-Type: text/plain; charset=iso-8859-2; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/31/2016 11:58 PM, Richard Weinberger wrote: > From: "Kirill A. Shutemov" > > During page migrations UBIFS might get confused > and the following assert triggers: > UBIFS assert failed in ubifs_set_page_dirty at 1451 (pid 436) It would be useful to have the full trace in changelog. > UBIFS is using PagePrivate() which can have different meanings across > filesystems. Therefore the generic page migration code cannot handle this > case correctly. > We have to implement our own migration function which basically does a > plain copy but also duplicates the page private flag. > UBIFS is not a block device filesystem and cannot use buffer_migrate_page(). > > Signed-off-by: Kirill A. Shutemov > [rw: Massaged changelog] > Signed-off-by: Richard Weinberger Stable? > Signed-off-by: Richard Weinberger > --- > fs/ubifs/file.c | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) > > diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c > index 065c88f..5eea5f5 100644 > --- a/fs/ubifs/file.c > +++ b/fs/ubifs/file.c > @@ -52,6 +52,7 @@ > #include "ubifs.h" > #include > #include > +#include > > static int read_block(struct inode *inode, void *addr, unsigned int block, > struct ubifs_data_node *dn) > @@ -1452,6 +1453,24 @@ static int ubifs_set_page_dirty(struct page *page) > return ret; > } > > +static int ubifs_migrate_page(struct address_space *mapping, > + struct page *newpage, struct page *page, enum migrate_mode mode) > +{ > + int rc; > + > + rc = migrate_page_move_mapping(mapping, newpage, page, NULL, mode, 0); > + if (rc != MIGRATEPAGE_SUCCESS) > + return rc; > + > + if (PagePrivate(page)) { > + ClearPagePrivate(page); > + SetPagePrivate(newpage); > + } > + > + migrate_page_copy(newpage, page); > + return MIGRATEPAGE_SUCCESS; > +} > + > static int ubifs_releasepage(struct page *page, gfp_t unused_gfp_flags) > { > /* > @@ -1591,6 +1610,7 @@ const struct address_space_operations ubifs_file_address_operations = { > .write_end = ubifs_write_end, > .invalidatepage = ubifs_invalidatepage, > .set_page_dirty = ubifs_set_page_dirty, > + .migratepage = ubifs_migrate_page, > .releasepage = ubifs_releasepage, > }; > >