From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [f2fs-dev] [PATCH v2] f2fs: relax migratepage for atomic written page To: Jaegeuk Kim , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net References: <20170703230820.63929-1-jaegeuk@kernel.org> <20170706214926.GB395@jaegeuk-macbookpro.roam.corp.google.com> From: Chao Yu Message-ID: <4f92014b-5265-2c60-51a6-f80f34dd1418@kernel.org> Date: Fri, 7 Jul 2017 07:57:29 +0800 MIME-Version: 1.0 In-Reply-To: <20170706214926.GB395@jaegeuk-macbookpro.roam.corp.google.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: On 2017/7/7 5:49, Jaegeuk Kim wrote: > In order to avoid lock contention for atomic written pages, we'd better give > EBUSY in f2fs_migrate_page when mode is asynchronous. We expect it will be > released soon as transaction commits. > > Signed-off-by: Jaegeuk Kim Reviewed-by: Chao Yu > --- > > Change log from v1: > - return -EBUSY when mode is MIGRATE_ASYNC or MIGRATE_SYNC_LIGHT > > fs/f2fs/data.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index 85ac3a63cce6..74c31cb203e2 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -2206,8 +2206,12 @@ int f2fs_migrate_page(struct address_space *mapping, > BUG_ON(PageWriteback(page)); > > /* migrating an atomic written page is safe with the inmem_lock hold */ > - if (atomic_written && !mutex_trylock(&fi->inmem_lock)) > - return -EAGAIN; > + if (atomic_written) { > + if (mode != MIGRATE_SYNC) > + return -EBUSY; > + if (!mutex_trylock(&fi->inmem_lock)) > + return -EAGAIN; > + } > > /* > * A reference is expected if PagePrivate set when move mapping, >