From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Thu, 9 Feb 2017 13:17:28 +0100 From: Jan Kara To: Richard Weinberger Cc: Jan Kara , linux-fsdevel@vger.kernel.org, Christoph Hellwig , linux-block@vger.kernel.org, Artem Bityutskiy , Adrian Hunter , linux-mtd@lists.infradead.org Subject: Re: [PATCH 22/24] ubifs: Convert to separately allocated bdi Message-ID: <20170209121728.GE16825@quack2.suse.cz> References: <20170202173422.3240-1-jack@suse.cz> <20170202173422.3240-23-jack@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Wed 08-02-17 12:24:00, Richard Weinberger wrote: > Am 02.02.2017 um 18:34 schrieb Jan Kara: > > Allocate struct backing_dev_info separately instead of embedding it > > inside the superblock. This unifies handling of bdi among users. > > > > CC: Richard Weinberger > > CC: Artem Bityutskiy > > CC: Adrian Hunter > > CC: linux-mtd@lists.infradead.org > > Signed-off-by: Jan Kara > > --- > > fs/ubifs/super.c | 23 +++++++---------------- > > fs/ubifs/ubifs.h | 3 --- > > 2 files changed, 7 insertions(+), 19 deletions(-) > > > > diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c > > index e08aa04fc835..34810eb52b22 100644 > > --- a/fs/ubifs/super.c > > +++ b/fs/ubifs/super.c > > @@ -1827,7 +1827,6 @@ static void ubifs_put_super(struct super_block *sb) > > } > > > > ubifs_umount(c); > > - bdi_destroy(&c->bdi); > > ubi_close_volume(c->ubi); > > mutex_unlock(&c->umount_mutex); > > } > > @@ -2019,29 +2018,23 @@ static int ubifs_fill_super(struct super_block *sb, void *data, int silent) > > goto out; > > } > > > > + err = ubifs_parse_options(c, data, 0); > > + if (err) > > + goto out_close; > > + > > /* > > * UBIFS provides 'backing_dev_info' in order to disable read-ahead. For > > * UBIFS, I/O is not deferred, it is done immediately in readpage, > > * which means the user would have to wait not just for their own I/O > > * but the read-ahead I/O as well i.e. completely pointless. > > * > > - * Read-ahead will be disabled because @c->bdi.ra_pages is 0. > > + * Read-ahead will be disabled because @sb->s_bdi->ra_pages is 0. > > */ > > - c->bdi.name = "ubifs", > > - c->bdi.capabilities = 0; > > So ->capabilities is now zero by default since you use __GFP_ZERO in > bdi_alloc(). > At least for UBIFS I'll add a comment on this, otherwise it is not so > clear that UBIFS wants a BDI with no capabilities and how it achieves that. OK, I've modified the comment to: * Read-ahead will be disabled because @sb->s_bdi->ra_pages is 0. Also * @sb->s_bdi->capabilities are initialized to 0 so there won't be any * writeback happening. */ > Acked-by: Richard Weinberger Thanks. Honza -- Jan Kara SUSE Labs, CR