Return-Path: linux-nfs-owner@vger.kernel.org Received: from cantor2.suse.de ([195.135.220.15]:58558 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752345AbbANOFv (ORCPT ); Wed, 14 Jan 2015 09:05:51 -0500 Date: Wed, 14 Jan 2015 15:05:46 +0100 From: Jan Kara To: Christoph Hellwig Cc: Jens Axboe , David Howells , Tejun Heo , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-mtd@lists.infradead.org, linux-nfs@vger.kernel.org, ceph-devel@vger.kernel.org Subject: Re: [PATCH 12/12] fs: remove default_backing_dev_info Message-ID: <20150114140546.GM10215@quack.suse.cz> References: <1421228561-16857-1-git-send-email-hch@lst.de> <1421228561-16857-13-git-send-email-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1421228561-16857-13-git-send-email-hch@lst.de> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Wed 14-01-15 10:42:41, Christoph Hellwig wrote: > Now that default_backing_dev_info is not used for writeback purposes we can > git rid of it easily: > > - instead of using it's name for tracing unregistered bdi we just use > "unknown" > - btrfs and ceph can just assign the default read ahead window themselves > like several other filesystems already do. > - we can assign noop_backing_dev_info as the default one in alloc_super. > All filesystems already either assigned their own or > noop_backing_dev_info. > > Signed-off-by: Christoph Hellwig > Reviewed-by: Tejun Heo Looks good. You can add: Reviewed-by: Jan Kara Honza > --- > fs/btrfs/disk-io.c | 2 +- > fs/ceph/super.c | 2 +- > fs/super.c | 8 ++------ > include/linux/backing-dev.h | 1 - > include/trace/events/writeback.h | 6 ++---- > mm/backing-dev.c | 9 --------- > 6 files changed, 6 insertions(+), 22 deletions(-) > > diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c > index 1ec872e..1afb182 100644 > --- a/fs/btrfs/disk-io.c > +++ b/fs/btrfs/disk-io.c > @@ -1719,7 +1719,7 @@ static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi) > if (err) > return err; > > - bdi->ra_pages = default_backing_dev_info.ra_pages; > + bdi->ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE; > bdi->congested_fn = btrfs_congested_fn; > bdi->congested_data = info; > return 0; > diff --git a/fs/ceph/super.c b/fs/ceph/super.c > index e350cc1..5ae6258 100644 > --- a/fs/ceph/super.c > +++ b/fs/ceph/super.c > @@ -899,7 +899,7 @@ static int ceph_register_bdi(struct super_block *sb, > >> PAGE_SHIFT; > else > fsc->backing_dev_info.ra_pages = > - default_backing_dev_info.ra_pages; > + VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE; > > err = bdi_register(&fsc->backing_dev_info, NULL, "ceph-%ld", > atomic_long_inc_return(&bdi_seq)); > diff --git a/fs/super.c b/fs/super.c > index eae088f..3b4dada 100644 > --- a/fs/super.c > +++ b/fs/super.c > @@ -185,8 +185,8 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags) > } > init_waitqueue_head(&s->s_writers.wait); > init_waitqueue_head(&s->s_writers.wait_unfrozen); > + s->s_bdi = &noop_backing_dev_info; > s->s_flags = flags; > - s->s_bdi = &default_backing_dev_info; > INIT_HLIST_NODE(&s->s_instances); > INIT_HLIST_BL_HEAD(&s->s_anon); > INIT_LIST_HEAD(&s->s_inodes); > @@ -863,10 +863,7 @@ EXPORT_SYMBOL(free_anon_bdev); > > int set_anon_super(struct super_block *s, void *data) > { > - int error = get_anon_bdev(&s->s_dev); > - if (!error) > - s->s_bdi = &noop_backing_dev_info; > - return error; > + return get_anon_bdev(&s->s_dev); > } > > EXPORT_SYMBOL(set_anon_super); > @@ -1111,7 +1108,6 @@ mount_fs(struct file_system_type *type, int flags, const char *name, void *data) > sb = root->d_sb; > BUG_ON(!sb); > WARN_ON(!sb->s_bdi); > - WARN_ON(sb->s_bdi == &default_backing_dev_info); > sb->s_flags |= MS_BORN; > > error = security_sb_kern_mount(sb, flags, secdata); > diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h > index ed59dee..d94077f 100644 > --- a/include/linux/backing-dev.h > +++ b/include/linux/backing-dev.h > @@ -241,7 +241,6 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); > #define BDI_CAP_NO_ACCT_AND_WRITEBACK \ > (BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_ACCT_WB) > > -extern struct backing_dev_info default_backing_dev_info; > extern struct backing_dev_info noop_backing_dev_info; > > int writeback_in_progress(struct backing_dev_info *bdi); > diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h > index 74f5207..0e93109 100644 > --- a/include/trace/events/writeback.h > +++ b/include/trace/events/writeback.h > @@ -156,10 +156,8 @@ DECLARE_EVENT_CLASS(writeback_work_class, > __field(int, reason) > ), > TP_fast_assign( > - struct device *dev = bdi->dev; > - if (!dev) > - dev = default_backing_dev_info.dev; > - strncpy(__entry->name, dev_name(dev), 32); > + strncpy(__entry->name, > + bdi->dev ? dev_name(bdi->dev) : "(unknown)", 32); > __entry->nr_pages = work->nr_pages; > __entry->sb_dev = work->sb ? work->sb->s_dev : 0; > __entry->sync_mode = work->sync_mode; > diff --git a/mm/backing-dev.c b/mm/backing-dev.c > index 3ebba25..c49026d 100644 > --- a/mm/backing-dev.c > +++ b/mm/backing-dev.c > @@ -14,12 +14,6 @@ > > static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0); > > -struct backing_dev_info default_backing_dev_info = { > - .name = "default", > - .ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE, > -}; > -EXPORT_SYMBOL_GPL(default_backing_dev_info); > - > struct backing_dev_info noop_backing_dev_info = { > .name = "noop", > .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK, > @@ -250,9 +244,6 @@ static int __init default_bdi_init(void) > if (!bdi_wq) > return -ENOMEM; > > - err = bdi_init(&default_backing_dev_info); > - if (!err) > - bdi_register(&default_backing_dev_info, NULL, "default"); > err = bdi_init(&noop_backing_dev_info); > > return err; > -- > 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Jan Kara SUSE Labs, CR