Re: [PATCH 05/13] bdi: initialize ->ra_pages and ->io_pages in bdi_init

From: Mike Marshall <hubcap@omnibond.com>
To: Christoph Hellwig <hch@lst.de>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	Mike Marshall <hubcapsc@gmail.com>
Subject: Re: [PATCH 05/13] bdi: initialize ->ra_pages and ->io_pages in bdi_init
Date: Thu, 24 Sep 2020 11:24:19 -0400	[thread overview]
Message-ID: <CAOg9mSRzpLvydt=eN19z0=PjsLZpiTGO5VMB+nr_ZKTutsG+eA@mail.gmail.com> (raw)
In-Reply-To: <20200924065140.726436-6-hch@lst.de>

Since this patch set will affect orangefs, I was going to apply them to
Linux 5.9-rc6 and run my xfstests, but at least one of the patches
won't apply... I also tried Linux 5.9-rc3 since that's what the
bdi-cleanups branch in git.infradead.org/users/hch/block.git
is based on, but that won't go either...

I guess the patches depend upon some of the other patches
in block.git/bdi-cleanups?

I got the 13 patches with git-format-patch on block.git
rather than scraping them out of my gmail, I think they're
the same?

Anywho... was just going to try and add a helpful(?)
data point...

-Mike

On Thu, Sep 24, 2020 at 2:53 AM Christoph Hellwig <hch@lst.de> wrote:
>
> Set up a readahead size by default, as very few users have a good
> reason to change it.  This means code, ecryptfs, and orangefs now
> set up the values while they were previously missing it, while ubifs,
> mtd and vboxsf manually set it to 0 to avoid readahead.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: Jan Kara <jack@suse.cz>
> Acked-by: David Sterba <dsterba@suse.com> [btrfs]
> Acked-by: Richard Weinberger <richard@nod.at> [ubifs, mtd]
> ---
>  block/blk-core.c      | 2 --
>  drivers/mtd/mtdcore.c | 2 ++
>  fs/9p/vfs_super.c     | 6 ++++--
>  fs/afs/super.c        | 1 -
>  fs/btrfs/disk-io.c    | 1 -
>  fs/fuse/inode.c       | 1 -
>  fs/nfs/super.c        | 9 +--------
>  fs/ubifs/super.c      | 2 ++
>  fs/vboxsf/super.c     | 2 ++
>  mm/backing-dev.c      | 2 ++
>  10 files changed, 13 insertions(+), 15 deletions(-)
>
> diff --git a/block/blk-core.c b/block/blk-core.c
> index ca3f0f00c9435f..865d39e5be2b28 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -538,8 +538,6 @@ struct request_queue *blk_alloc_queue(int node_id)
>         if (!q->stats)
>                 goto fail_stats;
>
> -       q->backing_dev_info->ra_pages = VM_READAHEAD_PAGES;
> -       q->backing_dev_info->io_pages = VM_READAHEAD_PAGES;
>         q->backing_dev_info->capabilities = BDI_CAP_CGROUP_WRITEBACK;
>         q->node = node_id;
>
> diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
> index 7d930569a7dfb7..b5e5d3140f578e 100644
> --- a/drivers/mtd/mtdcore.c
> +++ b/drivers/mtd/mtdcore.c
> @@ -2196,6 +2196,8 @@ static struct backing_dev_info * __init mtd_bdi_init(char *name)
>         bdi = bdi_alloc(NUMA_NO_NODE);
>         if (!bdi)
>                 return ERR_PTR(-ENOMEM);
> +       bdi->ra_pages = 0;
> +       bdi->io_pages = 0;
>
>         /*
>          * We put '-0' suffix to the name to get the same name format as we
> diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
> index 74df32be4c6a52..e34fa20acf612e 100644
> --- a/fs/9p/vfs_super.c
> +++ b/fs/9p/vfs_super.c
> @@ -80,8 +80,10 @@ v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
>         if (ret)
>                 return ret;
>
> -       if (v9ses->cache)
> -               sb->s_bdi->ra_pages = VM_READAHEAD_PAGES;
> +       if (!v9ses->cache) {
> +               sb->s_bdi->ra_pages = 0;
> +               sb->s_bdi->io_pages = 0;
> +       }
>
>         sb->s_flags |= SB_ACTIVE | SB_DIRSYNC;
>         if (!v9ses->cache)
> diff --git a/fs/afs/super.c b/fs/afs/super.c
> index b552357b1d1379..3a40ee752c1e3f 100644
> --- a/fs/afs/super.c
> +++ b/fs/afs/super.c
> @@ -456,7 +456,6 @@ static int afs_fill_super(struct super_block *sb, struct afs_fs_context *ctx)
>         ret = super_setup_bdi(sb);
>         if (ret)
>                 return ret;
> -       sb->s_bdi->ra_pages     = VM_READAHEAD_PAGES;
>
>         /* allocate the root inode and dentry */
>         if (as->dyn_root) {
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index f6bba7eb1fa171..047934cea25efa 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -3092,7 +3092,6 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
>         }
>
>         sb->s_bdi->capabilities |= BDI_CAP_CGROUP_WRITEBACK;
> -       sb->s_bdi->ra_pages = VM_READAHEAD_PAGES;
>         sb->s_bdi->ra_pages *= btrfs_super_num_devices(disk_super);
>         sb->s_bdi->ra_pages = max(sb->s_bdi->ra_pages, SZ_4M / PAGE_SIZE);
>
> diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
> index bba747520e9b08..17b00670fb539e 100644
> --- a/fs/fuse/inode.c
> +++ b/fs/fuse/inode.c
> @@ -1049,7 +1049,6 @@ static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
>         if (err)
>                 return err;
>
> -       sb->s_bdi->ra_pages = VM_READAHEAD_PAGES;
>         /* fuse does it's own writeback accounting */
>         sb->s_bdi->capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
>
> diff --git a/fs/nfs/super.c b/fs/nfs/super.c
> index 7a70287f21a2c1..f943e37853fa25 100644
> --- a/fs/nfs/super.c
> +++ b/fs/nfs/super.c
> @@ -1200,13 +1200,6 @@ static void nfs_get_cache_cookie(struct super_block *sb,
>  }
>  #endif
>
> -static void nfs_set_readahead(struct backing_dev_info *bdi,
> -                             unsigned long iomax_pages)
> -{
> -       bdi->ra_pages = VM_READAHEAD_PAGES;
> -       bdi->io_pages = iomax_pages;
> -}
> -
>  int nfs_get_tree_common(struct fs_context *fc)
>  {
>         struct nfs_fs_context *ctx = nfs_fc2context(fc);
> @@ -1251,7 +1244,7 @@ int nfs_get_tree_common(struct fs_context *fc)
>                                              MINOR(server->s_dev));
>                 if (error)
>                         goto error_splat_super;
> -               nfs_set_readahead(s->s_bdi, server->rpages);
> +               s->s_bdi->io_pages = server->rpages;
>                 server->super = s;
>         }
>
> diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
> index a2420c900275a8..fbddb2a1c03f5e 100644
> --- a/fs/ubifs/super.c
> +++ b/fs/ubifs/super.c
> @@ -2177,6 +2177,8 @@ static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
>                                    c->vi.vol_id);
>         if (err)
>                 goto out_close;
> +       sb->s_bdi->ra_pages = 0;
> +       sb->s_bdi->io_pages = 0;
>
>         sb->s_fs_info = c;
>         sb->s_magic = UBIFS_SUPER_MAGIC;
> diff --git a/fs/vboxsf/super.c b/fs/vboxsf/super.c
> index 8fe03b4a0d2b03..8e3792177a8523 100644
> --- a/fs/vboxsf/super.c
> +++ b/fs/vboxsf/super.c
> @@ -167,6 +167,8 @@ static int vboxsf_fill_super(struct super_block *sb, struct fs_context *fc)
>         err = super_setup_bdi_name(sb, "vboxsf-%d", sbi->bdi_id);
>         if (err)
>                 goto fail_free;
> +       sb->s_bdi->ra_pages = 0;
> +       sb->s_bdi->io_pages = 0;
>
>         /* Turn source into a shfl_string and map the folder */
>         size = strlen(fc->source) + 1;
> diff --git a/mm/backing-dev.c b/mm/backing-dev.c
> index 8e8b00627bb2d8..2dac3be6127127 100644
> --- a/mm/backing-dev.c
> +++ b/mm/backing-dev.c
> @@ -746,6 +746,8 @@ struct backing_dev_info *bdi_alloc(int node_id)
>                 kfree(bdi);
>                 return NULL;
>         }
> +       bdi->ra_pages = VM_READAHEAD_PAGES;
> +       bdi->io_pages = VM_READAHEAD_PAGES;
>         return bdi;
>  }
>  EXPORT_SYMBOL(bdi_alloc);
> --
> 2.28.0
>