[PATCH] hostfs: Fix writeback of dirty pages

[Ritesh Raj Sarraf]

On Fri, 2021-11-05 at 09:10 +0100, Sjoerd Simons wrote:
> Hostfs was not setting up the backing device information, which means
> it
> uses the noop bdi. The noop bdi does not have the writeback
> capability
> enabled, which in turns means  dirty pages never got written back to
> storage.
> 
> In other words programs using mmap to write to files on  hostfs never
> actually got their data written out...
> 
> Fix this by simply setting up the bdi with default settings as all
> the
> required code for writeback is already in place.
> 
> Signed-off-by: Sjoerd Simons <sjoerd at collabora.com>
> 

Tested-by: Ritesh Raj Sarraf <ritesh at collabora.com>

> ---
> 
>  fs/hostfs/hostfs_kern.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
> index d5c9d886cd9f..ef481c3d9019 100644
> --- a/fs/hostfs/hostfs_kern.c
> +++ b/fs/hostfs/hostfs_kern.c
> @@ -924,6 +924,9 @@ static int hostfs_fill_sb_common(struct
> super_block *sb, void *d, int silent)
>         sb->s_op = &hostfs_sbops;
>         sb->s_d_op = &simple_dentry_operations;
>         sb->s_maxbytes = MAX_LFS_FILESIZE;
> +       err = super_setup_bdi(sb);
> +       if (err)
> +               goto out;
>  
>         /* NULL is printed as '(null)' by printf(): avoid that. */
>         if (req_root == NULL)

-- 
Ritesh Raj Sarraf
Collabora
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