Re: [PATCH 5/5] zfs extensible_dataset and large_blocks feature support

[Andrei Borzenkov]

В Thu, 16 Apr 2015 08:24:38 +0300
Toomas Soome <address@hidden> пишет:

> 

Could you explain how these changes affect large block read? As far as
I understand, this feature is basically "for free" - changes were
needed to allow large block writes, but on disk format already
supported them so reading should have just worked?

> ---
>  grub-core/fs/zfs/zfs.c |   18 +++++++++++-------
>  1 file changed, 11 insertions(+), 7 deletions(-)
> 
> diff --git a/grub-core/fs/zfs/zfs.c b/grub-core/fs/zfs/zfs.c
> index da44131..4a542e0 100644
> --- a/grub-core/fs/zfs/zfs.c
> +++ b/grub-core/fs/zfs/zfs.c
> @@ -283,6 +283,8 @@ static const char *spa_feature_names[] = {
>    "org.illumos:lz4_compress",
>    "com.delphix:hole_birth",
>    "com.delphix:embedded_data",
> +  "com.delphix:extensible_dataset",
> +  "org.open-zfs:large_blocks",
>    NULL
>  };
>  
> @@ -3080,7 +3082,7 @@ get_filesystem_dnode (dnode_end_t * mosmdn, char 
> *fsname,
>  
>    grub_dprintf ("zfs", "alive\n");
>  
> -  err = dnode_get (mosmdn, objnum, DMU_OT_DSL_DIR, mdn, data);
> +  err = dnode_get (mosmdn, objnum, 0, mdn, data);
>    if (err)
>      return err;
>  
> @@ -3113,7 +3115,7 @@ get_filesystem_dnode (dnode_end_t * mosmdn, char 
> *fsname,
>        if (err)
>       return err;
>  
> -      err = dnode_get (mosmdn, objnum, DMU_OT_DSL_DIR, mdn, data);
> +      err = dnode_get (mosmdn, objnum, 0, mdn, data);
>        if (err)
>       return err;
>  
> @@ -3268,8 +3270,7 @@ dnode_get_fullpath (const char *fullpath, struct 
> subvolume *subvol,
>  
>    grub_dprintf ("zfs", "endian = %d\n", subvol->mdn.endian);
>  
> -  err = dnode_get (&(data->mos), headobj, DMU_OT_DSL_DATASET, &subvol->mdn,
> -                data);
> +  err = dnode_get (&(data->mos), headobj, 0, &subvol->mdn, data);
>    if (err)
>      {
>        grub_free (fsname);
> @@ -3665,8 +3666,11 @@ zfs_mount (grub_device_t dev)
>    if (ub->ub_version >= SPA_VERSION_FEATURES &&
>        check_mos_features(&((objset_phys_t *) osp)->os_meta_dnode,ub_endian,
>                        data) != 0)
> -    return NULL;
> -     
> +    {
> +      grub_error (GRUB_ERR_BAD_FS, "Unsupported features in pool");
> +      return NULL;
> +    }
> +
>    /* Got the MOS. Save it at the memory addr MOS. */
>    grub_memmove (&(data->mos.dn), &((objset_phys_t *) osp)->os_meta_dnode,
>               DNODE_SIZE);
> @@ -3963,7 +3967,7 @@ fill_fs_info (struct grub_dirhook_info *info,
>      {
>        headobj = grub_zfs_to_cpu64 (((dsl_dir_phys_t *) DN_BONUS 
> (&mdn.dn))->dd_head_dataset_obj, mdn.endian);
>  
> -      err = dnode_get (&(data->mos), headobj, DMU_OT_DSL_DATASET, &mdn, 
> data);
> +      err = dnode_get (&(data->mos), headobj, 0, &mdn, data);
>        if (err)
>       {
>         grub_dprintf ("zfs", "failed here\n");