[CRIU] [PATCH 1/2] mount: fill fstypes for btrfs mounts on restore

[Pavel Emelyanov]

On 04/17/2014 03:04 PM, Andrew Vagin wrote:
> BTRFS returns subvolume dev-id instead of superblock dev-id,
> so we need to know which mounts are btrfs.
> 
> Signed-off-by: Andrew Vagin <avagin at openvz.org>
> ---
>  include/fs-magic.h |  4 ++++
>  mount.c            | 13 +++++++++++++
>  2 files changed, 17 insertions(+)
> 
> diff --git a/include/fs-magic.h b/include/fs-magic.h
> index 9db3ee9..12bb982 100644
> --- a/include/fs-magic.h
> +++ b/include/fs-magic.h
> @@ -33,4 +33,8 @@
>  #define DEVPTS_SUPER_MAGIC	0x1cd1
>  #endif
>  
> +#ifndef BTRFS_SUPER_MAGIC
> +#define BTRFS_SUPER_MAGIC	0x9123683E
> +#endif
> +
>  #endif /* __CR_FS_MAGIC_H__ */
> diff --git a/mount.c b/mount.c
> index 043b2c3..cddaf7f 100644
> --- a/mount.c
> +++ b/mount.c
> @@ -25,6 +25,8 @@
>  #include "namespaces.h"
>  #include "protobuf.h"
>  #include "kerndat.h"
> +#include "fs-magic.h"
> +
>  #include "protobuf/mnt.pb-c.h"
>  
>  /*
> @@ -1230,6 +1232,17 @@ static int do_mount_one(struct mount_info *mi)
>  	if (ret == 0 && propagate_mount(mi))
>  		return -1;
>  
> +	if (mi->fstype->code == FSTYPE__UNSUPPORTED) {
> +		struct statfs st;
> +
> +		if (statfs(mi->mountpoint, &st)) {
> +			pr_perror("Unable to statfs %s", mi->mountpoint);
> +			return -1;
> +		}
> +		if (st.f_type == BTRFS_SUPER_MAGIC)
> +			mi->fstype = find_fstype_by_name("btrfs");

mi->fstype = find_fstype_by_name(mi->fstype->name)?

> +	}
> +
>  	return ret;
>  }
>  
>