[12/22] 9pfs: use V9fsBlob to transmit xattr

And make v9fs_pack static function. Now we only need to export
v9fs_{,un}marshal to device.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 fsdev/virtio-9p-marshal.c |  4 ++--
 fsdev/virtio-9p-marshal.h |  3 ---
 hw/9pfs/virtio-9p.c       | 21 +++++++++++++--------
 3 files changed, 15 insertions(+), 13 deletions(-)

Wei Liu <wei.liu2@citrix.com> writes:

> And make v9fs_pack static function. Now we only need to export
> v9fs_{,un}marshal to device.


Any advantage of doing this ? compared to v9fs_pack ?. Trying to
understand if i am missing something here 

>
> Signed-off-by: Wei Liu <wei.liu2@citrix.com>
> ---
>  fsdev/virtio-9p-marshal.c |  4 ++--
>  fsdev/virtio-9p-marshal.h |  3 ---
>  hw/9pfs/virtio-9p.c       | 21 +++++++++++++--------
>  3 files changed, 15 insertions(+), 13 deletions(-)
>
> diff --git a/fsdev/virtio-9p-marshal.c b/fsdev/virtio-9p-marshal.c
> index c3ac316..d120bd2 100644
> --- a/fsdev/virtio-9p-marshal.c
> +++ b/fsdev/virtio-9p-marshal.c
> @@ -70,8 +70,8 @@ static ssize_t v9fs_unpack(void *dst, struct iovec *out_sg, int out_num,
>      return v9fs_packunpack(dst, out_sg, out_num, offset, size, 0);
>  }
>
> -ssize_t v9fs_pack(struct iovec *in_sg, int in_num, size_t offset,
> -                  const void *src, size_t size)
> +static ssize_t v9fs_pack(struct iovec *in_sg, int in_num, size_t offset,
> +                         const void *src, size_t size)
>  {
>      return v9fs_packunpack((void *)src, in_sg, in_num, offset, size, 1);
>  }
> diff --git a/fsdev/virtio-9p-marshal.h b/fsdev/virtio-9p-marshal.h
> index 0709bcd..766a48e 100644
> --- a/fsdev/virtio-9p-marshal.h
> +++ b/fsdev/virtio-9p-marshal.h
> @@ -3,9 +3,6 @@
>
>  #include "9p-marshal.h"
>
> -
> -ssize_t v9fs_pack(struct iovec *in_sg, int in_num, size_t offset,
> -                  const void *src, size_t size);
>  ssize_t v9fs_unmarshal(struct iovec *out_sg, int out_num, size_t offset,
>                         int bswap, const char *fmt, ...);
>  ssize_t v9fs_marshal(struct iovec *in_sg, int in_num, size_t offset,
> diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
> index 084fa6a..5da25ec 100644
> --- a/hw/9pfs/virtio-9p.c
> +++ b/hw/9pfs/virtio-9p.c
> @@ -1561,6 +1561,7 @@ static int v9fs_xattr_read(V9fsState *s, V9fsPDU *pdu, V9fsFidState *fidp,
>      size_t offset = 7;
>      int read_count;
>      int64_t xattr_len;
> +    V9fsBlob blob;
>
>      xattr_len = fidp->fs.xattr.len;
>      read_count = xattr_len - off;
> @@ -1572,14 +1573,18 @@ static int v9fs_xattr_read(V9fsState *s, V9fsPDU *pdu, V9fsFidState *fidp,
>           */
>          read_count = 0;
>      }
> -    err = pdu_marshal(pdu, offset, "d", read_count);
> -    if (err < 0) {
> -        return err;
> -    }
> -    offset += err;
> -    err = v9fs_pack(pdu->elem.in_sg, pdu->elem.in_num, offset,
> -                    ((char *)fidp->fs.xattr.value) + off,
> -                    read_count);
> +
> +    v9fs_blob_init(&blob);
> +
> +    blob.data = g_malloc(read_count);
> +    memcpy(blob.data, ((char *)fidp->fs.xattr.value) + off,
> +           read_count);
> +    blob.size = read_count;
> +
> +    err = pdu_marshal(pdu, offset, "dB", read_count, &blob);
> +
> +    v9fs_blob_free(&blob);
> +
>      if (err < 0) {
>          return err;
>      }
> -- 
> 2.1.4

On Thu, Jan 07, 2016 at 10:19:47PM +0530, Aneesh Kumar K.V wrote:
> Wei Liu <wei.liu2@citrix.com> writes:
> 
> > And make v9fs_pack static function. Now we only need to export
> > v9fs_{,un}marshal to device.
> 
> 
> Any advantage of doing this ? compared to v9fs_pack ?. Trying to
> understand if i am missing something here 
> 

The reason for exporting v9fs_pack is because there is no abstraction of
blob in marshalling interface. We should fix marshalling functions
instead of leaking v9fs_pack to device.

As said in the commit message, with this change now we only need to
export v9fs_marshal and v9fs_unmarshal to device. That's a much cleaner
interface.

Wei.