[sheepdog] [PATCH] sheepfs: fix volume read/write operation

[Robin Dong]

Reviewed-by: Robin Dong <sanbai at taobao.com>


2014/1/9 Liu Yuan <namei.unix at gmail.com>

> We should return how many bytes actually written/read from vdi. This fixes
> a
> bug that cat sheepfs/volume/vdi never return.
>
> Signed-off-by: Liu Yuan <namei.unix at gmail.com>
> ---
>  sheepfs/volume.c | 32 ++++++++++++++++++++++++--------
>  1 file changed, 24 insertions(+), 8 deletions(-)
>
> diff --git a/sheepfs/volume.c b/sheepfs/volume.c
> index f6aadaf..f862c4a 100644
> --- a/sheepfs/volume.c
> +++ b/sheepfs/volume.c
> @@ -207,18 +207,29 @@ done:
>  }
>
>  /* Do sync read/write */
> -static int volume_do_rw(const char *path, char *buf, size_t size,
> -                        off_t offset, int rw)
> +static ssize_t volume_do_rw(const char *path, char *buf, size_t size,
> +                           off_t offset, int rw)
>  {
>         uint32_t vid;
>         uint64_t oid;
>         unsigned long idx;
>         off_t start;
> -       size_t len, ret;
> +       size_t len, ret, vdi_size, sz;
>
>         if (shadow_file_getxattr(path, SH_VID_NAME, &vid, SH_VID_SIZE) < 0)
>                 return -1;
>
> +       if (shadow_file_getxattr(path, SH_SIZE_NAME, &vdi_size,
> SH_SIZE_SIZE)
> +           < 0)
> +               return -1;
> +
> +       if (offset >= vdi_size)
> +               return 0;
> +
> +       if (offset + size > vdi_size)
> +               size = vdi_size - offset;
> +
> +       sz = size;
>         idx = offset / SD_DATA_OBJ_SIZE;
>         oid = vid_to_data_oid(vid, idx);
>         start = offset % SD_DATA_OBJ_SIZE;
> @@ -246,7 +257,7 @@ static int volume_do_rw(const char *path, char *buf,
> size_t size,
>                 len = size > SD_DATA_OBJ_SIZE ? SD_DATA_OBJ_SIZE : size;
>         } while (size > 0);
>
> -       return 0;
> +       return sz - size;
>  }
>
>  int sheepfs_bnode_writer(uint64_t oid, void *mem, unsigned int len,
> @@ -272,19 +283,24 @@ int sheepfs_bnode_reader(uint64_t oid, void **mem,
> unsigned int len,
>
>  int volume_read(const char *path, char *buf, size_t size, off_t offset)
>  {
> +       ssize_t done;
>
> -       if (volume_do_rw(path, buf, size, offset, VOLUME_READ) < 0)
> +       done = volume_do_rw(path, buf, size, offset, VOLUME_READ);
> +       if (done < 0)
>                 return -EIO;
>
> -       return size;
> +       return done;
>  }
>
>  int volume_write(const char *path, const char *buf, size_t size, off_t
> offset)
>  {
> -       if (volume_do_rw(path, (char *)buf, size, offset, VOLUME_WRITE) <
> 0)
> +       ssize_t done;
> +
> +       done = volume_do_rw(path, (char *)buf, size, offset, VOLUME_WRITE);
> +       if (done < 0)
>                 return -EIO;
>
> -       return size;
> +       return done;
>  }
>
>  size_t volume_get_size(const char *path)
> --
> 1.8.1.2
>
> --
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> sheepdog at lists.wpkg.org
> http://lists.wpkg.org/mailman/listinfo/sheepdog
>



-- 
--
Best Regard
Robin Dong
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