Re: [Qemu-devel] [PATCH 1/2] raw-posix: Fix raw_co_get_block_status() after EOF

["Benoît Canet" <benoit.canet@irqsave.net>]

The Monday 22 Sep 2014 à 17:23:44 (+0200), Max Reitz wrote :
> As its comment states, raw_co_get_block_status() should unconditionally
> return 0 and set *pnum to 0 for after EOF.
> 
> An assertion after lseek(..., SEEK_HOLE) tried to catch this case by
> asserting that errno != -ENXIO (which would indicate a position after
> the EOF); but it should be errno != ENXIO instead. Fix this, too.
> 
> Reported-by: Kevin Wolf <kwolf@redhat.com>
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>  block/raw-posix.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/block/raw-posix.c b/block/raw-posix.c
> index a253697..de4e3f3 100644
> --- a/block/raw-posix.c
> +++ b/block/raw-posix.c
> @@ -1509,9 +1509,9 @@ static int64_t try_seek_hole(BlockDriverState *bs, off_t start, off_t *data,
>  
>      *hole = lseek(s->fd, start, SEEK_HOLE);
>      if (*hole == -1) {
> -        /* -ENXIO indicates that sector_num was past the end of the file.
> +        /* ENXIO indicates that sector_num was past the end of the file.
>           * There is a virtual hole there.  */
> -        assert(errno != -ENXIO);
> +        assert(errno != ENXIO);
>  
>          return -errno;
>      }
> @@ -1560,6 +1560,10 @@ static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs,
>      }
>  
>      start = sector_num * BDRV_SECTOR_SIZE;
> +    if (start >= bdrv_getlength(bs)) {
> +        *pnum = 0;
> +        return 0;
> +    }
>  
>      ret = try_fiemap(bs, start, &data, &hole, nb_sectors, pnum);
>      if (ret < 0) {
> -- 
> 2.1.0
> 
> 
Reviewed-by: Benoît Canet <benoit.canet@nodalink.com>