Re: [Qemu-devel] [PATCH v7 11/35] util: introduce qemu_file_getlength()

[Eduardo Habkost]

As this patch affects raw_getlength(), CCing the raw block driver
maintainer and the qemu-block mailing list.

On Mon, Nov 02, 2015 at 05:13:13PM +0800, Xiao Guangrong wrote:
> It is used to get the size of the specified file, also qemu_fd_getlength()
> is introduced to unify the code with raw_getlength() in block/raw-posix.c
> 
> Signed-off-by: Xiao Guangrong <address@hidden>
> ---
>  block/raw-posix.c    |  7 +------
>  include/qemu/osdep.h |  2 ++
>  util/osdep.c         | 31 +++++++++++++++++++++++++++++++

I know I was the one who suggested osdep.c, but maybe oslib-posix.c is a
more appropriate place for the new function?


>  3 files changed, 34 insertions(+), 6 deletions(-)
> 
> diff --git a/block/raw-posix.c b/block/raw-posix.c
> index 918c756..734e6dd 100644
> --- a/block/raw-posix.c
> +++ b/block/raw-posix.c
> @@ -1592,18 +1592,13 @@ static int64_t raw_getlength(BlockDriverState *bs)
>  {
>      BDRVRawState *s = bs->opaque;
>      int ret;
> -    int64_t size;
>  
>      ret = fd_open(bs);
>      if (ret < 0) {
>          return ret;
>      }
>  
> -    size = lseek(s->fd, 0, SEEK_END);
> -    if (size < 0) {
> -        return -errno;
> -    }
> -    return size;
> +    return qemu_fd_getlength(s->fd);
>  }
>  #endif
>  
> diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
> index dbc17dc..ca4c3fa 100644
> --- a/include/qemu/osdep.h
> +++ b/include/qemu/osdep.h
> @@ -303,4 +303,6 @@ int qemu_read_password(char *buf, int buf_size);
>  pid_t qemu_fork(Error **errp);
>  
>  size_t qemu_file_get_page_size(const char *mem_path, Error **errp);
> +int64_t qemu_fd_getlength(int fd);
> +size_t qemu_file_getlength(const char *file, Error **errp);
>  #endif
> diff --git a/util/osdep.c b/util/osdep.c
> index 0092bb6..5a61e19 100644
> --- a/util/osdep.c
> +++ b/util/osdep.c
> @@ -428,3 +428,34 @@ writev(int fd, const struct iovec *iov, int iov_cnt)
>      return readv_writev(fd, iov, iov_cnt, true);
>  }
>  #endif
> +
> +int64_t qemu_fd_getlength(int fd)
> +{
> +    int64_t size;
> +
> +    size = lseek(fd, 0, SEEK_END);
> +    if (size < 0) {
> +        return -errno;
> +    }
> +    return size;
> +}
> +
> +size_t qemu_file_getlength(const char *file, Error **errp)
> +{
> +    int64_t size;
> +    int fd = qemu_open(file, O_RDONLY);
> +
> +    if (fd < 0) {
> +        error_setg_file_open(errp, errno, file);
> +        return 0;
> +    }
> +
> +    size = qemu_fd_getlength(fd);
> +    if (size < 0) {
> +        error_setg_errno(errp, -size, "can't get size of file %s", file);
> +        size = 0;
> +    }
> +
> +    qemu_close(fd);
> +    return size;
> +}
> -- 
> 1.8.3.1
> 

-- 
Eduardo