[Virtio-fs] [PATCH 4/4] virtiofsd: use fallocate(2) instead posix_fallocate(3)

[Dr. David Alan Gilbert]

* Liu Bo (bo.liu at linux.alibaba.com) wrote:
> From: Xiaoguang Wang <xiaoguang.wang at linux.alibaba.com>
> 
> This is because posix_fallocate(3) does not support FALLOC_FL_KEEP_SIZE
> and FALLOC_FL_PUNCH_HOLE. Our underlying host filesystem is ext4 and
> ext4 supports FALLOC_FL_KEEP_SIZE and FALLOC_FL_PUNCH_HOLE well, so
> this change will be ok.
> 
> Signed-off-by: Xiaoguang Wang <xiaoguang.wang at linux.alibaba.com>

  We need to check what 'fuse' expects - is it defined what
fallocate features it has, and what the semantics are?

Miklos: Do you know?

Dave

  
> ---
>  contrib/virtiofsd/passthrough_ll.c | 11 +++--------
>  1 file changed, 3 insertions(+), 8 deletions(-)
> 
> diff --git a/contrib/virtiofsd/passthrough_ll.c b/contrib/virtiofsd/passthrough_ll.c
> index 10ea8aa..ccb5312 100644
> --- a/contrib/virtiofsd/passthrough_ll.c
> +++ b/contrib/virtiofsd/passthrough_ll.c
> @@ -1568,15 +1568,10 @@ static void lo_fallocate(fuse_req_t req, fuse_ino_t ino, int mode,
>  			 off_t offset, off_t length, struct fuse_file_info *fi)
>  {
>  	int err;
> -	(void) ino;
> -
> -	if (mode) {
> -		fuse_reply_err(req, EOPNOTSUPP);
> -		return;
> -	}
>  
> -	err = posix_fallocate(lo_fi_fd(req, fi), offset,
> -			      length);
> +	err = fallocate(lo_fi_fd(req, fi), mode, offset, length);
> +        if (err < 0)
> +                err = errno;
>  
>  	fuse_reply_err(req, err);
>  }
> -- 
> 1.8.3.1
> 
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--
Dr. David Alan Gilbert / dgilbert at redhat.com / Manchester, UK