Re: [PATCH] virtiofsd: Disable remote posix locks by default

[Dr. David Alan Gilbert]

* Vivek Goyal (vgoyal@redhat.com) wrote:
> Right now we enable remote posix locks by default. That means when guest
> does a posix lock it sends request to server (virtiofsd). But currently
> we only support non-blocking posix lock and return -EOPNOTSUPP for
> blocking version.
> 
> This means that existing applications which are doing blocking posix
> locks get -EOPNOTSUPP and fail. To avoid this, people have been
> running virtiosd with option "-o no_posix_lock". For new users it
> is still a surprise and trial and error takes them to this option.
> 
> Given posix lock implementation is not complete in virtiofsd, disable
> it by default. This means that posix locks will work with-in applications
> in a guest but not across guests. Anyway we don't support sharing
> filesystem among different guests yet in virtiofs so this should
> not lead to any kind of surprise or regression and will make life
> little easier for virtiofs users.
> 
> Reported-by: Aa Aa <jimbothom@yandex.com>
> Suggested-by: Miklos Szeredi <mszeredi@redhat.com>
> Signed-off-by: Vivek Goyal <vgoyal@redhat.com>

Thanks, queued into my local dev world; I'll push it out after some
others and get it into the qemu world when it reopens.

Dave
> ---
>  tools/virtiofsd/passthrough_ll.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/virtiofsd/passthrough_ll.c 
> b/tools/virtiofsd/passthrough_ll.c
> index 6514674f04..82d8c962d0 100644
> --- a/tools/virtiofsd/passthrough_ll.c
> +++ b/tools/virtiofsd/passthrough_ll.c
> @@ -3208,7 +3208,7 @@ int main(int argc, char *argv[])
>      struct lo_data lo = {
>          .debug = 0,
>          .writeback = 0,
> -        .posix_lock = 1,
> +        .posix_lock = 0,
>          .proc_self_fd = -1,
>      };
>      struct lo_map_elem *root_elem;
> -- 
> 2.25.4
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK