Re: [PATCH 1/2] libfuse: don't use SYNC_INIT unless asked for

[Bernd Schubert <bernd@bsbernd.com>]

On 5/5/26 07:23, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@kernel.org>
> 
> If we didn't ask for SYNC_INIT, don't enable it.  This is needed to
> maintain compatibility with older fuse servers that only support
> asynchronous FUSE_INIT.
> 
> Fixes: 3e1101057aea57 ("fuse mount: Support synchronous FUSE_INIT (privileged daemon)")
> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> ---
>  lib/fuse_lowlevel.c |    6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> 
> diff --git a/lib/fuse_lowlevel.c b/lib/fuse_lowlevel.c
> index 0e16845d2f14ff..0a801132590079 100644
> --- a/lib/fuse_lowlevel.c
> +++ b/lib/fuse_lowlevel.c
> @@ -4475,9 +4475,9 @@ static int session_start_sync_init(struct fuse_session *se, int fd)
>  {
>  	int err, res;
>  
> -	if (!se->want_sync_init &&
> -		(se->uring.enable && !fuse_daemonize_is_used())) {
> -		if (se->debug)
> +	if (!se->want_sync_init) {
> +		/* SYNC_INIT is required for io_uring(?) */
> +		if ((se->uring.enable && !fuse_daemonize_is_used()) || se->debug)
>  			fuse_log(FUSE_LOG_DEBUG,
>  					"fuse: sync init not enabled\n");
>  		return 0;
> 

Hmm, but mounting is kind of a libuse internal part? If this is really
needed the commit message should mention the exact reason - what is the
issue with old fuse servers and sync init?


Thanks,
Bernd