Re: [PATCH 2/2] gssd: don't let parent exit until child has a chance to scan directory once

["J. Bruce Fields" <bfields@fieldses.org>]

On Fri, Nov 15, 2013 at 02:15:31PM -0500, Jeff Layton wrote:
> With some proposed kernel changes, it won't even attempt to upcall
> sometimes if it doesn't appear that gssd is running. This means that
> we have a theoretical race between gssd starting up at boot time and
> the init process attempting to mount kerberized filesystems.
> 
> Fix this by switching gssd to use mydaemon() and having the child
> only release the parent after it has processed the directory once.

Makes sense to me, thanks--ACK.

--b.

> 
> Signed-off-by: Jeff Layton <jlayton@redhat.com>
> ---
>  utils/gssd/gssd.c           | 6 ++++--
>  utils/gssd/gssd.h           | 1 +
>  utils/gssd/gssd_main_loop.c | 4 ++++
>  3 files changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/utils/gssd/gssd.c b/utils/gssd/gssd.c
> index 8ee478b..fdad153 100644
> --- a/utils/gssd/gssd.c
> +++ b/utils/gssd/gssd.c
> @@ -54,6 +54,7 @@
>  #include "err_util.h"
>  #include "gss_util.h"
>  #include "krb5_util.h"
> +#include "nfslib.h"
>  
>  char pipefs_dir[PATH_MAX] = GSSD_PIPEFS_DIR;
>  char keytabfile[PATH_MAX] = GSSD_DEFAULT_KEYTAB_FILE;
> @@ -63,6 +64,7 @@ int  use_memcache = 0;
>  int  root_uses_machine_creds = 1;
>  unsigned int  context_timeout = 0;
>  char *preferred_realm = NULL;
> +int pipefds[2] = { -1, -1 };
>  
>  void
>  sig_die(int signal)
> @@ -187,8 +189,8 @@ main(int argc, char *argv[])
>  	if (gssd_check_mechs() != 0)
>  		errx(1, "Problem with gssapi library");
>  
> -	if (!fg && daemon(0, 0) < 0)
> -		errx(1, "fork");
> +	if (!fg)
> +		mydaemon(0, 0, pipefds);
>  
>  	signal(SIGINT, sig_die);
>  	signal(SIGTERM, sig_die);
> diff --git a/utils/gssd/gssd.h b/utils/gssd/gssd.h
> index 86472a1..47995b7 100644
> --- a/utils/gssd/gssd.h
> +++ b/utils/gssd/gssd.h
> @@ -67,6 +67,7 @@ extern int			use_memcache;
>  extern int			root_uses_machine_creds;
>  extern unsigned int 		context_timeout;
>  extern char			*preferred_realm;
> +extern int			pipefds[2];
>  
>  TAILQ_HEAD(clnt_list_head, clnt_info) clnt_list;
>  
> diff --git a/utils/gssd/gssd_main_loop.c b/utils/gssd/gssd_main_loop.c
> index ccf7fe5..9970028 100644
> --- a/utils/gssd/gssd_main_loop.c
> +++ b/utils/gssd/gssd_main_loop.c
> @@ -53,6 +53,7 @@
>  
>  #include "gssd.h"
>  #include "err_util.h"
> +#include "nfslib.h"
>  
>  extern struct pollfd *pollarray;
>  extern unsigned long pollsize;
> @@ -245,6 +246,9 @@ gssd_run()
>  				/* Error msg is already printed */
>  				exit(1);
>  			}
> +
> +			/* release the parent after the initial dir scan */
> +			release_parent(pipefds);
>  		}
>  		gssd_poll(pollarray, pollsize);
>  	}
> -- 
> 1.8.3.1
> 
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