[dm-devel] [PATCH v2 12/48] multipathd: add and set cli_handlers in a single step

[Benjamin Marzinski]

On Thu, Nov 18, 2021 at 11:58:04PM +0100, mwilck at suse.com wrote:
> From: Martin Wilck <mwilck at suse.com>
> 
> Modify set_handler_callback() such that a missing slot is created
> if no matching slot is found. This way, we can skip the initialization
> with NULL handlers on startup. Assigning the same handler multiple
> times would be a bug which is tested with assert().
> 
> Signed-off-by: Martin Wilck <mwilck at suse.com>
Reviewed-by: Benjamin Marzinski <bmarzins at redhat.com>
> ---
>  multipathd/cli.c | 95 ++++++++----------------------------------------
>  multipathd/cli.h |  7 ++--
>  2 files changed, 19 insertions(+), 83 deletions(-)
> 
> diff --git a/multipathd/cli.c b/multipathd/cli.c
> index 5213813..6e5056e 100644
> --- a/multipathd/cli.c
> +++ b/multipathd/cli.c
> @@ -4,6 +4,7 @@
>  #include <sys/time.h>
>  #include <errno.h>
>  #include <pthread.h>
> +#include <assert.h>
>  #include "memory.h"
>  #include "vector.h"
>  #include "structs.h"
> @@ -64,26 +65,26 @@ out:
>  	return 1;
>  }
>  
> -int
> -add_handler (uint64_t fp, cli_handler *fn)
> +static struct handler *add_handler(uint64_t fp, cli_handler *fn, bool locked)
>  {
>  	struct handler * h;
>  
>  	h = alloc_handler();
>  
> -	if (!h)
> -		return 1;
> +	if (h == NULL)
> +		return NULL;
>  
>  	if (!vector_alloc_slot(handlers)) {
>  		FREE(h);
> -		return 1;
> +		return NULL;
>  	}
>  
>  	vector_set_slot(handlers, h);
>  	h->fingerprint = fp;
>  	h->fn = fn;
> +	h->locked = locked;
>  
> -	return 0;
> +	return h;
>  }
>  
>  static struct handler *
> @@ -100,26 +101,17 @@ find_handler (uint64_t fp)
>  }
>  
>  int
> -set_handler_callback (uint64_t fp, cli_handler *fn)
> +__set_handler_callback (uint64_t fp, cli_handler *fn, bool locked)
>  {
> -	struct handler * h = find_handler(fp);
> +	struct handler *h;
>  
> -	if (!h)
> +	assert(find_handler(fp) == NULL);
> +        h = add_handler(fp, fn, locked);
> +        if (!h) {
> +		condlog(0, "%s: failed to set handler for code %"PRIu64,
> +			__func__, fp);
>  		return 1;
> -	h->fn = fn;
> -	h->locked = 1;
> -	return 0;
> -}
> -
> -int
> -set_unlocked_handler_callback (uint64_t fp, cli_handler *fn)
> -{
> -	struct handler * h = find_handler(fp);
> -
> -	if (!h)
> -		return 1;
> -	h->fn = fn;
> -	h->locked = 0;
> +	}
>  	return 0;
>  }
>  
> @@ -513,63 +505,6 @@ cli_init (void) {
>  	if (alloc_handlers())
>  		return 1;
>  
> -	add_handler(LIST+PATHS, NULL);
> -	add_handler(LIST+PATHS+FMT, NULL);
> -	add_handler(LIST+PATHS+RAW+FMT, NULL);
> -	add_handler(LIST+PATH, NULL);
> -	add_handler(LIST+STATUS, NULL);
> -	add_handler(LIST+DAEMON, NULL);
> -	add_handler(LIST+MAPS, NULL);
> -	add_handler(LIST+MAPS+STATUS, NULL);
> -	add_handler(LIST+MAPS+STATS, NULL);
> -	add_handler(LIST+MAPS+FMT, NULL);
> -	add_handler(LIST+MAPS+RAW+FMT, NULL);
> -	add_handler(LIST+MAPS+TOPOLOGY, NULL);
> -	add_handler(LIST+MAPS+JSON, NULL);
> -	add_handler(LIST+TOPOLOGY, NULL);
> -	add_handler(LIST+MAP+TOPOLOGY, NULL);
> -	add_handler(LIST+MAP+JSON, NULL);
> -	add_handler(LIST+MAP+FMT, NULL);
> -	add_handler(LIST+MAP+RAW+FMT, NULL);
> -	add_handler(LIST+CONFIG, NULL);
> -	add_handler(LIST+CONFIG+LOCAL, NULL);
> -	add_handler(LIST+BLACKLIST, NULL);
> -	add_handler(LIST+DEVICES, NULL);
> -	add_handler(LIST+WILDCARDS, NULL);
> -	add_handler(RESET+MAPS+STATS, NULL);
> -	add_handler(RESET+MAP+STATS, NULL);
> -	add_handler(ADD+PATH, NULL);
> -	add_handler(DEL+PATH, NULL);
> -	add_handler(ADD+MAP, NULL);
> -	add_handler(DEL+MAP, NULL);
> -	add_handler(DEL+MAPS, NULL);
> -	add_handler(SWITCH+MAP+GROUP, NULL);
> -	add_handler(RECONFIGURE, NULL);
> -	add_handler(SUSPEND+MAP, NULL);
> -	add_handler(RESUME+MAP, NULL);
> -	add_handler(RESIZE+MAP, NULL);
> -	add_handler(RESET+MAP, NULL);
> -	add_handler(RELOAD+MAP, NULL);
> -	add_handler(DISABLEQ+MAP, NULL);
> -	add_handler(RESTOREQ+MAP, NULL);
> -	add_handler(DISABLEQ+MAPS, NULL);
> -	add_handler(RESTOREQ+MAPS, NULL);
> -	add_handler(REINSTATE+PATH, NULL);
> -	add_handler(FAIL+PATH, NULL);
> -	add_handler(QUIT, NULL);
> -	add_handler(SHUTDOWN, NULL);
> -	add_handler(GETPRSTATUS+MAP, NULL);
> -	add_handler(SETPRSTATUS+MAP, NULL);
> -	add_handler(UNSETPRSTATUS+MAP, NULL);
> -	add_handler(GETPRKEY+MAP, NULL);
> -	add_handler(SETPRKEY+MAP+KEY, NULL);
> -	add_handler(UNSETPRKEY+MAP, NULL);
> -	add_handler(FORCEQ+DAEMON, NULL);
> -	add_handler(RESTOREQ+DAEMON, NULL);
> -	add_handler(SETMARGINAL+PATH, NULL);
> -	add_handler(UNSETMARGINAL+PATH, NULL);
> -	add_handler(UNSETMARGINAL+MAP, NULL);
> -
>  	return 0;
>  }
>  
> diff --git a/multipathd/cli.h b/multipathd/cli.h
> index 3dac1b4..479a745 100644
> --- a/multipathd/cli.h
> +++ b/multipathd/cli.h
> @@ -133,9 +133,10 @@ struct handler {
>  };
>  
>  int alloc_handlers (void);
> -int add_handler (uint64_t fp, cli_handler *fn);
> -int set_handler_callback (uint64_t fp, cli_handler *fn);
> -int set_unlocked_handler_callback (uint64_t fp, cli_handler *fn);
> +int __set_handler_callback (uint64_t fp, cli_handler *fn, bool locked);
> +#define set_handler_callback(fp, fn) __set_handler_callback(fp, fn, true)
> +#define set_unlocked_handler_callback(fp, fn) __set_handler_callback(fp, fn, false)
> +
>  int parse_cmd (char * cmd, char ** reply, int * len, void *, int);
>  int load_keys (void);
>  char * get_keyparam (vector v, uint64_t code);
> -- 
> 2.33.1