[LTP] [PATCH v2 2/2] msgget03: don't depend on existed shared resources

[Cyril Hrubis]

Hi!
> From 2772f8f0bbc1526389cb2090895dded41e2c43dc Mon Sep 17 00:00:00 2001
> From: Yang Xu <xuyang2018.jy@fujitsu.com>
> Date: Tue, 27 Jul 2021 16:22:42 +0800
> Subject: [PATCH] libs/libnewipc:Rename get_used_queues as get_used_sysvipc_cnt
> 
> Rename get_used_queues as get_used_sysvipc_cnt, so we can use GET_USED_QUEQUES()
> and GET_USED_SEGMENTS() to get the corresponding used sysvipc resource total.
> 
> Then we can use them in shmget03/msgget03, so we can trigger the ENOSPC error correctly
> even current environment has consume some sysvipc resource.
> 
> I don't use this api in verify function since we don't support run cases in parallel and
> we should assume this situation that this case is the only case to use(free or alloc) sysv
> ipc resource at that time.
> 
> Fixes: #842
> Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com>
> ---
>  include/libnewipc.h                             |  6 ++++--
>  libs/libltpnewipc/libnewipc.c                   | 16 ++++++++--------
>  testcases/kernel/syscalls/ipc/msgget/msgget03.c | 10 +++++++---
>  testcases/kernel/syscalls/ipc/shmget/shmget03.c | 10 ++++++----
>  4 files changed, 25 insertions(+), 17 deletions(-)
> 
> diff --git a/include/libnewipc.h b/include/libnewipc.h
> index 075364f85..b0448841a 100644
> --- a/include/libnewipc.h
> +++ b/include/libnewipc.h
> @@ -49,9 +49,11 @@ key_t getipckey(const char *file, const int lineno);
>  #define GETIPCKEY() \
>  	getipckey(__FILE__, __LINE__)
>  
> -int get_used_queues(const char *file, const int lineno);
> +int get_used_sysvipc_cnt(const char *file, const int lineno, const char *sysvipc_file);
>  #define GET_USED_QUEUES() \
> -	get_used_queues(__FILE__, __LINE__)
> +	get_used_sysvipc_cnt(__FILE__, __LINE__, "/proc/sysvipc/msg")
> +#define GET_USED_SEGMENTS() \
> +	get_used_sysvipc_cnt(__FILE__, __LINE__, "/proc/sysvipc/shm")

I would just call it get_used_sysvipc()

>  void *probe_free_addr(const char *file, const int lineno);
>  #define PROBE_FREE_ADDR() \
> diff --git a/libs/libltpnewipc/libnewipc.c b/libs/libltpnewipc/libnewipc.c
> index d0974bbe0..687a907e7 100644
> --- a/libs/libltpnewipc/libnewipc.c
> +++ b/libs/libltpnewipc/libnewipc.c
> @@ -48,25 +48,25 @@ key_t getipckey(const char *file, const int lineno)
>  	return key;
>  }
>  
> -int get_used_queues(const char *file, const int lineno)
> +int get_used_sysvipc_cnt(const char *file, const int lineno, const char *sysvipc_file)
>  {
>  	FILE *fp;
> -	int used_queues = -1;
> +	int used_cnt = -1;

And here as well the _cnt is not adding any value over I would say.

>  	char buf[BUFSIZE];
>  
> -	fp = safe_fopen(file, lineno, NULL, "/proc/sysvipc/msg", "r");
> +	fp = safe_fopen(file, lineno, NULL, sysvipc_file, "r");
>  
>  	while (fgets(buf, BUFSIZE, fp) != NULL)
> -		used_queues++;
> +		used_cnt++;
>  
>  	fclose(fp);
>  
> -	if (used_queues < 0) {
> -		tst_brk(TBROK, "can't read /proc/sysvipc/msg to get "
> -			"used message queues at %s:%d", file, lineno);
> +	if (used_cnt < 0) {
> +		tst_brk(TBROK, "can't read %s to get used message queues "
> +			"at %s:%d", sysvipc_file, file, lineno);
>  	}
>  
> -	return used_queues;
> +	return used_cnt;
>  }
>  
>  void *probe_free_addr(const char *file, const int lineno)
> diff --git a/testcases/kernel/syscalls/ipc/msgget/msgget03.c b/testcases/kernel/syscalls/ipc/msgget/msgget03.c
> index ab5714cdc..8ccffc547 100644
> --- a/testcases/kernel/syscalls/ipc/msgget/msgget03.c
> +++ b/testcases/kernel/syscalls/ipc/msgget/msgget03.c
> @@ -21,7 +21,7 @@
>  #include "tst_safe_sysv_ipc.h"
>  #include "libnewipc.h"
>  
> -static int maxmsgs, queue_cnt;
> +static int maxmsgs, queue_cnt, existed_cnt;
                                  ^
				  Why not 'used_cnt' ?
>  static int *queues;
>  static key_t msgkey;
>  
> @@ -37,11 +37,15 @@ static void setup(void)
>  
>  	msgkey = GETIPCKEY();
>  
> +	existed_cnt = GET_USED_QUEUES();
> +	tst_res(TINFO, "Current environment %d message queues are already in use",
> +		existed_cnt);
> +
>  	SAFE_FILE_SCANF("/proc/sys/kernel/msgmni", "%i", &maxmsgs);
>  
> -	queues = SAFE_MALLOC(maxmsgs * sizeof(int));
> +	queues = SAFE_MALLOC((maxmsgs - existed_cnt) * sizeof(int));
>  
> -	for (num = 0; num < maxmsgs; num++) {
> +	for (num = 0; num < maxmsgs - existed_cnt; num++) {
>  		res = msgget(msgkey + num, IPC_CREAT | IPC_EXCL);
>  		if (res == -1)
>  			tst_brk(TBROK | TERRNO, "msgget failed unexpectedly");
> diff --git a/testcases/kernel/syscalls/ipc/shmget/shmget03.c b/testcases/kernel/syscalls/ipc/shmget/shmget03.c
> index efbc465e1..acd352796 100644
> --- a/testcases/kernel/syscalls/ipc/shmget/shmget03.c
> +++ b/testcases/kernel/syscalls/ipc/shmget/shmget03.c
> @@ -22,7 +22,7 @@
>  #include "libnewipc.h"
>  
>  static int *queues;
> -static int maxshms, queue_cnt;
> +static int maxshms, queue_cnt, existed_cnt;
                                   ^
				   Here as well.
>  static key_t shmkey;
>  
>  static void verify_shmget(void)
> @@ -36,11 +36,13 @@ static void setup(void)
>  	int res, num;
>  
>  	shmkey = GETIPCKEY();
> -
> +	existed_cnt = GET_USED_SEGMENTS();
> +	tst_res(TINFO, "Current environment %d shared memory segments are already in use",
> +		existed_cnt);
>  	SAFE_FILE_SCANF("/proc/sys/kernel/shmmni", "%i", &maxshms);
>  
> -	queues = SAFE_MALLOC(maxshms * sizeof(int));
> -	for (num = 0; num < maxshms; num++) {
> +	queues = SAFE_MALLOC((maxshms - existed_cnt) * sizeof(int));
> +	for (num = 0; num < maxshms - existed_cnt; num++) {
>  		res = shmget(shmkey + num, SHM_SIZE, IPC_CREAT | IPC_EXCL | SHM_RW);
>  		if (res == -1)
>  			tst_brk(TBROK | TERRNO, "shmget failed unexpectedly");

Other than the very minor differencies I would do in naming the
variables and function this looks good to me.

Reviewed-by: Cyril Hrubis <chrubis@suse.cz>


-- 
Cyril Hrubis
chrubis@suse.cz