Re: [LTP] [PATCH v2] syscalls/{fanotify17, getxattr05}: Fix the ENOSPC error

[Cyril Hrubis <chrubis@suse.cz>]

Hi!
> If the value of max_user_namespaces is set to 10 but more than
> 10 user namspaces are currently used on system.  In this case,
> these tests fail with ENOSPC. for example:

What about we add a functionality to increment syfs files to the
save_restore API? I guess that this is going to be a pattern that we
have in several tests already.

Should look like (beware untested):

diff --git a/include/tst_sys_conf.h b/include/tst_sys_conf.h
index a221a9a0d..b84f05a50 100644
--- a/include/tst_sys_conf.h
+++ b/include/tst_sys_conf.h
@@ -12,6 +12,7 @@
 #define TST_SR_TBROK_RO 0x4
 #define TST_SR_SKIP_RO 0x8
 #define TST_SR_IGNORE_ERR 0x10
+#define TST_SR_INC 0x20

 #define TST_SR_TCONF (TST_SR_TCONF_MISSING | TST_SR_TCONF_RO)
 #define TST_SR_TBROK (TST_SR_TBROK_MISSING | TST_SR_TBROK_RO)
diff --git a/lib/tst_sys_conf.c b/lib/tst_sys_conf.c
index 80cd83569..5d1de241a 100644
--- a/lib/tst_sys_conf.c
+++ b/lib/tst_sys_conf.c
@@ -55,6 +55,8 @@ void tst_sys_conf_save_str(const char *path, const char *value)
 int tst_sys_conf_save(const struct tst_path_val *conf)
 {
        char line[PATH_MAX];
+       char inc_val[32];
+       const char *new_val = conf->val;
        int ttype, iret;
        FILE *fp;
        void *ret;
@@ -105,7 +107,35 @@ int tst_sys_conf_save(const struct tst_path_val *conf)

        tst_sys_conf_save_str(conf->path, line);

-       if (!conf->val)
+
+       if (conf->flags & TST_SR_INC) {
+               long orig, inc;
+
+               if (!conf->val) {
+                       tst_brk(TBROK, "Increment value not defined!");
+               }
+
+               if (tst_parse_long(line, &orig, LONG_MIN, LONG_MAX)) {
+                       tst_brk(TBROK | TERRNO,
+                               "Failed to convert '%s' to long",
+                               conf->path);
+               }
+
+               if (tst_parse_long(line, &inc, LONG_MIN, LONG_MAX)) {
+                       tst_brk(TBROK | TERRNO,
+                               "Failed to convert increment (%s) for '%s' to long",
+                               conf->val, conf->path);
+               }
+
+               //TODO: Overflow?
+               orig += inc;
+
+               snprintf(inc_val, sizeof(inc_val), "%li", orig);
+
+               new_val = inc_val;
+       }
+
+       if (!new_val)
                return 0;

        fp = fopen(conf->path, "w");
@@ -116,7 +146,7 @@ int tst_sys_conf_save(const struct tst_path_val *conf)
                return 0;
        }

-       iret = fputs(conf->val, fp);
+       iret = fputs(new_val, fp);

        if (iret < 0) {
                print_error(__LINE__, conf->flags & TST_SR_IGNORE_ERR,


After this patch the val in tst_path_val is going to be interpreted as
an increment with TST_SR_INC flag.

-- 
Cyril Hrubis
chrubis@suse.cz

-- 
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