Balbir Singh wrote:
* Ivana Varekova <[email protected]> [2009-02-03 09:12:38]:
Balbir Singh wrote:
* [email protected] <[email protected]> [2009-02-02 13:22:47]:
This patch standardize error messages form of the second part of cgclassify.
Signed-off-by: Ivana Varekova <[email protected]>
The patch looks good, but the approach we've thought of for the longer
run is different. We want to save errno to a special thread specific
variable. In the configuration errno does not have to be thread
specific, since we don't allow threads to parse a configuration file
in parallel. Instead of the adding new error codes, could you please
add the capability to save errno and print it out on error?
OK I will change it.
Ivana Varekova
Thanks, Ivana!
The patch is attached, I hope it's OK this way.
Signed-off-by: Ivana Varekova <varek...@re...>
Revewed-by: Jan Safranek <jsafr...@re...>
diff -up ./api.c.orig ./api.c
--- ./api.c.orig 2009-02-06 13:51:40.000000000 +0100
+++ ./api.c 2009-02-13 09:38:40.000000000 +0100
@@ -48,6 +48,15 @@
#define VERSION(ver) #ver
+/* the errno which happend the last time
+ * (have to be thread specific) */
+__thread int last_errno;
+
+#define MAXLEN 256
+
+/* the value have to be thread specific */
+__thread char errtext[MAXLEN];
+
/*
* Remember to bump this up for major API changes.
*/
@@ -94,6 +103,7 @@ char *cgroup_strerror_codes[] = {
"Cgroup parsing failed",
"Cgroup, rules file does not exist",
"Cgroup mounting failed",
+ "The config file can not be opend",
};
static int cg_chown_file(FTS *fts, FTSENT *ent, uid_t owner, gid_t group)
@@ -294,14 +304,16 @@ static int cgroup_parse_rules(bool cache
dbg("Failed to open configuration file %s with"
" error: %s\n", CGRULES_CONF_FILE,
strerror(errno));
- ret = errno;
+ last_errno = errno;
+ ret = ECGCANTOPENCF;
goto finish;
}
buff = calloc(CGROUP_RULE_MAXLINE, sizeof(char));
if (!buff) {
dbg("Out of memory? Error: %s\n", strerror(errno));
- ret = errno;
+ last_errno = errno;
+ ret = ECGOTHER;
goto close_unlock;
}
@@ -442,7 +454,8 @@ static int cgroup_parse_rules(bool cache
newrule = calloc(1, sizeof(struct cgroup_rule));
if (!newrule) {
dbg("Out of memory? Error: %s\n", strerror(errno));
- ret = errno;
+ last_errno = errno;
+ ret = ECGOTHER;
goto cleanup;
}
@@ -565,6 +578,7 @@ int cgroup_init()
*/
buf = malloc(FILENAME_MAX);
if (!buf) {
+ last_errno = errno;
ret = ECGOTHER;
goto unlock_exit;
}
@@ -777,11 +791,13 @@ int cgroup_attach_task_pid(struct cgroup
dbg("Error writing tid %d to %s:%s\n",
tid, path, strerror(errno));
fclose(tasks);
+ last_errno = errno;
return ECGOTHER;
}
ret = fflush(tasks);
if (ret) {
+ last_errno = errno;
dbg("Error writing tid %d to %s:%s\n",
tid, path, strerror(errno));
fclose(tasks);
@@ -822,6 +838,7 @@ int cgroup_attach_task_pid(struct cgroup
}
ret = fprintf(tasks, "%d", tid);
if (ret < 0) {
+ last_errno = errno;
dbg("Error writing tid %d to %s:%s\n",
tid, path, strerror(errno));
fclose(tasks);
@@ -829,6 +846,7 @@ int cgroup_attach_task_pid(struct cgroup
}
ret = fflush(tasks);
if (ret) {
+ last_errno = errno;
dbg("Error writing tid %d to %s:%s\n",
tid, path, strerror(errno));
fclose(tasks);
@@ -872,12 +890,16 @@ static int cg_mkdir_p(const char *path)
buf = getcwd(cwd, FILENAME_MAX);
- if (!buf)
+ if (!buf) {
+ last_errno = errno;
return ECGOTHER;
+ }
real_path = strdup(path);
- if (!real_path)
+ if (!real_path) {
+ last_errno = errno;
return ECGOTHER;
+ }
do {
while (real_path[j] != '\0' && real_path[j] != '/')
@@ -892,6 +914,7 @@ static int cg_mkdir_p(const char *path)
ret = mkdir(str, S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
wd = strdup(str);
if (!wd) {
+ last_errno = errno;
ret = ECGOTHER;
break;
}
@@ -1030,6 +1053,7 @@ int cgroup_modify_cgroup(struct cgroup *
ret = asprintf(&path, "%s%s", base,
cgroup->controller[i]->values[j]->name);
if (ret < 0) {
+ last_errno = errno;
error = ECGOTHER;
goto err;
}
@@ -1175,6 +1199,7 @@ int cgroup_create_cgroup(struct cgroup *
base = strdup(path);
if (!base) {
+ last_errno = errno;
error = ECGOTHER;
goto err;
}
@@ -1191,6 +1216,7 @@ int cgroup_create_cgroup(struct cgroup *
ret = asprintf(&path, "%s%s", base,
cgroup->controller[k]->values[j]->name);
if (ret < 0) {
+ last_errno = errno;
error = ECGOTHER;
goto err;
}
@@ -1215,12 +1241,14 @@ int cgroup_create_cgroup(struct cgroup *
free(path);
ret = asprintf(&path, "%s/tasks", base);
if (ret < 0) {
+ last_errno = errno;
error = ECGOTHER;
goto err;
}
error = chown(path, cgroup->tasks_uid,
cgroup->tasks_gid);
if (error) {
+ last_errno = errno;
error = ECGOTHER;
goto err;
}
@@ -1403,6 +1431,7 @@ int cgroup_delete_cgroup(struct cgroup *
cgroup->controller[i]->name))
continue;
error = rmdir(path);
+ last_errno = errno;
}
open_err:
if (ignore_migration) {
@@ -1411,8 +1440,10 @@ open_err:
cgroup->controller[i]->name))
continue;
error = rmdir(path);
- if (error < 0 && errno == ENOENT)
+ if (error < 0 && errno == ENOENT) {
+ last_errno = errno;
error = 0;
+ }
}
}
if (error)
@@ -1441,8 +1472,10 @@ static int cg_rd_ctrl_file(char *subsys,
return ECGROUPVALUENOTEXIST;
*value = malloc(CG_VALUE_MAX);
- if (!*value)
+ if (!*value) {
+ last_errno = errno;
return ECGOTHER;
+ }
/*
* using %as crashes when we try to read from files like
@@ -1596,11 +1629,13 @@ int cgroup_get_cgroup(struct cgroup *cgr
ret = asprintf(&control_path, "%s/tasks", path);
if (ret < 0) {
+ last_errno = errno;
error = ECGOTHER;
goto unlock_error;
}
if (stat(control_path, &stat_buffer)) {
+ last_errno = errno;
free(control_path);
error = ECGOTHER;
goto unlock_error;
@@ -1620,6 +1655,7 @@ int cgroup_get_cgroup(struct cgroup *cgr
dir = opendir(path);
if (!dir) {
+ last_errno = errno;
error = ECGOTHER;
goto unlock_error;
}
@@ -1739,8 +1775,10 @@ static int cg_prepare_controller_array(c
if (temp) {
controllers[j] = strdup(temp);
- if (!controllers[j])
+ if (!controllers[j]) {
+ last_errno = errno;
return ECGOTHER;
+ }
}
j++;
} while (temp);
@@ -2137,6 +2175,7 @@ int cgroup_get_current_controller_path(p
*/
if (ret != 3 || ret == EOF) {
dbg("read failed for pid_cgroup_fd ret %d\n", ret);
+ last_errno = errno;
ret = ECGOTHER;
goto done;
}
@@ -2147,6 +2186,7 @@ int cgroup_get_current_controller_path(p
== 0) {
*current_path = strdup(cgroup_path);
if (!*current_path) {
+ last_errno = errno;
ret = ECGOTHER;
goto done;
}
@@ -2168,5 +2208,19 @@ cleanup_path:
char *cgroup_strerror(int code)
{
assert((code >= ECGROUPNOTCOMPILED) && (code < ECGSENTINEL));
+ if ((code == ECGOTHER) || (code == ECGCANTOPENCF)) {
+ snprintf(errtext, MAXLEN, "%s: %s",
+ cgroup_strerror_codes[code % ECGROUPNOTCOMPILED],
+ strerror(cgroup_get_last_errno()));
+ return errtext;
+ }
return cgroup_strerror_codes[code % ECGROUPNOTCOMPILED];
}
+
+/**
+ * Return last errno, which caused ECGOTHER/ECGCANTOPENCF error.
+ */
+int cgroup_get_last_errno()
+{
+ return last_errno;
+}
diff -up ./cgclassify.c.orig ./cgclassify.c
--- ./cgclassify.c.orig 2009-02-06 13:51:40.000000000 +0100
+++ ./cgclassify.c 2009-02-13 09:29:49.000000000 +0100
@@ -140,7 +140,8 @@ int main(int argc, char *argv[])
ret = cgroup_change_cgroup_uid_gid(euid, egid, pid);
if (ret) {
fprintf(stderr, "Error: change of cgroup failed for"
- " pid %d\n", pid);
+ " pid %d: %s\n",
+ pid, cgroup_strerror(ret));
return ret;
}
}
diff -up ./libcgroup.h.orig ./libcgroup.h
--- ./libcgroup.h.orig 2009-02-06 13:51:40.000000000 +0100
+++ ./libcgroup.h 2009-02-13 09:30:08.000000000 +0100
@@ -88,12 +88,13 @@ enum cgroup_errors {
/* Represents error coming from other libraries like glibc. libcgroup
* users need to check errno upon encoutering ECGOTHER.
*/
- ECGOTHER,
+ ECGOTHER, /* OS error, see errno */
ECGROUPNOTEQUAL,
ECGCONTROLLERNOTEQUAL,
ECGROUPPARSEFAIL, /* Failed to parse rules configuration file. */
ECGROUPNORULES, /* Rules list does not exist. */
ECGMOUNTFAIL,
+ ECGCANTOPENCF, /* OS error, see errno */
ECGSENTINEL, /* Please insert further error codes above this */
};
@@ -195,6 +196,12 @@ int cgroup_get_current_controller_path(p
*/
char *cgroup_strerror(int code);
+/**
+ * Return last errno, which caused ECGOTHER error.
+ */
+int cgroup_get_last_errno();
+
+
/* The wrappers for filling libcg structures */
struct cgroup *cgroup_new_cgroup(const char *name);
diff -up ./libcgroup.map.orig ./libcgroup.map
--- ./libcgroup.map.orig 2009-02-06 13:51:40.000000000 +0100
+++ ./libcgroup.map 2009-02-10 11:19:27.000000000 +0100
@@ -44,4 +44,5 @@ local:
CGROUP_0.32.1 {
global:
cgroup_strerror;
+ cgroup_get_last_errno;
} CGROUP_0.32;
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