[dm-devel] [PATCH v2 24/24] multipath: use symbolic return value and exit code
Martin Wilck
mwilck at suse.com
Mon Dec 3 19:36:24 UTC 2018
Use an enum to represent the return code and exit status of
multipath and its most important subroutine, configure().
This clarifies the confusing use of booleans and status
codes a bit, hopefully.
This patch doesn't introduce a change in behavior.
Signed-off-by: Martin Wilck <mwilck at suse.com>
---
multipath/main.c | 120 ++++++++++++++++++++++++++---------------------
1 file changed, 66 insertions(+), 54 deletions(-)
diff --git a/multipath/main.c b/multipath/main.c
index eb087482..e437746d 100644
--- a/multipath/main.c
+++ b/multipath/main.c
@@ -68,6 +68,19 @@ int logsink;
struct udev *udev;
struct config *multipath_conf;
+/*
+ * Return values of configure(), print_cmd_valid(), and main().
+ * RTVL_{YES,NO} are synonyms for RTVL_{OK,FAIL} for the CMD_VALID_PATH case.
+ */
+enum {
+ RTVL_OK = 0,
+ RTVL_YES = RTVL_OK,
+ RTVL_FAIL = 1,
+ RTVL_NO = RTVL_FAIL,
+ RTVL_MAYBE, /* only used internally, never returned */
+ RTVL_RETRY, /* returned by configure(), not by main() */
+};
+
struct config *get_multipath_config(void)
{
return multipath_conf;
@@ -475,15 +488,14 @@ retry:
static int print_cmd_valid(int k, const vector pathvec,
struct config *conf)
{
- static const int vals[] = { 1, 0, 2 };
int wait = FIND_MULTIPATHS_NEVER;
struct timespec until;
struct path *pp;
- if (k < 0 || k >= (sizeof(vals) / sizeof(int)))
- return 1;
+ if (k != RTVL_YES && k != RTVL_NO && k != RTVL_MAYBE)
+ return RTVL_NO;
- if (k == 2) {
+ if (k == RTVL_MAYBE) {
/*
* Caller ensures that pathvec[0] is the path to
* examine.
@@ -493,7 +505,7 @@ static int print_cmd_valid(int k, const vector pathvec,
wait = find_multipaths_check_timeout(
pp, pp->find_multipaths_timeout, &until);
if (wait != FIND_MULTIPATHS_WAITING)
- k = 1;
+ k = RTVL_NO;
} else if (pathvec != NULL && (pp = VECTOR_SLOT(pathvec, 0)))
wait = find_multipaths_check_timeout(pp, 0, &until);
if (wait == FIND_MULTIPATHS_WAITING)
@@ -501,8 +513,10 @@ static int print_cmd_valid(int k, const vector pathvec,
until.tv_sec, until.tv_nsec/1000);
else if (wait == FIND_MULTIPATHS_WAIT_DONE)
printf("FIND_MULTIPATHS_WAIT_UNTIL=\"0\"\n");
- printf("DM_MULTIPATH_DEVICE_PATH=\"%d\"\n", vals[k]);
- return k == 1;
+ printf("DM_MULTIPATH_DEVICE_PATH=\"%d\"\n",
+ k == RTVL_MAYBE ? 2 : k == RTVL_YES ? 1 : 0);
+ /* Never return RTVL_MAYBE */
+ return k == RTVL_NO ? RTVL_NO : RTVL_YES;
}
/*
@@ -524,12 +538,6 @@ static bool released_to_systemd(void)
return ret;
}
-/*
- * Return value:
- * -1: Retry
- * 0: Success
- * 1: Failure
- */
static int
configure (struct config *conf, enum mpath_cmds cmd,
enum devtypes dev_type, char *devpath)
@@ -537,7 +545,7 @@ configure (struct config *conf, enum mpath_cmds cmd,
vector curmp = NULL;
vector pathvec = NULL;
struct vectors vecs;
- int r = 1, rc;
+ int r = RTVL_FAIL, rc;
int di_flag = 0;
char * refwwid = NULL;
char * dev = NULL;
@@ -585,21 +593,23 @@ configure (struct config *conf, enum mpath_cmds cmd,
goto out;
}
if (cmd == CMD_REMOVE_WWID) {
- r = remove_wwid(refwwid);
- if (r == 0)
+ rc = remove_wwid(refwwid);
+ if (rc == 0) {
printf("wwid '%s' removed\n", refwwid);
- else if (r == 1) {
+ r = RTVL_OK;
+ } else if (rc == 1) {
printf("wwid '%s' not in wwids file\n",
refwwid);
- r = 0;
+ r = RTVL_OK;
}
goto out;
}
if (cmd == CMD_ADD_WWID) {
- r = remember_wwid(refwwid);
- if (r >= 0)
+ rc = remember_wwid(refwwid);
+ if (rc >= 0) {
printf("wwid '%s' added\n", refwwid);
- else
+ r = RTVL_OK;
+ } else
printf("failed adding '%s' to wwids file\n",
refwwid);
goto out;
@@ -614,13 +624,13 @@ configure (struct config *conf, enum mpath_cmds cmd,
*/
if (cmd == CMD_VALID_PATH) {
if (is_failed_wwid(refwwid) == WWID_IS_FAILED) {
- r = 1;
+ r = RTVL_NO;
goto print_valid;
}
if ((!find_multipaths_on(conf) &&
ignore_wwids_on(conf)) ||
check_wwids_file(refwwid, 0) == 0)
- r = 0;
+ r = RTVL_YES;
if (!ignore_wwids_on(conf))
goto print_valid;
/* At this point, either r==0 or find_multipaths_on. */
@@ -630,7 +640,7 @@ configure (struct config *conf, enum mpath_cmds cmd,
* Quick check if path is already multipathed.
*/
if (sysfs_is_multipathed(VECTOR_SLOT(pathvec, 0))) {
- r = 0;
+ r = RTVL_YES;
goto print_valid;
}
@@ -644,10 +654,10 @@ configure (struct config *conf, enum mpath_cmds cmd,
* Leave DM_MULTIPATH_DEVICE_PATH="0".
*/
if (released) {
- r = 1;
+ r = RTVL_NO;
goto print_valid;
}
- if (r == 0)
+ if (r == RTVL_YES)
goto print_valid;
/* find_multipaths_on: Fall through to path detection */
}
@@ -703,13 +713,12 @@ configure (struct config *conf, enum mpath_cmds cmd,
* the refwwid, or there is more than one path matching
* the refwwid, then the path is valid */
if (VECTOR_SIZE(curmp) != 0) {
- r = 0;
+ r = RTVL_YES;
goto print_valid;
} else if (VECTOR_SIZE(pathvec) > 1)
- r = 0;
+ r = RTVL_YES;
else
- /* Use r=2 as an indication for "maybe" */
- r = 2;
+ r = RTVL_MAYBE;
/*
* If opening the path with O_EXCL fails, the path
@@ -739,13 +748,14 @@ configure (struct config *conf, enum mpath_cmds cmd,
/*
* Check if we raced with multipathd
*/
- r = !sysfs_is_multipathed(VECTOR_SLOT(pathvec, 0));
+ r = sysfs_is_multipathed(VECTOR_SLOT(pathvec, 0)) ?
+ RTVL_YES : RTVL_NO;
}
goto print_valid;
}
if (cmd != CMD_CREATE && cmd != CMD_DRY_RUN) {
- r = 0;
+ r = RTVL_OK;
goto out;
}
@@ -754,7 +764,7 @@ configure (struct config *conf, enum mpath_cmds cmd,
*/
rc = coalesce_paths(&vecs, NULL, refwwid,
conf->force_reload, cmd);
- r = rc == CP_RETRY ? -1 : rc == CP_OK ? 0 : 1;
+ r = rc == CP_RETRY ? RTVL_RETRY : rc == CP_OK ? RTVL_OK : RTVL_FAIL;
print_valid:
if (cmd == CMD_VALID_PATH)
@@ -855,7 +865,7 @@ main (int argc, char *argv[])
int arg;
extern char *optarg;
extern int optind;
- int r = 1;
+ int r = RTVL_FAIL;
enum mpath_cmds cmd = CMD_CREATE;
enum devtypes dev_type = DEV_NONE;
char *dev = NULL;
@@ -866,7 +876,7 @@ main (int argc, char *argv[])
logsink = 0;
conf = load_config(DEFAULT_CONFIGFILE);
if (!conf)
- exit(1);
+ exit(RTVL_FAIL);
multipath_conf = conf;
conf->retrigger_tries = 0;
while ((arg = getopt(argc, argv, ":adcChl::FfM:v:p:b:BrR:itTquUwW")) != EOF ) {
@@ -877,7 +887,7 @@ main (int argc, char *argv[])
if (sizeof(optarg) > sizeof(char *) ||
!isdigit(optarg[0])) {
usage (argv[0]);
- exit(1);
+ exit(RTVL_FAIL);
}
conf->verbosity = atoi(optarg);
@@ -924,7 +934,7 @@ main (int argc, char *argv[])
if (conf->pgpolicy_flag == IOPOLICY_UNDEF) {
printf("'%s' is not a valid policy\n", optarg);
usage(argv[0]);
- exit(1);
+ exit(RTVL_FAIL);
}
break;
case 'r':
@@ -934,14 +944,14 @@ main (int argc, char *argv[])
conf->find_multipaths |= _FIND_MULTIPATHS_I;
break;
case 't':
- r = dump_config(conf, NULL, NULL);
+ r = dump_config(conf, NULL, NULL) ? RTVL_FAIL : RTVL_OK;
goto out_free_config;
case 'T':
cmd = CMD_DUMP_CONFIG;
break;
case 'h':
usage(argv[0]);
- exit(0);
+ exit(RTVL_OK);
case 'u':
cmd = CMD_VALID_PATH;
dev_type = DEV_UEVENT;
@@ -965,20 +975,20 @@ main (int argc, char *argv[])
case ':':
fprintf(stderr, "Missing option argument\n");
usage(argv[0]);
- exit(1);
+ exit(RTVL_FAIL);
case '?':
fprintf(stderr, "Unknown switch: %s\n", optarg);
usage(argv[0]);
- exit(1);
+ exit(RTVL_FAIL);
default:
usage(argv[0]);
- exit(1);
+ exit(RTVL_FAIL);
}
}
if (getuid() != 0) {
fprintf(stderr, "need to be root\n");
- exit(1);
+ exit(RTVL_FAIL);
}
if (optind < argc) {
@@ -1016,7 +1026,8 @@ main (int argc, char *argv[])
/* Failing here is non-fatal */
init_foreign(conf->multipath_dir);
if (cmd == CMD_USABLE_PATHS) {
- r = check_usable_paths(conf, dev, dev_type);
+ r = check_usable_paths(conf, dev, dev_type) ?
+ RTVL_FAIL : RTVL_OK;
goto out;
}
if (cmd == CMD_VALID_PATH &&
@@ -1032,7 +1043,7 @@ main (int argc, char *argv[])
if (fd == -1) {
condlog(3, "%s: daemon is not running", dev);
if (!systemd_service_enabled(dev)) {
- r = print_cmd_valid(1, NULL, conf);
+ r = print_cmd_valid(RTVL_NO, NULL, conf);
goto out;
}
} else
@@ -1046,9 +1057,9 @@ main (int argc, char *argv[])
switch(delegate_to_multipathd(cmd, dev, dev_type, conf)) {
case DELEGATE_OK:
- exit(0);
+ exit(RTVL_OK);
case DELEGATE_ERROR:
- exit(1);
+ exit(RTVL_FAIL);
case NOT_DELEGATED:
break;
}
@@ -1064,8 +1075,8 @@ main (int argc, char *argv[])
goto out;
}
if (dm_get_maps(curmp) == 0)
- r = replace_wwids(curmp);
- if (r == 0)
+ r = replace_wwids(curmp) ? RTVL_FAIL : RTVL_OK;
+ if (r == RTVL_OK)
printf("successfully reset wwids\n");
vector_foreach_slot_backwards(curmp, mpp, i) {
vector_del_slot(curmp, i);
@@ -1078,17 +1089,18 @@ main (int argc, char *argv[])
retries = conf->remove_retries;
if (conf->remove == FLUSH_ONE) {
if (dev_type == DEV_DEVMAP) {
- r = dm_suspend_and_flush_map(dev, retries);
+ r = dm_suspend_and_flush_map(dev, retries) ?
+ RTVL_FAIL : RTVL_OK;
} else
condlog(0, "must provide a map name to remove");
goto out;
}
else if (conf->remove == FLUSH_ALL) {
- r = dm_flush_maps(retries);
+ r = dm_flush_maps(retries) ? RTVL_FAIL : RTVL_OK;
goto out;
}
- while ((r = configure(conf, cmd, dev_type, dev)) < 0)
+ while ((r = configure(conf, cmd, dev_type, dev)) == RTVL_RETRY)
condlog(3, "restart multipath configuration process");
out:
@@ -1103,8 +1115,8 @@ out:
* multipath -u must exit with status 0, otherwise udev won't
* import its output.
*/
- if (cmd == CMD_VALID_PATH && dev_type == DEV_UEVENT && r == 1)
- r = 0;
+ if (cmd == CMD_VALID_PATH && dev_type == DEV_UEVENT && r == RTVL_NO)
+ r = RTVL_OK;
if (dev_type == DEV_UEVENT)
closelog();
--
2.19.1
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