[dm-devel] [PATCH v2 1/7] libmultipath: make dm_get_map/status return codes symbolic
Benjamin Marzinski
bmarzins at redhat.com
Thu Jun 25 20:42:15 UTC 2020
dm_get_map() and dm_get_status() now use symbolic return codes. They
also differentiate between failing to get information from device-mapper
and not finding the requested device. These symboilc return codes are
also used by update_multipath_* functions.
Signed-off-by: Benjamin Marzinski <bmarzins at redhat.com>
---
libmultipath/devmapper.c | 51 +++++++++++++++++++++++++-------------
libmultipath/devmapper.h | 6 +++++
libmultipath/structs_vec.c | 45 +++++++++++++++++++--------------
multipathd/main.c | 12 ++++-----
4 files changed, 72 insertions(+), 42 deletions(-)
diff --git a/libmultipath/devmapper.c b/libmultipath/devmapper.c
index 27d52398..f5cfe296 100644
--- a/libmultipath/devmapper.c
+++ b/libmultipath/devmapper.c
@@ -534,36 +534,43 @@ int dm_map_present(const char * str)
int dm_get_map(const char *name, unsigned long long *size, char *outparams)
{
- int r = 1;
+ int r = DMP_ERR;
struct dm_task *dmt;
uint64_t start, length;
char *target_type = NULL;
char *params = NULL;
if (!(dmt = libmp_dm_task_create(DM_DEVICE_TABLE)))
- return 1;
+ return r;
if (!dm_task_set_name(dmt, name))
goto out;
dm_task_no_open_count(dmt);
- if (!dm_task_run(dmt))
+ errno = 0;
+ if (!dm_task_run(dmt)) {
+ if (errno == ENXIO)
+ r = DMP_FAIL;
goto out;
+ }
+ r = DMP_FAIL;
/* Fetch 1st target */
- dm_get_next_target(dmt, NULL, &start, &length,
- &target_type, ¶ms);
+ if (dm_get_next_target(dmt, NULL, &start, &length,
+ &target_type, ¶ms) != NULL)
+ /* more than one target */
+ goto out;
if (size)
*size = length;
if (!outparams) {
- r = 0;
+ r = DMP_PASS;
goto out;
}
if (snprintf(outparams, PARAMS_SIZE, "%s", params) <= PARAMS_SIZE)
- r = 0;
+ r = DMP_PASS;
out:
dm_task_destroy(dmt);
return r;
@@ -637,35 +644,45 @@ is_mpath_part(const char *part_name, const char *map_name)
int dm_get_status(const char *name, char *outstatus)
{
- int r = 1;
+ int r = DMP_ERR;
struct dm_task *dmt;
uint64_t start, length;
char *target_type = NULL;
char *status = NULL;
if (!(dmt = libmp_dm_task_create(DM_DEVICE_STATUS)))
- return 1;
+ return r;
if (!dm_task_set_name(dmt, name))
goto out;
dm_task_no_open_count(dmt);
- if (!dm_task_run(dmt))
+ errno = 0;
+ if (!dm_task_run(dmt)) {
+ if (errno == ENXIO)
+ r = DMP_FAIL;
goto out;
+ }
+ r = DMP_FAIL;
/* Fetch 1st target */
- dm_get_next_target(dmt, NULL, &start, &length,
- &target_type, &status);
+ if (dm_get_next_target(dmt, NULL, &start, &length,
+ &target_type, &status) != NULL)
+ goto out;
+
+ if (!target_type || strcmp(target_type, TGT_MPATH) != 0)
+ goto out;
+
if (!status) {
condlog(2, "get null status.");
goto out;
}
if (snprintf(outstatus, PARAMS_SIZE, "%s", status) <= PARAMS_SIZE)
- r = 0;
+ r = DMP_PASS;
out:
- if (r)
+ if (r != DMP_PASS)
condlog(0, "%s: error getting map status string", name);
dm_task_destroy(dmt);
@@ -920,7 +937,7 @@ int _dm_flush_map (const char * mapname, int need_sync, int deferred_remove,
return 1;
if (need_suspend &&
- !dm_get_map(mapname, &mapsize, params) &&
+ dm_get_map(mapname, &mapsize, params) == DMP_PASS &&
strstr(params, "queue_if_no_path")) {
if (!dm_queue_if_no_path(mapname, 0))
queue_if_no_path = 1;
@@ -1129,7 +1146,7 @@ struct multipath *dm_get_multipath(const char *name)
if (!mpp->alias)
goto out;
- if (dm_get_map(name, &mpp->size, NULL))
+ if (dm_get_map(name, &mpp->size, NULL) != DMP_PASS)
goto out;
dm_get_uuid(name, mpp->wwid, WWID_SIZE);
@@ -1313,7 +1330,7 @@ do_foreach_partmaps (const char * mapname,
/*
* and we can fetch the map table from the kernel
*/
- !dm_get_map(names->name, &size, ¶ms[0]) &&
+ dm_get_map(names->name, &size, ¶ms[0]) == DMP_PASS &&
/*
* and the table maps over the multipath map
diff --git a/libmultipath/devmapper.h b/libmultipath/devmapper.h
index 5ed7edc5..5b18bf4b 100644
--- a/libmultipath/devmapper.h
+++ b/libmultipath/devmapper.h
@@ -27,6 +27,12 @@
#define UUID_PREFIX "mpath-"
#define UUID_PREFIX_LEN (sizeof(UUID_PREFIX) - 1)
+enum {
+ DMP_ERR = -1,
+ DMP_PASS,
+ DMP_FAIL,
+};
+
void dm_init(int verbosity);
int dm_prereq(unsigned int *v);
void skip_libmp_dm_init(void);
diff --git a/libmultipath/structs_vec.c b/libmultipath/structs_vec.c
index 077f2e42..2225abeb 100644
--- a/libmultipath/structs_vec.c
+++ b/libmultipath/structs_vec.c
@@ -196,43 +196,47 @@ extract_hwe_from_path(struct multipath * mpp)
int
update_multipath_table (struct multipath *mpp, vector pathvec, int is_daemon)
{
+ int r = DMP_ERR;
char params[PARAMS_SIZE] = {0};
if (!mpp)
- return 1;
+ return r;
- if (dm_get_map(mpp->alias, &mpp->size, params)) {
- condlog(3, "%s: cannot get map", mpp->alias);
- return 1;
+ r = dm_get_map(mpp->alias, &mpp->size, params);
+ if (r != DMP_PASS) {
+ condlog(3, "%s: %s", mpp->alias, (r == DMP_ERR)? "error getting table" : "map not present");
+ return r;
}
if (disassemble_map(pathvec, params, mpp, is_daemon)) {
condlog(3, "%s: cannot disassemble map", mpp->alias);
- return 1;
+ return DMP_ERR;
}
- return 0;
+ return DMP_PASS;
}
int
update_multipath_status (struct multipath *mpp)
{
+ int r = DMP_ERR;
char status[PARAMS_SIZE] = {0};
if (!mpp)
- return 1;
+ return r;
- if (dm_get_status(mpp->alias, status)) {
- condlog(3, "%s: cannot get status", mpp->alias);
- return 1;
+ r = dm_get_status(mpp->alias, status);
+ if (r != DMP_PASS) {
+ condlog(3, "%s: %s", mpp->alias, (r == DMP_ERR)? "error getting status" : "map not present");
+ return r;
}
if (disassemble_status(status, mpp)) {
condlog(3, "%s: cannot disassemble status", mpp->alias);
- return 1;
+ return DMP_ERR;
}
- return 0;
+ return DMP_PASS;
}
void sync_paths(struct multipath *mpp, vector pathvec)
@@ -264,10 +268,10 @@ int
update_multipath_strings(struct multipath *mpp, vector pathvec, int is_daemon)
{
struct pathgroup *pgp;
- int i;
+ int i, r = DMP_ERR;
if (!mpp)
- return 1;
+ return r;
update_mpp_paths(mpp, pathvec);
condlog(4, "%s: %s", mpp->alias, __FUNCTION__);
@@ -276,18 +280,21 @@ update_multipath_strings(struct multipath *mpp, vector pathvec, int is_daemon)
free_pgvec(mpp->pg, KEEP_PATHS);
mpp->pg = NULL;
- if (update_multipath_table(mpp, pathvec, is_daemon))
- return 1;
+ r = update_multipath_table(mpp, pathvec, is_daemon);
+ if (r != DMP_PASS)
+ return r;
+
sync_paths(mpp, pathvec);
- if (update_multipath_status(mpp))
- return 1;
+ r = update_multipath_status(mpp);
+ if (r != DMP_PASS)
+ return r;
vector_foreach_slot(mpp->pg, pgp, i)
if (pgp->paths)
path_group_prio_update(pgp);
- return 0;
+ return DMP_PASS;
}
static void enter_recovery_mode(struct multipath *mpp)
diff --git a/multipathd/main.c b/multipathd/main.c
index 205ddb32..d73b1b9a 100644
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -418,7 +418,7 @@ int __setup_multipath(struct vectors *vecs, struct multipath *mpp,
goto out;
}
- if (update_multipath_strings(mpp, vecs->pathvec, 1)) {
+ if (update_multipath_strings(mpp, vecs->pathvec, 1) != DMP_PASS) {
condlog(0, "%s: failed to setup multipath", mpp->alias);
goto out;
}
@@ -557,9 +557,9 @@ add_map_without_path (struct vectors *vecs, const char *alias)
mpp->mpe = find_mpe(conf->mptable, mpp->wwid);
put_multipath_config(conf);
- if (update_multipath_table(mpp, vecs->pathvec, 1))
+ if (update_multipath_table(mpp, vecs->pathvec, 1) != DMP_PASS)
goto out;
- if (update_multipath_status(mpp))
+ if (update_multipath_status(mpp) != DMP_PASS)
goto out;
if (!vector_alloc_slot(vecs->mpvec))
@@ -1350,8 +1350,8 @@ map_discovery (struct vectors * vecs)
return 1;
vector_foreach_slot (vecs->mpvec, mpp, i)
- if (update_multipath_table(mpp, vecs->pathvec, 1) ||
- update_multipath_status(mpp)) {
+ if (update_multipath_table(mpp, vecs->pathvec, 1) != DMP_PASS ||
+ update_multipath_status(mpp) != DMP_PASS) {
remove_map(mpp, vecs, 1);
i--;
}
@@ -2091,7 +2091,7 @@ check_path (struct vectors * vecs, struct path * pp, unsigned int ticks)
/*
* Synchronize with kernel state
*/
- if (update_multipath_strings(pp->mpp, vecs->pathvec, 1)) {
+ if (update_multipath_strings(pp->mpp, vecs->pathvec, 1) != DMP_PASS) {
condlog(1, "%s: Could not synchronize with kernel state",
pp->dev);
pp->dmstate = PSTATE_UNDEF;
--
2.17.2
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