From: Martin Wilck <mwilck@xxxxxxxx>
With the introduction of INIT_REMOVED, we have to deal with the situation
when a path is re-added in this state. This enables us to detect the
situation where a path is added while still part of a map after a failed
removal, which we couldn't before. Dealing with this correctly requires
some additional logic. There's a good case (re-added path is still mapped
by a map with matching WWID) and a bad case (non-matching WWID).
The logic is very similar in uev_add_path() and cli_add_path().
Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
---
multipathd/cli_handlers.c | 49 +++++++++++++++++++++++++++++++++--
multipathd/main.c | 54 ++++++++++++++++++++++++++++++++++++---
2 files changed, 97 insertions(+), 6 deletions(-)
diff --git a/multipathd/cli_handlers.c b/multipathd/cli_handlers.c
index 782bb00..679fd57 100644
--- a/multipathd/cli_handlers.c
+++ b/multipathd/cli_handlers.c
@@ -713,11 +713,56 @@ cli_add_path (void * v, char ** reply, int * len, void * data)
goto blacklisted;
pp = find_path_by_dev(vecs->pathvec, param);
- if (pp) {
+ if (pp && pp->initialized != INIT_REMOVED) {
condlog(2, "%s: path already in pathvec", param);
if (pp->mpp)
return 0;
- } else {
+ } else if (pp) {
+ /* Trying to add a path in INIT_REMOVED state */
+ struct multipath *prev_mpp;
+
+ prev_mpp = pp->mpp;
+ pp->mpp = NULL;
+ pp->initialized = INIT_NEW;
+ pp->wwid[0] = '\0';
+ conf = get_multipath_config();
+ pthread_cleanup_push(put_multipath_config, conf);
+ r = pathinfo(pp, conf, DI_ALL | DI_BLACKLIST);
+ pthread_cleanup_pop(1);
+
+ if (prev_mpp) {
+ /* Similar logic as in uev_add_path() */
+ pp->mpp = prev_mpp;
+ if (r == PATHINFO_OK &&
+ !strncmp(prev_mpp->wwid, pp->wwid, WWID_SIZE)) {
+ condlog(2, "%s: path re-added to %s", pp->dev,
+ pp->mpp->alias);
+ return 0;
+ } else if (!ev_remove_path(pp, vecs, true))
+ /* Path removed in ev_remove_path() */
+ pp = NULL;
+ else {
+ /* Init state is now INIT_REMOVED again */
+ pp->dmstate = PSTATE_FAILED;
+ dm_fail_path(pp->mpp->alias, pp->dev_t);
+ condlog(1, "%s: failed to re-add path still mapped in %s",
+ pp->dev, pp->mpp->alias);
+ return 1;
+ }
+ } else {
+ switch (r) {
+ case PATHINFO_SKIPPED:
+ goto blacklisted;
+ case PATHINFO_OK:
+ break;
+ default:
+ condlog(0, "%s: failed to get pathinfo", param);
+ return 1;
+ }
+ }
+ }
+
+ if (!pp) {
struct udev_device *udevice;
udevice = udev_device_new_from_subsystem_sysname(udev,
diff --git a/multipathd/main.c b/multipathd/main.c
index 545eb6d..7b2d320 100644
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -842,9 +842,21 @@ uev_add_path (struct uevent *uev, struct vectors * vecs, int need_do_map)
pp = find_path_by_dev(vecs->pathvec, uev->kernel);
if (pp) {
int r;
+ struct multipath *prev_mpp = NULL;
+ bool was_removed = pp->initialized == INIT_REMOVED;
+
+ if (was_removed) {
+ condlog(3, "%s: re-adding removed path", pp->dev);
+ pp->initialized = INIT_NEW;
+ prev_mpp = pp->mpp;
+ pp->mpp = NULL;
+ /* make sure get_uid() is called */
+ pp->wwid[0] = '\0';
+ } else
+ condlog(3,
+ "%s: spurious uevent, path already in pathvec",
+ uev->kernel);
- condlog(3, "%s: spurious uevent, path already in pathvec",
- uev->kernel);
if (!pp->mpp && !strlen(pp->wwid)) {
condlog(3, "%s: reinitialize path", uev->kernel);
udev_device_unref(pp->udev);
@@ -854,9 +866,43 @@ uev_add_path (struct uevent *uev, struct vectors * vecs, int need_do_map)
r = pathinfo(pp, conf,
DI_ALL | DI_BLACKLIST);
pthread_cleanup_pop(1);
- if (r == PATHINFO_OK)
+ if (r == PATHINFO_OK && !prev_mpp)
ret = ev_add_path(pp, vecs, need_do_map);
- else if (r == PATHINFO_SKIPPED) {
+ else if (r == PATHINFO_OK &&
+ !strncmp(pp->wwid, prev_mpp->wwid, WWID_SIZE)) {
+ /*
+ * Path was unsuccessfully removed, but now
+ * re-added, and still belongs to the right map
+ * - all fine.
+ */
+ pp->mpp = prev_mpp;
+ ret = 0;
+ } else if (prev_mpp) {
+ /*
+ * Bad: re-added path still hangs in wrong map
+ * Make another attempt to remove the path
+ */
+ pp->mpp = prev_mpp;
+ ret = ev_remove_path(pp, vecs, true);
+ if (r == PATHINFO_OK && !ret)
+ /*
+ * Path successfully freed, move on to
+ * "new path" code path below
+ */
+ pp = NULL;
+ else {
+ /*
+ * Failure in ev_remove_path will keep
+ * path in pathvec in INIT_REMOVED state
+ * Fail the path to make sure it isn't
+ * used any more.
+ */
+ pp->dmstate = PSTATE_FAILED;
+ dm_fail_path(pp->mpp->alias, pp->dev_t);
+ condlog(1, "%s: failed to re-add path still mapped in %s",
+ pp->dev, pp->mpp->alias);
+ }
+ } else if (r == PATHINFO_SKIPPED) {
condlog(3, "%s: remove blacklisted path",
uev->kernel);
i = find_slot(vecs->pathvec, (void *)pp);
--
2.26.2
--
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