[RFC PATCH]lvmlockd: try to adopt the lock resources left in previous lockspace

* [RFC PATCH]lvmlockd: try to adopt the lock resources left in previous lockspace
@ 2022-09-28  8:58 Lidong Zhong
  2022-09-28 22:00 ` David Teigland
  0 siblings, 1 reply; 3+ messages in thread
From: Lidong Zhong @ 2022-09-28  8:58 UTC (permalink / raw)
  To: lvm-devel

Hi David,

Could you share your opinion about this patch please? It's related to 
the patch I sent for resource-agents.

https://github.com/ClusterLabs/resource-agents/pull/1808

-----------------------------

If lvmlockd in cluster is killed accidently or any other reason, the
lock resources will become orphaned in the VG lockspace. When the
cluster manager tries to restart this daemon, the LVs will probably
become inactive because of resource schedule policy and thus the lock
resouce will be omited during the adoption process. This patch will
check if the lock is left in previous lockspace and if it matches one
entry in the adopt file, lvmlockd will also try to adopt it to prevent
further resource failure.
---
 ?daemons/lvmlockd/lvmlockd-core.c???? | 30 +++++++++--
 ?daemons/lvmlockd/lvmlockd-dlm.c????? | 75 ++++++++++++++++++++++++++++
 ?daemons/lvmlockd/lvmlockd-internal.h |? 1 +
 ?3 files changed, 101 insertions(+), 5 deletions(-)

diff --git a/daemons/lvmlockd/lvmlockd-core.c 
b/daemons/lvmlockd/lvmlockd-core.c
index 6d0d4d98c..820bba966 100644
--- a/daemons/lvmlockd/lvmlockd-core.c
+++ b/daemons/lvmlockd/lvmlockd-core.c
@@ -511,7 +511,7 @@ static struct client *alloc_client(void)
 ???? return cl;
 ?}

-static struct resource *alloc_resource(void)
+struct resource *alloc_resource(void)
 ?{
 ???? struct resource *r;

@@ -5308,10 +5308,10 @@ static int match_dm_uuid(char *dm_uuid, char 
*lv_lock_uuid)
 ? * will have locks adopted.
 ? */

-static int remove_inactive_lvs(struct list_head *vg_lockd)
+static int remove_inactive_lvs(struct list_head *vg_lockd, struct 
list_head *ls_found)
 ?{
-??? struct lockspace *ls;
-??? struct resource *r, *rsafe;
+??? struct lockspace *ls, *ls1;
+??? struct resource *r, *rsafe, *r1;
 ???? struct dm_names *names;
 ???? struct dm_task *dmt;
 ???? char *dm_uuid;
@@ -5396,6 +5396,19 @@ next_dmname:
 ???? } while (next);

 ?out:
+??? /* Try to adopt the lock resources left in the lockspace */
+??? list_for_each_entry(ls, vg_lockd, list) {
+??? ??? list_for_each_entry(ls1, ls_found, list) {
+??? ??? ??? if (strcmp(ls->vg_name, ls1->vg_name))
+??? ??? ??? ??? continue;
+??? ??? ??? list_for_each_entry(r, &ls->resources, list) {
+??? ??? ??? ??? list_for_each_entry(r1, &ls1->resources, list) {
+??? ??? ??? ??? ??? if (!strcmp(r->name, r1->name))
+??? ??? ??? ??? ??????? r->adopt = 1;
+??? ??? ??? ??? }
+??? ??? ??? }
+??????? }
+??? }
 ???? /* Remove any struct resources that do not need locks adopted. */
 ???? list_for_each_entry(ls, vg_lockd, list) {
 ???? ??? list_for_each_entry_safe(r, rsafe, &ls->resources, list) {
@@ -5408,6 +5421,13 @@ out:
 ???? ??? ??? }
 ???? ??? }
 ???? }
+??? /* Remove any resources in ls_found as the resources will be 
collected later from vg_lockd. */
+??? list_for_each_entry(ls, ls_found, list) {
+??? ??? list_for_each_entry_safe(r, rsafe, &ls->resources, list) {
+??? ??? ??? list_del(&r->list);
+??? ??? ??? free_resource(r);
+??? ??? }
+??? }
 ?ret:
 ???? dm_task_destroy(dmt);
 ???? return rv;
@@ -5477,7 +5497,7 @@ static void adopt_locks(void)
 ???? ?* resource struct, if not free the resource struct.
 ???? ?* The remain entries need to have locks adopted.
 ???? ?*/
-??? rv = remove_inactive_lvs(&vg_lockd);
+??? rv = remove_inactive_lvs(&vg_lockd, &ls_found);
 ???? if (rv < 0) {
 ???? ??? log_error("adopt_locks remove_inactive_lvs failed");
 ???? ??? goto fail;
diff --git a/daemons/lvmlockd/lvmlockd-dlm.c 
b/daemons/lvmlockd/lvmlockd-dlm.c
index 1305c3dc2..26089b118 100644
--- a/daemons/lvmlockd/lvmlockd-dlm.c
+++ b/daemons/lvmlockd/lvmlockd-dlm.c
@@ -737,6 +737,79 @@ int lm_hosts_dlm(struct lockspace *ls, int notify)
 ???? return count - 1;
 ?}

+
+/*
+ * collect the resources for later use in remove_inactive_lvs()
+ * code is borrowed from libdlm
+ */
+#define LOCK_LINE_MAX 1024
+static int lm_get_resources_dlm(struct list_head *ls_rejoin)
+{
+??? struct lockspace *ls;
+??? struct resource *r;
+??? FILE *file = NULL;
+??? char path[PATH_MAX];
+??? char line[LOCK_LINE_MAX];
+??? char type[4], namefmt[4], *p;
+??? char addr[64];
+??? char first_lkid[64];
+??? int rv, nodeid, root_list, recover_list, recover_locks_count, namelen;
+??? uint32_t flags;
+
+??? list_for_each_entry(ls, ls_rejoin, list) {
+??????? if (!ls->vg_name)
+??????????? continue;
+??????? snprintf(path, PATH_MAX, "/sys/kernel/debug/dlm/lvm_%s_all", 
ls->vg_name);
+??????? file = fopen(path, "r");
+??????? if (!file)
+??????????? continue;
+??????? while (fgets(line, LOCK_LINE_MAX, file)) {
+??????????? if (!strncmp(line, "rsb", 3)) {
+??? ??????????? rv = sscanf(line, "%s %s %d %s %u %d %d %u %u %s",
+??? ??????????? ??? ??? type,
+??? ??????????? ??? ??? addr,
+??? ??????????? ??? ??? &nodeid,
+??? ??????????? ??? ??? first_lkid,
+??? ??????????? ??? ??? &flags,
+??? ??????????? ??? ??? &root_list,
+??? ??????????? ??? ??? &recover_list,
+??? ??????????? ??? ??? &recover_locks_count,
+??? ??????????? ??? ??? &namelen,
+??? ??????????? ??? ??? namefmt);
+??????????????? if (rv != 10)
+??????????????????? goto fail;
+??????????????? p = strchr(line, '\n');
+??????????????? if (!p)
+??????????????????? goto fail;
+??????????????? *p = '\0';
+
+??????????????? if (strncmp(namefmt, "str", 3))
+??????????????????? continue;
+??????????????? p = strstr(line, namefmt);
+??????????????? if (!p)
+??????????????????? goto fail;
+??????????????? p += 4;
+
+??????????????? /*
+???????????????? * add resource
+???????????????? */
+??????????????? if (!(r = alloc_resource()))
+??????????????????? goto fail;
+??????????????? r->type = LD_RT_LV;
+??????????????? strcpy(r->name, p);
+??????????????? list_add(&r->list, &ls->resources);
+??????????? }
+??????? }
+??????? fclose(file);
+??? }
+??? return 0;
+fail:
+??? log_error("failed to process resources");
+??? fclose(file);
+??? return rv;
+}
+
+
 ?int lm_get_lockspaces_dlm(struct list_head *ls_rejoin)
 ?{
 ???? static const char closedir_err_msg[] = "lm_get_lockspace_dlm: 
closedir failed";
@@ -766,6 +839,8 @@ int lm_get_lockspaces_dlm(struct list_head *ls_rejoin)
 ???? ??? list_add_tail(&ls->list, ls_rejoin);
 ???? }

+??? lm_get_resources_dlm(ls_rejoin);
+
 ???? if (closedir(ls_dir))
 ???? ??? log_error(closedir_err_msg);
 ???? return 0;
diff --git a/daemons/lvmlockd/lvmlockd-internal.h 
b/daemons/lvmlockd/lvmlockd-internal.h
index ad32eb3a4..98ee63d84 100644
--- a/daemons/lvmlockd/lvmlockd-internal.h
+++ b/daemons/lvmlockd/lvmlockd-internal.h
@@ -365,6 +365,7 @@ void log_level(int level, const char *fmt, ...)? 
__attribute__((format(printf, 2
 ?#define log_warn(fmt, args...) log_level(LOG_WARNING, fmt, ##args)

 ?struct lockspace *alloc_lockspace(void);
+struct resource *alloc_resource(void);
 ?int lockspaces_empty(void);
 ?int last_string_from_args(char *args_in, char *last);
 ?int version_from_args(char *args, unsigned int *major, unsigned int 
*minor, unsigned int *patch);
-- 
2.35.3


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