When libmpathpersist notifies multipathd that a key has been registered,
cli_setprstatus() calls pr_register_active_paths() with a flag to let it
know that the paths are likely already registered, and it can skip
re-registering them, as long as the number of active paths matches the
number of registered keys. This shortcut can fail, causing multipathd to
not register needed paths, if either a path becomes usable and another
becomes unusable while libmpathpersist is running or if there already
were registered keys for I_T Nexus's that don't correspond to path
devices.
To make this shortcut work in cases like that, this commit adds a new
multipathd command "setprstatus map <map> pathlist <pathlist>", where
<pathlist> is a quoted, comma separated list of scsi path devices.
libmpathpersist will send out the list of paths it registered the key
on. pr_register_active_paths() will skip calling mpath_pr_event_handle()
for paths on that list.
In order to deal with the possiblity of a preempt occuring while
libmpathpersist was running, the code still needs to check that it has
the expected number of keys.
Fixes: f7d6cd17 ("multipathd: Fix race while registering PR key")
Signed-off-by: Benjamin Marzinski <[email protected]>
---
libmpathpersist/mpath_persist_int.c | 6 +--
libmpathpersist/mpath_updatepr.c | 48 +++++++++++++++++------
libmpathpersist/mpathpr.h | 4 +-
multipathd/callbacks.c | 1 +
multipathd/cli.c | 1 +
multipathd/cli.h | 2 +
multipathd/cli_handlers.c | 39 ++++++++++++++++--
multipathd/main.c | 61 +++++++++++++++++++----------
multipathd/main.h | 3 +-
multipathd/multipathd.8.in | 6 +++
10 files changed, 132 insertions(+), 39 deletions(-)
diff --git a/libmpathpersist/mpath_persist_int.c
b/libmpathpersist/mpath_persist_int.c
index 91c53419..14f7ba83 100644
--- a/libmpathpersist/mpath_persist_int.c
+++ b/libmpathpersist/mpath_persist_int.c
@@ -1001,12 +1001,12 @@ int do_mpath_persistent_reserve_out(vector curmp,
vector pathvec, int fd,
case MPATH_PROUT_REG_SA:
case MPATH_PROUT_REG_IGN_SA:
if (unregistering)
- update_prflag(mpp->alias, 0);
+ update_prflag(mpp, 0);
else
- update_prflag(mpp->alias, 1);
+ update_prflag(mpp, 1);
break;
case MPATH_PROUT_CLEAR_SA:
- update_prflag(mpp->alias, 0);
+ update_prflag(mpp, 0);
if (mpp->prkey_source == PRKEY_SOURCE_FILE)
update_prkey(mpp->alias, 0);
break;
diff --git a/libmpathpersist/mpath_updatepr.c b/libmpathpersist/mpath_updatepr.c
index bd8ed2be..bc9c79e2 100644
--- a/libmpathpersist/mpath_updatepr.c
+++ b/libmpathpersist/mpath_updatepr.c
@@ -20,8 +20,9 @@
#include "uxsock.h"
#include "mpathpr.h"
#include "structs.h"
+#include "strbuf.h"
-static char *do_pr(char *alias, char *str)
+static char *do_pr(char *alias, const char *str)
{
int fd;
char *reply;
@@ -51,24 +52,27 @@ static char *do_pr(char *alias, char *str)
return reply;
}
-static int do_update_pr(char *alias, char *cmd, char *key)
+static int do_update_pr(char *alias, char *cmd, const char *data)
{
- char str[256];
+ STRBUF_ON_STACK(buf);
char *reply = NULL;
int ret = -1;
- if (key)
- snprintf(str, sizeof(str), "%s map %s key %s", cmd, alias, key);
+ if (data)
+ print_strbuf(&buf, "%s map %s %s %s", cmd, alias,
+ strcmp(cmd, "setprkey") ? "pathlist" : "key",
+ data);
else
- snprintf(str, sizeof(str), "%s map %s", cmd, alias);
+ print_strbuf(&buf, "%s map %s", cmd, alias);
- reply = do_pr(alias, str);
+ reply = do_pr(alias, get_strbuf_str(&buf));
if (reply) {
if (strncmp(reply, "ok", 2) == 0)
ret = 0;
else
ret = -1;
- condlog(ret ? 0 : 4, "%s: message=%s reply=%s", alias, str,
reply);
+ condlog(ret ? 0 : 4, "%s: message=%s reply=%s", alias,
+ get_strbuf_str(&buf), reply);
}
free(reply);
@@ -106,9 +110,31 @@ int get_prhold(char *mapname)
return do_get_pr(mapname, "getprhold");
}
-int update_prflag(char *mapname, int set) {
- return do_update_pr(mapname, (set)? "setprstatus" : "unsetprstatus",
- NULL);
+int update_prflag(struct multipath *mpp, int set)
+{
+ STRBUF_ON_STACK(buf);
+ int i, j;
+ bool first = true;
+ struct pathgroup *pgp = NULL;
+ struct path *pp = NULL;
+
+ if (!set)
+ return do_update_pr(mpp->alias, "unsetprstatus", NULL);
+
+ append_strbuf_str(&buf, "\"");
+ vector_foreach_slot (mpp->pg, pgp, j) {
+ vector_foreach_slot (pgp->paths, pp, i) {
+ if (pp->state == PATH_UP || pp->state == PATH_GHOST) {
+ if (first) {
+ append_strbuf_str(&buf, pp->dev);
+ first = false;
+ } else
+ print_strbuf(&buf, " %s", pp->dev);
+ }
+ }
+ }
+ append_strbuf_str(&buf, "\"");
+ return do_update_pr(mpp->alias, "setprstatus", get_strbuf_str(&buf));
}
int update_prhold(char *mapname, bool set)
diff --git a/libmpathpersist/mpathpr.h b/libmpathpersist/mpathpr.h
index 99d6b82f..adbfc865 100644
--- a/libmpathpersist/mpathpr.h
+++ b/libmpathpersist/mpathpr.h
@@ -1,12 +1,14 @@
#ifndef MPATHPR_H_INCLUDED
#define MPATHPR_H_INCLUDED
+#include "structs.h"
+
/*
* This header file contains symbols that are only used by
* libmpathpersist internally.
*/
-int update_prflag(char *mapname, int set);
+int update_prflag(struct multipath *mpp, int set);
int update_prkey_flags(char *mapname, uint64_t prkey, uint8_t sa_flags);
int get_prflag(char *mapname);
int get_prhold(char *mapname);
diff --git a/multipathd/callbacks.c b/multipathd/callbacks.c
index b6b57f45..1129855b 100644
--- a/multipathd/callbacks.c
+++ b/multipathd/callbacks.c
@@ -59,6 +59,7 @@ void init_handler_callbacks(void)
set_unlocked_handler_callback(VRB_SHUTDOWN, HANDLER(cli_shutdown));
set_handler_callback(VRB_GETPRSTATUS | Q1_MAP,
HANDLER(cli_getprstatus));
set_handler_callback(VRB_SETPRSTATUS | Q1_MAP,
HANDLER(cli_setprstatus));
+ set_handler_callback(VRB_SETPRSTATUS | Q1_MAP | Q2_PATHLIST,
HANDLER(cli_setprstatus_list));
set_handler_callback(VRB_UNSETPRSTATUS | Q1_MAP,
HANDLER(cli_unsetprstatus));
set_handler_callback(VRB_FORCEQ | Q1_DAEMON,
HANDLER(cli_force_no_daemon_q));
set_handler_callback(VRB_RESTOREQ | Q1_DAEMON,
HANDLER(cli_restore_no_daemon_q));
diff --git a/multipathd/cli.c b/multipathd/cli.c
index d0e6cebc..0d679c86 100644
--- a/multipathd/cli.c
+++ b/multipathd/cli.c
@@ -227,6 +227,7 @@ load_keys (void)
r += add_key(keys, "getprhold", VRB_GETPRHOLD, 0);
r += add_key(keys, "setprhold", VRB_SETPRHOLD, 0);
r += add_key(keys, "unsetprhold", VRB_UNSETPRHOLD, 0);
+ r += add_key(keys, "pathlist", KEY_PATHLIST, 1);
if (r) {
free_keys(keys);
diff --git a/multipathd/cli.h b/multipathd/cli.h
index 5a943a45..3e607389 100644
--- a/multipathd/cli.h
+++ b/multipathd/cli.h
@@ -62,6 +62,7 @@ enum {
KEY_LOCAL = 81,
KEY_GROUP = 82,
KEY_KEY = 83,
+ KEY_PATHLIST = 84,
};
/*
@@ -94,6 +95,7 @@ enum {
Q2_LOCAL = KEY_LOCAL << 16,
Q2_GROUP = KEY_GROUP << 16,
Q2_KEY = KEY_KEY << 16,
+ Q2_PATHLIST = KEY_PATHLIST << 16,
/* byte 3: qualifier 3 */
Q3_FMT = KEY_FMT << 24,
diff --git a/multipathd/cli_handlers.c b/multipathd/cli_handlers.c
index 2812d01e..5770dcec 100644
--- a/multipathd/cli_handlers.c
+++ b/multipathd/cli_handlers.c
@@ -31,6 +31,7 @@
#include "foreign.h"
#include "strbuf.h"
#include "cli_handlers.h"
+#include <ctype.h>
static struct path *
find_path_by_str(const struct vector_s *pathvec, const char *str,
@@ -1276,8 +1277,8 @@ cli_getprstatus (void * v, struct strbuf *reply, void *
data)
return 0;
}
-static int
-cli_setprstatus(void * v, struct strbuf *reply, void * data)
+static int do_setprstatus(void * v, struct strbuf *reply, void * data,
+ const struct vector_s *registered_paths)
{
struct multipath * mpp;
struct vectors * vecs = (struct vectors *)data;
@@ -1291,7 +1292,7 @@ cli_setprstatus(void * v, struct strbuf *reply, void *
data)
if (mpp->prflag != PR_SET) {
set_pr(mpp);
- pr_register_active_paths(mpp, true);
+ pr_register_active_paths(mpp, registered_paths);
if (mpp->prflag == PR_SET)
condlog(2, "%s: prflag set", param);
else
@@ -1302,6 +1303,38 @@ cli_setprstatus(void * v, struct strbuf *reply, void *
data)
return 0;
}
+static int
+cli_setprstatus(void * v, struct strbuf *reply, void * data)
+{
+ return do_setprstatus(v, reply, data, NULL);
+}
+
+static int
+cli_setprstatus_list(void * v, struct strbuf *reply, void * data)
+{
+ int r;
+ struct vector_s registered_paths = { .allocated = 0 };
+ char *ptr = get_keyparam(v, KEY_PATHLIST);
+
+ while (isspace(*ptr))
+ ptr++;
+ while (*ptr) {
+ if (!vector_alloc_slot(®istered_paths)) {
+ r = -ENOMEM;
+ goto out;
+ }
+ vector_set_slot(®istered_paths, ptr);
+ while (*ptr && !isspace(*ptr))
+ ptr++;
+ while (isspace(*ptr))
+ *ptr++ = '\0';
+ }
+ r = do_setprstatus(v, reply, data, ®istered_paths);
+out:
+ vector_reset(®istered_paths);
+ return r;
+}
+
static int
cli_unsetprstatus(void * v, struct strbuf *reply, void * data)
{
diff --git a/multipathd/main.c b/multipathd/main.c
index a7650639..2cd5c952 100644
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -630,28 +630,49 @@ flush_map_nopaths(struct multipath *mpp, struct vectors
*vecs) {
return true;
}
-void pr_register_active_paths(struct multipath *mpp, bool check_nr_active)
+/*
+ * If reg_paths in non-NULL, it is a vector of paths that libmpathpersist
+ * registered. If the number of registered keys is smaller than the number
+ * of registered paths, then likely a preempt that occurred while
+ * libmpathpersist was registering the key. As long as there are still some
+ * registered keys, treat the preempt as happening first, and make sure to
+ * register keys on all the paths. If the number of registered keys is at
+ * least as large as the number of registered paths, then no preempt happened,
+ * and multipathd does not need to re-register the paths that libmpathpersist
+ * handled
+ */
+void pr_register_active_paths(struct multipath *mpp,
+ const struct vector_s *reg_paths)
{
- unsigned int i, j, nr_keys = 0;
- unsigned int nr_active = 0;
+ unsigned int i, j, k, nr_keys = 0;
+ unsigned int wanted_nr = VECTOR_SIZE(reg_paths);
struct path *pp;
struct pathgroup *pgp;
-
- if (check_nr_active) {
- nr_active = count_active_paths(mpp);
- if (!nr_active)
- return;
- }
+ char *pathname;
vector_foreach_slot (mpp->pg, pgp, i) {
vector_foreach_slot (pgp->paths, pp, j) {
if (mpp->prflag == PR_UNSET)
return;
- if (pp->state == PATH_UP || pp->state == PATH_GHOST) {
- nr_keys = mpath_pr_event_handle(pp, nr_keys,
nr_active);
- if (check_nr_active && nr_keys == nr_active)
- return;
+ if (pp->state != PATH_UP && pp->state != PATH_GHOST)
+ continue;
+ if (wanted_nr && nr_keys) {
+ vector_foreach_slot(reg_paths, pathname, k) {
+ if (strcmp(pp->dev, pathname) == 0 ||
+ strcmp(pp->dev_t, pathname) == 0) {
+ goto skip;
+ }
+ }
+ }
+ nr_keys = mpath_pr_event_handle(pp, nr_keys, wanted_nr);
+ if (nr_keys && nr_keys < wanted_nr) {
+ /*
+ * Incorrect number of registered keys. Need
+ * to register all devices
+ */
+ wanted_nr = 0;
}
+skip:
}
}
}
@@ -739,7 +760,7 @@ fail:
sync_map_state(mpp, false);
- pr_register_active_paths(mpp, false);
+ pr_register_active_paths(mpp, NULL);
if (VECTOR_SIZE(offline_paths) != 0)
handle_orphaned_offline_paths(offline_paths);
@@ -1413,7 +1434,7 @@ rescan:
if (retries >= 0) {
if ((mpp->prflag == PR_SET && prflag != PR_SET) || start_waiter)
- pr_register_active_paths(mpp, false);
+ pr_register_active_paths(mpp, NULL);
condlog(2, "%s [%s]: path added to devmap %s",
pp->dev, pp->dev_t, mpp->alias);
return 0;
@@ -2658,7 +2679,7 @@ update_path_state (struct vectors * vecs, struct path *
pp)
"reservation registration", pp->dev);
mpath_pr_event_handle(pp, 0, 0);
if (pp->mpp->prflag == PR_SET && prflag != PR_SET)
- pr_register_active_paths(pp->mpp, false);
+ pr_register_active_paths(pp->mpp, NULL);
}
/*
@@ -3319,7 +3340,7 @@ configure (struct vectors * vecs, enum force_reload_types
reload_type)
vector_foreach_slot(mpvec, mpp, i){
if (remember_wwid(mpp->wwid) == 1)
trigger_paths_udev_change(mpp, true);
- pr_register_active_paths(mpp, false);
+ pr_register_active_paths(mpp, NULL);
}
/*
@@ -4370,8 +4391,8 @@ static int update_map_pr(struct multipath *mpp, struct
path *pp, unsigned int *n
*
* nr_keys_wanted: Only used if nr_keys_needed is 0, so we don't know how
* many keys we currently have. If nr_keys_wanted in non-zero and the
- * number of keys found by the initial call to update_map_pr() matches it,
- * exit early, since we have all the keys we are expecting.
+ * number of keys found by the initial call to update_map_pr() is at least
+ * as large as it, exit early, since we have all the keys we are expecting.
*
* The function returns the number of keys that are registered or 0 if
* it's unknown.
@@ -4394,7 +4415,7 @@ mpath_pr_event_handle(struct path *pp, unsigned int
nr_keys_needed,
nr_keys_needed = 1;
if (update_map_pr(mpp, pp, &nr_keys_needed) != MPATH_PR_SUCCESS)
return 0;
- if (nr_keys_wanted && nr_keys_wanted == nr_keys_needed)
+ if (nr_keys_wanted && nr_keys_wanted <= nr_keys_needed)
return nr_keys_needed;
}
diff --git a/multipathd/main.h b/multipathd/main.h
index 6d60ee81..85b533cd 100644
--- a/multipathd/main.h
+++ b/multipathd/main.h
@@ -54,5 +54,6 @@ int resize_map(struct multipath *mpp, unsigned long long size,
struct vectors *vecs);
void set_pr(struct multipath *mpp);
void unset_pr(struct multipath *mpp);
-void pr_register_active_paths(struct multipath *mpp, bool check_active_nr);
+void pr_register_active_paths(struct multipath *mpp,
+ const struct vector_s *registered_paths);
#endif /* MAIN_H_INCLUDED */
diff --git a/multipathd/multipathd.8.in b/multipathd/multipathd.8.in
index 7ffb8d4c..38a243e3 100644
--- a/multipathd/multipathd.8.in
+++ b/multipathd/multipathd.8.in
@@ -348,6 +348,12 @@ Restores configured queue_without_daemon mode.
Enable persistent reservation management on $map.
.
.TP
+.B setprstatus map|multipath $map pathlist $pathlist
+Enable persistent reservation management on $map, and notify multipathd of
+the paths that have been registered, so it doesn't attempt to re-register
+them.
+.
+.TP
.B unsetprstatus map|multipath $map
Disable persistent reservation management on $map.
.
--
2.50.1
