This makes the timeout for "find_multipaths smart" configurable.
If the timeout has a negative value (default), it's applied only
to "known" hardware which is either in the hwtable or in a "device" section in
multipath.conf. For typical non-multipath hardware, which is not in the
hwtable, a short timeout of 1s is used, so that boot delays caused by
pointlessly waiting e.g. for SATA devices will be minimal.
It's expected that a "reasonable" timeout value depends less on the storage
hardware itself but on other properties of the data center such as network
latencies or distances. find_multipaths_timeout is therefore just a "defaults"
section setting.
Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
---
libmultipath/config.h | 1 +
libmultipath/defaults.h | 2 ++
libmultipath/dict.c | 6 ++++++
libmultipath/propsel.c | 25 +++++++++++++++++++++++++
libmultipath/propsel.h | 1 +
libmultipath/structs.h | 1 +
multipath/multipath.conf.5 | 18 ++++++++++++++++++
7 files changed, 54 insertions(+)
diff --git a/libmultipath/config.h b/libmultipath/config.h
index c71d972..6e69a37 100644
--- a/libmultipath/config.h
+++ b/libmultipath/config.h
@@ -174,6 +174,7 @@ struct config {
int remove_retries;
int max_sectors_kb;
int ghost_delay;
+ int find_multipaths_timeout;
unsigned int version[3];
char * multipath_dir;
diff --git a/libmultipath/defaults.h b/libmultipath/defaults.h
index 19ad2bf..d7b87b4 100644
--- a/libmultipath/defaults.h
+++ b/libmultipath/defaults.h
@@ -41,6 +41,8 @@
#define DEFAULT_DISABLE_CHANGED_WWIDS 1
#define DEFAULT_MAX_SECTORS_KB MAX_SECTORS_KB_UNDEF
#define DEFAULT_GHOST_DELAY GHOST_DELAY_OFF
+#define DEFAULT_FIND_MULTIPATHS_TIMEOUT -10
+#define DEFAULT_UNKNOWN_FIND_MULTIPATHS_TIMEOUT 1
#define DEFAULT_CHECKINT 5
#define MAX_CHECKINT(a) (a << 2)
diff --git a/libmultipath/dict.c b/libmultipath/dict.c
index e695fdc..4be808d 100644
--- a/libmultipath/dict.c
+++ b/libmultipath/dict.c
@@ -485,6 +485,10 @@ declare_hw_snprint(max_sectors_kb, print_nonzero)
declare_mp_handler(max_sectors_kb, set_int)
declare_mp_snprint(max_sectors_kb, print_nonzero)
+declare_def_handler(find_multipaths_timeout, set_int)
+declare_def_snprint_defint(find_multipaths_timeout, print_int,
+ DEFAULT_FIND_MULTIPATHS_TIMEOUT)
+
static int
def_config_dir_handler(struct config *conf, vector strvec)
{
@@ -1519,6 +1523,8 @@ init_keywords(vector keywords)
install_keyword("remove_retries", &def_remove_retries_handler, &snprint_def_remove_retries);
install_keyword("max_sectors_kb", &def_max_sectors_kb_handler, &snprint_def_max_sectors_kb);
install_keyword("ghost_delay", &def_ghost_delay_handler, &snprint_def_ghost_delay);
+ install_keyword("find_multipaths_timeout", &def_find_multipaths_timeout_handler,
+ &snprint_def_find_multipaths_timeout);
__deprecated install_keyword("default_selector", &def_selector_handler, NULL);
__deprecated install_keyword("default_path_grouping_policy", &def_pgpolicy_handler, NULL);
__deprecated install_keyword("default_uid_attribute", &def_uid_attribute_handler, NULL);
diff --git a/libmultipath/propsel.c b/libmultipath/propsel.c
index 93974a4..70fb997 100644
--- a/libmultipath/propsel.c
+++ b/libmultipath/propsel.c
@@ -912,3 +912,28 @@ out:
condlog(3, "%s: ghost_delay = %s %s", mp->alias, buff, origin);
return 0;
}
+
+int select_find_multipaths_timeout(struct config *conf, struct path *pp)
+{
+ char *origin;
+
+ pp_set_conf(find_multipaths_timeout);
+ pp_set_default(find_multipaths_timeout,
+ DEFAULT_FIND_MULTIPATHS_TIMEOUT);
+out:
+ /*
+ * If configured value is negative, and this "unkown" hardware
+ * (no hwentry), use very small timeout to avoid delays.
+ */
+ if (pp->find_multipaths_timeout < 0) {
+ pp->find_multipaths_timeout = - pp->find_multipaths_timeout;
+ if (!pp->hwe) {
+ pp->find_multipaths_timeout =
+ DEFAULT_UNKNOWN_FIND_MULTIPATHS_TIMEOUT;
+ origin = "(default for unkown hardware)";
+ }
+ }
+ condlog(3, "%s: timeout for find_multipaths \"smart\" = %ds %s",
+ pp->dev, pp->find_multipaths_timeout, origin);
+ return 0;
+}
diff --git a/libmultipath/propsel.h b/libmultipath/propsel.h
index 136f906..b6475d0 100644
--- a/libmultipath/propsel.h
+++ b/libmultipath/propsel.h
@@ -8,6 +8,7 @@ int select_hwhandler (struct config *conf, struct multipath * mp);
int select_checker(struct config *conf, struct path *pp);
int select_getuid (struct config *conf, struct path * pp);
int select_prio (struct config *conf, struct path * pp);
+int select_find_multipaths_timeout(struct config *conf, struct path * pp);
int select_no_path_retry(struct config *conf, struct multipath *mp);
int select_flush_on_last_del(struct config *conf, struct multipath *mp);
int select_minio(struct config *conf, struct multipath *mp);
diff --git a/libmultipath/structs.h b/libmultipath/structs.h
index 1d3a34f..eb6a178 100644
--- a/libmultipath/structs.h
+++ b/libmultipath/structs.h
@@ -281,6 +281,7 @@ struct path {
int io_err_disable_reinstate;
int io_err_pathfail_cnt;
int io_err_pathfail_starttime;
+ int find_multipaths_timeout;
/* configlet pointers */
struct hwentry * hwe;
struct gen_path generic_path;
diff --git a/multipath/multipath.conf.5 b/multipath/multipath.conf.5
index 6965dac..94c419a 100644
--- a/multipath/multipath.conf.5
+++ b/multipath/multipath.conf.5
@@ -983,6 +983,24 @@ The default is: \fBstrict\fR
.
.
.TP
+.B find_multipaths_timeout
+Timeout, in seconds, to wait for additional paths after detecting the first
+one, if \fIfind_multipaths
+"smart"\fR (see above) is set. If the value is \fBpositive\fR, this timeout is used for all
+unkown, non-blacklisted devices encountered. If the value is \fBnegative\fR
+(recommended), it's only
+applied to "known" devices that have an entry in multipath's hardware table,
+either in the built-in table or in a \fIdevice\fR section; other ("unknown") devices will
+use a timeout of only 1 second to avoid booting delays. The value 0 means
+"use the built-in default". If \fIfind_multipath\fR has a value
+other than \fIsmart\fR, this option has no effect.
+.RS
+.TP
+The default is: \fB-10\fR (10s for known and 1s for unknown hardware)
+.RE
+.
+.
+.TP
.B uxsock_timeout
CLI receive timeout in milliseconds. For larger systems CLI commands
might timeout before the multipathd lock is released and the CLI command
--
2.16.1
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