[dm-devel] [PATCH 04/19] Revert "multipath-tools: discard san_path_err_XXX feature"

Martin Wilck mwilck at suse.com
Tue Dec 18 23:19:16 UTC 2018


This reverts commit 9cf6a48f18a291982af34b4fb0110654b94e591c.
We removed this functionality prematurely. I am not convinced
that the "marginal_path" code really replaces it. Let customers
evaluate the different options, and vote with their feet.

Cc: Guan Junxiong <guanjunxiong at huawei.com>
Cc: M Muneendra Kumar <mmandala at brocade.com>
Signed-off-by: Martin Wilck <mwilck at suse.com>
---
 libmultipath/config.c      |  3 ++
 libmultipath/config.h      |  9 ++++
 libmultipath/configure.c   |  3 ++
 libmultipath/dict.c        | 39 ++++++++++++++++++
 libmultipath/propsel.c     | 53 ++++++++++++++++++++++++
 libmultipath/propsel.h     |  3 ++
 libmultipath/structs.h     |  7 ++++
 multipath/multipath.conf.5 | 57 ++++++++++++++++++++++++++
 multipathd/main.c          | 84 ++++++++++++++++++++++++++++++++++++++
 9 files changed, 258 insertions(+)

diff --git a/libmultipath/config.c b/libmultipath/config.c
index 5af7af58..24d71aed 100644
--- a/libmultipath/config.c
+++ b/libmultipath/config.c
@@ -369,6 +369,9 @@ merge_hwe (struct hwentry * dst, struct hwentry * src)
 	merge_num(max_sectors_kb);
 	merge_num(ghost_delay);
 	merge_num(all_tg_pt);
+	merge_num(san_path_err_threshold);
+	merge_num(san_path_err_forget_rate);
+	merge_num(san_path_err_recovery_time);
 
 	snprintf(id, sizeof(id), "%s/%s", dst->vendor, dst->product);
 	reconcile_features_with_options(id, &dst->features,
diff --git a/libmultipath/config.h b/libmultipath/config.h
index 7d0cd9a6..b938c26c 100644
--- a/libmultipath/config.h
+++ b/libmultipath/config.h
@@ -76,6 +76,9 @@ struct hwentry {
 	int deferred_remove;
 	int delay_watch_checks;
 	int delay_wait_checks;
+	int san_path_err_threshold;
+	int san_path_err_forget_rate;
+	int san_path_err_recovery_time;
 	int marginal_path_err_sample_time;
 	int marginal_path_err_rate_threshold;
 	int marginal_path_err_recheck_gap_time;
@@ -112,6 +115,9 @@ struct mpentry {
 	int deferred_remove;
 	int delay_watch_checks;
 	int delay_wait_checks;
+	int san_path_err_threshold;
+	int san_path_err_forget_rate;
+	int san_path_err_recovery_time;
 	int marginal_path_err_sample_time;
 	int marginal_path_err_rate_threshold;
 	int marginal_path_err_recheck_gap_time;
@@ -162,6 +168,9 @@ struct config {
 	int processed_main_config;
 	int delay_watch_checks;
 	int delay_wait_checks;
+	int san_path_err_threshold;
+	int san_path_err_forget_rate;
+	int san_path_err_recovery_time;
 	int marginal_path_err_sample_time;
 	int marginal_path_err_rate_threshold;
 	int marginal_path_err_recheck_gap_time;
diff --git a/libmultipath/configure.c b/libmultipath/configure.c
index 84ae5f56..60a98873 100644
--- a/libmultipath/configure.c
+++ b/libmultipath/configure.c
@@ -309,6 +309,9 @@ int setup_map(struct multipath *mpp, char *params, int params_size,
 	select_deferred_remove(conf, mpp);
 	select_delay_watch_checks(conf, mpp);
 	select_delay_wait_checks(conf, mpp);
+	select_san_path_err_threshold(conf, mpp);
+	select_san_path_err_forget_rate(conf, mpp);
+	select_san_path_err_recovery_time(conf, mpp);
 	select_marginal_path_err_sample_time(conf, mpp);
 	select_marginal_path_err_rate_threshold(conf, mpp);
 	select_marginal_path_err_recheck_gap_time(conf, mpp);
diff --git a/libmultipath/dict.c b/libmultipath/dict.c
index a81c051f..fd29abca 100644
--- a/libmultipath/dict.c
+++ b/libmultipath/dict.c
@@ -1217,6 +1217,33 @@ declare_hw_handler(delay_wait_checks, set_off_int_undef)
 declare_hw_snprint(delay_wait_checks, print_off_int_undef)
 declare_mp_handler(delay_wait_checks, set_off_int_undef)
 declare_mp_snprint(delay_wait_checks, print_off_int_undef)
+declare_def_handler(san_path_err_threshold, set_off_int_undef)
+declare_def_snprint_defint(san_path_err_threshold, print_off_int_undef,
+			   DEFAULT_ERR_CHECKS)
+declare_ovr_handler(san_path_err_threshold, set_off_int_undef)
+declare_ovr_snprint(san_path_err_threshold, print_off_int_undef)
+declare_hw_handler(san_path_err_threshold, set_off_int_undef)
+declare_hw_snprint(san_path_err_threshold, print_off_int_undef)
+declare_mp_handler(san_path_err_threshold, set_off_int_undef)
+declare_mp_snprint(san_path_err_threshold, print_off_int_undef)
+declare_def_handler(san_path_err_forget_rate, set_off_int_undef)
+declare_def_snprint_defint(san_path_err_forget_rate, print_off_int_undef,
+			   DEFAULT_ERR_CHECKS)
+declare_ovr_handler(san_path_err_forget_rate, set_off_int_undef)
+declare_ovr_snprint(san_path_err_forget_rate, print_off_int_undef)
+declare_hw_handler(san_path_err_forget_rate, set_off_int_undef)
+declare_hw_snprint(san_path_err_forget_rate, print_off_int_undef)
+declare_mp_handler(san_path_err_forget_rate, set_off_int_undef)
+declare_mp_snprint(san_path_err_forget_rate, print_off_int_undef)
+declare_def_handler(san_path_err_recovery_time, set_off_int_undef)
+declare_def_snprint_defint(san_path_err_recovery_time, print_off_int_undef,
+			   DEFAULT_ERR_CHECKS)
+declare_ovr_handler(san_path_err_recovery_time, set_off_int_undef)
+declare_ovr_snprint(san_path_err_recovery_time, print_off_int_undef)
+declare_hw_handler(san_path_err_recovery_time, set_off_int_undef)
+declare_hw_snprint(san_path_err_recovery_time, print_off_int_undef)
+declare_mp_handler(san_path_err_recovery_time, set_off_int_undef)
+declare_mp_snprint(san_path_err_recovery_time, print_off_int_undef)
 declare_def_handler(marginal_path_err_sample_time, set_off_int_undef)
 declare_def_snprint_defint(marginal_path_err_sample_time, print_off_int_undef,
 			   DEFAULT_ERR_CHECKS)
@@ -1620,6 +1647,9 @@ init_keywords(vector keywords)
 	install_keyword("config_dir", &def_config_dir_handler, &snprint_def_config_dir);
 	install_keyword("delay_watch_checks", &def_delay_watch_checks_handler, &snprint_def_delay_watch_checks);
 	install_keyword("delay_wait_checks", &def_delay_wait_checks_handler, &snprint_def_delay_wait_checks);
+	install_keyword("san_path_err_threshold", &def_san_path_err_threshold_handler, &snprint_def_san_path_err_threshold);
+	install_keyword("san_path_err_forget_rate", &def_san_path_err_forget_rate_handler, &snprint_def_san_path_err_forget_rate);
+	install_keyword("san_path_err_recovery_time", &def_san_path_err_recovery_time_handler, &snprint_def_san_path_err_recovery_time);
 	install_keyword("marginal_path_err_sample_time", &def_marginal_path_err_sample_time_handler, &snprint_def_marginal_path_err_sample_time);
 	install_keyword("marginal_path_err_rate_threshold", &def_marginal_path_err_rate_threshold_handler, &snprint_def_marginal_path_err_rate_threshold);
 	install_keyword("marginal_path_err_recheck_gap_time", &def_marginal_path_err_recheck_gap_time_handler, &snprint_def_marginal_path_err_recheck_gap_time);
@@ -1714,6 +1744,9 @@ init_keywords(vector keywords)
 	install_keyword("deferred_remove", &hw_deferred_remove_handler, &snprint_hw_deferred_remove);
 	install_keyword("delay_watch_checks", &hw_delay_watch_checks_handler, &snprint_hw_delay_watch_checks);
 	install_keyword("delay_wait_checks", &hw_delay_wait_checks_handler, &snprint_hw_delay_wait_checks);
+	install_keyword("san_path_err_threshold", &hw_san_path_err_threshold_handler, &snprint_hw_san_path_err_threshold);
+	install_keyword("san_path_err_forget_rate", &hw_san_path_err_forget_rate_handler, &snprint_hw_san_path_err_forget_rate);
+	install_keyword("san_path_err_recovery_time", &hw_san_path_err_recovery_time_handler, &snprint_hw_san_path_err_recovery_time);
 	install_keyword("marginal_path_err_sample_time", &hw_marginal_path_err_sample_time_handler, &snprint_hw_marginal_path_err_sample_time);
 	install_keyword("marginal_path_err_rate_threshold", &hw_marginal_path_err_rate_threshold_handler, &snprint_hw_marginal_path_err_rate_threshold);
 	install_keyword("marginal_path_err_recheck_gap_time", &hw_marginal_path_err_recheck_gap_time_handler, &snprint_hw_marginal_path_err_recheck_gap_time);
@@ -1750,6 +1783,9 @@ init_keywords(vector keywords)
 	install_keyword("deferred_remove", &ovr_deferred_remove_handler, &snprint_ovr_deferred_remove);
 	install_keyword("delay_watch_checks", &ovr_delay_watch_checks_handler, &snprint_ovr_delay_watch_checks);
 	install_keyword("delay_wait_checks", &ovr_delay_wait_checks_handler, &snprint_ovr_delay_wait_checks);
+	install_keyword("san_path_err_threshold", &ovr_san_path_err_threshold_handler, &snprint_ovr_san_path_err_threshold);
+	install_keyword("san_path_err_forget_rate", &ovr_san_path_err_forget_rate_handler, &snprint_ovr_san_path_err_forget_rate);
+	install_keyword("san_path_err_recovery_time", &ovr_san_path_err_recovery_time_handler, &snprint_ovr_san_path_err_recovery_time);
 	install_keyword("marginal_path_err_sample_time", &ovr_marginal_path_err_sample_time_handler, &snprint_ovr_marginal_path_err_sample_time);
 	install_keyword("marginal_path_err_rate_threshold", &ovr_marginal_path_err_rate_threshold_handler, &snprint_ovr_marginal_path_err_rate_threshold);
 	install_keyword("marginal_path_err_recheck_gap_time", &ovr_marginal_path_err_recheck_gap_time_handler, &snprint_ovr_marginal_path_err_recheck_gap_time);
@@ -1785,6 +1821,9 @@ init_keywords(vector keywords)
 	install_keyword("deferred_remove", &mp_deferred_remove_handler, &snprint_mp_deferred_remove);
 	install_keyword("delay_watch_checks", &mp_delay_watch_checks_handler, &snprint_mp_delay_watch_checks);
 	install_keyword("delay_wait_checks", &mp_delay_wait_checks_handler, &snprint_mp_delay_wait_checks);
+	install_keyword("san_path_err_threshold", &mp_san_path_err_threshold_handler, &snprint_mp_san_path_err_threshold);
+	install_keyword("san_path_err_forget_rate", &mp_san_path_err_forget_rate_handler, &snprint_mp_san_path_err_forget_rate);
+	install_keyword("san_path_err_recovery_time", &mp_san_path_err_recovery_time_handler, &snprint_mp_san_path_err_recovery_time);
 	install_keyword("marginal_path_err_sample_time", &mp_marginal_path_err_sample_time_handler, &snprint_mp_marginal_path_err_sample_time);
 	install_keyword("marginal_path_err_rate_threshold", &mp_marginal_path_err_rate_threshold_handler, &snprint_mp_marginal_path_err_rate_threshold);
 	install_keyword("marginal_path_err_recheck_gap_time", &mp_marginal_path_err_recheck_gap_time_handler, &snprint_mp_marginal_path_err_recheck_gap_time);
diff --git a/libmultipath/propsel.c b/libmultipath/propsel.c
index 7b19fed0..a4d114c0 100644
--- a/libmultipath/propsel.c
+++ b/libmultipath/propsel.c
@@ -879,6 +879,59 @@ out:
 
 }
 
+int select_san_path_err_threshold(struct config *conf, struct multipath *mp)
+{
+	const char *origin;
+	char buff[12];
+
+	mp_set_mpe(san_path_err_threshold);
+	mp_set_ovr(san_path_err_threshold);
+	mp_set_hwe(san_path_err_threshold);
+	mp_set_conf(san_path_err_threshold);
+	mp_set_default(san_path_err_threshold, DEFAULT_ERR_CHECKS);
+out:
+	print_off_int_undef(buff, 12, mp->san_path_err_threshold);
+	condlog(3, "%s: san_path_err_threshold = %s %s", mp->alias, buff,
+		origin);
+	return 0;
+}
+
+int select_san_path_err_forget_rate(struct config *conf, struct multipath *mp)
+{
+	const char *origin;
+	char buff[12];
+
+	mp_set_mpe(san_path_err_forget_rate);
+	mp_set_ovr(san_path_err_forget_rate);
+	mp_set_hwe(san_path_err_forget_rate);
+	mp_set_conf(san_path_err_forget_rate);
+	mp_set_default(san_path_err_forget_rate, DEFAULT_ERR_CHECKS);
+out:
+	print_off_int_undef(buff, 12, mp->san_path_err_forget_rate);
+	condlog(3, "%s: san_path_err_forget_rate = %s %s", mp->alias,
+		buff, origin);
+	return 0;
+
+}
+
+int select_san_path_err_recovery_time(struct config *conf, struct multipath *mp)
+{
+	const char *origin;
+	char buff[12];
+
+	mp_set_mpe(san_path_err_recovery_time);
+	mp_set_ovr(san_path_err_recovery_time);
+	mp_set_hwe(san_path_err_recovery_time);
+	mp_set_conf(san_path_err_recovery_time);
+	mp_set_default(san_path_err_recovery_time, DEFAULT_ERR_CHECKS);
+out:
+	print_off_int_undef(buff, 12, mp->san_path_err_recovery_time);
+	condlog(3, "%s: san_path_err_recovery_time = %s %s", mp->alias,
+		buff, origin);
+	return 0;
+
+}
+
 int select_marginal_path_err_sample_time(struct config *conf, struct multipath *mp)
 {
 	const char *origin;
diff --git a/libmultipath/propsel.h b/libmultipath/propsel.h
index ae99b927..b352c16a 100644
--- a/libmultipath/propsel.h
+++ b/libmultipath/propsel.h
@@ -26,6 +26,9 @@ int select_delay_watch_checks (struct config *conf, struct multipath * mp);
 int select_delay_wait_checks (struct config *conf, struct multipath * mp);
 int select_skip_kpartx (struct config *conf, struct multipath * mp);
 int select_max_sectors_kb (struct config *conf, struct multipath * mp);
+int select_san_path_err_forget_rate(struct config *conf, struct multipath *mp);
+int select_san_path_err_threshold(struct config *conf, struct multipath *mp);
+int select_san_path_err_recovery_time(struct config *conf, struct multipath *mp);
 int select_marginal_path_err_sample_time(struct config *conf, struct multipath *mp);
 int select_marginal_path_err_rate_threshold(struct config *conf, struct multipath *mp);
 int select_marginal_path_err_recheck_gap_time(struct config *conf, struct multipath *mp);
diff --git a/libmultipath/structs.h b/libmultipath/structs.h
index d8961164..96df8c8a 100644
--- a/libmultipath/structs.h
+++ b/libmultipath/structs.h
@@ -280,6 +280,10 @@ struct path {
 	int initialized;
 	int retriggers;
 	int wwid_changed;
+	unsigned int path_failures;
+	time_t dis_reinstate_time;
+	int disable_reinstate;
+	int san_path_err_forget_rate;
 	time_t io_err_dis_reinstate_time;
 	int io_err_disable_reinstate;
 	int io_err_pathfail_cnt;
@@ -318,6 +322,9 @@ struct multipath {
 	int deferred_remove;
 	int delay_watch_checks;
 	int delay_wait_checks;
+	int san_path_err_threshold;
+	int san_path_err_forget_rate;
+	int san_path_err_recovery_time;
 	int marginal_path_err_sample_time;
 	int marginal_path_err_rate_threshold;
 	int marginal_path_err_recheck_gap_time;
diff --git a/multipath/multipath.conf.5 b/multipath/multipath.conf.5
index 68119baa..35e6d37c 100644
--- a/multipath/multipath.conf.5
+++ b/multipath/multipath.conf.5
@@ -891,6 +891,45 @@ The default is: \fB/etc/multipath/conf.d/\fR
 .
 .
 .TP
+.B san_path_err_threshold
+If set to a value greater than 0, multipathd will watch paths and check how many
+times a path has been failed due to errors.If the number of failures on a particular
+path is greater then the san_path_err_threshold then the path will not  reinstante
+till san_path_err_recovery_time.These path failures should occur within a
+san_path_err_forget_rate checks, if not we will consider the path is good enough
+to reinstantate.
+.RS
+.TP
+The default is: \fBno\fR
+.RE
+.
+.
+.TP
+.B san_path_err_forget_rate
+If set to a value greater than 0, multipathd will check whether the path failures
+has exceeded  the san_path_err_threshold within this many checks i.e
+san_path_err_forget_rate . If so we will not reinstante the path till
+san_path_err_recovery_time.
+.RS
+.TP
+The default is: \fBno\fR
+.RE
+.
+.
+.TP
+.B san_path_err_recovery_time
+If set to a value greater than 0, multipathd will make sure that when path failures
+has exceeded the san_path_err_threshold within san_path_err_forget_rate then the path
+will be placed in failed state for san_path_err_recovery_time duration.Once san_path_err_recovery_time
+has timeout  we will reinstante the failed path .
+san_path_err_recovery_time value should be in secs.
+.RS
+.TP
+The default is: \fBno\fR
+.RE
+.
+.
+.TP
 .B marginal_path_double_failed_time
 One of the four parameters of supporting path check based on accounting IO
 error such as intermittent error. When a path failed event occurs twice in
@@ -1297,6 +1336,12 @@ section:
 .TP
 .B deferred_remove
 .TP
+.B san_path_err_threshold
+.TP
+.B san_path_err_forget_rate
+.TP
+.B san_path_err_recovery_time
+.TP
 .B marginal_path_err_sample_time
 .TP
 .B marginal_path_err_rate_threshold
@@ -1448,6 +1493,12 @@ section:
 .TP
 .B deferred_remove
 .TP
+.B san_path_err_threshold
+.TP
+.B san_path_err_forget_rate
+.TP
+.B san_path_err_recovery_time
+.TP
 .B marginal_path_err_sample_time
 .TP
 .B marginal_path_err_rate_threshold
@@ -1524,6 +1575,12 @@ the values are taken from the \fIdevices\fR or \fIdefaults\fR sections:
 .TP
 .B deferred_remove
 .TP
+.B san_path_err_threshold
+.TP
+.B san_path_err_forget_rate
+.TP
+.B san_path_err_recovery_time
+.TP
 .B marginal_path_err_sample_time
 .TP
 .B marginal_path_err_rate_threshold
diff --git a/multipathd/main.c b/multipathd/main.c
index 99145293..57bb7143 100644
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -1833,6 +1833,84 @@ int update_path_groups(struct multipath *mpp, struct vectors *vecs, int refresh)
 	return 0;
 }
 
+static int check_path_reinstate_state(struct path * pp) {
+	struct timespec curr_time;
+	if (!((pp->mpp->san_path_err_threshold > 0) &&
+				(pp->mpp->san_path_err_forget_rate > 0) &&
+				(pp->mpp->san_path_err_recovery_time >0))) {
+		return 0;
+	}
+
+	if (pp->disable_reinstate) {
+		/* If we don't know how much time has passed, automatically
+		 * reinstate the path, just to be safe. Also, if there are
+		 * no other usable paths, reinstate the path
+		 */
+		if (clock_gettime(CLOCK_MONOTONIC, &curr_time) != 0 ||
+				pp->mpp->nr_active == 0) {
+			condlog(2, "%s : reinstating path early", pp->dev);
+			goto reinstate_path;
+		}
+		if ((curr_time.tv_sec - pp->dis_reinstate_time ) > pp->mpp->san_path_err_recovery_time) {
+			condlog(2,"%s : reinstate the path after err recovery time", pp->dev);
+			goto reinstate_path;
+		}
+		return 1;
+	}
+	/* forget errors on a working path */
+	if ((pp->state == PATH_UP || pp->state == PATH_GHOST) &&
+			pp->path_failures > 0) {
+		if (pp->san_path_err_forget_rate > 0){
+			pp->san_path_err_forget_rate--;
+		} else {
+			/* for every san_path_err_forget_rate number of
+			 * successful path checks decrement path_failures by 1
+			 */
+			pp->path_failures--;
+			pp->san_path_err_forget_rate = pp->mpp->san_path_err_forget_rate;
+		}
+		return 0;
+	}
+
+	/* If the path isn't recovering from a failed state, do nothing */
+	if (pp->state != PATH_DOWN && pp->state != PATH_SHAKY &&
+			pp->state != PATH_TIMEOUT)
+		return 0;
+
+	if (pp->path_failures == 0)
+		pp->san_path_err_forget_rate = pp->mpp->san_path_err_forget_rate;
+
+	pp->path_failures++;
+
+	/* if we don't know the currently time, we don't know how long to
+	 * delay the path, so there's no point in checking if we should
+	 */
+
+	if (clock_gettime(CLOCK_MONOTONIC, &curr_time) != 0)
+		return 0;
+	/* when path failures has exceeded the san_path_err_threshold
+	 * place the path in delayed state till san_path_err_recovery_time
+	 * so that the cutomer can rectify the issue within this time. After
+	 * the completion of san_path_err_recovery_time it should
+	 * automatically reinstate the path
+	 */
+	if (pp->path_failures > pp->mpp->san_path_err_threshold) {
+		condlog(2, "%s : hit error threshold. Delaying path reinstatement", pp->dev);
+		pp->dis_reinstate_time = curr_time.tv_sec;
+		pp->disable_reinstate = 1;
+
+		return 1;
+	} else {
+		return 0;
+	}
+
+reinstate_path:
+	pp->path_failures = 0;
+	pp->disable_reinstate = 0;
+	pp->san_path_err_forget_rate = 0;
+	return 0;
+}
+
 /*
  * Returns '1' if the path has been checked, '-1' if it was blacklisted
  * and '0' otherwise
@@ -1980,6 +2058,12 @@ check_path (struct vectors * vecs, struct path * pp, int ticks)
 	if (!pp->mpp)
 		return 0;
 
+	if ((newstate == PATH_UP || newstate == PATH_GHOST) &&
+			check_path_reinstate_state(pp)) {
+		pp->state = PATH_DELAYED;
+		return 1;
+	}
+
 	if (pp->io_err_disable_reinstate && hit_io_err_recheck_time(pp)) {
 		pp->state = PATH_SHAKY;
 		/*
-- 
2.19.2




More information about the dm-devel mailing list