[PATCH v2 3/4] libmultipath: deprecate rr_min_io

Since the kernel now requires paths to have a minio of 1, rr_min_io is
currently useless. However, bio-based multipath performs significantly
worse than request-based multipath. Part of that is because bio-based
multipath will call the path selector to pick a new path for every bio,
making it very unlikely that adjacent bios will be merged. So this patch
leaves the bio-based minio code around, since we may revisit this in the
future. It does disable setting the value in multipath.conf, and changes
the default to 1. Also, it fixes select_minio() to actually check if the
multipath device is bio-based or request-based, and it takes out the
code for modifying the minio based on the status of the "least-pending"
path selector, because that no longer exists.

Signed-off-by: Benjamin Marzinski <[email protected]>
---
 libmultipath/defaults.h |  2 +-
 libmultipath/dict.c     | 18 +++++-------------
 libmultipath/dmparser.c | 12 +-----------
 libmultipath/hwtable.c  |  1 -
 libmultipath/propsel.c  |  8 +++-----
 tests/test-lib.c        |  2 --
 6 files changed, 10 insertions(+), 33 deletions(-)

diff --git a/libmultipath/defaults.h b/libmultipath/defaults.h
index a6e808db..ea1fce0e 100644
--- a/libmultipath/defaults.h
+++ b/libmultipath/defaults.h
@@ -16,7 +16,7 @@
 #define DEFAULT_ALIAS_PREFIX	"mpath"
 #define DEFAULT_FEATURES	"0"
 #define DEFAULT_HWHANDLER	"0"
-#define DEFAULT_MINIO		1000
+#define DEFAULT_MINIO		1
 #define DEFAULT_MINIO_RQ	1
 #define DEFAULT_PGPOLICY	FAILOVER
 #define DEFAULT_FAILBACK	-FAILBACK_MANUAL
diff --git a/libmultipath/dict.c b/libmultipath/dict.c
index 3b6584ec..0e947b1d 100644
--- a/libmultipath/dict.c
+++ b/libmultipath/dict.c
@@ -746,15 +746,6 @@ declare_ovr_snprint(checker_name, print_str)
 declare_hw_handler(checker_name, set_str)
 declare_hw_snprint(checker_name, print_str)
 
-declare_def_range_handler(minio, 0, INT_MAX)
-declare_def_snprint_defint(minio, print_int, DEFAULT_MINIO)
-declare_ovr_range_handler(minio, 0, INT_MAX)
-declare_ovr_snprint(minio, print_nonzero)
-declare_hw_range_handler(minio, 0, INT_MAX)
-declare_hw_snprint(minio, print_nonzero)
-declare_mp_range_handler(minio, 0, INT_MAX)
-declare_mp_snprint(minio, print_nonzero)
-
 declare_def_handler(queue_without_daemon, set_yes_no)
 static int
 snprint_def_queue_without_daemon(struct config *conf, struct strbuf *buff,
@@ -2108,6 +2099,7 @@ declare_deprecated_handler(pg_timeout, "(not set)")
 declare_deprecated_handler(bindings_file, DEFAULT_BINDINGS_FILE)
 declare_deprecated_handler(wwids_file, DEFAULT_WWIDS_FILE)
 declare_deprecated_handler(prkeys_file, DEFAULT_PRKEYS_FILE)
+declare_deprecated_handler(minio, "1")
 declare_deprecated_handler(minio_rq, "1")
 declare_deprecated_handler(rr_weight, "uniform")
 
@@ -2135,7 +2127,7 @@ init_keywords(vector keywords)
 	install_keyword("checker", &def_checker_name_handler, NULL);
 	install_keyword("alias_prefix", &def_alias_prefix_handler, &snprint_def_alias_prefix);
 	install_keyword("failback", &def_pgfailback_handler, &snprint_def_pgfailback);
-	install_keyword("rr_min_io", &def_minio_handler, &snprint_def_minio);
+	install_keyword("rr_min_io", &deprecated_minio_handler, &snprint_deprecated);
 	install_keyword("rr_min_io_rq", &deprecated_minio_rq_handler, &snprint_deprecated);
 	install_keyword("max_fds", &max_fds_handler, &snprint_max_fds);
 	install_keyword("rr_weight", &deprecated_rr_weight_handler, &snprint_deprecated);
@@ -2245,7 +2237,7 @@ init_keywords(vector keywords)
 	install_keyword("failback", &hw_pgfailback_handler, &snprint_hw_pgfailback);
 	install_keyword("rr_weight", &deprecated_rr_weight_handler, &snprint_deprecated);
 	install_keyword("no_path_retry", &hw_no_path_retry_handler, &snprint_hw_no_path_retry);
-	install_keyword("rr_min_io", &hw_minio_handler, &snprint_hw_minio);
+	install_keyword("rr_min_io", &deprecated_minio_handler, &snprint_deprecated);
 	install_keyword("rr_min_io_rq", &deprecated_minio_rq_handler, &snprint_deprecated);
 	install_keyword("pg_timeout", &deprecated_pg_timeout_handler, &snprint_deprecated);
 	install_keyword("flush_on_last_del", &hw_flush_on_last_del_handler, &snprint_hw_flush_on_last_del);
@@ -2291,7 +2283,7 @@ init_keywords(vector keywords)
 	install_keyword("failback", &ovr_pgfailback_handler, &snprint_ovr_pgfailback);
 	install_keyword("rr_weight", &deprecated_rr_weight_handler, &snprint_deprecated);
 	install_keyword("no_path_retry", &ovr_no_path_retry_handler, &snprint_ovr_no_path_retry);
-	install_keyword("rr_min_io", &ovr_minio_handler, &snprint_ovr_minio);
+	install_keyword("rr_min_io", &deprecated_minio_handler, &snprint_deprecated);
 	install_keyword("rr_min_io_rq", &deprecated_minio_rq_handler, &snprint_deprecated);
 	install_keyword("flush_on_last_del", &ovr_flush_on_last_del_handler, &snprint_ovr_flush_on_last_del);
 	install_keyword("fast_io_fail_tmo", &ovr_fast_io_fail_handler, &snprint_ovr_fast_io_fail);
@@ -2340,7 +2332,7 @@ init_keywords(vector keywords)
 	install_keyword("failback", &mp_pgfailback_handler, &snprint_mp_pgfailback);
 	install_keyword("rr_weight", &deprecated_rr_weight_handler, &snprint_deprecated);
 	install_keyword("no_path_retry", &mp_no_path_retry_handler, &snprint_mp_no_path_retry);
-	install_keyword("rr_min_io", &mp_minio_handler, &snprint_mp_minio);
+	install_keyword("rr_min_io", &deprecated_minio_handler, &snprint_deprecated);
 	install_keyword("rr_min_io_rq", &deprecated_minio_rq_handler, &snprint_deprecated);
 	install_keyword("pg_timeout", &deprecated_pg_timeout_handler, &snprint_deprecated);
 	install_keyword("flush_on_last_del", &mp_flush_on_last_del_handler, &snprint_mp_flush_on_last_del);
diff --git a/libmultipath/dmparser.c b/libmultipath/dmparser.c
index 97300668..83760e30 100644
--- a/libmultipath/dmparser.c
+++ b/libmultipath/dmparser.c
@@ -337,7 +337,6 @@ int disassemble_status(const char *params, struct multipath *mpp)
 	int num_pg;
 	int num_pg_args;
 	int num_paths;
-	int def_minio = 0;
 	struct path * pp;
 	struct pathgroup * pgp;
 
@@ -507,16 +506,7 @@ int disassemble_status(const char *params, struct multipath *mpp)
 			 * selector args
 			 */
 			for (k = 0; k < num_pg_args; k++) {
-				if (!strncmp(mpp->selector,
-					     "least-pending", 13)) {
-					p += get_word(p, &word);
-					if (sscanf(word,"%d:*d",
-						   &def_minio) == 1 &&
-					    def_minio != mpp->minio)
-							mpp->minio = def_minio;
-					free(word);
-				} else
-					p += get_word(p, NULL);
+				p += get_word(p, NULL);
 			}
 		}
 	}
diff --git a/libmultipath/hwtable.c b/libmultipath/hwtable.c
index 36646540..a8fbfa70 100644
--- a/libmultipath/hwtable.c
+++ b/libmultipath/hwtable.c
@@ -57,7 +57,6 @@
 		.prio_args     = "",
 		.pgfailback    = -FAILBACK_MANUAL,
 		.no_path_retry = NO_PATH_RETRY_UNDEF,
-		.minio         = 1000,
 		.flush_on_last_del = FLUSH_UNUSED,
 		.user_friendly_names = USER_FRIENDLY_NAMES_OFF,
 		.fast_io_fail  = 5,
diff --git a/libmultipath/propsel.c b/libmultipath/propsel.c
index 7f0b66ec..277214f6 100644
--- a/libmultipath/propsel.c
+++ b/libmultipath/propsel.c
@@ -866,13 +866,11 @@ out:
 int select_minio(struct config *conf, struct multipath *mp)
 {
 	const char *origin;
-	unsigned int minv_dmrq[3] = {1, 1, 0}, version[3];
 
-	if (!libmp_get_version(DM_MPATH_TARGET_VERSION, version)
-	    && VERSION_GE(version, minv_dmrq))
-		mp_set_default(minio, DEFAULT_MINIO_RQ);
-	else
+	if (mp->queue_mode == QUEUE_MODE_BIO)
 		return select_minio_bio(conf, mp);
+
+	mp_set_default(minio, DEFAULT_MINIO_RQ);
 	condlog(3, "%s: minio = %i %s", mp->alias, mp->minio, origin);
 	return 0;
 }
diff --git a/tests/test-lib.c b/tests/test-lib.c
index ea99977f..9a229e47 100644
--- a/tests/test-lib.c
+++ b/tests/test-lib.c
@@ -398,7 +398,6 @@ struct multipath *mock_multipath__(struct vectors *vecs, struct path *pp)
 	struct multipath *mp;
 	struct config *conf;
 	struct mocked_path mop;
-	/* pretend new dm, use minio_rq,  */
 	static const unsigned int fake_dm_tgt_version[3] = { 1, 1, 1 };
 
 	mocked_path_from_path(&mop, pp);
@@ -414,7 +413,6 @@ struct multipath *mock_multipath__(struct vectors *vecs, struct path *pp)
 	select_no_path_retry(conf, mp);
 	will_return(__wrap_libmp_get_version, fake_dm_tgt_version);
 	select_retain_hwhandler(conf, mp);
-	will_return(__wrap_libmp_get_version, fake_dm_tgt_version);
 	select_minio(conf, mp);
 	put_multipath_config(conf);
 
-- 
2.53.0