From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Wilck Subject: [PATCH v5 15/22] libmultipath: implement find_multipaths_timeout Date: Sat, 14 Apr 2018 00:00:08 +0200 Message-ID: <20180413220015.7032-16-mwilck@suse.com> References: <20180413220015.7032-1-mwilck@suse.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180413220015.7032-1-mwilck@suse.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Christophe Varoqui , Benjamin Marzinski Cc: dm-devel@redhat.com, Martin Wilck List-Id: dm-devel.ids 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 Reviewed-by: Benjamin Marzinski --- libmultipath/config.h | 1 + libmultipath/defaults.h | 2 ++ libmultipath/dict.c | 7 +++++++ libmultipath/propsel.c | 25 +++++++++++++++++++++++++ libmultipath/propsel.h | 1 + libmultipath/structs.h | 1 + multipath/multipath.conf.5 | 18 ++++++++++++++++++ 7 files changed, 55 insertions(+) diff --git a/libmultipath/config.h b/libmultipath/config.h index c71d972b..6e69a37e 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 19ad2bfc..d7b87b44 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 b03197b6..eda3f1f0 100644 --- a/libmultipath/dict.c +++ b/libmultipath/dict.c @@ -491,6 +491,10 @@ 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) { @@ -1527,6 +1531,9 @@ 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 2d3b7adf..627d3665 100644 --- a/libmultipath/propsel.c +++ b/libmultipath/propsel.c @@ -953,3 +953,28 @@ 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) +{ + const 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 "unknown" 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 unknown 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 136f9060..a022beef 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 1d3a34f6..eb6a1788 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 6965dacb..3a34aef3 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 +unknown, 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