[dm-devel] [PATCH 6/6] multipath: add "ghost_delay" parameter
Christophe Varoqui
christophe.varoqui at opensvc.com
Wed Nov 15 22:41:48 UTC 2017
Hi Ben,
the patchset is merged until this patch.
Can you consider rebasing it ?
Thanks,
Christophe.
On Wed, Nov 8, 2017 at 1:15 AM, Benjamin Marzinski <bmarzins at redhat.com>
wrote:
> If the lower-priority passive paths for a multipath device appear first,
> IO can go to them and cause the hardware handler to activate them,
> before the higher priority paths appear, causing the devices to
> failback. Setting the "ghost_delay" parameter to a value greater than
> 0 can avoid this ping-ponging by causing udev to not mark the device as
> Ready after its initial creation until either an active path appears,
> or ghost_delay seconds have passed. Multipathd does this by setting
> the MPATH_UDEV_NO_PATHS_FLAG.
>
> Signed-off-by: Benjamin Marzinski <bmarzins at redhat.com>
> ---
> libmultipath/config.c | 3 +++
> libmultipath/config.h | 3 +++
> libmultipath/configure.c | 11 +++++++++++
> libmultipath/defaults.h | 1 +
> libmultipath/devmapper.c | 2 +-
> libmultipath/dict.c | 14 ++++++++++++++
> libmultipath/hwtable.c | 1 +
> libmultipath/propsel.c | 15 +++++++++++++++
> libmultipath/propsel.h | 1 +
> libmultipath/structs.h | 7 +++++++
> multipath/multipath.conf.5 | 19 +++++++++++++++++++
> multipathd/main.c | 28 +++++++++++++++++++++++++++-
> 12 files changed, 103 insertions(+), 2 deletions(-)
>
> diff --git a/libmultipath/config.c b/libmultipath/config.c
> index ea2359a..9486116 100644
> --- a/libmultipath/config.c
> +++ b/libmultipath/config.c
> @@ -351,6 +351,7 @@ merge_hwe (struct hwentry * dst, struct hwentry * src)
> merge_num(delay_wait_checks);
> merge_num(skip_kpartx);
> merge_num(max_sectors_kb);
> + merge_num(ghost_delay);
> merge_num(san_path_err_threshold);
> merge_num(san_path_err_forget_rate);
> merge_num(san_path_err_recovery_time);
> @@ -422,6 +423,7 @@ store_hwe (vector hwtable, struct hwentry * dhwe)
> hwe->retain_hwhandler = dhwe->retain_hwhandler;
> hwe->detect_prio = dhwe->detect_prio;
> hwe->detect_checker = dhwe->detect_checker;
> + hwe->ghost_delay = dhwe->ghost_delay;
>
> if (dhwe->bl_product && !(hwe->bl_product = set_param_str(dhwe->bl_
> product)))
> goto out;
> @@ -622,6 +624,7 @@ load_config (char * file)
> conf->uev_wait_timeout = DEFAULT_UEV_WAIT_TIMEOUT;
> conf->disable_changed_wwids = DEFAULT_DISABLE_CHANGED_WWIDS;
> conf->remove_retries = 0;
> + conf->ghost_delay = DEFAULT_GHOST_DELAY;
>
> /*
> * preload default hwtable
> diff --git a/libmultipath/config.h b/libmultipath/config.h
> index 240730b..67ff983 100644
> --- a/libmultipath/config.h
> +++ b/libmultipath/config.h
> @@ -80,6 +80,7 @@ struct hwentry {
> int san_path_err_recovery_time;
> int skip_kpartx;
> int max_sectors_kb;
> + int ghost_delay;
> char * bl_product;
> };
>
> @@ -112,6 +113,7 @@ struct mpentry {
> int san_path_err_recovery_time;
> int skip_kpartx;
> int max_sectors_kb;
> + int ghost_delay;
> uid_t uid;
> gid_t gid;
> mode_t mode;
> @@ -170,6 +172,7 @@ struct config {
> int disable_changed_wwids;
> int remove_retries;
> int max_sectors_kb;
> + int ghost_delay;
> unsigned int version[3];
>
> char * multipath_dir;
> diff --git a/libmultipath/configure.c b/libmultipath/configure.c
> index 7a3db31..e2f393f 100644
> --- a/libmultipath/configure.c
> +++ b/libmultipath/configure.c
> @@ -300,6 +300,7 @@ int setup_map(struct multipath *mpp, char *params, int
> params_size)
> select_san_path_err_recovery_time(conf, mpp);
> select_skip_kpartx(conf, mpp);
> select_max_sectors_kb(conf, mpp);
> + select_ghost_delay(conf, mpp);
>
> sysfs_set_scsi_tmo(mpp, conf->checkint);
> put_multipath_config(conf);
> @@ -760,6 +761,9 @@ int domap(struct multipath *mpp, char *params, int
> is_daemon)
> }
>
> sysfs_set_max_sectors_kb(mpp, 0);
> + if (is_daemon && mpp->ghost_delay > 0 && mpp->nr_active &&
> + pathcount(mpp, PATH_GHOST) == mpp->nr_active)
> + mpp->ghost_delay_tick = mpp->ghost_delay;
> r = dm_addmap_create(mpp, params);
>
> lock_multipath(mpp, 0);
> @@ -767,11 +771,15 @@ int domap(struct multipath *mpp, char *params, int
> is_daemon)
>
> case ACT_RELOAD:
> sysfs_set_max_sectors_kb(mpp, 1);
> + if (mpp->ghost_delay_tick > 0 && pathcount(mpp, PATH_UP))
> + mpp->ghost_delay_tick = 0;
> r = dm_addmap_reload(mpp, params, 0);
> break;
>
> case ACT_RESIZE:
> sysfs_set_max_sectors_kb(mpp, 1);
> + if (mpp->ghost_delay_tick > 0 && pathcount(mpp, PATH_UP))
> + mpp->ghost_delay_tick = 0;
> r = dm_addmap_reload(mpp, params, 1);
> break;
>
> @@ -789,6 +797,9 @@ int domap(struct multipath *mpp, char *params, int
> is_daemon)
> put_multipath_config(conf);
> if (r) {
> sysfs_set_max_sectors_kb(mpp, 1);
> + if (mpp->ghost_delay_tick > 0 &&
> + pathcount(mpp, PATH_UP))
> + mpp->ghost_delay_tick = 0;
> r = dm_addmap_reload(mpp, params, 0);
> }
> break;
> diff --git a/libmultipath/defaults.h b/libmultipath/defaults.h
> index 740ccf4..c9e3411 100644
> --- a/libmultipath/defaults.h
> +++ b/libmultipath/defaults.h
> @@ -40,6 +40,7 @@
> #define DEFAULT_SKIP_KPARTX SKIP_KPARTX_OFF
> #define DEFAULT_DISABLE_CHANGED_WWIDS 0
> #define DEFAULT_MAX_SECTORS_KB MAX_SECTORS_KB_UNDEF
> +#define DEFAULT_GHOST_DELAY GHOST_DELAY_OFF
>
> #define DEFAULT_CHECKINT 5
> #define MAX_CHECKINT(a) (a << 2)
> diff --git a/libmultipath/devmapper.c b/libmultipath/devmapper.c
> index fcac6bc..573fc75 100644
> --- a/libmultipath/devmapper.c
> +++ b/libmultipath/devmapper.c
> @@ -378,7 +378,7 @@ static uint16_t build_udev_flags(const struct
> multipath *mpp, int reload)
> /* DM_UDEV_DISABLE_LIBRARY_FALLBACK is added in dm_addmap */
> return (mpp->skip_kpartx == SKIP_KPARTX_ON ?
> MPATH_UDEV_NO_KPARTX_FLAG : 0) |
> - (mpp->nr_active == 0 ?
> + ((mpp->nr_active == 0 || mpp->ghost_delay_tick > 0)?
> MPATH_UDEV_NO_PATHS_FLAG : 0) |
> (reload && !mpp->force_udev_reload ?
> MPATH_UDEV_RELOAD_FLAG : 0);
> diff --git a/libmultipath/dict.c b/libmultipath/dict.c
> index 36cccc9..54652d4 100644
> --- a/libmultipath/dict.c
> +++ b/libmultipath/dict.c
> @@ -1110,6 +1110,16 @@ 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(ghost_delay, set_off_int_undef)
> +declare_def_snprint(ghost_delay, print_off_int_undef)
> +declare_ovr_handler(ghost_delay, set_off_int_undef)
> +declare_ovr_snprint(ghost_delay, print_off_int_undef)
> +declare_hw_handler(ghost_delay, set_off_int_undef)
> +declare_hw_snprint(ghost_delay, print_off_int_undef)
> +declare_mp_handler(ghost_delay, set_off_int_undef)
> +declare_mp_snprint(ghost_delay, print_off_int_undef)
> +
> static int
> def_uxsock_timeout_handler(struct config *conf, vector strvec)
> {
> @@ -1456,6 +1466,7 @@ init_keywords(vector keywords)
> install_keyword("disable_changed_wwids",
> &def_disable_changed_wwids_handler, &snprint_def_disable_changed_wwids);
> 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);
> __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);
> @@ -1535,6 +1546,7 @@ init_keywords(vector keywords)
> install_keyword("san_path_err_recovery_time",
> &hw_san_path_err_recovery_time_handler, &snprint_hw_san_path_err_
> recovery_time);
> install_keyword("skip_kpartx", &hw_skip_kpartx_handler,
> &snprint_hw_skip_kpartx);
> install_keyword("max_sectors_kb", &hw_max_sectors_kb_handler,
> &snprint_hw_max_sectors_kb);
> + install_keyword("ghost_delay", &hw_ghost_delay_handler,
> &snprint_hw_ghost_delay);
> install_sublevel_end();
>
> install_keyword_root("overrides", &overrides_handler);
> @@ -1569,6 +1581,7 @@ init_keywords(vector keywords)
>
> install_keyword("skip_kpartx", &ovr_skip_kpartx_handler,
> &snprint_ovr_skip_kpartx);
> install_keyword("max_sectors_kb", &ovr_max_sectors_kb_handler,
> &snprint_ovr_max_sectors_kb);
> + install_keyword("ghost_delay", &ovr_ghost_delay_handler,
> &snprint_ovr_ghost_delay);
>
> install_keyword_root("multipaths", &multipaths_handler);
> install_keyword_multi("multipath", &multipath_handler, NULL);
> @@ -1600,5 +1613,6 @@ init_keywords(vector keywords)
> install_keyword("san_path_err_recovery_time",
> &mp_san_path_err_recovery_time_handler, &snprint_mp_san_path_err_
> recovery_time);
> install_keyword("skip_kpartx", &mp_skip_kpartx_handler,
> &snprint_mp_skip_kpartx);
> install_keyword("max_sectors_kb", &mp_max_sectors_kb_handler,
> &snprint_mp_max_sectors_kb);
> + install_keyword("ghost_delay", &mp_ghost_delay_handler,
> &snprint_mp_ghost_delay);
> install_sublevel_end();
> }
> diff --git a/libmultipath/hwtable.c b/libmultipath/hwtable.c
> index 78de1fa..7226fb1 100644
> --- a/libmultipath/hwtable.c
> +++ b/libmultipath/hwtable.c
> @@ -72,6 +72,7 @@
> .delay_wait_checks = DELAY_CHECKS_OFF,
> .skip_kpartx = SKIP_KPARTX_OFF,
> .max_sectors_kb = MAX_SECTORS_KB_UNDEF,
> + .ghost_delay = GHOST_DELAY_OFF
> },
> #endif
>
> diff --git a/libmultipath/propsel.c b/libmultipath/propsel.c
> index 00adc0d..6721cc6 100644
> --- a/libmultipath/propsel.c
> +++ b/libmultipath/propsel.c
> @@ -835,3 +835,18 @@ out:
> origin);
> return 0;
> }
> +
> +int select_ghost_delay (struct config *conf, struct multipath * mp)
> +{
> + char *origin, buff[12];
> +
> + mp_set_mpe(ghost_delay);
> + mp_set_ovr(ghost_delay);
> + mp_set_hwe(ghost_delay);
> + mp_set_conf(ghost_delay);
> + mp_set_default(ghost_delay, DEFAULT_GHOST_DELAY);
> +out:
> + print_off_int_undef(buff, 12, &mp->ghost_delay);
> + condlog(3, "%s: ghost_delay = %s %s", mp->alias, buff, origin);
> + return 0;
> +}
> diff --git a/libmultipath/propsel.h b/libmultipath/propsel.h
> index f8e96d8..494fb10 100644
> --- a/libmultipath/propsel.h
> +++ b/libmultipath/propsel.h
> @@ -25,6 +25,7 @@ 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_ghost_delay(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);
> diff --git a/libmultipath/structs.h b/libmultipath/structs.h
> index f06824a..d2d7701 100644
> --- a/libmultipath/structs.h
> +++ b/libmultipath/structs.h
> @@ -167,6 +167,11 @@ enum no_undef_states {
> NU_UNDEF = 0,
> };
>
> +enum ghost_delay_states {
> + GHOST_DELAY_OFF = NU_NO,
> + GHOST_DELAY_UNDEF = NU_UNDEF,
> +};
> +
> enum initialized_states {
> INIT_FAILED,
> INIT_MISSING_UDEV,
> @@ -282,6 +287,8 @@ struct multipath {
> int max_sectors_kb;
> int force_readonly;
> int force_udev_reload;
> + int ghost_delay;
> + int ghost_delay_tick;
> unsigned int dev_loss;
> uid_t uid;
> gid_t gid;
> diff --git a/multipath/multipath.conf.5 b/multipath/multipath.conf.5
> index 4bd1a8d..8783124 100644
> --- a/multipath/multipath.conf.5
> +++ b/multipath/multipath.conf.5
> @@ -1017,6 +1017,19 @@ The default is: \fB<device dependent>\fR
> .RE
> .
> .
> +.TP
> +.B ghost_delay
> +Sets the number of seconds that multipath will wait after creating a
> device
> +with only ghost paths before marking it ready for use in systemd. This
> gives
> +the active paths time to appear before the multipath runs the hardware
> handler
> +to switch the ghost paths to active ones. Setting this to \fI0\fR or
> \fIon\fR
> +makes multipath immediately mark a device with only ghost paths as ready.
> +.RS
> +.TP
> +The default is \fBno\fR
> +.RE
> +.
> +.
> .\" ------------------------------------------------------------
> ----------------
> .SH "blacklist section"
> .\" ------------------------------------------------------------
> ----------------
> @@ -1157,6 +1170,8 @@ are taken from the \fIdefaults\fR or \fIdevices\fR
> section:
> .B skip_kpartx
> .TP
> .B max_sectors_kb
> +.TP
> +.B ghost_delay
> .RE
> .PD
> .LP
> @@ -1284,6 +1299,8 @@ section:
> .B skip_kpartx
> .TP
> .B max_sectors_kb
> +.TP
> +.B ghost_delay
> .RE
> .PD
> .LP
> @@ -1354,6 +1371,8 @@ the values are taken from the \fIdevices\fR or
> \fIdefaults\fR sections:
> .B delay_wait_checks
> .TP
> .B skip_kpartx
> +.TP
> +.B ghost_delay
> .RE
> .PD
> .LP
> diff --git a/multipathd/main.c b/multipathd/main.c
> index 8049da2..c475fcd 100644
> --- a/multipathd/main.c
> +++ b/multipathd/main.c
> @@ -351,6 +351,8 @@ sync_map_state(struct multipath *mpp)
> pp->state == PATH_WILD ||
> pp->state == PATH_DELAYED)
> continue;
> + if (mpp->ghost_delay_tick > 0)
> + continue;
> if ((pp->dmstate == PSTATE_FAILED ||
> pp->dmstate == PSTATE_UNDEF) &&
> (pp->state == PATH_UP || pp->state ==
> PATH_GHOST))
> @@ -735,7 +737,8 @@ ev_add_path (struct path * pp, struct vectors * vecs,
> int need_do_map)
> mpp = find_mp_by_wwid(vecs->mpvec, pp->wwid);
> if (mpp && mpp->wait_for_udev &&
> (pathcount(mpp, PATH_UP) > 0 ||
> - (pathcount(mpp, PATH_GHOST) > 0 && pp->tpgs !=
> TPGS_IMPLICIT))) {
> + (pathcount(mpp, PATH_GHOST) > 0 && pp->tpgs != TPGS_IMPLICIT
> &&
> + mpp->ghost_delay_tick <= 0))) {
> /* if wait_for_udev is set and valid paths exist */
> condlog(2, "%s: delaying path addition until %s is fully
> initialized", pp->dev, mpp->alias);
> mpp->wait_for_udev = 2;
> @@ -1416,6 +1419,28 @@ missing_uev_wait_tick(struct vectors *vecs)
> }
>
> static void
> +ghost_delay_tick(struct vectors *vecs)
> +{
> + struct multipath * mpp;
> + unsigned int i;
> +
> + vector_foreach_slot (vecs->mpvec, mpp, i) {
> + if (mpp->ghost_delay_tick <= 0)
> + continue;
> + if (--mpp->ghost_delay_tick <= 0) {
> + condlog(0, "%s: timed out waiting for active path",
> + mpp->alias);
> + mpp->force_udev_reload = 1;
> + if (update_map(mpp, vecs) != 0) {
> + /* update_map removed map */
> + i--;
> + continue;
> + }
> + }
> + }
> +}
> +
> +static void
> defered_failback_tick (vector mpvec)
> {
> struct multipath * mpp;
> @@ -1961,6 +1986,7 @@ checkerloop (void *ap)
> defered_failback_tick(vecs->mpvec);
> retry_count_tick(vecs->mpvec);
> missing_uev_wait_tick(vecs);
> + ghost_delay_tick(vecs);
> lock_cleanup_pop(vecs->lock);
>
> if (count)
> --
> 2.7.4
>
>
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