On Mon, Mar 19, 2018 at 04:01:42PM +0100, Martin Wilck wrote:
> Change the "find_multipaths" option from yes/no to multi-value. This
> option now covers the effects of "find_multipaths" as it used to be,
> plus the -i option to multipath (ignore_wwids) and the -n option to
> multipathd (ignore_new_devs), excluding such combinations of the former
> options that are dangerous or inconsistent.
>
> The possible values for "find_multipaths" are now:
>
> - strict: strictly stick to the WWIDs file; never add new maps automatically
> (new default; upstream behaviour with with find_multipaths "yes" and
> commit 64e27ec "multipathd: imply -n if find_multipaths is set")
> - off|no: multipath like "strict", multipathd like "greedy" (previous
> upstream default)
> - on|yes: set up multipath if >1 paths are seen (current Red Hat/Ubuntu
> behavior with find_multipaths "yes")
> - greedy: set up multipath for all non-blacklisted devices (current SUSE
> default)
> - smart: Like "yes", but try to avoid inconsistencies between udev processing
> and multipathd processing by waiting for path siblings to
> appear (fully implemented in follow-up patches)
>
> The default has been changed to "strict", because "no" may cause inconsistent
> behavior between "multipath -u" and multipathd. This is deliberately a
> conservative choice.
>
> The patch also updates the related man pages.
>
Reviewed-by: Benjamin Marzinski <bmarzins@xxxxxxxxxx>
This patch conflicts with the "multipath: fix rcu thread cancellation
hang" patch I just sent. I will be resending that patch anyways as part
of cleaning up my previous patchsets based on you comments, but we
apparently need to do a better job with managing the rcu read side
critical sections, between get_multipath_config() and
put_multipath_config().
> Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
> ---
> libmultipath/config.h | 2 --
> libmultipath/defaults.h | 2 +-
> libmultipath/dict.c | 47 ++++++++++++++++++++++++++++++++++++++++++++--
> libmultipath/structs.h | 26 +++++++++++++++++++++++++
> libmultipath/wwids.c | 8 ++++----
> multipath/main.c | 6 +++---
> multipath/multipath.8 | 9 ++++++++-
> multipath/multipath.conf.5 | 46 +++++++++++++++++++++++++--------------------
> multipathd/main.c | 6 +-----
> multipathd/multipathd.8 | 8 +++++---
> 10 files changed, 119 insertions(+), 41 deletions(-)
>
> diff --git a/libmultipath/config.h b/libmultipath/config.h
> index a20ac2aac296..21d8e72a2492 100644
> --- a/libmultipath/config.h
> +++ b/libmultipath/config.h
> @@ -139,7 +139,6 @@ struct config {
> int max_fds;
> int force_reload;
> int queue_without_daemon;
> - int ignore_wwids;
> int checker_timeout;
> int flush_on_last_del;
> int attribute_flags;
> @@ -168,7 +167,6 @@ struct config {
> int strict_timing;
> int retrigger_tries;
> int retrigger_delay;
> - int ignore_new_devs;
> int delayed_reconfig;
> int uev_wait_timeout;
> int skip_kpartx;
> diff --git a/libmultipath/defaults.h b/libmultipath/defaults.h
> index 2b270ca46f48..690182c368d9 100644
> --- a/libmultipath/defaults.h
> +++ b/libmultipath/defaults.h
> @@ -17,7 +17,7 @@
> #define DEFAULT_NO_PATH_RETRY NO_PATH_RETRY_UNDEF
> #define DEFAULT_VERBOSITY 2
> #define DEFAULT_REASSIGN_MAPS 0
> -#define DEFAULT_FIND_MULTIPATHS 0
> +#define DEFAULT_FIND_MULTIPATHS FIND_MULTIPATHS_STRICT
> #define DEFAULT_FAST_IO_FAIL 5
> #define DEFAULT_DEV_LOSS_TMO 600
> #define DEFAULT_RETAIN_HWHANDLER RETAIN_HWHANDLER_ON
> diff --git a/libmultipath/dict.c b/libmultipath/dict.c
> index ea273dd91962..a952c60a6f98 100644
> --- a/libmultipath/dict.c
> +++ b/libmultipath/dict.c
> @@ -233,8 +233,51 @@ declare_def_snprint(multipath_dir, print_str)
> declare_def_handler(partition_delim, set_str)
> declare_def_snprint(partition_delim, print_str)
>
> -declare_def_handler(find_multipaths, set_yes_no)
> -declare_def_snprint(find_multipaths, print_yes_no)
> +static const char *find_multipaths_optvals[] = {
> + [FIND_MULTIPATHS_OFF] = "off",
> + [FIND_MULTIPATHS_ON] = "on",
> + [FIND_MULTIPATHS_STRICT] = "strict",
> + [FIND_MULTIPATHS_GREEDY] = "greedy",
> +};
> +
> +static int
> +def_find_multipaths_handler(struct config *conf, vector strvec)
> +{
> + char *buff;
> + int i;
> +
> + if (set_yes_no_undef(strvec, &conf->find_multipaths) == 0 &&
> + conf->find_multipaths != YNU_UNDEF)
> + return 0;
> +
> + buff = set_value(strvec);
> + if (!buff)
> + return 1;
> +
> + for (i = FIND_MULTIPATHS_OFF; i < __FIND_MULTIPATHS_LAST; i++) {
> + if (find_multipaths_optvals[i] != NULL &&
> + !strcmp(buff, find_multipaths_optvals[i])) {
> + conf->find_multipaths = i;
> + break;
> + }
> + }
> +
> + if (conf->find_multipaths == YNU_UNDEF) {
> + condlog(0, "illegal value for find_multipaths: %s", buff);
> + conf->find_multipaths = DEFAULT_FIND_MULTIPATHS;
> + }
> +
> + FREE(buff);
> + return 0;
> +}
> +
> +static int
> +snprint_def_find_multipaths(struct config *conf, char *buff, int len,
> + const void *data)
> +{
> + return print_str(buff, len,
> + find_multipaths_optvals[conf->find_multipaths]);
> +}
>
> declare_def_handler(selector, set_str)
> declare_def_snprint_defstr(selector, print_str, DEFAULT_SELECTOR)
> diff --git a/libmultipath/structs.h b/libmultipath/structs.h
> index 88a4b7862393..d6482f84f0e6 100644
> --- a/libmultipath/structs.h
> +++ b/libmultipath/structs.h
> @@ -102,6 +102,32 @@ enum yes_no_undef_states {
> YNU_YES,
> };
>
> +#define _FIND_MULTIPATHS_F (1 << 1)
> +#define _FIND_MULTIPATHS_I (1 << 2)
> +#define _FIND_MULTIPATHS_N (1 << 3)
> +/*
> + * _FIND_MULTIPATHS_F must have the same value as YNU_YES.
> + * Generate a compile time error if that isn't the case.
> + */
> +char ___error1___[-(_FIND_MULTIPATHS_F != YNU_YES)];
> +
> +#define find_multipaths_on(conf) \
> + (!!((conf)->find_multipaths & _FIND_MULTIPATHS_F))
> +#define ignore_wwids(conf) \
> + (!!((conf)->find_multipaths & _FIND_MULTIPATHS_I))
> +#define ignore_new_devs(conf) \
> + (!!((conf)->find_multipaths & _FIND_MULTIPATHS_N))
> +
> +enum find_multipaths_states {
> + FIND_MULTIPATHS_UNDEF = YNU_UNDEF,
> + FIND_MULTIPATHS_OFF = YNU_NO,
> + FIND_MULTIPATHS_ON = _FIND_MULTIPATHS_F,
> + FIND_MULTIPATHS_STRICT = _FIND_MULTIPATHS_F|_FIND_MULTIPATHS_N,
> + FIND_MULTIPATHS_GREEDY = _FIND_MULTIPATHS_I,
> + FIND_MULTIPATHS_SMART = _FIND_MULTIPATHS_F|_FIND_MULTIPATHS_I,
> + __FIND_MULTIPATHS_LAST,
> +};
> +
> enum flush_states {
> FLUSH_UNDEF = YNU_UNDEF,
> FLUSH_DISABLED = YNU_NO,
> diff --git a/libmultipath/wwids.c b/libmultipath/wwids.c
> index ea56911b4607..5a2e86dcd7e2 100644
> --- a/libmultipath/wwids.c
> +++ b/libmultipath/wwids.c
> @@ -274,20 +274,20 @@ out:
> int
> should_multipath(struct path *pp1, vector pathvec, vector mpvec)
> {
> - int i, ignore_new_devs;
> + int i, ignore_new;
> struct path *pp2;
> struct config *conf;
>
> conf = get_multipath_config();
> - ignore_new_devs = conf->ignore_new_devs;
> - if (!conf->find_multipaths && !ignore_new_devs) {
> + ignore_new = ignore_new_devs(conf);
> + if (!find_multipaths_on(conf) && !ignore_new) {
> put_multipath_config(conf);
> return 1;
> }
> put_multipath_config(conf);
>
> condlog(4, "checking if %s should be multipathed", pp1->dev);
> - if (!ignore_new_devs) {
> + if (!ignore_new) {
> char tmp_wwid[WWID_SIZE];
> struct multipath *mp = find_mp_by_wwid(mpvec, pp1->wwid);
>
> diff --git a/multipath/main.c b/multipath/main.c
> index 19c729d8e058..3944fd504de2 100644
> --- a/multipath/main.c
> +++ b/multipath/main.c
> @@ -441,11 +441,11 @@ configure (struct config *conf, enum mpath_cmds cmd,
> * Paths listed in the wwids file are always considered valid.
> */
> if (cmd == CMD_VALID_PATH) {
> - if ((!conf->find_multipaths && conf->ignore_wwids) ||
> + if ((!find_multipaths_on(conf) && ignore_wwids(conf)) ||
> check_wwids_file(refwwid, 0) == 0)
> r = 0;
> if (r == 0 ||
> - !conf->find_multipaths || !conf->ignore_wwids) {
> + !find_multipaths_on(conf) || !ignore_wwids(conf)) {
> printf("%s %s a valid multipath device path\n",
> devpath, r == 0 ? "is" : "is not");
> goto out;
> @@ -737,7 +737,7 @@ main (int argc, char *argv[])
> conf->force_reload = FORCE_RELOAD_YES;
> break;
> case 'i':
> - conf->ignore_wwids = 1;
> + conf->find_multipaths |= _FIND_MULTIPATHS_I;
> break;
> case 't':
> r = dump_config(conf);
> diff --git a/multipath/multipath.8 b/multipath/multipath.8
> index 56f870351ee2..329658daeead 100644
> --- a/multipath/multipath.8
> +++ b/multipath/multipath.8
> @@ -94,7 +94,14 @@ Force devmap reload.
> .
> .TP
> .B \-i
> -Ignore WWIDs file when processing devices.
> +Ignore WWIDs file when processing devices. If
> +\fIfind_multipaths strict\fR or \fIfind_multipaths no\fR is set in
> +\fImultipath.conf\fR, multipath only considers devices that are
> +listed in the WWIDs file. This option overrides that behavior. For other values
> +of \fIfind_multipaths\fR, this option has no effect. See the description of
> +\fIfind_multipaths\fR in
> +.BR multipath.conf (5).
> +This option should only be used in rare circumstances.
> .
> .TP
> .B \-B
> diff --git a/multipath/multipath.conf.5 b/multipath/multipath.conf.5
> index c4d0789475a3..6965dacb5c68 100644
> --- a/multipath/multipath.conf.5
> +++ b/multipath/multipath.conf.5
> @@ -951,28 +951,34 @@ The default is: \fBno\fR
> .
> .TP
> .B find_multipaths
> -If set to
> -.I yes
> -, instead of trying to create a multipath device for every non-blacklisted
> -path, multipath will only create a device if one of three condidions are
> -met.
> -.I 1
> -There are at least two non-blacklisted paths with the same WWID,
> -.I 2
> -the user manually forces the creation, by specifying a device with the multipath
> -command, or
> -.I 3
> -a path has the same WWID as a multipath device that was previously created
> -while find_multipaths was set (even if that multipath device doesn't currently
> -exist).
> -Whenever a multipath device is created with find_multipaths set, multipath will
> -remember the WWID of the device, so that it will automatically create the
> -device again, as soon as it sees a path with that WWID. This should allow most
> -users to have multipath automatically choose the correct paths to make into
> -multipath devices, without having to edit the blacklist.
> +This option controls whether multipath and multipathd try to create multipath
> +maps over non-blacklisted devices they encounter. This matters a) when a device is
> +encountered by \fBmultipath -u\fR during udev rule processing (a device is
> +blocked from further processing by higher layers - such as LVM - if and only
> +if it\'s considered a valid multipath device path), and b) when multipathd
> +detects a new device. The following values are possible:
> .RS
> +.TP 10
> +.I strict
> +Both multipath and multipathd treat only such devices as multipath devices
> +which have been part of a multipath map previously, and which are therefore
> +listed in the \fBwwids_file\fR. Users can manually set up multipath maps using the
> +\fBmultipathd add map\fR command. Once set up manually, the map is
> +remembered in the wwids file and will be set up automatically in the future.
> .TP
> -The default is: \fBno\fR
> +.I no
> +Multipath behaves like \fBstrict\fR. Multipathd behaves like \fBgreedy\fR.
> +.TP
> +.I yes
> +Both multipathd and multipath treat a device as multipath device if the
> +conditions for \fBstrict\fR are met, or if at least two non-blacklisted paths
> +with the same WWID have been detected.
> +.TP
> +.I greedy
> +Both multipathd and multipath treat every non-blacklisted device as multipath
> +device path.
> +.TP
> +The default is: \fBstrict\fR
> .RE
> .
> .
> diff --git a/multipathd/main.c b/multipathd/main.c
> index da40595fc7c8..bfbe5f66b324 100644
> --- a/multipathd/main.c
> +++ b/multipathd/main.c
> @@ -2390,8 +2390,6 @@ reconfigure (struct vectors * vecs)
> conf->verbosity = verbosity;
> if (bindings_read_only)
> conf->bindings_read_only = bindings_read_only;
> - if (ignore_new_devs)
> - conf->ignore_new_devs = ignore_new_devs;
> uxsock_timeout = conf->uxsock_timeout;
>
> old = rcu_dereference(multipath_conf);
> @@ -2620,8 +2618,6 @@ child (void * param)
> conf->verbosity = verbosity;
> if (bindings_read_only)
> conf->bindings_read_only = bindings_read_only;
> - if (ignore_new_devs)
> - conf->ignore_new_devs = ignore_new_devs;
> uxsock_timeout = conf->uxsock_timeout;
> rcu_assign_pointer(multipath_conf, conf);
> if (init_checkers(conf->multipath_dir)) {
> @@ -2975,7 +2971,7 @@ main (int argc, char *argv[])
> bindings_read_only = 1;
> break;
> case 'n':
> - ignore_new_devs = 1;
> + condlog(0, "WARNING: ignoring deprecated option -n, use 'ignore_wwids = no' instead");
> break;
> case 'w':
> poll_dmevents = 0;
> diff --git a/multipathd/multipathd.8 b/multipathd/multipathd.8
> index 5c96680c0514..e78ac9ed277f 100644
> --- a/multipathd/multipathd.8
> +++ b/multipathd/multipathd.8
> @@ -25,7 +25,6 @@ multipathd \- Multipath daemon.
> .RB [\| \-v\ \c
> .IR verbosity \|]
> .RB [\| \-B \|]
> -.RB [\| \-n \|]
> .
> .
> .\" ----------------------------------------------------------------------------
> @@ -73,8 +72,11 @@ be viewed by entering '\fIhelp\fR'. When you are finished entering commands, pre
> .
> .TP
> .B \-n
> -Ignore new devices. multipathd will not create a multipath device unless the
> -WWID for the device is already listed in the WWIDs file.
> +\fBIGNORED\fR. Use the option
> +\fIfind_multipaths\fR to control the treatment of newly detected devices by
> +multipathd. See
> +.BR multipath.conf(5).
> +.
> .
> .
> .\" ----------------------------------------------------------------------------
> --
> 2.16.1
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