[dm-devel] [PATCH 09/10] add disable_changed_wwids option
Benjamin Marzinski
bmarzins at redhat.com
Mon Nov 7 14:47:18 UTC 2016
On Sun, Nov 06, 2016 at 01:03:31AM +0100, Xose Vazquez Perez wrote:
> On 10/29/2016 04:55 AM, Benjamin Marzinski wrote:
>
> > If a LUN on a storage device gets remapped while in-use by multipath,
> > it's possible that the multipath device will continue writing to this
> > new LUN, causing corruption. This is not multipath's fault (users
> > should go remapping in-use LUNs), but it's possible for multipath to
> > detect this and disable IO to the device. If disable_changed_wwids
> > is set to "yes", multipathd will detect when a LUN changes wwids when it
> > receives the uevent for this, and will disable access to the device
> > until the LUN is mapped back.
>
> Some info is needed at multipath.conf.5 for this new keyword.
>
Oops! Thanks. I'll send a patch with the manpage info.
-Ben
> > Signed-off-by: Benjamin Marzinski <bmarzins at redhat.com>
> > ---
> > libmultipath/config.c | 1 +
> > libmultipath/config.h | 1 +
> > libmultipath/defaults.h | 1 +
> > libmultipath/dict.c | 4 ++++
> > libmultipath/discovery.c | 15 +++++++--------
> > libmultipath/discovery.h | 1 +
> > libmultipath/structs.h | 1 +
> > multipathd/main.c | 32 ++++++++++++++++++++++++++++++++
> > 8 files changed, 48 insertions(+), 8 deletions(-)
> >
> > diff --git a/libmultipath/config.c b/libmultipath/config.c
> > index bdcad80..a97b318 100644
> > --- a/libmultipath/config.c
> > +++ b/libmultipath/config.c
> > @@ -618,6 +618,7 @@ load_config (char * file)
> > conf->uev_wait_timeout = DEFAULT_UEV_WAIT_TIMEOUT;
> > conf->deferred_remove = DEFAULT_DEFERRED_REMOVE;
> > conf->skip_kpartx = DEFAULT_SKIP_KPARTX;
> > + conf->disable_changed_wwids = DEFAULT_DISABLE_CHANGED_WWIDS;
> >
> > /*
> > * preload default hwtable
> > diff --git a/libmultipath/config.h b/libmultipath/config.h
> > index d59a993..dbdaa44 100644
> > --- a/libmultipath/config.h
> > +++ b/libmultipath/config.h
> > @@ -144,6 +144,7 @@ struct config {
> > int delayed_reconfig;
> > int uev_wait_timeout;
> > int skip_kpartx;
> > + int disable_changed_wwids;
> > unsigned int version[3];
> >
> > char * multipath_dir;
> > diff --git a/libmultipath/defaults.h b/libmultipath/defaults.h
> > index a1fee9b..a72078f 100644
> > --- a/libmultipath/defaults.h
> > +++ b/libmultipath/defaults.h
> > @@ -36,6 +36,7 @@
> > #define DEFAULT_FORCE_SYNC 0
> > #define DEFAULT_PARTITION_DELIM NULL
> > #define DEFAULT_SKIP_KPARTX SKIP_KPARTX_OFF
> > +#define DEFAULT_DISABLE_CHANGED_WWIDS 0
> >
> > #define DEFAULT_CHECKINT 5
> > #define MAX_CHECKINT(a) (a << 2)
> > diff --git a/libmultipath/dict.c b/libmultipath/dict.c
> > index e0a3014..61b6910 100644
> > --- a/libmultipath/dict.c
> > +++ b/libmultipath/dict.c
> > @@ -412,6 +412,9 @@ declare_hw_snprint(skip_kpartx, print_yes_no_undef)
> > declare_mp_handler(skip_kpartx, set_yes_no_undef)
> > declare_mp_snprint(skip_kpartx, print_yes_no_undef)
> >
> > +declare_def_handler(disable_changed_wwids, set_yes_no)
> > +declare_def_snprint(disable_changed_wwids, print_yes_no)
> > +
> > static int
> > def_config_dir_handler(struct config *conf, vector strvec)
> > {
> > @@ -1395,6 +1398,7 @@ init_keywords(vector keywords)
> > install_keyword("retrigger_delay", &def_retrigger_delay_handler, &snprint_def_retrigger_delay);
> > install_keyword("missing_uev_wait_timeout", &def_uev_wait_timeout_handler, &snprint_def_uev_wait_timeout);
> > install_keyword("skip_kpartx", &def_skip_kpartx_handler, &snprint_def_skip_kpartx);
> > + install_keyword("disable_changed_wwids", &def_disable_changed_wwids_handler, &snprint_def_disable_changed_wwids);
> > __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/discovery.c b/libmultipath/discovery.c
> > index bb3116d..756344f 100644
> > --- a/libmultipath/discovery.c
> > +++ b/libmultipath/discovery.c
> > @@ -1538,13 +1538,12 @@ get_prio (struct path * pp)
> > }
> >
> > static int
> > -get_udev_uid(struct path * pp, char *uid_attribute)
> > +get_udev_uid(struct path * pp, char *uid_attribute, struct udev_device *udev)
> > {
> > ssize_t len;
> > const char *value;
> >
> > - value = udev_device_get_property_value(pp->udev,
> > - uid_attribute);
> > + value = udev_device_get_property_value(udev, uid_attribute);
> > if (!value || strlen(value) == 0)
> > value = getenv(uid_attribute);
> > if (value && strlen(value)) {
> > @@ -1625,8 +1624,8 @@ get_vpd_uid(struct path * pp)
> > return get_vpd_sysfs(parent, 0x83, pp->wwid, WWID_SIZE);
> > }
> >
> > -static int
> > -get_uid (struct path * pp, int path_state)
> > +int
> > +get_uid (struct path * pp, int path_state, struct udev_device *udev)
> > {
> > char *c;
> > const char *origin = "unknown";
> > @@ -1639,7 +1638,7 @@ get_uid (struct path * pp, int path_state)
> > put_multipath_config(conf);
> > }
> >
> > - if (!pp->udev) {
> > + if (!udev) {
> > condlog(1, "%s: no udev information", pp->dev);
> > return 1;
> > }
> > @@ -1669,7 +1668,7 @@ get_uid (struct path * pp, int path_state)
> > int retrigger;
> >
> > if (pp->uid_attribute) {
> > - len = get_udev_uid(pp, pp->uid_attribute);
> > + len = get_udev_uid(pp, pp->uid_attribute, udev);
> > origin = "udev";
> > if (len <= 0)
> > condlog(1,
> > @@ -1798,7 +1797,7 @@ pathinfo (struct path *pp, struct config *conf, int mask)
> > }
> >
> > if ((mask & DI_WWID) && !strlen(pp->wwid)) {
> > - get_uid(pp, path_state);
> > + get_uid(pp, path_state, pp->udev);
> > if (!strlen(pp->wwid)) {
> > pp->initialized = INIT_MISSING_UDEV;
> > pp->tick = conf->retrigger_delay;
> > diff --git a/libmultipath/discovery.h b/libmultipath/discovery.h
> > index 0f5b1e6..176eac1 100644
> > --- a/libmultipath/discovery.h
> > +++ b/libmultipath/discovery.h
> > @@ -49,6 +49,7 @@ ssize_t sysfs_get_vpd (struct udev_device * udev, int pg, unsigned char * buff,
> > size_t len);
> > int sysfs_get_asymmetric_access_state(struct path *pp,
> > char *buff, int buflen);
> > +int get_uid(struct path * pp, int path_state, struct udev_device *udev);
> >
> > /*
> > * discovery bitmask
> > diff --git a/libmultipath/structs.h b/libmultipath/structs.h
> > index 3a716d8..58508f6 100644
> > --- a/libmultipath/structs.h
> > +++ b/libmultipath/structs.h
> > @@ -217,6 +217,7 @@ struct path {
> > int fd;
> > int initialized;
> > int retriggers;
> > + int wwid_changed;
> >
> > /* configlet pointers */
> > struct hwentry * hwe;
> > diff --git a/multipathd/main.c b/multipathd/main.c
> > index dbb4554..bb96cca 100644
> > --- a/multipathd/main.c
> > +++ b/multipathd/main.c
> > @@ -958,6 +958,12 @@ uev_update_path (struct uevent *uev, struct vectors * vecs)
> > {
> > int ro, retval = 0;
> > struct path * pp;
> > + struct config *conf;
> > + int disable_changed_wwids;
> > +
> > + conf = get_multipath_config();
> > + disable_changed_wwids = conf->disable_changed_wwids;
> > + put_multipath_config(conf);
> >
> > ro = uevent_get_disk_ro(uev);
> >
> > @@ -969,6 +975,25 @@ uev_update_path (struct uevent *uev, struct vectors * vecs)
> > if (pp) {
> > struct multipath *mpp = pp->mpp;
> >
> > + if (disable_changed_wwids &&
> > + (strlen(pp->wwid) || pp->wwid_changed)) {
> > + char wwid[WWID_SIZE];
> > +
> > + strcpy(wwid, pp->wwid);
> > + get_uid(pp, pp->state, uev->udev);
> > + if (strcmp(wwid, pp->wwid) != 0) {
> > + condlog(0, "%s: path wwid changed from '%s' to '%s'. disallowing", uev->kernel, wwid, pp->wwid);
> > + strcpy(pp->wwid, wwid);
> > + if (!pp->wwid_changed) {
> > + pp->wwid_changed = 1;
> > + pp->tick = 1;
> > + dm_fail_path(pp->mpp->alias, pp->dev_t);
> > + }
> > + goto out;
> > + } else
> > + pp->wwid_changed = 0;
> > + }
> > +
> > if (pp->initialized == INIT_REQUESTED_UDEV)
> > retval = uev_add_path(uev, vecs);
> > else if (mpp && ro >= 0) {
> > @@ -983,6 +1008,7 @@ uev_update_path (struct uevent *uev, struct vectors * vecs)
> > }
> > }
> > }
> > +out:
> > lock_cleanup_pop(vecs->lock);
> > if (!pp)
> > condlog(0, "%s: spurious uevent, path not found", uev->kernel);
> > @@ -1509,6 +1535,12 @@ check_path (struct vectors * vecs, struct path * pp, int ticks)
> > } else
> > checker_clear_message(&pp->checker);
> >
> > + if (pp->wwid_changed) {
> > + condlog(2, "%s: path wwid has changed. Refusing to use",
> > + pp->dev);
> > + newstate = PATH_DOWN;
> > + }
> > +
> > if (newstate == PATH_WILD || newstate == PATH_UNCHECKED) {
> > condlog(2, "%s: unusable path", pp->dev);
> > conf = get_multipath_config();
> >
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