From: tang.junhui <[email protected]> These uevents are going to be merged: 1) uevents come from paths and 2) uevents type is same and 3) uevents type is addition or deletion and 4) uevents wwid is same.
Change-Id: I05ee057391c092aa0c5f989b7a4f9cb550bb4d98 Signed-off-by: tang.junhui <[email protected]> --- libmultipath/uevent.c | 125 +++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 114 insertions(+), 11 deletions(-) diff --git a/libmultipath/uevent.c b/libmultipath/uevent.c index b0b05e9..114068c 100644 --- a/libmultipath/uevent.c +++ b/libmultipath/uevent.c @@ -85,6 +85,20 @@ struct uevent * alloc_uevent (void) return uev; } +void +uevq_cleanup(struct list_head *tmpq) +{ + struct uevent *uev, *tmp; + + list_for_each_entry_safe(uev, tmp, tmpq, node) { + list_del_init(&uev->node); + + if (uev->udev) + udev_device_unref(uev->udev); + FREE(uev); + } +} + bool uevent_can_discard(char *devpath, char *kernel) { @@ -125,6 +139,103 @@ uevent_can_discard(char *devpath, char *kernel) return false; } +bool +merge_need_stop(struct uevent *earlier, struct uevent *later) +{ + /* + * dm uevent do not try to merge with left uevents + */ + if (!strncmp(later->kernel, "dm-", 3)) + return true; + + /* + * we can not make a jugement without wwid, + * so it is sensible to stop merging + */ + if (!earlier->wwid || !later->wwid) + return true; + /* + * uevents merging stoped + * when we meet an opposite action uevent from the same LUN to AVOID + * "add path1 |remove path1 |add path2 |remove path2 |add path3" + * to merge as "remove path1, path2" and "add path1, path2, path3" + * OR + * "remove path1 |add path1 |remove path2 |add path2 |remove path3" + * to merge as "add path1, path2" and "remove path1, path2, path3" + * SO + * when we meet a non-change uevent from the same LUN + * with the same wwid and different action + * it would be better to stop merging. + */ + if (!strcmp(earlier->wwid, later->wwid) && + strcmp(earlier->action, later->action) && + strcmp(earlier->action, "change") && + strcmp(later->action, "change")) + return true; + + return false; +} + +bool +uevent_can_merge(struct uevent *earlier, struct uevent *later) +{ + /* merge paths uevents + * whose wwids exsit and are same + * and actions are same, + * and actions are addition or deletion + */ + if (earlier->wwid && later->wwid && + !strcmp(earlier->wwid, later->wwid) && + !strcmp(earlier->action, later->action) && + strncmp(earlier->action, "change", 6) && + strncmp(earlier->kernel, "dm-", 3)) { + return true; + } + + return false; +} + +void +uevent_merge(struct uevent *later, struct list_head *tmpq) +{ + struct uevent *earlier, *temp; + /* + * compare the uevent with earlier uevents + */ + list_for_some_entry_reverse(earlier, &later->node, tmpq, node) { +next_earlier_node: + if (merge_need_stop(earlier, later)) + break; + /* + * try to merge earlier uevents to the later uevent + */ + if (uevent_can_merge(earlier, later)) { + condlog(3, "merged uevent: %s-%s-%s with uevent: %s-%s-%s", + earlier->action, earlier->kernel, earlier->wwid, + later->action, later->kernel, later->wwid); + temp = earlier; + + earlier = list_entry(earlier->node.prev, typeof(struct uevent), node); + list_move(&temp->node, &later->merge_node); + + if (earlier == list_entry(tmpq, typeof(struct uevent), node)) + break; + else + goto next_earlier_node; + } + } +} + +void +merge_uevq(struct list_head *tmpq) +{ + struct uevent *later; + + list_for_each_entry_reverse(later, tmpq, node) { + uevent_merge(later, tmpq); + } +} + void service_uevq(struct list_head *tmpq) { @@ -136,6 +247,8 @@ service_uevq(struct list_head *tmpq) if (my_uev_trigger && my_uev_trigger(uev, my_trigger_data)) condlog(0, "uevent trigger error"); + uevq_cleanup(&uev->merge_node); + if (uev->udev) udev_device_unref(uev->udev); FREE(uev); @@ -150,17 +263,6 @@ static void uevent_cleanup(void *arg) udev_unref(udev); } -void -uevq_cleanup(struct list_head *tmpq) -{ - struct uevent *uev, *tmp; - - list_for_each_entry_safe(uev, tmp, tmpq, node) { - list_del_init(&uev->node); - FREE(uev); - } -} - /* * Service the uevent queue. */ @@ -189,6 +291,7 @@ int uevent_dispatch(int (*uev_trigger)(struct uevent *, void * trigger_data), pthread_mutex_unlock(uevq_lockp); if (!my_uev_trigger) break; + merge_uevq(&uevq_tmp); service_uevq(&uevq_tmp); } condlog(3, "Terminating uev service queue"); -- 2.8.1.windows.1 -- dm-devel mailing list [email protected] https://www.redhat.com/mailman/listinfo/dm-devel
