Hi Christophe,




OK, I'll post it later.




regards,

Tang Junhui













原始邮件



发件人： ＜christophe.varoqui@opensvc.com＞
收件人： ＜bmarzins@redhat.com＞
抄送人：唐文俊10144149唐军辉10074136张凯10072500 ＜dm-devel@redhat.com＞ ＜bart.vanassche@sandisk.com＞ ＜mwilck@suse.com＞
日 期 ：2017年02月27日 14:22
主 题 ：Re: [dm-devel] [PATCH] multipath-tools: improve processing efficiency for addition and deletion of multipath devices






Hi Junhui,


It seems I did not receive the patch version Acked by Ben,Can you rebase and post please ?


Thanks.




On Thu, Feb 16, 2017 at 5:27 PM, Benjamin Marzinski ＜bmarzins@redhat.com＞ wrote:
On Thu, Feb 16, 2017 at 02:54:01PM +0800, tang.junhui@zte.com.cn wrote:
 ＞ From: "tang.junhui" ＜tang.junhui@zte.com.cn＞
 
 ACK
 
 Thanks for all your work on this.
 -Ben
 


 ＞
 ＞ Change-Id: I3f81a55fff389f991f915927000b281d7e263cc5
 ＞ Signed-off-by: tang.junhui ＜tang.junhui@zte.com.cn＞
 ＞
 ＞ This patch used to improve processing efficiency for addition and deletion
 ＞ of multipath devices.
 ＞
 ＞ This patch is tested pass by ZTE multipath automatic testing system.
 ＞ The modification reduces the system consumption(such as CPU) and shortens
 ＞ the processing time obviously in scene of massive multipath devices
 ＞ addition or deletion.
 ＞
 ＞ The main processing flow of code is:
 ＞ 1) add uid_attrs configuration in the defaults section:
 ＞    It is configured udev attribute which providing a unique path identifier
 ＞    for corresponding type of path devices. If this field is configured and
 ＞    matched with type of device, it would override any other methods providing
 ＞    for device unique identifier in config file, and it would activate merging
 ＞    uevents according to the identifier to promote effiecncy in processing
 ＞    uevents. Tt has no default value, so defaultly only uevents filtering
 ＞    works, and uevents merging does not works, if users want to identify path
 ＞    by udev attribute and to activate merging uevents for SCSI and DAS device,
 ＞    they can set it's value as:
 ＞    "sd:ID_SERIAL dasd:ID_UID"
 ＞ 2) uevents accumulation in uevents burst scene:
 ＞    wait one seconds for more uevents in uevent_listen() in uevents burst
 ＞    situations
 ＞ 3) uevents preparing, filtering and merging:
 ＞    discard unuse uevents and fetch path idendifier from uevents
 ＞    filter uevents
 ＞    merge uevents.
 ＞ 4) uevents proccessing:
 ＞    proccess the merged uevents in uev-＞merge_node list without calling
 ＞    domap()
 ＞    proccess the last uevents uev with calling domap().
 ＞ ---
 ＞  libmultipath/config.c      |   3 +
 ＞  libmultipath/config.h      |   1 +
 ＞  libmultipath/dict.c        |   3 +
 ＞  libmultipath/discovery.c   |   5 +-
 ＞  libmultipath/discovery.h   |   2 +-
 ＞  libmultipath/list.h        |  41 ++++++
 ＞  libmultipath/propsel.c     |   7 +
 ＞  libmultipath/uevent.c      | 320 +++++++++++++++++++++++++++++++++++++++++++--
 ＞  libmultipath/uevent.h      |   2 +
 ＞  libmultipath/util.c        |  42 ++++++
 ＞  libmultipath/util.h        |   1 +
 ＞  multipath/multipath.conf.5 |  18 +++
 ＞  multipathd/cli_handlers.c  |   4 +-
 ＞  multipathd/main.c          |  93 +++++--------
 ＞  multipathd/main.h          |   4 +-
 ＞  15 files changed, 471 insertions(+), 75 deletions(-)
 ＞
 ＞ diff --git a/libmultipath/config.c b/libmultipath/config.c
 ＞ index 15ddbd8..765e91d 100644
 ＞ --- a/libmultipath/config.c
 ＞ +++ b/libmultipath/config.c
 ＞ @@ -488,6 +488,9 @@ free_config (struct config * conf)
 ＞       if (conf-＞uid_attribute)
 ＞               FREE(conf-＞uid_attribute)
 ＞
 ＞ +     if (conf-＞uid_attrs)
 ＞ +             FREE(conf-＞uid_attrs)
 ＞ +
 ＞       if (conf-＞getuid)
 ＞               FREE(conf-＞getuid)
 ＞
 ＞ diff --git a/libmultipath/config.h b/libmultipath/config.h
 ＞ index 9670020..ab85930 100644
 ＞ --- a/libmultipath/config.h
 ＞ +++ b/libmultipath/config.h
 ＞ @@ -153,6 +153,7 @@ struct config {
 ＞
 ＞       char * multipath_dir
 ＞       char * selector
 ＞ +     char * uid_attrs
 ＞       char * uid_attribute
 ＞       char * getuid
 ＞       char * features
 ＞ diff --git a/libmultipath/dict.c b/libmultipath/dict.c
 ＞ index dc21846..0a531d1 100644
 ＞ --- a/libmultipath/dict.c
 ＞ +++ b/libmultipath/dict.c
 ＞ @@ -249,6 +249,8 @@ declare_ovr_snprint(selector, print_str)
 ＞  declare_mp_handler(selector, set_str)
 ＞  declare_mp_snprint(selector, print_str)
 ＞
 ＞ +declare_def_handler(uid_attrs, set_str)
 ＞ +declare_def_snprint(uid_attrs, print_str)
 ＞  declare_def_handler(uid_attribute, set_str)
 ＞  declare_def_snprint_defstr(uid_attribute, print_str, DEFAULT_UID_ATTRIBUTE)
 ＞  declare_ovr_handler(uid_attribute, set_str)
 ＞ @@ -1367,6 +1369,7 @@ init_keywords(vector keywords)
 ＞       install_keyword("multipath_dir", &def_multipath_dir_handler, &snprint_def_multipath_dir)
 ＞       install_keyword("path_selector", &def_selector_handler, &snprint_def_selector)
 ＞       install_keyword("path_grouping_policy", &def_pgpolicy_handler, &snprint_def_pgpolicy)
 ＞ +     install_keyword("uid_attrs", &def_uid_attrs_handler, &snprint_def_uid_attrs)
 ＞       install_keyword("uid_attribute", &def_uid_attribute_handler, &snprint_def_uid_attribute)
 ＞       install_keyword("getuid_callout", &def_getuid_handler, &snprint_def_getuid)
 ＞       install_keyword("prio", &def_prio_name_handler, &snprint_def_prio_name)
 ＞ diff --git a/libmultipath/discovery.c b/libmultipath/discovery.c
 ＞ index d1aec31..14904f2 100644
 ＞ --- a/libmultipath/discovery.c
 ＞ +++ b/libmultipath/discovery.c
 ＞ @@ -33,7 +33,7 @@
 ＞
 ＞  int
 ＞  alloc_path_with_pathinfo (struct config *conf, struct udev_device *udevice,
 ＞ -                       int flag, struct path **pp_ptr)
 ＞ +                       char *wwid, int flag, struct path **pp_ptr)
 ＞  {
 ＞       int err = PATHINFO_FAILED
 ＞       struct path * pp
 ＞ @@ -51,6 +51,9 @@ alloc_path_with_pathinfo (struct config *conf, struct udev_device *udevice,
 ＞       if (!pp)
 ＞               return PATHINFO_FAILED
 ＞
 ＞ +     if(wwid)
 ＞ +             strncpy(pp-＞wwid, wwid, sizeof(pp-＞wwid))
 ＞ +
 ＞       if (safe_sprintf(pp-＞dev, "%s", devname)) {
 ＞               condlog(0, "pp-＞dev too small")
 ＞       } else {
 ＞ diff --git a/libmultipath/discovery.h b/libmultipath/discovery.h
 ＞ index 3039268..d16a69a 100644
 ＞ --- a/libmultipath/discovery.h
 ＞ +++ b/libmultipath/discovery.h
 ＞ @@ -37,7 +37,7 @@ int path_offline (struct path *)
 ＞  int get_state (struct path * pp, struct config * conf, int daemon)
 ＞  int pathinfo (struct path * pp, struct config * conf, int mask)
 ＞  int alloc_path_with_pathinfo (struct config *conf, struct udev_device *udevice,
 ＞ -                           int flag, struct path **pp_ptr)
 ＞ +                           char *wwid, int flag, struct path **pp_ptr)
 ＞  int store_pathinfo (vector pathvec, struct config *conf,
 ＞                   struct udev_device *udevice, int flag,
 ＞                   struct path **pp_ptr)
 ＞ diff --git a/libmultipath/list.h b/libmultipath/list.h
 ＞ index ceaa381..2b1dcf3 100644
 ＞ --- a/libmultipath/list.h
 ＞ +++ b/libmultipath/list.h
 ＞ @@ -317,4 +317,45 @@ static inline void list_splice_tail_init(struct list_head *list,
 ＞            &pos-＞member != (head)                                    \
 ＞            pos = n, n = list_entry(n-＞member.next, typeof(*n), member))
 ＞
 ＞ +/**
 ＞ + * list_for_each_entry_reverse_safe - iterate backwards over list of given type safe against removal of list entry
 ＞ + * @pos:     the type * to use as a loop counter.
 ＞ + * @n:               another type * to use as temporary storage
 ＞ + * @head:    the head for your list.
 ＞ + * @member:  the name of the list_struct within the struct.
 ＞ + */
 ＞ +#define list_for_each_entry_reverse_safe(pos, n, head, member)          \
 ＞ +     for (pos = list_entry((head)-＞prev, typeof(*pos), member),      \
 ＞ +              n = list_entry(pos-＞member.prev, typeof(*pos), member)\
 ＞ +          &pos-＞member != (head)                                    \
 ＞ +          pos = n, n = list_entry(n-＞member.prev, typeof(*n), member))
 ＞ +
 ＞ +/**
 ＞ + * list_for_some_entry_safe - iterate list from the given begin node to the given end node safe against removal of list entry
 ＞ + * @pos:     the type * to use as a loop counter.
 ＞ + * @n:               another type * to use as temporary storage
 ＞ + * @from:    the begin node of the iteration.
 ＞ + * @to:              the end node of the iteration.
 ＞ + * @member:  the name of the list_struct within the struct.
 ＞ + */
 ＞ +#define list_for_some_entry_safe(pos, n, from, to, member)              \
 ＞ +     for (pos = list_entry((from)-＞next, typeof(*pos), member),      \
 ＞ +          n = list_entry(pos-＞member.next, typeof(*pos), member)    \
 ＞ +          &pos-＞member != (to)                                      \
 ＞ +          pos = n, n = list_entry(n-＞member.next, typeof(*n), member))
 ＞ +
 ＞ +/**
 ＞ + * list_for_some_entry_reverse_safe - iterate backwards list from the given begin node to the given end node safe against removal of list entry
 ＞ + * @pos:     the type * to use as a loop counter.
 ＞ + * @n:               another type * to use as temporary storage
 ＞ + * @from:    the begin node of the iteration.
 ＞ + * @to:              the end node of the iteration.
 ＞ + * @member:  the name of the list_struct within the struct.
 ＞ + */
 ＞ +#define list_for_some_entry_reverse_safe(pos, n, from, to, member)      \
 ＞ +     for (pos = list_entry((from)-＞prev, typeof(*pos), member),      \
 ＞ +          n = list_entry(pos-＞member.prev, typeof(*pos), member)    \
 ＞ +          &pos-＞member != (to)                                      \
 ＞ +          pos = n, n = list_entry(n-＞member.prev, typeof(*n), member))
 ＞ +
 ＞  #endif /* _LIST_H */
 ＞ diff --git a/libmultipath/propsel.c b/libmultipath/propsel.c
 ＞ index c0bc616..c47bd08 100644
 ＞ --- a/libmultipath/propsel.c
 ＞ +++ b/libmultipath/propsel.c
 ＞ @@ -18,6 +18,7 @@
 ＞  #include "prio.h"
 ＞  #include "discovery.h"
 ＞  #include "dict.h"
 ＞ +#include "util.h"
 ＞  #include "prioritizers/alua_rtpg.h"
 ＞  #include ＜inttypes.h＞
 ＞
 ＞ @@ -339,6 +340,12 @@ int select_getuid(struct config *conf, struct path *pp)
 ＞  {
 ＞       char *origin
 ＞
 ＞ +     pp-＞uid_attribute = parse_uid_attribute_by_attrs(conf-＞uid_attrs, pp-＞dev)
 ＞ +     if (pp-＞uid_attribute) {
 ＞ +             origin = "(setting: multipath.conf defaults section)"
 ＞ +             goto out
 ＞ +     }
 ＞ +
 ＞       pp_set_ovr(getuid)
 ＞       pp_set_ovr(uid_attribute)
 ＞       pp_set_hwe(getuid)
 ＞ diff --git a/libmultipath/uevent.c b/libmultipath/uevent.c
 ＞ index 7edcce1..6e2527b 100644
 ＞ --- a/libmultipath/uevent.c
 ＞ +++ b/libmultipath/uevent.c
 ＞ @@ -24,6 +24,7 @@
 ＞
 ＞  #include ＜unistd.h＞
 ＞  #include ＜stdio.h＞
 ＞ +#include ＜stdbool.h＞
 ＞  #include ＜errno.h＞
 ＞  #include ＜stdlib.h＞
 ＞  #include ＜stddef.h＞
 ＞ @@ -38,6 +39,7 @@
 ＞  #include ＜linux/netlink.h＞
 ＞  #include ＜pthread.h＞
 ＞  #include ＜sys/mman.h＞
 ＞ +#include ＜sys/time.h＞
 ＞  #include ＜libudev.h＞
 ＞  #include ＜errno.h＞
 ＞
 ＞ @@ -46,6 +48,14 @@
 ＞  #include "list.h"
 ＞  #include "uevent.h"
 ＞  #include "vector.h"
 ＞ +#include "structs.h"
 ＞ +#include "util.h"
 ＞ +#include "config.h"
 ＞ +#include "blacklist.h"
 ＞ +
 ＞ +#define MAX_ACCUMULATION_COUNT 2048
 ＞ +#define MAX_ACCUMULATION_TIME 30*1000
 ＞ +#define MIN_BURST_SPEED 10
 ＞
 ＞  typedef int (uev_trigger)(struct uevent *, void * trigger_data)
 ＞
 ＞ @@ -72,48 +82,301 @@ struct uevent * alloc_uevent (void)
 ＞  {
 ＞       struct uevent *uev = MALLOC(sizeof(struct uevent))
 ＞
 ＞ -     if (uev)
 ＞ +     if (uev) {
 ＞               INIT_LIST_HEAD(&uev-＞node)
 ＞ +             INIT_LIST_HEAD(&uev-＞merge_node)
 ＞ +     }
 ＞
 ＞       return uev
 ＞  }
 ＞
 ＞  void
 ＞ -service_uevq(struct list_head *tmpq)
 ＞ +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 (my_uev_trigger && my_uev_trigger(uev, my_trigger_data))
 ＞ -                     condlog(0, "uevent trigger error")
 ＞ -
 ＞               if (uev-＞udev)
 ＞                       udev_device_unref(uev-＞udev)
 ＞               FREE(uev)
 ＞       }
 ＞  }
 ＞
 ＞ -static void uevent_cleanup(void *arg)
 ＞ +void
 ＞ +uevent_get_wwid(struct uevent *uev)
 ＞  {
 ＞ -     struct udev *udev = arg
 ＞ +     int i
 ＞ +     char *uid_attribute
 ＞ +     struct config * conf
 ＞
 ＞ -     condlog(3, "Releasing uevent_listen() resources")
 ＞ -     udev_unref(udev)
 ＞ +     conf = get_multipath_config()
 ＞ +     uid_attribute = parse_uid_attribute_by_attrs(conf-＞uid_attrs, uev-＞kernel)
 ＞ +     put_multipath_config(conf)
 ＞ +
 ＞ +     if (!uid_attribute)
 ＞ +             return
 ＞ +
 ＞ +     for (i = 0 uev-＞envp[i] != NULL i++) {
 ＞ +             if (!strncmp(uev-＞envp[i], uid_attribute, strlen(uid_attribute)) &&
 ＞ +                 strlen(uev-＞envp[i]) ＞ strlen(uid_attribute) &&
 ＞ +                 uev-＞envp[i][strlen(uid_attribute)] == '=') {
 ＞ +                     uev-＞wwid = uev-＞envp[i] + strlen(uid_attribute) + 1
 ＞ +                     break
 ＞ +             }
 ＞ +     }
 ＞ +     free(uid_attribute)
 ＞ +}
 ＞ +
 ＞ +bool
 ＞ +uevent_need_merge(void)
 ＞ +{
 ＞ +     struct config * conf
 ＞ +     bool need_merge = false
 ＞ +
 ＞ +     conf = get_multipath_config()
 ＞ +     if (conf-＞uid_attrs)
 ＞ +             need_merge = true
 ＞ +     put_multipath_config(conf)
 ＞ +
 ＞ +     return need_merge
 ＞ +}
 ＞ +
 ＞ +bool
 ＞ +uevent_can_discard(struct uevent *uev)
 ＞ +{
 ＞ +     char *tmp
 ＞ +     char a[11], b[11]
 ＞ +     struct config * conf
 ＞ +
 ＞ +     /*
 ＞ +      * keep only block devices, discard partitions
 ＞ +      */
 ＞ +     tmp = strstr(uev-＞devpath, "/block/")
 ＞ +     if (tmp == NULL){
 ＞ +             condlog(4, "no /block/ in '%s'", uev-＞devpath)
 ＞ +             return true
 ＞ +     }
 ＞ +     if (sscanf(tmp, "/block/%10s", a) != 1 ||
 ＞ +         sscanf(tmp, "/block/%10[^/]/%10s", a, b) == 2) {
 ＞ +             condlog(4, "discard event on %s", uev-＞devpath)
 ＞ +             return true
 ＞ +     }
 ＞ +
 ＞ +     /*
 ＞ +      * do not filter dm devices by devnode
 ＞ +      */
 ＞ +     if (!strncmp(uev-＞kernel, "dm-", 3))
 ＞ +             return false
 ＞ +     /*
 ＞ +      * filter paths devices by devnode
 ＞ +      */
 ＞ +     conf = get_multipath_config()
 ＞ +     if (filter_devnode(conf-＞blist_devnode, conf-＞elist_devnode,
 ＞ +                        uev-＞kernel) ＞ 0) {
 ＞ +             put_multipath_config(conf)
 ＞ +             return true
 ＞ +     }
 ＞ +     put_multipath_config(conf)
 ＞ +
 ＞ +     return false
 ＞ +}
 ＞ +
 ＞ +bool
 ＞ +uevent_can_filter(struct uevent *earlier, struct uevent *later)
 ＞ +{
 ＞ +
 ＞ +     /*
 ＞ +      * filter earlier uvents if path has removed later. Eg:
 ＞ +      * "add path1 |chang path1 |add path2 |remove path1"
 ＞ +      * can filter as:
 ＞ +      * "add path2 |remove path1"
 ＞ +      * uevents "add path1" and "chang path1" are filtered out
 ＞ +      */
 ＞ +     if (!strcmp(earlier-＞kernel, later-＞kernel) &&
 ＞ +             !strcmp(later-＞action, "remove") &&
 ＞ +             strncmp(later-＞kernel, "dm-", 3)) {
 ＞ +             return true
 ＞ +     }
 ＞ +
 ＞ +     /*
 ＞ +      * filter change uvents if add uevents exist. Eg:
 ＞ +      * "change path1| add path1 |add path2"
 ＞ +      * can filter as:
 ＞ +      * "add path1 |add path2"
 ＞ +      * uevent "chang path1" is filtered out
 ＞ +      */
 ＞ +     if (!strcmp(earlier-＞kernel, later-＞kernel) &&
 ＞ +             !strcmp(earlier-＞action, "change") &&
 ＞ +             !strcmp(later-＞action, "add") &&
 ＞ +             strncmp(later-＞kernel, "dm-", 3)) {
 ＞ +             return true
 ＞ +     }
 ＞ +
 ＞ +     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
 ＞ -uevq_cleanup(struct list_head *tmpq)
 ＞ +uevent_prepare(struct list_head *tmpq)
 ＞ +{
 ＞ +     struct uevent *uev, *tmp
 ＞ +
 ＞ +     list_for_each_entry_reverse_safe(uev, tmp, tmpq, node) {
 ＞ +             if (uevent_can_discard(uev)) {
 ＞ +                     list_del_init(&uev-＞node)
 ＞ +                     if (uev-＞udev)
 ＞ +                             udev_device_unref(uev-＞udev)
 ＞ +                     FREE(uev)
 ＞ +                     continue
 ＞ +             }
 ＞ +
 ＞ +             if (strncmp(uev-＞kernel, "dm-", 3) &&
 ＞ +                 uevent_need_merge())
 ＞ +                     uevent_get_wwid(uev)
 ＞ +     }
 ＞ +}
 ＞ +
 ＞ +void
 ＞ +uevent_filter(struct uevent *later, struct list_head *tmpq)
 ＞ +{
 ＞ +     struct uevent *earlier, *tmp
 ＞ +
 ＞ +     list_for_some_entry_reverse_safe(earlier, tmp, &later-＞node, tmpq, node) {
 ＞ +             /*
 ＞ +              * filter unnessary earlier uevents
 ＞ +              * by the later uevent
 ＞ +              */
 ＞ +             if (uevent_can_filter(earlier, later)) {
 ＞ +                     condlog(2, "uevent: %s-%s has filtered by uevent: %s-%s",
 ＞ +                             earlier-＞kernel, earlier-＞action,
 ＞ +                             later-＞kernel, later-＞action)
 ＞ +
 ＞ +                     list_del_init(&earlier-＞node)
 ＞ +                     if (earlier-＞udev)
 ＞ +                             udev_device_unref(earlier-＞udev)
 ＞ +                     FREE(earlier)
 ＞ +             }
 ＞ +     }
 ＞ +}
 ＞ +
 ＞ +void
 ＞ +uevent_merge(struct uevent *later, struct list_head *tmpq)
 ＞ +{
 ＞ +     struct uevent *earlier, *tmp
 ＞ +
 ＞ +     list_for_some_entry_reverse_safe(earlier, tmp, &later-＞node, tmpq, node) {
 ＞ +             if (merge_need_stop(earlier, later))
 ＞ +                     break
 ＞ +             /*
 ＞ +              * merge earlier uevents to the later uevent
 ＞ +              */
 ＞ +             if (uevent_can_merge(earlier, later)) {
 ＞ +                     condlog(2, "merged uevent: %s-%s-%s with uevent: %s-%s-%s",
 ＞ +                             earlier-＞action, earlier-＞kernel, earlier-＞wwid,
 ＞ +                             later-＞action, later-＞kernel, later-＞wwid)
 ＞ +
 ＞ +                     list_move(&earlier-＞node, &later-＞merge_node)
 ＞ +             }
 ＞ +     }
 ＞ +}
 ＞ +
 ＞ +void
 ＞ +merge_uevq(struct list_head *tmpq)
 ＞ +{
 ＞ +     struct uevent *later
 ＞ +
 ＞ +     uevent_prepare(tmpq)
 ＞ +     list_for_each_entry_reverse(later, tmpq, node) {
 ＞ +             uevent_filter(later, tmpq)
 ＞ +             if(uevent_need_merge())
 ＞ +                     uevent_merge(later, tmpq)
 ＞ +     }
 ＞ +}
 ＞ +
 ＞ +void
 ＞ +service_uevq(struct list_head *tmpq)
 ＞  {
 ＞       struct uevent *uev, *tmp
 ＞
 ＞       list_for_each_entry_safe(uev, tmp, tmpq, node) {
 ＞               list_del_init(&uev-＞node)
 ＞ +
 ＞ +             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)
 ＞       }
 ＞  }
 ＞
 ＞ +static void uevent_cleanup(void *arg)
 ＞ +{
 ＞ +     struct udev *udev = arg
 ＞ +
 ＞ +     condlog(3, "Releasing uevent_listen() resources")
 ＞ +     udev_unref(udev)
 ＞ +}
 ＞ +
 ＞  /*
 ＞   * Service the uevent queue.
 ＞   */
 ＞ @@ -142,6 +405,7 @@ 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")
 ＞ @@ -442,11 +706,43 @@ struct uevent *uevent_from_udev_device(struct udev_device *dev)
 ＞       return uev
 ＞  }
 ＞
 ＞ +bool uevent_burst(struct timeval *start_time, int events)
 ＞ +{
 ＞ +     struct timeval diff_time, end_time
 ＞ +     unsigned long speed
 ＞ +     unsigned long eclipse_ms
 ＞ +
 ＞ +     if(events ＞ MAX_ACCUMULATION_COUNT) {
 ＞ +             condlog(2, "burst got %u uevents, too much uevents, stopped", events)
 ＞ +             return false
 ＞ +     }
 ＞ +
 ＞ +     gettimeofday(&end_time, NULL)
 ＞ +     timersub(&end_time, start_time, &diff_time)
 ＞ +
 ＞ +     eclipse_ms = diff_time.tv_sec * 1000 + diff_time.tv_usec / 1000
 ＞ +
 ＞ +     if (eclipse_ms == 0)
 ＞ +             return true
 ＞ +
 ＞ +     if (eclipse_ms ＞ MAX_ACCUMULATION_TIME) {
 ＞ +             condlog(2, "burst continued %lu ms, too long time, stopped", eclipse_ms)
 ＞ +             return false
 ＞ +     }
 ＞ +
 ＞ +     speed = (events * 1000) / eclipse_ms
 ＞ +     if (speed ＞ MIN_BURST_SPEED)
 ＞ +             return true
 ＞ +
 ＞ +     return false
 ＞ +}
 ＞ +
 ＞  int uevent_listen(struct udev *udev)
 ＞  {
 ＞       int err = 2
 ＞       struct udev_monitor *monitor = NULL
 ＞       int fd, socket_flags, events
 ＞ +     struct timeval start_time
 ＞       int need_failback = 1
 ＞       int timeout = 30
 ＞       LIST_HEAD(uevlisten_tmp)
 ＞ @@ -500,6 +796,7 @@ int uevent_listen(struct udev *udev)
 ＞       }
 ＞
 ＞       events = 0
 ＞ +     gettimeofday(&start_time, NULL)
 ＞       while (1) {
 ＞               struct uevent *uev
 ＞               struct udev_device *dev
 ＞ @@ -514,7 +811,7 @@ int uevent_listen(struct udev *udev)
 ＞               errno = 0
 ＞               fdcount = poll(&ev_poll, 1, poll_timeout)
 ＞               if (fdcount && ev_poll.revents & POLLIN) {
 ＞ -                     timeout = 0
 ＞ +                     timeout = uevent_burst(&start_time, events + 1) ? 1 : 0
 ＞                       dev = udev_monitor_receive_device(monitor)
 ＞                       if (!dev) {
 ＞                               condlog(0, "failed getting udev device")
 ＞ @@ -547,6 +844,7 @@ int uevent_listen(struct udev *udev)
 ＞                       pthread_mutex_unlock(uevq_lockp)
 ＞                       events = 0
 ＞               }
 ＞ +             gettimeofday(&start_time, NULL)
 ＞               timeout = 30
 ＞       }
 ＞       need_failback = 0
 ＞ diff --git a/libmultipath/uevent.h b/libmultipath/uevent.h
 ＞ index 9d22dcd..61a4207 100644
 ＞ --- a/libmultipath/uevent.h
 ＞ +++ b/libmultipath/uevent.h
 ＞ @@ -17,11 +17,13 @@ struct udev
 ＞
 ＞  struct uevent {
 ＞       struct list_head node
 ＞ +     struct list_head merge_node
 ＞       struct udev_device *udev
 ＞       char buffer[HOTPLUG_BUFFER_SIZE + OBJECT_SIZE]
 ＞       char *devpath
 ＞       char *action
 ＞       char *kernel
 ＞ +     char *wwid
 ＞       unsigned long seqnum
 ＞       char *envp[HOTPLUG_NUM_ENVP]
 ＞  }
 ＞ diff --git a/libmultipath/util.c b/libmultipath/util.c
 ＞ index 03a5738..e1e83cf 100644
 ＞ --- a/libmultipath/util.c
 ＞ +++ b/libmultipath/util.c
 ＞ @@ -261,6 +261,48 @@ dev_t parse_devt(const char *dev_t)
 ＞       return makedev(maj, min)
 ＞  }
 ＞
 ＞ +char *parse_uid_attribute_by_attrs(char *uid_attrs, char *path_dev)
 ＞ +{
 ＞ +     char *uid_attribute
 ＞ +     char *uid_attr_record
 ＞ +     char *dev
 ＞ +     char *attr
 ＞ +     char *tmp
 ＞ +     int  count
 ＞ +
 ＞ +     if(!uid_attrs || !path_dev)
 ＞ +             return NULL
 ＞ +
 ＞ +     count = get_word(uid_attrs, &uid_attr_record)
 ＞ +     while (uid_attr_record) {
 ＞ +             tmp = strrchr(uid_attr_record, ':')
 ＞ +             if (!tmp) {
 ＞ +                     free(uid_attr_record)
 ＞ +                     if (!count)
 ＞ +                             break
 ＞ +                     uid_attrs += count
 ＞ +                     count = get_word(uid_attrs, &uid_attr_record)
 ＞ +                     continue
 ＞ +             }
 ＞ +             dev = uid_attr_record
 ＞ +             attr = tmp + 1
 ＞ +             *tmp = '\0'
 ＞ +
 ＞ +             if(!strncmp(path_dev, dev, strlen(dev))) {
 ＞ +                     uid_attribute = STRDUP(attr)
 ＞ +                     free(uid_attr_record)
 ＞ +                     return uid_attribute
 ＞ +             }
 ＞ +
 ＞ +             free(uid_attr_record)
 ＞ +             if (!count)
 ＞ +                     break
 ＞ +             uid_attrs += count
 ＞ +             count = get_word(uid_attrs, &uid_attr_record)
 ＞ +     }
 ＞ +     return NULL
 ＞ +}
 ＞ +
 ＞  void
 ＞  setup_thread_attr(pthread_attr_t *attr, size_t stacksize, int detached)
 ＞  {
 ＞ diff --git a/libmultipath/util.h b/libmultipath/util.h
 ＞ index f3b37ee..793f2b7 100644
 ＞ --- a/libmultipath/util.h
 ＞ +++ b/libmultipath/util.h
 ＞ @@ -12,6 +12,7 @@ size_t strlcat(char *dst, const char *src, size_t size)
 ＞  int devt2devname (char *, int, char *)
 ＞  dev_t parse_devt(const char *dev_t)
 ＞  char *convert_dev(char *dev, int is_path_device)
 ＞ +char *parse_uid_attribute_by_attrs(char *uid_attrs, char *path_dev)
 ＞  void setup_thread_attr(pthread_attr_t *attr, size_t stacksize, int detached)
 ＞
 ＞  #define safe_sprintf(var, format, args...)   \
 ＞ diff --git a/multipath/multipath.conf.5 b/multipath/multipath.conf.5
 ＞ index 36589f5..63c63c2 100644
 ＞ --- a/multipath/multipath.conf.5
 ＞ +++ b/multipath/multipath.conf.5
 ＞ @@ -209,6 +209,24 @@ The default is: \fBfailover\fR
 ＞  .
 ＞  .
 ＞  .TP
 ＞ +.B uid_attrs
 ＞ +The udev attribute providing a unique path identifier for corresponding
 ＞ +type of path devices. If this field is configured and matched with type
 ＞ +of device, it would override any other methods providing for device
 ＞ +unique identifier in config file, and it would activate merging uevents
 ＞ +according to the identifier to promote effiecncy in processing uevents.
 ＞ +Tt has no default value, if you want to identify path by udev attribute
 ＞ +and to activate merging uevents for SCSI and DAS device, you can set
 ＞ +it's value as:
 ＞ +.RS
 ＞ +.TP
 ＞ +\fBuid_attrs "sd:ID_SERIAL dasd:ID_UID"\fR
 ＞ +.TP
 ＞ +The default is: \fB＜unset＞\fR
 ＞ +.RE
 ＞ +.
 ＞ +.
 ＞ +.TP
 ＞  .B uid_attribute
 ＞  The udev attribute providing a unique path identifier.
 ＞  .RS
 ＞ diff --git a/multipathd/cli_handlers.c b/multipathd/cli_handlers.c
 ＞ index b0eeca6..12f85de 100644
 ＞ --- a/multipathd/cli_handlers.c
 ＞ +++ b/multipathd/cli_handlers.c
 ＞ @@ -670,7 +670,7 @@ cli_add_path (void * v, char ** reply, int * len, void * data)
 ＞               pp-＞checkint = conf-＞checkint
 ＞       }
 ＞       put_multipath_config(conf)
 ＞ -     return ev_add_path(pp, vecs)
 ＞ +     return ev_add_path(pp, vecs, 1)
 ＞  blacklisted:
 ＞       *reply = strdup("blacklisted\n")
 ＞       *len = strlen(*reply) + 1
 ＞ @@ -692,7 +692,7 @@ cli_del_path (void * v, char ** reply, int * len, void * data)
 ＞               condlog(0, "%s: path already removed", param)
 ＞               return 1
 ＞       }
 ＞ -     return ev_remove_path(pp, vecs)
 ＞ +     return ev_remove_path(pp, vecs, 1)
 ＞  }
 ＞
 ＞  int
 ＞ diff --git a/multipathd/main.c b/multipathd/main.c
 ＞ index adc3258..e513f7d 100644
 ＞ --- a/multipathd/main.c
 ＞ +++ b/multipathd/main.c
 ＞ @@ -608,7 +608,7 @@ ev_remove_map (char * devname, char * alias, int minor, struct vectors * vecs)
 ＞  }
 ＞
 ＞  static int
 ＞ -uev_add_path (struct uevent *uev, struct vectors * vecs)
 ＞ +uev_add_path (struct uevent *uev, struct vectors * vecs, int need_do_map)
 ＞  {
 ＞       struct path *pp
 ＞       int ret = 0, i
 ＞ @@ -641,7 +641,7 @@ uev_add_path (struct uevent *uev, struct vectors * vecs)
 ＞                                    DI_ALL | DI_BLACKLIST)
 ＞                       put_multipath_config(conf)
 ＞                       if (r == PATHINFO_OK)
 ＞ -                             ret = ev_add_path(pp, vecs)
 ＞ +                             ret = ev_add_path(pp, vecs, need_do_map)
 ＞                       else if (r == PATHINFO_SKIPPED) {
 ＞                               condlog(3, "%s: remove blacklisted path",
 ＞                                       uev-＞kernel)
 ＞ @@ -665,7 +665,7 @@ uev_add_path (struct uevent *uev, struct vectors * vecs)
 ＞        */
 ＞       conf = get_multipath_config()
 ＞       ret = alloc_path_with_pathinfo(conf, uev-＞udev,
 ＞ -                                    DI_ALL, &pp)
 ＞ +                                    uev-＞wwid, DI_ALL, &pp)
 ＞       put_multipath_config(conf)
 ＞       if (!pp) {
 ＞               if (ret == PATHINFO_SKIPPED)
 ＞ @@ -681,7 +681,7 @@ uev_add_path (struct uevent *uev, struct vectors * vecs)
 ＞               conf = get_multipath_config()
 ＞               pp-＞checkint = conf-＞checkint
 ＞               put_multipath_config(conf)
 ＞ -             ret = ev_add_path(pp, vecs)
 ＞ +             ret = ev_add_path(pp, vecs, need_do_map)
 ＞       } else {
 ＞               condlog(0, "%s: failed to store path info, "
 ＞                       "dropping event",
 ＞ @@ -699,7 +699,7 @@ uev_add_path (struct uevent *uev, struct vectors * vecs)
 ＞   * 1: error
 ＞   */
 ＞  int
 ＞ -ev_add_path (struct path * pp, struct vectors * vecs)
 ＞ +ev_add_path (struct path * pp, struct vectors * vecs, int need_do_map)
 ＞  {
 ＞       struct multipath * mpp
 ＞       char params[PARAMS_SIZE] = {0}
 ＞ @@ -767,6 +767,13 @@ rescan:
 ＞       /* persistent reservation check*/
 ＞       mpath_pr_event_handle(pp)
 ＞
 ＞ +     if (!need_do_map)
 ＞ +             return 0
 ＞ +
 ＞ +     if (!dm_map_present(mpp-＞alias)) {
 ＞ +             mpp-＞action = ACT_CREATE
 ＞ +             start_waiter = 1
 ＞ +     }
 ＞       /*
 ＞        * push the map to the device-mapper
 ＞        */
 ＞ @@ -833,7 +840,7 @@ fail:
 ＞  }
 ＞
 ＞  static int
 ＞ -uev_remove_path (struct uevent *uev, struct vectors * vecs)
 ＞ +uev_remove_path (struct uevent *uev, struct vectors * vecs, int need_do_map)
 ＞  {
 ＞       struct path *pp
 ＞       int ret
 ＞ @@ -844,7 +851,7 @@ uev_remove_path (struct uevent *uev, struct vectors * vecs)
 ＞       pthread_testcancel()
 ＞       pp = find_path_by_dev(vecs-＞pathvec, uev-＞kernel)
 ＞       if (pp)
 ＞ -             ret = ev_remove_path(pp, vecs)
 ＞ +             ret = ev_remove_path(pp, vecs, need_do_map)
 ＞       lock_cleanup_pop(vecs-＞lock)
 ＞       if (!pp) {
 ＞               /* Not an error path might have been purged earlier */
 ＞ @@ -855,7 +862,7 @@ uev_remove_path (struct uevent *uev, struct vectors * vecs)
 ＞  }
 ＞
 ＞  int
 ＞ -ev_remove_path (struct path *pp, struct vectors * vecs)
 ＞ +ev_remove_path (struct path *pp, struct vectors * vecs, int need_do_map)
 ＞  {
 ＞       struct multipath * mpp
 ＞       int i, retval = 0
 ＞ @@ -918,6 +925,8 @@ ev_remove_path (struct path *pp, struct vectors * vecs)
 ＞                       goto out
 ＞               }
 ＞
 ＞ +             if (!need_do_map)
 ＞ +                     goto out
 ＞               /*
 ＞                * reload the map
 ＞                */
 ＞ @@ -995,7 +1004,7 @@ uev_update_path (struct uevent *uev, struct vectors * vecs)
 ＞               }
 ＞
 ＞               if (pp-＞initialized == INIT_REQUESTED_UDEV)
 ＞ -                     retval = uev_add_path(uev, vecs)
 ＞ +                     retval = uev_add_path(uev, vecs, 1)
 ＞               else if (mpp && ro ＞= 0) {
 ＞                       condlog(2, "%s: update path write_protect to '%d' (uevent)", uev-＞kernel, ro)
 ＞
 ＞ @@ -1016,7 +1025,7 @@ out:
 ＞                       int flag = DI_SYSFS | DI_WWID
 ＞
 ＞                       conf = get_multipath_config()
 ＞ -                     retval = alloc_path_with_pathinfo(conf, uev-＞udev, flag, NULL)
 ＞ +                     retval = alloc_path_with_pathinfo(conf, uev-＞udev, uev-＞wwid, flag, NULL)
 ＞                       put_multipath_config(conf)
 ＞
 ＞                       if (retval == PATHINFO_SKIPPED) {
 ＞ @@ -1077,40 +1086,15 @@ uxsock_trigger (char * str, char ** reply, int * len, void * trigger_data)
 ＞       return r
 ＞  }
 ＞
 ＞ -static int
 ＞ -uev_discard(char * devpath)
 ＞ -{
 ＞ -     char *tmp
 ＞ -     char a[11], b[11]
 ＞ -
 ＞ -     /*
 ＞ -      * keep only block devices, discard partitions
 ＞ -      */
 ＞ -     tmp = strstr(devpath, "/block/")
 ＞ -     if (tmp == NULL){
 ＞ -             condlog(4, "no /block/ in '%s'", devpath)
 ＞ -             return 1
 ＞ -     }
 ＞ -     if (sscanf(tmp, "/block/%10s", a) != 1 ||
 ＞ -         sscanf(tmp, "/block/%10[^/]/%10s", a, b) == 2) {
 ＞ -             condlog(4, "discard event on %s", devpath)
 ＞ -             return 1
 ＞ -     }
 ＞ -     return 0
 ＞ -}
 ＞ -
 ＞  int
 ＞  uev_trigger (struct uevent * uev, void * trigger_data)
 ＞  {
 ＞       int r = 0
 ＞       struct vectors * vecs
 ＞ -     struct config *conf
 ＞ +     struct uevent *merge_uev, *tmp
 ＞
 ＞       vecs = (struct vectors *)trigger_data
 ＞
 ＞ -     if (uev_discard(uev-＞devpath))
 ＞ -             return 0
 ＞ -
 ＞       pthread_cleanup_push(config_cleanup, NULL)
 ＞       pthread_mutex_lock(&config_lock)
 ＞       if (running_state != DAEMON_IDLE &&
 ＞ @@ -1139,28 +1123,21 @@ uev_trigger (struct uevent * uev, void * trigger_data)
 ＞       }
 ＞
 ＞       /*
 ＞ -      * path add/remove event
 ＞ +      * path add/remove/change event, add/remove maybe merged
 ＞        */
 ＞ -     conf = get_multipath_config()
 ＞ -     if (filter_devnode(conf-＞blist_devnode, conf-＞elist_devnode,
 ＞ -                        uev-＞kernel) ＞ 0) {
 ＞ -             put_multipath_config(conf)
 ＞ -             goto out
 ＞ +     list_for_each_entry_safe(merge_uev, tmp, &uev-＞merge_node, node) {
 ＞ +             if (!strncmp(merge_uev-＞action, "add", 3))
 ＞ +                     r += uev_add_path(merge_uev, vecs, 0)
 ＞ +             if (!strncmp(merge_uev-＞action, "remove", 6))
 ＞ +                     r += uev_remove_path(merge_uev, vecs, 0)
 ＞       }
 ＞ -     put_multipath_config(conf)
 ＞
 ＞ -     if (!strncmp(uev-＞action, "add", 3)) {
 ＞ -             r = uev_add_path(uev, vecs)
 ＞ -             goto out
 ＞ -     }
 ＞ -     if (!strncmp(uev-＞action, "remove", 6)) {
 ＞ -             r = uev_remove_path(uev, vecs)
 ＞ -             goto out
 ＞ -     }
 ＞ -     if (!strncmp(uev-＞action, "change", 6)) {
 ＞ -             r = uev_update_path(uev, vecs)
 ＞ -             goto out
 ＞ -     }
 ＞ +     if (!strncmp(uev-＞action, "add", 3))
 ＞ +             r += uev_add_path(uev, vecs, 1)
 ＞ +     if (!strncmp(uev-＞action, "remove", 6))
 ＞ +             r += uev_remove_path(uev, vecs, 1)
 ＞ +     if (!strncmp(uev-＞action, "change", 6))
 ＞ +             r += uev_update_path(uev, vecs)
 ＞
 ＞  out:
 ＞       return r
 ＞ @@ -1570,7 +1547,7 @@ check_path (struct vectors * vecs, struct path * pp, int ticks)
 ＞                       conf = get_multipath_config()
 ＞                       ret = pathinfo(pp, conf, DI_ALL | DI_BLACKLIST)
 ＞                       if (ret == PATHINFO_OK) {
 ＞ -                             ev_add_path(pp, vecs)
 ＞ +                             ev_add_path(pp, vecs, 1)
 ＞                               pp-＞tick = 1
 ＞                       } else if (ret == PATHINFO_SKIPPED) {
 ＞                               put_multipath_config(conf)
 ＞ @@ -1686,7 +1663,7 @@ check_path (struct vectors * vecs, struct path * pp, int ticks)
 ＞               }
 ＞               if (!disable_reinstate && reinstate_path(pp, add_active)) {
 ＞                       condlog(3, "%s: reload map", pp-＞dev)
 ＞ -                     ev_add_path(pp, vecs)
 ＞ +                     ev_add_path(pp, vecs, 1)
 ＞                       pp-＞tick = 1
 ＞                       return 0
 ＞               }
 ＞ @@ -1709,7 +1686,7 @@ check_path (struct vectors * vecs, struct path * pp, int ticks)
 ＞                       /* Clear IO errors */
 ＞                       if (reinstate_path(pp, 0)) {
 ＞                               condlog(3, "%s: reload map", pp-＞dev)
 ＞ -                             ev_add_path(pp, vecs)
 ＞ +                             ev_add_path(pp, vecs, 1)
 ＞                               pp-＞tick = 1
 ＞                               return 0
 ＞                       }
 ＞ diff --git a/multipathd/main.h b/multipathd/main.h
 ＞ index f72580d..094b04f 100644
 ＞ --- a/multipathd/main.h
 ＞ +++ b/multipathd/main.h
 ＞ @@ -22,8 +22,8 @@ void exit_daemon(void)
 ＞  const char * daemon_status(void)
 ＞  int need_to_delay_reconfig (struct vectors *)
 ＞  int reconfigure (struct vectors *)
 ＞ -int ev_add_path (struct path *, struct vectors *)
 ＞ -int ev_remove_path (struct path *, struct vectors *)
 ＞ +int ev_add_path (struct path *, struct vectors *, int)
 ＞ +int ev_remove_path (struct path *, struct vectors *, int)
 ＞  int ev_add_map (char *, char *, struct vectors *)
 ＞  int ev_remove_map (char *, char *, int, struct vectors *)
 ＞  void sync_map_state (struct multipath *)
 ＞ --
 ＞ 2.8.1.windows.1
 ＞