libdevmapper has the 'quirk' that DM_DEVICE_CREATE is translated
internally into a create/load/resume sequence, and the associated
cookie will wait for the last 'resume' to complete.
However, DM_DEVICE_RELOAD has no such translation, so if there
is a cookie assigned to it the caller _cannot_ wait for it,
as the cookie will only ever be completed upon the next
DM_DEVICE_RESUME.
multipathd already has some provisions for that (but even there
the cookie handling is dodgy), but 'multipath -r' doesn't know
about this.
So to avoid any future irritations this patch updates the
dm_addmad_reload() call to handle the cookie correctly,
and removes the special handling from multipathd.

Signed-off-by: Hannes Reinecke <h...@suse.de>
---
 libmultipath/configure.c | 16 ++++------------
 libmultipath/devmapper.c | 41 ++++++++++++++++++++++++++++-------------
 libmultipath/devmapper.h |  2 +-
 3 files changed, 33 insertions(+), 26 deletions(-)

diff --git a/libmultipath/configure.c b/libmultipath/configure.c
index affd1d5..ed6cf98 100644
--- a/libmultipath/configure.c
+++ b/libmultipath/configure.c
@@ -625,16 +625,11 @@ domap (struct multipath * mpp, char * params)
                break;
 
        case ACT_RELOAD:
-               r = dm_addmap_reload(mpp, params);
-               if (r)
-                       r = dm_simplecmd_noflush(DM_DEVICE_RESUME, mpp->alias,
-                                                0, MPATH_UDEV_RELOAD_FLAG);
+               r = dm_addmap_reload(mpp, params, 0);
                break;
 
        case ACT_RESIZE:
-               r = dm_addmap_reload(mpp, params);
-               if (r)
-                       r = dm_simplecmd_flush(DM_DEVICE_RESUME, mpp->alias, 0);
+               r = dm_addmap_reload(mpp, params, 1);
                break;
 
        case ACT_RENAME:
@@ -643,11 +638,8 @@ domap (struct multipath * mpp, char * params)
 
        case ACT_RENAME2:
                r = dm_rename(mpp->alias_old, mpp->alias);
-               if (r) {
-                       r = dm_addmap_reload(mpp, params);
-                       if (r)
-                               r = dm_simplecmd_noflush(DM_DEVICE_RESUME, 
mpp->alias, 0, MPATH_UDEV_RELOAD_FLAG);
-               }
+               if (r)
+                       r = dm_addmap_reload(mpp, params, 0);
                break;
 
        default:
diff --git a/libmultipath/devmapper.c b/libmultipath/devmapper.c
index 9facbb9..04dcb72 100644
--- a/libmultipath/devmapper.c
+++ b/libmultipath/devmapper.c
@@ -315,12 +315,13 @@ dm_addmap (int task, const char *target, struct multipath 
*mpp,
        if (mpp->attribute_flags & (1 << ATTR_GID) &&
            !dm_task_set_gid(dmt, mpp->gid))
                goto freeout;
-       condlog(4, "%s: addmap [0 %llu %s %s]", mpp->alias, mpp->size,
+       condlog(4, "%s: %s [0 %llu %s %s]", mpp->alias,
+               task == DM_DEVICE_RELOAD ? "reload" : "addmap", mpp->size,
                target, params);
 
        dm_task_no_open_count(dmt);
 
-       if (task == DM_DEVICE_CREATE &&
+       if (cookie &&
            !dm_task_set_cookie(dmt, cookie,
                                DM_UDEV_DISABLE_LIBRARY_FALLBACK)) {
                dm_udev_complete(*cookie);
@@ -328,10 +329,11 @@ dm_addmap (int task, const char *target, struct multipath 
*mpp,
        }
        r = dm_task_run (dmt);
 
-       if (task == DM_DEVICE_CREATE) {
-               if (!r)
+       if (cookie) {
+               if (!r || task != DM_DEVICE_CREATE) {
+                       /* Do not wait on a cookie for DM_DEVICE_RELOAD */
                        dm_udev_complete(*cookie);
-               else
+               } else
                        dm_udev_wait(*cookie);
        }
        freeout:
@@ -377,16 +379,29 @@ dm_addmap_create (struct multipath *mpp, char * params) {
 #define ADDMAP_RO 1
 
 extern int
-dm_addmap_reload (struct multipath *mpp, char *params) {
+dm_addmap_reload (struct multipath *mpp, char *params, int flush) {
+       int r;
        uint32_t cookie = 0;
+       uint16_t udev_flags = flush ? 0 : MPATH_UDEV_RELOAD_FLAG;
 
-       if (dm_addmap(DM_DEVICE_RELOAD, TGT_MPATH, mpp, params,
-                     ADDMAP_RW, &cookie))
-               return 1;
-       if (errno != EROFS)
-               return 0;
-       return dm_addmap(DM_DEVICE_RELOAD, TGT_MPATH, mpp, params,
-                        ADDMAP_RO, &cookie);
+       /*
+        * DM_DEVICE_RELOAD cannot wait on a cookie, as
+        * the cookie will only ever be released after an
+        * DM_DEVICE_RESUME. So call DM_DEVICE_RESUME
+        * after each DM_DEVICE_RELOAD.
+        */
+       r = dm_addmap(DM_DEVICE_RELOAD, TGT_MPATH, mpp, params,
+                     ADDMAP_RW, &cookie);
+       if (!r) {
+               if (errno != EROFS)
+                       return 0;
+               r = dm_addmap(DM_DEVICE_RELOAD, TGT_MPATH, mpp, params,
+                             ADDMAP_RO, &cookie);
+       }
+       if (r)
+               r = dm_simplecmd(DM_DEVICE_RESUME, mpp->alias, flush,
+                                udev_flags, 0, &cookie);
+       return r;
 }
 
 extern int
diff --git a/libmultipath/devmapper.h b/libmultipath/devmapper.h
index 8dd0963..97f3742 100644
--- a/libmultipath/devmapper.h
+++ b/libmultipath/devmapper.h
@@ -18,7 +18,7 @@ int dm_drv_version (unsigned int * version, char * str);
 int dm_simplecmd_flush (int, const char *, uint16_t);
 int dm_simplecmd_noflush (int, const char *, int, uint16_t);
 int dm_addmap_create (struct multipath *mpp, char *params);
-int dm_addmap_reload (struct multipath *mpp, char *params);
+int dm_addmap_reload (struct multipath *mpp, char *params, int flush);
 int dm_map_present (const char *);
 int dm_get_map(const char *, unsigned long long *, char *);
 int dm_get_status(char *, char *);
-- 
2.6.6

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