1 files changed, 32 insertions, 9 deletions

diff --git a/drivers/md/dm-log-userspace-base.c b/drivers/md/dm-log-userspace-base.c
index 1c25ad3d02a2..767adf300fa5 100644
--- a/drivers/md/dm-log-userspace-base.c
+++ b/drivers/md/dm-log-userspace-base.c
@@ -37,8 +37,15 @@ struct log_c {
          */
         uint64_t in_sync_hint;
 
+        /*
+         * Mark and clear requests are held until a flush is issued
+         * so that we can group, and thereby limit, the amount of
+         * network traffic between kernel and userspace.  The 'flush_lock'
+         * is used to protect these lists.
+         */
         spinlock_t flush_lock;
-        struct list_head flush_list;  /* only for clear and mark requests */
+        struct list_head mark_list;
+        struct list_head clear_list;
 };
 
 static mempool_t *flush_entry_pool;
@@ -169,7 +176,8 @@ static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 
         strncpy(lc->uuid, argv[0], DM_UUID_LEN);
         spin_lock_init(&lc->flush_lock);
-        INIT_LIST_HEAD(&lc->flush_list);
+        INIT_LIST_HEAD(&lc->mark_list);
+        INIT_LIST_HEAD(&lc->clear_list);
 
         str_size = build_constructor_string(ti, argc - 1, argv + 1, &ctr_str);
         if (str_size < 0) {
@@ -362,14 +370,16 @@ static int userspace_flush(struct dm_dirty_log *log)
         int r = 0;
         unsigned long flags;
         struct log_c *lc = log->context;
-        LIST_HEAD(flush_list);
+        LIST_HEAD(mark_list);
+        LIST_HEAD(clear_list);
         struct flush_entry *fe, *tmp_fe;
 
         spin_lock_irqsave(&lc->flush_lock, flags);
-        list_splice_init(&lc->flush_list, &flush_list);
+        list_splice_init(&lc->mark_list, &mark_list);
+        list_splice_init(&lc->clear_list, &clear_list);
         spin_unlock_irqrestore(&lc->flush_lock, flags);
 
-        if (list_empty(&flush_list))
+        if (list_empty(&mark_list) && list_empty(&clear_list))
                 return 0;
 
         /*
@@ -379,7 +389,16 @@ static int userspace_flush(struct dm_dirty_log *log)
          * do it one by one.
          */
 
-        list_for_each_entry(fe, &flush_list, list) {
+        list_for_each_entry(fe, &mark_list, list) {
+                r = userspace_do_request(lc, lc->uuid, fe->type,
+                                         (char *)&fe->region,
+                                         sizeof(fe->region),
+                                         NULL, NULL);
+                if (r)
+                        goto fail;
+        }
+
+        list_for_each_entry(fe, &clear_list, list) {
                 r = userspace_do_request(lc, lc->uuid, fe->type,
                                          (char *)&fe->region,
                                          sizeof(fe->region),
@@ -397,7 +416,11 @@ fail:
          * Calling code will receive an error and will know that
          * the log facility has failed.
          */
-        list_for_each_entry_safe(fe, tmp_fe, &flush_list, list) {
+        list_for_each_entry_safe(fe, tmp_fe, &mark_list, list) {
+                list_del(&fe->list);
+                mempool_free(fe, flush_entry_pool);
+        }
+        list_for_each_entry_safe(fe, tmp_fe, &clear_list, list) {
                 list_del(&fe->list);
                 mempool_free(fe, flush_entry_pool);
         }
@@ -427,7 +450,7 @@ static void userspace_mark_region(struct dm_dirty_log *log, region_t region)
         spin_lock_irqsave(&lc->flush_lock, flags);
         fe->type = DM_ULOG_MARK_REGION;
         fe->region = region;
-        list_add(&fe->list, &lc->flush_list);
+        list_add(&fe->list, &lc->mark_list);
         spin_unlock_irqrestore(&lc->flush_lock, flags);
 
         return;
@@ -464,7 +487,7 @@ static void userspace_clear_region(struct dm_dirty_log *log, region_t region)
         spin_lock_irqsave(&lc->flush_lock, flags);
         fe->type = DM_ULOG_CLEAR_REGION;
         fe->region = region;
-        list_add(&fe->list, &lc->flush_list);
+        list_add(&fe->list, &lc->clear_list);
         spin_unlock_irqrestore(&lc->flush_lock, flags);
 
         return;