3 files changed, 36 insertions, 6 deletions

diff --git a/Documentation/md.txt b/Documentation/md.txt
index dca97ba4944a..c05bfb55659e 100644
--- a/Documentation/md.txt
+++ b/Documentation/md.txt
@@ -386,6 +386,12 @@ also have
         'check' and 'repair' will start the appropriate process
            providing the current state is 'idle'.
 
+      This file responds to select/poll.  Any important change in the value
+      triggers a poll event.  Sometimes the value will briefly be
+      "recover" if a recovery seems to be needed, but cannot be
+      achieved. In that case, the transition to "recover" isn't
+      notified, but the transition away is.
+
    mismatch_count
       When performing 'check' and 'repair', and possibly when
       performing 'resync', md will count the number of errors that are
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 5b9d4fe4e6e4..c26dcad8a3ac 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -169,7 +169,6 @@ void md_new_event(mddev_t *mddev)
 {
         atomic_inc(&md_event_count);
         wake_up(&md_event_waiters);
-        sysfs_notify(&mddev->kobj, NULL, "sync_action");
 }
 EXPORT_SYMBOL_GPL(md_new_event);
 
@@ -2936,7 +2935,7 @@ action_show(mddev_t *mddev, char *page)
                                 type = "check";
                         else
                                 type = "repair";
-                } else
+                } else if (test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
                         type = "recover";
         }
         return sprintf(page, "%s\n", type);
@@ -2958,9 +2957,12 @@ action_store(mddev_t *mddev, const char *page, size_t len)
         } else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
                    test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
                 return -EBUSY;
-        else if (cmd_match(page, "resync") || cmd_match(page, "recover"))
+        else if (cmd_match(page, "resync"))
+                set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+        else if (cmd_match(page, "recover")) {
+                set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
-        else if (cmd_match(page, "reshape")) {
+        } else if (cmd_match(page, "reshape")) {
                 int err;
                 if (mddev->pers->start_reshape == NULL)
                         return -EINVAL;
@@ -2977,6 +2979,7 @@ action_store(mddev_t *mddev, const char *page, size_t len)
         }
         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
         md_wakeup_thread(mddev->thread);
+        sysfs_notify(&mddev->kobj, NULL, "sync_action");
         return len;
 }
 
@@ -3682,6 +3685,7 @@ static int do_md_run(mddev_t * mddev)
         mddev->changed = 1;
         md_new_event(mddev);
         sysfs_notify(&mddev->kobj, NULL, "array_state");
+        sysfs_notify(&mddev->kobj, NULL, "sync_action");
         kobject_uevent(&mddev->gendisk->dev.kobj, KOBJ_CHANGE);
         return 0;
 }
@@ -4252,6 +4256,8 @@ static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
                         export_rdev(rdev);
 
                 md_update_sb(mddev, 1);
+                if (mddev->degraded)
+                        set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
                 md_wakeup_thread(mddev->thread);
                 return err;
@@ -5105,6 +5111,8 @@ void md_error(mddev_t *mddev, mdk_rdev_t *rdev)
         if (!mddev->pers->error_handler)
                 return;
         mddev->pers->error_handler(mddev,rdev);
+        if (mddev->degraded)
+                set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
         md_wakeup_thread(mddev->thread);
@@ -6055,13 +6063,18 @@ void md_check_recovery(mddev_t *mddev)
                         mddev->recovery = 0;
                         /* flag recovery needed just to double check */
                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+                        sysfs_notify(&mddev->kobj, NULL, "sync_action");
                         md_new_event(mddev);
                         goto unlock;
                 }
+                /* Set RUNNING before clearing NEEDED to avoid
+                 * any transients in the value of "sync_action".
+                 */
+                set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
+                clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
                 /* Clear some bits that don't mean anything, but
                  * might be left set
                  */
-                clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
                 clear_bit(MD_RECOVERY_INTR, &mddev->recovery);
                 clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
 
@@ -6079,17 +6092,19 @@ void md_check_recovery(mddev_t *mddev)
                                 /* Cannot proceed */
                                 goto unlock;
                         set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
+                        clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
                 } else if ((spares = remove_and_add_spares(mddev))) {
                         clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
                         clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
+                        set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
                 } else if (mddev->recovery_cp < MaxSector) {
                         set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
+                        clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
                 } else if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
                         /* nothing to be done ... */
                         goto unlock;
 
                 if (mddev->pers->sync_request) {
-                        set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
                         if (spares && mddev->bitmap && ! mddev->bitmap->file) {
                                 /* We are adding a device or devices to an array
                                  * which has the bitmap stored on all devices.
@@ -6108,9 +6123,16 @@ void md_check_recovery(mddev_t *mddev)
                                 mddev->recovery = 0;
                         } else
                                 md_wakeup_thread(mddev->sync_thread);
+                        sysfs_notify(&mddev->kobj, NULL, "sync_action");
                         md_new_event(mddev);
                 }
         unlock:
+                if (!mddev->sync_thread) {
+                        clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
+                        if (test_and_clear_bit(MD_RECOVERY_RECOVER,
+                                               &mddev->recovery))
+                                sysfs_notify(&mddev->kobj, NULL, "sync_action");
+                }
                 mddev_unlock(mddev);
         }
 }
diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h
index 780e0613e6d5..62aa9c9a6ddc 100644
--- a/include/linux/raid/md_k.h
+++ b/include/linux/raid/md_k.h
@@ -188,6 +188,7 @@ struct mddev_s
          * NEEDED:   we might need to start a resync/recover
          * RUNNING:  a thread is running, or about to be started
          * SYNC:     actually doing a resync, not a recovery
+         * RECOVER:  doing recovery, or need to try it.
          * INTR:     resync needs to be aborted for some reason
          * DONE:     thread is done and is waiting to be reaped
          * REQUEST:  user-space has requested a sync (used with SYNC)
@@ -198,6 +199,7 @@ struct mddev_s
          */
 #define MD_RECOVERY_RUNNING     0
 #define MD_RECOVERY_SYNC        1
+#define MD_RECOVERY_RECOVER     2
 #define MD_RECOVERY_INTR        3
 #define MD_RECOVERY_DONE        4
 #define MD_RECOVERY_NEEDED      5