md: factor out set_in_sync()

Three separate places in md.c check if the number of active
writes is zero and, if so, sets mddev->in_sync.

There are a few differences, but there shouldn't be:
- it is always appropriate to notify the change in
  sysfs_state, and there is no need to do this outside a
  spin-locked region.
- we never need to check ->recovery_cp.  The state of resync
  is not relevant for whether there are any pending writes
  or not (which is what ->in_sync reports).

So create set_in_sync() which does the correct tests and
makes the correct changes, and call this in all three
places.

Any behaviour changes here a minor and cosmetic.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 41f766ab824af1bf7e1427921aebc32ac625167b..5951dea75abac7e36a9da875a74a6b34272a3ba7 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2252,6 +2252,21 @@ static void export_array(struct mddev *mddev)
        mddev->major_version = 0;
 }
 
+static bool set_in_sync(struct mddev *mddev)
+{
+       WARN_ON_ONCE(!spin_is_locked(&mddev->lock));
+       if (atomic_read(&mddev->writes_pending) == 0) {
+               if (mddev->in_sync == 0) {
+                       mddev->in_sync = 1;
+                       set_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags);
+                       sysfs_notify_dirent_safe(mddev->sysfs_state);
+               }
+       }
+       if (mddev->safemode == 1)
+               mddev->safemode = 0;
+       return mddev->in_sync;
+}
+
 static void sync_sbs(struct mddev *mddev, int nospares)
 {
        /* Update each superblock (in-memory image), but
@@ -4024,7 +4039,7 @@ static int restart_array(struct mddev *mddev);
 static ssize_t
 array_state_store(struct mddev *mddev, const char *buf, size_t len)
 {
-       int err;
+       int err = 0;
        enum array_state st = match_word(buf, array_states);
 
        if (mddev->pers && (st == active || st == clean) && mddev->ro != 1) {
@@ -4037,18 +4052,9 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len)
                        clear_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags);
                        md_wakeup_thread(mddev->thread);
                        wake_up(&mddev->sb_wait);
-                       err = 0;
                } else /* st == clean */ {
                        restart_array(mddev);
-                       if (atomic_read(&mddev->writes_pending) == 0) {
-                               if (mddev->in_sync == 0) {
-                                       mddev->in_sync = 1;
-                                       if (mddev->safemode == 1)
-                                               mddev->safemode = 0;
-                                       set_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags);
-                               }
-                               err = 0;
-                       } else
+                       if (!set_in_sync(mddev))
                                err = -EBUSY;
                }
                if (!err)
@@ -4106,15 +4112,7 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len)
                        if (err)
                                break;
                        spin_lock(&mddev->lock);
-                       if (atomic_read(&mddev->writes_pending) == 0) {
-                               if (mddev->in_sync == 0) {
-                                       mddev->in_sync = 1;
-                                       if (mddev->safemode == 1)
-                                               mddev->safemode = 0;
-                                       set_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags);
-                               }
-                               err = 0;
-                       } else
+                       if (!set_in_sync(mddev))
                                err = -EBUSY;
                        spin_unlock(&mddev->lock);
                } else
@@ -8582,22 +8580,10 @@ void md_check_recovery(struct mddev *mddev)
                        }
                }
 
-               if (!mddev->external) {
-                       int did_change = 0;
+               if (!mddev->external && !mddev->in_sync) {
                        spin_lock(&mddev->lock);
-                       if (mddev->safemode &&
-                           !atomic_read(&mddev->writes_pending) &&
-                           !mddev->in_sync &&
-                           mddev->recovery_cp == MaxSector) {
-                               mddev->in_sync = 1;
-                               did_change = 1;
-                               set_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags);
-                       }
-                       if (mddev->safemode == 1)
-                               mddev->safemode = 0;
+                       set_in_sync(mddev);
                        spin_unlock(&mddev->lock);
-                       if (did_change)
-                               sysfs_notify_dirent_safe(mddev->sysfs_state);
                }
 
                if (mddev->sb_flags)