md: use sysfs_notify_dirent to notify changes to md/array_state

Now that we have sysfs_notify_dirent, use it to notify changes
to md/array_state.
As sysfs_notify_dirent can be called in atomic context, we can
remove the delayed notify and the MD_NOTIFY_ARRAY_STATE flag.

Signed-off-by: NeilBrown <neilb@suse.de>

2 files changed, 20 insertions, 15 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index aaa3d465de4e..feea72dc4b69 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -222,6 +222,9 @@ static void mddev_put(mddev_t *mddev)
                 list_del(&mddev->all_mddevs);
                 spin_unlock(&all_mddevs_lock);
                 blk_cleanup_queue(mddev->queue);
+                if (mddev->sysfs_state)
+                        sysfs_put(mddev->sysfs_state);
+                mddev->sysfs_state = NULL;
                 kobject_put(&mddev->kobj);
         } else
                 spin_unlock(&all_mddevs_lock);
@@ -2770,7 +2773,7 @@ array_state_store(mddev_t *mddev, const char *buf, size_t len)
         if (err)
                 return err;
         else {
-                sysfs_notify(&mddev->kobj, NULL, "array_state");
+                sysfs_notify_dirent(mddev->sysfs_state);
                 return len;
         }
 }
@@ -3465,8 +3468,10 @@ static struct kobject *md_probe(dev_t dev, int *part, void *data)
         if (error)
                 printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
                        disk->disk_name);
-        else
+        else {
                 kobject_uevent(&mddev->kobj, KOBJ_ADD);
+                mddev->sysfs_state = sysfs_get_dirent(mddev->kobj.sd, "array_state");
+        }
         return NULL;
 }
 
@@ -3477,7 +3482,7 @@ static void md_safemode_timeout(unsigned long data)
         if (!atomic_read(&mddev->writes_pending)) {
                 mddev->safemode = 1;
                 if (mddev->external)
-                        set_bit(MD_NOTIFY_ARRAY_STATE, &mddev->flags);
+                        sysfs_notify_dirent(mddev->sysfs_state);
         }
         md_wakeup_thread(mddev->thread);
 }
@@ -3740,7 +3745,7 @@ static int do_md_run(mddev_t * mddev)
 
         mddev->changed = 1;
         md_new_event(mddev);
-        sysfs_notify(&mddev->kobj, NULL, "array_state");
+        sysfs_notify_dirent(mddev->sysfs_state);
         sysfs_notify(&mddev->kobj, NULL, "sync_action");
         sysfs_notify(&mddev->kobj, NULL, "degraded");
         kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
@@ -3767,7 +3772,7 @@ static int restart_array(mddev_t *mddev)
         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
         md_wakeup_thread(mddev->thread);
         md_wakeup_thread(mddev->sync_thread);
-        sysfs_notify(&mddev->kobj, NULL, "array_state");
+        sysfs_notify_dirent(mddev->sysfs_state);
         return 0;
 }
 
@@ -3847,7 +3852,7 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
                         module_put(mddev->pers->owner);
                         mddev->pers = NULL;
                         /* tell userspace to handle 'inactive' */
-                        sysfs_notify(&mddev->kobj, NULL, "array_state");
+                        sysfs_notify_dirent(mddev->sysfs_state);
 
                         set_capacity(disk, 0);
                         mddev->changed = 1;
@@ -3933,7 +3938,7 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
                         mdname(mddev));
         err = 0;
         md_new_event(mddev);
-        sysfs_notify(&mddev->kobj, NULL, "array_state");
+        sysfs_notify_dirent(mddev->sysfs_state);
 out:
         return err;
 }
@@ -4938,7 +4943,7 @@ static int md_ioctl(struct inode *inode, struct file *file,
         if (_IOC_TYPE(cmd) == MD_MAJOR && mddev->ro && mddev->pers) {
                 if (mddev->ro == 2) {
                         mddev->ro = 0;
-                        sysfs_notify(&mddev->kobj, NULL, "array_state");
+                        sysfs_notify_dirent(mddev->sysfs_state);
                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
                         md_wakeup_thread(mddev->thread);
                 } else {
@@ -5612,7 +5617,7 @@ void md_write_start(mddev_t *mddev, struct bio *bi)
                 spin_unlock_irq(&mddev->write_lock);
         }
         if (did_change)
-                sysfs_notify(&mddev->kobj, NULL, "array_state");
+                sysfs_notify_dirent(mddev->sysfs_state);
         wait_event(mddev->sb_wait,
                    !test_bit(MD_CHANGE_CLEAN, &mddev->flags) &&
                    !test_bit(MD_CHANGE_PENDING, &mddev->flags));
@@ -5655,7 +5660,7 @@ int md_allow_write(mddev_t *mddev)
                         mddev->safemode = 1;
                 spin_unlock_irq(&mddev->write_lock);
                 md_update_sb(mddev, 0);
-                sysfs_notify(&mddev->kobj, NULL, "array_state");
+                sysfs_notify_dirent(mddev->sysfs_state);
         } else
                 spin_unlock_irq(&mddev->write_lock);
 
@@ -6048,9 +6053,6 @@ void md_check_recovery(mddev_t *mddev)
         if (mddev->bitmap)
                 bitmap_daemon_work(mddev->bitmap);
 
-        if (test_and_clear_bit(MD_NOTIFY_ARRAY_STATE, &mddev->flags))
-                sysfs_notify(&mddev->kobj, NULL, "array_state");
-
         if (mddev->ro)
                 return;
 
@@ -6103,7 +6105,7 @@ void md_check_recovery(mddev_t *mddev)
                                 mddev->safemode = 0;
                         spin_unlock_irq(&mddev->write_lock);
                         if (did_change)
-                                sysfs_notify(&mddev->kobj, NULL, "array_state");
+                                sysfs_notify_dirent(mddev->sysfs_state);
                 }
 
                 if (mddev->flags)
diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h
index c200b9a34aff..b16ad867e944 100644
--- a/include/linux/raid/md_k.h
+++ b/include/linux/raid/md_k.h
@@ -128,7 +128,6 @@ struct mddev_s
 #define MD_CHANGE_DEVS  0       /* Some device status has changed */
 #define MD_CHANGE_CLEAN 1       /* transition to or from 'clean' */
 #define MD_CHANGE_PENDING 2     /* superblock update in progress */
-#define MD_NOTIFY_ARRAY_STATE 3 /* atomic context wants to notify userspace */
 
         int                             ro;
 
@@ -239,6 +238,10 @@ struct mddev_s
         sector_t                        resync_max;     /* resync should pause
                                                          * when it gets here */
 
+        struct sysfs_dirent             *sysfs_state;   /* handle for 'array_state'
+                                                         * file in sysfs.
+                                                         */
+
         spinlock_t                      write_lock;
         wait_queue_head_t               sb_wait;        /* for waiting on superblock updates */
         atomic_t                        pending_writes; /* number of active superblock writes */