md: rename mddev->write_lock to mddev->lock

This lock is used for (slightly) more than helping with writing
superblocks, and it will soon be extended further.  So the
name is inappropriate.

Also, the _irq variant hasn't been needed since 2.6.37 as it is
never taking from interrupt or bh context.

So:
  -rename write_lock to lock
  -document what it protects
  -remove _irq ... except in md_flush_request() as there
     is no wait_event_lock() (with no _irq).  This can be
     cleaned up after appropriate changes to wait.h.

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

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 709755f..17e7fd7 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -397,12 +397,12 @@ static void md_submit_flush_data(struct work_struct *ws)
 
 void md_flush_request(struct mddev *mddev, struct bio *bio)
 {
-       spin_lock_irq(&mddev->write_lock);
+       spin_lock_irq(&mddev->lock);
        wait_event_lock_irq(mddev->sb_wait,
                            !mddev->flush_bio,
-                           mddev->write_lock);
+                           mddev->lock);
        mddev->flush_bio = bio;
-       spin_unlock_irq(&mddev->write_lock);
+       spin_unlock_irq(&mddev->lock);
 
        INIT_WORK(&mddev->flush_work, submit_flushes);
        queue_work(md_wq, &mddev->flush_work);
@@ -465,7 +465,7 @@ void mddev_init(struct mddev *mddev)
        atomic_set(&mddev->active, 1);
        atomic_set(&mddev->openers, 0);
        atomic_set(&mddev->active_io, 0);
-       spin_lock_init(&mddev->write_lock);
+       spin_lock_init(&mddev->lock);
        atomic_set(&mddev->flush_pending, 0);
        init_waitqueue_head(&mddev->sb_wait);
        init_waitqueue_head(&mddev->recovery_wait);
@@ -2230,7 +2230,7 @@ repeat:
                return;
        }
 
-       spin_lock_irq(&mddev->write_lock);
+       spin_lock(&mddev->lock);
 
        mddev->utime = get_seconds();
 
@@ -2287,7 +2287,7 @@ repeat:
        }
 
        sync_sbs(mddev, nospares);
-       spin_unlock_irq(&mddev->write_lock);
+       spin_unlock(&mddev->lock);
 
        pr_debug("md: updating %s RAID superblock on device (in sync %d)\n",
                 mdname(mddev), mddev->in_sync);
@@ -2326,15 +2326,15 @@ repeat:
        md_super_wait(mddev);
        /* if there was a failure, MD_CHANGE_DEVS was set, and we re-write super */
 
-       spin_lock_irq(&mddev->write_lock);
+       spin_lock(&mddev->lock);
        if (mddev->in_sync != sync_req ||
            test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
                /* have to write it out again */
-               spin_unlock_irq(&mddev->write_lock);
+               spin_unlock(&mddev->lock);
                goto repeat;
        }
        clear_bit(MD_CHANGE_PENDING, &mddev->flags);
-       spin_unlock_irq(&mddev->write_lock);
+       spin_unlock(&mddev->lock);
        wake_up(&mddev->sb_wait);
        if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
                sysfs_notify(&mddev->kobj, NULL, "sync_completed");
@@ -3722,7 +3722,7 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len)
        case clean:
                if (mddev->pers) {
                        restart_array(mddev);
-                       spin_lock_irq(&mddev->write_lock);
+                       spin_lock(&mddev->lock);
                        if (atomic_read(&mddev->writes_pending) == 0) {
                                if (mddev->in_sync == 0) {
                                        mddev->in_sync = 1;
@@ -3733,7 +3733,7 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len)
                                err = 0;
                        } else
                                err = -EBUSY;
-                       spin_unlock_irq(&mddev->write_lock);
+                       spin_unlock(&mddev->lock);
                } else
                        err = -EINVAL;
                break;
@@ -7102,7 +7102,7 @@ void md_write_start(struct mddev *mddev, struct bio *bi)
        if (mddev->safemode == 1)
                mddev->safemode = 0;
        if (mddev->in_sync) {
-               spin_lock_irq(&mddev->write_lock);
+               spin_lock(&mddev->lock);
                if (mddev->in_sync) {
                        mddev->in_sync = 0;
                        set_bit(MD_CHANGE_CLEAN, &mddev->flags);
@@ -7110,7 +7110,7 @@ void md_write_start(struct mddev *mddev, struct bio *bi)
                        md_wakeup_thread(mddev->thread);
                        did_change = 1;
                }
-               spin_unlock_irq(&mddev->write_lock);
+               spin_unlock(&mddev->lock);
        }
        if (did_change)
                sysfs_notify_dirent_safe(mddev->sysfs_state);
@@ -7148,7 +7148,7 @@ int md_allow_write(struct mddev *mddev)
        if (!mddev->pers->sync_request)
                return 0;
 
-       spin_lock_irq(&mddev->write_lock);
+       spin_lock(&mddev->lock);
        if (mddev->in_sync) {
                mddev->in_sync = 0;
                set_bit(MD_CHANGE_CLEAN, &mddev->flags);
@@ -7156,11 +7156,11 @@ int md_allow_write(struct mddev *mddev)
                if (mddev->safemode_delay &&
                    mddev->safemode == 0)
                        mddev->safemode = 1;
-               spin_unlock_irq(&mddev->write_lock);
+               spin_unlock(&mddev->lock);
                md_update_sb(mddev, 0);
                sysfs_notify_dirent_safe(mddev->sysfs_state);
        } else
-               spin_unlock_irq(&mddev->write_lock);
+               spin_unlock(&mddev->lock);
 
        if (test_bit(MD_CHANGE_PENDING, &mddev->flags))
                return -EAGAIN;
@@ -7688,7 +7688,7 @@ void md_check_recovery(struct mddev *mddev)
 
                if (!mddev->external) {
                        int did_change = 0;
-                       spin_lock_irq(&mddev->write_lock);
+                       spin_lock(&mddev->lock);
                        if (mddev->safemode &&
                            !atomic_read(&mddev->writes_pending) &&
                            !mddev->in_sync &&
@@ -7699,7 +7699,7 @@ void md_check_recovery(struct mddev *mddev)
                        }
                        if (mddev->safemode == 1)
                                mddev->safemode = 0;
-                       spin_unlock_irq(&mddev->write_lock);
+                       spin_unlock(&mddev->lock);
                        if (did_change)
                                sysfs_notify_dirent_safe(mddev->sysfs_state);
                }

diff --git a/drivers/md/md.h b/drivers/md/md.h
index 03cec5b..f0d15bd 100644 (file)
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -386,7 +386,13 @@ struct mddev {
 
        struct work_struct del_work;    /* used for delayed sysfs removal */
 
-       spinlock_t                      write_lock;
+       /* "lock" protects:
+        *   flush_bio transition from NULL to !NULL
+        *   rdev superblocks, events
+        *   clearing MD_CHANGE_*
+        *   in_sync - and related safemode and MD_CHANGE changes
+        */
+       spinlock_t                      lock;
        wait_queue_head_t               sb_wait;        /* for waiting on superblock updates */
        atomic_t                        pending_writes; /* number of active superblock writes */