Btrfs: Catch missed bios in the async bio submission thread

The async bio submission thread was missing some bios that were
added after it had decided there was no work left to do.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c
index d5f4e94f2ca238b2afe5ea925363dda47ca5b585..f2e80f3768ec76266d3c4424946d7e4e000da427 100644 (file)
--- a/fs/btrfs/async-thread.c
+++ b/fs/btrfs/async-thread.c
@@ -349,6 +349,7 @@ int btrfs_requeue_work(struct btrfs_work *work)
 {
        struct btrfs_worker_thread *worker = work->worker;
        unsigned long flags;
+       int wake = 0;
 
        if (test_and_set_bit(WORK_QUEUED_BIT, &work->flags))
                goto out;
@@ -367,10 +368,16 @@ int btrfs_requeue_work(struct btrfs_work *work)
                               &worker->workers->worker_list);
                spin_unlock_irqrestore(&worker->workers->lock, flags);
        }
+       if (!worker->working) {
+               wake = 1;
+               worker->working = 1;
+       }
 
        spin_unlock_irqrestore(&worker->lock, flags);
-
+       if (wake)
+               wake_up_process(worker->task);
 out:
+
        return 0;
 }
 
@@ -397,6 +404,7 @@ int btrfs_queue_worker(struct btrfs_workers *workers, struct btrfs_work *work)
        }
 
        spin_lock_irqsave(&worker->lock, flags);
+
        atomic_inc(&worker->num_pending);
        check_busy_worker(worker);
        list_add_tail(&work->list, &worker->pending);

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index fd0bedb07a6405d78f66ef7de63965b17d5617d3..bcd14ebccae16e751e67a73cf79c2dfbbf0db465 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -154,6 +154,7 @@ static noinline int run_scheduled_bios(struct btrfs_device *device)
 loop:
        spin_lock(&device->io_lock);
 
+loop_lock:
        /* take all the bios off the list at once and process them
         * later on (without the lock held).  But, remember the
         * tail and other pointers so the bios can be properly reinserted
@@ -203,7 +204,7 @@ loop:
                 * is now congested.  Back off and let other work structs
                 * run instead
                 */
-               if (pending && bdi_write_congested(bdi) &&
+               if (pending && bdi_write_congested(bdi) && num_run > 16 &&
                    fs_info->fs_devices->open_devices > 1) {
                        struct bio *old_head;
 
@@ -215,7 +216,8 @@ loop:
                                tail->bi_next = old_head;
                        else
                                device->pending_bio_tail = tail;
-                       device->running_pending = 0;
+
+                       device->running_pending = 1;
 
                        spin_unlock(&device->io_lock);
                        btrfs_requeue_work(&device->work);
@@ -224,6 +226,11 @@ loop:
        }
        if (again)
                goto loop;
+
+       spin_lock(&device->io_lock);
+       if (device->pending_bios)
+               goto loop_lock;
+       spin_unlock(&device->io_lock);
 done:
        return 0;
 }