1 files changed, 44 insertions, 15 deletions

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index fcef3cae0c92..b8be6703189a 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -202,35 +202,64 @@ static noinline int wait_for_commit(struct btrfs_root *root,
         return 0;
 }
 
+void btrfs_throttle(struct btrfs_root *root)
+{
+        struct btrfs_fs_info *info = root->fs_info;
+
+harder:
+        if (atomic_read(&info->throttles)) {
+                DEFINE_WAIT(wait);
+                int thr;
+                int harder_count = 0;
+                thr = atomic_read(&info->throttle_gen);
+
+                do {
+                        prepare_to_wait(&info->transaction_throttle,
+                                        &wait, TASK_UNINTERRUPTIBLE);
+                        if (!atomic_read(&info->throttles)) {
+                                finish_wait(&info->transaction_throttle, &wait);
+                                break;
+                        }
+                        schedule();
+                        finish_wait(&info->transaction_throttle, &wait);
+                } while (thr == atomic_read(&info->throttle_gen));
+
+                if (harder_count < 5 &&
+                    info->total_ref_cache_size > 5 * 1024 * 1024) {
+                        harder_count++;
+                        goto harder;
+                }
+
+                if (harder_count < 10 &&
+                    info->total_ref_cache_size > 10 * 1024 * 1024) {
+                        harder_count++;
+                        goto harder;
+                }
+        }
+}
+
 static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
                           struct btrfs_root *root, int throttle)
 {
         struct btrfs_transaction *cur_trans;
+        struct btrfs_fs_info *info = root->fs_info;
 
-        mutex_lock(&root->fs_info->trans_mutex);
-        cur_trans = root->fs_info->running_transaction;
+        mutex_lock(&info->trans_mutex);
+        cur_trans = info->running_transaction;
         WARN_ON(cur_trans != trans->transaction);
         WARN_ON(cur_trans->num_writers < 1);
         cur_trans->num_writers--;
 
         if (waitqueue_active(&cur_trans->writer_wait))
                 wake_up(&cur_trans->writer_wait);
-
-        if (throttle && atomic_read(&root->fs_info->throttles)) {
-                DEFINE_WAIT(wait);
-                mutex_unlock(&root->fs_info->trans_mutex);
-                prepare_to_wait(&root->fs_info->transaction_throttle, &wait,
-                                TASK_UNINTERRUPTIBLE);
-                if (atomic_read(&root->fs_info->throttles))
-                        schedule();
-                finish_wait(&root->fs_info->transaction_throttle, &wait);
-                mutex_lock(&root->fs_info->trans_mutex);
-        }
-
         put_transaction(cur_trans);
-        mutex_unlock(&root->fs_info->trans_mutex);
+        mutex_unlock(&info->trans_mutex);
         memset(trans, 0, sizeof(*trans));
         kmem_cache_free(btrfs_trans_handle_cachep, trans);
+
+        if (throttle)
+                btrfs_throttle(root);
+
         return 0;
 }