Merge branch 'for-linus-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason...

[linux-drm-fsl-dcu.git] / fs / btrfs / disk-io.c

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index b59deb2c63f4e2fe6cfb83cbbada6e4a45f8f002..a9aadb2ad5254cfe98d36a6eed1f12d4ae5e7925 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1744,13 +1744,14 @@ static void end_workqueue_fn(struct btrfs_work *work)
        bio->bi_private = end_io_wq->private;
        bio->bi_end_io = end_io_wq->end_io;
        kmem_cache_free(btrfs_end_io_wq_cache, end_io_wq);
-       bio_endio_nodec(bio, error);
+       bio_endio(bio, error);
 }
 
 static int cleaner_kthread(void *arg)
 {
        struct btrfs_root *root = arg;
        int again;
+       struct btrfs_trans_handle *trans;
 
        do {
                again = 0;
@@ -1798,6 +1799,34 @@ sleep:
                        __set_current_state(TASK_RUNNING);
                }
        } while (!kthread_should_stop());
+
+       /*
+        * Transaction kthread is stopped before us and wakes us up.
+        * However we might have started a new transaction and COWed some
+        * tree blocks when deleting unused block groups for example. So
+        * make sure we commit the transaction we started to have a clean
+        * shutdown when evicting the btree inode - if it has dirty pages
+        * when we do the final iput() on it, eviction will trigger a
+        * writeback for it which will fail with null pointer dereferences
+        * since work queues and other resources were already released and
+        * destroyed by the time the iput/eviction/writeback is made.
+        */
+       trans = btrfs_attach_transaction(root);
+       if (IS_ERR(trans)) {
+               if (PTR_ERR(trans) != -ENOENT)
+                       btrfs_err(root->fs_info,
+                                 "cleaner transaction attach returned %ld",
+                                 PTR_ERR(trans));
+       } else {
+               int ret;
+
+               ret = btrfs_commit_transaction(trans, root);
+               if (ret)
+                       btrfs_err(root->fs_info,
+                                 "cleaner open transaction commit returned %d",
+                                 ret);
+       }
+
        return 0;
 }
 
@@ -3296,11 +3325,8 @@ static int write_dev_supers(struct btrfs_device *device,
  */
 static void btrfs_end_empty_barrier(struct bio *bio, int err)
 {
-       if (err) {
-               if (err == -EOPNOTSUPP)
-                       set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
+       if (err)
                clear_bit(BIO_UPTODATE, &bio->bi_flags);
-       }
        if (bio->bi_private)
                complete(bio->bi_private);
        bio_put(bio);
@@ -3328,11 +3354,7 @@ static int write_dev_flush(struct btrfs_device *device, int wait)
 
                wait_for_completion(&device->flush_wait);
 
-               if (bio_flagged(bio, BIO_EOPNOTSUPP)) {
-                       printk_in_rcu("BTRFS: disabling barriers on dev %s\n",
-                                     rcu_str_deref(device->name));
-                       device->nobarriers = 1;
-               } else if (!bio_flagged(bio, BIO_UPTODATE)) {
+               if (!bio_flagged(bio, BIO_UPTODATE)) {
                        ret = -EIO;
                        btrfs_dev_stat_inc_and_print(device,
                                BTRFS_DEV_STAT_FLUSH_ERRS);