1 files changed, 38 insertions, 22 deletions

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index d04db817be5c..5011aadacab8 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -66,6 +66,8 @@
 static const struct super_operations btrfs_super_ops;
 static struct file_system_type btrfs_fs_type;
 
+static int btrfs_remount(struct super_block *sb, int *flags, char *data);
+
 static const char *btrfs_decode_error(int errno)
 {
 	char *errstr = "unknown";
@@ -1185,6 +1187,26 @@ static struct dentry *mount_subvol(const char *subvol_name, int flags,
 	mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
 			     newargs);
 	kfree(newargs);
+
+	if (PTR_RET(mnt) == -EBUSY) {
+		if (flags & MS_RDONLY) {
+			mnt = vfs_kern_mount(&btrfs_fs_type, flags & ~MS_RDONLY, device_name,
+					     newargs);
+		} else {
+			int r;
+			mnt = vfs_kern_mount(&btrfs_fs_type, flags | MS_RDONLY, device_name,
+					     newargs);
+			if (IS_ERR(mnt))
+				return ERR_CAST(mnt);
+
+			r = btrfs_remount(mnt->mnt_sb, &flags, NULL);
+			if (r < 0) {
+				/* FIXME: release vfsmount mnt ??*/
+				return ERR_PTR(r);
+			}
+		}
+	}
+
 	if (IS_ERR(mnt))
 		return ERR_CAST(mnt);
 
@@ -1305,13 +1327,6 @@ error_fs_info:
 	return ERR_PTR(error);
 }
 
-static void btrfs_set_max_workers(struct btrfs_workers *workers, int new_limit)
-{
-	spin_lock_irq(&workers->lock);
-	workers->max_workers = new_limit;
-	spin_unlock_irq(&workers->lock);
-}
-
 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
 				     int new_pool_size, int old_pool_size)
 {
@@ -1323,21 +1338,20 @@ static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
 	btrfs_info(fs_info, "resize thread pool %d -> %d",
 	       old_pool_size, new_pool_size);
 
-	btrfs_set_max_workers(&fs_info->generic_worker, new_pool_size);
-	btrfs_set_max_workers(&fs_info->workers, new_pool_size);
-	btrfs_set_max_workers(&fs_info->delalloc_workers, new_pool_size);
-	btrfs_set_max_workers(&fs_info->submit_workers, new_pool_size);
-	btrfs_set_max_workers(&fs_info->caching_workers, new_pool_size);
-	btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size);
-	btrfs_set_max_workers(&fs_info->endio_workers, new_pool_size);
-	btrfs_set_max_workers(&fs_info->endio_meta_workers, new_pool_size);
-	btrfs_set_max_workers(&fs_info->endio_meta_write_workers, new_pool_size);
-	btrfs_set_max_workers(&fs_info->endio_write_workers, new_pool_size);
-	btrfs_set_max_workers(&fs_info->endio_freespace_worker, new_pool_size);
-	btrfs_set_max_workers(&fs_info->delayed_workers, new_pool_size);
-	btrfs_set_max_workers(&fs_info->readahead_workers, new_pool_size);
-	btrfs_set_max_workers(&fs_info->scrub_wr_completion_workers,
-			      new_pool_size);
+	btrfs_workqueue_set_max(fs_info->workers, new_pool_size);
+	btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size);
+	btrfs_workqueue_set_max(fs_info->submit_workers, new_pool_size);
+	btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size);
+	btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size);
+	btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size);
+	btrfs_workqueue_set_max(fs_info->endio_meta_write_workers,
+				new_pool_size);
+	btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size);
+	btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size);
+	btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size);
+	btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size);
+	btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers,
+				new_pool_size);
 }
 
 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
@@ -1388,6 +1402,7 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
 	unsigned int old_metadata_ratio = fs_info->metadata_ratio;
 	int ret;
 
+	sync_filesystem(sb);
 	btrfs_remount_prepare(fs_info);
 
 	ret = btrfs_parse_options(root, data);
@@ -1479,6 +1494,7 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
 		sb->s_flags &= ~MS_RDONLY;
 	}
 out:
+	wake_up_process(fs_info->transaction_kthread);
 	btrfs_remount_cleanup(fs_info, old_opts);
 	return 0;