+ BlueSkyFS *fs = inode->fs;
+
+ g_mutex_lock(fs->lock);
+ bluesky_list_unlink(&fs->dirty_list, inode->dirty_list);
+ inode->dirty_list = NULL;
+ g_mutex_unlock(fs->lock);
+
+ /* Inode is clean; nothing to do. */
+ if (inode->change_count == inode->change_commit)
+ return;
+
+ /* Inode writeback is in progress; put back on the dirty list. */
+ if (inode->change_pending) {
+ /* Waiting for an earlier writeback to finish, so don't start a new
+ * writeback yet. */
+ g_mutex_lock(fs->lock);
+ inode->change_time = bluesky_get_current_time();
+ bluesky_list_unlink(&fs->dirty_list, inode->dirty_list);
+ inode->dirty_list = bluesky_list_prepend(&fs->dirty_list, inode);
+ g_mutex_unlock(fs->lock);
+ return;
+ }
+
+ if (bluesky_verbose) {
+ g_log("bluesky/flushd", G_LOG_LEVEL_DEBUG,
+ "Starting flush of inode %"PRIu64, inode->inum);
+ }
+ inode->change_pending = inode->change_count;
+
+ /* Create a store barrier. All operations part of the writeback will be
+ * added to this barrier, so when the barrier completes we know that the
+ * writeback is finished. */
+ BlueSkyStoreAsync *barrier = bluesky_store_async_new(fs->store);
+ barrier->op = STORE_OP_BARRIER;
+
+ bluesky_inode_start_sync(inode, barrier);
+
+ bluesky_store_async_add_notifier(barrier, writeback_complete, inode);
+ bluesky_store_async_submit(barrier);
+ bluesky_store_async_unref(barrier);
+}
+
+/* Try to flush dirty data to disk, either due to memory pressure or due to
+ * timeouts. */
+static void flushd_dirty(BlueSkyFS *fs)
+{
+ int64_t start_time = bluesky_get_current_time();
+ g_mutex_lock(fs->lock);
+
+ while (1) {
+ BlueSkyInode *inode;
+ if (fs->dirty_list.prev == NULL)
+ break;
+ inode = fs->dirty_list.prev->data;