Silence some compiler warnings.

[bluesky.git] / bluesky / cache.c

diff --git a/bluesky/cache.c b/bluesky/cache.c
index f953a64..912c5fd 100644 (file)
--- a/bluesky/cache.c
+++ b/bluesky/cache.c
@@ -13,8 +13,29 @@
 
 #include "bluesky-private.h"
 
+#define WRITEBACK_DELAY (5 * 1000000)
+
 /* Filesystem caching and cache coherency. */
 
+static void writeback_complete(gpointer a, gpointer i)
+{
+    BlueSkyInode *inode = (BlueSkyInode *)i;
+
+    g_log("bluesky/flushd", G_LOG_LEVEL_DEBUG,
+          "Writeback for inode %"PRIu64" complete", inode->inum);
+
+    g_mutex_lock(inode->lock);
+
+    inode->change_commit = inode->change_pending;
+    if (inode->change_count == inode->change_commit) {
+        /* If inode is no longer dirty... */
+        inode->change_time = 0;
+        inode->change_pending = 0;
+    }
+
+    g_mutex_unlock(inode->lock);
+}
+
 static void flushd_inode(gpointer key, gpointer value, gpointer user_data)
 {
     BlueSkyFS *fs = (BlueSkyFS *)user_data;
@@ -24,12 +45,34 @@ static void flushd_inode(gpointer key, gpointer value, gpointer user_data)
     if (inode->change_count == inode->change_commit)
         return;
 
+    if (inode->change_pending) {
+        /* Waiting for an earlier writeback to finish, so don't start a new
+         * writeback yet. */
+        return;
+    }
+
+    uint64_t elapsed = bluesky_get_current_time() - inode->change_time;
+    if (elapsed < WRITEBACK_DELAY) {
+        /* Give a bit more time before starting writeback. */
+        return;
+    }
+
+    inode->change_pending = inode->change_count;
+
     g_log("bluesky/flushd", G_LOG_LEVEL_DEBUG,
           "Starting flush of inode %"PRIu64, inode->inum);
 
-    if (inode->type == BLUESKY_REGULAR)
-        bluesky_file_flush(inode);
-    bluesky_inode_flush(fs, inode);
+    /* 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);
 }
 
 /* Scan through the cache for dirty data and start flushing it to stable