From: Michael Vrable <mvrable@cs.ucsd.edu>
Date: Thu, 28 Jan 2010 19:50:07 +0000 (-0800)
Subject: Finish up asynchronous inode loading.
X-Git-Url: https://git.vrable.net/?a=commitdiff_plain;h=19a4f95aded09eed08b3a48ebe23f48eb74a93bf;p=bluesky.git

Finish up asynchronous inode loading.
---

diff --git a/bluesky/inode.c b/bluesky/inode.c
index a568ae0..cfa6697 100644
--- a/bluesky/inode.c
+++ b/bluesky/inode.c
@@ -269,27 +269,49 @@ void bluesky_inode_do_sync(BlueSkyInode *inode)
           "Writeback for inode %"PRIu64" complete", inode->inum);
 }
 
-/* Fetch an inode from stable storage. */
+static void complete_inode_fetch(BlueSkyStoreAsync *async, BlueSkyInode *inode)
+{
+    g_print("Completing fetch of inode %"PRIu64"...\n", inode->inum);
+
+    if (async->result != 0
+        || !bluesky_deserialize_inode(inode, async->data->data))
+    {
+        g_print("    failed to load inode, cleaning up\n");
+        g_mutex_lock(inode->fs->lock);
+        g_hash_table_remove(inode->fs->inodes, &inode->inum);
+        g_mutex_unlock(inode->fs->lock);
+        bluesky_inode_unref(inode);
+    }
+
+    g_mutex_unlock(inode->lock);
+    bluesky_inode_unref(inode);
+}
+
+/* Fetch an inode from stable storage.  The fetch can be performed
+ * asynchronously: the in-memory inode is allocated, but not filled with data
+ * immediately.  It is kept locked until it has been filled in, so any users
+ * should try to acquire the lock on the inode before accessing any data.  The
+ * fs lock must be held. */
 void bluesky_inode_fetch(BlueSkyFS *fs, uint64_t inum)
 {
     char key[64];
     sprintf(key, "inode-%016"PRIx64, inum);
-    BlueSkyRCStr *data = bluesky_store_get(fs->store, key);
-    if (data == NULL)
-        return;
 
     BlueSkyInode *inode = bluesky_new_inode(inum, fs, BLUESKY_PENDING);
-    bluesky_inode_ref(inode);
+    bluesky_inode_ref(inode);       // Extra ref held by fetching process
     g_mutex_lock(inode->lock);
     bluesky_insert_inode(fs, inode);
 
-    if (!bluesky_deserialize_inode(inode, data->data)) {
-        g_hash_table_remove(fs->inodes, &inode->inum);
-        bluesky_inode_unref(inode);
-    }
+    BlueSkyStoreAsync *async = bluesky_store_async_new(fs->store);
+    async->op = STORE_OP_GET;
+    async->key = g_strdup(key);
 
-    g_mutex_unlock(inode->lock);
-    bluesky_inode_unref(inode);
+    bluesky_store_async_add_notifier(async, (GFunc)complete_inode_fetch, inode);
+    bluesky_store_async_submit(async);
+
+    if (bluesky_options.sync_inode_fetches) {
+        bluesky_store_async_wait(async);
+    }
 }
 
 /* Synchronize filesystem superblock to stable storage. */