From: Michael Vrable <mvrable@cs.ucsd.edu>
Date: Thu, 29 Jul 2010 22:05:37 +0000 (-0700)
Subject: (Mostly) merge local and cloud logging together.
X-Git-Url: https://git.vrable.net/?a=commitdiff_plain;h=e9af23b41ae0c11245fbc6886a794e1dfb04a6bd;p=bluesky.git

(Mostly) merge local and cloud logging together.
---

diff --git a/bluesky/bluesky-private.h b/bluesky/bluesky-private.h
index 3cabcd1..a265796 100644
--- a/bluesky/bluesky-private.h
+++ b/bluesky/bluesky-private.h
@@ -139,43 +139,16 @@ void bluesky_store_sync(BlueSkyStore *store);
 void bluesky_store_add_barrier(BlueSkyStoreAsync *barrier,
                                BlueSkyStoreAsync *async);
 
-void bluesky_inode_start_sync(BlueSkyInode *inode, BlueSkyStoreAsync *barrier);
+void bluesky_inode_start_sync(BlueSkyInode *inode);
 
 void bluesky_block_touch(BlueSkyInode *inode, uint64_t i);
 void bluesky_block_fetch(BlueSkyFS *fs, BlueSkyBlock *block,
                          BlueSkyStoreAsync *barrier);
 void bluesky_block_flush(BlueSkyFS *fs, BlueSkyBlock *block,
-                         BlueSkyStoreAsync *barrier, GList **log_items);
-void bluesky_file_flush(BlueSkyInode *inode, BlueSkyStoreAsync *barrier,
-                        GList **log_items);
+                         GList **log_items);
+void bluesky_file_flush(BlueSkyInode *inode, GList **log_items);
 void bluesky_file_drop_cached(BlueSkyInode *inode);
 
-/* Logging infrastructure for ensuring operations are persistently recorded to
- * disk. */
-#define BLUESKY_CRC32C_SEED (~(uint32_t)0)
-uint32_t crc32c(uint32_t crc, const char *buf, unsigned int length);
-uint32_t crc32c_finalize(uint32_t crc);
-
-struct _BlueSkyLog {
-    char *log_directory;
-    GAsyncQueue *queue;
-    int fd;
-    int seq_num;
-};
-
-typedef struct {
-    gboolean committed;
-    GMutex *lock;
-    GCond *cond;
-    char *key;
-    BlueSkyRCStr *data;
-} BlueSkyLogItem;
-
-BlueSkyLog *bluesky_log_new(const char *log_directory);
-BlueSkyLogItem *bluesky_log_item_new();
-void bluesky_log_item_submit(BlueSkyLogItem *item, BlueSkyLog *log);
-void bluesky_log_item_finish(BlueSkyLogItem *item);
-
 /* Writing of data to the cloud in log segments and tracking the location of
  * various pieces of data (both where in the cloud and where cached locally).
  * */
@@ -207,6 +180,8 @@ typedef enum {
 #define CLOUDLOG_CLOUD      0x04
 typedef struct {
     gint refcount;
+    GMutex *lock;
+    GCond *cond;
 
     BlueSkyFS *fs;
 
@@ -214,6 +189,7 @@ typedef struct {
 
     // Bitmask of CLOUDLOG_* flags indicating where the object exists.
     int location_flags;
+    int pending_read, pending_write;
 
     // A stable identifier for the object (only changes when authenticated data
     // is written out, but stays the same when the in-cloud cleaner relocates
@@ -228,6 +204,7 @@ typedef struct {
     BlueSkyCloudPointer location;
 
     // TODO: Location in journal/cache
+    int log_seq, log_offset, log_size;
 
     // Pointers to other objects
     GArray *pointers;
@@ -250,10 +227,27 @@ gchar *bluesky_cloudlog_id_to_string(BlueSkyCloudID id);
 BlueSkyCloudID bluesky_cloudlog_id_from_string(const gchar *idstr);
 void bluesky_cloudlog_ref(BlueSkyCloudLog *log);
 void bluesky_cloudlog_unref(BlueSkyCloudLog *log);
-BlueSkyLogItem *bluesky_cloudlog_sync(BlueSkyCloudLog *log);
+void bluesky_cloudlog_sync(BlueSkyCloudLog *log);
 void bluesky_cloudlog_insert(BlueSkyCloudLog *log);
 void bluesky_cloudlog_write_log(BlueSkyFS *fs);
 
+/* Logging infrastructure for ensuring operations are persistently recorded to
+ * disk. */
+#define BLUESKY_CRC32C_SEED (~(uint32_t)0)
+uint32_t crc32c(uint32_t crc, const char *buf, unsigned int length);
+uint32_t crc32c_finalize(uint32_t crc);
+
+struct _BlueSkyLog {
+    char *log_directory;
+    GAsyncQueue *queue;
+    int fd;
+    int seq_num;
+};
+
+BlueSkyLog *bluesky_log_new(const char *log_directory);
+void bluesky_log_item_submit(BlueSkyCloudLog *item, BlueSkyLog *log);
+void bluesky_log_finish_all(GList *log_items);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/bluesky/cache.c b/bluesky/cache.c
index 441e6c4..587f98b 100644
--- a/bluesky/cache.c
+++ b/bluesky/cache.c
@@ -78,17 +78,7 @@ static void flushd_dirty_inode(BlueSkyInode *inode)
     }
     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);
+    bluesky_inode_start_sync(inode);
 }
 
 /* Try to flush dirty data to disk, either due to memory pressure or due to
diff --git a/bluesky/cloudlog.c b/bluesky/cloudlog.c
index e1fd44a..82f0f65 100644
--- a/bluesky/cloudlog.c
+++ b/bluesky/cloudlog.c
@@ -86,6 +86,8 @@ BlueSkyCloudLog *bluesky_cloudlog_new(BlueSkyFS *fs)
 {
     BlueSkyCloudLog *log = g_new0(BlueSkyCloudLog, 1);
 
+    log->lock = g_mutex_new();
+    log->cond = g_cond_new();
     log->fs = fs;
     log->type = LOGTYPE_UNKNOWN;
     log->id = bluesky_cloudlog_new_id();
@@ -108,14 +110,9 @@ void bluesky_cloudlog_unref(BlueSkyCloudLog *log)
 }
 
 /* Start a write of the object to the local log. */
-BlueSkyLogItem *bluesky_cloudlog_sync(BlueSkyCloudLog *log)
+void bluesky_cloudlog_sync(BlueSkyCloudLog *log)
 {
-    BlueSkyLogItem *log_item = bluesky_log_item_new();
-    log_item->key = bluesky_cloudlog_id_to_string(log->id);
-    log_item->data = log->data;
-    bluesky_string_ref(log->data);
-    bluesky_log_item_submit(log_item, log->fs->log);
-    return log_item;
+    bluesky_log_item_submit(log, log->fs->log);
 }
 
 /* Add the given entry to the global hash table containing cloud log entries.
diff --git a/bluesky/debug.c b/bluesky/debug.c
index ca09868..8d4d8d2 100644
--- a/bluesky/debug.c
+++ b/bluesky/debug.c
@@ -42,8 +42,9 @@ static void cloudlog_dump(gpointer key, gpointer value, gpointer user_data)
     for (int i = 0; i < sizeof(BlueSkyCloudID); i++) {
         g_print("%02x", (uint8_t)(log->id.bytes[i]));
     }
-    g_print(": ty=%d inode=%"PRIu64" locs=%x\n",
-            log->type, log->inum, log->location_flags);
+    g_print(": ty=%d inode=%"PRIu64" locs=%x log@(%d,%d)\n",
+            log->type, log->inum, log->location_flags,
+            log->log_seq, log->log_offset);
 }
 
 /* Dump a summary of filesystem state as it is cached in memory. */
diff --git a/bluesky/file.c b/bluesky/file.c
index 8faae00..2e4313e 100644
--- a/bluesky/file.c
+++ b/bluesky/file.c
@@ -258,7 +258,6 @@ void bluesky_block_fetch(BlueSkyFS *fs, BlueSkyBlock *block,
 
 /* Write the given block to cloud-backed storage and mark it clean. */
 void bluesky_block_flush(BlueSkyFS *fs, BlueSkyBlock *block,
-                         BlueSkyStoreAsync *barrier,
                          GList **log_items)
 {
     if (block->type != BLUESKY_BLOCK_DIRTY)
@@ -272,21 +271,10 @@ void bluesky_block_flush(BlueSkyFS *fs, BlueSkyBlock *block,
     cloudlog->inum = 0; //FIXME
     cloudlog->data = data;
     bluesky_string_ref(data);
-    *log_items = g_list_prepend(*log_items, bluesky_cloudlog_sync(cloudlog));
+    bluesky_cloudlog_sync(cloudlog);
+    *log_items = g_list_prepend(*log_items, cloudlog);
     bluesky_cloudlog_insert(cloudlog);
 
-    /* Store the file data asynchronously, and don't bother waiting for a
-     * response. */
-    BlueSkyStoreAsync *async = bluesky_store_async_new(fs->store);
-    async->op = STORE_OP_PUT;
-    async->key = g_strdup(name);
-    bluesky_string_ref(data);
-    async->data = data;
-    bluesky_store_async_submit(async);
-    if (barrier != NULL)
-        bluesky_store_add_barrier(barrier, async);
-    bluesky_store_async_unref(async);
-
     g_free(block->ref);
     block->ref = name;
 
@@ -295,14 +283,13 @@ void bluesky_block_flush(BlueSkyFS *fs, BlueSkyBlock *block,
 }
 
 /* Flush all blocks in a file to stable storage. */
-void bluesky_file_flush(BlueSkyInode *inode, BlueSkyStoreAsync *barrier,
-                        GList **log_items)
+void bluesky_file_flush(BlueSkyInode *inode, GList **log_items)
 {
     g_return_if_fail(inode->type == BLUESKY_REGULAR);
 
     for (int i = 0; i < inode->blocks->len; i++) {
         BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock, i);
-        bluesky_block_flush(inode->fs, b, barrier, log_items);
+        bluesky_block_flush(inode->fs, b, log_items);
     }
 }
 
diff --git a/bluesky/inode.c b/bluesky/inode.c
index 745d81b..0844f79 100644
--- a/bluesky/inode.c
+++ b/bluesky/inode.c
@@ -307,13 +307,13 @@ void bluesky_inode_flush(BlueSkyFS *fs, BlueSkyInode *inode)
 }
 
 /* Start writeback of an inode and all associated data. */
-void bluesky_inode_start_sync(BlueSkyInode *inode, BlueSkyStoreAsync *barrier)
+void bluesky_inode_start_sync(BlueSkyInode *inode)
 {
     GList *log_items = NULL;
     BlueSkyFS *fs = inode->fs;
 
     if (inode->type == BLUESKY_REGULAR)
-        bluesky_file_flush(inode, barrier, &log_items);
+        bluesky_file_flush(inode, &log_items);
 
     GString *buf = g_string_new("");
     bluesky_serialize_inode(buf, inode);
@@ -340,42 +340,23 @@ void bluesky_inode_start_sync(BlueSkyInode *inode, BlueSkyStoreAsync *barrier)
         }
     }
 
-    log_items = g_list_prepend(log_items, bluesky_cloudlog_sync(cloudlog));
-
+    bluesky_cloudlog_sync(cloudlog);
+    log_items = g_list_prepend(log_items, cloudlog);
     bluesky_cloudlog_insert(cloudlog);
 
     /* Wait for all log items to be committed to disk. */
-    while (log_items != NULL) {
-        BlueSkyLogItem *log_item = (BlueSkyLogItem *)log_items->data;
-        bluesky_log_item_finish(log_item);
-        log_items = g_list_delete_link(log_items, log_items);
-    }
-
-    BlueSkyStoreAsync *async = bluesky_store_async_new(fs->store);
-    async->op = STORE_OP_PUT;
-    async->key = g_strdup(key);
-    async->data = data;
-    bluesky_store_async_submit(async);
-    if (barrier != NULL)
-        bluesky_store_add_barrier(barrier, async);
-    bluesky_store_async_unref(async);
+    bluesky_log_finish_all(log_items);
 }
 
 /* Write back an inode and all associated data and wait for completion.  Inode
  * should already be locked. */
 void bluesky_inode_do_sync(BlueSkyInode *inode)
 {
-    BlueSkyStoreAsync *barrier = bluesky_store_async_new(inode->fs->store);
-    barrier->op = STORE_OP_BARRIER;
-
     if (bluesky_verbose) {
         g_log("bluesky/inode", G_LOG_LEVEL_DEBUG,
             "Synchronous writeback for inode %"PRIu64"...", inode->inum);
     }
-    bluesky_inode_start_sync(inode, barrier);
-    bluesky_store_async_submit(barrier);
-    bluesky_store_async_wait(barrier);
-    bluesky_store_async_unref(barrier);
+    bluesky_inode_start_sync(inode);
     if (bluesky_verbose) {
         g_log("bluesky/inode", G_LOG_LEVEL_DEBUG,
               "Writeback for inode %"PRIu64" complete", inode->inum);
diff --git a/bluesky/log.c b/bluesky/log.c
index 4c522b8..e9af52a 100644
--- a/bluesky/log.c
+++ b/bluesky/log.c
@@ -43,8 +43,8 @@
 struct log_header {
     uint32_t magic;             // HEADER_MAGIC
     uint64_t offset;            // Starting byte offset of the log header
-    uint32_t keysize;           // Size of the log key (bytes)
     uint32_t size;              // Size of the data item (bytes)
+    BlueSkyCloudID id;          // Object identifier
 } __attribute__((packed));
 
 struct log_footer {
@@ -110,8 +110,18 @@ static gpointer log_thread(gpointer d)
             fsync(dirfd);
         }
 
-        BlueSkyLogItem *item = (BlueSkyLogItem *)g_async_queue_pop(log->queue);
+        BlueSkyCloudLog *item
+            = (BlueSkyCloudLog *)g_async_queue_pop(log->queue);
         g_mutex_lock(item->lock);
+        g_assert(item->data != NULL);
+
+        if ((item->location_flags | item->pending_write) & CLOUDLOG_JOURNAL) {
+            g_mutex_unlock(item->lock);
+            bluesky_cloudlog_unref(item);
+            continue;
+        }
+
+        item->pending_write |= CLOUDLOG_JOURNAL;
 
         off_t logsize = lseek(log->fd, 0, SEEK_CUR);
         struct log_header header;
@@ -119,8 +129,8 @@ static gpointer log_thread(gpointer d)
 
         header.magic = GUINT32_TO_LE(HEADER_MAGIC);
         header.offset = GUINT64_TO_LE(logsize);
-        header.keysize = GUINT32_TO_LE(strlen(item->key));
         header.size = GUINT32_TO_LE(item->data->len);
+        header.id = item->id;
         footer.magic = GUINT32_TO_LE(FOOTER_MAGIC);
 
         uint32_t crc = BLUESKY_CRC32C_SEED;
@@ -128,9 +138,6 @@ static gpointer log_thread(gpointer d)
         writebuf(log->fd, (const char *)&header, sizeof(header));
         crc = crc32c(crc, (const char *)&header, sizeof(header));
 
-        writebuf(log->fd, item->key, strlen(item->key));
-        crc = crc32c(crc, item->key, strlen(item->key));
-
         writebuf(log->fd, item->data->data, item->data->len);
         crc = crc32c(crc, item->data->data, item->data->len);
 
@@ -139,10 +146,14 @@ static gpointer log_thread(gpointer d)
         footer.crc = crc32c_finalize(crc);
         writebuf(log->fd, (const char *)&footer, sizeof(footer));
 
-        logsize += sizeof(header) + sizeof(footer);
-        logsize += strlen(item->key) + item->data->len;
+        item->log_seq = log->seq_num;
+        item->log_offset = logsize + sizeof(header);
+        item->log_size = item->data->len;
+
+        logsize += sizeof(header) + sizeof(footer) + item->data->len;
 
         committed  = g_slist_prepend(committed, item);
+        g_mutex_unlock(item->lock);
 
         /* Force an fsync either if we will be closing this log segment and
          * opening a new file, or if there are no other log items currently
@@ -154,8 +165,10 @@ static gpointer log_thread(gpointer d)
             int batchsize = 0;
             fdatasync(log->fd);
             while (committed != NULL) {
-                item = (BlueSkyLogItem *)committed->data;
-                item->committed = TRUE;
+                item = (BlueSkyCloudLog *)committed->data;
+                g_mutex_lock(item->lock);
+                item->pending_write &= ~CLOUDLOG_JOURNAL;
+                item->location_flags |= CLOUDLOG_JOURNAL;
                 g_cond_signal(item->cond);
                 g_mutex_unlock(item->lock);
                 committed = g_slist_delete_link(committed, committed);
@@ -189,36 +202,23 @@ BlueSkyLog *bluesky_log_new(const char *log_directory)
     return log;
 }
 
-BlueSkyLogItem *bluesky_log_item_new()
-{
-    BlueSkyLogItem *item = g_new(BlueSkyLogItem, 1);
-    item->committed = FALSE;
-    item->lock = g_mutex_new();
-    item->cond = g_cond_new();
-    item->key = NULL;
-    item->data = NULL;
-    return item;
-}
-
-void bluesky_log_item_submit(BlueSkyLogItem *item, BlueSkyLog *log)
+void bluesky_log_item_submit(BlueSkyCloudLog *item, BlueSkyLog *log)
 {
+    bluesky_cloudlog_ref(item);
     g_async_queue_push(log->queue, item);
 }
 
-static void bluesky_log_item_free(BlueSkyLogItem *item)
+void bluesky_log_finish_all(GList *log_items)
 {
-    g_free(item->key);
-    bluesky_string_unref(item->data);
-    g_mutex_free(item->lock);
-    g_cond_free(item->cond);
-    g_free(item);
-}
+    while (log_items != NULL) {
+        BlueSkyCloudLog *item = (BlueSkyCloudLog *)log_items->data;
 
-void bluesky_log_item_finish(BlueSkyLogItem *item)
-{
-    g_mutex_lock(item->lock);
-    while (!item->committed)
-        g_cond_wait(item->cond, item->lock);
-    g_mutex_unlock(item->lock);
-    bluesky_log_item_free(item);
+        g_mutex_lock(item->lock);
+        while ((item->pending_write & CLOUDLOG_JOURNAL))
+            g_cond_wait(item->cond, item->lock);
+        g_mutex_unlock(item->lock);
+        bluesky_cloudlog_unref(item);
+
+        log_items = g_list_delete_link(log_items, log_items);
+    }
 }