* persistent storage. */
void bluesky_serialize_superblock(GString *out, BlueSkyFS *fs);
BlueSkyFS *bluesky_deserialize_superblock(const gchar *buf);
-void bluesky_serialize_inode(GString *out, BlueSkyInode *inode);
+BlueSkyCloudLog *bluesky_serialize_inode(BlueSkyInode *inode);
gboolean bluesky_deserialize_inode(BlueSkyInode *inode, const gchar *buf);
/* Storage layer. Requests can be performed asynchronously, so these objects
void bluesky_inode_start_sync(BlueSkyInode *inode);
void bluesky_block_touch(BlueSkyInode *inode, uint64_t i);
-void bluesky_block_fetch(BlueSkyFS *fs, BlueSkyBlock *block,
+void bluesky_block_fetch(BlueSkyInode *inode, BlueSkyBlock *block,
BlueSkyStoreAsync *barrier);
-void bluesky_block_flush(BlueSkyFS *fs, BlueSkyBlock *block,
+void bluesky_block_flush(BlueSkyInode *inode, BlueSkyBlock *block,
GList **log_items);
void bluesky_file_flush(BlueSkyInode *inode, GList **log_items);
void bluesky_file_drop_cached(BlueSkyInode *inode);
} BlueSkyCloudPointer;
typedef enum {
+ LOGTYPE_INVALID = -1,
LOGTYPE_UNKNOWN = 0,
LOGTYPE_DATA = 1,
LOGTYPE_INODE = 2,
/* A record which tracks an object which has been written to a local log,
* cached, locally, and/or written to the cloud. */
#define CLOUDLOG_JOURNAL 0x01
-#define CLOUDLOG_CACHE 0x02
-#define CLOUDLOG_CLOUD 0x04
-typedef struct {
+#define CLOUDLOG_CLOUD 0x02
+#define CLOUDLOG_CACHE 0x04
+struct _BlueSkyCloudLog {
gint refcount;
GMutex *lock;
GCond *cond;
int location_flags;
int pending_read, pending_write;
+ // If the object is not yet flushed to cloud storage but is written to a
+ // journal file locally, a reference to that journal file so that we can
+ // keep the dirty_refs count updated. When the object is deleted or
+ // becomes clean, decrement the dirty_refs counter of the journal file and
+ // set this pointer to NULL.
+ BlueSkyCacheFile *dirty_journal;
+
// A stable identifier for the object (only changes when authenticated data
// is written out, but stays the same when the in-cloud cleaner relocates
// the object).
// TODO: Location in journal/cache
int log_seq, log_offset, log_size;
- // Pointers to other objects
- GArray *pointers;
+ // Pointers to other objects. Each link counts towards the reference count
+ // of the pointed-to object. To avoid memory leaks there should be no
+ // cycles in the reference graph.
+ GArray *links;
- // Serialized data, if available in memory (otherwise NULL).
+ // Serialized data, if available in memory (otherwise NULL), and a lock
+ // count which tracks if there are users that require the data to be kept
+ // around.
BlueSkyRCStr *data;
-} BlueSkyCloudLog;
+ int data_lock_count;
+};
/* Serialize objects into a log segment to be written to the cloud. */
struct _BlueSkyCloudLogState {
BlueSkyCloudID bluesky_cloudlog_id_from_string(const gchar *idstr);
void bluesky_cloudlog_ref(BlueSkyCloudLog *log);
void bluesky_cloudlog_unref(BlueSkyCloudLog *log);
+void bluesky_cloudlog_stats_update(BlueSkyCloudLog *log, int type);
void bluesky_cloudlog_sync(BlueSkyCloudLog *log);
void bluesky_cloudlog_insert(BlueSkyCloudLog *log);
-void bluesky_cloudlog_write_log(BlueSkyFS *fs);
+void bluesky_cloudlog_fetch(BlueSkyCloudLog *log);
+BlueSkyCloudPointer bluesky_cloudlog_serialize(BlueSkyCloudLog *log,
+ BlueSkyFS *fs);
+void bluesky_cloudlog_flush(BlueSkyFS *fs);
/* Logging infrastructure for ensuring operations are persistently recorded to
* disk. */
uint32_t crc32c_finalize(uint32_t crc);
struct _BlueSkyLog {
+ BlueSkyFS *fs;
char *log_directory;
GAsyncQueue *queue;
- int fd;
+ int fd, dirfd;
int seq_num;
+ GSList *committed;
+
+ /* The currently-open log file. */
+ BlueSkyCacheFile *current_log;
+
+ /* Cache of log segments which have been memory-mapped. */
+ GMutex *mmap_lock;
+ GHashTable *mmap_cache;
+
+ /* A count of the disk space consumed (in 1024-byte units) by all files
+ * tracked by mmap_cache (whether mapped or not, actually). */
+ gint disk_used;
+};
+
+/* An object for tracking log files which are stored locally--either the
+ * journal for filesystem consistency or log segments which have been fetched
+ * back from cloud storage. */
+struct _BlueSkyCacheFile {
+ GMutex *lock;
+ GCond *cond;
+ gint refcount;
+ int type; // Only one of CLOUDLOG_{JOURNAL,CLOUD}
+ int log_dir;
+ int log_seq;
+ char *filename; // Local filename, relateive to log directory
+ gint mapcount; // References to the mmaped data
+ const char *addr; // May be null if data is not mapped in memory
+ size_t len;
+ BlueSkyFS *fs;
+ BlueSkyLog *log;
+ gboolean fetching, ready; // Cloud data: downloading or ready for use
+ int64_t atime; // Access time, for cache management
+
+ /* Journal: Count of objects which are not yet committed to cloud storage
+ * but need to be; a non-zero value prevents the journal file from being
+ * deleted. */
+ gint dirty_refs;
};
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);
+BlueSkyRCStr *bluesky_log_map_object(BlueSkyFS *fs, int log_dir, int log_seq,
+ int log_offset, int log_size);
+void bluesky_mmap_unref(BlueSkyCacheFile *mmap);
+void bluesky_cachefile_unref(BlueSkyCacheFile *cachefile);
+
+BlueSkyCacheFile *bluesky_cachefile_lookup(BlueSkyFS *fs,
+ int clouddir, int log_seq);
+void bluesky_cachefile_gc(BlueSkyFS *fs);
#ifdef __cplusplus
}