* 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,
#define CLOUDLOG_JOURNAL 0x01
#define CLOUDLOG_CLOUD 0x02
#define CLOUDLOG_CACHE 0x04
-typedef struct {
+struct _BlueSkyCloudLog {
gint refcount;
GMutex *lock;
GCond *cond;
// 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 {
GString *data;
BlueSkyCloudPointer location;
GList *inode_list;
+ GSList *writeback_list; // Items which are being serialized right now
+ GList *pending_segments; // Segments which are being uploaded now
};
gboolean bluesky_cloudlog_equal(gconstpointer a, gconstpointer b);
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;
+
+ /* The smallest journal sequence number which may still contain data that
+ * must be preserved (since it it not yet in the cloud). */
+ int journal_watermark;
+};
+
+/* 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
};
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);
+
+/* Used to track log segments that are being written to the cloud. */
+typedef struct {
+ BlueSkyRCStr *data;
+ GSList *items;
+ GMutex *lock;
+ GCond *cond;
+ gboolean complete;
+} SerializedRecord;
+
+/***** Inode map management *****/
+
+/* Mapping information for a single inode number. These are grouped together
+ * into InodeMapRange objects. */
+typedef struct {
+ uint64_t inum;
+
+ /* The ID of the most recent version of the inode. */
+ BlueSkyCloudID id;
+
+ /* The location where that version is written in the cloud. */
+ BlueSkyCloudPointer location;
+
+ /* If the cloud log entry exists in memory, then a pointer to it, otherwise
+ * NULL. */
+ BlueSkyCloudLog *item;
+} InodeMapEntry;
+
+typedef struct {
+ /* Starting and ending inode number values that fall in this section.
+ * Endpoint values are inclusive. */
+ uint64_t start, end;
+
+ /* A sorted list (by inode number) of InodeMapEntry objects. */
+ GSequence *map_entries;
+
+ /* The location where this inode map section is stored in the cloud. */
+ BlueSkyCloudPointer location;
+
+ /* Have there been changes that require writing this section out again? */
+ gboolean dirty;
+} InodeMapRange;
+
+InodeMapEntry *bluesky_inode_map_lookup(GSequence *inode_map, uint64_t inum,
+ int action);
#ifdef __cplusplus
}