* created in a pending state, and not unlocked until the data is actually
* available.) */
int sync_inode_fetches;
+
+ /* Should frontends handle requests serially or allow operations to proceed
+ * in parallel? */
+ int sync_frontends;
} BlueSkyOptions;
extern BlueSkyOptions bluesky_options;
+/* Maximum number of threads to use in any particular thread pool, or -1 for no
+ * limit */
+extern int bluesky_max_threads;
+
+/* A general-purpose counter for gathering run-time statistics. */
+struct bluesky_stats {
+ const char *name;
+ int64_t count;
+ int64_t sum;
+};
+struct bluesky_stats *bluesky_stats_new(const char *name);
+void bluesky_stats_add(struct bluesky_stats *stats, int64_t value);
+void bluesky_stats_dump_all();
+
/* BlueSky status and error codes. Various frontends should translate these to
* the appropriate error code for whatever protocol they implement. */
typedef enum {
struct _BlueSkyStore;
typedef struct _BlueSkyStore BlueSkyStore;
+struct _BlueSkyLog;
+typedef struct _BlueSkyLog BlueSkyLog;
+
void bluesky_store_init();
BlueSkyStore *bluesky_store_new(const gchar *type);
void bluesky_store_free(BlueSkyStore *store);
uint64_t next_inum; /* Next available inode for allocation */
BlueSkyStore *store;
+ BlueSkyLog *log;
+
+ /* Accounting for memory used for caches. Space is measured in blocks, not
+ * bytes. We track both total data in the caches and dirty data (total
+ * data includes dirty data). Updates to these variables must be made
+ * atomically. */
+ gint cache_total, cache_dirty;
+
+ /* Linked list of inodes, sorted by access/modification times for cache
+ * management. Editing these lists is protected by the filesystem lock; to
+ * avoid deadlock do not attempt to take any other locks while the FS lock
+ * is held for list editing purposes. Items at the head of the list are
+ * most recently accessed/modified. */
+ GList dirty_list, accessed_list;
+
+ /* Mutex for the flush daemon, to prevent concurrent execution. */
+ GMutex *flushd_lock;
+
+ /* Mapping of object identifiers (blocks, inodes) to physical location (in
+ * the local cache or in the logs in the cloud). */
+ GHashTable *locations;
} BlueSkyFS;
/* Inode number of the root directory. */
/* change_count is increased with every operation which modifies the inode,
* and can be used to determine if cached data is still valid.
* change_commit is the value of change_count when the inode was last
- * committed to stable storage. */
- uint64_t change_count, change_commit;
+ * committed to stable storage (the log).
+ * change_cloud tracks which version was last commited to cloud storage. */
+ uint64_t change_count, change_commit, change_cloud;
/* Timestamp for controlling when modified data is flushed to stable
* storage. When an inode is first modified from a clean state, this is
* set to the current time. If the inode is clean, it is set to zero. */
int64_t change_time;
+ /* Last access time to this inode, for controlling cache evictions. */
+ int64_t access_time;
+
/* Additional state for tracking cache writeback status. */
uint64_t change_pending; /* change_count version currently being committed to storage */
+ /* Pointers to the linked-list elements for this inode in the accessed and
+ * dirty linked lists. We re-use the GList structure, using ->next to
+ * point to the head of the list and ->prev to point to the tail. The data
+ * element is unused. */
+ GList *accessed_list, *dirty_list;
+
int64_t atime; /* Microseconds since the Unix epoch */
int64_t ctime;
int64_t mtime;
BlueSkyFS *bluesky_init_fs(gchar *name, BlueSkyStore *store);
void bluesky_superblock_flush(BlueSkyFS *fs);
+gboolean bluesky_inode_is_ready(BlueSkyInode *inode);
+
int64_t bluesky_get_current_time();
void bluesky_inode_update_ctime(BlueSkyInode *inode, gboolean update_mtime);
uint64_t bluesky_fs_alloc_inode(BlueSkyFS *fs);
uint64_t inum);
void bluesky_directory_dump(BlueSkyInode *dir);
-void bluesky_block_touch(BlueSkyInode *inode, uint64_t i);
-void bluesky_block_fetch(BlueSkyFS *fs, BlueSkyBlock *block);
void bluesky_file_truncate(BlueSkyInode *inode, uint64_t size);
void bluesky_file_write(BlueSkyInode *inode, uint64_t offset,
const char *data, gint len);
gpointer unused);
void bluesky_flushd_invoke(BlueSkyFS *fs);
+void bluesky_flushd_invoke_conditional(BlueSkyFS *fs);
void bluesky_inode_do_sync(BlueSkyInode *inode);
+void bluesky_flushd_thread_launch(BlueSkyFS *fs);
void bluesky_debug_dump(BlueSkyFS *fs);