typedef struct {
/* Perform all get/put operations synchronously. */
int synchronous_stores;
+
+ /* Write data in cache immediately after file is modified. */
+ int writethrough_cache;
+
+ /* Can inodes be fetched asynchronously? (Inode object is initially
+ * 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 {
BLUESKY_SYMLINK = 5,
BLUESKY_SOCKET = 6,
BLUESKY_FIFO = 7,
+
+ /* Special types used only internally. */
+ BLUESKY_PENDING = 0, /* Inode being loaded; type not yet determined */
+ BLUESKY_INVALID = -1, /* Inode is invalid (failed to load) */
} BlueSkyFileType;
/* Filesystem state. Each filesystem which is exported is represented by a
uint64_t next_inum; /* Next available inode for allocation */
BlueSkyStore *store;
+
+ /* 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;
} BlueSkyFS;
/* Inode number of the root directory. */
* dropping from the cache.
* - Any pending operations should hold extra references to the inode as
* appropriate to keep it available until the operation completes.
+ * - Locking dependency order is, when multiple locks are to be acquired, to
+ * acquire locks on parents in the filesystem tree before children.
+ * (TODO: What about rename when we acquire locks in unrelated parts of the
+ * filesystem?)
+ * - An inode should not be locked while the filesystem lock is already held,
+ * since some code may do an inode lookup (which acquires the filesystem
+ * lock) while a different inode is locked.
* */
typedef struct {
GMutex *lock;
* 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;
int64_t bluesky_get_current_time();
void bluesky_inode_update_ctime(BlueSkyInode *inode, gboolean update_mtime);
uint64_t bluesky_fs_alloc_inode(BlueSkyFS *fs);
+void bluesky_init_inode(BlueSkyInode *i, BlueSkyFileType type);
BlueSkyInode *bluesky_new_inode(uint64_t inum, BlueSkyFS *fs, BlueSkyFileType type);
BlueSkyInode *bluesky_get_inode(BlueSkyFS *fs, uint64_t inum);
+void bluesky_inode_ref(BlueSkyInode *inode);
+void bluesky_inode_unref(BlueSkyInode *inode);
void bluesky_insert_inode(BlueSkyFS *fs, BlueSkyInode *inode);
void bluesky_dirent_destroy(gpointer dirent);
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_debug_dump(BlueSkyFS *fs);
#ifdef __cplusplus
}
projects / bluesky.git / blobdiff