X-Git-Url: http://git.vrable.net/?a=blobdiff_plain;f=bluesky%2Fbluesky.h;h=ff2bf23b05ea87ab102a653cce0aca18d4fa9ca5;hb=348aaaad42163d6829112c9b18026c16b09e1914;hp=1d9f55c30007f403e6a71841b7229a560cd36b3e;hpb=b34b242b34388a3eb26bad5135cdf629ab69b70a;p=bluesky.git diff --git a/bluesky/bluesky.h b/bluesky/bluesky.h index 1d9f55c..ff2bf23 100644 --- a/bluesky/bluesky.h +++ b/bluesky/bluesky.h @@ -21,10 +21,36 @@ extern "C" { 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 { @@ -84,6 +110,10 @@ 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 @@ -96,6 +126,22 @@ typedef struct { 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. */ @@ -118,6 +164,13 @@ bluesky_time_hires bluesky_now_hires(); * 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; @@ -146,9 +199,18 @@ typedef struct { * 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; @@ -163,6 +225,9 @@ typedef struct { GHashTable *dirhash; /* Hash table by name for LOOKUP */ GHashTable *dirhash_folded; /* As above, but case-folded */ uint64_t parent_inum; /* inode for ".."; 0 if the root directory */ + + /* Symlink-specific fields */ + gchar *symlink_contents; } BlueSkyInode; /* A directory entry. The name is UTF-8 and is a freshly-allocated string. @@ -202,9 +267,12 @@ void bluesky_superblock_flush(BlueSkyFS *fs); 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); @@ -215,8 +283,6 @@ gboolean bluesky_directory_insert(BlueSkyInode *dir, const gchar *name, 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); @@ -230,6 +296,10 @@ gint bluesky_dirent_compare(gconstpointer a, gconstpointer b, 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 }