Add LRU lists for tracking inodes that are dirty/accessed.

[bluesky.git] / bluesky / bluesky.h

diff --git a/bluesky/bluesky.h b/bluesky/bluesky.h
index 3fc1c6a..59a33c5 100644 (file)
--- a/bluesky/bluesky.h
+++ b/bluesky/bluesky.h
@@ -122,6 +122,13 @@ typedef struct {
      * 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;
 } BlueSkyFS;
 
 /* Inode number of the root directory. */
@@ -185,6 +192,12 @@ typedef struct {
     /* 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;