xnu-792.1.5.tar.gz

[apple/xnu.git] / bsd / hfs / hfs_catalog.h

diff --git a/bsd/hfs/hfs_catalog.h b/bsd/hfs/hfs_catalog.h
index 9914785586b0e62766871cc2ef79840613f7ff9d..63c2fe994850440e8f3d1cda8868edc0f5bd51f9 100644 (file)
--- a/bsd/hfs/hfs_catalog.h
+++ b/bsd/hfs/hfs_catalog.h
@@ -118,13 +118,20 @@ struct cat_fork {
  *
  */
 struct directoryhint {
-       SLIST_ENTRY(directoryhint) dh_link; /* chain */
+       TAILQ_ENTRY(directoryhint) dh_link; /* chain */
        int     dh_index;                   /* index into directory (zero relative) */
        u_int32_t  dh_time;
        struct  cat_desc  dh_desc;          /* entry's descriptor */
 };
 typedef struct directoryhint directoryhint_t;
 
+/* 
+ * HFS_MAXDIRHINTS cannot be larger than 63 without reducing
+ * HFS_INDEX_BITS, because given the 6-bit tag, at most 63 different
+ * tags can exist.  When HFS_MAXDIRHINTS is larger than 63, the same
+ * list may contain dirhints of the same tag, and a staled dirhint may
+ * be returned.
+ */
 #define HFS_MAXDIRHINTS 32
 #define HFS_DIRHINT_TTL 45