X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/43866e378188c25dd1e2208016ab3cbeb086ae6c..55e303ae13a4cf49d70f2294092726f2fffb9ef2:/bsd/ufs/ffs/fs.h

diff --git a/bsd/ufs/ffs/fs.h b/bsd/ufs/ffs/fs.h
index cffa4fad4..16871857e 100644
--- a/bsd/ufs/ffs/fs.h
+++ b/bsd/ufs/ffs/fs.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2003 Apple Computer, Inc. All rights reserved.
  *
  * @APPLE_LICENSE_HEADER_START@
  * 
@@ -140,16 +140,17 @@
  * computed as cylinder groups are inspected.
  * There is a 128-byte region in the superblock reserved for in-core
  * pointers to summary information. Originally this included an array
- * of pointers to blocks of struct csum; now there are just two
+ * of pointers to blocks of struct csum; now there are just three
  * pointers and the remaining space is padded with fs_ocsp[].
  *
  * NOCSPTRS determines the size of this padding. One pointer (fs_csp)
  * is taken away to point to a contiguous array of struct csum for
  * all cylinder groups; a second (fs_maxcluster) points to an array
- * of cluster sizes that is computed as cylinder groups are inspected.
+ * of cluster sizes that is computed as cylinder groups are inspected,
+ * and the third points to an array that tracks the creation of new
+ * directories.
  */
-#define NOCSPTRS ((128 / sizeof(void *)) - 2)
-
+#define NOCSPTRS ((128 / sizeof(void *)) - 3)
 
 /*
  * A summary of contiguous blocks of various sizes is maintained
@@ -174,6 +175,17 @@
 #define MINFREE		5
 #define DEFAULTOPT	FS_OPTTIME
 
+/* Grigoriy Orlov <gluk@ptci.ru> has done some extensive work to fine
+ * tune the layout preferences for directories within a filesystem.
+ * His algorithm can be tuned by adjusting the following parameters
+ * which tell the system the average file size and the average number
+ * of files per directory. These defaults are well selected for typical
+ * filesystems, but may need to be tuned for odd cases like filesystems
+ * being used for squid caches or news spools.
+ */
+#define AVFILESIZ	16384
+#define AFPDIR		64
+
 /*
  * Per cylinder group information; summarized in blocks allocated
  * from first cylinder group data blocks.  These blocks have to be
@@ -260,11 +272,14 @@ struct fs {
 /* these fields retain the current block allocation info */
 	int32_t	 fs_cgrotor;		/* last cg searched */
 	void    *fs_ocsp[NOCSPTRS];	/* list of fs_cs info buffers */
+	u_int8_t *fs_contigdirs;	/* # of contiguously allocated dirs */
 	struct	csum *fs_csp;		/* list of fs_cs info buffers */
 	int32_t	 *fs_maxcluster;	/* max cluster in each cyl group */
 	int32_t	 fs_cpc;		/* cyl per cycle in postbl */
 	int16_t	 fs_opostbl[16][8];	/* old rotation block list head */
-	int32_t	 fs_sparecon[50];	/* reserved for future constants */
+	int32_t  fs_avgfilesize;	/* expected average file size */
+	int32_t  fs_avgfpdir;		/* expected # of files per directory */
+	int32_t	 fs_sparecon[48];	/* reserved for future constants */
 	int32_t	 fs_contigsumsize;	/* size of cluster summary array */ 
 	int32_t	 fs_maxsymlinklen;	/* max length of an internal symlink */
 	int32_t	 fs_inodefmt;		/* format of on-disk inodes */