PERFORCE change 181755 for review

[Zheng Liu]

http://p4web.freebsd.org/@@181755?ac=10

Change 181755 by lz at gnehzuil-freebsd on 2010/08/03 08:28:18

	       Finished to read ext4 directory entry with hash directory index.
	
	       * Add two files. ext2_htree.[ch].
	       * The implementation of half md4 algorithm. We copy it from kern/md4c.c
	         and modify it because in Linux it uses a half md4 algorithm.
	       * Maybe there are two functions that need to be re-implemented because
	         they are very similar to Linux's implementation. Until now I don't
	         have a good implementation.
	
	       All of goals have been completed. Next I will test and clean my code.

Affected files ...

.. //depot/projects/soc2010/ext4fs/src/sys/fs/ext2fs/ext2_htree.c#1 add
.. //depot/projects/soc2010/ext4fs/src/sys/fs/ext2fs/ext2_htree.h#2 edit
.. //depot/projects/soc2010/ext4fs/src/sys/fs/ext2fs/ext2_lookup.c#5 edit

Differences ...

==== //depot/projects/soc2010/ext4fs/src/sys/fs/ext2fs/ext2_htree.h#2 (text+ko) ====

@@ -28,6 +28,15 @@
 #ifndef _FS_EXT2FS_EXT2_HTREE_H_
 #define _FS_EXT2FS_EXT2_HTREE_H_
 
+#define DIRINDEX_HASH_LEGACY            0
+#define DIRINDEX_HASH_HALF_MD4          1
+#define DIRINDEX_HASH_TEA               2
+#define DIRINDEX_HASH_LEGACY_UNSIGNED   3
+#define DIRINDEX_HASH_HALF_MD4_UNSIGNED 4
+#define DIRINDEX_HASH_TEA_UNSIGNED      5
+
+#define DIRINDEX_BAD_DIR -75000
+
 /*
  * define some data structures for hash directory index.
  */
@@ -68,9 +77,8 @@
 };
 
 struct dirindex_frame {
-        struct buffer *di_bp;
-        struct dirindex_entry *di_ent;
-        struct dirindex_entry *di_at;
+        struct dirindex_entry di_ent;
+        struct dirindex_entry di_at;
 };
 
 struct dirindex_map_entry {
@@ -79,4 +87,16 @@
         u_int16_t di_size;
 };
 
+struct dirindex_hash_info {
+        u_int32_t di_hash;
+        u_int32_t di_minhash;
+        int       di_hashversion;
+        u_int32_t *di_seed;
+};
+
+/* ext2_htree.c */
+int ext4_is_dirindex(struct inode *);
+int ext4_dirindex_lookup(struct vnode *, char *, int,
+                         doff_t *, struct buf **, doff_t *prevoffp);
+
 #endif /* !_FS_EXT2FS_EXT2_HTREE_H_ */

==== //depot/projects/soc2010/ext4fs/src/sys/fs/ext2fs/ext2_lookup.c#5 (text+ko) ====

@@ -60,6 +60,7 @@
 #include <fs/ext2fs/ext2_extern.h>
 #include <fs/ext2fs/ext2fs.h>
 #include <fs/ext2fs/ext2_dir.h>
+#include <fs/ext2fs/ext2_htree.h>
 
 #ifdef DIAGNOSTIC
 static int dirchk = 1;
@@ -348,6 +349,25 @@
 			cnp->cn_namelen + 3) &~ 3; */
 	}
 
+	bmask = VFSTOEXT2(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1;
+
+        /* Usr hash directory index to search a large direcotries. */
+        numdirpasses = 2;
+        prevoff = 0;
+        if (ext4_is_dirindex(dp)) {
+                switch (ext4_dirindex_lookup(vdp, cnp->cn_nameptr,
+                    cnp->cn_namelen, &i_offset, &bp, NULL)) {
+                case 0:
+                        ep = (struct ext2fs_direct_2 *)((char *)bp->b_data +
+                            (i_offset & bmask));
+                        entryoffsetinblock = i_offset;
+                        goto dirindex_found;
+                case ENOENT:
+                default:
+                        break;
+                }
+        }
+
 	/*
 	 * If there is cached information on a previous search of
 	 * this directory, pick up where we last left off.
@@ -359,7 +379,6 @@
 	 * profiling time and hence has been removed in the interest
 	 * of simplicity.
 	 */
-	bmask = VFSTOEXT2(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1;
 	if (nameiop != LOOKUP || i_diroff == 0 ||
 	    i_diroff > dp->i_size) {
 		entryoffsetinblock = 0;
@@ -462,6 +481,7 @@
 				 * reclen in ndp->ni_ufs area, and release
 				 * directory buffer.
 				 */
+dirindex_found:
 				ino = ep->e2d_ino;
 				goto found;
 			}