[Libsysio-commit] HEAD: libsysio/src inode.c

[Lee W. <lw...@us...>]

Update of /cvsroot/libsysio/libsysio/src
In directory sc8-pr-cvs1:/tmp/cvs-serv9577/src

Modified Files:
	inode.c 
Log Message:


Eliminated the i-node number field from the inode structure. We already
carry the file identifier so it was redundant. Problematic too, in that
it can be 32 or 64 bits in size.

This forced _sysio_i_new() and _sysio_i_find() to change -- They no longer
take the i-node number as an argument. Updated the driver calls to reflect
the new usage.

The i-node cache is now indexed by hashing the file identifier as opposed
to just using the, no longer maintained, i-node number. This caused
_sysio_i_find to become 2+ percent more expensive to use. Acceptable
for me.



Index: inode.c
===================================================================
RCS file: /cvsroot/libsysio/libsysio/src/inode.c,v
retrieving revision 1.10
retrieving revision 1.11
diff -u -w -b -B -p -r1.10 -r1.11
--- inode.c	8 Sep 2003 15:43:21 -0000	1.10
+++ inode.c	15 Oct 2003 18:00:57 -0000	1.11
@@ -171,6 +171,23 @@ i_reclaim()
 		max_inodes += t;
 }
 
+static unsigned
+hash(struct file_identifier *fid)
+{
+	size_t	n;
+	void	*p;
+	unsigned hkey;
+
+	n = fid->fid_len;
+	p = fid->fid_data;
+	hkey = 0;
+	do {
+		hkey <<= 1;
+		hkey += *(unsigned char *)p++;
+	} while (--n);
+	return hkey;
+}
+
 /*
  * Allocate and initialize a new i-node. Returned i-node is referenced.
  *
@@ -179,7 +196,6 @@ i_reclaim()
  */
 struct inode *
 _sysio_i_new(struct filesys *fs,
-	     ino_t inum,
 	     struct file_identifier *fid,
 	     mode_t type,
 	     dev_t rdev,
@@ -217,10 +233,10 @@ _sysio_i_new(struct filesys *fs,
 		ino->i_ops.inop_datasync = o->inop_datasync;
 		ino->i_ops.inop_ioctl = o->inop_ioctl;
 	}
-	I_INIT(ino, fs, inum, type, rdev, &ino->i_ops, fid, immunity, private);
+	I_INIT(ino, fs, type, rdev, &ino->i_ops, fid, immunity, private);
 	ino->i_ref = 1;
 	TAILQ_INSERT_TAIL(&_sysio_inodes, ino, i_nodes);
-	head = &fs->fs_itbl[inum % FS_ITBLSIZ];
+	head = &fs->fs_itbl[hash(fid) % FS_ITBLSIZ];
 	LIST_INSERT_HEAD(head, ino, i_link);
 
 	n_inodes++;
@@ -234,18 +250,17 @@ _sysio_i_new(struct filesys *fs,
  * and identifier.
  */
 struct inode *
-_sysio_i_find(struct filesys *fs, ino_t inum, struct file_identifier *fid)
+_sysio_i_find(struct filesys *fs, struct file_identifier *fid)
 {
 	struct inode *ino;
 	struct itable_entry *head;
 
-	head = &fs->fs_itbl[inum % FS_ITBLSIZ];
+	head = &fs->fs_itbl[hash(fid) % FS_ITBLSIZ];
 	/*
 	 * Look for existing.
 	 */
 	for (ino = head->lh_first; ino; ino = ino->i_link.le_next)
-		if (ino->i_num == inum &&
-		    ino->i_fid->fid_len == fid->fid_len &&
+		if (ino->i_fid->fid_len == fid->fid_len &&
 		    memcmp(ino->i_fid->fid_data,
 			   fid->fid_data,
 			   fid->fid_len) == 0) {