[PATCH 2.6.5-mm4] vfs_readdir optimizations

[PATCH 2.6.5-mm4] vfs_readdir optimizations

[Fabian Frederick]

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-Remove unuseful gotos
-ENOENT case on DEADDIR

PS : mm5 doesn't appear on kernel.org main page.

Regards,
Fabian


[-- Attachment #2: readdir1.diff --]
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diff -Naur orig/fs/readdir.c edited/fs/readdir.c
--- orig/fs/readdir.c	2004-04-04 05:37:06.000000000 +0200
+++ edited/fs/readdir.c	2004-04-12 17:25:36.000000000 +0200
@@ -21,21 +21,16 @@
 {
 	struct inode *inode = file->f_dentry->d_inode;
 	int res = -ENOTDIR;
-	if (!file->f_op || !file->f_op->readdir)
-		goto out;
-
-	res = security_file_permission(file, MAY_READ);
-	if (res)
-		goto out;
-
-	down(&inode->i_sem);
-	res = -ENOENT;
-	if (!IS_DEADDIR(inode)) {
-		res = file->f_op->readdir(file, buf, filler);
-		file_accessed(file);
+	if (file->f_op && file->f_op->readdir){
+		if (!(res = security_file_permission(file, MAY_READ))){
+			down(&inode->i_sem);
+			if (!IS_DEADDIR(inode)) {
+				res = file->f_op->readdir(file, buf, filler);
+				file_accessed(file);
+			}else   res = -ENOENT;
+			up(&inode->i_sem);
+		}
 	}
-	up(&inode->i_sem);
-out:
 	return res;
 }
 

Re: [PATCH 2.6.5-mm4] vfs_readdir optimizations

[Chris Wright]

* Fabian Frederick (Fabian.Frederick@skynet.be) wrote:
> -Remove unuseful gotos
> -ENOENT case on DEADDIR

Couple things.  It's useful to generate some numbers to show an
optimization is worthwhile.  And code readability/maintainability is
important to maintain correctness.  You may look at the assembly and
find that there is no real optimization with the changes you've proposed.

thanks,
-chris
-- 
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