Re: Linux 2.4.33-rc1

[Willy Tarreau <w@1wt.eu>]

Hi Grant,

On Sat, Jun 17, 2006 at 09:24:02AM +1000, Grant Coady wrote:
> On Sat, 17 Jun 2006 00:38:10 +0200, "Michal Piotrowski" <michal.k.k.piotrowski@gmail.com> wrote:
> 
> >Can you revert 42cce987d63d3048595b8b00d74be786707d5e5d commit?
> 
> Only if you point me at the patch, that string seems not to be 
> in the patch-2.4.33-rc1.gz file.

First, revert this one :

  http://kernel.org/git/?p=linux/kernel/git/marcelo/linux-2.4.git;a=commitdiff_plain;h=efc95599c0261dd7ab3a1d9071024ca140b4c644;hp=6601095e2de35f00325a33c8be6b548f81fe76d5

--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1479,19 +1479,20 @@ int vfs_unlink(struct inode *dir, struct
 {
 	int error;
 
-	double_down(&dir->i_zombie, &dentry->d_inode->i_zombie);
 	error = may_delete(dir, dentry, 0);
-	if (!error) {
-		error = -EPERM;
-		if (dir->i_op && dir->i_op->unlink) {
-			DQUOT_INIT(dir);
-			if (d_mountpoint(dentry))
-				error = -EBUSY;
-			else {
-				lock_kernel();
-				error = dir->i_op->unlink(dir, dentry);
-				unlock_kernel();
-			}
+	if (error)
+		return error;
+
+	double_down(&dir->i_zombie, &dentry->d_inode->i_zombie);
+	error = -EPERM;
+	if (dir->i_op && dir->i_op->unlink) {
+		DQUOT_INIT(dir);
+		if (d_mountpoint(dentry))
+			error = -EBUSY;
+		else {
+			lock_kernel();
+			error = dir->i_op->unlink(dir, dentry);
+			unlock_kernel();
 		}
 	}
 	double_up(&dir->i_zombie, &dentry->d_inode->i_zombie);


It will put you back to the state where all your machines hanged at boot
with -hf32.5, then revert this one :

  http://kernel.org/git/?p=linux/kernel/git/marcelo/linux-2.4.git;a=commitdiff_plain;h=f41e0ce901260d3d1ae5bd8bae34266891b4a65d;hp=925c7ce0a2d9a676cd8e4a2baf411b23cf6762d6

--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1479,7 +1479,7 @@ int vfs_unlink(struct inode *dir, struct
 {
 	int error;
 
-	down(&dir->i_zombie);
+	double_down(&dir->i_zombie, &dentry->d_inode->i_zombie);
 	error = may_delete(dir, dentry, 0);
 	if (!error) {
 		error = -EPERM;
@@ -1491,14 +1491,14 @@ int vfs_unlink(struct inode *dir, struct
 				lock_kernel();
 				error = dir->i_op->unlink(dir, dentry);
 				unlock_kernel();
-				if (!error)
-					d_delete(dentry);
 			}
 		}
 	}
-	up(&dir->i_zombie);
-	if (!error)
+	double_up(&dir->i_zombie, &dentry->d_inode->i_zombie);
+	if (!error) {
+		d_delete(dentry);
 		inode_dir_notify(dir, DN_DELETE);
+	}
 	return error;
 }
 
@@ -1607,18 +1607,19 @@ int vfs_link(struct dentry *old_dentry, 
 	struct inode *inode;
 	int error;
 
-	down(&dir->i_zombie);
 	error = -ENOENT;
 	inode = old_dentry->d_inode;
 	if (!inode)
-		goto exit_lock;
-
-	error = may_create(dir, new_dentry);
-	if (error)
-		goto exit_lock;
+		goto exit;
 
 	error = -EXDEV;
 	if (dir->i_dev != inode->i_dev)
+		goto exit;
+
+	double_down(&dir->i_zombie, &old_dentry->d_inode->i_zombie);
+
+	error = may_create(dir, new_dentry);
+	if (error)
 		goto exit_lock;
 
 	/*
@@ -1636,9 +1637,10 @@ int vfs_link(struct dentry *old_dentry, 
 	unlock_kernel();
 
 exit_lock:
-	up(&dir->i_zombie);
+	double_up(&dir->i_zombie, &old_dentry->d_inode->i_zombie);
 	if (!error)
 		inode_dir_notify(dir, DN_CREATE);
+exit:
 	return error;
 }
 

And you will have something equivalent to -hf32.6 (you remember, I only
reverted the fix in -hf32.6, and did not merge Marcelo's fix for the fix).
Then we will have to decide whether we can fix it again or revert it
completely. I would have liked to Cc: Vadim Egorov, but I cannot find his
email.

> Grant.

Cheers,
Willy