[PATCH] 2.5.50: unused code in link_path_walk()

[Matthew Wilcox]

@@ -700,7 +700,6 @@
if (this.name[1] != '.')
break;
follow_dotdot(&nd->mnt, &nd->dentry);
- inode = nd->dentry->d_inode;
/* fallthrough */
case 1:
goto return_base;

seems broken to me. if follow_dotdot() changes nd->dentry (can happen!),
inode needs to be changed. look:

inode = nd->dentry->d_inode;
for(;;) {
err = exec_permission_lite(inode);
if (this.name[0] == '.') switch (this.len) {
case 2:
if (this.name[1] != '.')
break;
follow_dotdot(&nd->mnt, &nd->dentry);
inode = nd->dentry->d_inode;
/* fallthrough */
case 1:
continue;
}
}

btw, you should cc linux-fsdevel for patches to the VFS.

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[Olaf Dietsche]

Matthew Wilcox <wi...@debian.org> writes:

> @@ -700,7 +700,6 @@
> if (this.name[1] != '.')
> break;
> follow_dotdot(&nd->mnt, &nd->dentry);
> - inode = nd->dentry->d_inode;
> /* fallthrough */
> case 1:
> goto return_base;
>
> seems broken to me. if follow_dotdot() changes nd->dentry (can happen!),
> inode needs to be changed. look:
>
> inode = nd->dentry->d_inode;
> for(;;) {
> err = exec_permission_lite(inode);
> if (this.name[0] == '.') switch (this.len) {
> case 2:
> if (this.name[1] != '.')
> break;
> follow_dotdot(&nd->mnt, &nd->dentry);
> inode = nd->dentry->d_inode;
> /* fallthrough */
> case 1:
> continue;
> }
> }

You looked at the _first_ switch statement. You must go further down
to the _second_ switch. *There*, you don't need this assignment, AFAICS.

> btw, you should cc linux-fsdevel for patches to the VFS.

Thanks for this pointer, I'll spam linux-fsdevel in the future ;-).

Regards, Olaf.