[Dazuko-help] 2.0.5-pre4 posted

[John Ogness]

Hi,

I have posted another pre-release of 2.0.5. The last pre-release caused 
a lot of problems with the __d_path() function (specifically, with 
vfsmount_lock). This turns out to be a much bigger problem than I first 
thought.

The problem: __d_path(), a critical function for performing full path 
name lookups, is not exported to kernel modules. Dazuko could have its 
own copy of this function except that the function uses a kernel lock 
(vfsmount_lock) that is also not exported to kernel modules.

The solution: On non-SMP kernels the lock is irrelevant because non-SMP 
kernels don't use kernel locks. This means that for non-SMP kernels, 
Dazuko can use an internal copy of the __d_path() function. However, SMP 
kernels do need kernel locks and therefore *must* use the "real" 
__d_path() function in the kernel. In order to do this, the __d_path() 
function must be exported. A very small kernel patch is now provided 
with the Dazuko package to export the function.

For SMP kernels, this means that the kernel source must be patched and a 
new kernel built. I hate this as much as you do, but there is no way 
around it. Some distributions (such as Fedora Core) already export 
__d_path(), so a kernel patch/rebuild isn't necessary. Hopefully more 
distributions (and maybe even the "vanilla" kernel) will once again 
export this function.

Also included in the Dazuko package is a README.linux26 file that 
explains this. The "configure" script also produces a warning if you 
have an SMP kernel and suggests reading the README.linux26 file.

I am open for comments/suggestions about this. I don't know what else to do.

I normally don't post these announcements to dazuko-help, but I felt 
that this information was important (although a bit technical).

John Ogness

--
Dazuko Maintainer