From: Badari Pulavarty <pbadari@gmail.com>
Subject: Re: [patch 1/2] add init_ext4_proc() stub for when CONFIG_PROC_FS
	is not set
Date: Wed, 10 Oct 2007 08:30:10 -0700
Message-ID: <1192030210.12131.61.camel@dyn9047017100.beaverton.ibm.com>
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	 <20071009174012.GJ31713@thunk.org>  <20071010002203.GL31713@thunk.org>
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Cc: Mingming Cao <cmm@us.ibm.com>, markn@au1.ibm.com,
	ext4 <linux-ext4@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	"Amit K. Arora" <aarora@linux.vnet.ibm.com>,
	"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: Theodore Tso <tytso@mit.edu>
In-Reply-To: <20071010002203.GL31713@thunk.org>
Sender: linux-ext4-owner@vger.kernel.org

On Tue, 2007-10-09 at 20:22 -0400, Theodore Tso wrote:
> On Tue, Oct 09, 2007 at 01:40:12PM -0400, Theodore Tso wrote:
> > On Tue, Oct 09, 2007 at 10:03:06AM -0700, Mingming Cao wrote:
> > > I guess our testing did not catch this up because we have CONFIG_PROC_FS
> > > enabled all the time. mballoc needs procfs for exporting some stats info
> > > and tunable paramenters to optimize/customize multiple allocation.
> > > 
> > > We could select CONFIG_PROC_FS at kconfig when ext4dev is enabled.
> > 
> > We definitely should be able to compile without CONFIG_PROC_FS; it's a
> > major flaw in the mballoc-core.patch that it doesn't work without it.  
> 
> I will fold the following into mballoc-core.patch.  It's sufficient to
> allow us to compile w/o CONFIG_PROC_FS defined.
> 
> 							- Ted
> 
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index 4409c0c..2305af4 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -2854,9 +2854,11 @@ int __init init_ext4_proc(void)
>  	if (ext4_pspace_cachep == NULL)
>  		return -ENOMEM;
>  
> +#ifdef CONFIG_PROC_FS
>  	proc_root_ext4 = proc_mkdir(EXT4_ROOT, proc_root_fs);
>  	if (proc_root_ext4 == NULL)
>  		printk(KERN_ERR "EXT4-fs: Unable to create %s\n", EXT4_ROOT);
> +#endif
>  
>  	return 0;
>  }
> @@ -2865,7 +2867,9 @@ void exit_ext4_proc(void)
>  {
>  	/* XXX: synchronize_rcu(); */
>  	kmem_cache_destroy(ext4_pspace_cachep);
> +#ifdef CONFIG_PROC_FS
>  	remove_proc_entry(EXT4_ROOT, proc_root_fs);
> +#endif
>  }
>  

Its a good start. I think there are lots of proc handling routines that
can be move into #ifdef CONFIG_PROC_FS also.

All the code around ext4_mb_read_prealloc_table(),
ext4_mb_write_prealloc_table(), MB_PROC_VALUE_READ(stats),
MB_PROC_VALUE_WRITE(stats), .. can be ifdefed out.

Thanks,
Badari