From mboxrd@z Thu Jan  1 00:00:00 1970
From: Matthew Wilcox <willy@debian.org>
Subject: Re: readdir within kernel
Date: Thu, 19 Dec 2002 13:09:52 +0000
Sender: linux-fsdevel-owner@vger.kernel.org
Message-ID: <20021219130952.O9994@parcelfarce.linux.theplanet.co.uk>
References: <20021219050632.GB16235@www.13thfloor.at>
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Cc: linux-fsdevel@vger.kernel.org
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To: Herbert Poetzl <herbert@13thfloor.at>
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In-Reply-To: <20021219050632.GB16235@www.13thfloor.at>; from herbert@13thfloor.at on Thu, Dec 19, 2002 at 06:06:32AM +0100
List-Id: linux-fsdevel.vger.kernel.org

On Thu, Dec 19, 2002 at 06:06:32AM +0100, Herbert Poetzl wrote:
> I would like to know if this is the right way to
> read a directory contents for a given directory
> dentry within a kernel module ...

well, you probably _shouldn't_ be anyway... but since you are, this is
how I did it for debugging why my system couldn't find /sbin/init.

diff -u -p -r1.11 main.c
--- init/main.c 10 Dec 2002 22:03:28 -0000      1.11
+++ init/main.c 19 Dec 2002 13:08:45 -0000
@@ -501,6 +501,26 @@ static void do_pre_smp_initcalls(void)
 
 extern void prepare_namespace(void);
 
+static int kernel_filler(void *buf, const char *name, int namlen, loff_t offset,
+                       ino_t ino, unsigned int d_type)
+{
+       printk("%.*s\n", namlen, name);
+}
+
+static void kernel_ls(char *name)
+{
+       struct file *file;
+
+       file = filp_open(name, O_RDONLY, 0);
+       if (!file) {
+               printk("Could not open %s\n", name);
+               return;
+       }
+
+       vfs_readdir(file, kernel_filler, NULL);
+       filp_close(file, current->files);
+}
+
 static int init(void * unused)
 {
        static char * argv_sh[] = { "sh", NULL, };
@@ -540,6 +560,9 @@ static int init(void * unused)
 
        (void) dup(0);
        (void) dup(0);
+
+       kernel_ls("/");
+       kernel_ls("/sbin");
        
        /*
         * We try each of these until one succeeds.


-- 
"It's not Hollywood.  War is real, war is primarily not about defeat or
victory, it is about death.  I've seen thousands and thousands of dead bodies.
Do you think I want to have an academic debate on this subject?" -- Robert Fisk