git://linux-nfs.org/~bhalevy/linux-pnfs.git
On Tue, Feb 24, 2009 at 2:19 PM, Randy Dunlap <randy.dunlap@xxxxxxxxxx> wrote:
> Fred Isaman wrote:
>> The pnfs tree base of of 2.6.29-rc5 uses the new find_last_bit
>
> Where is the pnfs tree?
git://linux-nfs.org/~bhalevy/linux-pnfs.git
branch origin/pnfs-2.6.29
>
>> function (defined in
>> lib/find_last_bit.c) in a file in the fs/nfs directory. Myself and
>> another developer (though no one else so far) get the following error
>> during compile:
>>
>> Kernel: arch/x86/boot/bzImage is ready (#5)
>> Building modules, stage 2.
>> MODPOST 515 modules
>> ERROR: "find_last_bit" [fs/nfs/nfs.ko] undefined!
>> make[2]: *** [__modpost] Error 1
>> make[1]: *** [modules] Error 2
>> make: *** [sub-make] Error 2
>>
>>
>> Note that find_last_bit() is not used in any file in the fs directory.
>> If I add it to any function that is EXPORT_SYMBOL'ed
>> from the fs directory, suddenly the compile errors go away. (See the
>> below patch for a more concrete example.)
>>
>> I am not sure what is going on, and why it only affects some
>> developers, but it looks a lot like the kbuild system
>> is deciding that the library does not need to be included at the fs
>> directory level, so isn't including it in fs/nfs where
>> it is needed.
>>
>> Thanks for any help.
>> Fred
>
> A failing .config file would be helpful.
>
I've attached the .config
> Is CONFIG_GENERIC_FIND_LAST_BIT set in your .config file?
>
yes
> If you change lib/Makefile like this:
> -lib-$(CONFIG_GENERIC_FIND_LAST_BIT) += find_last_bit.o
> +obj-$(CONFIG_GENERIC_FIND_LAST_BIT) += find_last_bit.o
>
> i.e., s/lib/obj/, does your build succeed?
>
Yes, it does work with that change.
Fred
>
>> From 4bd89543983640ab01c9b704d427f83dad3aa455 Mon Sep 17 00:00:00 2001
>> From: Fred Isaman <iisaman@xxxxxxxxxxxxxx>
>> Date: Fri, 20 Feb 2009 11:58:52 -0500
>> Subject: [PATCH 1/1] DEBUG: Need this to compile - what the heck?
>>
>> This looks suspiciously like a bug in the kbuild system, where
>> the library include is not passed down to fs/nfs unless it is
>> used by fs. Without this, I get the following error during linking:
>>
>> Kernel: arch/x86/boot/bzImage is ready (#5)
>> Building modules, stage 2.
>> MODPOST 515 modules
>> ERROR: "find_last_bit" [fs/nfs/nfs.ko] undefined!
>> make[2]: *** [__modpost] Error 1
>> make[1]: *** [modules] Error 2
>> make: *** [sub-make] Error 2
>>
>> Signed-off-by: Fred Isaman <iisaman@xxxxxxxxxxxxxx>
>> ---
>> fs/inode.c | 1 +
>> 1 files changed, 1 insertions(+), 0 deletions(-)
>>
>> diff --git a/fs/inode.c b/fs/inode.c
>> index 306faef..a4e29b3 100644
>> --- a/fs/inode.c
>> +++ b/fs/inode.c
>> @@ -226,6 +226,7 @@ EXPORT_SYMBOL(destroy_inode);
>> */
>> void inode_init_once(struct inode *inode)
>> {
>> + find_last_bit((unsigned long *) inode, 5);
>> memset(inode, 0, sizeof(*inode));
>> INIT_HLIST_NODE(&inode->i_hash);
>> INIT_LIST_HEAD(&inode->i_dentry);
>> --
>
> --
> ~Randy
>
Attachment:
.config
Description: Binary data
