linux-next: build failure after merge of the ext4 tree

linux-next: build failure after merge of the ext4 tree

[Stephen Rothwell]

Hi Theodore,

After merging the ext4 tree, today's linux-next build (x86_64
allmodconfig) failed like this:

ERROR: "wbc_account_io" [fs/ext4/ext4.ko] undefined!
ERROR: "bio_associate_blkcg" [fs/ext4/ext4.ko] undefined!

Caused by commit

  001e4a8775f6 ("ext4: implement cgroup writeback support")

I have used the ext4 tree from next-20150722 for today.

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au

Re: linux-next: build failure after merge of the ext4 tree

[Theodore Ts'o]

On Thu, Jul 23, 2015 at 10:56:23AM +1000, Stephen Rothwell wrote:
> Hi Theodore,
> 
> After merging the ext4 tree, today's linux-next build (x86_64
> allmodconfig) failed like this:
> 
> ERROR: "wbc_account_io" [fs/ext4/ext4.ko] undefined!
> ERROR: "bio_associate_blkcg" [fs/ext4/ext4.ko] undefined!
> 
> Caused by commit
> 
>   001e4a8775f6 ("ext4: implement cgroup writeback support")
> 
> I have used the ext4 tree from next-20150722 for today.

Ah, I see, we're missing the include files which define the inline
dummy functions.  I'll fix this in my tree, thanks.

      		       	   	      	    - Ted

Re: linux-next: build failure after merge of the ext4 tree

[Theodore Ts'o]

On Thu, Jul 23, 2015 at 12:49:53PM -0400, Theodore Ts'o wrote:
> > After merging the ext4 tree, today's linux-next build (x86_64
> > allmodconfig) failed like this:
> > 
> > ERROR: "wbc_account_io" [fs/ext4/ext4.ko] undefined!
> > ERROR: "bio_associate_blkcg" [fs/ext4/ext4.ko] undefined!
> > 
> > Caused by commit
> > 
> >   001e4a8775f6 ("ext4: implement cgroup writeback support")
> > 
> > I have used the ext4 tree from next-20150722 for today.
> 
> Ah, I see, we're missing the include files which define the inline
> dummy functions.  I'll fix this in my tree, thanks.

Whoops, correction, the problem is that wbc_account_io() and
bio_asociate_blkcg() need to be exported as symbols.

Tejun, how quickly get you get a fix into linux-next?  Or should I
just drop that patch for now?

						- Ted
						

Re: linux-next: build failure after merge of the ext4 tree

[Tejun Heo]

On Thu, Jul 23, 2015 at 01:23:43PM -0400, Theodore Ts'o wrote:
> On Thu, Jul 23, 2015 at 12:49:53PM -0400, Theodore Ts'o wrote:
> > > After merging the ext4 tree, today's linux-next build (x86_64
> > > allmodconfig) failed like this:
> > > 
> > > ERROR: "wbc_account_io" [fs/ext4/ext4.ko] undefined!
> > > ERROR: "bio_associate_blkcg" [fs/ext4/ext4.ko] undefined!
> > > 
> > > Caused by commit
> > > 
> > >   001e4a8775f6 ("ext4: implement cgroup writeback support")
> > > 
> > > I have used the ext4 tree from next-20150722 for today.
> > 
> > Ah, I see, we're missing the include files which define the inline
> > dummy functions.  I'll fix this in my tree, thanks.
> 
> Whoops, correction, the problem is that wbc_account_io() and
> bio_asociate_blkcg() need to be exported as symbols.
> 
> Tejun, how quickly get you get a fix into linux-next?  Or should I
> just drop that patch for now?

I'll send the patch to add EXPORT to Jens right away.

Thanks.

-- 
tejun

[PATCH block/for-linus] block: export bio_associate_*() and wbc_account_io()

[Tejun Heo]

bio_associate_blkcg(), bio_associate_current() and wbc_account_io()
are used to implement cgroup writeback support for filesystems and
thus need to be exported.  Export them.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
---
Hello, Jens.

While this change isn't strictly necessary for 4.2, I think it'd
better to push it through for-linus so that it's there before any
filesystem specific changes are merged.

Thanks.

 block/bio.c       |    2 ++
 fs/fs-writeback.c |    1 +
 2 files changed, 3 insertions(+)

--- a/block/bio.c
+++ b/block/bio.c
@@ -2009,6 +2009,7 @@ int bio_associate_blkcg(struct bio *bio,
 	bio->bi_css = blkcg_css;
 	return 0;
 }
+EXPORT_SYMBOL_GPL(bio_associate_blkcg);
 
 /**
  * bio_associate_current - associate a bio with %current
@@ -2039,6 +2040,7 @@ int bio_associate_current(struct bio *bi
 	bio->bi_css = task_get_css(current, blkio_cgrp_id);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(bio_associate_current);
 
 /**
  * bio_disassociate_task - undo bio_associate_current()
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -702,6 +702,7 @@ void wbc_account_io(struct writeback_con
 	else
 		wbc->wb_tcand_bytes -= min(bytes, wbc->wb_tcand_bytes);
 }
+EXPORT_SYMBOL_GPL(wbc_account_io);
 
 /**
  * inode_congested - test whether an inode is congested

Re: [PATCH block/for-linus] block: export bio_associate_*() and wbc_account_io()

[Chris Mason]

On Thu, Jul 23, 2015 at 02:27:09PM -0400, Tejun Heo wrote:
> bio_associate_blkcg(), bio_associate_current() and wbc_account_io()
> are used to implement cgroup writeback support for filesystems and
> thus need to be exported.  Export them.

Thanks, these were the only three I needed on the btrfs side.

-chris

Re: [PATCH block/for-linus] block: export bio_associate_*() and wbc_account_io()

[Jens Axboe]

On 07/23/2015 12:27 PM, Tejun Heo wrote:
> bio_associate_blkcg(), bio_associate_current() and wbc_account_io()
> are used to implement cgroup writeback support for filesystems and
> thus need to be exported.  Export them.
>
> Signed-off-by: Tejun Heo <tj@kernel.org>
> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
> ---
> Hello, Jens.
>
> While this change isn't strictly necessary for 4.2, I think it'd
> better to push it through for-linus so that it's there before any
> filesystem specific changes are merged.

Might as well shove it it, as it'll make the lives of others easier.

-- 
Jens Axboe