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

From: Carlos Maiolino
Date: Mon Jan 13 2020 - 04:28:29 EST


On Sat, Jan 11, 2020 at 09:44:27AM +1100, Stephen Rothwell wrote:
> Hi Carlos,
>
> On Fri, 10 Jan 2020 12:03:53 +0100 Carlos Maiolino <cmaiolino@xxxxxxxxxx> wrote:
> >
> > Eitherway, I am not 100% sure this is the right fix for this case, I remember
> > some bmap() users who didn't need CONFIG_BLOCK, so we may still need to export
> > it without CONFIG_BLOCK.
> > Can you please send me your configuration?
>
> It was a x86_64 allnoconfig build.

Thanks for the info Stephen.

I think the correct way to fix this though, is to wrap the whole bmap(){}
definition in a #ifdef block, not only the EXPORT symbol, as, by my patches, we
redefine bmap() as an inline symbol if CONFIG_BLOCK is not set. So, something
like this:


diff --git a/fs/inode.c b/fs/inode.c
index 9f894b25af2b..21e58542801b 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1612,6 +1612,8 @@ EXPORT_SYMBOL(iput);
* Returns -EINVAL in case of error, 0 otherwise. If mapping falls into a
* hole, returns 0 and *block is also set to 0.
*/
+
+#ifdef CONFIG_BLOCK
int bmap(struct inode *inode, sector_t *block)
{
if (!inode->i_mapping->a_ops->bmap)
@@ -1621,6 +1623,7 @@ int bmap(struct inode *inode, sector_t *block)
return 0;
}
EXPORT_SYMBOL(bmap);
+#endif

/*
* With relative atime, only update atime if the previous atime is

So, we preserve the original inline definition in include/fs.h (making bmap()
just returning -EINVAL). What do you think?

Viro, mind to share your opinion? I can send a 'Fixes:' patch.

Cheers



--
Carlos