Subject: linux-next: manual merge of the nvdimm tree with the xfs tree

From: Stephen Rothwell <[email-masked]>
Date: Fri, 1 Jun 2018 18:58:46 +1000

Hi Dan,

Today's linux-next merge of the nvdimm tree got a conflict in:

  drivers/dax/super.c

between commits:

  ba23cba9b3bd ("fs: allow per-device dax status checking for filesystems")
  80660f20252d ("dax: change bdev_dax_supported() to support boolean returns")

from the xfs tree and commit:

  e76384884344 ("mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS")

from the nvdimm tree.

I fixed it up (see below) and can carry the fix as necessary. This
is now fixed as far as linux-next is concerned, but any non trivial
conflicts should be mentioned to your upstream maintainer when your tree
is submitted for merging.  You may also want to consider cooperating
with the maintainer of the conflicting tree to minimise any particularly
complex conflicts.

-- 
Cheers,
Stephen Rothwell
diff --cc drivers/dax/super.c
index 1d7bd96511f0,88672b6f6252..000000000000
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@@ -80,11 -80,13 +80,12 @@@ EXPORT_SYMBOL_GPL(fs_dax_get_by_bdev)
   * This is a library function for filesystems to check if the block device
   * can be mounted with dax option.
   *
 - * Return: negative errno if unsupported, 0 if supported.
 + * Return: true if supported, false if unsupported
   */
 -int __bdev_dax_supported(struct super_block *sb, int blocksize)
 +bool __bdev_dax_supported(struct block_device *bdev, int blocksize)
  {
 -	struct block_device *bdev = sb->s_bdev;
  	struct dax_device *dax_dev;
+ 	bool dax_enabled = false;
  	pgoff_t pgoff;
  	int err, id;
  	void *kaddr;
@@@ -134,15 -135,22 +135,22 @@@
  		 * on being able to do (page_address(pfn_to_page())).
  		 */
  		WARN_ON(IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API));
+ 		dax_enabled = true;
  	} else if (pfn_t_devmap(pfn)) {
- 		/* pass */;
- 	} else {
+ 		struct dev_pagemap *pgmap;
+ 
+ 		pgmap = get_dev_pagemap(pfn_t_to_pfn(pfn), NULL);
+ 		if (pgmap && pgmap->type == MEMORY_DEVICE_FS_DAX)
+ 			dax_enabled = true;
+ 		put_dev_pagemap(pgmap);
+ 	}
+ 
+ 	if (!dax_enabled) {
 -		pr_debug("VFS (%s): error: dax support not enabled\n",
 -				sb->s_id);
 +		pr_debug("%s: error: dax support not enabled\n",
 +				bdevname(bdev, buf));
- 		return false;
+ 		return -EOPNOTSUPP;
  	}
- 
- 	return true;
+ 	return 0;
  }
  EXPORT_SYMBOL_GPL(__bdev_dax_supported);
  #endif