Subject: linux-next: manual merge of the block tree with the btrfs tree

From: Stephen Rothwell <[email-masked]>
Date: Thu, 9 Jul 2020 12:58:16 +1000

Hi all,

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

  fs/btrfs/disk-io.c

between commit:

  16e1dd6a777e ("btrfs: preallocate anon block device at first phase of snapshot creation")

from the btrfs tree and commit:

  21cf86614504 ("writeback: remove bdi->congested_fn")

from the block 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 fs/btrfs/disk-io.c
index 08140caceb33,eb5f2506cede..000000000000
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@@ -1649,54 -1616,6 +1649,33 @@@ fail
  	return ERR_PTR(ret);
  }
  
 +/*
 + * Get in-memory reference of a root structure
 + *
 + * @objectid:	tree objectid
 + * @check_ref:	if set, verify that the tree exists and the item has at least
 + *		one reference
 + */
 +struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
 +				     u64 objectid, bool check_ref)
 +{
 +	return btrfs_get_root_ref(fs_info, objectid, 0, check_ref);
 +}
 +
 +/*
 + * Get in-memory reference of a root structure, created as new, optionally pass
 + * the anonymous block device id
 + *
 + * @objectid:	tree objectid
 + * @anon_dev:	if zero, allocate a new anonymous block device or use the
 + *		parameter value
 + */
 +struct btrfs_root *btrfs_get_new_fs_root(struct btrfs_fs_info *fs_info,
 +					 u64 objectid, dev_t anon_dev)
 +{
 +	return btrfs_get_root_ref(fs_info, objectid, anon_dev, true);
 +}
 +
- static int btrfs_congested_fn(void *congested_data, int bdi_bits)
- {
- 	struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
- 	int ret = 0;
- 	struct btrfs_device *device;
- 	struct backing_dev_info *bdi;
- 
- 	rcu_read_lock();
- 	list_for_each_entry_rcu(device, &info->fs_devices->devices, dev_list) {
- 		if (!device->bdev)
- 			continue;
- 		bdi = device->bdev->bd_bdi;
- 		if (bdi_congested(bdi, bdi_bits)) {
- 			ret = 1;
- 			break;
- 		}
- 	}
- 	rcu_read_unlock();
- 	return ret;
- }
- 
  /*
   * called by the kthread helper functions to finally call the bio end_io
   * functions.  This is where read checksum verification actually happens