Merge tag 'for-5.8-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "Two refcounting fixes and one prepartory patch for upcoming splice
  cleanup:

   - fix double put of block group with nodatacow

   - fix missing block group put when remounting with discard=async

   - explicitly set splice callback (no functional change), to ease
     integrating splice cleanup patches"

* tag 'for-5.8-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: wire up iter_file_splice_write
  btrfs: fix double put of block group with nocow
  btrfs: discard: add missing put when grabbing block group from unused list

fs/btrfs/inode.c

@@ -1690,12 +1690,8 @@ out_check:
 			ret = fallback_to_cow(inode, locked_page, cow_start,
 					      found_key.offset - 1,
 					      page_started, nr_written);
-			if (ret) {
-				if (nocow)
-					btrfs_dec_nocow_writers(fs_info,
-								disk_bytenr);
+			if (ret)
 				goto error;
-			}
 			cow_start = (u64)-1;
 		}
 
@@ -1711,9 +1707,6 @@ out_check:
 					  ram_bytes, BTRFS_COMPRESS_NONE,
 					  BTRFS_ORDERED_PREALLOC);
 			if (IS_ERR(em)) {
-				if (nocow)
-					btrfs_dec_nocow_writers(fs_info,
-								disk_bytenr);
 				ret = PTR_ERR(em);
 				goto error;
 			}