On Tue, Dec 15, 2015 at 07:09:48PM +0800, Zhao Lei wrote:

__btrfs_map_block() should return all mirror on WRITE,
REQ_GET_READ_MIRRORS, and RECOVERY case, whether need_raid_map set
or not.

need_raid_map only used to control is to set bbio->raid_map.

Current code works right becuase there is only one caller can
trigger above bug, which is readahead, and this function happened
to bypass on less mirror.

But after we fixed __btrfs_map_block(), readahead will be really
works, and exit with warning at another bug.
This patchset fixed __btrfs_map_block(), and disable raid56
readahead temp temporary, (actually, it already disable by this bug),
and I'll fix raid56 readahead next.

Zhao Lei (4):
  btrfs: Disable raid56 readahead
  btrfs: return all mirror whether need_raid_map set or not
  btrfs: Small cleanup for get index_srcdev loop
  btrfs: Use direct way to determine raid56 write/recover mode

Are these patches still relevant? If yes, please update and resed,
thanks.