Btrfs: make btrfs_map_block() return entire free extent for each device of RAID0/1/10/DUP

btrfs_map_block() will only return a single stripe length, but we want the
full extent be mapped to each disk when we are trimming the extent,
so we add length to btrfs_bio_stripe and fill it if we are mapping for REQ_DISCARD.

Signed-off-by: Li Dongyang <lidongyang@novell.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 7b38d0668b51..cc2eadaf7a27 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -126,6 +126,7 @@ struct btrfs_fs_devices {
 struct btrfs_bio_stripe {
         struct btrfs_device *dev;
         u64 physical;
+        u64 length; /* only used for discard mappings */
 };
 
 struct btrfs_multi_bio {