Btrfs: extent_map and data=ordered fixes for space balancing
* Add an EXTENT_BOUNDARY state bit to keep the writepage code
from merging data extents that are in the process of being
relocated. This allows us to do accounting for them properly.
* The balancing code relocates data extents indepdent of the underlying
inode. The extent_map code was modified to properly account for
things moving around (invalidating extent_map caches in the inode).
* Don't take the drop_mutex in the create_subvol ioctl. It isn't
required.
* Fix walking of the ordered extent list to avoid races with sys_unlink
* Change the lock ordering rules. Transaction start goes outside
the drop_mutex. This allows btrfs_commit_transaction to directly
drop the relocation trees.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 3cb411a..c9d1908 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -15,6 +15,7 @@
#define EXTENT_BUFFER_FILLED (1 << 8)
#define EXTENT_ORDERED (1 << 9)
#define EXTENT_ORDERED_METADATA (1 << 10)
+#define EXTENT_BOUNDARY (1 << 11)
#define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK)
/*