tree cd20c904dd016ab031af582dadfbd6e04bf4df9e
parent 168fd7d271d9d8e81ff0b03eb08c36d82670c8a9
author Chris Mason <chris.mason@oracle.com> 1214424090 -0400
committer Chris Mason <chris.mason@oracle.com> 1222355043 -0400

Btrfs: Add a skip_locking parameter to struct path, and make various funcs honor it

Allocations may need to read in block groups from the extent allocation tree,
which will require a tree search and take locks on the extent allocation
tree.  But, those locks might already be held in other places, leading
to deadlocks.

Since the alloc_mutex serializes everything right now, it is safe to
skip the btree locking while caching block groups.  A better fix will be
to either create a recursive lock or find a way to back off existing
locks while caching block groups.

Signed-off-by: Chris Mason <chris.mason@oracle.com>