Btrfs: Replace the big fs_mutex with a collection of other locks

Extent alloctions are still protected by a large alloc_mutex.
Objectid allocations are covered by a objectid mutex
Other btree operations are protected by a lock on individual btree nodes

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

1 files changed, 3 insertions, 2 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 50891b39f366..692b8ea42de1 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -519,9 +519,9 @@ struct btrfs_fs_info {
         struct backing_dev_info bdi;
         spinlock_t hash_lock;
         struct mutex trans_mutex;
-        struct mutex fs_mutex;
         struct mutex alloc_mutex;
         struct mutex chunk_mutex;
+        struct mutex drop_mutex;
         struct list_head trans_list;
         struct list_head hashers;
         struct list_head dead_roots;
@@ -554,7 +554,7 @@ struct btrfs_fs_info {
         struct completion kobj_unregister;
         int do_barriers;
         int closing;
-        unsigned long throttles;
+        atomic_t throttles;
 
         u64 total_pinned;
         struct list_head dirty_cowonly_roots;
@@ -594,6 +594,7 @@ struct btrfs_root {
         struct inode *inode;
         struct kobject root_kobj;
         struct completion kobj_unregister;
+        struct mutex objectid_mutex;
         u64 objectid;
         u64 last_trans;