Btrfs: add and improve comments

This improves the comments at the top of many functions.  It didn't
dive into the guts of functions because I was trying to
avoid merging problems with the new allocator and back reference work.

extent-tree.c and volumes.c were both skipped, and there is definitely
more work todo in cleaning and commenting the code.

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

1 files changed, 5 insertions, 2 deletions

diff --git a/fs/btrfs/async-thread.h b/fs/btrfs/async-thread.h
index 43e44d115dd1..4ec9a2ee0f9d 100644
--- a/fs/btrfs/async-thread.h
+++ b/fs/btrfs/async-thread.h
@@ -63,14 +63,17 @@ struct btrfs_workers {
         /* once a worker has this many requests or fewer, it is idle */
         int idle_thresh;
 
-        /* list with all the work threads */
+        /* list with all the work threads.  The workers on the idle thread
+         * may be actively servicing jobs, but they haven't yet hit the
+         * idle thresh limit above.
+         */
         struct list_head worker_list;
         struct list_head idle_list;
 
         /* lock for finding the next worker thread to queue on */
         spinlock_t lock;
 
-        /* extra name for this worker */
+        /* extra name for this worker, used for current->name */
         char *name;
 };