Merge branch 'for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

Pull btrfs updates from Chris Mason:
 "Jeff Mahoney and Dave Sterba have a really nice set of cleanups in
  here, and Christoph pitched in corrections/improvements to make btrfs
  use proper helpers for bio walking instead of doing it by hand.

  There are some key fixes as well, including some long standing bugs
  that took forever to track down in btrfs_drop_extents and during
  balance"

* 'for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (77 commits)
  btrfs: limit async_work allocation and worker func duration
  Revert "Btrfs: adjust len of writes if following a preallocated extent"
  Btrfs: don't WARN() in btrfs_transaction_abort() for IO errors
  btrfs: opencode chunk locking, remove helpers
  btrfs: remove root parameter from transaction commit/end routines
  btrfs: split btrfs_wait_marked_extents into normal and tree log functions
  btrfs: take an fs_info directly when the root is not used otherwise
  btrfs: simplify btrfs_wait_cache_io prototype
  btrfs: convert extent-tree tracepoints to use fs_info
  btrfs: root->fs_info cleanup, access fs_info->delayed_root directly
  btrfs: root->fs_info cleanup, add fs_info convenience variables
  btrfs: root->fs_info cleanup, update_block_group{,flags}
  btrfs: root->fs_info cleanup, lock/unlock_chunks
  btrfs: root->fs_info cleanup, btrfs_calc_{trans,trunc}_metadata_size
  btrfs: pull node/sector/stripe sizes out of root and into fs_info
  btrfs: root->fs_info cleanup, io_ctl_init
  btrfs: root->fs_info cleanup, use fs_info->dev_root everywhere
  btrfs: struct reada_control.root -> reada_control.fs_info
  btrfs: struct btrfsic_state->root should be an fs_info
  btrfs: alloc_reserved_file_extent trace point should use extent_root
  ...

1 files changed, 58 insertions, 6 deletions

diff --git a/fs/btrfs/qgroup.h b/fs/btrfs/qgroup.h
index 1bc64c864b62..416ae8e1d23c 100644
--- a/fs/btrfs/qgroup.h
+++ b/fs/btrfs/qgroup.h
@@ -23,6 +23,34 @@
 #include "delayed-ref.h"
 
 /*
+ * Btrfs qgroup overview
+ *
+ * Btrfs qgroup splits into 3 main part:
+ * 1) Reserve
+ *    Reserve metadata/data space for incoming operations
+ *    Affect how qgroup limit works
+ *
+ * 2) Trace
+ *    Tell btrfs qgroup to trace dirty extents.
+ *
+ *    Dirty extents including:
+ *    - Newly allocated extents
+ *    - Extents going to be deleted (in this trans)
+ *    - Extents whose owner is going to be modified
+ *
+ *    This is the main part affects whether qgroup numbers will stay
+ *    consistent.
+ *    Btrfs qgroup can trace clean extents and won't cause any problem,
+ *    but it will consume extra CPU time, it should be avoided if possible.
+ *
+ * 3) Account
+ *    Btrfs qgroup will updates its numbers, based on dirty extents traced
+ *    in previous step.
+ *
+ *    Normally at qgroup rescan and transaction commit time.
+ */
+
+/*
  * Record a dirty extent, and info qgroup to update quota on it
  * TODO: Use kmem cache to alloc it.
  */
@@ -65,8 +93,8 @@ struct btrfs_delayed_extent_op;
 int btrfs_qgroup_prepare_account_extents(struct btrfs_trans_handle *trans,
 					 struct btrfs_fs_info *fs_info);
 /*
- * Insert one dirty extent record into @delayed_refs, informing qgroup to
- * account that extent at commit trans time.
+ * Inform qgroup to trace one dirty extent, its info is recorded in @record.
+ * So qgroup can account it at commit trans time.
  *
  * No lock version, caller must acquire delayed ref lock and allocate memory.
  *
@@ -74,14 +102,15 @@ int btrfs_qgroup_prepare_account_extents(struct btrfs_trans_handle *trans,
  * Return >0 for existing record, caller can free @record safely.
  * Error is not possible
  */
-int btrfs_qgroup_insert_dirty_extent_nolock(
+int btrfs_qgroup_trace_extent_nolock(
 		struct btrfs_fs_info *fs_info,
 		struct btrfs_delayed_ref_root *delayed_refs,
 		struct btrfs_qgroup_extent_record *record);
 
 /*
- * Insert one dirty extent record into @delayed_refs, informing qgroup to
- * account that extent at commit trans time.
+ * Inform qgroup to trace one dirty extent, specified by @bytenr and
+ * @num_bytes.
+ * So qgroup can account it at commit trans time.
  *
  * Better encapsulated version.
  *
@@ -89,10 +118,33 @@ int btrfs_qgroup_insert_dirty_extent_nolock(
  * Return <0 for error, like memory allocation failure or invalid parameter
  * (NULL trans)
  */
-int btrfs_qgroup_insert_dirty_extent(struct btrfs_trans_handle *trans,
+int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans,
 		struct btrfs_fs_info *fs_info, u64 bytenr, u64 num_bytes,
 		gfp_t gfp_flag);
 
+/*
+ * Inform qgroup to trace all leaf items of data
+ *
+ * Return 0 for success
+ * Return <0 for error(ENOMEM)
+ */
+int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans,
+				  struct btrfs_fs_info *fs_info,
+				  struct extent_buffer *eb);
+/*
+ * Inform qgroup to trace a whole subtree, including all its child tree
+ * blocks and data.
+ * The root tree block is specified by @root_eb.
+ *
+ * Normally used by relocation(tree block swap) and subvolume deletion.
+ *
+ * Return 0 for success
+ * Return <0 for error(ENOMEM or tree search error)
+ */
+int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans,
+			       struct btrfs_root *root,
+			       struct extent_buffer *root_eb,
+			       u64 root_gen, int root_level);
 int
 btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans,
 			    struct btrfs_fs_info *fs_info,