diff mbox series

[v4,04/12] btrfs: introduce a FORCE_COMMIT_TRANS flush operation

Message ID 9c471c554b07853524b5496c2ea1ed7a343349b1.1611695838.git.josef@toxicpanda.com (mailing list archive)
State New, archived
Headers show
Series Improve preemptive ENOSPC flushing | expand

Commit Message

Josef Bacik Jan. 26, 2021, 9:24 p.m. UTC 
Sole-y for preemptive flushing, we want to be able to force the
transaction commit without any of the ambiguity of
may_commit_transaction().  This is because may_commit_transaction()
checks tickets and such, and in preemptive flushing we already know
it'll be helpful, so use this to keep the code nice and clean and
straightforward.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/ctree.h             |  1 +
 fs/btrfs/space-info.c        | 14 ++++++++++++++
 include/trace/events/btrfs.h |  3 ++-
 3 files changed, 17 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 7d8660227520..90726954b883 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2740,6 +2740,7 @@  enum btrfs_flush_state {
 	ALLOC_CHUNK_FORCE	=	8,
 	RUN_DELAYED_IPUTS	=	9,
 	COMMIT_TRANS		=	10,
+	FORCE_COMMIT_TRANS	=	11,
 };
 
 int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c
index ff138cef7d0b..94c9534505c5 100644
--- a/fs/btrfs/space-info.c
+++ b/fs/btrfs/space-info.c
@@ -735,6 +735,14 @@  static void flush_space(struct btrfs_fs_info *fs_info,
 	case COMMIT_TRANS:
 		ret = may_commit_transaction(fs_info, space_info);
 		break;
+	case FORCE_COMMIT_TRANS:
+		trans = btrfs_join_transaction(root);
+		if (IS_ERR(trans)) {
+			ret = PTR_ERR(trans);
+			break;
+		}
+		ret = btrfs_commit_transaction(trans);
+		break;
 	default:
 		ret = -ENOSPC;
 		break;
@@ -1037,6 +1045,12 @@  static void btrfs_async_reclaim_metadata_space(struct work_struct *work)
  *   For data we start with alloc chunk force, however we could have been full
  *   before, and then the transaction commit could have freed new block groups,
  *   so if we now have space to allocate do the force chunk allocation.
+ *
+ * FORCE_COMMIT_TRANS
+ *   For use by the preemptive flusher.  We use this to bypass the ticketing
+ *   checks in may_commit_transaction, as we have more information about the
+ *   overall state of the system and may want to commit the transaction ahead of
+ *   actual ENOSPC conditions.
  */
 static const enum btrfs_flush_state data_flush_states[] = {
 	FLUSH_DELALLOC_WAIT,
diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h
index b0ea2a108be3..0cf02dfd4c01 100644
--- a/include/trace/events/btrfs.h
+++ b/include/trace/events/btrfs.h
@@ -99,7 +99,8 @@  struct btrfs_space_info;
 	EM( ALLOC_CHUNK,		"ALLOC_CHUNK")			\
 	EM( ALLOC_CHUNK_FORCE,		"ALLOC_CHUNK_FORCE")		\
 	EM( RUN_DELAYED_IPUTS,		"RUN_DELAYED_IPUTS")		\
-	EMe(COMMIT_TRANS,		"COMMIT_TRANS")
+	EM(COMMIT_TRANS,		"COMMIT_TRANS")			\
+	EMe(FORCE_COMMIT_TRANS,		"FORCE_COMMIT_TRANS")
 
 /*
  * First define the enums in the above macros to be exported to userspace via