Commit f00c42dd authored by Josef Bacik's avatar Josef Bacik Committed by David Sterba
Browse files

btrfs: introduce a FORCE_COMMIT_TRANS flush operation 



Solely 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: default avatarNikolay Borisov <nborisov@suse.com>
Signed-off-by: default avatarJosef Bacik <josef@toxicpanda.com>
[ add comment ]
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 5deb17e1

fs/btrfs/ctree.h

+1 −0
Original line number Diff line number Diff line
@@ -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,

fs/btrfs/space-info.c

+14 −0
Original line number Diff line number Diff line
@@ -140,6 +140,12 @@ 
 *     be freed, plus any delayed work we may not have gotten rid of in the case

 *     of metadata.

 *

 *   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.

 *

 * OVERCOMMIT

 *

 *   Because we hold so many reservations for metadata we will allow you to
@@ -735,6 +741,14 @@ 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;

include/trace/events/btrfs.h

+2 −1
Original line number Diff line number Diff line
@@ -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