xfs: make the log ticket ID available outside the log infrastructure

The ticket ID is needed to uniquely identify transactions when doing busy
extent matching. Delayed logging changes the lifecycle of busy extents with
respect to the transaction structure lifecycle. Hence we can no longer use
the transaction structure as a means of determining the owner of the busy
extent as it may be freed and reused while the busy extent is still active.

This commit provides the infrastructure to access the xlog_tid_t held in the
ticket from a transaction handle. This avoids the need for callers to peek
into the transaction and log structures to find this out.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h
index 229d1f36ba9a..05f205aac913 100644
--- a/fs/xfs/xfs_log.h
+++ b/fs/xfs/xfs_log.h
@@ -19,7 +19,6 @@
 #define __XFS_LOG_H__
 
 /* get lsn fields */
-
 #define CYCLE_LSN(lsn) ((uint)((lsn)>>32))
 #define BLOCK_LSN(lsn) ((uint)(lsn))
 
@@ -134,6 +133,7 @@ struct xlog_in_core;
 struct xlog_ticket;
 struct xfs_log_item;
 struct xfs_item_ops;
+struct xfs_trans;
 
 void    xfs_log_item_init(struct xfs_mount      *mp,
                         struct xfs_log_item     *item,
@@ -190,6 +190,8 @@ void	  xlog_iodone(struct xfs_buf *);
 struct xlog_ticket * xfs_log_ticket_get(struct xlog_ticket *ticket);
 void      xfs_log_ticket_put(struct xlog_ticket *ticket);
 
+xlog_tid_t xfs_log_get_trans_ident(struct xfs_trans *tp);
+
 #endif