xfs: attach iclog callbacks in xlog_cil_set_ctx_write_state()

Now that we have a mechanism to guarantee that the callbacks
attached to an iclog are owned by the context that attaches them
until they drop their reference to the iclog via
xlog_state_release_iclog(), we can attach callbacks to the iclog at
any time we have an active reference to the iclog.

xlog_state_get_iclog_space() always guarantees that the commit
record will fit in the iclog it returns, so we can move this IO
callback setting to xlog_cil_set_ctx_write_state(), record the
commit iclog in the context and remove the need for the commit iclog
to be returned by xlog_write() altogether.

This, in turn, allows us to move the wakeup for ordered commit
record writes up into xlog_cil_set_ctx_write_state(), too, because
we have been guaranteed that this commit record will be physically
located in the iclog before any waiting commit record at a higher
sequence number will be granted iclog space.

This further cleans up the post commit record write processing in
the CIL push code, especially as xlog_state_release_iclog() will now
clean up the context when shutdown errors occur.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

1 files changed, 16 insertions, 31 deletions

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 6ac5d52f573d..cc65b3a13ad2 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -933,7 +933,7 @@ xlog_write_unmount_record(
 	/* account for space used by record data */
 	ticket->t_curr_res -= sizeof(ulf);
 
-	return xlog_write(log, NULL, &vec, ticket, NULL, XLOG_UNMOUNT_TRANS);
+	return xlog_write(log, NULL, &vec, ticket, XLOG_UNMOUNT_TRANS);
 }
 
 /*
@@ -2380,8 +2380,7 @@ xlog_write_copy_finish(
 	int			*data_cnt,
 	int			*partial_copy,
 	int			*partial_copy_len,
-	int			log_offset,
-	struct xlog_in_core	**commit_iclog)
+	int			log_offset)
 {
 	int			error;
 
@@ -2400,27 +2399,20 @@ xlog_write_copy_finish(
 	*partial_copy = 0;
 	*partial_copy_len = 0;
 
-	if (iclog->ic_size - log_offset <= sizeof(xlog_op_header_t)) {
-		/* no more space in this iclog - push it. */
-		spin_lock(&log->l_icloglock);
-		xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
-		*record_cnt = 0;
-		*data_cnt = 0;
-
-		if (iclog->ic_state == XLOG_STATE_ACTIVE)
-			xlog_state_switch_iclogs(log, iclog, 0);
-		else
-			ASSERT(iclog->ic_state == XLOG_STATE_WANT_SYNC ||
-				xlog_is_shutdown(log));
-		if (!commit_iclog)
-			goto release_iclog;
-		spin_unlock(&log->l_icloglock);
-		ASSERT(flags & XLOG_COMMIT_TRANS);
-		*commit_iclog = iclog;
-	}
+	if (iclog->ic_size - log_offset > sizeof(xlog_op_header_t))
+		return 0;
 
-	return 0;
+	/* no more space in this iclog - push it. */
+	spin_lock(&log->l_icloglock);
+	xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
+	*record_cnt = 0;
+	*data_cnt = 0;
 
+	if (iclog->ic_state == XLOG_STATE_ACTIVE)
+		xlog_state_switch_iclogs(log, iclog, 0);
+	else
+		ASSERT(iclog->ic_state == XLOG_STATE_WANT_SYNC ||
+			xlog_is_shutdown(log));
 release_iclog:
 	error = xlog_state_release_iclog(log, iclog, 0);
 	spin_unlock(&log->l_icloglock);
@@ -2473,7 +2465,6 @@ xlog_write(
 	struct xfs_cil_ctx	*ctx,
 	struct xfs_log_vec	*log_vector,
 	struct xlog_ticket	*ticket,
-	struct xlog_in_core	**commit_iclog,
 	uint			optype)
 {
 	struct xlog_in_core	*iclog = NULL;
@@ -2602,8 +2593,7 @@ xlog_write(
 						       &record_cnt, &data_cnt,
 						       &partial_copy,
 						       &partial_copy_len,
-						       log_offset,
-						       commit_iclog);
+						       log_offset);
 			if (error)
 				return error;
 
@@ -2641,12 +2631,7 @@ next_lv:
 
 	spin_lock(&log->l_icloglock);
 	xlog_state_finish_copy(log, iclog, record_cnt, data_cnt);
-	if (commit_iclog) {
-		ASSERT(optype & XLOG_COMMIT_TRANS);
-		*commit_iclog = iclog;
-	} else {
-		error = xlog_state_release_iclog(log, iclog, 0);
-	}
+	error = xlog_state_release_iclog(log, iclog, 0);
 	spin_unlock(&log->l_icloglock);
 
 	return error;