xfs: move the log ioend workqueue to struct xlog

Move the workqueue used for log I/O completions from struct xfs_mount
to struct xlog to keep it self contained in the log code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
[darrick: destroy the log workqueue after ensuring log ios are done]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 6880e2a..8a3b7cc 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -1489,11 +1489,19 @@ xlog_alloc_log(
 	*iclogp = log->l_iclog;			/* complete ring */
 	log->l_iclog->ic_prev = prev_iclog;	/* re-write 1st prev ptr */
 
+	log->l_ioend_workqueue = alloc_workqueue("xfs-log/%s",
+			WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_HIGHPRI, 0,
+			mp->m_fsname);
+	if (!log->l_ioend_workqueue)
+		goto out_free_iclog;
+
 	error = xlog_cil_init(log);
 	if (error)
-		goto out_free_iclog;
+		goto out_destroy_workqueue;
 	return log;
 
+out_destroy_workqueue:
+	destroy_workqueue(log->l_ioend_workqueue);
 out_free_iclog:
 	for (iclog = log->l_iclog; iclog; iclog = prev_iclog) {
 		prev_iclog = iclog->ic_next;
@@ -1690,7 +1698,7 @@ xlog_bio_end_io(
 {
 	struct xlog_in_core	*iclog = bio->bi_private;
 
-	queue_work(iclog->ic_log->l_mp->m_log_workqueue,
+	queue_work(iclog->ic_log->l_ioend_workqueue,
 		   &iclog->ic_end_io_work);
 }
 
@@ -1966,6 +1974,7 @@ xlog_dealloc_log(
 	}
 
 	log->l_mp->m_log = NULL;
+	destroy_workqueue(log->l_ioend_workqueue);
 	kmem_free(log);
 }	/* xlog_dealloc_log */
 
diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h
index b9c90ab..a20f5e9 100644
--- a/fs/xfs/xfs_log_priv.h
+++ b/fs/xfs/xfs_log_priv.h
@@ -357,6 +357,7 @@ struct xlog {
 	struct xfs_ail		*l_ailp;	/* AIL log is working with */
 	struct xfs_cil		*l_cilp;	/* CIL log is working with */
 	struct xfs_buftarg	*l_targ;        /* buftarg of log */
+	struct workqueue_struct	*l_ioend_workqueue; /* for I/O completions */
 	struct delayed_work	l_work;		/* background flush work */
 	uint			l_flags;
 	uint			l_quotaoffs_flag; /* XFS_DQ_*, for QUOTAOFFs */
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 448986d..4adb683 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -183,7 +183,6 @@ typedef struct xfs_mount {
 	struct workqueue_struct	*m_unwritten_workqueue;
 	struct workqueue_struct	*m_cil_workqueue;
 	struct workqueue_struct	*m_reclaim_workqueue;
-	struct workqueue_struct	*m_log_workqueue;
 	struct workqueue_struct *m_eofblocks_workqueue;
 	struct workqueue_struct	*m_sync_workqueue;
 
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 594c119..5c28fb2 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -840,16 +840,10 @@ xfs_init_mount_workqueues(
 	if (!mp->m_reclaim_workqueue)
 		goto out_destroy_cil;
 
-	mp->m_log_workqueue = alloc_workqueue("xfs-log/%s",
-			WQ_MEM_RECLAIM|WQ_FREEZABLE|WQ_HIGHPRI, 0,
-			mp->m_fsname);
-	if (!mp->m_log_workqueue)
-		goto out_destroy_reclaim;
-
 	mp->m_eofblocks_workqueue = alloc_workqueue("xfs-eofblocks/%s",
 			WQ_MEM_RECLAIM|WQ_FREEZABLE, 0, mp->m_fsname);
 	if (!mp->m_eofblocks_workqueue)
-		goto out_destroy_log;
+		goto out_destroy_reclaim;
 
 	mp->m_sync_workqueue = alloc_workqueue("xfs-sync/%s", WQ_FREEZABLE, 0,
 					       mp->m_fsname);
@@ -860,8 +854,6 @@ xfs_init_mount_workqueues(
 
 out_destroy_eofb:
 	destroy_workqueue(mp->m_eofblocks_workqueue);
-out_destroy_log:
-	destroy_workqueue(mp->m_log_workqueue);
 out_destroy_reclaim:
 	destroy_workqueue(mp->m_reclaim_workqueue);
 out_destroy_cil:
@@ -880,7 +872,6 @@ xfs_destroy_mount_workqueues(
 {
 	destroy_workqueue(mp->m_sync_workqueue);
 	destroy_workqueue(mp->m_eofblocks_workqueue);
-	destroy_workqueue(mp->m_log_workqueue);
 	destroy_workqueue(mp->m_reclaim_workqueue);
 	destroy_workqueue(mp->m_cil_workqueue);
 	destroy_workqueue(mp->m_unwritten_workqueue);