xfs: don't run speculative preallocation gc when fs is frozen

Now that we have the infrastructure to switch background workers on and
off at will, fix the block gc worker code so that we don't actually run
the worker when the filesystem is frozen, same as we do for deferred
inactivation.

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

1 files changed, 16 insertions, 4 deletions

diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 9ba537c82d07..41bd84fd9e87 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -211,6 +211,11 @@ static inline void
 xfs_blockgc_queue(
 	struct xfs_perag	*pag)
 {
+	struct xfs_mount	*mp = pag->pag_mount;
+
+	if (!xfs_is_blockgc_enabled(mp))
+		return;
+
 	rcu_read_lock();
 	if (radix_tree_tagged(&pag->pag_ici_root, XFS_ICI_BLOCKGC_TAG))
 		queue_delayed_work(pag->pag_mount->m_blockgc_wq,
@@ -1366,8 +1371,12 @@ xfs_blockgc_stop(
 	struct xfs_perag	*pag;
 	xfs_agnumber_t		agno;
 
-	for_each_perag_tag(mp, agno, pag, XFS_ICI_BLOCKGC_TAG)
+	if (!xfs_clear_blockgc_enabled(mp))
+		return;
+
+	for_each_perag(mp, agno, pag)
 		cancel_delayed_work_sync(&pag->pag_blockgc_work);
+	trace_xfs_blockgc_stop(mp, __return_address);
 }
 
 /* Enable post-EOF and CoW block auto-reclamation. */
@@ -1378,6 +1387,10 @@ xfs_blockgc_start(
 	struct xfs_perag	*pag;
 	xfs_agnumber_t		agno;
 
+	if (xfs_set_blockgc_enabled(mp))
+		return;
+
+	trace_xfs_blockgc_start(mp, __return_address);
 	for_each_perag_tag(mp, agno, pag, XFS_ICI_BLOCKGC_TAG)
 		xfs_blockgc_queue(pag);
 }
@@ -1457,13 +1470,12 @@ xfs_blockgc_worker(
 	struct xfs_mount	*mp = pag->pag_mount;
 	int			error;
 
-	if (!sb_start_write_trylock(mp->m_super))
-		return;
+	trace_xfs_blockgc_worker(mp, __return_address);
+
 	error = xfs_icwalk_ag(pag, XFS_ICWALK_BLOCKGC, NULL);
 	if (error)
 		xfs_info(mp, "AG %u preallocation gc worker failed, err=%d",
 				pag->pag_agno, error);
-	sb_end_write(mp->m_super);
 	xfs_blockgc_queue(pag);
 }