diff mbox series

[12/14] xfs: use background worker pool when transactions can't get free space

Message ID 162812924890.2589546.999461658082207492.stgit@magnolia (mailing list archive)
State Accepted, archived
Headers show
Series xfs: deferred inode inactivation | expand

Commit Message

Darrick J. Wong Aug. 5, 2021, 2:07 a.m. UTC 
From: Darrick J. Wong <djwong@kernel.org>

In xfs_trans_alloc, if the block reservation call returns ENOSPC, we
call xfs_blockgc_free_space with a NULL icwalk structure to try to free
space.  Each frontend thread that encounters this situation starts its
own walk of the inode cache to see if it can find anything, which is
wasteful since we don't have any additional selection criteria.  For
this one common case, create a function that reschedules all pending
background work immediately and flushes the workqueue so that the scan
can run in parallel.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
 fs/xfs/xfs_icache.c |   28 ++++++++++++++++++++++++++++
 fs/xfs/xfs_icache.h |    1 +
 fs/xfs/xfs_trace.h  |    1 +
 fs/xfs/xfs_trans.c  |    5 +----
 4 files changed, 31 insertions(+), 4 deletions(-)

Comments

Dave Chinner Aug. 5, 2021, 5:42 a.m. UTC | #1 
On Wed, Aug 04, 2021 at 07:07:28PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@kernel.org>
> 
> In xfs_trans_alloc, if the block reservation call returns ENOSPC, we
> call xfs_blockgc_free_space with a NULL icwalk structure to try to free
> space.  Each frontend thread that encounters this situation starts its
> own walk of the inode cache to see if it can find anything, which is
> wasteful since we don't have any additional selection criteria.  For
> this one common case, create a function that reschedules all pending
> background work immediately and flushes the workqueue so that the scan
> can run in parallel.
> 
> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> ---
>  fs/xfs/xfs_icache.c |   28 ++++++++++++++++++++++++++++
>  fs/xfs/xfs_icache.h |    1 +
>  fs/xfs/xfs_trace.h  |    1 +
>  fs/xfs/xfs_trans.c  |    5 +----
>  4 files changed, 31 insertions(+), 4 deletions(-)

Yup, looks a bit more efficient to do it this way.

Reviewed-by: Dave Chinner <dchinner@redhat.com>
diff mbox series

Patch

diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 5ee1a084d36d..f5a4f4d64c50 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -1507,6 +1507,34 @@  xfs_blockgc_free_space(
 	return 0;
 }
 
+/*
+ * Reclaim all the free space that we can by scheduling the background blockgc
+ * and inodegc workers immediately and waiting for them all to clear.
+ */
+void
+xfs_blockgc_flush_all(
+	struct xfs_mount	*mp)
+{
+	struct xfs_perag	*pag;
+	xfs_agnumber_t		agno;
+
+	trace_xfs_blockgc_flush_all(mp, __return_address);
+
+	/*
+	 * For each blockgc worker, move its queue time up to now.  If it
+	 * wasn't queued, it will not be requeued.  Then flush whatever's
+	 * left.
+	 */
+	for_each_perag_tag(mp, agno, pag, XFS_ICI_BLOCKGC_TAG)
+		mod_delayed_work(pag->pag_mount->m_blockgc_wq,
+				&pag->pag_blockgc_work, 0);
+
+	for_each_perag_tag(mp, agno, pag, XFS_ICI_BLOCKGC_TAG)
+		flush_delayed_work(&pag->pag_blockgc_work);
+
+	xfs_inodegc_flush(mp);
+}
+
 /*
  * Run cow/eofblocks scans on the supplied dquots.  We don't know exactly which
  * quota caused an allocation failure, so we make a best effort by including
diff --git a/fs/xfs/xfs_icache.h b/fs/xfs/xfs_icache.h
index 8175148afd50..18c2d224aa78 100644
--- a/fs/xfs/xfs_icache.h
+++ b/fs/xfs/xfs_icache.h
@@ -59,6 +59,7 @@  int xfs_blockgc_free_dquots(struct xfs_mount *mp, struct xfs_dquot *udqp,
 		unsigned int iwalk_flags);
 int xfs_blockgc_free_quota(struct xfs_inode *ip, unsigned int iwalk_flags);
 int xfs_blockgc_free_space(struct xfs_mount *mp, struct xfs_icwalk *icm);
+void xfs_blockgc_flush_all(struct xfs_mount *mp);
 
 void xfs_inode_set_eofblocks_tag(struct xfs_inode *ip);
 void xfs_inode_clear_eofblocks_tag(struct xfs_inode *ip);
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index 1b1c288610af..0a179cfc35c0 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -202,6 +202,7 @@  DEFINE_FS_EVENT(xfs_fs_sync_fs);
 DEFINE_FS_EVENT(xfs_blockgc_start);
 DEFINE_FS_EVENT(xfs_blockgc_stop);
 DEFINE_FS_EVENT(xfs_blockgc_worker);
+DEFINE_FS_EVENT(xfs_blockgc_flush_all);
 
 DECLARE_EVENT_CLASS(xfs_ag_class,
 	TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno),
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index 87bffd12c20c..83abaa219616 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -295,10 +295,7 @@  xfs_trans_alloc(
 		 * Do not perform a synchronous scan because callers can hold
 		 * other locks.
 		 */
-		error = xfs_blockgc_free_space(mp, NULL);
-		if (error)
-			return error;
-
+		xfs_blockgc_flush_all(mp);
 		want_retry = false;
 		goto retry;
 	}