[PATCH 5/6] xfs_scrub: make phase 4 go straight to fstrim if nothing to fix

From: "Darrick J. Wong" <djwong@kernel.org>
To: sandeen@sandeen.net, djwong@kernel.org
Cc: linux-xfs@vger.kernel.org
Subject: [PATCH 5/6] xfs_scrub: make phase 4 go straight to fstrim if nothing to fix
Date: Thu, 05 May 2022 09:08:09 -0700	[thread overview]
Message-ID: <165176688994.252160.6045763886457820977.stgit@magnolia> (raw)
In-Reply-To: <165176686186.252160.2880340500532409944.stgit@magnolia>

From: Darrick J. Wong <djwong@kernel.org>

If there's nothing to repair in phase 4, there's no need to hold up the
FITRIM call to do the summary count scan that prepares us to repair
filesystem metadata.  Rearrange this a bit.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
 scrub/phase4.c |   51 ++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 42 insertions(+), 9 deletions(-)

diff --git a/scrub/phase4.c b/scrub/phase4.c
index 6ed7210f..ad26d9d5 100644
--- a/scrub/phase4.c
+++ b/scrub/phase4.c
@@ -95,15 +95,32 @@ repair_everything(
 	if (aborted)
 		return ECANCELED;
 
-	pthread_mutex_lock(&ctx->lock);
-	if (ctx->corruptions_found == 0 && ctx->unfixable_errors == 0 &&
-	    want_fstrim) {
+	return 0;
+}
+
+/* Decide if we have any repair work to do. */
+static inline bool
+have_action_items(
+	struct scrub_ctx	*ctx)
+{
+	xfs_agnumber_t		agno;
+
+	for (agno = 0; agno < ctx->mnt.fsgeom.agcount; agno++) {
+		if (action_list_length(&ctx->action_lists[agno]) > 0)
+			return true;
+	}
+
+	return false;
+}
+
+/* Trim the unused areas of the filesystem if the caller asked us to. */
+static void
+trim_filesystem(
+	struct scrub_ctx	*ctx)
+{
+	if (want_fstrim)
 		fstrim(ctx);
-		progress_add(1);
-	}
-	pthread_mutex_unlock(&ctx->lock);
-
-	return 0;
+	progress_add(1);
 }
 
 /* Fix everything that needs fixing. */
@@ -113,6 +130,9 @@ phase4_func(
 {
 	int			ret;
 
+	if (!have_action_items(ctx))
+		goto maybe_trim;
+
 	/*
 	 * Check the summary counters early.  Normally we do this during phase
 	 * seven, but some of the cross-referencing requires fairly-accurate
@@ -123,7 +143,20 @@ phase4_func(
 	if (ret)
 		return ret;
 
-	return repair_everything(ctx);
+	ret = repair_everything(ctx);
+	if (ret)
+		return ret;
+
+	/*
+	 * If errors remain on the filesystem, do not trim anything.  We don't
+	 * have any threads running, so it's ok to skip the ctx lock here.
+	 */
+	if (ctx->corruptions_found || ctx->unfixable_errors == 0)
+		return 0;
+
+maybe_trim:
+	trim_filesystem(ctx);
+	return 0;
 }
 
 /* Estimate how much work we're going to do. */

