Merge tag 'for-6.3-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "Two patches fixing the problem with aync discard.

  The default settings had a low IOPS limit and processing a large batch
  to discard would take a long time. On laptops this can cause increased
  power consumption due to disk activity.

  As async discard has been on by default since 6.2 this likely affects
  a lot of users.

  Summary:

   - increase the default IOPS limit 10x which reportedly helped

   - setting the sysfs IOPS value to 0 now does not throttle anymore
     allowing the discards to be processed at full speed. Previously
     there was an arbitrary 6 hour target for processing the pending
     batch"

* tag 'for-6.3-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: reinterpret async discard iops_limit=0 as no delay
  btrfs: set default discard iops_limit to 1000

Author: torvalds

fs/btrfs/discard.c

@@ -56,11 +56,9 @@
 #define BTRFS_DISCARD_DELAY		(120ULL * NSEC_PER_SEC)
 #define BTRFS_DISCARD_UNUSED_DELAY	(10ULL * NSEC_PER_SEC)
 
-/* Target completion latency of discarding all discardable extents */
-#define BTRFS_DISCARD_TARGET_MSEC	(6 * 60 * 60UL * MSEC_PER_SEC)
 #define BTRFS_DISCARD_MIN_DELAY_MSEC	(1UL)
 #define BTRFS_DISCARD_MAX_DELAY_MSEC	(1000UL)
-#define BTRFS_DISCARD_MAX_IOPS		(10U)
+#define BTRFS_DISCARD_MAX_IOPS		(1000U)
 
 /* Monotonically decreasing minimum length filters after index 0 */
 static int discard_minlen[BTRFS_NR_DISCARD_LISTS] = {
@@ -577,6 +575,7 @@ void btrfs_discard_calc_delay(struct btrfs_discard_ctl *discard_ctl)
 	s32 discardable_extents;
 	s64 discardable_bytes;
 	u32 iops_limit;
+	unsigned long min_delay = BTRFS_DISCARD_MIN_DELAY_MSEC;
 	unsigned long delay;
 
 	discardable_extents = atomic_read(&discard_ctl->discardable_extents);
@@ -607,13 +606,19 @@ void btrfs_discard_calc_delay(struct btrfs_discard_ctl *discard_ctl)
 	}
 
 	iops_limit = READ_ONCE(discard_ctl->iops_limit);
-	if (iops_limit)
+
+	if (iops_limit) {
 		delay = MSEC_PER_SEC / iops_limit;
-	else
-		delay = BTRFS_DISCARD_TARGET_MSEC / discardable_extents;
+	} else {
+		/*
+		 * Unset iops_limit means go as fast as possible, so allow a
+		 * delay of 0.
+		 */
+		delay = 0;
+		min_delay = 0;
+	}
 
-	delay = clamp(delay, BTRFS_DISCARD_MIN_DELAY_MSEC,
-		      BTRFS_DISCARD_MAX_DELAY_MSEC);
+	delay = clamp(delay, min_delay, BTRFS_DISCARD_MAX_DELAY_MSEC);
 	discard_ctl->delay_ms = delay;
 
 	spin_unlock(&discard_ctl->lock);